The Vertical Dynamics of Larval Chironomids on Artificial Substrates in Lake Lido (Bogor, Indonesia)

PubMed Central

Wardiatno, Yusli; Krisanti, Majariana

2013-01-01

The composition and abundance of chironomid larval communities was studied on artificial substrates in Lido Lake, located in Bogor, West Java, Indonesia. The lake is organically enriched as a result of fish farming activity. Seventy two artificial substrates were deployed at three depths (2.0, 3.5 and 5.0 m) at two sites: a cage culture site and a non-cage culture site (control). Larval chironomid larvae were collected 7, 14, 28 and 56 days after the artificial substrates were deployed. In addition, selected physical and chemical parameters of the water were simultaneously measured. Three chironomid subfamilies, the Chironominae, Tanypodinae and Orthocladiinae, were found at both sites. At the cage culture site, both diversity and total abundance were significantly higher at the 2.0 and 3.5 m depths than at the 5.0 m depth, but this was not the case at the non-cage culture site. Based on pooling of the data from all depths, a Mann-Whitney U test showed that the non-cage culture site had a significantly higher diversity and total abundance than the cage culture site. Dissolved oxygen (DO) and turbidity showed significant differences between the 2.0 m depth and the 2 greater depths at the cage culture site, whereas none of the environmental parameters showed significant differences among the three depths at the non-cage culture site. A comparison of the environmental parameters at the same depth at the two sites showed significant differences in turbidity, pH and DO. A Spearman rank correlation analysis at the cage culture site showed that abundance and DO were positively correlated, whereas abundance and turbidity were negatively correlated. However, only pH was negatively correlated with abundance at the non-cage culture site. PMID:24575246

Saccharomyces cerevisiae RNA Polymerase I Terminates Transcription at the Reb1 Terminator In Vivo

PubMed Central

Reeder, Ronald H.; Guevara, Palmira; Roan, Judith G.

1999-01-01

We have mapped transcription termination sites for RNA polymerase I in the yeast Saccharomyces cerevisiae. S1 nuclease mapping shows that the primary terminator is the Reb1p terminator located at +93 downstream of the 3′ end of 25S rRNA. Reverse transcription coupled with quantitative PCR shows that approximately 90% of all transcripts terminate at this site. Transcripts which read through the +93 site quantitatively terminate at a fail-safe terminator located further downstream at +250. Inactivation of Rnt1p (an RNase III involved in processing the 3′ end of 25S rRNA) greatly stabilizes transcripts extending to both sites and increases readthrough at the +93 site. In vivo assay of mutants of the Reb1p terminator shows that this site operates in vivo by the same mechanism as has previously been delineated through in vitro studies. PMID:10523625

Estimating Douglas-fir site quality from aerial photographs.

Treesearch

Grover A. Choate

1961-01-01

This study investigated the feasibility of developing a technique for estimating site index of Douglas-fir in the Pacific Northwest, using aerial photos and topographic maps. Physiographic features were used as indicators of site index. Analysis showed that although most of the features were highly significant as criteria for predicting site index, they explained less...

A genome-wide map of hyper-edited RNA reveals numerous new sites.

PubMed

Porath, Hagit T; Carmi, Shai; Levanon, Erez Y

2014-08-27

Adenosine-to-inosine editing is one of the most frequent post-transcriptional modifications, manifested as A-to-G mismatches when comparing RNA sequences with their source DNA. Recently, a number of RNA-seq data sets have been screened for the presence of A-to-G editing, and hundreds of thousands of editing sites identified. Here we show that existing screens missed the majority of sites by ignoring reads with excessive ('hyper') editing that do not easily align to the genome. We show that careful alignment and examination of the unmapped reads in RNA-seq studies reveal numerous new sites, usually many more than originally discovered, and in precisely those regions that are most heavily edited. Specifically, we discover 327,096 new editing sites in the heavily studied Illumina Human BodyMap data and more than double the number of detected sites in several published screens. We also identify thousands of new sites in mouse, rat, opossum and fly. Our results establish that hyper-editing events account for the majority of editing sites.

Spatial variability in recruitment of benthos near drilling sites in the Iheya North hydrothermal field in the Okinawa Trough

NASA Astrophysics Data System (ADS)

Nakamura, Masako; Nakajima, Yuichi; Watanabe, Hiromi Kayama; Sasaki, Takenori; Yamamoto, Hiroyuki; Mitarai, Satoshi

2018-05-01

Due to increasing anthropogenic impacts on deep-sea hydrothermal vent ecosystems, it is essential to understand population structure and maintenance through larval recruitment and recovery of vent faunas after disturbances. In this study, we quantified vent animal recruitment in the Okinawa Trough, in the western Pacific Ocean. This is the first study to investigate recruitment patterns at a man-made hydrothermal vent. Colonization plates were deployed at three sites. Site 1 manifested new hydrothermal shimmering with small chimneys, white bacterial mats, and some alvinocaridid shrimp that arrived after drilling. Site 2 showed no evidence of newly arrived foundation species after drilling, and Site 3 had pre-existing animal communities in the vicinity of the new vent. Twenty-two months after deployment, colonization plates were retrieved and recruited animals were inventoried. Species composition and abundance differed among sites, but relatively high similarity in species composition was observed at Sites 1 and 3, though not at Site 2. Newly established communities on the plates at Sites 1 and 2 (no pre-existing fauna) showed lower species richness and abundance than at Site 3. Differences in abundance and size-frequency distributions of major recruits on the plates (i.e. Lepetodrilus nux, Bathymodiolus spp.) suggest the importance of reproductive and early life-history characteristics in spatial variability of recruitment. Lepetodrilus nux populations established on the plates at Site 1 showed high genetic connectivity. These results illustrate the importance of localized recruitment, which may have a significant impact on sustainability of vent faunal populations, despite the existence of regional metapopulations.

PM2.5 Indoor Air Quality at Two Sites in London Ontario - A Case Study

NASA Astrophysics Data System (ADS)

Mates, A. V.; Xu, X.; Gilliland, J.; Maltby, M. J.

2010-12-01

Studies have shown an association between ambient fine particulate matter (PM2.5) and health impacts, particularly for the elderly and children. As part of a larger study, PM2.5 concentrations were measured using the DustTrak (Model 8520, TSI, St. Paul, MN, USA) at two schools within the city of London, Ontario (Canada). Site A was in a suburban environment while site B was in an urban setting. Monitoring took place for 3 weeks during winter (Feb. 16 - Mar. 8) and 3 weeks during spring (May 05 - 25) of 2010. The winter campaign monitored indoor PM2.5 only, while the spring campaign added outdoor monitors (PM2.5 and CO2) after the first week. Ten min. concentrations were used for analysis. Indoor measurements were split into weekday and weekend. For the same time interval, the outdoor concentrations showed mean values of 18 and 21 μg/m3 for sites A & B, respectively, both under the Canada Wide Standard of 30 μg/m3. Measurements at the two sites showed good associations (R^2 = 0.44), during the spring campaign. This indicates that the outdoor PM2.5 had similar sources. For indoor concentrations, Site B showed a significantly different mean concentration 5 times higher compared to site A during the winter ( 8.1 vs. 1.5 μg/m3 ) and 3 times higher (11.9 vs. 3.7 μg/m3) during the spring campaign. Since the outdoor concentrations were similar the large difference in indoor concentrations could be attributed to the following factors: site B being an older building, and the different physical characteristics between the two sites. The spring measurements showed an increase of 50% from weekday to weekend for site A and 22% for site B. The higher level of PM2.5 during weekends is possibly due to the infiltration of outdoor air while the ventilation/filtration system is shut off. During the winter campaign, Site A showed a 14% higher concentration during weekdays compared to weekends while site B weekend concentrations were 17% higher compared to weekday, which will be further investigated. The CO2 levels will be analyzed for the effect of outdoor air infiltration. The weekday data will be further split into activity and non-activity hours to explore the PM2.5 concentration increases associated with activity.

Multiple binding sites for transcriptional repressors can produce regular bursting and enhance noise suppression

NASA Astrophysics Data System (ADS)

Lengyel, Iván M.; Morelli, Luis G.

2017-04-01

Cells may control fluctuations in protein levels by means of negative autoregulation, where transcription factors bind DNA sites to repress their own production. Theoretical studies have assumed a single binding site for the repressor, while in most species it is found that multiple binding sites are arranged in clusters. We study a stochastic description of negative autoregulation with multiple binding sites for the repressor. We find that increasing the number of binding sites induces regular bursting of gene products. By tuning the threshold for repression, we show that multiple binding sites can also suppress fluctuations. Our results highlight possible roles for the presence of multiple binding sites of negative autoregulators.

A randomized comparative prospective study of platelet-rich plasma, platelet-rich fibrin, and hydroxyapatite as a graft material for mandibular third molar extraction socket healing.

PubMed

Dutta, Shubha Ranjan; Passi, Deepak; Singh, Purnima; Sharma, Sarang; Singh, Mahinder; Srivastava, Dhirendra

2016-01-01

The purpose of this study was to compare the efficacy of platelet-rich plasma (PRP), platelet-rich fibrin (PRF), and hydroxyapatite (HA) for reduction of pain and swelling, absence of dry socket, soft tissue healing, and bone regeneration after mandibular third molar extraction in human patients. Forty patients requiring extraction of mandibular third molars were randomly grouped as control, PRP, PRF, and HA-treated. The patients were assessed for postoperative pain, swelling, dry socket, and soft tissue healing on the 3 rd , 7 th , and 14 th day of postoperative periods depending on the standard methods. Radiological assessment of the extraction site was done at 1, 2, and 6 months interval to compare the change in bone density in the sockets in control and treated patients. Pain and swelling were less on PRP and PRF site when compared to HA and control site. PRP and PRF site showed better soft tissue healing when compared to HA and control site. Radiographic assessment showed comparatively lesser bone density values in PRP, PRF, and control site at 1, 2, and 6 months than HA site. Our study showed that PRP and PRF are better graft materials than HA regarding pain, swelling, dry socket, and soft tissue healing. Bone regeneration is induced promptly by HA as compared to other graft materials. However, a more elaborate study with a larger number of clinical cases is very much essential to be more conclusive regarding the efficacy of the graft materials.

A randomized comparative prospective study of platelet-rich plasma, platelet-rich fibrin, and hydroxyapatite as a graft material for mandibular third molar extraction socket healing

PubMed Central

Dutta, Shubha Ranjan; Passi, Deepak; Singh, Purnima; Sharma, Sarang; Singh, Mahinder; Srivastava, Dhirendra

2016-01-01

Aim: The purpose of this study was to compare the efficacy of platelet-rich plasma (PRP), platelet-rich fibrin (PRF), and hydroxyapatite (HA) for reduction of pain and swelling, absence of dry socket, soft tissue healing, and bone regeneration after mandibular third molar extraction in human patients. Materials and Methods: Forty patients requiring extraction of mandibular third molars were randomly grouped as control, PRP, PRF, and HA-treated. The patients were assessed for postoperative pain, swelling, dry socket, and soft tissue healing on the 3rd, 7th, and 14th day of postoperative periods depending on the standard methods. Radiological assessment of the extraction site was done at 1, 2, and 6 months interval to compare the change in bone density in the sockets in control and treated patients. Results: Pain and swelling were less on PRP and PRF site when compared to HA and control site. PRP and PRF site showed better soft tissue healing when compared to HA and control site. Radiographic assessment showed comparatively lesser bone density values in PRP, PRF, and control site at 1, 2, and 6 months than HA site. Conclusion: Our study showed that PRP and PRF are better graft materials than HA regarding pain, swelling, dry socket, and soft tissue healing. Bone regeneration is induced promptly by HA as compared to other graft materials. However, a more elaborate study with a larger number of clinical cases is very much essential to be more conclusive regarding the efficacy of the graft materials. PMID:28163478

Estimation of Vs30 Soil Profile Structure of Singapore from Microtremor Records

NASA Astrophysics Data System (ADS)

Walling, M. Y.; Megawati, K.; Zhu, C.

2012-04-01

Singapore lies at the southern tip of the Malay Peninsula, covering a land area of 600 km2 and with a population exceeding 5 million. Array microtremor recording were carried out in Singapore for 40 sites that encompasses the sites of all the major geological formations. The Spatial Autocorrelation (SPAC) method is employed to determine the phase velocity dispersion curves and subsequently inverted to determine the shallow shear-wave velocity (V s) and soil stratigraphy. The depth of penetration is generally about 30 m - 40 m for most of the sites. For the present study, the V s estimation is restricted to the upper 30 m of the soil (V s30), confirming with the IBC (2006). The Reclaimed Land and the young Quaternary soft soil deposit of Kallang Formation show low V s30 values ranging from 207 m/s - 247 m/s, belonging to site E and at the boundary of site E and D. The Old Alluvium formation shows higher V s30 values ranging from 362 m/s - 563 m/s and can be classified under site C. The estimated V s30 for the sedimentary sequence of Jurong Formation reveal site C classification, with the V s30 range from 317 m/s - 712 m/s. On the other hand, the Bukit Timah Granite body shows low V s30 ranging from 225 m/s - 387 m/s, with most of the sites concentrated under site D classification and few sites at the boundary of sites D and C, for the upper 30 m. This low V s30 value of the granitic body can be explained in the light of intense weathering that the granite body has undergone for the upper layer, which is also supported from borehole records. The SPAC results are compared with nearby borehole data and they show a good correlation for sites that have soft soil formation and for the weathered granite body. The correlation confirms the reliability of SPAC method that can be applied for highly populated urbanized places like Singapore. The present research finding will be useful for further studies of site response analysis, site characterization and ground motion simulation.

Spatial variations of sapwood chemistry with soil acidity in Appalachian forests. [Quercus rubra; Prunus serotina; Pinus strobus L. ; Tsuga canadensis; Quercus prinus; Carya glabra

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeWalle, D.R.; Swistock, B.R.; Sharpe, W.E.

Studies were conducted at five Appalchian sites to determine if chemical element concentrations in sapwood tree rings from six tree species varied with soil and soil leachate acidity. The most recent 5-yr-growth increment was extracted from 10 tree boles of each species at each site and analyzed for chemical content using plasma emission spectroscopy. Sapwood tree rings generally showed higher concentrations of Mn and lower concentrations of Sr at sites with lower soil pH. Differences in tree-ring concentrations for Ca and Mn among sites were also found in soil water samples at these sites. Significant differences in soil leachate Almore » between sites were not duplicated in tree rings. Sapwood tree-ring chemistry in red oak (Quercus rubra L.), black cherry (Prunus serotina Ehrh.), eastern white pine (pinus strobus L.) and eastern hemlock (Tsuga canadensis (L.) Carr.) was generally responsive to differences in soil chemistry between sites. Chestnut oak (Quercus prinus L.) and pignut hickory (Carya glabra (Mill.) Sweet) were the least responsive species tested. Overall, results show that several common tree species and selected elements are potentially useful for studying historic soil acidification trends at these study sites.« less

Community structure of aquatic insects in the Esparza River, Costa Rica.

PubMed

Herrera-Vásquez, Jonathan

2009-01-01

This study focused on the structure of the aquatic insect community in spatial and temporal scales in the Esparza River. The river was sampled for one full year throughout 2007. During the dry season low flow months, five sampling points were selected in two different habitats (currents and pools), with five replicates per sample site. During the wet season with peak rain, only the data in the "current habitat" were sampled at each site. Specimens present in the different substrates were collected and preserved in situ. A nested ANOVA was then applied to the data to determine richness and density as the response variables. The variations in temporal and spatial scales were analyzed using width, depth and discharge of the river, and then analyzed using a nested ANOVA. Only a correlation of 51% similarity in richness was found, while in spatial scale, richness showed significant variation between sampling sites, but not between habitats. However, the temporal scale showed significant differences between habitats. Density showed differences between sites and habitats during the dry season in the spatial scale, while in the temporal scale significant variation was found between sampling sites. Width varied between habitats during the dry season, but not between sampling points. Depth showed differences between sampling sites and season. This work studies the importance of community structure of aquatic insects in rivers, and its relevance for the quality of water in rivers and streams.

Using Temporal Modulation Sensitivity to Select Stimulation Sites for Processor MAPs in Cochlear Implant Listeners

PubMed Central

Garadat, Soha N.; Zwolan, Teresa A.; Pfingst, Bryan E.

2013-01-01

Previous studies in our laboratory showed that temporal acuity as assessed by modulation detection thresholds (MDTs) varied across activation sites and that this site-to-site variability was subject specific. Using two 10-channel MAPs, the previous experiments showed that processor MAPs that had better across-site mean (ASM) MDTs yielded better speech recognition than MAPs with poorer ASM MDTs tested in the same subject. The current study extends our earlier work on developing more optimal fitting strategies to test the feasibility of using a site-selection approach in the clinical domain. This study examined the hypothesis that revising the clinical speech processor MAP for cochlear implant (CI) recipients by turning off selected sites that have poorer temporal acuity and reallocating frequencies to the remaining electrodes would lead to improved speech recognition. Twelve CI recipients participated in the experiments. We found that site selection procedure based on MDTs in the presence of a masker resulted in improved performance on consonant recognition and recognition of sentences in noise. In contrast, vowel recognition was poorer with the experimental MAP than with the clinical MAP, possibly due to reduced spectral resolution when sites were removed from the experimental MAP. Overall, these results suggest a promising path for improving recipient outcomes using personalized processor-fitting strategies based on a psychophysical measure of temporal acuity. PMID:23881208

Studies on the regulation of the human E1 subunit of the 2-oxoglutarate dehydrogenase complex, including the identification of a novel calcium-binding site.

PubMed

Armstrong, Craig T; Anderson, J L Ross; Denton, Richard M

2014-04-15

The regulation of the 2-oxoglutarate dehydrogenase complex is central to intramitochondrial energy metabolism. In the present study, the active full-length E1 subunit of the human complex has been expressed and shown to be regulated by Ca2+, adenine nucleotides and NADH, with NADH exerting a major influence on the K0.5 value for Ca2+. We investigated two potential Ca2+-binding sites on E1, which we term site 1 (D114ADLD) and site 2 (E139SDLD). Comparison of sequences from vertebrates with those from Ca2+-insensitive non-vertebrate complexes suggest that site 1 may be the more important. Consistent with this view, a mutated form of E1, D114A, shows a 6-fold decrease in sensitivity for Ca2+, whereas variant ∆site1 (in which the sequence of site 1 is replaced by A114AALA) exhibits an almost complete loss of Ca2+ activation. Variant ∆site2 (in which the sequence is replaced with A139SALA) shows no measurable change in Ca2+ sensitivity. We conclude that site 1, but not site 2, forms part of a regulatory Ca2+-binding site, which is distinct from other previously described Ca2+-binding sites.

Mapping of epitopes and structural analysis of antigenic sites in the nucleoprotein of rabies virus.

PubMed

Goto, H; Minamoto, N; Ito, H; Ito, N; Sugiyama, M; Kinjo, T; Kawai, A

2000-01-01

Linear epitopes on the rabies virus nucleoprotein (N) recognized by six MAbs raised against antigenic sites I (MAbs 6-4, 12-2 and 13-27) and IV (MAbs 6-9, 7-12 and 8-1) were investigated. Based on our previous studies on sites I and IV, 24 consecutively overlapping octapeptides and N- and C-terminal-deleted mutant N proteins were prepared. Results showed that all three site I epitopes studied and two site IV epitopes (for MAbs 8-1 and 6-9) mapped to aa 358-367, and that the other site IV epitope of MAb 7-12 mapped to aa 375-383. Tests using chimeric and truncated proteins showed that MAb 8-1 also requires the N-terminal sequence of the N protein to recognize its binding region more efficiently. Immunofluorescence studies demonstrated that all three site I-specific MAbs and one site IV-specific MAb (7-12) stained the N antigen that was diffusely distributed in the whole cytoplasm; the other two site IV-specific MAbs (6-9 and 8-1) detected only the N antigen in the cytoplasmic inclusion bodies (CIB). An antigenic site II-specific MAb (6-17) also detected CIB-associated N antigen alone. Furthermore, the level of diffuse N antigens decreased after treatment of infected cells with cycloheximide. These results suggest that epitopes at site I are expressed on the immature form of the N protein, but epitope structures of site IV MAbs 6-9 and 8-1 are created and/or exposed only after maturation of the N protein.

The importance of site quality to backcross chestnut establishment success

Treesearch

C.C. Pinchot; A.A. Royo; M.P. Peters; S.E. Schlarbaum; S.L. Anagnostakis

2017-01-01

Short-term studies show that American chestnut (Castanea dentata) grows faster on mesic compared to xeric sites. Long-term impacts of site quality and corresponding moisture and nutrient availability on backcross chestnut establishment success and resistance to the chestnut blight fungus, Cryphonectria parasitica, however, have...

Impacts on Coralligenous Outcrop Biodiversity of a Dramatic Coastal Storm

PubMed Central

Teixidó, Núria; Casas, Edgar; Cebrián, Emma; Linares, Cristina; Garrabou, Joaquim

2013-01-01

Extreme events are rare, stochastic perturbations that can cause abrupt and dramatic ecological change within a short period of time relative to the lifespan of organisms. Studies over time provide exceptional opportunities to detect the effects of extreme climatic events and to measure their impacts by quantifying rates of change at population and community levels. In this study, we show how an extreme storm event affected the dynamics of benthic coralligenous outcrops in the NW Mediterranean Sea using data acquired before (2006–2008) and after the impact (2009–2010) at four different sites. Storms of comparable severity have been documented to occur occasionally within periods of 50 years in the Mediterranean Sea. We assessed the effects derived from the storm comparing changes in benthic community composition at sites exposed to and sheltered from this extreme event. The sites analyzed showed different damage from severe to negligible. The most exposed and impacted site experienced a major shift immediately after the storm, represented by changes in the species richness and beta diversity of benthic species. This site also showed higher compositional variability immediately after the storm and over the following year. The loss of cover of benthic species resulted between 22% and 58%. The damage across these species (e.g. calcareous algae, sponges, anthozoans, bryozoans, tunicates) was uneven, and those with fragile forms were the most impacted, showing cover losses up to 50 to 100%. Interestingly, small patches survived after the storm and began to grow slightly during the following year. In contrast, sheltered sites showed no significant changes in all the studied parameters, indicating no variations due to the storm. This study provides new insights into the responses to large and rare extreme events of Mediterranean communities with low dynamics and long-lived species, which are among the most threatened by the effects of global change. PMID:23326496

A Study of Ziegler–Natta Propylene Polymerization Catalysts by Spectroscopic Methods

PubMed Central

Tkachenko, Olga P.; Kucherov, Alexey V.; Kustov, Leonid M.; Virkkunen, Ville; Leinonen, Timo; Denifl, Peter

2017-01-01

Ziegler–Natta polymerization catalysts were characterized by a complex of surface- and bulk-sensitive methods (DRIFTS, XPS, ESR, and XAS = XANES + EXAFS). A diffuse-reflectance Fourier-transform IR spectroscopy (DRIFTS) study showed the presence of strong Lewis acid sites in different concentrations and absence of strong basic sites in the polymerization catalysts. X-ray photoelectron spectroscopy (XPS), electron-spin resonance (ESR), and (X-ray absorption near-edge structure (XANES) analysis revealed the presence of Ti4+, Ti3+, Ti2+, and Ti1+ species in the surface layers and in the bulk of catalysts. The samples under study differ drastically in terms of the number of ESR-visible paramagnetic sites. The EXAFS study shows the presence of a Cl atom as a nearest neighbor of the absorbing Ti atom. PMID:28772850

Trace Metal Content of Sediments Close to Mine Sites in the Andean Region

PubMed Central

Yacoub, Cristina; Pérez-Foguet, Agustí; Miralles, Nuria

2012-01-01

This study is a preliminary examination of heavy metal pollution in sediments close to two mine sites in the upper part of the Jequetepeque River Basin, Peru. Sediment concentrations of Al, As, Cd, Cu, Cr, Fe, Hg, Ni, Pb, Sb, Sn, and Zn were analyzed. A comparative study of the trace metal content of sediments shows that the highest concentrations are found at the closest points to the mine sites in both cases. The sediment quality analysis was performed using the threshold effect level of the Canadian guidelines (TEL). The sediment samples analyzed show that potential ecological risk is caused frequently at both sites by As, Cd, Cu, Hg, Pb, and Zn. The long-term influence of sediment metals in the environment is also assessed by sequential extraction scheme analysis (SES). The availability of metals in sediments is assessed, and it is considered a significant threat to the environment for As, Cd, and Sb close to one mine site and Cr and Hg close to the other mine site. Statistical analysis of sediment samples provides a characterization of both subbasins, showing low concentrations of a specific set of metals and identifies the main characteristics of the different pollution sources. A tentative relationship between pollution sources and possible ecological risk is established. PMID:22606058

Probing the emitter site of Renilla luciferase using small organic molecules; an attempt to understand the molecular architecture of the emitter site.

PubMed

Salehi, Farajollah; Emamzadeh, Rahman; Nazari, Mahboobeh; Rasa, Seyed Mohammad Mahdi

2016-12-01

Renilla luciferase is a sensitive enzyme and has wide applications in biotechnology such as drug screening. Previous studies have tried to show the catalytic residues, nevertheless, the accurate architecture and molecular behavior of its emitter site remains uncharacterized. In this study, the activity of Renilla luciferase, in the presence of two small organic molecules including dimethyl sulfoxide (DMSO) and isopropanol was considered and the structure was studied by circular dichroism (CD) and fluorescence spectroscopy. Moreover, the interaction of small organic molecules with the Renilla luciferase was studied using molecular dynamics simulations. Kinetics studies showed that at low concentration of DMSO (16.6-66mM) and isopropanol (19.3-76mM) the K m changed and a competitive inhibition pattern was observed. Moreover, spectroscopy studies reveled that the changes of activity of Renilla luciferase in the presence of low concentrations of small organic molecules was not associated with structural collapse or severe changes in the enzyme conformation. Molecular dynamics simulations indicated that DMSO and isopropanol, as probing molecules, were both able to bind to the emitter site and remained with the residues of the emitter site. Based on the probing data, the architecture of the emitter site in the "non-binding" model was proposed. Copyright © 2016 Elsevier B.V. All rights reserved.

First principles study of electronic and structural properties of single walled zigzag boron nitride nanotubes doped with the elements of group IV

NASA Astrophysics Data System (ADS)

Bahari, Ali; jalalinejad, Amir; Bagheri, Mosahhar; Amiri, Masoud

2017-11-01

In this paper, structural and electronic properties and stability of (10, 0) born nitride nanotube (BNNT) are considered within density functional theory by doping group IV elements of the periodic table. The HOMO-LUMO gap has been strongly modified and treated a dual manner by choosing B or N sites for dopant atoms. Formation energy calculation shows that B site doping is more stable than N site doping. Results also show that all dopants turn the pristine BNNT into a p-type semiconductor except for carbon-doped BNNT at B site.

Long-term (10 year) trends in the chemistry of urban streams

NASA Astrophysics Data System (ADS)

Groffman, P. M.; Band, L. E.; Belt, K. T.; Kaushal, S.; Fisher, G. T.

2010-12-01

Weekly sampling of eight streams in the Baltimore metropolitan area has been carried out since 1998 as part of the NSF funded Baltimore urban Long-Term Ecological Research (BES LTER) project. The BES watersheds include 100% forested and agricultural catchments and developed watersheds ranging from very low-density (<1% impervious surface) suburban watersheds serviced by septic systems to more dense (> 40% impervious surface) urban watersheds. Stream discharge is continuously monitored at these sites by the U.S. Geological Survey (USGS). Stream samples are collected weekly regardless of flow conditions (no bias towards storm versus baseflow) and analyzed for nitrate, total nitrogen (N), phosphate, total phosphorus (P), chloride and sulfate. Ten-year analysis of the BES long-term study sites reveals several interesting spatial and temporal patterns. For N, the highest concentrations were found in the agricultural and suburban watersheds, followed by the urban sites, and finally by the forested site. Organic N was most important as a proportion of total N in the urban and forested sites. Spatial patterns in P were more complex, with urban, suburban and agricultural sites having the highest values. Over the ten year record, many sites showed significant changes in N concentrations, but few sites showed consistent patterns in P. The patterns in N were quite variable however, with some sites showing striking increases, while others showed striking decreases. Most (7 of 8) sites showed a decrease in the proportion of organic N, the trend was significant at 4 of the sites. There were few trends in the proportion of organic P. Discharge was a significant driver of variation in N and P export at some (mostly smaller watersheds) sites, for some solutes, but was not an overwhelmingly important driver of temporal variation. Key factors driving long-term patterns include climate variation and efforts to improve urban stream water quality by municipal authorities.

Access site complications and puncture site pain following transradial coronary procedures: a correlational study.

PubMed

Cheng, Ka Yan; Chair, Sek Ying; Choi, Kai Chow

2013-10-01

Transradial coronary angiography (CA) and percutaneous coronary intervention (PCI) are gaining worldwide popularity due to the low incidence of major vascular complications and early mobilization of patients post procedures. Although post transradial access site complications are generally considered as minor in nature, they are not being routinely recorded in clinical settings. To evaluate the incidence of access site complications and level of puncture site pain experienced by patients undergoing transradial coronary procedures and to examine factors associated with access site complications occurrence and puncture site pain severity. A cross-sectional correlational study of 85 Chinese speaking adult patients scheduled for elective transradial CA and or PCI. Ecchymosis, bleeding, hematoma and radial artery occlusion (RAO) were assessed through observation, palpation and plethysmographic signal of pulse oximetry after coronary procedures. Puncture site pain was assessed with a 100mm Visual Analogue Scale. Factors that were related to access site complications and puncture site pain were obtained from medical records. Ecchymosis was the most commonly reported transradial access site complication in this study. Paired t-test showed that the level of puncture site pain at 24 h was significantly (p<0.001) lower than that at 3 h after the procedure. Stepwise multivariable regression showed that female gender and shorter sheath time were found to be significantly associated with bleeding during gradual deflation of compression device. Only longer sheath time was significantly associated with RAO. Female gender and larger volume of compression air were associated with the presence of ecchymosis and puncture site pain at 3 h after procedure, respectively. The study findings suggest that common access site complications post transradial coronary procedures among Chinese population are relatively minor in nature. Individual puncture site pain assessment during the period of hemostasis is important. Nurses should pay more attention to factors such as female gender, sheath time and volume of compression that are more likely to be associated with transradial access site complications and puncture site pain. Copyright © 2013 Elsevier Ltd. All rights reserved.

DDT Analysis of Wetland Sediments in Upper Escambia Bay, Florida

NASA Astrophysics Data System (ADS)

Hopko, M. N.; Wright, J.; Liebens, J.; Vaughan, P.

2017-12-01

Dichlorodiphenyltrichloroethane (DDT) was a commonly used pesticide from World War II through the 1960's. DDT is generally used to control mosquito populations and as an agricultural insecticide. The pesticide and its degradation products (DDD and DDE) can bioaccumulate within ecosystems having negative implications for animal and human health. Consequently, DDT usage was banned in the United States in 1973. In a contaminant study performed in Escambia Bay, Florida, in 2009, DDT was present in 25% of study sites, most of which were located in the upper bay wetlands. Concentrations were well above the Florida Department of Environmental Protection's (FDEP) Probable Effect Level (PEL) and ratios of DDT and its metabolites indicated a recent introduction to the system. A follow-up study performed in 2016 found no DDT, but did show DDE at several sites. The current study repeated sampling in May 2017 at sites from the 2009 and 2016 studies. Sediment samples were collected in triplicate using a ponar sampler and DDT, DDD and DDE were extracted using EPA methods 3540c and 3620c. Extracts were analyzed using a gas chromatograph with electron capture detection (GC-ECD) as per EPA method 8081c. Sediment was also analyzed for organic carbon and particle size using an elemental NC analyzer and a laser diffraction particle sizer. Results show the presence of breakdown products DDE and DDD at multiple sites, but no detectable levels of DDT at any site. Sampling sites with high levels of DDT contamination in 2009 show only breakdown products in both 2016 and 2017. Particle size has little influence on DDD or DDE concentrations but OC is a controlling factor as indicated for contaminated sites by Pearson correlations between OC and DDE and DDD of 0.82 and 0.92, respectively. The presence of only DDD and/or DDE in the 2016 and 2017 studies indicates that the parent, DDT, has not been re-introduced into the watershed since 2009 but is degrading in the environment.

Long-Term Changes in Musculoskeletal Pain Sites in the General Population: The HUNT Study.

PubMed

Mundal, Ingunn; Bjørngaard, Johan Håkon; Nilsen, Tom I L; Nicholl, Barbara I; Gråwe, Rolf W; Fors, Egil Andreas

2016-11-01

In a Norwegian prospective population-based cohort study, we examined whether the number of chronic musculoskeletal pain sites changed over an 11-year period, and if the number of pain sites at follow-up was associated with health-related and lifestyle factors at baseline. The study included data on 78,973 adults participating in the Nord-Trøndelag Health Study (HUNT) in 1995 to 1997 (HUNT2) and 2006 to 2008 (HUNT3). On the basis of 3 categories of baseline pain sites, associations between baseline health-related, lifestyle, and demographic factors and number of pain sites at follow-up were analyzed with linear regression models adjusted for age, sex, marital status, physical activity, education, and other chronic diseases. We also estimated within-subject associations. Regardless of pain extent at baseline, anxiety and/or depression, sleeping problems, smoking, and obesity were positively associated with number of pain sites at follow-up, whereas education and physical activity were inversely associated with number of pain sites. The within-subject analyses showed largely similar associations for the health-related factors, whereas associations of lifestyle factors were attenuated. The mean number of pain sites remained unchanged between the 2 surveys. Overall, our study revealed prospective associations between several factors and pain sites 11 years later, regardless of the number of pain sites at baseline. This prospective study examined the association between development of pain and risk factors in the general population, on the basis of 3 categories of baseline pain sites. It also examined how these factors influence possible long-term changes in pain within individuals. We showed that having no or few baseline pain sites may not differ in its risk factors compared with having multiple pain sites. This article provides an important contribution to the ongoing debate regarding the association between lifestyle, demographic, and psychosocial risk factors, versus the course of multisite chronic pain. Additionally, we provide discussion on potential directions for clinical relevance and further research. Copyright © 2016 American Pain Society. All rights reserved.

Sources of Site Differences in the Efficacy of a Multisite Clinical Trial: The Treatment of SSRI-Resistant Depression in Adolescents

ERIC Educational Resources Information Center

Spirito, Anthony; Abebe, Kaleab Z.; Iyengar, Satish; Brent, David; Vitiello, Benedetto; Clarke, Gregory; Wagner, Karen Dineen; Asarnow, Joan; Emslie, Graham; Keller, Martin

2009-01-01

Site differences in treatment outcomes are not often highlighted when the results of multisite randomized clinical trials (MRCTs) are reported. The primary analyses of a 6-site MRCT, the Treatment of SSRI-Resistant Depression in Adolescents (TORDIA) study, showed substantial variation by site in the performance of a medication-only condition and a…

Characterization of nicotine binding to the rat brain P/sub 2/ preparation: the identification of multiple binding sites which include specific up-regulatory site(s)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sloan, J.W.

1984-01-01

These studies show that nicotine binds to the rat brain P/sub 2/ preparation by saturable and reversible processes. Multiple binding sites were revealed by the configuration of saturation, kinetic and Scatchard plots. A least squares best fit of Scatchard data using nonlinear curve fitting programs confirmed the presence of a very high affinity site, an up-regulatory site, a high affinity site and one or two low affinity sites. Stereospecificity was demonstrated for the up-regulatory site where (+)-nicotine was more effective and for the high affinity site where (-)-nicotine had a higher affinity. Drugs which selectively up-regulate nicotine binding site(s) havemore » been identified. Further, separate very high and high affinity sites were identified for (-)- and (+)-(/sup 3/H)nicotine, based on evidence that the site density for the (-)-isomer is 10 times greater than that for the (+)-isomer at these sites. Enhanced nicotine binding has been shown to be a statistically significant phenomenon which appears to be a consequence of drugs binding to specific site(s) which up-regulate binding at other site(s). Although Scatchard and Hill plots indicate positive cooperatively, up-regulation more adequately describes the function of these site(s). A separate up-regulatory site is suggested by the following: (1) Drugs vary markedly in their ability to up-regulate binding. (2) Both the affinity and the degree of up-regulation can be altered by structural changes in ligands. (3) Drugs with specificity for up-regulation have been identified. (4) Some drugs enhance binding in a dose-related manner. (5) Competition studies employing cold (-)- and (+)-nicotine against (-)- and (+)-(/sup 3/H)nicotine show that the isomers bind to separate sites which up-regulate binding at the (-)- and (+)-nicotine high affinity sites and in this regard (+)-nicotine is more specific and efficacious than (-)-nicotine.« less

Brief and precarious lives: infant mortality in contrasting sites from medieval and post-medieval England (AD 850-1859).

PubMed

Lewis, Mary E; Gowland, Rebecca

2007-09-01

This study compares the infant mortality profiles of 128 infants from two urban and two rural cemetery sites in medieval England. The aim of this paper is to assess the impact of urbanization and industrialization in terms of endogenous or exogenous causes of death. In order to undertake this analysis, two different methods of estimating gestational age from long bone lengths were used: a traditional regression method and a Bayesian method. The regression method tended to produce more marked peaks at 38 weeks, while the Bayesian method produced a broader range of ages and were more comparable with the expected "natural" mortality profiles.At all the sites, neonatal mortality (28-40 weeks) outweighed post-neonatal mortality (41-48 weeks) with rural Raunds Furnells in Northamptonshire, showing the highest number of neonatal deaths and post-medieval Spitalfields, London, showing a greater proportion of deaths due to exogenous or environmental factors. Of the four sites under study, Wharram Percy in Yorkshire showed the most convincing "natural" infant mortality profile, suggesting the inclusion of all births at the site (i.e., stillbirths and unbaptised infants). (c) 2007 Wiley-Liss, Inc.

Multisite study of particle number concentrations in urban air.

PubMed

Harrison, Roy M; Jones, Alan M

2005-08-15

Particle number concentration data are reported from a total of eight urban site locations in the United Kingdom. Of these, six are central urban background sites, while one is an urban street canyon (Marylebone Road) and another is influenced by both a motorway and a steelworks (Port Talbot). The concentrations are generally of a similar order to those reported in the literature, although higher than those in some of the other studies. Highest concentrations are at the Marylebone Road site and lowest are at the Port Talbot site. The central urban background locations lie somewhere between with concentrations typically around 20 000 cm(-3). A seasonal pattern affects all sites, with highest concentrations in the winter months and lowest concentrations in the summer. Data from all sites show a diurnal variation with a morning rush hour peak typical of an anthropogenic pollutant. When the dilution effects of windspeed are accounted for, the data show little directionality at the central urban background sites indicating the influence of sources from all directions as might be expected if the major source were road traffic. At the London Marylebone Road site there is high directionality driven by the air circulation in the street canyon, and at the Port Talbot site different diurnal patterns are seen for particle number count and PM10 influenced by emissions from road traffic (particle number count) and the steelworks (PM10) and local meteorological factors. Hourly particle number concentrations are generally only weakly correlated to NO(x) and PM10, with the former showing a slightly closer relationship. Correlations between daily average particle number count and PM10 were also weak. Episodes of high PM10 concentration in summer typically show low particle number concentrations consistent with transport of accumulation mode secondary aerosol, while winter episodes are frequently associated with high PM10 and particle number count arising from poor dispersion of local primary emissions.

Effects of Interpersonal Skills Training on MRI Operations in a Saturated Market: A Randomized Trial.

PubMed

Ajam, Amna A; Nguyen, Xuan V; Kelly, Ronda A; Ladapo, Joseph A; Lang, Elvira V

2017-07-01

The aim of this study was to assess the effects of team training on operational efficiency during outpatient MRI. In this institutional review board-approved, HIPAA-compliant study, six MRI outpatient sites of a midwestern hospital system were randomized to serve as controls or have their teams trained in advanced communication skills. The fourth quarter of fiscal year 2015 was the trial baseline. The trial ended in the third quarter (Q3) of fiscal year 2016 (FY16). Equipment utilization (completed scans/available slots), hourly scan rates (total orders completed per machine per hour of operation), and no-show rates stratified by time were analyzed using the Cochran-Mantel-Haenszel method, with individual comparisons performed with Bonferroni correction. The study encompassed 27,425 MRI examinations. Overall volume peaked at baseline and then declined over the following quarters. Compared with baseline, untrained sites experienced significant drops in equipment utilization (P < .01 for the first quarter of FY16 and P < .0001 for the second quarter of FY16 and Q3 FY16), decreasing from 77% to 65% over the study period, corresponding to a decrease from 1.15 to 0.97 in hourly scan rates. For trained sites, these metrics showed no significant change, with maintenance of hourly scan rates of 1.23 and 1.27 and equipment utilization rates of 83% and 85% between baseline and Q3 FY16. No-show rates remained stable at trained sites but increased at untrained sites in the last two quarters (P < .05). Nationally benchmarked patient satisfaction percentile ranking gradually increased at trained sites from 56th at baseline to 70th and successively decreased at untrained sites from 66th to 44th. MRI outpatient facilities trained in advanced communication techniques may have more favorable operational efficiency than untrained sites in a saturated market. Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.

A novel Death Defying Domain in Met entraps the active site of Caspase-3 and blocks apoptosis in hepatocytes

PubMed Central

Ma, Jihong; Zou, Chunbin; Guo, Lida; Seneviratne, Danushka S.; Tan, Xinping; Kwon, Yong-Kook; An, Jiyan; Bowser, Robert; DeFrances, Marie C.; Zarnegar, Reza

2013-01-01

Met, the transmembrane tyrosine kinase receptor for hepatocyte growth factor (HGF) is known to function as a potent anti-apoptotic mediator in normal and neoplastic cells. Herein we report that intracellular cytoplasmic tail of Met has evolved to harbor a tandem pair of Caspase-3 cleavage sites, which bait, trap and disable the active site of Caspase-3, thereby blocking the execution of apoptosis. We call this Caspase-3 cleavage motif the ‘Death Defying Domain’ (DDD). This site consists of the following sequence: DNAD-DEVD-T (where the hyphens denote caspase cleavage sites). Through functional and mechanistic studies, we show that upon DDD cleavage by Caspase-3, the resulting DEVD-T peptide acts as a competitive inhibitor and entraps the active site of Caspase-3 akin to DEVD-CHO, which is a potent, synthetic inhibitor of Caspase-3 activity. By gain and loss-of-function studies using restoration of DDD expression in DDD deficient hepatocytic cells, we found that both Caspase-3 sites in DDD are necessary for inhibition of Caspase-3 and promotion of cell survival. Employing mutagenesis studies, we show that DDD could operate independently of Met’s enzymatic activity as determined by using kinase-dead human Met mutant constructs. Studies of both human liver cancer tissues and cell lines uncovered that DDD cleavage and entrapment of Caspase-3 by DDD occur in vivo, further proving that this site has physiological and pathophysiological relevance. Conclusion Our findings show that Met can directly inhibit Caspase-3 via a novel mechanism and promote hepato-cyte survival. Results presented here will further our understanding of the mechanisms that control not only normal tissue homeostasis but also abnormal tissue growth such as cancer and degenerative diseases in which apoptotic caspases are at play. PMID:24122846

A hybrid QM/MM simulation study of intramolecular proton transfer in the pyridoxal 5'-phosphate in the active site of transaminase: influence of active site interaction on proton transfer.

PubMed

Dutta Banik, Sindrila; Chandra, Amalendu

2014-09-25

Pyridoxal 5'-phosphate (PLP) Schiff base, a versatile cofactor, exhibits a tautomeric equilibrium that involves an intramolecular proton transfer between the N-protonated zwitterionic ketoenamine tautomer and the O-protonated covalent enolimine tautomer. It has been postulated that for the catalytic activity, the PLP has to be in the zwitterionic ketoenamine tautomeric form. However, the exact position of the tautomeric equilibrium of Schiff base in the active site of PLP-dependent enzyme is not known yet. In the present work, we investigated the tautomeric equilibrium for the external aldimine state of PLP aspartate (PLP-Asp) Schiff base in the active site of aspartate aminotransferase (AspAT) using combined quantum mechanical and molecular mechanical simulations. The main focus of the present study is to analyze the factors that control the tautomeric equilibrium in the active sites of various PLP-dependent enzymes. The results show that the ketoenamine tautomer is more preferred than the enolimine tautomer both in the gas and aqueous phases as well as in the active site of AspAT. Current simulations show that the active site of AspAT is more suitable for the ketoenamine tautomer compared to the enolimine tautomer. Interestingly, the Tyr225 acts as a proton donor to the phenolic oxygen in the ketoenamine tautomer, while in the covalent enolimine tautomer, it acts as a proton acceptor to the phenolic oxygen. Finally, the metadynamics study confirms this result. The calculated free energy barrier is about 7.5 kcal/mol. A comparative analysis of the microenvironment created by the active site residues of three different PLP-dependent enzymes (aspartate aminotransferase, Dopa decarboxylase, and Ala-racemase) has been carried out to understand the controlling factor(s) of the tautomeric equilibrium. The analysis shows that the intermolecular hydrogen bonding between active site residues and the phenolic oxygen of PLP shifts the tautomeric equilibrium toward the N-protonated ketoenamine tautomeric form.

Water Quality, Cyanobacteria, and Environmental Factors and Their Relations to Microcystin Concentrations for Use in Predictive Models at Ohio Lake Erie and Inland Lake Recreational Sites, 2013-14

USGS Publications Warehouse

Francy, Donna S.; Graham, Jennifer L.; Stelzer, Erin A.; Ecker, Christopher D.; Brady, Amie M. G.; Pam Struffolino,; Loftin, Keith A.

2015-11-06

The results of this study showed that water-quality and environmental variables are promising for use in site-specific daily or long-term predictive models. In order to develop more accurate models to predict toxin concentrations at freshwater lake sites, data need to be collected more frequently and for consecutive days in future studies.

A GIS-BASED MULTI-CRITERIA EVALUATION SYSTEM FOR SELECTION OF LANDFILL SITES: a case study from Abu Dhabi, United Arab Emirates

NASA Astrophysics Data System (ADS)

Issa, S. M.; Shehhi, B. Al

2012-07-01

Landfill sites receive 92% of total annual solid waste produced by municipalities in the emirate of Abu Dhabi. In this study, candidate sites for an appropriate landfill location for the Abu Dhabi municipal area are determined by integrating geographic information systems (GIS) and multi-criteria evaluation (MCE) analysis. To identify appropriate landfill sites, eight input map layers including proximity to urban areas, proximity to wells and water table depth, geology and topography, proximity to touristic and archeological sites, distance from roads network, distance from drainage networks, and land slope are used in constraint mapping. A final map was generated which identified potential areas showing suitability for the location of the landfill site. Results revealed that 30% of the study area was identified as highly suitable, 25% as suitable, and 45% as unsuitable. The selection of the final landfill site, however, requires further field research.

End-user perspectives on e-commerce and health care web site quality.

PubMed

Le Rouge, Cynthia; De Leo, Gianluca

2008-11-06

We explore and compare the importance of various quality dimensions for health care and e-commerce web sites. The results show that the importance of various quality attributes for all except four of ten quality dimensions studied differ between health care and e-commerce web sites. These results can help health care managers to improve and/or to guide the design of their web sites.

Ursolic acid derivatives as potential antidiabetic agents: In vitro, in vivo, and in silico studies.

PubMed

Guzmán-Ávila, Ricardo; Flores-Morales, Virginia; Paoli, Paolo; Camici, Guido; Ramírez-Espinosa, Juan José; Cerón-Romero, Litzia; Navarrete-Vázquez, Gabriel; Hidalgo-Figueroa, Sergio; Yolanda Rios, Maria; Villalobos-Molina, Rafael; Estrada-Soto, Samuel

2018-03-01

Hit, Lead & Candidate Discovery Protein tyrosine phosphatase 1B (PTP-1B) has attracted interest as a novel target for the treatment of type 2 diabetes, this because its role in the insulin-signaling pathway as a negative regulator. Thus, the aim of current work was to obtain seven ursolic acid derivatives as potential antidiabetic agents with PTP-1B inhibition as main mechanism of action. Furthermore, derivatives 1-7 were submitted in vitro to enzymatic PTP-1B inhibition being 3, 5, and 7 the most active compounds (IC 50  = 5.6, 4.7, and 4.6 μM, respectively). In addition, results were corroborated with in silico docking studies with PTP-1B orthosteric site A and extended binding site B, showed that 3 had polar and Van der Waals interactions in both sites with Lys120, Tyr46, Ser216, Ala217, Ile219, Asp181, Phe182, Gln262, Val49, Met258, and Gly259, showing a docking score value of -7.48 Kcal/mol, being more specific for site A. Moreover, compound 7 showed polar interaction with Gln262 and Van der Waals interactions with Ala217, Phe182, Ile219, Arg45, Tyr46, Arg47, Asp48, and Val49 with a predictive docking score of -6.43 kcal/mol, suggesting that the potential binding site could be localized in the site B adjacent to the catalytic site A. Finally, derivatives 2 and 7 (50 mg/kg) were selected to establish their in vivo antidiabetic effect using a noninsulin-dependent diabetes mice model, showing significant blood glucose lowering compared with control group (p < .05). © 2018 Wiley Periodicals, Inc.

Seismic response of soft deposits due to landslide: The Mission Peak, California, landslide

USGS Publications Warehouse

Hartzell, Stephen; Leeds, Alena L.; Jibson, Randall W.

2017-01-01

The seismic response of active and intermittently active landslides is an important issue to resolve to determine if such landslides present an elevated hazard in future earthquakes. To study the response of landslide deposits, seismographs were placed on the Mission Peak landslide in the eastern San Francisco Bay region for a period of one year. Numerous local and near‐regional earthquakes were recorded that reveal a complexity of seismic response phenomena using the horizontal‐to‐vertical spectral ratio method. At lower frequencies, a clear spectral peak is observed at 0.5 Hz common to all four stations in the array and is attributed to a surface topographic effect. At higher frequencies, other spectral peaks occur that are interpreted in terms of local deposits and structures. Site amplification from the standard reference site method shows the minimum amplification with a factor of 2, comparing a site on and off the landslide. A site located on relatively homogeneous deposits of loose soils shows a clear spectral peak associated with the thickness of the deposit. Another site on a talus‐filled graben near the headscarp shows possible 2D or 3D effects from subsurface topography or scattering within and between buried sandstone blocks. A third site on a massive partially detached block below the crown of the headscarp shows indications of resonance caused by the reverberation of shear waves within the block. The varied seismic response of different parts of this complex landslide is consistent with other studies which found that, although landslide response is commonly enhanced in the downslope direction of landslide movement, such a response does not occur uniformly or consistently. When it does occur, enhanced site response parallel to the direction of landslide movement would contribute to landslide reactivation during significant earthquakes.

Cold-induced vasoconstriction at forearm and hand skin sites: the effect of age.

PubMed

Kingma, B R M; Frijns, A J H; Saris, W H M; van Steenhoven, A A; van Marken Lichtenbelt, W D

2010-07-01

During mild cold exposure, elderly are at risk of hypothermia. In humans, glabrous skin at the hands is well adapted as a heat exchanger. Evidence exists that elderly show equal vasoconstriction due to local cooling at the ventral forearm, yet no age effects on vasoconstriction at hand skin have been studied. Here, we tested the hypotheses that at hand sites (a) elderly show equal vasoconstriction due to local cooling and (b) elderly show reduced response to noradrenergic stimuli. Skin perfusion and mean arterial pressure were measured in 16 young adults (Y: 18-28 years) and 16 elderly (E: 68-78 years). To study the effect of local vasoconstriction mechanisms local sympathetic nerve terminals were blocked by bretylium (BR). Baseline local skin temperature was clamped at 33 degrees C. Next, local temperature was reduced to 24 degrees C. After 15 min of local cooling, noradrenaline (NA) was administered to study the effect of neural vasoconstriction mechanisms. No significant age effect was observed in vasoconstriction due to local cooling at BR sites. After NA, vasoconstriction at the forearm showed a significant age effect; however, no significant age effect was found at the hand sites. [Change in CVC (% from baseline): Forearm Y: -76 +/- 3 vs. E: -60 +/- 5 (P < 0.01), dorsal hand Y: -74 +/- 4 vs. E: -72 +/- 4 (n.s.), ventral hand Y: -80 +/- 7 vs. E: -70 +/- 11 (n.s.)]. In conclusion, in contrast to results from the ventral forearm, elderly did not show a blunted response to local cooling and noradrenaline at hand skin sites. This indicates that at hand skin the noradrenergic mechanism of vasoconstriction is maintained with age.

Assessment of Uncertainties Related to Seismic Hazard Using Fuzzy Analysis

NASA Astrophysics Data System (ADS)

Jorjiashvili, N.; Yokoi, T.; Javakhishvili, Z.

2013-05-01

Seismic hazard analysis in last few decades has been become very important issue. Recently, new technologies and available data have been improved that helped many scientists to understand where and why earthquakes happen, physics of earthquakes, etc. They have begun to understand the role of uncertainty in Seismic hazard analysis. However, there is still significant problem how to handle existing uncertainty. The same lack of information causes difficulties to quantify uncertainty accurately. Usually attenuation curves are obtained in statistical way: regression analysis. Statistical and probabilistic analysis show overlapped results for the site coefficients. This overlapping takes place not only at the border between two neighboring classes, but also among more than three classes. Although the analysis starts from classifying sites using the geological terms, these site coefficients are not classified at all. In the present study, this problem is solved using Fuzzy set theory. Using membership functions the ambiguities at the border between neighboring classes can be avoided. Fuzzy set theory is performed for southern California by conventional way. In this study standard deviations that show variations between each site class obtained by Fuzzy set theory and classical way are compared. Results on this analysis show that when we have insufficient data for hazard assessment site classification based on Fuzzy set theory shows values of standard deviations less than obtained by classical way which is direct proof of less uncertainty.

X-ray and synchrotron methods in studies of cultural heritage sites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koval’chuk, M. V.; Yatsishina, E. B.; Blagov, A. E.

2016-09-15

X-ray and synchrotron methods that are most widely used in studies of cultural heritage objects (including archaeological sites)—X-ray diffraction analysis, X-ray spectroscopy, and visualization techniques— have been considered. The reported examples show high efficiency and informativeness of natural science studies when solving most diverse problems of archaeology, history, the study of art, museology, etc.

New insight into the binding modes of TNP-AMP to human liver fructose-1,6-bisphosphatase

NASA Astrophysics Data System (ADS)

Han, Xinya; Huang, Yunyuan; Zhang, Rui; Xiao, San; Zhu, Shuaihuan; Qin, Nian; Hong, Zongqin; Wei, Lin; Feng, Jiangtao; Ren, Yanliang; Feng, Lingling; Wan, Jian

2016-08-01

Human liver fructose-1,6-bisphosphatase (FBPase) contains two binding sites, a substrate fructose-1,6-bisphosphate (FBP) active site and an adenosine monophosphate (AMP) allosteric site. The FBP active site works by stabilizing the FBPase, and the allosteric site impairs the activity of FBPase through its binding of a nonsubstrate molecule. The fluorescent AMP analogue, 2‧,3‧-O-(2,4,6-trinitrophenyl)adenosine 5‧-monophosphate (TNP-AMP) has been used as a fluorescent probe as it is able to competitively inhibit AMP binding to the AMP allosteric site and, therefore, could be used for exploring the binding modes of inhibitors targeted on the allosteric site. In this study, we have re-examined the binding modes of TNP-AMP to FBPase. However, our present enzyme kinetic assays show that AMP and FBP both can reduce the fluorescence from the bound TNP-AMP through competition for FBPase, suggesting that TNP-AMP binds not only to the AMP allosteric site but also to the FBP active site. Mutagenesis assays of K274L (located in the FBP active site) show that the residue K274 is very important for TNP-AMP to bind to the active site of FBPase. The results further prove that TNP-AMP is able to bind individually to the both sites. Our present study provides a new insight into the binding mechanism of TNP-AMP to the FBPase. The TNP-AMP fluorescent probe can be used to exam the binding site of an inhibitor (the active site or the allosteric site) using FBPase saturated by AMP and FBP, respectively, or the K247L mutant FBPase.

New insight into the binding modes of TNP-AMP to human liver fructose-1,6-bisphosphatase.

PubMed

Han, Xinya; Huang, Yunyuan; Zhang, Rui; Xiao, San; Zhu, Shuaihuan; Qin, Nian; Hong, Zongqin; Wei, Lin; Feng, Jiangtao; Ren, Yanliang; Feng, Lingling; Wan, Jian

2016-08-05

Human liver fructose-1,6-bisphosphatase (FBPase) contains two binding sites, a substrate fructose-1,6-bisphosphate (FBP) active site and an adenosine monophosphate (AMP) allosteric site. The FBP active site works by stabilizing the FBPase, and the allosteric site impairs the activity of FBPase through its binding of a nonsubstrate molecule. The fluorescent AMP analogue, 2',3'-O-(2,4,6-trinitrophenyl)adenosine 5'-monophosphate (TNP-AMP) has been used as a fluorescent probe as it is able to competitively inhibit AMP binding to the AMP allosteric site and, therefore, could be used for exploring the binding modes of inhibitors targeted on the allosteric site. In this study, we have re-examined the binding modes of TNP-AMP to FBPase. However, our present enzyme kinetic assays show that AMP and FBP both can reduce the fluorescence from the bound TNP-AMP through competition for FBPase, suggesting that TNP-AMP binds not only to the AMP allosteric site but also to the FBP active site. Mutagenesis assays of K274L (located in the FBP active site) show that the residue K274 is very important for TNP-AMP to bind to the active site of FBPase. The results further prove that TNP-AMP is able to bind individually to the both sites. Our present study provides a new insight into the binding mechanism of TNP-AMP to the FBPase. The TNP-AMP fluorescent probe can be used to exam the binding site of an inhibitor (the active site or the allosteric site) using FBPase saturated by AMP and FBP, respectively, or the K247L mutant FBPase. Copyright © 2016 Elsevier B.V. All rights reserved.

Nitrogen oxides and ozone in Portugal: trends and ozone estimation in an urban and a rural site.

PubMed

Fernández-Guisuraga, José Manuel; Castro, Amaya; Alves, Célia; Calvo, Ana; Alonso-Blanco, Elisabeth; Blanco-Alegre, Carlos; Rocha, Alfredo; Fraile, Roberto

2016-09-01

This study provides an analysis of the spatial distribution and trends of NO, NO2 and O3 concentrations in Portugal between 1995 and 2010. Furthermore, an estimation model for daily ozone concentrations was developed for an urban and a rural site. NO concentration showed a significant decreasing trend in most urban stations. A decreasing trend in NO2 is only observed in the stations with less influence from emissions of primary NO2. Several stations showed a significant upward trend in O3 as a result of the decrease in the NO/NO2 ratio. In the northern rural region, ozone showed a strong correlation with wind direction, highlighting the importance of long-range transport. In the urban site, most of the variance is explained by the NO2/NOX ratio. The results obtained by the ozone estimation model in the urban site fit 2013 observed data. In the rural site, the estimated ozone during extreme events agrees with observed concentration.

Avian fruit preferences across a Puerto Rican forested landscape: pattern consistency and implications for seed removal.

PubMed

Carlo, Tomás A; Collazo, Jaime A; Groom, Martha J

2003-01-01

Avian fruit consumption may ensure plant reproductive success when frugivores show consistent preference patterns and effectively remove and disperse seeds. In this study we examined avian fruit preferences and their seed-removal services at five study sites in north-central Puerto Rico. At each site, we documented the diet of seven common fruit-eating avian species from February to September 1998. Using foraging observations and area-based estimates of fruit abundance, we examined preference patterns of birds. We found that 7 out of 68 fleshy-fruited plant species were responsible for most of the fruit diet of birds. Seventeen plant species were preferred and four of them were repeatedly preferred across several study sites and times by at least one avian species. Preferred plant species comprised a small percentage of fleshy fruits at each site (<15% in four out of five study sites), but showed extended phenology patterns. The quantity of seeds removed by frugivore species was not strictly related to preferences. Some frugivores showing no preference could effectively remove more seeds from plants at some locations than species exhibiting constancy in their patterns of preference. Only two frugivores, Euphonia musica and Vireo altiloquous, removed most of the seeds of plants for which they exhibited repeated preference across the landscape. Preference patterns, particularly those exhibiting consistency in space and time for plant species having prolonged fruiting periods, may have important mechanistic consequences for the persistence, succession, and regeneration of tropical plant communities.

Avian fruit preferences across a Puerto Rican forested landscape: Pattern consistency and implications for seed removal

USGS Publications Warehouse

Carlo, T.A.; Collazo, J.A.; Groom, Martha J.

2003-01-01

Avian fruit consumption may ensure plant reproductive success when frugivores show consistent preference patterns and effectively remove and disperse seeds. In this study we examined avian fruit preferences and their seed-removal services at five study sites in north-central Puerto Rico. At each site, we documented the diet of seven common fruit-eating avian species from February to September 1998. Using foraging observations and area-based estimates of fruit abundance, we examined preference patterns of birds. We found that 7 out of 68 fleshy-fruited plant species were responsible for most of the fruit diet of birds. Seventeen plant species were preferred and four of them were repeatedly preferred across several study sites and times by at least one avian species. Preferred plant species comprised a small percentage of fleshy fruits at each site (<15% in four out of five study sites), but showed extended phenology patterns. The quantity of seeds removed by frugivore species was not strictly related to preferences. Some frugivores showing no preference could effectively remove more seeds from plants at some locations than species exhibiting constancy in their patterns of preference. Only two frugivores, Euphonia musica and Vireo altiloquous, removed most of the seeds of plants for which they exhibited repeated preference across the landscape. Preference patterns, particularly those exhibiting consistency in space and time for plant species having prolonged fruiting periods, may have important mechanistic consequences for the persistence, succession, and regeneration of tropical plant communities.

Effects of urban green infrastructure (UGI) on local outdoor microclimate during the growing season.

PubMed

Wang, Yafei; Bakker, Frank; de Groot, Rudolf; Wörtche, Heinrich; Leemans, Rik

2015-12-01

This study analyzed how the variations of plant area index (PAI) and weather conditions alter the influence of urban green infrastructure (UGI) on microclimate. To observe how diverse UGIs affect the ambient microclimate through the seasons, microclimatic data were measured during the growing season at five sites in a local urban area in The Netherlands. Site A was located in an open space; sites B, C, and D were covered by different types and configurations of green infrastructure (grove, a single deciduous tree, and street trees, respectively); and site E was adjacent to buildings to study the effects of their façades on microclimate. Hemispherical photography and globe thermometers were used to quantify PAI and thermal comfort at both shaded and unshaded locations. The results showed that groves with high tree density (site B) have the strongest effect on microclimate conditions. Monthly variations in the differences of mean radiant temperature (∆Tmrt) between shaded and unshaded areas followed the same pattern as the PAI. Linear regression showed a significant positive correlation between PAI and ∆Tmrt. The difference of daily average air temperature (∆T a ) between shaded and unshaded areas was also positively correlated to PAI, but with a slope coefficient below the measurement accuracy (±0.5 °C). This study showed that weather conditions can significantly impact the effectiveness of UGI in regulating microclimate. The results of this study can support the development of appropriate UGI measures to enhance thermal comfort in urban areas.

Molecular interaction of 2,4-diacetylphloroglucinol (DAPG) with human serum albumin (HSA): The spectroscopic, calorimetric and computational investigation

NASA Astrophysics Data System (ADS)

Pragna Lakshmi, T.; Mondal, Moumita; Ramadas, Krishna; Natarajan, Sakthivel

2017-08-01

Drug molecule interaction with human serum albumin (HSA) affects the distribution and elimination of the drug. The compound, 2,4-diacetylphloroglucinol (DAPG) has been known for its antimicrobial, antiviral, antihelminthic and anticancer properties. However, its interaction with HSA is not yet reported. In this study, the interaction between HSA and DAPG was investigated through steady-state fluorescence, time-resolved fluorescence (TRF), circular dichroism (CD), Fourier transform infrared (FT-IR) spectroscopy, isothermal titration calorimetry (ITC), molecular docking and molecular dynamics simulation (MDS). Fluorescence spectroscopy results showed the strong quenching of intrinsic fluorescence of HSA due to interaction with DAPG, through dynamic quenching mechanism. The compound bound to HSA with reversible and moderate affinity which explained its easy diffusion from circulatory system to target tissue. The thermodynamic parameters from fluorescence spectroscopic data clearly revealed the contribution of hydrophobic forces but, the role of hydrogen bonds was not negligible according to the ITC studies. The interaction was exothermic and spontaneous in nature. Binding with DAPG reduced the helical content of protein suggesting the unfolding of HSA. Site marker fluorescence experiments revealed the change in binding constant of DAPG in the presence of site I (warfarin) but not site II marker (ibuprofen) which confirmed that the DAPG bound to site I. ITC experiments also supported this as site I marker could not bind to HSA-DAPG complex while site II marker was accommodated in the complex. In silico studies further showed the lowest binding affinity and more stability of DAPG in site I than in site II. Thus the data presented in this study confirms the binding of DAPG to the site I of HSA which may help in further understanding of pharmacokinetic properties of DAPG.

Work-site wellness programmes in Sweden: a cross-sectional study of physical activity, self-efficacy, and health.

PubMed

Gånedahl, H; Zsaludek Viklund, P; Carlén, K; Kylberg, E; Ekberg, J

2015-05-01

In Sweden, a work-site wellness programme implies reimbursing some of the expenses for health-promoting activities. Although work-site wellness programmes are readily available in Sweden, a large number of employees elect not to participate. The aim of this study was to investigate the association of physical activity, self-reported general health assessment and self-efficacy with participation in a work-site wellness programme. A cross-sectional study design was used. An online questionnaire was distributed to employees of a manufacturing company with 2500 employees in southwest Sweden. Those who took advantage of the work-site wellness programme assessed their general health as better and had higher assessment of physical activity. The study showed that being enlisted also implies a higher level of physical activity and general health; however, the effect sizes of these correlations were small. Self-efficacy, i.e. perceived behavioural control, was not associated with participation in the work-site wellness programme. However, self-efficacy was correlated with both general health assessment and physical activity. A regression analysis to determine explanatory contributions to the general health assessment score showed no significant contribution from participation in a work-site wellness programme, but was instead explained by perceived behavioural control and physical activity. Given the small effect size of the difference in physical activity between participators and non-participators in the work-site wellness programme, it is probable that only a small proportion of participators changed their health-promoting activities as a result of the work-site wellness programme. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Different thresholds for detecting osteophytes and joint space narrowing exist between the site investigators and the centralized reader in a multicenter knee osteoarthritis study—data from the Osteoarthritis Initiative

PubMed Central

Guermazi, Ali; Hunter, David J.; Li, Ling; Benichou, Olivier; Eckstein, Felix; Kwoh, C. Kent; Nevitt, Michael

2011-01-01

Objective To evaluate how the reading of knee radiographs by site investigators differs from that by an expert musculoskeletal radiologist who trained and validated them in a multicenter knee osteoarthritis (OA) study. Materials and methods A subset of participants from the Osteoarthritis Initiative progression cohort was studied. Osteophytes and joint space narrowing (JSN) were evaluated using Kellgren-Lawrence (KL) and Osteoarthritis Research Society International (OARSI) grading. Radiographs were read by site investigators, who received training and validation of their competence by an expert musculoskeletal radiologist. Radiographs were re-read by this radiologist, who acted as a central reader. For KL and OARSI grading of osteophytes, discrepancies between two readings were adjudicated by another expert reader. Results Radiographs from 96 subjects (49 women) and 192 knees (138 KL grade≥2) were included. The site reading showed moderate agreement for KL grading overall (kappa=0.52) and for KL≥2 (i.e., radiographic diagnosis of “definite OA”; kappa=0.41). For OARSI grading, the site reading showed substantial agreement for lateral and medial JSN (kappa=0.65 and 0.71), but only fair agreement for osteophytes (kappa=0.37). For KL grading, the adjudicator’s reading showed substantial agreement with the centralized reading (kappa=0.62), but only slight agreement with the site reading (kappa=0.10). Conclusion Site investigators over-graded osteophytes compared to the central reader and the adjudicator. Different thresholds for scoring of JSN exist even between experts. Our results suggest that research studies using radiographic grading of OA should use a centralized reader for all grading. PMID:21479521

Assessment of the Effects of Holding Time and Temperature on Escherichia coli Densities in Surface Water Samples

PubMed Central

Pope, Misty L.; Bussen, Michelle; Feige, Mary Ann; Shadix, Lois; Gonder, Sharon; Rodgers, Crystal; Chambers, Yildiz; Pulz, Jessica; Miller, Ken; Connell, Kevin; Standridge, Jon

2003-01-01

Escherichia coli is a routinely used microbiological indicator of water quality. To determine whether holding time and storage conditions had an effect on E. coli densities in surface water, studies were conducted in three phases, encompassing 24 sites across the United States and four commonly used monitoring methods. During all three phases of the study, E. coli samples were analyzed at time 0 and at 8, 24, 30, and 48 h after sample collection. During phase 1, when 4°C samples were evaluated by Colilert or by placing a membrane onto mFC medium followed by transfer to nutrient agar containing 4-methylumbelliferyl-β-d-glucuronide (mFC/NA-MUG), three of four sites showed no significant differences throughout the 48-h study. During phase 2, five of seven sites showed no significant difference between time 0 and 24 h by membrane filtration (mFC/NA-MUG). When evaluated by the Colilert method, five of seven sites showed no significant difference in E. coli density between time 0 and 48 h. During phase 3, 8 of 13 sites showed no significant differences in E. coli densities between time 0 and the 48-h holding time, regardless of method. Based on the results of these studies, it appears that if samples are held below 10°C and are not allowed to freeze, most surface water E. coli samples analyzed by commonly used methods beyond 8 h after sample collection can generate E. coli data comparable to those generated within 8 h of sample collection. Notwithstanding this conclusion, E. coli samples collected from surface waters should always be analyzed as soon as possible. PMID:14532081

Chlorhexidine controlled-release profile after EDTA root surface etching: an in vivo study.

PubMed

Gamal, Ahmed Y; Kumper, Radi M; Sadek, Hesham S; El Destawy, Mahmoud T

2011-05-01

The main objective of the present study was to quantify chlorhexidine (CHX) release after the use of CHX-EDTA root surface treatment as a local-delivery antimicrobial vehicle. Twenty non-smoking patients clinically diagnosed as having moderate-to-severe chronic periodontitis were selected to participate in this study. After cause-related therapy, one site in every patient received defect overfill with CHX gel 2% (20 sites). In addition, twenty contralateral sites received defect fill of CHX gel after 3 minutes of 24% EDTA gel root surface etching (20 sites). Gingival crevicular fluid samples were collected at 1, 3, 7, and 14 days post-therapy. The CHX-EDTA group showed statistically significantly higher levels of CHX than those of the control group at 1, 3, and 7 days. At 14 days, the CHX-EDTA group showed 0.8 mg/mL values. The use of CHX-EDTA root surface treatment as a local-delivery antimicrobial improves CHX substantivity.

Lateral variation in geochemistry, petrology, and palynology in the Elswick coal bed, Pike County, Kentucky

USGS Publications Warehouse

Hower, J.C.; Ruppert, L.F.; Eble, C.F.

2007-01-01

The Middle Pennsylvanian/Langsettian (Westphalian A) Elswick coal bed, correlative to the Upper Banner of Virginia, is a rare example of a mined high-sulfur (> 2%) coal in Eastern Kentucky, a region known for low-sulfur coals. To characterize lateral variation in the geochemistry, petrography, and palynology of the Elswick coal bed, three sites were sampled along a southeast-northwest transect within a single mine. At the southeastern site, the lower 101??cm of the 116-cm thick coal is dull, generally dominated by durain and dull clarain. While all benches at this site fit within the previously-defined "mixed palynoflora - moderate/low vitrinite group," suggesting a stressed environment of deposition, the palynology of the benches of the dull interval show greater diversity than might be expected just from the petrology. Lithology is generally similar between the sites, but each site has some differences in the petrology. Overall, the coal bed shows significant lateral variation in properties at the mine scale, some of which can be attributed to the gain or loss of upper and lower lithologies, either through an actual physical merging or through the change in character of lithotypes. Sulfur content varies between the three sites examined for this study. Site 3, located in the northwestern portion of the study area is characterized by a strikingly high sulfur zone (7.45%) in the middle of the coal bed, a feature missing at the other sites. Pyrite and marcasite, in a mid-seam lithotype at the northwestern site (site 3), show signs of overgrowths, indicating multiple generations of sulfide emplacement. The high-sulfur site 3 lithologies all have massive overgrowths of euhedral and framboidal pyrite, fracture- and cleat-fill pyrite, and sulfide emplacement in fusinite lumens. Sulfur is high throughout the mine area, but variations are evident in the extent of secondary growth of sulfides. ?? 2006 Elsevier B.V. All rights reserved.

Periodontal and endodontic pathology delays extraction socket healing in a canine model

PubMed Central

2017-01-01

Purpose The aim of the present exploratory study was to evaluate extraction socket healing at sites with a history of periodontal and endodontic pathology. Methods The mandibular 4th premolar teeth in 5 adult beagle dogs served as experimental units. Periodontal and endodontic lesions were induced in 1 premolar site in each animal using wire ligatures and pulpal exposure over 3 months (diseased sites). The contralateral premolar sites served as healthy controls. The mandibular 4th premolar teeth were then extracted with minimal trauma, followed by careful wound debridement. The animals were sacrificed at days 1, 7, 30, 60, and 90 post-extraction for analysis, and the healing patterns at the healthy and diseased extraction sites were compared using radiography, scanning electron microscopy, histology, and histometry. Results During the first 7 days of healing, a significant presence of inflammatory granulation tissue was noted at the diseased sites (day 1), along with a slightly accelerated rate of fibrin clot resolution on day 7. On day 30, the diseased extraction sites showed a greater percentage of persistent fibrous connective tissue, and an absence of bone marrow formation. In contrast, healthy sites showed initial signs of bone marrow formation on day 30, and subsequently a significantly greater proportion of mature bone marrow formation on both days 60 and 90. Radiographs exhibited sclerotic changes adjoining apical endodontic lesions, with scanning electron microscopy showing collapsed Volkmann canals protruding from these regions in the diseased sites. Furthermore, periodontal ligament fibers exhibited a parallel orientation to the alveolar walls of the diseased sites, in contrast to a perpendicular arrangement in the healthy sites. Conclusions Within the limitations of this study, it appears that a history of periodontal and endodontic pathology may critically affect bone formation and maturation, leading to delayed and compromised extraction socket healing. PMID:28680710

Analysis of socket preservation using polylactide and polyglycolide (PLA-PGA) sponge: a clinical, radiographic, and histologic study.

PubMed

Madan, Rohit; Mohan, Ranjana; Bains, Vivek K; Gupta, Vivek; Singh, G P; Madan, Mani

2014-01-01

The aim of this study was to evaluate the extraction socket healing and dimensional changes following alveolar ridge preservation using polylactide and polyglycolide (PLA-PGA) sponge. Fifteen patients were selected for alveolar socket preservation immediately following tooth extraction. Monoradicular maxillary and mandibular teeth were evaluated. The selected sockets had intact sockets walls with a minimum of 7 mm of residual alveolar bone height. The test sites were thoroughly debrided and grafted with PLA-PGA sponge, while the control sites underwent natural healing. Computed tomography (CT) measurements were taken at baseline and 6 months. After 6 months of healing, final CT measurements were performed, and trephine core biopsy specimens were obtained for histologic analysis. Implants were placed immediately after biopsy harvesting. All subjects completed the study, and all sites healed without adverse events and allowed for implant placement. The mean difference in socket height, width, and density after 6 months was statistically significantly higher in the test sites compared with control sites. Clinical measurement at the midbuccal site of the alveolar socket showed a mean loss of 2.45 ± 0.67 mm in the control group, compared with a mean gain of 1.28 ± 0.58 mm in the test group. All test sites showed minimal ridge alterations, and statistically significant differences were observed between the test and control sites with respect to bone composition and horizontal and vertical bone loss, indicating that PLA-PGA sponge is suitable for alveolar ridge preservation.

High-Affinity Quasi-Specific Sites in the Genome: How the DNA-Binding Proteins Cope with Them

PubMed Central

Chakrabarti, J.; Chandra, Navin; Raha, Paromita; Roy, Siddhartha

2011-01-01

Many prokaryotic transcription factors home in on one or a few target sites in the presence of a huge number of nonspecific sites. Our analysis of λ-repressor in the Escherichia coli genome based on single basepair substitution experiments shows the presence of hundreds of sites having binding energy within 3 Kcal/mole of the OR1 binding energy, and thousands of sites with binding energy above the nonspecific binding energy. The effect of such sites on DNA-based processes has not been fully explored. The presence of such sites dramatically lowers the occupation probability of the specific site far more than if the genome were composed of nonspecific sites only. Our Brownian dynamics studies show that the presence of quasi-specific sites results in very significant kinetic effects as well. In contrast to λ-repressor, the E. coli genome has orders of magnitude lower quasi-specific sites for GalR, an integral transcription factor, thus causing little competition for the specific site. We propose that GalR and perhaps repressors of the same family have evolved binding modes that lead to much smaller numbers of quasi-specific sites to remove the untoward effects of genomic DNA. PMID:21889449

Changes versus homeostasis in alpine and sub-alpine vegetation over three decades in the sub-arctic.

PubMed

Hedenås, Henrik; Carlsson, Bengt A; Emanuelsson, Urban; Headley, Alistair D; Jonasson, Christer; Svensson, Brita M; Callaghan, Terry V

2012-01-01

Plant species distributions are expected to shift and diversity is expected to decline as a result of global climate change, particularly in the Arctic where climate warming is amplified. We have recorded the changes in richness and abundance of vascular plants at Abisko, sub-Arctic Sweden, by re-sampling five studies consisting of seven datasets; one in the mountain birch forest and six at open sites. The oldest study was initiated in 1977-1979 and the latest in 1992. Total species number increased at all sites except for the birch forest site where richness decreased. We found no general pattern in how composition of vascular plants has changed over time. Three species, Calamagrostis lapponica, Carex vaginata and Salix reticulata, showed an overall increase in cover/frequency, while two Equisetum taxa decreased. Instead, we showed that the magnitude and direction of changes in species richness and composition differ among sites.

Multisite Reliability of Cognitive BOLD Data

PubMed Central

Brown, Gregory G.; Mathalon, Daniel H.; Stern, Hal; Ford, Judith; Mueller, Bryon; Greve, Douglas N.; McCarthy, Gregory; Voyvodic, Jim; Glover, Gary; Diaz, Michele; Yetter, Elizabeth; Burak Ozyurt, I.; Jorgensen, Kasper W.; Wible, Cynthia G.; Turner, Jessica A.; Thompson, Wesley K.; Potkin, Steven G.

2010-01-01

Investigators perform multi-site functional magnetic resonance imaging studies to increase statistical power, to enhance generalizability, and to improve the likelihood of sampling relevant subgroups. Yet undesired site variation in imaging methods could off-set these potential advantages. We used variance components analysis to investigate sources of variation in the blood oxygen level dependent (BOLD) signal across four 3T magnets in voxelwise and region of interest (ROI) analyses. Eighteen participants traveled to four magnet sites to complete eight runs of a working memory task involving emotional or neutral distraction. Person variance was more than 10 times larger than site variance for five of six ROIs studied. Person-by-site interactions, however, contributed sizable unwanted variance to the total. Averaging over runs increased between-site reliability, with many voxels showing good to excellent between-site reliability when eight runs were averaged and regions of interest showing fair to good reliability. Between-site reliability depended on the specific functional contrast analyzed in addition to the number of runs averaged. Although median effect size was correlated with between-site reliability, dissociations were observed for many voxels. Brain regions where the pooled effect size was large but between-site reliability was poor were associated with reduced individual differences. Brain regions where the pooled effect size was small but between-site reliability was excellent were associated with a balance of participants who displayed consistently positive or consistently negative BOLD responses. Although between-site reliability of BOLD data can be good to excellent, acquiring highly reliable data requires robust activation paradigms, ongoing quality assurance, and careful experimental control. PMID:20932915

Kinetic analysis of bypass of abasic site by the catalytic core of yeast DNA polymerase eta.

PubMed

Yang, Juntang; Wang, Rong; Liu, Binyan; Xue, Qizhen; Zhong, Mengyu; Zeng, Hao; Zhang, Huidong

2015-09-01

Abasic sites (Apurinic/apyrimidinic (AP) sites), produced ∼ 50,000 times/cell/day, are very blocking and miscoding. To better understand miscoding mechanisms of abasic site for yeast DNA polymerase η, pre-steady-state nucleotide incorporation and LC-MS/MS sequence analysis of extension product were studied using pol η(core) (catalytic core, residues 1-513), which can completely eliminate the potential effects of the C-terminal C2H2 motif of pol η on dNTP incorporation. The extension beyond the abasic site was very inefficient. Compared with incorporation of dCTP opposite G, the incorporation efficiencies opposite abasic site were greatly reduced according to the order of dGTP > dATP > dCTP and dTTP. Pol η(core) showed no fast burst phase for any incorporation opposite G or abasic site, suggesting that the catalytic step is not faster than the dissociation of polymerase from DNA. LC-MS/MS sequence analysis of extension products showed that 53% products were dGTP misincorporation, 33% were dATP and 14% were -1 frameshift, indicating that Pol η(core) bypasses abasic site by a combined G-rule, A-rule and -1 frameshift deletions. Compared with full-length pol η, pol η(core) relatively reduced the efficiency of incorporation of dCTP opposite G, increased the efficiencies of dNTP incorporation opposite abasic site and the exclusive incorporation of dGTP opposite abasic site, but inhibited the extension beyond abasic site, and increased the priority in extension of A: abasic site relative to G: abasic site. This study provides further understanding in the mutation mechanism of abasic sites for yeast DNA polymerase η. Copyright © 2015 Elsevier B.V. All rights reserved.

Impacts of ocean acidification on coral calcification: experimental results from a field study around submarine springs

NASA Astrophysics Data System (ADS)

Paytan, A.; Martínez Fernández, A.; Varona, N.

2017-12-01

Reef building corals are facing the effects of ocean acidification on calcification. Atmospheric carbon dioxide dissolves into the oceans and decreases the pH and the availability of carbonate ions in seawater. Carbonate ions are used by calcifying corals to create their calcium carbonate exoskeletons in the form of aragonite. As carbon dioxide emissions increase, corals may have problems precipitating their aragonite skeleton in low carbonate saturation seawater. Natural submarine groundwater springs discharge low pH seawater into the Caribbean Sea, in the Yucatan Peninsula (Mexico). These submarine springs serve as a natural laboratory to study the effects of low aragonite saturation water on coral growth. Here we show the skeletal growth parameters of three coral species under an in situ ocean acidification experiment. Nubbins of Porites porites, Porites astreoides and Siderastrea radians were collected at low pH springs and control sites and reciprocally transplanted into a low pH discharge site and into a control site not impacted by discharge. After two years, the nubbins were collected and linear extension, density and calcification rates were analyzed. Preliminary results show that coral skeleton density is significantly lower in corals transplanted into the low pH than in corals transplanted in control sites. Infaunal bioerosion is present in corals deployed at low pH sites. In contrast, linear extension and hence calcification rates do not seem to show a significant difference among sites. However, the coral species show diverse calcification responses under ocean acidification conditions, suggesting some species may be more vulnerable than others to a change in water chemistry.

Identification of new 2,5-diketopiperazine derivatives as simultaneous effective inhibitors of αβ-tubulin and BCRP proteins: Molecular docking, Structure-Activity Relationships and virtual consensus docking studies

NASA Astrophysics Data System (ADS)

Fani, Najmeh; Sattarinezhad, Elham; Bordbar, Abdol-Khalegh

2017-06-01

In the first part of this paper, docking method was employed in order to study the binding mechanism of breast cancer resistance protein (BCRP) with a group of previously synthesized TPS-A derivatives which known as potent inhibitors of this protein to get insight into drug binding site of BCRP and to explore structure-activity relationship of these compounds. Molecular docking results showed that most of these compounds bind in the binding site of BCRP at the interface between the membrane and outer environment. In the second part, a group of designed TPS-A derivatives which showed good binding energies in the binding site of αβ-tubulin in the previous study were chosen to study their binding energies in the binding site of BCRP to investigate their simultaneous inhibitory effect on both αβ-tubulin and BCRP. The results showed that all of these compounds bind to the binding site of BCRP with relatively suitable binding energies and therefore could be potential inhibitors of both αβ-tubulin and BCRP proteins. Finally, virtual consensus docking method was utilized with the aim of design of new 2,5-diketopiperazine derivatives with significant inhibitory effect on both αβ-tubulin and BCRP proteins. For this purpose binding energies of a library of 2,5-diketopiperazine derivatives in the binding sites of αβ-tubulin and BCRP was investigated by using AutoDock and AutoDock vina tools. Molecular docking results revealed that a group of 36 compounds among them exhibit strong anti-tubulin and anti-BCRP activity.

Long-term trends in DDT, PCBs, and chlordane in mussels from California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stephenson, M.D.; Tjeerdema, R.S.

1994-12-31

Many contaminant programs have been established to study the geographical distributions and long-term trends of potential pollutants, but unfortunately, many have been short-lived because of economic cutbacks, providing limited information on long-term trends. The California State Mussel Watch program, however, has been continuously funded for the past 15 years. Several sites have been evaluated and were sampled often enough to obtain statistical resolution. Chlordane was evaluated at 29 stations, with 48% showing significant decreases over time; DDT was evaluated at 35 sites, with 43% showing significant declines; and PCBs were evaluated at 47 sites, with 21% showing significant drops overmore » time. Both DDT and PCBs showed declines, corresponding to decreases in their concentrations in the effluent, at sites located in the vicinity of the Los Angeles County municipal sewage outfall. This long-term investigation indicates that, contrary to public opinion, the banning of DDT, chlordane, and PCBs by the USEPA has led to overall improvement in water quality.« less

Extension of the Caucasus Seismic Information Network Study into Central Asia

DTIC Science & Technology

2008-09-01

nuclear tests at the Semipalatinsk test site in Kazakhstan, Lop Nor in China, Pokharan in India, and Chagai in Pakistan, as well as for several peaceful... Semipalatinsk test site in Kazakhstan, Lop Nor in China, Pokharan in India, and Chagai in Pakistan, and several peaceful nuclear explosion (PNE) events...truth in tomography studies. Figures 5 and 6 show waveforms for a nuclear explosion at the Semipalatinsk Test Site in northeast Kazakhstan and for a

The interaction of the Eco R1 restriction enzyme E.coli with nucleotides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hollis, Donald F.

1979-11-01

The Eco R1 restriction enzyme can be shown to be inhibited by nucleotides which correspond to any part of its known site of phosphodiesterase activity. A series of di-, tetra-, and hexa-nucleotide fragments were synthesized and their effect on the activity of the enzyme upon superhelical Co1 E1 DNA studied. The inhibition caused by the individual mononucleotides were also studied. In general all the nucleotide fragments showed some form of interaction with the enzyme system. Tetranucleotides were stronger inhibitors than dinucleotides, which in turn were stronger inhibitors than the mononucleotides. Within each category of inhibitors, those containing the phosphodiester bondmore » which is acted upon by the enzyme were the strongest inhibitors. Only those fragments which were consistent with the enzymes site of activity showed competitive inhibition kinetics. Nucleotides which do not fit within the site of phosphodiesterase activity show non-competitive inhibition kinetics.« less

On the behavior of site effects in central Mexico (the Mexican volcanic belt - MVB), based on records of shallow earthquakes that occurred in the zone between 1998 and 2011

NASA Astrophysics Data System (ADS)

Clemente-Chavez, A.; Zúñiga, F. R.; Lermo, J.; Figueroa-Soto, A.; Valdés, C.; Montiel, M.; Chavez, O.; Arroyo, M.

2014-06-01

The Mexican volcanic belt (MVB) is a seismogenic zone that transects the central part of Mexico with an east-west orientation. The seismic risk and hazard of this seismogenic zone has not been studied in detail due to the scarcity of instrumental data as well as because seismicity in the continental regime of central Mexico is not too frequent. However, it is known that there are precedents of large earthquakes (Mw > 6.0) that have taken place in this zone. The valley of Mexico City (VM) is the sole zone, within the MVB, that has been studied in detail. Studies have mainly focused on the ground amplification during large events such as the 1985 subduction earthquake that occurred off coast of Michoacán. The purpose of this article is to analyze the behavior of site effects in the MVB zone based on records of shallow earthquakes (data not reported before) that occurred in the zone between 1998 and 2011. We present a general overview of site effects in the MVB, a classification of the stations in order to reduce the uncertainty in the data when obtaining attenuation parameters in future works, as well as some comparisons between the information presented here and that presented in previous studies. A regional evaluation of site effects and Fourier acceleration spectrum (FAS) shape was estimated based on 80 records of 22 shallow earthquakes within the MVB zone. Data of 25 stations were analyzed. Site effects were estimated by using the horizontal-to-vertical spectral ratio (HVSR) methodology. The results show that seismic waves are less amplified in the northeast sites of the MVB with respect to the rest of the zone and that it is possible to classify two groups of stations: (1) stations with negligible site amplification (NSA) and (2) stations with significant site amplification (SSA). Most of the sites in the first group showed small (<3) amplifications while the second group showed amplifications ranging from 4 to 6.5 at frequencies of about 0.35, 0.75, 15 and 23 Hz. With these groups of stations, average levels of amplification were contrasted for the first time with those caused by the subduction zone earthquakes. With respect to the FAS shapes, most of them showed similarities at similar epicentral distances. Finally, some variations of site effects were found when compared to those obtained in previous studies on different seismicity regions. These variations were attributed to the location of the source. These aspects help to advance the understanding about the amplification behavior and of the expected seismic risk on central Mexico due to large earthquakes within the MVB seismogenic zone.

Visual event-related potential studies supporting the validity of VARK learning styles' visual and read/write learners.

PubMed

Thepsatitporn, Sarawin; Pichitpornchai, Chailerd

2016-06-01

The validity of learning styles needs supports of additional objective evidence. The identification of learning styles using subjective evidence from VARK questionnaires (where V is visual, A is auditory, R is read/write, and K is kinesthetic) combined with objective evidence from visual event-related potential (vERP) studies has never been investigated. It is questionable whether picture superiority effects exist in V learners and R learners. Thus, the present study aimed to investigate whether vERP could show the relationship between vERP components and VARK learning styles and to identify the existence of picture superiority effects in V learners and R learners. Thirty medical students (15 V learners and 15 R learners) performed recognition tasks with vERP and an intermediate-term memory (ITM) test. The results of within-group comparisons showed that pictures elicited larger P200 amplitudes than words at the occipital 2 site (P < 0.05) in V learners and at the occipital 1 and 2 sites (P < 0.05) in R learners. The between-groups comparison showed that P200 amplitudes elicited by pictures in V learners were larger than those of R learners at the parietal 4 site (P < 0.05). The ITM test result showed that a picture set showed distinctively more correct responses than that of a word set for both V learners (P < 0.001) and R learners (P < 0.01). In conclusion, the result indicated that the P200 amplitude at the parietal 4 site could be used to objectively distinguish V learners from R learners. A lateralization existed to the right brain (occipital 2 site) in V learners. The ITM test demonstrated the existence of picture superiority effects in both learners. The results revealed the first objective electrophysiological evidence partially supporting the validity of the subjective psychological VARK questionnaire study. Copyright © 2016 The American Physiological Society.

Interactive Visualization of Parking Orbits Around the Moon: An X3D Application for a NASA Lunar Mission Study

NASA Technical Reports Server (NTRS)

Murphy, Douglas G.; Qu, Min; Salas, Andrea O.

2006-01-01

The NASA Integrated Modeling and Simulation (IM&S) project aims to develop a collaborative engineering system to include distributed analysis, integrated tools, and web-enabled graphics. Engineers on the IM&S team were tasked with applying IM&S capabilities to an orbital mechanics analysis for a lunar mission study. An interactive lunar globe was created to show 7 landing sites, contour lines depicting the energy required to reach a given site, and the optimal lunar orbit orientation to meet the mission constraints. Activation of the lunar globe rotation shows the change of the angle between the landing site latitude and the orbit plane. A heads-up-display was used to embed straightforward interface elements.

In vitro and in vivo photosensitized inactivation of dermatophyte fungi by heterotricyclic dyes.

PubMed Central

Propst, C; Lubin, L

1978-01-01

The ability of three heterotricyclic dyes to photosensitize dermatophyte fungi was studied with Trichophyton mentagrophytes and Microsporum gypseum. In vitro studies showed that methylene blue, neutral red, and proflavine were capable of killing these fungi when used in conjunction with broad-spectrum light. Proflavine, however, killed both fungi most rapidly and was used for further studies. Fungal killing by proflavine plus light was dependent on dye concentration, pH, light wavelength, and light intensity. Based on the in vitro studies, a treatment regimen was developed for in vivo use on experimentally infected animals. When treatment of guinea pigs inoculated with T. mentagrophytes was begun during fungal invasion, lesion formation at inoculated sites was either prevented or substantially reduced. When treatment was begun after lesion formation, however, light-plus-dyed treated sites showed only slightly faster curing than untreated sites. PMID:669788

Chemostratigraphy at DSDP Sites 386 (Bermuda Rise) and 144 (Demerara Rise), Implications for Euxinic Conditions During OAE-2

NASA Astrophysics Data System (ADS)

Horst, P. A.; Maurrasse, F. J.; Sinninghe-Damsté, J. S.; Sandler, A.

2008-05-01

Chemostratigraphic studies of DSDP Site 386 on the Bermuda Rise and Site 144 on the Demerara Rise indicate that euxinic conditions developed at these deep-water sites during the time interval that corresponds to Oceanic Anoxic Event 2 (OAE 2). The data show a large increase in Fe/Al ratios, and dispersed pyrite aggregates (Site 386 Core 43, Section 3). Such findings at these deep oceanic sites are compatible with earlier studies showing that sediments in euxinic settings display increases in Fe/Al ratios due to the scavenging of dissolved Fe, and is also in agreement with previous Pr/Ph ratio of <1 (Simoneit, 1979). This study further shows that OM, previously believed to show bimodal distribution, which was used to argue in support of turbidity currents at Site 386 as transport mechanism for some of the OM, is predominantly derived from marine phytoplankton and cyanobacteria showing low thermal stress, supporting in situ derivation. Elemental analyses at Site 386 also show that relatively high Sr/CaO ratios are present before and after OAE 2, indicating an increased contribution of biogenic carbonates, but not during the C/T boundary event. When Cr is plotted against Al2O3 in conjunction with a solid line representing the Cr/Al2O3 ratio in average shale, half of the samples fall above and half fall below this line. The values that plot above this line are all from Cores 47, 44, 43, and 42, which contain higher TOC. Their strong Cr enrichment with respect to the average shale can be indicative of an algal source of the OM, as this biota preferentially concentrates Cr. Competitive exclusion due to dominance of opportunistic prokaryotic blooms in combination with oxygen depletion can be invoked to explain the conditions that developed and were unfavorable to most other organisms throughout the water column during OAE 2. Sediments from DSDP Site 144 also reveal increased molecular fossils indicative of green sulfur bacteria, which are further characteristic of euxinic conditions (Kuypers et al., 2002; Forster et al., 2004). These results are in agreement with earlier works that showed lipids at DSDP Site 144 are predominantly of an autochthonous origin with primary production as the dominant source (Simoneit and Stuermer, 1982). Biomarker data indicate that during OAE 2 similar paleoceanographic conditions prevailed at both DSDP Sites, 144 on the Demerara Rise and 386 on the Bermuda Rise. A. Forster, H. Sturt, P.A. Meyers, et al., in preliminary shipboard results from Sites 1257 and 1258, Leg 207, J. Erbacher, D.C. Mosher, M.J. Malone, et al., Proc. ODP, Init.Repts.207,1-22 [Online]: http://wwwodp.tamu.edu/publications/207_IR/VOLUME/ CHAPTERS/IR207_10.PDF. [Cited 2006-02-09] M.M.M. Kuypers, et al., Paleoceanography, 17, 4, 1051-1063 (2002) B.R.T. Simoneit, in Initial Reports of the Deep Sea Drilling Project, Vol. 43, Tucholke, B.E., Vogt, P.R., et al., 1979, Eds, Washington (U.S. Government Printing Office), pp. 643-650 (1979) B.R.T. Simoneit and D.H.Stuermer, in Cretaceous Oceans, S.O. Schlanger and M.B. Cita, Eds, Academic Press, New York, pp. 145-163 (1982)

Cultured allogeneic keratinocyte sheets accelerate healing compared to Op-site treatment of donor sites in burns.

PubMed

Duinslaeger, L A; Verbeken, G; Vanhalle, S; Vanderkelen, A

1997-01-01

Donor site treatment is a crucial issue in the treatment of extensive burns. In this single-blind, randomized study treatment of donor sites with a polyurethane dressing, Op-Site (Smith & Nephew, York, U.K.) is compared to treatment with allogeneic cultured keratinocyte sheets. Results show a mean healing time of 6.7 days with use of cultured keratinocyte sheets compared to mean healing time of 13.6 days with Op-Site treatment. Also, improvement in the comfort of patients as the result of less exudate formation and pain attenuation was noted.

Degradable poly(anhydride ester) implants: effects of localized salicylic acid release on bone.

PubMed

Erdmann, L; Macedo, B; Uhrich, K E

2000-12-01

Degradable poly(anhydride ester) implants in which the polymer backbone breaks down into salicylic acid (SA) were investigated. In this preliminary work, local release of SA from the poly(anhydride esters), thus classified as 'active polymers', on healthy bone and tissue was evaluated in vivo using a mouse model. Degradable polyanhydrides that break down into inactive by-products were used as control membranes because of their chemical similarity to the active polymers. Small polymer squares were inserted over the exposed palatal bone adjacent to the maxillary first molars. Active polymer membranes were placed on one side of the mouth, control polymers placed on the contra lateral side. Intraoral clinical examination showed that active polymer sites were less swollen and inflamed than control polymer sites. Histopathological examination at day 1 showed essentially no difference between control and active polymers. After 4 days, active polymer sites showed epithelial proliferation to a greater extent than the polyanhydride controls. After 20 days, active polymer sites showed greater thickness of new palatal bone and no resorptive areas, while control polymer sites showed less bone thickness as well as resorption including lacunae involving cementum and dentine. From these preliminary studies, we conclude that active polymers, namely poly(anhydride esters), stimulated new bone formation.

Site preference of alloying elements in DO22-Ni3V phase: Phase-field and first-principles study

NASA Astrophysics Data System (ADS)

Zhang, Ding-Ni; Shangguan, Qian-Qian; Liu, Fu; Zhang, Ming-Yi

2015-07-01

Site preference of alloying elements in DO22-Ni3V phase was investigated using phase-field and first-principles method. The concentrations of alloying elements on sublattices of DO22-Ni3V phase were quantitatively studied using phase-field model based on microscopic diffusion equations. The phase-field computation results demonstrate that the concentration differences of alloying elements on the NiI and NiII site are attributed to the coordination environment difference. Host atoms Ni and substitutional ternary additions Al prefer to occupy NiI site. Antisite atoms V show site preference on the NiII site. Further reason of site preference of alloying elements on the two different Ni sites were studied using first-principles method to calculate the electronic structure of DO22-Ni3V phase. Calculation of density of states, orbitals population and charge population of the optimized Ni3V structure found that the electronic structures of NiI and NiII sites are different. Electronic structure difference, which is caused by coordination environment difference, is the essential reason for site selectivity behaviors of alloying elements on NiI and NiII sites.

Intrinsic bioremediation of MTBE-contaminated groundwater at a petroleum-hydrocarbon spill site

NASA Astrophysics Data System (ADS)

Chen, K. F.; Kao, C. M.; Chen, T. Y.; Weng, C. H.; Tsai, C. T.

2006-06-01

An oil-refining plant site located in southern Taiwan has been identified as a petroleum-hydrocarbon [mainly methyl tert-butyl ether (MTBE) and benzene, toluene, ethylbenzene, and xylenes (BTEX)] spill site. In this study, groundwater samples collected from the site were analyzed to assess the occurrence of intrinsic MTBE biodegradation. Microcosm experiments were conducted to evaluate the feasibility of biodegrading MTBE by indigenous microorganisms under aerobic, cometabolic, iron reducing, and methanogenic conditions. Results from the field investigation and microbial enumeration indicate that the intrinsic biodegradation of MTBE and BTEX is occurring and causing the decrease in MTBE and BTEX concentrations. Microcosm results show that the indigenous microorganisms were able to biodegrade MTBE under aerobic conditions using MTBE as the sole primary substrate. The detected biodegradation byproduct, tri-butyl alcohol (TBA), can also be biodegraded by the indigenous microorganisms. In addition, microcosms with site groundwater as the medium solution show higher MTBE biodegradation rate. This indicates that the site groundwater might contain some trace minerals or organics, which could enhance the MTBE biodegradation. Results show that the addition of BTEX at low levels could also enhance the MTBE removal. No MTBE removal was detected in iron reducing and methanogenic microcosms. This might be due to the effects of low dissolved oxygen (approximately 0.3 mg/L) within the plume. The low iron reducers and methanogens (<1.8×103 cell/g of soil) observed in the aquifer also indicate that the iron reduction and methanogenesis are not the dominant biodegradation patterns in the contaminant plume. Results from the microcosm study reveal that preliminary laboratory study is required to determine the appropriate substrates and oxidation-reduction conditions to enhance the biodegradation of MTBE. Results suggest that in situ or on-site aerobic bioremediation using indigenous microorganisms would be a feasible technology to clean up this MTBE-contaminated site.

Reflex responses of lip muscles in young and older women.

PubMed

Wohlert, A B

1996-06-01

The perioral reflex in response to innocuous mechanical stimulation of the lip vermilion was studied in 20 young and 20 older women. Responses to stimuli at the right and left sides of both the upper and lower lips were recorded. Results show significant specificity of response, especially for upper lip sites. Reflex response at the site of stimulation was greatest in amplitude and shortest in latency, followed by response at sites ipsilateral to the site of stimulation. Younger subjects showed greater localizing tendency than older subjects. Stimulation was significantly less likely to produce a reflex response in the older group. When reflex responses did occur, they were significantly lower in amplitude and longer in latency than the responses of the younger group. Nonetheless, reflex responses were common in both groups, with responses at the site of stimulation occurring 78% of the time in older women and 90% of the time in younger women. Every participant showed at least one reflex response to lip stimulation. Results suggest decreasing complexity of synaptic drive to the perioral system in old age but also show that reflexive response does not deteriorate completely, remaining an available element for motor control in normal older women.

Impacts of off-road vehicles on nitrogen cycles in biological soil crusts: Resistance in different U.S. deserts

USGS Publications Warehouse

Belnap, Jayne

2002-01-01

Biological soil crusts are an important component of desert ecosystems, as they influence soil stability and fertility. This study examined and compared the short-term vehicular impacts on lichen cover and nitrogenase activity (NA) of biological soil crusts. Experimental disturbance was applied to different types of soil in regions throughout the western U.S. (Great Basin, Colorado Plateau, Sonoran, Chihuahuan, and Mojave deserts). Results show that pre-disturbance cover of soil lichens is significantly correlated with the silt content of soils, and negatively correlated with sand and clay. While disturbance appeared to reduce NA at all sites, differences were statistically significant at only 12 of the 26 sites. Cool desert sites showed a greater decline than hot desert sites, which may indicate non-heterocystic cyanobacterial species are more susceptible to disturbance than non-heterocystic species. Sandy soils showed greater reduction of NA as sand content increased, while fine-textured soils showed a greater decline as sand content increased. At all sites, higher NA before the disturbance resulted in less impact to NA post-disturbance. These results may be useful in predicting the impacts of off-road vehicles in different regions and different soils.

Interpreting large-scale experiments on effects of trawling on benthic fauna: an empirical test of the potential effects of spatial confounding in experiments without replicated control and trawled areas.

PubMed

Lindegarth; Valentinsson; Hansson; Ulmestrand

2000-03-15

Disturbances due to trawling and dredging is a serious threat to assemblages of benthic marine animals. We tested hypotheses about effects of trawling on benthic assemblages in a manipulative field experiment, using gear and intensities relevant to future management of trawling in a Swedish fjord. Three trawled and three control sites were sampled at several times before and after trawling was initiated. This paper describes how conclusions about effects of trawling might differ between experiments involving replicate sites and experiments using only one trawled and one control site, as in several recent studies. Analyses of selected taxa showed that abundances of many species changed differently among control sites. Differences in temporal change between pairs of single trawled and control sites were also frequent. Neither the quantitative nor the qualitative nature of differences between treatments could, however, be coherently interpreted among the different combinations of trawled and control sites. This is consistent with results obtained from analyses using all sites, which showed no consistent effects of trawling on any of these taxa. These results provide empirical evidence that spatial confounding may cause serious problems to formal interpretation of experiments, which use only one control and one trawled area. Such potential problems can best be solved by ensuring that the study incorporates more than one control site.

Evaluation of Streamflow Gain-Loss Characteristics of Hubbard Creek, in the Vicinity of a Mine-Permit Area, Delta County, Colorado, 2007

USGS Publications Warehouse

Ruddy, Barbara C.; Williams, Cory A.

2007-01-01

In 2007, the U.S. Geological Survey, in cooperation with Bowie Mining Company, initiated a study to characterize the streamflow and streamflow gain-loss in a reach of Hubbard Creek in Delta County, Colorado, in the vicinity of a mine-permit area planned for future coal mining. Premining streamflow characteristics and streamflow gain-loss variation were determined so that pre- and postmining gain-loss characteristics could be compared. This report describes the methods used in this study and the results of two streamflow-measurement sets collected during low-flow conditions. Streamflow gain-loss measurements were collected using rhodamine WT and sodium bromide tracers at four sites spanning the mine-permit area on June 26-28, 2007. Streamflows were estimated and compared between four measurement sites within three stream subreaches of the study reach. Data from two streamflow-gaging stations on Hubbard Creek upstream and downstream from the mine-permit area were evaluated. Streamflows at the stations were continuous, and flow at the upstream station nearly always exceeded the streamflow at the downstream station. Furthermore, streamflow at both stations showed similar diurnal patterns with traveltime offsets. On June 26, streamflow from the gain-loss measurements was greater at site 1 (most upstream site) than at site 4 (most downstream site); on June 27, streamflow was greater at site 4 than at site 2; and on June 27, there was no difference in streamflow between sites 2 and 3. Data from streamflow-gaging stations 09132940 and 09132960 showed diurnal variations and overall decreasing streamflow over time. The data indicate a dynamic system, and streamflow can increase or decrease depending on hydrologic conditions. The streamflow within the study reach was greater than the streamflows at either the upstream or downstream stations. A second set of gain-loss measurements was collected at sites 2 and 4 on November 8-9, 2007. On November 8, streamflow was greater at site 4 than at site 2, and on the following day, November 9, streamflow was greater at site 2 than at site 4. Data collection on November 8 occurred while the streamflow was increasing due to contributions from stream ice melting throughout different parts of the basin. Data collection on November 9 occurred earlier in the day with less stream ice melting and more steady-state conditions, so the indication that streamflow decreased between sites 2 and 4 may be more accurate. Diurnal variations in streamflow are common at both the upper and the lower streamflow-gaging stations. The upper streamflow-gaging station shows a melt-freeze influence from tributaries to Hubbard Creek during the winter season. Downstream from the study reach, observed diurnal variation is likely due to evapotranspiration associated with dense flood-plain vegetation, which consumes water from the creek during the middle of the day. Varying diurnal patterns in streamflow, combined with possible variations in tributary inflows to Hubbard Creek in the study reach, probably account for the observed variations in streamflow at the tracer measurement sites. During both sampling periods in June and November 2007, conditions were less than ideal and not steady state. The June 27 sampling indicates that the streamflow was increasing between measurement sites 2 and 4, and the November 9 sampling indicates that the streamflow was decreasing between measurement sites 2 and 4. The data collected during the diurnal and day-to-day variations in streamflow indicated that the streamflow reach is dynamic and can be gaining, losing, or constant.

Insight into the binding mechanism of imipenem to human serum albumin by spectroscopic and computational approaches.

PubMed

Rehman, Md Tabish; Shamsi, Hira; Khan, Asad U

2014-06-02

The mechanism of interaction between imipenem and HSA was investigated by various techniques like fluorescence, UV.vis absorbance, FRET, circular dichroism, urea denaturation, enzyme kinetics, ITC, and molecular docking. We found that imipenem binds to HSA at a high affinity site located in subdomain IIIA (Sudlow's site I) and a low affinity site located in subdomain IIA.IIB. Electrostatic interactions played a vital role along with hydrogen bonding and hydrophobic interactions in stabilizing the imipenem.HSA complex at subdomain IIIA, while only electrostatic and hydrophobic interactions were present at subdomain IIA.IIB. The binding and thermodynamic parameters obtained by ITC showed that the binding of imipenem to HSA was a spontaneous process (ΔGD⁰(D)= -32.31 kJ mol(-1) for high affinity site and ΔGD⁰(D) = -23.02 kJ mol(-1) for low affinity site) with binding constants in the range of 10(4)-10(5) M(-1). Spectroscopic investigation revealed only one binding site of imipenem on HSA (Ka∼10(4) M(-1)). FRET analysis showed that the binding distance between imipenem and HSA (Trp-214) was optimal (r = 4.32 nm) for quenching to occur. Decrease in esterase-like activity of HSA in the presence of imipenem showed that Arg-410 and Tyr-411 of subdomain IIIA (Sudlow's site II) were directly involved in the binding process. CD spectral analysis showed altered conformation of HSA upon imipenem binding. Moreover, the binding of imipenem to subdomain IIIA (Sudlow's site II) of HSA also affected its folding pathway as clear from urea-induced denaturation studies.

The effect of simultaneous substitution on the electronic band structure and thermoelectric properties of Se-doped Co3SnInS2 with the Kagome lattice

NASA Astrophysics Data System (ADS)

Fujioka, Masaya; Shibuya, Taizo; Nakai, Junya; Yoshiyasu, Keigo; Sakai, Yuki; Takano, Yoshihiko; Kamihara, Yoichi; Matoba, Masanori

2014-12-01

The thermoelectric properties and electronic band structures for Se-doped Co3SnInS2 were examined. The parent compound of this material (Co3Sn2S2) has two kinds of Sn sites (Sn1 and Sn2 sites). The density functional theory (DFT) calculations show that the indium substitution at the Sn2 site induces a metallic band structure, on the other hand, a semiconducting band structure is obtained from substitution at the Sn1 site. However, according to the previous reports, since the indium atom prefers to replace the tin atom at the Sn1 site rather than the Sn2 site, the resistivity of Co3SnInS2 shows semiconducting-like behavior. In this study we have demonstrated that metallic behavior and a decrease in resistivity for Se-doped Co3SnInS2 occurs without suppression of the Seebeck coefficient. From the DFT calculations, when the selenium content is above 0.5, the total crystallographic energy shows that a higher indium occupancy at Sn2 site is more stable. Therefore, it is suggested that the selenium doping suppress the site preference for indium substitution. This is one of the possible explanations for the metallic conductivity observed in Se-doped Co3SnInS2

Active sites of ligand-protected Au{sub 25} nanoparticle catalysts for CO{sub 2} electroreduction to CO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alfonso, Dominic R., E-mail: alfonso@netl.doe.gov; Kauffman, Douglas; Matranga, Christopher

2016-05-14

Recent experimental studies have reported the electrochemical reduction of carbon dioxide (CO{sub 2}) into CO at atomically precise negatively charged Au{sub 25}{sup −} nanoclusters. The studies showed CO{sub 2} conversion at remarkably low overpotentials, but the exact mechanisms and nature of the active sites remain unclear. We used first-principles density functional theory and continuum solvation models to examine the role of the cluster during electrochemical CO{sub 2} reduction and analyze the free energies of proposed intermediate species. Contrary to previous assumptions, our results show that the fully ligand protected cluster is not an active CO{sub 2} reduction catalyst because formationmore » of the crucial carboxyl intermediate required very high electrochemical potentials. Instead, our calculations suggest that the reduction process likely occurs on a dethiolated gold site, and adsorbed carboxyl intermediate formation was significantly stabilized at dethiolated gold sites. These findings point to the crucial role of exposed metal sites during electrochemical CO{sub 2} reduction at gold nanocluster catalysts.« less

The short-term effects of cisplatin chemotherapy on bone turnover.

PubMed

Young, D R; Virolainen, P; Inoue, N; Frassica, F J; Chao, E Y

1997-11-01

Cisplatin is an effective agent in the treatment of osteosarcoma of bone but little is known of its effects on normal bone turnover. Twenty-four dogs divided into three study groups were used to study the effect of cisplatin on normal bone turnover at the distant site of surgery. Group 1 served as the control group, group 2 received four cycles of cisplatin every 3 weeks before the surgery, and group 3 received four cycles postoperatively. The bone turnover rate was evaluated by measuring levels of systemic bone markers, osteocalcin, alkaline phospohatase, urine pyridinoline cross-links, and by determination histomorphometric indices. Histomorphological analysis showed poor correlation on bone formation with systemic bone markers at distant sites of surgery. Histomorphometrically normal bone turnover was affected by administration of cisplatin, but the effect was temporary, late, and less significant than what occurred at the surgical site. Our data showed that significant effects of cisplatin are observed at the site of active cellular induction and proliferation, such as implant-host interface, and less effects are seen at the sites of normal bone turnover.

Amyloid tracers detect multiple binding sites in Alzheimer's disease brain tissue.

PubMed

Ni, Ruiqing; Gillberg, Per-Göran; Bergfors, Assar; Marutle, Amelia; Nordberg, Agneta

2013-07-01

Imaging fibrillar amyloid-β deposition in the human brain in vivo by positron emission tomography has improved our understanding of the time course of amyloid-β pathology in Alzheimer's disease. The most widely used amyloid-β imaging tracer so far is (11)C-Pittsburgh compound B, a thioflavin derivative but other (11)C- and (18)F-labelled amyloid-β tracers have been studied in patients with Alzheimer's disease and cognitively normal control subjects. However, it has not yet been established whether different amyloid tracers bind to identical sites on amyloid-β fibrils, offering the same ability to detect the regional amyloid-β burden in the brains. In this study, we characterized (3)H-Pittsburgh compound B binding in autopsied brain regions from 23 patients with Alzheimer's disease and 20 control subjects (aged 50 to 88 years). The binding properties of the amyloid tracers FDDNP, AV-45, AV-1 and BF-227 were also compared with those of (3)H-Pittsburgh compound B in the frontal cortices of patients with Alzheimer's disease. Saturation binding studies revealed the presence of high- and low-affinity (3)H-Pittsburgh compound B binding sites in the frontal cortex (K(d1): 3.5 ± 1.6 nM; K(d2): 133 ± 30 nM) and hippocampus (K(d1):5.6 ± 2.2 nM; K(d2): 181 ± 132 nM) of Alzheimer's disease brains. The relative proportion of high-affinity to low-affinity sites was 6:1 in the frontal cortex and 3:1 in the hippocampus. One control showed both high- and low-affinity (3)H-Pittsburgh compound B binding sites (K(d1): 1.6 nM; K(d2): 330 nM) in the cortex while the others only had a low-affinity site (K(d2): 191 ± 70 nM). (3)H-Pittsburgh compound B binding in Alzheimer's disease brains was higher in the frontal and parietal cortices than in the caudate nucleus and hippocampus, and negligible in the cerebellum. Competitive binding studies with (3)H-Pittsburgh compound B in the frontal cortices of Alzheimer's disease brains revealed high- and low-affinity binding sites for BTA-1 (Ki: 0.2 nM, 70 nM), florbetapir (1.8 nM, 53 nM) and florbetaben (1.0 nM, 65 nM). BF-227 displaced 83% of (3)H-Pittsburgh compound B binding, mainly at a low-affinity site (311 nM), whereas FDDNP only partly displaced (40%). We propose a multiple binding site model for the amyloid tracers (binding sites 1, 2 and 3), where AV-45 (florbetapir), AV-1 (florbetaben), and Pittsburgh compound B, all show nanomolar affinity for the high-affinity site (binding site 1), as visualized by positron emission tomography. BF-227 shows mainly binding to site 3 and FDDNP shows only some binding to site 2. Different amyloid tracers may provide new insight into the pathophysiological mechanisms in the progression of Alzheimer's disease.

Multi-decadal analysis reveals contrasting patterns of resilience and decline in coral assemblages

NASA Astrophysics Data System (ADS)

Tanner, Jason E.

2017-12-01

A 50-yr study of coral dynamics at Heron Island, on Australia's Great Barrier Reef, shows that community change on a single reef is highly variable and that while some areas of the reef are in decline, others are recovering well 40 yr after a major cyclonic disturbance that eliminated all corals in the study plot. At one site, the genus-level composition in 2012 was identical to that before the cyclone, although it took around 30 yr to recover, and there were still differences at the species level. The colony size structure of some species at this site, notably the dominant Acropora digitifera, which had over 40% cover in 2012, also recovered after 30 yr, although sub-dominant species still lacked large colonies even after 40 yr. Given the small scale of the individual study plots (1 m2), this shows an unexpected degree of determinism in assemblage structure. At a second site, however, both composition and size structure changed dramatically over the last 40 yr of the study as both external and internal factors altered local environmental conditions. At both sites, major changes in composition appear to be related to drying out of the reef crest due to changes in flow regimes and/or natural accretion. At the site that has recovered, erosion has reversed this drying out, whereas no such erosion has occurred at the second site. If such erosion occurs, or sea levels increase due to global warming, then the second site may also prove to be resilient over decadal time scales.

Sequence-based model of gap gene regulatory network.

PubMed

Kozlov, Konstantin; Gursky, Vitaly; Kulakovskiy, Ivan; Samsonova, Maria

2014-01-01

The detailed analysis of transcriptional regulation is crucially important for understanding biological processes. The gap gene network in Drosophila attracts large interest among researches studying mechanisms of transcriptional regulation. It implements the most upstream regulatory layer of the segmentation gene network. The knowledge of molecular mechanisms involved in gap gene regulation is far less complete than that of genetics of the system. Mathematical modeling goes beyond insights gained by genetics and molecular approaches. It allows us to reconstruct wild-type gene expression patterns in silico, infer underlying regulatory mechanism and prove its sufficiency. We developed a new model that provides a dynamical description of gap gene regulatory systems, using detailed DNA-based information, as well as spatial transcription factor concentration data at varying time points. We showed that this model correctly reproduces gap gene expression patterns in wild type embryos and is able to predict gap expression patterns in Kr mutants and four reporter constructs. We used four-fold cross validation test and fitting to random dataset to validate the model and proof its sufficiency in data description. The identifiability analysis showed that most model parameters are well identifiable. We reconstructed the gap gene network topology and studied the impact of individual transcription factor binding sites on the model output. We measured this impact by calculating the site regulatory weight as a normalized difference between the residual sum of squares error for the set of all annotated sites and for the set with the site of interest excluded. The reconstructed topology of the gap gene network is in agreement with previous modeling results and data from literature. We showed that 1) the regulatory weights of transcription factor binding sites show very weak correlation with their PWM score; 2) sites with low regulatory weight are important for the model output; 3) functional important sites are not exclusively located in cis-regulatory elements, but are rather dispersed through regulatory region. It is of importance that some of the sites with high functional impact in hb, Kr and kni regulatory regions coincide with strong sites annotated and verified in Dnase I footprint assays.

Remote sensing for site characterization

USGS Publications Warehouse

Kuehn, Friedrich; King, Trude V.; Hoerig, Bernhard; Peters, Douglas C.; Kuehn, Friedrich; King, Trude V.; Hoerig, Bernhard; Peters, Douglas C.

2000-01-01

This volume, Remote Sensing for Site Characterization, describes the feasibility of aircraft- and satellite-based methods of revealing environmental-geological problems. A balanced ratio between explanations of the methodological/technical side and presentations of case studies is maintained. The comparison of case studies from North America and Germany show how the respective territorial conditions lead to distinct methodological approaches.

Green tea extract as a local drug therapy on periodontitis patients with diabetes mellitus: A randomized case-control study.

PubMed

Gadagi, Jayaprakash S; Chava, Vijay K; Reddy, Venkata Ramesh

2013-03-01

The green tea extract is a naturally occurring product having beneficial effects that counteract with the pathobiological features of periodontitis and diabetes mellitus. Hence, the present study was aimed at incorporation of green tea extract into hydroxylpropyl methylcellulose and investigates its efficacy in chronic periodontitis patients associated with and without diabetes mellitus. For the in vitro study, formulation of green tea strips and placebo strips, and analysis of drug release pattern from the green tea strips at different time intervals were performed. For the in vivo study, 50 patients (20-65 years), including 25 systemically healthy patients with chronic periodontitis (group 1) and 25 diabetic patients with chronic periodontitis (group 2) were enrolled. In each patient, test and control sites were identified for the placement of green tea and placebo strips, respectively. Gingival Index (GI), Probing Pocket Depth (PPD), and Clinical Attachment Level (CAL) were examined at baseline, first, second, third, and fourth weeks. Microbiological analysis for Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans was performed at baseline and fourth week. The in vitro study showed 10.67% green tea release at 30 min; thereafter, a slow release was noted till 120 min. Both groups showed significant reduction in GI scores at the test sites. Group 1 showed significant (P < 0.001) PPD reduction at different time intervals at the test sites. However, group 2 showed significant reduction from baseline (5.30 ± 0.70) to fourth week (3.5 ± 0.97). Statistically significant gain in CAL at the test sites was observed both in group 1 (1.33 mm) and group 2 (1.43 mm). The prevalence of P. gingivalis in group 1 test sites was significantly reduced from baseline (75%) to fourth week (25%). Local drug delivery using green tea extract could be used as an adjunct in the treatment of chronic periodontitis in diabetic and non-diabetic individuals.

Site-level progression of periodontal disease during a follow-up period

PubMed Central

Morozumi, Toshiya; Nakagawa, Taneaki; Sugaya, Tsutomu; Kawanami, Masamitsu; Suzuki, Fumihiko; Takahashi, Keiso; Abe, Yuzo; Sato, Soh; Makino-Oi, Asako; Saito, Atsushi; Takano, Satomi; Minabe, Masato; Nakayama, Yohei; Ogata, Yorimasa; Kobayashi, Hiroaki; Izumi, Yuichi; Sugano, Naoyuki; Ito, Koichi; Sekino, Satoshi; Numabe, Yukihiro; Fukaya, Chie; Yoshinari, Nobuo; Fukuda, Mitsuo; Noguchi, Toshihide; Kono, Tomoo; Umeda, Makoto; Fujise, Osamu; Nishimura, Fusanori; Yoshimura, Atsutoshi; Hara, Yoshitaka; Nakamura, Toshiaki; Noguchi, Kazuyuki; Kakuta, Erika; Hanada, Nobuhiro; Takashiba, Shogo; Amitani, Yasuharu; Yoshie, Hiromasa

2017-01-01

Periodontal disease is assessed and its progression is determined via observations on a site-by-site basis. Periodontal data are complex and structured in multiple levels; thus, applying a summary statistical approach (i.e., the mean) for site-level evaluations results in loss of information. Previous studies have shown the availability of mixed effects modeling. However, clinically beneficial information on the progression of periodontal disease during the follow-up period is not available. We conducted a multicenter prospective cohort study. Using mixed effects modeling, we analyzed 18,834 sites distributed on 3,139 teeth in 124 patients, and data were collected 5 times over a 24-month follow-up period. The change in the clinical attachment level (CAL) was used as the outcome variable. The CAL at baseline was an important determinant of the CAL changes, which varied widely according to the tooth surface. The salivary levels of periodontal pathogens, such as Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, were affected by CAL progression. “Linear”- and “burst”-type patterns of CAL progression occurred simultaneously within the same patient. More than half of the teeth that presented burst-type progression sites also presented linear-type progression sites, and most of the progressions were of the linear type. Maxillary premolars and anterior teeth tended to show burst-type progression. The parameters identified in this study may guide practitioners in determining the type and extent of treatment needed at the site and patient levels. In addition, these results show that prior hypotheses concerning "burst" and "linear" theories are not valid. PMID:29206238

Relation between physico-chemical limnology and crustacean community in Wular Lake of Kashmir Himalaya.

PubMed

Shah, Javaid Ahmad; Pandit, Ashok K

2013-10-01

The present study scrutinizes the seasonal variation in the distribution of crustacean zooplankton in relation to physico-chemical liminology of Wular lake. Water samples were collected from five study sites during September 2010-August 2011. Remarkable spatial and temporal variations were observed among the different study sites. Among the parameters recorded water temperature showed positive correlation with pH (p<0.01) and orthophosphate (p<0.05).Transparency showed a significant negative correlation with total alkalinity (p<0.01), free carbon dioxide (p<0.01) and ammonical nitrogen (p<0.01). Crustacean zooplankton were collected by filtering 100 L lake water through a 30 microm nytal mesh and preserved in 4% formalin. A total of 42 taxa of crustacean were recorded, among them 23 species belonged to Cladocera, 16 to Copepoda and only 3 to Ostracoda. Species diversity and density depicted an abrupt up surge on the advent of warmer period (extending from March). Among the various sites a maximum of 40 species were recorded from a single biotope (site III) against the minimum of only 17 species being recorded from site I. Bray-Curtis cluster analysis showed close similarity (0.928-0.944%) between summer and autumn in terms of species diversity. Pearson correlation coefficient of the various physico-chemical parameters of water with crustacean zooplankton depicted that not only a single but multiple factors govern over the distribution and diversity of crustacean in the lake.

[Local reactions after diphtheria-tetanus-acellular pertussis vaccines in mice; changes in histopathology at the injection site].

PubMed

Nagaoka, Chiharu; Katsuta, Tomohiro; Honjo, Ayako; Tateyama, Satoshi; Tokutake, Tadaomi; Arimoto, Yutaka; Nakajima, Natsuki; Goshima, Toshiro; Kato, Tatsuo

2006-03-01

Diphtheria-tetanus-acellular pertussis vaccine (DTaP) developed in Japan is now widely used worldwide. DTaP is safer than the diphtheria-tetanus-whole-cell pertussis vaccine (DTwP) and has fewer severe side effects, but local reactions such as redness, swelling, and induration are still reported. The pathophysiological mechanism of these reactions is controversial. To clarify the cause of local reactions, we conducted studies using the mouse model. After administering either one or two abdominal subcutaneous DTaP inoculations, we observed changes in histopathology at the injection site at 24h, 48h, and 7 days. The control group, inoculated with physiologic saline, showed no significant changes either pathologically or with the naked eye. All mice after DTaP vaccination showed indurations at the injection site. Pathologically, we watched leukocyte invasion into or around the site, especially neutrophils and eosinophils. After the first vaccination, the extent of the invasion was strong 24h and 7 days later. At 24h following the second vaccination, a dramatic leukocyte invasion seen persisted at 7days. At 7 days after the first vaccination, peripheral fibrosis had begun, and when a second vaccination was administered, it began even earlier at the second site. These histopathological changes show that local reactions are caused by both inflammatory and allergic responses. Because this mouse study resulted in the same pattern of reactions observed in humans, this method will be useful for studies focusing on local reactions.

Nutrient and suspended-sediment trends, loads, and yields and development of an indicator of streamwater quality at nontidal sites in the Chesapeake Bay watershed, 1985-2010

USGS Publications Warehouse

Langland, Michael; Blomquist, Joel; Moyer, Douglas; Hyer, Kenneth

2012-01-01

The U.S. Geological Survey (USGS) updates information on loads of, and trends in, nutrients and sediment annually to help the Chesapeake Bay Program (CBP) investigators assess progress toward improving water-quality conditions in the Chesapeake Bay and its watershed. CBP scientists and managers have worked since 1983 to improve water quality in the bay. In 2010, the U.S. Environmental Protection Agency (USEPA) established a Total Maximum Daily Load (TMDL) for the Chesapeake Bay. The TMDL specifies nutrient and sediment load allocations that need to be achieved in the watershed to improve dissolved oxygen, water-clarity, and chlorophyll conditions in the bay. The USEPA, USGS, and state and local jurisdictions in the watershed operate a CBP nontidal water-quality monitoring network and associated database that are used to update load and trend information to help assess progress toward reducing nutrient and sediment inputs to the bay. Data collected from the CBP nontidal network were used to estimate loads and trends for two time periods: a long-term period (1985-2010) at 31 "primary" sites (with storm sampling) and a 10-year period (2001-10) at 33 primary sites and 16 "secondary" sites (without storm sampling). In addition, loads at 64 primary sites were estimated for the period 2006 to 2010. Results indicate improving flow-adjusted trends for nitrogen and phosphorus for 1985 to 2010 at most of the sites in the network. For nitrogen, 21 of the 31 sites showed downward (improving) trends, whereas 2 sites showed upward (degrading) trends, and 8 sites showed no trends. The results for phosphorus were similar: 22 sites showed improving trends, 4 sites showed degrading trends, and 5 sites indicated no trends. For sediment, no trend was found at 40 percent of the sites, with 10 sites showing improving trends and 8 sites showing degrading trends. The USGS, working with CBP partners, developed a new water-quality indicator that combines the results of the 10-year trend analysis with results from a greater number of sites (64 primary sites) where loads and yields of total nitrogen and phosphorus and sediment could be calculated. The new indicator shows fewer significant trends for the 10-year time period than for the long-term time period (1985-2010). For 2001-10, total nitrogen trends were downward (improving) at 14 sites and upward (degrading) at 2 sites; no trend was found at 17 sites. For total phosphorus, 12 sites showed improving trends, 4 sites showed degrading trends, and 17 sites showed no trend. For total sediment, most sites (21) did not exhibit a significant trend; 3 sites showed improving trends, and 10 sites showed degrading trends. Few significant trends were seen at the 16 secondary sites: improving trends for total nitrogen at 4 sites, improving trends for total phosphorus at 2 sites, and a degrading trend for sediment at 1 site. Total streamflow to the Chesapeake Bay was 20 percent higher in 2010 than in 2009 and is considered to be within the normal range of flow, whereas annual streamflow at 28 sites was greater in 2010 than in 2009. No trends in daily streamflow were detected at the 31 long-term sites. Combined loads for the farthest downstream nontidal monitoring sites (called "River Input Monitoring sites") increased 33 percent for total nitrogen, 120 percent for total phosphorus, and 330 percent for total sediment from 2009 to 2010. The large increase in phosphorus and sediment loads in 2010 was caused in large part by two large storm events that occurred during the spring in the Potomac River Basin. Yields (load per watershed area) of total nitrogen in the Chesapeake Bay watershed decreased from north to south (New York to Virginia). No spatial patterns were discernible for total phosphorus or sediment.

Assessment of trace metals using lichen transplant from automobile mechanic workshop in Ile-Ife metropolis, Nigeria.

PubMed

Odiwe, Anthony I; Adesanwo, Adeyemi T J; Olowoyo, Joshua O; Raimi, Idris O

2014-04-01

The level of air pollution around the automobile mechanic workshops has been generally overlooked. This study, examined the level of trace metals in automobile mechanic workshops and the suitability of using transplanted lichen thalli of Lepraria incana for measuring air pollution in such areas. Samples of the lichen thalli were transplanted into seven different sites and were attached to the bark of trees at each site. The samples were harvested from the sites after 3-month exposure. Concentrations of Pb, Cu, Cd, Fe, Zn, and S content were determined using an atomic absorption spectrophotometer. Results showed that there was a significant difference in the trace metals concentrations across the sites (p < 0.05). The analyzed lichen samples showed a range of 91.26-119.35 ppm for Fe, 30.23-61.32 ppm for Zn, 1.25-2.45 ppm for Cu, 0.017-0.043 ppm for Cd, 0.018-0.051 ppm, and 0.37-0.42 ppm for S. From the study, sites 6 and 7 presented higher concentrations of Cd, Pb, and Zn than other sites. The enrichment factor calculated showed that Zn, Cd, and Pb were greatly enriched from the workshops. The trend in the concentration of these heavy metals suggests that activities in these workshops might become a major source of certain heavy metals in the environment and if the pollution activities persist, it might become worrisome over time.

Structural evolution of luciferase activity in Zophobas mealworm AMP/CoA-ligase (protoluciferase) through site-directed mutagenesis of the luciferin binding site.

PubMed

Prado, R A; Barbosa, J A; Ohmiya, Y; Viviani, V R

2011-07-01

The structural origin and evolution of bioluminescent activity of beetle luciferases from AMP/CoA ligases remains a mystery. Previously we cloned the luciferase-like enzyme from Zophobas morio mealworm, a reasonable protoluciferase model that could shine light on this mystery. Kinetic characterization and studies with D- and L-luciferin and their adenylates showed that stereoselectivity constitutes a critical feature for the origin of luciferase activity in AMP/CoA ligases. Comparison of the primary structures and modeling studies of this protoluciferase and the three main families of beetle luciferases showed that the carboxylic acid substrate binding site of this enzyme is smaller and more hydrophobic than the luciferin binding site of beetle luciferases, showing several substitutions of otherwise conserved residues. Thus, here we performed a site-directed mutagenesis survey of the carboxylic binding site motifs of the protoluciferase by replacing their residues by the respective conserved ones found in beetle luciferases in order to identify the structural determinants of luciferase/oxygenase activity. Although most of the substitutions had negative impact on the luminescence activity of the protoluciferase, only the substitution I327T improved the luminescence activity, resulting in a broad and 15 nm blue-shifted luminescence spectrum. Such substitution indicates the importance of the loop motif 322YGMSEI327 (341YGLTETT347 in Photinus pyralis luciferase) for luciferase activity, and indicates a possible route for the evolution of bioluminescence function of beetle luciferases.

Assessments of Wind-Energy Potential in Selected Sites from Three Geopolitical Zones in Nigeria: Implications for Renewable/Sustainable Rural Electrification

PubMed Central

Okeniyi, Joshua Olusegun; Ohunakin, Olayinka Soledayo; Okeniyi, Elizabeth Toyin

2015-01-01

Electricity generation in rural communities is an acute problem militating against socioeconomic well-being of the populace in these communities in developing countries, including Nigeria. In this paper, assessments of wind-energy potential in selected sites from three major geopolitical zones of Nigeria were investigated. For this, daily wind-speed data from Katsina in northern, Warri in southwestern and Calabar in southeastern Nigeria were analysed using the Gumbel and the Weibull probability distributions for assessing wind-energy potential as a renewable/sustainable solution for the country's rural-electrification problems. Results showed that the wind-speed models identified Katsina with higher wind-speed class than both Warri and Calabar that were otherwise identified as low wind-speed sites. However, econometrics of electricity power simulation at different hub heights of low wind-speed turbine systems showed that the cost of electric-power generation in the three study sites was converging to affordable cost per kWh of electric energy from the wind resource at each site. These power simulations identified cost/kWh of electricity generation at Kaduna as €0.0507, at Warri as €0.0774, and at Calabar as €0.0819. These bare positive implications on renewable/sustainable rural electrification in the study sites even as requisite options for promoting utilization of this viable wind-resource energy in the remote communities in the environs of the study sites were suggested. PMID:25879063

Assessments of wind-energy potential in selected sites from three geopolitical zones in Nigeria: implications for renewable/sustainable rural electrification.

PubMed

Okeniyi, Joshua Olusegun; Ohunakin, Olayinka Soledayo; Okeniyi, Elizabeth Toyin

2015-01-01

Electricity generation in rural communities is an acute problem militating against socioeconomic well-being of the populace in these communities in developing countries, including Nigeria. In this paper, assessments of wind-energy potential in selected sites from three major geopolitical zones of Nigeria were investigated. For this, daily wind-speed data from Katsina in northern, Warri in southwestern and Calabar in southeastern Nigeria were analysed using the Gumbel and the Weibull probability distributions for assessing wind-energy potential as a renewable/sustainable solution for the country's rural-electrification problems. Results showed that the wind-speed models identified Katsina with higher wind-speed class than both Warri and Calabar that were otherwise identified as low wind-speed sites. However, econometrics of electricity power simulation at different hub heights of low wind-speed turbine systems showed that the cost of electric-power generation in the three study sites was converging to affordable cost per kWh of electric energy from the wind resource at each site. These power simulations identified cost/kWh of electricity generation at Kaduna as €0.0507, at Warri as €0.0774, and at Calabar as €0.0819. These bare positive implications on renewable/sustainable rural electrification in the study sites even as requisite options for promoting utilization of this viable wind-resource energy in the remote communities in the environs of the study sites were suggested.

An example of aerosol pattern variability over bright surface using high resolution MODIS MAIAC: The eastern and western areas of the Dead Sea and environs.

PubMed

Lee, Sever; Pinhas, Alpert; Alexei, Lyapustin; Yujie, Wang; Alexandra, Chudnovsky A

2017-09-01

The extreme rate of evaporation of the Dead Sea (DS) has serious implicatios for the surrounding area, including atmospheric conditions. This study analyzes the aerosol properties over the western and eastern parts of the DS during the year 2013, using MAIAC (Multi-Angle Implementation of Atmospheric Correction) for MODIS, which retrieves aerosol optical depth (AOD) data at a resolution of 1km. The main goal of the study is to evaluate MAIAC over the study area and determine, for the first time, the prevailing aerosol spatial patterns. First, the MAIAC-derived AOD data was compared with data from three nearby AERONET sites (Nes Ziona - an urban site, and Sede Boker and Masada - two arid sites), and with the conventional Dark Target (DT) and Deep Blue (DB) retrievals for the same days and locations, on a monthly basis throughout 2013. For the urban site, the correlation coefficient (r) for DT/DB products showed better performance than MAIAC (r=0.80, 0.75, and 0.64 respectively) year-round. However, in the arid zones, MAIAC showed better correspondence to AERONET sites than the conventional retrievals (r=0.58-0.60 and 0.48-0.50 respectively). We investigated the difference in AOD levels, and its variability, between the Dead Sea coasts on a seasonal basis and calculated monthly/seasonal AOD averages for presenting AOD patterns over arid zones. Thus, we demonstrated that aerosol concentrations show a strong preference for the western coast, particularly during the summer season. This preference, is most likely a result of local anthropogenic emissions combined with the typical seasonal synoptic conditions, the Mediterranean Sea breeze, and the region complex topography. Our results also indicate that a large industrial zone showed higher AOD levels compared to an adjacent reference-site, i.e., 13% during the winter season.

Landfill Site Selection by AHP Based Multi-criteria Decision Making Tool: A Case Study in Kolkata, India

NASA Astrophysics Data System (ADS)

Majumdar, Ankush; Hazra, Tumpa; Dutta, Amit

2017-09-01

This work presents a Multi-criteria Decision Making (MCDM) tool to select a landfill site from three candidate sites proposed for Kolkata Municipal Corporation (KMC) area that complies with accessibility, receptor, environment, public acceptability, geological and economic criteria. Analytical Hierarchy Process has been used to solve the MCDM problem. Suitability of the three sites (viz. Natagachi, Gangajoara and Kharamba) as landfills as proposed by KMC has been checked by Landfill Site Sensitivity Index (LSSI) as well as Economic Viability Index (EVI). Land area availability for disposing huge quantity of Municipal Solid Waste for the design period has been checked. Analysis of the studied sites show that they are moderately suitable for landfill facility construction as both LSSI and EVI scores lay between 300 and 750. The proposed approach represents an effective MCDM tool for siting sanitary landfill in growing metropolitan cities of developing countries like India.

How the Website Usability Elements Impact Performance

NASA Astrophysics Data System (ADS)

Aljukhadar, Muhammad; Senecal, Sylvain

This research builds on the results of a large scale study in which participants performed an informational task on one of 59 websites spanning various industries to examine how the website usability elements (graphical attractiveness, information, interactivity, trust, and ease of use) drive users’ attitudes and intentions toward the website and how these effects vary according to site experience and end product tangibility. Results show that while the effects of site interactivity and graphical attractiveness were more influential for services sites, the effects of site information and trust were stronger for tangibles sites. Alternatively, compared to returning site visitors, first-time visitors perceived the website as less easy to use, needed more time to accomplish the online task, and based positive attitudes and intentions more strongly on the site information and interactivity. The results of a second study performed in a proximate culture largely corroborate these findings.

Quantifying cambial activity of high-elevation conifers in the Great Basin, Nevada, USA

NASA Astrophysics Data System (ADS)

Ziaco, E.; Biondi, F.; Rossi, S.; Deslauriers, A.

2013-12-01

Understanding the physiological mechanisms that control the formation of tree rings provides the necessary biological basis for developing dendroclimatic reconstructions and dendroecological histories. Studies of wood formation in the Great Basin are now being conducted in connection with the Nevada Climate-ecohydrological Assessment Network (NevCAN), a recently established transect of valley-to-mountaintop instrumented stations in the Snake and Sheep Ranges of the Great Basin. Automated sensors record meteorological, soil, and vegetational variables at these sites, providing unique opportunities for ecosystem science, and are being used to investigate the ecological implications of xylogenesis. We present here an initial study based on microcores collected during summer 2013 from mountain and subalpine conifers (including Great Basin bristlecone pine, Pinus longaeva) growing on the west slope of Mt. Washington. Samples were taken from the mountain west (SM; 2810 m elevation) and the subalpine west (SS, 3355 m elevation) NevCAN sites on June 16th and 27th, 2013. The SS site was further subdivided in a high (SSH) and a low (SSL) group of trees, separated by about 10 m in elevation. Microscopic analyses showed the effect of elevation on cambial activity, as annual ring formation was more advanced at the lower (mountain) site compared to the higher (subalpine) one. At all sites cambium size showed little variations between the two sampling dates. The number of xylem cells in the radial enlargement phase decreased between the two sampling dates at the mountain site but increased at the subalpine site, confirming a delayed formation of wood at the higher elevations. Despite relatively high within-site variability, a general trend of increasing number of cells in the lignification phase was found at all sites. Mature cells were present only at the mountain site on June 27th. Spatial differences in the xylem formation process emerged at the species level and, within species, at different locations. In particular, bristlecone pines growing at SSL showed slightly more advanced tree-ring formation compared to those growing at SSH. These results highlight differences in xylogenesis related to elevation, a clear proxy for climate in this region, and further analyses will focus on understanding the climatic factors that drive wood formation in Great Basin conifers. Fig.1 Boxplot summary of cell types found at the study sites during two sampling dates.

On the behavior of site effects in Central Mexico (the Mexican Volcanic Belt - MVB), based on records of shallow earthquakes that occurred in the zone between 1998 and 2011

NASA Astrophysics Data System (ADS)

Clemente-Chavez, A.; Zúñiga, F. R.; Lermo, J.; Figueroa-Soto, A.; Valdés, C.; Montiel, M.; Chavez, O.; Arroyo, M.

2013-11-01

The Mexican Volcanic Belt (MVB) is a seismogenic zone that transects the central part of Mexico with an east-west orientation. The risk and hazard seismic of this seismogenic zone has not been studied at detail due to the scarcity of instrumental data as well as because seismicity in the continental regimen of Central Mexico is not too frequent, however, it is known that there are precedents of large earthquakes (Mw > 6.0) that have taken place in this zone. The Valley of Mexico City (VM) is the sole zone, within the MVB, which has been studied in detail; mainly focusing on the ground amplification during large events such as the 1985 subduction earthquake that occurred in Michoacan. The purpose of this article is to analyze the behavior of site effects in the MVB zone based on records of shallow earthquakes (data not reported before) that occurred in the zone between 1998 and 2011. We present a general overview of site effects on the MVB, a classification of the stations in order to reduce the uncertainty in the data to obtain attenuation parameters in future works, and some comparisons between the information presented here and that presented in previous studies. A regional evaluation of site effects and Fourier Acceleration Spectrum (FAS) shape was estimated based on 80 records of 22 shallow earthquakes within the MVB zone. Data of 25 stations were analyzed. Site effects were estimated by using the Horizontal-to-Vertical Spectral Ratio (HVSR) methodology. The results show that seismic waves are less amplified in the northeast sites of the MVB with respect to the rest of the zone and that it is possible to classify two groups of stations: (1) stations with Negligible Site Amplification (NSA) and (2) stations with Significant Site Amplification (SSA). Most of the sites in the first group showed small (< 3) amplifications while the second group showed amplifications ranging from 4 to 6.5 at frequencies of about 0.35, 0.75, 15 and 23 Hz. With these groups of stations, average levels of amplification were contrasted for the first time with those caused by the subduction zone earthaquakes. With respect to the FAS shapes, most of them showed similarities at similar epicentral distances. Finally, some variations of site effects were found when compared to those obtained in previous studies on different seismicity regions. These variations were attributed to the location of the source. These aspects help to advance the understanding about the amplification behavior and of the expected seismic risk on the Central Mexico due to large earthquakes within the MVB seismogenic zone.

Allosteric site-mediated active site inhibition of PBP2a using Quercetin 3-O-rutinoside and its combination.

PubMed

Rani, Nidhi; Vijayakumar, Saravanan; P T V, Lakshmi; Arunachalam, Annamalai

2016-08-01

Recent crystallographic study revealed the involvement of allosteric site in active site inhibition of penicillin binding protein (PBP2a), where one molecule of Ceftaroline (Cef) binds to the allosteric site of PBP2a and paved way for the other molecule (Cef) to bind at the active site. Though Cef has the potency to inhibit the PBP2a, its adverse side effects are of major concern. Previous studies have reported the antibacterial property of Quercetin derivatives, a group of natural compounds. Hence, the present study aims to evaluate the effect of Quercetin 3-o-rutinoside (Rut) in allosteric site-mediated active site inhibition of PBP2a. The molecular docking studies between allosteric site and ligands (Rut, Que, and Cef) revealed a better binding efficiency (G-score) of Rut (-7.790318) and Cef (-6.194946) with respect to Que (-5.079284). Molecular dynamic (MD) simulation studies showed significant changes at the active site in the presence of ligands (Rut and Cef) at allosteric site. Four different combinations of Rut and Cef were docked and their G-scores ranged between -6.320 and -8.623. MD studies revealed the stability of the key residue (Ser403) with Rut being at both sites, compared to other complexes. Morphological analysis through electron microscopy confirmed that combination of Rut and Cefixime was able to disturb the bacterial cell membrane in a similar fashion to that of Rut and Cefixime alone. The results of this study indicate that the affinity of Rut at both sites were equally good, with further validations Rut could be considered as an alternative for inhibiting MRSA growth.

Study on detecting leachate leakage of municipal solid waste landfill site.

PubMed

Liu, Jiangang; Cao, Xianxian; Ai, Yingbo; Zhou, Dongdong; Han, Qiting

2015-06-01

The article studies the detection of the leakage passage of leachate in a waste landfill dam. The leachate of waste landfill has its own features, like high conductivity, high chroma and an increasing temperature, also, the horizontal flow velocity of groundwater on the leakage site increases. This article proposes a comprehensive tracing method to identify the leakage site of an impermeable membrane by using these features. This method has been applied to determine two leakage sites of the Yahu municipal solid waste landfill site in Pingshan District, Shenzhen, China, which shows that there are two leachate leakage passages in the waste landfill dam A between NZK-2 and NZK-3, and between NZK-6 and NZK-7. © The Author(s) 2015.

A simple and efficient method for predicting protein-protein interaction sites.

PubMed

Higa, R H; Tozzi, C L

2008-09-23

Computational methods for predicting protein-protein interaction sites based on structural data are characterized by an accuracy between 70 and 80%. Some experimental studies indicate that only a fraction of the residues, forming clusters in the center of the interaction site, are energetically important for binding. In addition, the analysis of amino acid composition has shown that residues located in the center of the interaction site can be better discriminated from the residues in other parts of the protein surface. In the present study, we implement a simple method to predict interaction site residues exploiting this fact and show that it achieves a very competitive performance compared to other methods using the same dataset and criteria for performance evaluation (success rate of 82.1%).

Facebook as a Learning Tool? A Case Study on the Appropriation of Social Network Sites from Mobile Phones in Developing Countries

ERIC Educational Resources Information Center

Pimmer, Christoph; Linxen, Sebastian; Grohbiel, Urs

2012-01-01

This exploratory research investigates how students and professionals use social network sites (SNSs) in the setting of developing and emerging countries. Data collection included focus groups consisting of medical students and faculty as well as the analysis of a Facebook site centred on medical and clinical topics. The findings show how users,…

The use of biotic and abiotic components of Red Sea coastal areas as indicators of ecosystem health.

PubMed

Omar, Wael A; Saleh, Yousef S; Marie, Mohamed-Assem S

2016-03-01

A biomonitoring study was conducted using some biotic (Pomadasys hasta and Lutjanus russellii fish) and abiotic (water and sediment) components of the Red Sea coast of Hodeida, Yemen Republic along two polluted sites (Al-Dawar beach and Urj village) in comparison to a reference site (Al-Nukhailah beach). The studied fish biomarkers included hepatosomatic index (HSI), condition factor (K), scaled mass index (SMI), catalase, glutathione-S-transferase (GST), malondialdehyde (MDA), total protein and albumin. In addition, metals (Fe, Cu, Zn, Pb and Cd) concentrations in water and sediment were measured and sediment pollution assessment was carried out using contamination factor (CF), geoaccumulation index (Igeo), pollution load index (PLI) and enrichment factor (EF). The studied metals concentration in water and sediment samples showed significant increase among the polluted sites in comparison to the reference site. Sediment pollution assessment generally confirmed that Urj village was the most contaminated site followed by Al-Dawar beach. Catalase, GST and MDA proved to be the most responsive biomarkers with increased values of GST and MDA at sites influenced by agricultural, urban and industrial activities while catalase, HSI, K, SMI, total protein and albumin showed the opposite trend. This study recommends monitoring of sediment Igeo and EF values as well as SMI, catalase, GST and MDA as sensitive indicators of different anthropogenic activities and their effects on aquatic ecosystems under complex and different gradients of metal pollution. In addition, P. hasta proved to be more sensitive towards the detected pollution condition.

Prevention of railway trespassing by automatic sound warning-A pilot study.

PubMed

Kallberg, Veli-Pekka; Silla, Anne

2017-04-03

The objective of this study was to investigate the effects of a sound warning system on the frequency of trespassing at 2 pilot test sites in Finland. The effect of automatic prerecorded sound warning on the prevention of railway trespassing was evaluated based on observations at 2 test sites in Finland. At both sites an illegal footpath crossed the railway, and the average daily number of trespassers before implementation of the measures was about 18 at both sites. The results showed that trespassing was reduced at these sites by 18 and 44%, respectively. Because of the lack of proper control sites, it is possible that the real effects of the measure are somewhat smaller. The current study concludes that automatic sound warning may be efficient and cost effective at locations where fencing is not a viable option. However, it is not likely to be a cost-effective panacea for all kinds of sites where trespassing occurs, especially in countries like Finland where trespassing is scattered along the railway network rather than concentrated to a limited number of sites.

The effect of types of banner ad, Web localization, and customer involvement on Internet users' attitudes.

PubMed

Chen, Jengchung Victor; Ross, William H; Yen, David C; Akhapon, Lerdsuwankij

2009-02-01

In this study, three characteristics of Web sites were varied: types of banner ad, Web localization, and involvement in purchasing a product. The dependent variable was attitude toward the site. In laboratory experiments conducted in Thailand and Taiwan, participants browsed versions of a Web site containing different types of banner ads and products. As a within-participants factor, each participant browsed both a standardized English-language Web site and a localized Web site. Results showed that animated (rather than static) banner ads, localized versions (rather than a standardized version) of Web sites, and high (rather than low) product involvement led to favorable attitudes toward the site.

Neurobehavioral effects of arsenic exposure among secondary school children in the Kandal Province, Cambodia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vibol, Sao; Faculty of Agricultural Technology and Management, Royal University of Agriculture, Phnom Penh; Hashim, Jamal Hisham, E-mail: jamalhas@hotmail.com

The research was carried out at 3 study sites with varying groundwater arsenic (As) levels in the Kandal Province of Cambodia. Kampong Kong Commune was chosen as a highly contaminated site (300–500 μg/L), Svay Romiet Commune was chosen as a moderately contaminated site (50–300 μg/L) and Anlong Romiet Commune was chosen as a control site. Neurobehavioral tests on the 3 exposure groups were conducted using a modified WHO neurobehavioral core test battery. Seven neurobehavioral tests including digit symbol, digit span, Santa Ana manual dexterity, Benton visual retention, pursuit aiming, trail making and simple reaction time were applied. Children's hair samplesmore » were also collected to investigate the influence of hair As levels on the neurobehavioral test scores. The results from the inductively coupled plasma-mass spectrometry (ICP-MS) analyses of hair samples showed that hair As levels at the 3 study sites were significantly different (p<0.001), whereby hair samples from the highly contaminated site (n=157) had a median hair As level of 0.93 μg/g, while the moderately contaminated site (n=151) had a median hair As level of 0.22 μg/g, and the control site (n=214) had a median hair As level of 0.08 μg/g. There were significant differences among the 3 study sites for all the neurobehavioral tests scores, except for digit span (backward) test. Multiple linear regression clearly shows a positive significant influence of hair As levels on all the neurobehavioral test scores, except for digit span (backward) test, after controlling for hair lead (Pb), manganese (Mn) and cadmium (Cd). Children with high hair As levels experienced 1.57–4.67 times greater risk of having lower neurobehavioral test scores compared to those with low hair As levels, after adjusting for hair Pb, Mn and Cd levels and BMI status. In conclusion, arsenic-exposed school children from the Kandal Province of Cambodia with a median hair As level of 0.93 µg/g among those from the highly contaminated study site, showed clear evidence of neurobehavioral effects. - Highlights: • We measured the level of arsenic concentration in school secondary school children's hair. • As contamination in groundwater is the major source effect on the neurobehavioral performance of school children. • School children in highly and moderately contaminated sites are at risk of As exposure.« less

Nucleotide substitutions in dengue virus serotypes from Asian and American countries: insights into intracodon recombination and purifying selection

PubMed Central

2013-01-01

Background Dengue virus (DENV) infection represents a significant public health problem in many subtropical and tropical countries. Although genetically closely related, the four serotypes of DENV differ in antigenicity for which cross protection among serotypes is limited. It is also believed that both multi-serotype infection as well as the evolution of viral antigenicity may have confounding effects in increased dengue epidemics. Numerous studies have been performed that investigated genetic diversity of DENV, but the precise mechanism(s) of dengue virus evolution are not well understood. Results We investigated genome-wide genetic diversity and nucleotide substitution patterns in the four serotypes among samples collected from different countries in Asia and Central and South America and sequenced as part of the Genome Sequencing Center for Infectious Diseases at the Broad Institute. We applied bioinformatics, statistical and coalescent simulation methods to investigate diversity of codon sequences of DENV samples representing the four serotypes. We show that fixation of nucleotide substitutions is more prominent among the inter-continental isolates (Asian and American) of serotypes 1, 2 and 3 compared to serotype 4 isolates (South and Central America) and are distributed in a non-random manner among the genes encoded by the virus. Nearly one third of the negatively selected sites are associated with fixed mutation sites within serotypes. Our results further show that of all the sites showing evidence of recombination, the majority (~84%) correspond to sites under purifying selection in the four serotypes. The analysis further shows that genetic recombination occurs within specific codons, albeit with low frequency (< 5% of all recombination sites) throughout the DENV genome of the four serotypes and reveals significant enrichment (p < 0.05) among sites under purifying selection in the virus. Conclusion The study provides the first evidence for intracodon recombination in DENV and suggests that within codons, genetic recombination has a significant role in maintaining extensive purifying selection of DENV in natural populations. Our study also suggests that fixation of beneficial mutations may lead to virus evolution via translational selection of specific sites in the DENV genome. PMID:23410119

Charcoal in organic horizon and surface mineral soil in a boreal forest postfire chronosequence of Western Quebec: stocks, depth distribution, chemical properties and a synthesis of related studies

NASA Astrophysics Data System (ADS)

Preston, Caroline M.; Simard, Martin; Bergeron, Yves; Bernard, Guy M.; Wasylishen, Roderick E.

2017-11-01

Wildfires are a major driver of carbon stocks and ecosystem development in Canadian boreal forests, but there is little information on amounts and properties of the charcoal produced. Using data and samples available from a previous study, we determined amounts, depth distribution and chemical properties of visually-determined charcoal (> 2 mm) in a boreal chronosequence in the Abitibi region of Quebec, Canada. Sites ranged from 24 to 2355 years since fire (ysf) and originated from low- and high-severity soil burns (> 5 cm or < 5 cm organic horizon unburned, respectively). Two or three pits were sampled at 1-cm depth intervals from 20 jack pine (Pinus banksiana) sites (one low severity and 19 high severity) and 31 black spruce (Picea mariana) sites (12 low severity and 19 high severity). Site-level charcoal stocks ranged from 50 to 5527 kg ha-1 with high within-site variability and lower stocks for the oldest sites. Depth distributions typically peaked around the organic-mineral interface, but some low-severity sites also had charcoal layers within the organic horizon. Means from 30 samples were 569 mg g-1 total C, 4.1 mg g-1 total N and 140 C/N (molar), with total C and C/N showing a trend of decline with time since fire, and total N showing an increase. Solid-state 13C CPMAS NMR spectra of nine samples showed high variability among the younger samples, but a trend to higher aromaticity for the older ones. A literature survey focusing on boreal forests similarly showed highly variable stocks and chemical properties of charcoal in organic horizon and upper mineral soil, with reduction of variance and lower stocks after several hundred years. This initial variation was also consistent with reports of highly variable temperatures and duration of charring in wildfires. Adding reports available for char production, and considering that most studies of char stocks and production are limited to the organic horizon (forest floor), suggests that initial production of charred material from boreal wildfires might be around 5-10 tonnes ha-1.

Reliability of an fMRI Paradigm for Emotional Processing in a Multisite Longitudinal Study

PubMed Central

Gee, Dylan G.; McEwen, Sarah C.; Forsyth, Jennifer K.; Haut, Kristen M.; Bearden, Carrie E.; Addington, Jean; Goodyear, Bradley; Cadenhead, Kristin S.; Mirzakhanian, Heline; Cornblatt, Barbara A.; Olvet, Doreen; Mathalon, Daniel H.; McGlashan, Thomas H.; Perkins, Diana O.; Belger, Aysenil; Seidman, Larry J.; Thermenos, Heidi; Tsuang, Ming T.; van Erp, Theo G.M.; Walker, Elaine F.; Hamann, Stephan; Woods, Scott W.; Constable, Todd; Cannon, Tyrone D.

2015-01-01

Multisite neuroimaging studies can facilitate the investigation of brain-related changes in many contexts, including patient groups that are relatively rare in the general population. Though multisite studies have characterized the reliability of brain activation during working memory and motor functional magnetic resonance imaging tasks, emotion processing tasks, pertinent to many clinical populations, remain less explored. A traveling participants study was conducted with eight healthy volunteers scanned twice on consecutive days at each of the eight North American Longitudinal Prodrome Study sites. Tests derived from generalizability theory showed excellent reliability in the amygdala (Eρ2=0.82), inferior frontal gyrus (IFG;Eρ2=0.83), anterior cingulate cortex (ACC;Eρ2=0.76), insula (Eρ2=0.85), and fusiform gyrus (Eρ2=0.91) for maximum activation and fair to excellent reliability in the amygdala (Eρ2=0.44), IFG (Eρ2=0.48), ACC (Eρ2=0.55), insula (Eρ2=0.42), and fusiform gyrus (Eρ2=0.83) for mean activation across sites and test days. For the amygdala, habituation (Eρ2=0.71) was more stable than mean activation. In a second investigation, data from 111 healthy individuals across sites were aggregated in a voxelwise, quantitative meta-analysis. When compared with a mixed effects model controlling for site, both approaches identified robust activation in regions consistent with expected results based on prior single-site research. Overall, regions central to emotion processing showed strong reliability in the traveling participants study and robust activation in the aggregation study. These results support the reliability of blood oxygen level-dependent signal in emotion processing areas across different sites and scanners and may inform future efforts to increase efficiency and enhance knowledge of rare conditions in the population through multisite neuroimaging paradigms. PMID:25821147

The Supraclavicular Artery Perforator Flap: A Comparative Study of Imaging Techniques Used in Preoperative Mapping.

PubMed

Sheriff, Hemin Oathman; Mahmood, Kawa Abdullah; Hamawandi, Nzar; Mirza, Aram Jamal; Hawas, Jawad; Moreno, Esther Granell; Clavero, Juan Antonio; Hankins, Christopher; Masia, Jaume

2018-05-18

 The supraclavicular artery flap is an excellent flap for head and neck reconstruction. The aim of this study is to assess imaging techniques to define the precise vascular boundaries of this flap.  Six imaging techniques were used for supraclavicular artery mapping in 65 cases; handheld Doppler, triplex ultrasound, computed tomography angiography, magnetic resonance angiography, digital subtraction angiography, and indocyanine green angiography. We checked the site of the perforators, the course of a supraclavicular artery, and anatomical mapping of the supraclavicular artery.  Handheld Doppler identified perforators' sites in 80% of the cases but showed no results for the course of the vessel. Triplex ultrasound identified the site of perforators in 52.9%, and partial mapping of the course of a supraclavicular artery in 64.7% of the cases. Computerized tomography angiography showed the site of perforators in 60%, and the course of supraclavicular artery completely in 45%, and partially in an additional 30%of the cases examined. Magnetic resonance angiography showed negative results for all parameters. Digital subtraction angiography showed the partial course of a supraclavicular artery in 62.5%, but showed no perforators. Indocyanine green angiography showed the site of perforators in 60% and a partial course of supraclavicular artery distal to perforators in 60%.Anatomical mapping of the vessel was possible with computerized tomography angiogram completely in 45%, and partially in 30%, and was also possible with indocyanine green angiography partially in 60%.  Computerized tomography angiography showed best results in the mapping of the supraclavicular artery, but with an inability to define the perforator perfusion territories, and also with risks of irradiation, while indocyanine green angiography is a good alternative as it could precisely map the superficial course of the artery and angiosomes, with no radiation exposure. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Are Adolescents Engaged in the Problematic Use of Social Networking Sites More Involved in Peer Aggression and Victimization?

PubMed

Martínez-Ferrer, Belén; Moreno, David; Musitu, Gonzalo

2018-01-01

The problematic use of social networking sites is becoming a major public health concern. Previous research has found that adolescents who engage in a problematic use of social networking sites are likely to show maladjustment problems. However, little is known about its links with peer aggression and victimization. The main goal of this study was to analyze the relationship between problematic use of online social networking sites, peer aggression -overt vs. relational and reactive vs. instrumental-, and peer victimization -overt physical and verbal, and relational-, taking into account gender and age (in early and mid-adolescence). Participants were selected using randomized cluster sampling considering school and class as clusters. A battery of instruments was applied to 1,952 adolescents' secondary students from Spain (Andalusia) (50.4% boys), aged 11 to 16 ( M = 14.07, SD = 1.39). Results showed that girls and 14-16 adolescents were more involved in a problematic use of online social networking sites. Furthermore, adolescents with high problematic use of online social networking sites were more involved in overt-reactive and instrumental-and relational-reactive and instrumental-aggressive behaviors, and self-reported higher levels of overt-physical and verbal-and relational victimization. Even though boys indicated higher levels of all types of victimization, girls with high problematic use of online social networking sites scored the highest on relational victimization. Relating to age, early adolescents (aged 11-14) with higher problematic use of online social networking sites reported the highest levels of overt verbal and relational victimization. Overall, results suggested the co-occurrence of problematic use of online social networking sites, peer aggression and victimization. In addition, results showed the influence that gender and age had on peer victimization. This study highlights the continuity between offline and online domains with regard to maladjustment problems in adolescence.

Are Adolescents Engaged in the Problematic Use of Social Networking Sites More Involved in Peer Aggression and Victimization?

PubMed Central

Martínez-Ferrer, Belén; Moreno, David; Musitu, Gonzalo

2018-01-01

The problematic use of social networking sites is becoming a major public health concern. Previous research has found that adolescents who engage in a problematic use of social networking sites are likely to show maladjustment problems. However, little is known about its links with peer aggression and victimization. The main goal of this study was to analyze the relationship between problematic use of online social networking sites, peer aggression –overt vs. relational and reactive vs. instrumental–, and peer victimization –overt physical and verbal, and relational–, taking into account gender and age (in early and mid-adolescence). Participants were selected using randomized cluster sampling considering school and class as clusters. A battery of instruments was applied to 1,952 adolescents' secondary students from Spain (Andalusia) (50.4% boys), aged 11 to 16 (M = 14.07, SD = 1.39). Results showed that girls and 14–16 adolescents were more involved in a problematic use of online social networking sites. Furthermore, adolescents with high problematic use of online social networking sites were more involved in overt—reactive and instrumental—and relational—reactive and instrumental—aggressive behaviors, and self-reported higher levels of overt—physical and verbal—and relational victimization. Even though boys indicated higher levels of all types of victimization, girls with high problematic use of online social networking sites scored the highest on relational victimization. Relating to age, early adolescents (aged 11–14) with higher problematic use of online social networking sites reported the highest levels of overt verbal and relational victimization. Overall, results suggested the co-occurrence of problematic use of online social networking sites, peer aggression and victimization. In addition, results showed the influence that gender and age had on peer victimization. This study highlights the continuity between offline and online domains with regard to maladjustment problems in adolescence. PMID:29896139

Single Molecule Analysis of Replicated DNA Reveals the Usage of Multiple KSHV Genome Regions for Latent Replication

PubMed Central

Verma, Subhash C.; Lu, Jie; Cai, Qiliang; Kosiyatrakul, Settapong; McDowell, Maria E.; Schildkraut, Carl L.; Robertson, Erle S.

2011-01-01

Kaposi's sarcoma associated herpesvirus (KSHV), an etiologic agent of Kaposi's sarcoma, Body Cavity Based Lymphoma and Multicentric Castleman's Disease, establishes lifelong latency in infected cells. The KSHV genome tethers to the host chromosome with the help of a latency associated nuclear antigen (LANA). Additionally, LANA supports replication of the latent origins within the terminal repeats by recruiting cellular factors. Our previous studies identified and characterized another latent origin, which supported the replication of plasmids ex-vivo without LANA expression in trans. Therefore identification of an additional origin site prompted us to analyze the entire KSHV genome for replication initiation sites using single molecule analysis of replicated DNA (SMARD). Our results showed that replication of DNA can initiate throughout the KSHV genome and the usage of these regions is not conserved in two different KSHV strains investigated. SMARD also showed that the utilization of multiple replication initiation sites occurs across large regions of the genome rather than a specified sequence. The replication origin of the terminal repeats showed only a slight preference for their usage indicating that LANA dependent origin at the terminal repeats (TR) plays only a limited role in genome duplication. Furthermore, we performed chromatin immunoprecipitation for ORC2 and MCM3, which are part of the pre-replication initiation complex to determine the genomic sites where these proteins accumulate, to provide further characterization of potential replication initiation sites on the KSHV genome. The ChIP data confirmed accumulation of these pre-RC proteins at multiple genomic sites in a cell cycle dependent manner. Our data also show that both the frequency and the sites of replication initiation vary within the two KSHV genomes studied here, suggesting that initiation of replication is likely to be affected by the genomic context rather than the DNA sequences. PMID:22072974

Site specific interaction between ZnO nanoparticles and tyrosine: A density functional theory study

NASA Astrophysics Data System (ADS)

Singh, Satvinder; Singh, Janpreet; Singh, Baljinder; Singh, Gurinder; Kaura, Aman; Tripathi, S. K.

2018-05-01

First Principles Calculations have been performed on ZnO/Tyrosine atomic complex to study site specific interaction of Tyrosine and ZnO nanoparticles. Calculated results shows that -COOH group present in Tyrosine is energetically more favorable than -NH2 group. Interactions show ionic bonding between ZnO and Tyrosine. All the calculations have been performed under the Density Functional Theory (DFT) framework. Structural and electronic properties of (ZnO)3/Tyrosine complex have been studied. Gaussian basis set approach has been adopted for the calculations. A ring type most stable (ZnO)3 atomic cluster has been modeled, analyzed and used for the calculations.

Finger printing of mixed contaminants from former manufactured gas plant (MGP) site soils: Implications to bioremediation.

PubMed

Thavamani, Palanisami; Megharaj, Mallavarapu; Krishnamurti, G S R; McFarland, Ross; Naidu, Ravi

2011-01-01

Contaminants in general do not occur as single chemicals but as mixtures at any contaminated site. Gasworks sites are the typical mixed contaminated sites. These sites are not only subjected to PAH contamination but also varying degrees of heavy metal contamination. Bioremediation in these sites is often hindered by the presence of heavy metals. The co-occurrence of PAHs with heavy metals has not been systematically investigated. Metals are reported to inhibit the general soil microbiological processes. The total concentration of soluble metal in the system includes both free metal ion and complexed forms. Within bioavailable fraction, the most toxic form is the free metal species, which was not addressed well so far in gas works site characterisation. This study underpins the science and importance of metal bioavailability and speciation based site characterisation in mixed contaminated sites. In this study a detailed elemental chemistry of the gas works site soils are discussed using different methods. The PAH contamination was contributed by both low and high molecular weight PAHs. The total PAHs concentration ranged from 335 to 8645 mg/kg. Among most toxic metals Pb was found in high concentration ranging from 88 to 671 mg/kg, Cd 8 to 112 mg/kg and Zn varied from 64 to 488 mg/kg. Thermodynamic chemical equilibrium model VMINTEQ (Ver 2.52) was used to calculate the free metal species in gas works site soils. The percentage free metal species showed a different trend compared to total metal concentrations, free Zn species ranged 18-86%, free Cd was 26-87% and Pb showed lowest free metal percentage (0-17%). The bioavailable metal species and its implications to bioremediation have also been discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Cold-induced vasoconstriction at forearm and hand skin sites: the effect of age

PubMed Central

Frijns, A. J. H.; Saris, W. H. M.; van Steenhoven, A. A.; van Marken Lichtenbelt, W. D.

2010-01-01

During mild cold exposure, elderly are at risk of hypothermia. In humans, glabrous skin at the hands is well adapted as a heat exchanger. Evidence exists that elderly show equal vasoconstriction due to local cooling at the ventral forearm, yet no age effects on vasoconstriction at hand skin have been studied. Here, we tested the hypotheses that at hand sites (a) elderly show equal vasoconstriction due to local cooling and (b) elderly show reduced response to noradrenergic stimuli. Skin perfusion and mean arterial pressure were measured in 16 young adults (Y: 18–28 years) and 16 elderly (E: 68–78 years). To study the effect of local vasoconstriction mechanisms local sympathetic nerve terminals were blocked by bretylium (BR). Baseline local skin temperature was clamped at 33°C. Next, local temperature was reduced to 24°C. After 15 min of local cooling, noradrenalin (NA) was administered to study the effect of neural vasoconstriction mechanisms. No significant age effect was observed in vasoconstriction due to local cooling at BR sites. After NA, vasoconstriction at the forearm showed a significant age effect; however, no significant age effect was found at the hand sites. [Change in CVC (% from baseline): Forearm Y: −76 ± 3 vs. E: −60 ± 5 (P < 0.01), dorsal hand Y: −74 ± 4 vs. E: −72 ± 4 (n.s.), ventral hand Y: −80 ± 7 vs. E: −70 ± 11 (n.s.)]. In conclusion, in contrast to results from the ventral forearm, elderly did not show a blunted response to local cooling and noradrenalin at hand skin sites. This indicates that at hand skin the noradrenergic mechanism of vasoconstriction is maintained with age. PMID:20300768

A review of negative-pressure wound therapy in the management of burn wounds.

PubMed

Kantak, Neelesh A; Mistry, Riyam; Halvorson, Eric G

2016-12-01

Negative pressure has been employed in various aspects of burn care and the aim of this study was to evaluate the evidence for each of those uses. The PubMed and Cochrane CENTRAL databases were queried for articles in the following areas: negative pressure as a dressing for acute burns, intermediate treatment prior to skin grafting, bolster for skin autografts, dressing for integration of dermal substitutes, dressing for skin graft donor sites, and integrated dressing in large burns. Fifteen studies met our inclusion criteria. One study showed negative pressure wound therapy improved perfusion in acute partial-thickness burns, 8 out of 9 studies showed benefits when used as a skin graft bolster dressing, 1 out of 2 studies showed improved rate of revascularization when used over dermal substitutes, and 1 study showed increased rate of re-epithelialization when used over skin graft donor sites. Negative pressure can improve autograft take when used as a bolster dressing. There is limited data to suggest that it may also improve the rate of revascularization of dermal substitutes and promote re-epithelialization of skin graft donor sites. Other uses suggested by studies that did not meet our inclusion criteria include improving vascularity in acute partial-thickness burns and as an integrated dressing for the management of large burns. Further studies are warranted for most clinical applications to establish negative pressure as an effective adjunct in burn wound care. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Ground motion in Anchorage, Alaska, from the 2002 Denali fault earthquake: Site response and Displacement Pulses

USGS Publications Warehouse

Boore, D.M.

2004-01-01

Data from the 2002 Denali fault earthquake recorded at 26 sites in and near Anchorage, Alaska, show a number of systematic features important in studies of site response and in constructing long-period spectra for use in earthquake engineering. The data demonstrate that National Earthquake Hazards Reduction Program (NEHRP) site classes are a useful way of grouping stations according to site amplification. In general, the sites underlain by lower shear-wave velocities have higher amplification. The amplification on NEHRP class D sites exceeds a factor of 2 relative to an average of motions on class C sites. The amplifications are period dependent. They are in rough agreement with those from previous studies, but the new data show that the amplifications extend to at least 10 sec, periods longer than considered in previous studies. At periods longer than about 14 sec, all sites have motion of similar amplitude, and the ground displacements are similar in shape, polarization, and amplitude for all stations. The displacement ground motion is dominated by a series of four pulses, which are associated with the three subevents identified in inversion studies (the first pulse is composed of P waves from the first subevent). Most of the high-frequency ground motion is associated with the S waves from subevent 1. The pulses from subevents 1 and 2, with moment releases corresponding to M 7.1 and 7.0, are similar to the pulse of displacement radiated by the M 7.1 Hector Mine earthquake. The signature from the largest subevent (M 7.6) is more subdued than those from the first two subevents. The two largest pulses produce response spectra with peaks at a period of about 15 sec. The spectral shape at long periods is in good agreement with the recent 2003 NEHRP code spectra but is in poor agreement with the shape obtained from Eurocode 8.

The SAT: An Essay in Uncertainty

ERIC Educational Resources Information Center

Mlodinow, Leonard

2008-01-01

In this article, the author talks about the release of the most comprehensive study of SAT exams. The headline on the Web site of the College Board, the maker of the test, was, "SAT Studies Show Test's Strength in Predicting College Success." At the same time, a headline on the Web site of the group FairTest, a 23-year-old, nonprofit…

Multi-hierarchical movements in self-avoiding walks

NASA Astrophysics Data System (ADS)

Sakiyama, Tomoko; Gunji, Yukio-Pegio

2017-07-01

A self-avoiding walk (SAW) is a series of moves on a lattice that visit the same place only once. Several studies reported that repellent reactions of foragers to previously visited sites induced power-law tailed SAWs in animals. In this paper, we show that modelling the agent's multi-avoidance reactions to its trails enables it to show ballistic movements which result in heavy-tailed movements. There is no literature showing emergent ballistic movements in SAWs. While following SAWs, the agent in my model changed its reactions to marked patches (visited sites) by considering global trail patterns based on local trail patterns when the agent was surrounded by previously visited sites. As a result, we succeeded in producing ballistic walks by the agents which exhibited emergent power-law tailed movements.

Oxygen microprofile in the prepared sediments and its implication for the sediment oxygen consuming process in a heavily polluted river of China.

PubMed

Wang, Chao; Zhai, Wanying; Shan, Baoqing

2016-05-01

Dissolved oxygen (DO) microprofiles of prepared sediments from 24 sampling sites in the Fuyang River were measured using a gold amalgam microelectrode in this study. The measured microprofiles can be divided into four types. In type I profiles, DO kept constant in the overlying water and decreased smoothly in the pore water; in type II profile, DO showed fluctuation in the pore water; in type III profiles, DO showed peak in the SWI; in type IV profiles, DO decreased obviously in the overlying water. Type I profiles indicated the absence of benthic organisms and thus the degradation of the sediment habitat. Type II and III profiles indicated the activity of benthic animal and epipelic algae, which is common in the healthy aquatic sediment. Type IV profiles indicated that the excessive accumulation of pollutants in the sediment and thus the serious sediment pollution. There are nine sites showing type I profile, three sites showing type II profile, nine sites showing type III profile, and three sites showing type IV profile in the Fuyang River. The dominance of type I and appearance of type IV indicated that sediment oxygen consumption processes in the Fuyang River were strongly influenced by the sediment pollutants release and the vanish of benthic organisms. The pharmacy, metallurgy, and curriery industries may contribute to the sediment deterioration and thus to the occurrence of type I and type IV oxygen profiles in the Fuyang River.

Malignant melanoma in Chile: different site distribution between private and state patients.

PubMed

Zemelman, Viviana B; Valenzuela, Carlos Y; Sazunic, Ivo; Araya, Irene

2014-01-01

The body site location of primary Malignant Melanoma (MM) has been correlated with prognosis and survival. Ethnic, genetics, sun exposure factors are related to the anatomical distribution of MM. Low and high socioeconomic strata in Chile differ in ethnic, genetic and cultural conditions. The purpose of this study was to analyze the anatomical MM distribution in the Chilean population in both strata searching for differences due to their ethno-genetic-cultural differences. Records of 1148 MM, 575 cases from state hospitals (Low Socioeconomic Strata, LSS) and 573 cases from private clinics (High Socioeconomic Strata, HSS) were analyzed by body site. Females from LSS showed a higher number of MM in soles, cheeks, and around the eye area. Females from the HSS showed a higher number of MM in dorsal feet and dorsal hands. Males from LSS showed a higher number of MM in soles, around the eye area, and cheeks. However, males from HSS showed a higher number of MM in the trunk, and in the arms. Acral MM was significantly higher in LSS than in the HSS in both sexes. The Chilean population from the HSS and LSS showed differences in the distribution of MM by site. Furthermore, gender differences in the proportion of MM analyzed by anatomical site are observed in both strata. Results show evidence that differential genetics factors, sun exposure, or other environmental or cultural factors of both strata may account for these differences.

Seasonal variation in imposex intensity of Thais clavigera

NASA Astrophysics Data System (ADS)

Li, Zhengyan

2005-06-01

Imposex, specifically caused by TBT pollution, refers to the superimposition of male sexual characteristics in gastropod females. Seasonal variation of imposex intensity in Thais clavigera from both slightly and severely contaminated sites in Hong Kong waters was studied from 1988 to 1999. The male penis length showed significant difference between both sites and seasons. It was shortest during late autumn and early winter (October to December) and longest during spring and early summer (February to June). Female penis length also showed significant difference between sites. It did not change seasonally, however. The RPS (Relative Penis Size) index was the highest during autumn and early winter, and the lowest during spring and early summer. The VDS (Vas Deferens Sequence) index remained stable throughout the sampling period. This study showed that VDS index is a better indicator when we compare relative intensity of imposex. The comparison can only be meaningful provided the samples from different locations are taken during the same season.

How long is enough to detect terrestrial animals? Estimating the minimum trapping effort on camera traps

PubMed Central

Si, Xingfeng; Kays, Roland

2014-01-01

Camera traps is an important wildlife inventory tool for estimating species diversity at a site. Knowing what minimum trapping effort is needed to detect target species is also important to designing efficient studies, considering both the number of camera locations, and survey length. Here, we take advantage of a two-year camera trapping dataset from a small (24-ha) study plot in Gutianshan National Nature Reserve, eastern China to estimate the minimum trapping effort actually needed to sample the wildlife community. We also evaluated the relative value of adding new camera sites or running cameras for a longer period at one site. The full dataset includes 1727 independent photographs captured during 13,824 camera days, documenting 10 resident terrestrial species of birds and mammals. Our rarefaction analysis shows that a minimum of 931 camera days would be needed to detect the resident species sufficiently in the plot, and c. 8700 camera days to detect all 10 resident species. In terms of detecting a diversity of species, the optimal sampling period for one camera site was c. 40, or long enough to record about 20 independent photographs. Our analysis of evaluating the increasing number of additional camera sites shows that rotating cameras to new sites would be more efficient for measuring species richness than leaving cameras at fewer sites for a longer period. PMID:24868493

Distribution of chemical warfare agent, energetics, and metals in sediments at a deep-water discarded military munitions site

NASA Astrophysics Data System (ADS)

Briggs, Christian; Shjegstad, Sonia M.; Silva, Jeff A. K.; Edwards, Margo H.

2016-06-01

There is a strong need to understand the behavior of chemical warfare agent (CWA) at underwater discarded military munitions (DMM) sites to determine the potential threat to human health or the environment, yet few studies have been conducted at sites in excess of 250 m, the depth at which most U.S. chemical munitions were disposed. As part of the Hawai'i Undersea Military Munitions Assessment (HUMMA), sediments adjacent to chemical and conventional DMM at depths of 400-650 m were sampled using human occupied vehicles (HOVs) in order to quantify the distribution of CWA, energetics, and select metals. Sites in the same general area, with no munitions within 50 m in any direction were sampled as a control. Sulfur mustard (HD) and its degradation product 1,4-dithiane were detected at each CWA DMM site, as well as a single sample with the HD degradation product 1,4-thioxane. An energetic compound was detected in sediment to a limited extent at one CWA DMM site. Metals common in munitions casings (i.e., Fe, Cu, and Pb) showed similar trends at the regional and site-wide scales, likely reflecting changes in marine sediment deposition and composition. This study shows HD and its degradation products can persist in the deep-marine environment for decades following munitions disposal.

An integrated CRISPR Bombyx mori genome editing system with improved efficiency and expanded target sites.

PubMed

Ma, Sanyuan; Liu, Yue; Liu, Yuanyuan; Chang, Jiasong; Zhang, Tong; Wang, Xiaogang; Shi, Run; Lu, Wei; Xia, Xiaojuan; Zhao, Ping; Xia, Qingyou

2017-04-01

Genome editing enabled unprecedented new opportunities for targeted genomic engineering of a wide variety of organisms ranging from microbes, plants, animals and even human embryos. The serial establishing and rapid applications of genome editing tools significantly accelerated Bombyx mori (B. mori) research during the past years. However, the only CRISPR system in B. mori was the commonly used SpCas9, which only recognize target sites containing NGG PAM sequence. In the present study, we first improve the efficiency of our previous established SpCas9 system by 3.5 folds. The improved high efficiency was also observed at several loci in both BmNs cells and B. mori embryos. Then to expand the target sites, we showed that two newly discovered CRISPR system, SaCas9 and AsCpf1, could also induce highly efficient site-specific genome editing in BmNs cells, and constructed an integrated CRISPR system. Genome-wide analysis of targetable sites was further conducted and showed that the integrated system cover 69,144,399 sites in B. mori genome, and one site could be found in every 6.5 bp. The efficiency and resolution of this CRISPR platform will probably accelerate both fundamental researches and applicable studies in B. mori, and perhaps other insects. Copyright © 2017 Elsevier Ltd. All rights reserved.

Flood prevention dams for arid regions at a micro-scale sub-catchment, case study: Tabuk, Saudi Arabia.

PubMed

Abushandi, Eyad

2016-12-01

Unexpected flash flooding is one of the periodic hydrological problems affecting the city of Tabuk in Saudi Arabia. The region has high potential for floods as it suffers high rainfall intensity in a short time and also has high urbanization rates and topographic complexity. Constructing flood prevention dams is one option to solve this problem. A cost-effective design requires a detailed feasibility study and analysis for the selection of suitable sites. The aim of this study was to develop a method for selecting a suitable site for flood protection dams in the Abu Saba'a district, the most affected part of the city of Tabuk during the flash flood in January 2013. Spatial analysis was applied using Landsat Thematic Mapper images and Shuttle Radar Topography Mission digital elevation model to select a site in the Abu Saba'a area. A simple model using ArcGIS was built including all suggested parameters. The results showed the best site for a dam was 2 km distance backfrom the area, where all parameter values matched. The results showed that the dynamic properties of land cover can affect site selection. It is therefore suggested that more field and hydrological data should be gathered for greater accuracy.

Multi-level stressor analysis from the DNA/biochemical level to community levels in an urban stream and integrative health response (IHR) assessments.

PubMed

Lee, Jae Hoon; Kim, Joon Ha; Oh, Hee-Mock; An, Kwang-Guk

2013-01-01

The objectives of this study were to identify multi-level stressors at the DNA/biochemical level to the community level in fish in an urban stream and to develop an integrative health response (IHR) model for ecological health diagnosis. A pristine control site (S (c) ) and an impacted site (S (i) ) were selected from among seven pre-screened sites studied over seven years. Various chemical analyses indicated that nutrient enrichment (Nitrogen, Phosphorus) and organic pollution were significantly greater (t > 8.783, p < 0.01) at the S (i) site compared to the S (c) site. Single-cell gel electrophoresis (comet assays) of DNA-level impairment indicated significantly (t = 5.678, p < 0.01) greater tail intensity, expressed as % tail-DNA, at the S (i) site and genotoxic responses were detected in the downstream reach. Ethoxyresorufin-O-deethylase (EROD) assays, as a physiological bioindicator, were 2.8-fold higher (p < 0.05, NK-test after ANOVA) at the S (i) site. Tissue analysis using a necropsy-based health assessment index (NHAI) showed distinct internal organ disorders in three tissues, i.e., liver, kidney, and gill, at the S (i) site. Population-level analysis using the sentinel species Zacco platypus showed that the regression coefficient (b) was 3.012 for the S (i) site and 2.915 for the S (c) site, indicating population skewness in the downstream reach. Community-level health was impaired at the S (i) site based on an index of biological integrity (IBI), and physical habitat modifications were identified by a qualitative habitat evaluation index (QHEI). Overall, the model values for the integrative health response (IHR), developed using the star plot approach, were 3.22 (80.5%) at the S (c) site and 0.74 (18.5%) at the S (i) site, indicating that, overall, ecological health impairments were evident in the urban reach. Our study was based on multi-level approaches using biological organization and the results suggest that there is a pivotal point of linkage between mechanistic understanding and real ecological consequences of environmental stressors.

Influence of Stepped Osteotomy on Primary Stability of Implants Inserted in Low-Density Bone Sites: An In Vitro Study.

PubMed

Degidi, Marco; Daprile, Giuseppe; Piattelli, Adriano

The aims of this study were to evaluate the ability of a stepped osteotomy to improve dental implant primary stability in low-density bone sites and to investigate possible correlations between primary stability parameters. The study was performed on fresh humid bovine bone classified as type III. The test group consisted of 30 Astra Tech EV implants inserted following the protocol provided by the manufacturer. The first control group consisted of 30 Astra Tech EV implants inserted in sites without the underpreparation of the apical portion. The second control group consisted of 30 Astra Tech TX implants inserted following the protocol provided by the manufacturer. Implant insertion was performed at the predetermined 30 rpm. The insertion torque data were recorded and exported as a curve; using a trapezoidal integration technique, the area underlying the curve was calculated: this area represents the variable torque work (VTW). Peak insertion torque (pIT) and resonance frequency analysis (RFA) were also recorded. A Mann-Whitney test showed that the mean VTW was significantly higher in the test group compared with the first control and second control groups; furthermore, statistical analysis showed that pIT also was significantly higher in the test group compared with the first and second control groups. Analyzing RFA values, only the difference between the test group and second control group showed statistical significance. Pearson correlation analysis showed a very strong positive correlation between pIT and VTW values in all groups; furthermore, it showed a positive correlation between pIT and RFA values and between VTW and RFA values only in the test group. Within the limitations of an in vitro study, the results show that stepped osteotomy can be a viable method to improve implant primary stability in low-density bone sites, and that, when a traditional osteotomy method is performed, RFA presents no correlation with pIT and VTW.

Dispersed Volcanic Ash in Sediment Entering NW Pacific Ocean Subduction Zones: Towards a Regional Perspective

NASA Astrophysics Data System (ADS)

Scudder, R. P.; Murray, R. W.; Underwood, M.; Kutterolf, S.; Plank, T.; Dyonisius, M.; Arshad, M. A.

2011-12-01

Volcanic ash has long been recognized to be an important component of the global sedimentary system. Ash figures prominently in a number of sedimentary and petrophysical investigations, including how the fluid budget of subducting sediment will be affected by hydration/dehydration reactions. Additionally, many studies focus on discrete ash layers, and how to link their presence with volcanism, climate, arc evolution, biological productivity, and other processes. Less widely recognized is the ash that is mixed into the bulk sediment, or "dispersed" ash. Dispersed ash is quantitatively significant and is an under-utilized source of critical geochemical and tectonic information. Based on geochemical studies of ODP Site 1149, a composite of DSDP Sites 579 & 581, as well as IODP Sites C0011 & C0012 drilled during Expedition 322, we will show the importance of dispersed ash to the Izu-Bonin-Marianas, Kurile-Kamchatka and Nankai subduction zones. Initial geochemical analyses of the bulk sediment, as related to dispersed ash entering these subduction systems are presented here. Geochemical analysis shows that the characteristics of the three sites exhibit some variability consistent with observed lithological variations. For example, the average SiO2/Al2O3 ratios at Site 1149, Site C0011 and Site C0012 average 3.7. The composite of Sites 579 & 581 exhibits a higher average of 4.6. There are contrasts between other key major elemental indicators as well (e.g., Fe2O3). Ternary diagrams such as K2O-Na2O-CaO show that there are at least two distinct geochemical fields with Sites 1149, C0011 and C0012 clustering in one and Sites 579 & 581 in the other. Q-mode Factor Analysis was performed on the bulk sediment chemical data in order to determine the composition of potential end members of these sites. The multivariate statistics indicate that Site 1149 has 3-4 end members, consistent with the results of Scudder et al. (2009, EPSL, v. 284, pp 639), while each of the other sites has 4-5 end members. These geochemical signatures (e.g., K2O) of the dispersed ash can be exploited to provide insight into the importance of clay mineralogy (i.e., smectite). Additional results from trace and REE analyses, combined with additional statistical treatments, will also be presented.

Fibrosarcomas at presumed sites of injection in dogs: characteristics and comparison with non-vaccination site fibrosarcomas and feline post-vaccinal fibrosarcomas.

PubMed

Vascellari, M; Melchiotti, E; Bozza, M A; Mutinelli, F

2003-08-01

Fifteen fibrosarcomas, surgically excised from presumed sites of injection in dogs, and 10 canine fibrosarcomas excised from sites not used for injection were histologically and immunohistochemically compared with 20 feline post-vaccinal fibrosarcomas. Canine fibrosarcomas from presumed injection sites were of grade I (3), of grade II (4) and grade III (8). Two fibrosarcomas from non-injection sites were of grade I, four of grade II and four of grade III. Feline samples were classified as grade I (2), grade II (4) and grade III (14). All fibrosarcomas from presumed injection sites of both species showed lymphocytic inflammatory infiltration located at the tumour periphery, while two canine fibrosarcomas from non-injection sites showed perivascular inflammatory infiltration within the neoplasm. All samples were immunohistochemically examined for vimentin, smooth muscle actin, muscle specific actin and desmin expression. All tumours were positive for vimentin. Ten canine fibrosarcomas from presumed injection sites and all feline samples contained cells consistent with a myofibroblastic immunophenotype. Aluminium deposits were detected in eight canine fibrosarcomas from presumed injection sites and 11 feline post-vaccinal fibrosarcomas by the aurintricarboxylic acid method. The present study identifies distinct similarities between canine fibrosarcomas from presumed injection sites and feline post-vaccinal fibrosarcomas, suggesting the possibility of the development of post-injection sarcomas not only in cats, but also in dogs.

Time-of-travel data for Nebraska streams, 1968 to 1977

USGS Publications Warehouse

Petri, L.R.

1984-01-01

This report documents the results of 10 time-of-travel studies, using ' dye-tracer ' methods, conducted on five streams in Nebraska during the period 1968 to 1977. Streams involved in the studies were the North Platte, North Loup, Elkhorn, and Big Blue Rivers and Salt Creek. Rhodamine WT dye in a 20 percent solution was used as the tracer for all 10 time-of-travel studies. Water samples were collected at several points below each injection site. Concentrations of dye in the samples were measured by determining fluorescence of the sample and comparing that value to fluorescence-concentration curves. Stream discharges were measured before and during each study. Results of each time-by-travel study are shown on two tables and on graph. The first table shows water discharge at injection and sampling sites, distance between sites, and time and rate of travel of the dye between sites. The second table provides descriptions of study sites, amounts of dye injected in the streams, actual sampling times, and actual concentrations of dye detected. The graphs for each time-of-travel study provide indications of changing travel rates between sampling sites, information on length of dye clouds, and times for dye passage past given points. (USGS)

KSC00pp0920

NASA Image and Video Library

2000-06-20

CO2 study site manager and plant physiologist Graham Hymus (left) examines scrub oak foliage while project engineer David Johnson (right) looks on. The life sciences study is showing that rising levels of carbon dioxide in our atmosphere, caused by the burning of fossil fuels, could spur plant growth globally. The site of KSC's study is a natural scrub oak area near the Vehicle Assembly Building. Twelve-foot areas of scrub oak have been enclosed in 16 open-top test chambers into which CO2 has been blown. Five scientists from NASA and the Smithsonian Environmental Research Center in Edgewater, Md., work at the site to monitor experiments and keep the site running. Scientists hope to continue the study another five to 10 years. More information on this study can be found in Release No. 57-00. Additional photos can be found at: www-pao.ksc.nasa.gov/captions/subjects/co2study.htm

KSC-00pp0920

NASA Image and Video Library

2000-06-20

CO2 study site manager and plant physiologist Graham Hymus (left) examines scrub oak foliage while project engineer David Johnson (right) looks on. The life sciences study is showing that rising levels of carbon dioxide in our atmosphere, caused by the burning of fossil fuels, could spur plant growth globally. The site of KSC's study is a natural scrub oak area near the Vehicle Assembly Building. Twelve-foot areas of scrub oak have been enclosed in 16 open-top test chambers into which CO2 has been blown. Five scientists from NASA and the Smithsonian Environmental Research Center in Edgewater, Md., work at the site to monitor experiments and keep the site running. Scientists hope to continue the study another five to 10 years. More information on this study can be found in Release No. 57-00. Additional photos can be found at: www-pao.ksc.nasa.gov/captions/subjects/co2study.htm

Geophysical Investigations Over the Archaeological site of Rirha (Morocco)

NASA Astrophysics Data System (ADS)

Senechal, G.; Rousset, D.; Callegarin, L.; Kbiri Alaoui, M.

2007-05-01

The roman site of Rirha has been evidenced in the 1920's and loosely studied until nowadays. Archeaological evidences show a pre-roman to medieval occupation of the site. Excavations have revealed thermae and other buildings while their context, rural villa or urban domus was still unknown. A new survey began in 2004, focusing on the pre-roman occupation of the site, as well as the characterization of the roman occupation. The zone of interest, a hill in a river loop, is about 11hectares. A comprehensive geophysical survey was out of reach, so geophysical tests have been carried on with two goals. The first one was to identify the suitable methods adapted to this, the second one was to use these preliminary results to distinguish between rural or urban settings for the roman site. The first survey has been conducted in April 2005, using conductivitymeter (Geonics EM38) in order to get informations about the spatial organization of the site. The selected zone was located in an unsurveyed part of the site. Resistivity maps show orthogonal structures, far from the known roman remains. This result supports the hypothesis of the site being a roman town and not a large farm or a villa. The second survey has been carried on in February 2006 and involved GPR and DC tomography, in very wet conditions. DC survey aimed at constraining the geological context of the site and at finding the remains of a large wall described by early authors. GPR experiment was primarily a test of the tool there and has been conducted on the previously studied area to get some depth information. The geological context has been studied by carrying on a 2D vertical section, 330 m long and 25 meters deep. showing a substratum of river deposit (sand, gravel, pebbles with possible clay layers) located at 8 to 10 m deep. Above this formation, we observe a very conductive layer interpreted as a clay formation (3 to 6 m thick) and finally, just below the surface, a laterally heterogeneous formation with rocks and adobe masonry. 2D DC sections succesfully located the remains of the surrounding wall of the site supporting even more the town hypothesis. GPR 3D results (250 MHz) are in agreement with conductivity maps but are of poor quality due to the very low resistivity of the soil.

Atmospheric particulate matter in proximity to mountaintop coal mines: Sources and potential environmental and human health impacts

USGS Publications Warehouse

Kurth, Laura; Kolker, Allan; Engle, Mark A.; Geboy, Nicholas J.; Hendryx, Michael; Orem, William H.; McCawley, Michael; Crosby, Lynn M.; Tatu, Calin A.; Varonka, Matthew S.; DeVera, Christina A.

2015-01-01

Mountaintop removal mining (MTM) is a widely used approach to surface coal mining in the US Appalachian region whereby large volumes of coal overburden are excavated using explosives, removed, and transferred to nearby drainages below MTM operations. To investigate the air quality impact of MTM, the geochemical characteristics of atmospheric particulate matter (PM) from five surface mining sites in south central West Virginia, USA, and five in-state study control sites having only underground coal mining or no coal mining whatsoever were determined and compared. Epidemiologic studies show increased rates of cancer, respiratory disease, cardiovascular disease, and overall mortality in Appalachian surface mining areas compared to Appalachian non-mining areas. In the present study, 24-h coarse (>2.5 µm) and fine (≤2.5 µm) PM samples were collected from two surface mining sites in June 2011 showed pronounced enrichment in elements having a crustal affinity (Ga, Al, Ge, Rb, La, Ce) contributed by local sources, relative to controls. Follow-up sampling in August 2011 lacked this enrichment, suggesting that PM input from local sources is intermittent. Using passive samplers, dry deposition total PM elemental fluxes calculated for three surface mining sites over multi-day intervals between May and August 2012 were 5.8 ± 1.5 times higher for crustal elements than at controls. Scanning microscopy of 2,249 particles showed that primary aluminosilicate PM was prevalent at surface mining sites compared to secondary PM at controls. Additional testing is needed to establish any link between input of lithogenic PM and disease rates in the study area.

Atmospheric particulate matter in proximity to mountaintop coal mines: sources and potential environmental and human health impacts.

PubMed

Kurth, Laura; Kolker, Allan; Engle, Mark; Geboy, Nicholas; Hendryx, Michael; Orem, William; McCawley, Michael; Crosby, Lynn; Tatu, Calin; Varonka, Matthew; DeVera, Christina

2015-06-01

Mountaintop removal mining (MTM) is a widely used approach to surface coal mining in the US Appalachian region whereby large volumes of coal overburden are excavated using explosives, removed, and transferred to nearby drainages below MTM operations. To investigate the air quality impact of MTM, the geochemical characteristics of atmospheric particulate matter (PM) from five surface mining sites in south central West Virginia, USA, and five in-state study control sites having only underground coal mining or no coal mining whatsoever were determined and compared. Epidemiologic studies show increased rates of cancer, respiratory disease, cardiovascular disease, and overall mortality in Appalachian surface mining areas compared to Appalachian non-mining areas. In the present study, 24-h coarse (>2.5 µm) and fine (≤2.5 µm) PM samples were collected from two surface mining sites in June 2011 showed pronounced enrichment in elements having a crustal affinity (Ga, Al, Ge, Rb, La, Ce) contributed by local sources, relative to controls. Follow-up sampling in August 2011 lacked this enrichment, suggesting that PM input from local sources is intermittent. Using passive samplers, dry deposition total PM elemental fluxes calculated for three surface mining sites over multi-day intervals between May and August 2012 were 5.8 ± 1.5 times higher for crustal elements than at controls. Scanning microscopy of 2,249 particles showed that primary aluminosilicate PM was prevalent at surface mining sites compared to secondary PM at controls. Additional testing is needed to establish any link between input of lithogenic PM and disease rates in the study area.

Geophysical Responses of Hydrocarbon-impacted Zones at the Various Contamination Conditions

NASA Astrophysics Data System (ADS)

Kim, C.; Ko, K.; Son, J.; Kim, J.

2008-12-01

One controlled experiment and two field surveys were conducted to investigate the geoelectrical responses of hydrocarbon-contaminated zones, so called smeared zone, on the geophysical data at the hydrocarbon- contaminated sites with various conditions. One controlled physical model experiment with GPR using fresh gasoline and two different 3-D electrical resistivity investigations at the aged sites. One field site (former military facilities for arms maintenance) was mainly contaminated with lubricating oils and the other (former gas station) was contaminated with gasoline and diesel, respectively. The results from the physical model experiment show that GPR signals were enhanced when LNAPL was present as a residual saturation in the water-saturated system due to less attenuation of the electromagnetic energy through the soil medium of the hydrocarbon-impacted zone (no biodegradation), compared to when the medium was saturated with only water (no hydrocarbon impaction). In the former gas station site, 3-D resistivity results demonstrate that the highly contaminated zones were imaged with low resistivity anomalies since the biodegradation of petroleum hydrocarbons has been undergone for many years, causing the drastic increase in the TDS at the hydrocarbon-impacted zones. Finally, 3-D resistivity data obtained from the former military maintenance site show that the hydrocarbon-contaminated zones show high resistivity anomalies since the hydrocarbons such as lubricating oils at the contaminated soils were not greatly influenced by microbial degradation and has relatively well kept their original physical properties of high electrical resistivity. The results of the study illustrated that the hydrocarbon-impacted zones under various contamination conditions yielded various geophysical responses which include (1) enhanced GPR amplitudes at the fresh LNAPL (Gasoline to middle distillates) spill sites, (2) low electrical resistivity anomalies due to biodegradation at the aged LNAPL- impacted sites, and (3) high electrical resistivity anomalies at the fresh or aged sites contaminated with residual products of crude oils (lubricating oils). The study results also show that the geophysical methods, as a non-invasive sounding technique, can be effectively applied to mapping hydrocarbon-contaminated zones.

Return-to-launch-site three degree of freedom analysis, constant inertial attitude during the fuel dissipation phase

NASA Technical Reports Server (NTRS)

Bown, R. L.; Winans, L. C.

1975-01-01

Results are presented of a study to show the effect of selecting a constant inertial attitude during the fuel dissipation phase of a return-to-launch-site abort. Results are also presented which show that the selection of the constant inertial attitude will affect the arrival point on the range-velocity target line. An alternate selection of the inertial attitude will provide control over the trajectory shape.

Temporal dynamics of gastropod fauna on subtidal sandy sediments of the Ensenada de Baiona (NW Iberian Peninsula)

NASA Astrophysics Data System (ADS)

Moreira, J.; Aldea, C.; Troncoso, J. S.

2010-12-01

The temporal variation of the gastropod fauna inhabiting sandy sediments of the Ensenada de Baiona (Galicia, Spain) was studied at three subtidal sites from February 1996 to February 1997 by means of quantitative sampling. A total of 5,463 individuals representing 51 gastropod species and 22 families were found. The family Pyramidellidae was the most diverse in number of species (11 species), followed by Rissoidae and Trochidae (4 species each). The dogwhelk, Nassarius reticulatus, and the rissoid snail, Rissoa parva, were the numerically dominant species at the three studied sites; those and other abundant species showed their greatest densities by the end of summer and the beginning of autumn. In general, univariate measures of the assemblage (number of species, abundance, diversity and evenness) showed variations through time; greater values were recorded between summer and autumn depending on the site. Multivariate analyses done on abundance data showed certain seasonality in the evolution of the assemblage as expected for shallow subtidal sandy sediments at temperate latitudes; those seasonal changes were mostly related to variations in abundance of numerically dominant species. Although the measured sedimentary variables did not show significant correlations with faunal univariate parameters, sediment heterogeneity due to the presence of mats of Zostera marina L. and shells of dead bivalves might explain the differences in composition of the gastropod assemblage among sampling sites.

Locations of Halide Ions in Tetragonal Lysozyme Crystals

NASA Technical Reports Server (NTRS)

Lim, Kap; Adimurthy, Ganapathi; Nadarajah, Arunan; Forsythe, Elizabeth L.; Pusey, Marc L.

1998-01-01

Anions play an important role in the crystallization of lysozyme, and are known to bind to the crystalline protein. Previous studies employing X-ray crystallography had found one chloride ion binding site in the tetragonal crystal form of the protein and four nitrate ion binding sites in the monoclinic form. Studies using other approaches have reported more chloride ion binding sites, but their locations were not known. Knowing the precise location of these anions is also useful in determining the correct electrostatic fields surrounding the protein. In the first part of this study the anion positions in the tetragonal form were determined from the difference Fourier map obtained from the lysozyme crystals grown in bromide and chloride solutions under identical conditions. The anion locations were then obtained from standard crystallographic methods and five possible anion binding sites were found in this manner. The sole chloride ion binding site found in previous studies was confirmed. The remaining four sites were new ones for tetragonal lysozyme crystals. However, three of these new sites and the previously found one corresponded to the four unique binding sites found for nitrate ions in monoclinic crystals. This suggests that most of the anion binding sites in lysozyme remain unchanged, even when different anions and different crystal forms of lysozyme are employed. It is unlikely that there are many more anions in the tetragonal lysozyme crystal structure. Assuming osmotic equilibrium it can be shown that there are at most three more anions in the crystal channels. Some of the new anion binding sites found in this study were, as expected, in pockets containing basic residues. However, some of them were near neutral, but polar, residues. Thus, the study also showed the importance of uncharged, but polar groups, on the protein surface in determining its electrostatic field. This was important for the second part of this study where the electrostatic field surrounding the protein was accurately determined. This was achieved by solving the linearized version of the Poisson-Boltzmann equation for the protein in solution. The solution was computed employing the commercial code Delphi which uses a finite difference technique. This has recently become available as a module in the general protein visualization code Insight II. Partial charges were assigned to the polar groups of lysozyme for the calculations done here. The calculations showed the complexity of the electrostatic field surrounding the protein. Although most of the region near the protein surface had a positive field strength, the active site cleft was negatively charged and this was projected a considerable distance. This might explain the occurrence of "head-to-side" interactions in the formation of lysozyme aggregates in solution. Pockets of high positive field strength were also found in the vicinity of the anion locations obtained from the crystallographic part of this study, confirming the validity of these calculations. This study clearly shows not only the importance of determining the counterion locations in protein crystals and the electrostatic fields surrounding the protein, but also the advantage of performing them together.

Characterization of the Artemisinin Binding Site for Translationally Controlled Tumor Protein (TCTP) by Bioorthogonal Click Chemistry.

PubMed

Li, Weichao; Zhou, Yiqing; Tang, Guanghui; Xiao, Youli

2016-12-21

Despite the fact that multiple artemisinin-alkylated proteins in Plasmodium falciparum have been identified in recent studies, the alkylation mechanism and accurate binding site of artemisinin-protein interaction have remained elusive. Here, we report the chemical-probe-based enrichment of the artemisinin-binding peptide and characterization of the artemisinin-binding site of P. falciparum translationally controlled tumor protein (TCTP). A peptide fragment within the N-terminal region of TCTP was enriched and found to be alkylated by an artemisinin-derived probe. MS2 fragments showed that artemisinin could alkylate multiple amino acids from Phe12 to Tyr22 of TCTP, which was supported by labeling experiments upon site-directed mutagenesis and computational modeling studies. Taken together, the "capture-and-release" strategy affords consolidated advantages previously unavailable in artemisinin-protein binding site studies, and our results deepened the understanding of the mechanism of protein alkylation via heme-activated artemisinin.

An alternative approach to characterize nonlinear site effects

USGS Publications Warehouse

Zhang, R.R.; Hartzell, S.; Liang, J.; Hu, Y.

2005-01-01

This paper examines the rationale of a method of nonstationary processing and analysis, referred to as the Hilbert-Huang transform (HHT), for its application to a recording-based approach in quantifying influences of soil nonlinearity in site response. In particular, this paper first summarizes symptoms of soil nonlinearity shown in earthquake recordings, reviews the Fourier-based approach to characterizing nonlinearity, and offers justifications for the HHT in addressing nonlinearity issues. This study then uses the HHT method to analyze synthetic data and recordings from the 1964 Niigata and 2001 Nisqually earthquakes. In doing so, the HHT-based site response is defined as the ratio of marginal Hilbert amplitude spectra, alternative to the Fourier-based response that is the ratio of Fourier amplitude spectra. With the Fourier-based approach in studies of site response as a reference, this study shows that the alternative HHT-based approach is effective in characterizing soil nonlinearity and nonlinear site response.

Spawning site selection and contingent behavior in Common Snook, Centropomus undecimalis.

PubMed

Lowerre-Barbieri, Susan; Villegas-Ríos, David; Walters, Sarah; Bickford, Joel; Cooper, Wade; Muller, Robert; Trotter, Alexis

2014-01-01

Reproductive behavior affects spatial population structure and our ability to manage for sustainability in marine and diadromous fishes. In this study, we used fishery independent capture-based sampling to evaluate where Common Snook occurred in Tampa Bay and if it changed with spawning season, and passive acoustic telemetry to assess fine scale behavior at an inlet spawning site (2007-2009). Snook concentrated in three areas during the spawning season only one of which fell within the expected spawning habitat. Although in lower numbers, they remained in these areas throughout the winter months. Acoustically-tagged snook (n = 31) showed two seasonal patterns at the spawning site: Most fish occurred during the spawning season but several fish displayed more extended residency, supporting the capture-based findings that Common Snook exhibit facultative catadromy. Spawning site selection for iteroparous, multiple-batch spawning fishes occurs at the lifetime, annual, or intra-annual temporal scales. In this study we show colonization of a new spawning site, indicating that lifetime spawning site fidelity of Common Snook is not fixed at this fine spatial scale. However, individuals did exhibit annual and intra-seasonal spawning site fidelity to this new site over the three years studied. The number of fish at the spawning site increased in June and July (peak spawning months) and on new and full lunar phases indicating within population variability in spawning and movement patterns. Intra-seasonal patterns of detection also differed significantly with sex. Common Snook exhibited divergent migration tactics and habitat use at the annual and estuarine scales, with contingents using different overwintering habitat. Migration tactics also varied at the spawning site at the intra-seasonal scale and with sex. These results have important implications for understanding how reproductive behavior affects spatio-temporal patterns of fish abundance and their resilience to disturbance events and fishing pressure.

Conserved tyrosine 182 residue in hyperthermophilic esterase EstE1 plays a critical role in stabilizing the active site.

PubMed

Truongvan, Ngoc; Chung, Hye-Shin; Jang, Sei-Heon; Lee, ChangWoo

2016-03-01

An aromatic amino acid, Tyr or Trp, located in the esterase active site wall, is highly conserved, with hyperthermophilic esterases showing preference for Tyr and lower temperature esterases showing preference for Trp. In this study, we investigated the role of Tyr(182) in the active site wall of hyperthermophilic esterase EstE1. Mutation of Tyr to Phe or Ala had a moderate effect on EstE1 thermal stability. However, a small-to-large mutation such as Tyr to His or Trp had a devastating effect on thermal stability. All mutant EstE1 enzymes showed reduced catalytic rates and enhanced substrate affinities as compared with wild-type EstE1. Hydrogen bond formation involving Tyr(182) was unimportant for maintaining EstE1 thermal stability, as the EstE1 structure is already adapted to high temperatures via increased intramolecular interactions. However, removal of hydrogen bond from Tyr(182) significantly decreased EstE1 catalytic activity, suggesting its role in stabilization of the active site. These results suggest that Tyr is preferred over a similarly sized Phe residue or bulky His or Trp residue in the active site walls of hyperthermophilic esterases for stabilizing the active site and regulating catalytic activity at high temperatures.

New insights into the interaction between pyrrolyl diketoacids and HIV-1 integrase active site and comparison with RNase H.

PubMed

Corona, Angela; di Leva, Francesco Saverio; Rigogliuso, Giuseppe; Pescatori, Luca; Madia, Valentina Noemi; Subra, Frederic; Delelis, Olivier; Esposito, Francesca; Cadeddu, Marta; Costi, Roberta; Cosconati, Sandro; Novellino, Ettore; di Santo, Roberto; Tramontano, Enzo

2016-10-01

HIV-1 integrase (IN) inhibitors are one of the most recent innovations in the treatment of HIV infection. The selection of drug resistance viral strains is however a still open issue requiring constant efforts to identify new anti-HIV-1 drugs. Pyrrolyl diketo acid (DKA) derivatives inhibit HIV-1 replication by interacting with the Mg 2+ cofactors within the HIV-1 IN active site or within the HIV-1 reverse-transcriptase associated ribonuclease H (RNase H) active site. While the interaction mode of pyrrolyl DKAs with the RNase H active site has been recently reported and substantiated by mutagenesis experiments, their interaction within the IN active site still lacks a detailed understanding. In this study, we investigated the binding mode of four pyrrolyl DKAs to the HIV-1 IN active site by molecular modeling coupled with site-directed mutagenesis studies showing that the DKA pyrrolyl scaffold primarily interacts with the IN amino residues P145, Q146 and Q148. Importantly, the tested DKAs demonstrated good effectiveness against HIV-1 Raltegravir resistant Y143A and N155H INs, thus showing an interaction pattern with relevant differences if compared with the first generation IN inhibitors. These data provide precious insights for the design of new HIV inhibitors active on clinically selected Raltegravir resistant variants. Furthermore, this study provides new structural information to modulate IN and RNase H inhibitory activities for development of dual-acting anti-HIV agents. Copyright © 2016 Elsevier B.V. All rights reserved.

Spatial distribution of soil contamination by Toxoplasma gondii in relation to cat defecation behaviour in an urban area.

PubMed

Afonso, Eve; Lemoine, Mélissa; Poulle, Marie-Lazarine; Ravat, Marie-Caroline; Romand, Stéphane; Thulliez, Philippe; Villena, Isabelle; Aubert, Dominique; Rabilloud, Muriel; Riche, Benjamin; Gilot-Fromont, Emmanuelle

2008-07-01

In urban areas, there may be a high local risk of zoonosis due to high densities of stray cat populations. In this study, soil contamination by oocysts of Toxoplasma gondii was searched for, and its spatial distribution was analysed in relation to defecation behaviour of cats living in a high-density population present in one area of Lyon (France). Sixteen defecation sites were first identified. Cats were then repeatedly fed with marked food and the marked faeces were searched for in the defecation sites. Of 260 markers, 72 were recovered from 24 different cats. Defecation sites were frequented by up to 15 individuals. Soil samples were also examined in order to detect the presence of T. gondii using real-time PCR. The entire study area was then sampled according to cat density and vegetation cover type. Only three of 55 samples were positive and all came from defecation sites. In a second series of observations, 16 defecation sites were sampled. Eight of 62 samples tested positive, originating in five defecation sites. Laboratory experiments using experimental seeding of soil showed that the inoculated dose that can be detected in 50% of assays equals 100-1000oocysts/g, depending on the strain. This study shows that high concentrations of oocysts can be detected in soil samples using molecular methods and suggests that spatial distribution of contamination areas is highly heterogeneous. Positive samples were only found in some of the defecation sites, signifying that at-risk points for human and animal infection may be very localised.

Vertical distribution and community composition of anammox bacteria in sediments of a eutrophic shallow lake.

PubMed

Qin, H; Han, C; Jin, Z; Wu, L; Deng, H; Zhu, G; Zhong, W

2018-07-01

The aim of this study was to explore the vertical distribution traits of anaerobic ammonium-oxidizing (anammox) bacterial relative abundance and community composition along the oxic/anoxic sediment profiles in a shallow lake. The Illumina Miseq-based sequencing and quantitative polymerase chain reactions were utilized to analyse relative abundance of anammox hydrazine synthase (hzsB) gene in comparison with bacterial 16S rRNA genes, anammox bacterial relative abundance (the number of anammox sequences divided by total number of sequences), community composition and diversity in sediments. The relative abundance of hzsB gene at the low-nitrogen (LN) site in the lake sediments showed that the vertical distribution of anammox bacteria increased to a peak, then decreased with increasing depth. Moreover, the relative abundance of hzsB gene at the high-nitrogen site was significantly lower than that at the LN site. Additionally, the community composition results showed that Candidatus Brocadia sp. was the dominant genus. In addition, the anammox bacterial diversity was also site specific. Redundancy analysis showed that the total N and the NH 4 + -N content might be the most important factors affecting anammox bacterial community composition in the studied sites. The results revealed the specific vertical variance of anammox bacterial distribution and community composition in oxic/anoxic sediments of a eutrophic shallow lake. This is the first study to demonstrate that anammox bacteria displayed the particular distribution in freshwater sediments, which implied a strong response to the anthropogenic eutrophication. © 2018 The Society for Applied Microbiology.

Studies on Electrical and Magnetic Properties of Mg-Substituted Nickel Ferrites

NASA Astrophysics Data System (ADS)

Chavan, Pradeep; Naik, L. R.; Belavi, P. B.; Chavan, Geeta; Ramesha, C. K.; Kotnala, R. K.

2017-01-01

The semiconducting polycrystalline ferrite materials with the general formula Ni1- x Mg x Fe2O4 were synthesized by using the solid state reaction method. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrographs, and atomic force microscopy techniques were utilized to study the structural parameters. XRD confirms the formation of single phase cubic spinel structure of the ferrites. The crystallite sizes of ferrites determined using the Debye-Scherer formula ranges from 0.963 μm to 1.069 μm. The cation distribution of ferrite shows that Mg2+ ions occupy a tetrahedral site ( A-site) and the Ni2+ ion occupy an octahedral site ( B-site) whereas Fe3+ ions occupies an octahedral as well as a tetrahedral site. The study of elastic parameters such as the longitudinal modulus, rigidity modulus, Young's modulus, bulk modulus, and Debye temperature were estimated using the FTIR technique. The decrease of direct current (DC) resistivity with increase in temperature indicates the semiconducting nature of ferrites. The dielectric constant as well as loss tangent decreases with increase in frequency, and at still higher frequencies, they are almost constant. This shows usual dielectric dispersion behavior attributed to the Maxwell-Wagner type of interfacial polarization and is in accordance with Koop's phenomenological theory. The linear increase of alternating current conductivity with increase of frequency shows the small polaron hopping type of conduction mechanism in all the ferrites. The magnetic properties such as saturation magnetization ( M s ), magnetic moment, coercivity, remnant magnetization ( M r ), and the ratio of M r /M s was estimated using the M-H loop.

Crystal structure of glucose isomerase in complex with xylitol inhibitor in one metal binding mode.

PubMed

Bae, Ji-Eun; Kim, In Jung; Nam, Ki Hyun

2017-11-04

Glucose isomerase (GI) is an intramolecular oxidoreductase that interconverts aldoses and ketoses. These characteristics are widely used in the food, detergent, and pharmaceutical industries. In order to obtain an efficient GI, identification of novel GI genes and substrate binding/inhibition have been studied. Xylitol is a well-known inhibitor of GI. In Streptomyces rubiginosus, two crystal structures have been reported for GI in complex with xylitol inhibitor. However, a structural comparison showed that xylitol can have variable conformation at the substrate binding site, e.g., a nonspecific binding mode. In this study, we report the crystal structure of S. rubiginosus GI in a complex with xylitol and glycerol. Our crystal structure showed one metal binding mode in GI, which we presumed to represent the inactive form of the GI. The metal ion was found only at the M1 site, which was involved in substrate binding, and was not present at the M2 site, which was involved in catalytic function. The O 2 and O 4 atoms of xylitol molecules contributed to the stable octahedral coordination of the metal in M1. Although there was no metal at the M2 site, no large conformational change was observed for the conserved residues coordinating M2. Our structural analysis showed that the metal at the M2 site was not important when a xylitol inhibitor was bound to the M1 site in GI. Thus, these findings provided important information for elucidation or engineering of GI functions. Copyright © 2017 Elsevier Inc. All rights reserved.

Population bottlenecks, genetic diversity and breeding ability of the three-spined stickleback (Gasterosteus aculeatus) from three polluted English Rivers.

PubMed

Santos, Eduarda M; Hamilton, Patrick B; Coe, Tobias S; Ball, Jonathan S; Cook, Alastair C; Katsiadaki, Ioanna; Tyler, Charles R

2013-10-15

Pollution is a significant environmental pressure on fish populations in both freshwater and marine environments. Populations subjected to chronic exposure to pollutants can experience impacts ranging from altered reproductive capacity to changes in population genetic structure. Few studies, however, have examined the reproductive vigor of individuals within populations inhabiting environments characterized by chronic pollution. In this study we undertook an analysis of populations of three-spined sticklebacks (Gasterosteus aculeatus) from polluted sites, to determine levels of genetic diversity, assess for evidence of historic population genetic bottlenecks and determine the reproductive competitiveness of males from these locations. The sites chosen included locations in the River Aire, the River Tees and the River Birket, English rivers that have been impacted by pollution from industrial and/or domestic effluents for over 100 years. Male reproductive competitiveness was determined via competitive breeding experiments with males and females derived from a clean water site, employing DNA microsatellites to determine parentage outcome. Populations of stickleback collected from the three historically polluted sites showed evidence of recent population bottlenecks, although only the River Aire population showed low genetic diversity. In contrast, fish collected from two relatively unpolluted sites within the River Gowy and Houghton Springs showed weak, or no evidence of such bottlenecks. Nevertheless, males derived from polluted sites were able to reproduce successfully in competition with males derived from clean water exposures, indicating that these bottlenecks have not resulted in any substantial loss of reproductive fitness in males. Copyright © 2013 Elsevier B.V. All rights reserved.

The mycobiota of the production environments of traditional Norwegian salted and dried mutton (pinnekjøtt).

PubMed

Schirmer, Bjørn C T; Wiik-Nielsen, Jannicke; Skaar, Ida

2018-07-02

In 2013, mould growth on Norwegian ready-to-sell pinnekjøtt (dried and cured lamb ribs) lead to the withdrawal of 200 tons of the product. The aim of this study was to identify the mycobiota at two Norwegian production sites and determine which species present the highest risk for reduced product quality and safety. A total of 485 samples from 2014, 2015 and 2016 were analysed for Penicillium and Aspergillus species. Both production sites showed a persistent mycobiota that remained stable over three seasons. Samples from site A were dominated by P. solitum while samples from site B were equally dominated by P. solitum, P. brevicompactum/bialowiezense and P. nordicum. The presence of P. nordicum was concentrated in one area of the production site where long-time stored hams were produced, but P. nordicum was also found sporadically in other parts of the site. Product samples taken from products with visible mould growth were at both sites dominated by P. solitum, highlighting its importance for product quality. P. nordicum was found frequently in the long-time stored hams, indicating a food safety risk of these products. However, P. nordicum was rarely isolated from pinnekjøtt. Aspergillus spp. were isolated from both sites at all samplings; however, there were no Aspergillus isolated from products, and no sites were repeatedly tested positive for identical species, indicating that Aspergillus is not a part of the persistent mycobiota, but enters the site sporadically. In conclusion, the study showed that a stable mycobiota consisting of few Penicillium species dominated the products and production environments of pinnekjøtt. Copyright © 2018 Elsevier B.V. All rights reserved.

In-situ carbon and nitrogen turnover dynamics and the role of soil functional biodiversity therein; a climate warming simulation study in Alpine ecosystems

NASA Astrophysics Data System (ADS)

Djukic, Ika

2010-05-01

Climate change affects a variety of soil properties and processes. Alpine soils take an extraordinary position in this context because of the vulnerability of mountain regions to climatic changes. We used altitudinal soil translocation to simulate the combined effects of changing climatic conditions and shifting vegetation zones in order to study short- to medium-term soil changes in the Austrian Limestone Alps. We translocated 160 soil cores from an alpine grassland site (1900 m asl) down to a sub-alpine spruce forest (1300 m asl) and a montane beech forest site (900m asl), including reference soil cores at each site to estimate artifacts arising from the method. 15N-labeled maize straw was added (1 kg/m2) to translocated and control soil cores and sampled over a period of 2 years for the analysis of δ13C and δ15N in the bulk soil and extracted phospholipid fatty acids (PLFAs). Additionally, 20 litter bags (at each of the three climatic zones) containing Fagus sylvatica or Pinus nigra litter were inserted into the soil, and decomposition was studied over a two-year period. The basic soil parameters (organic C, total N and pH) were unaffected by translocation within the observation time. Overall, decomposition of Pinus nigra litter was significantly slower compared to Fagus sylvatica, and the decomposition rate of both litter types was inversely related to elevation. The decomposition of the maize straw carbon was significantly faster in the translocated soil cores (sites at 900 and 1300 m asl) than at the original site (1900 m asl). The labelled nitrogen contents in the translocated soil cores showed just marginal differences to the soil cores at the original site. The maize straw application promptly increased the amount of bacterial and fungal PLFAs at all studied sites. Downslope translocated soil cores showed an increase in total microbial biomass and sum of bacteria. The fungal PLFA biomarker 18:2ω6,9 was slightly lower at the new (host) sites compared to the original site. The bacterial to fungal ratio of the translocated soil cores showed a rapid acclimatization to the new (host) soil conditions. Our study demonstrates that rising temperatures in Alpine ecosystems will accelerate decomposition of fresh C pools but also lead to rapid adaptation of the microbial community to the new conditions.

Does your web site draw new patients?

PubMed

Wallin, Wendy S

2009-11-01

The absence of scientific data forces orthodontists to guess at how best to design Internet sites that persuade prospective patients to call for appointments. This study was conducted to identify the Web-site factors that lead prospective patients to make appointments or, conversely, to reject a practice. Ten participants actively looking online for an orthodontist were recruited to participate. They reviewed 64 orthodontic Web sites in their geographic areas and rated their likelihood of calling each practice for an appointment. The sessions were videotaped. Analysis of participant comments, navigation patterns, and ratings suggested 25 distinguishing factors. Statistical analysis showed 10 Web-site characteristics that predict the success of an orthodontic Web site in attracting new patients.

The inhibitory activity of HL-7 and HL-10 peptide from scorpion venom (Hemiscorpius lepturus) on angiotensin converting enzyme: Kinetic and docking study.

PubMed

Setayesh-Mehr, Zahra; Asoodeh, Ahmad

2017-12-01

The hypertension is one of the highest risk factors for stroke, myocardial infarction, vascular disease and chronic kidney disease. Angiotensin converting enzyme (ACE) has an important role in the physiological regulation of cardiovascular system. ACE inhibition is a key purpose for hypertension treatment. In this study, two peptides named HL-7 with the sequence of YLYELAR (MW: 927.07Da) and HL-10 with the sequence of AFPYYGHHLG (MW: 1161.28Da) were identified from scorpion venom of H. lepturus. The inhibitory activity of HL-7 and HL-10 was examined on rabbit ACE. The inhibition mechanisms were assayed by kinetic and docking studies. The IC 50 values for ACE inhibition of HL-7 and HL-10 were 9.37µM and 17.22µM, respectively. Lineweaver-Burk plots showed that two peptides inhibited rabbit ACE with competitive manner. The molecular docking conformed experimental results and showed that the two peptides interacted with N-domain and C-domain active sites. Also, docking study revealed that the two peptides can form hydrogen and hydrophobic bonds at their binding sites. Both peptides had higher affinity to N-domain. Our results showed that HL-7 exhibited more strong interactions with amino acids at active site. It seems that HL-10 peptide could occupy more space, thereby inhibiting the substrate entrance to active site. Copyright © 2017 Elsevier Inc. All rights reserved.

Survey of atmospheric total gaseous mercury in Mexico

NASA Astrophysics Data System (ADS)

de la Rosa, D. A.; Volke-Sepúlveda, T.; Solórzano, G.; Green, C.; Tordon, R.; Beauchamp, S.

2004-09-01

While sources of gaseous mercury (natural and anthropogenic) are well known, studies on atmospheric mercury concentrations in Mexico are new. In order to assess the total gaseous mercury (TGM) levels at some characteristic Mexican sites, four locations were selected to start an exploratory survey and begin to asses the TGM behavior. This paper presents data obtained at an urban site (Mexico City), a rural site (Huejutla, Hidalgo), a coastline site (Puerto Angel, Oaxaca) and a closed mining site (Zacatecas City, Zacatecas). The highest TGM average values were found at this last site (71.82 ng m-3) together with the urban site (9.81 ng m-3). At the rural and coast line sites the lowest TGM values (1.32 and 1.46 ng m-3, respectively) were found. According to the ANOVA test, there were significant differences for the TGM values among all the studied sites, except between the coastline and the rural place. A multiple correlation test performed between TGM and some meteorological parameters showed that in sites without anthropogenic mercury sources influence (rural and coast line), the TGM levels are correlated with the temperature and relative humidity, while for the other two sites no clear correlation was found.

Effects of organizational complexity and resources on construction site risk.

PubMed

Forteza, Francisco J; Carretero-Gómez, Jose M; Sesé, Albert

2017-09-01

Our research is aimed at studying the relationship between risk level and organizational complexity and resources on constructions sites. Our general hypothesis is that site complexity increases risk, whereas more resources of the structure decrease risk. A Structural Equation Model (SEM) approach was adopted to validate our theoretical model. To develop our study, 957 building sites in Spain were visited and assessed in 2003-2009. All needed data were obtained using a specific tool developed by the authors to assess site risk, structure and resources (Construction Sites Risk Assessment Tool, or CONSRAT). This tool operationalizes the variables to fit our model, specifically, via a site risk index (SRI) and 10 organizational variables. Our random sample is composed largely of small building sites with general high levels of risk, moderate complexity, and low resources on site. The model obtained adequate fit, and results showed empirical evidence that the factors of complexity and resources can be considered predictors of site risk level. Consequently, these results can help companies, managers of construction and regulators to identify which organizational aspects should be improved to prevent risks on sites and consequently accidents. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

Ferrous Ion Sites in Angrite Pyroxenes: A Mössbauer Spectroscopy Study

NASA Astrophysics Data System (ADS)

Hoffman, E. J.

2002-03-01

Mössbauer spectra of angrites D'Orbigny and Sahara 99555 show that pyroxene ferrous ion is preominantly in the M1 site, not the M2 as for Angora dos Reis. These results are consistent with IR spectral data (Burbine et al., 2001, LPS XXXII,1857).

Personal Exposure, Behavior, and Work Site Conditions as Determinants of Blood Lead Among Bridge Painters

PubMed Central

Rodrigues, Ema G.; Virji, M. Abbas; McClean, Michael D.; Weinberg, Janice; Woskie, Susan; Pepper, Lewis D.

2009-01-01

Bridge painters are exposed to lead during several job tasks performed during the workday, such as sanding, scraping, and blasting. After the Occupational Safety and Health Administration standard was passed in 1993 to control lead exposures among construction workers including bridge painters, this study was conducted among 84 bridge painters in the New England area to determine the significant predictors of blood lead levels. Lead was measured in personal air and hand wipe samples that were collected during the 2-week study period and in blood samples that were collected at the beginning and at the end of the study period. The personal air and hand wipe data as well as personal behaviors (i.e., smoking, washing, wearing a respirator) and work site conditions were analyzed as potential determinants of blood lead levels using linear mixed effects models. Our results show that the mean air lead levels over the 2-week period were the most predictive exposure measure of blood lead levels. Other individual-level significant predictors of blood lead levels included months worked on bridge painting crews, education, and personal hygiene index. Of the site-level variables investigated, having a containment facility on site was a significant predictor of blood lead levels. Our results also indicate that hand wipe lead levels were significantly associated with higher blood lead levels at the end of the study period compared with the beginning of the study period. Similarly, smoking on site and respirator fit testing were significantly associated with higher blood lead levels at the end of the study period. This study shows that several individual-level and site-level factors are associated with blood lead levels among bridge painters, including lead exposure through inhalation and possible hand-to-mouth contact, personal behaviors such as smoking on site, respirator fit testing, and work site conditions such as the use of better containment facilities. Accordingly, reduction in blood lead levels among bridge painters can be achieved by improving these workplace practices. PMID:19953411

Site Plan & Site Section of Citrus Landscape (Showing Relationship ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Site Plan & Site Section of Citrus Landscape (Showing Relationship of Victoria Avenue to Citrus Groves) - Arlington Heights Citrus Landscape, Southwestern portion of city of Riverside, Riverside, Riverside County, CA

Stability of choice in the honey bee nest-site selection process.

PubMed

Nevai, Andrew L; Passino, Kevin M; Srinivasan, Parthasarathy

2010-03-07

We introduce a pair of compartment models for the honey bee nest-site selection process that lend themselves to analytic methods. The first model represents a swarm of bees deciding whether a site is viable, and the second characterizes its ability to select between two viable sites. We find that the one-site assessment process has two equilibrium states: a disinterested equilibrium (DE) in which the bees show no interest in the site and an interested equilibrium (IE) in which bees show interest. In analogy with epidemic models, we define basic and absolute recruitment numbers (R(0) and B(0)) as measures of the swarm's sensitivity to dancing by a single bee. If R(0) is less than one then the DE is locally stable, and if B(0) is less than one then it is globally stable. If R(0) is greater than one then the DE is unstable and the IE is stable under realistic conditions. In addition, there exists a critical site quality threshold Q(*) above which the site can attract some interest (at equilibrium) and below which it cannot. We also find the existence of a second critical site quality threshold Q(**) above which the site can attract a quorum (at equilibrium) and below which it cannot. The two-site discrimination process, in which we examine a swarm's ability to simultaneously consider two sites differing in both site quality and discovery time, has a stable DE if and only if both sites' individual basic recruitment numbers are less than one. Numerical experiments are performed to study the influences of site quality on quorum time and the outcome of competition between a lower quality site discovered first and a higher quality site discovered second. 2009 Elsevier Ltd. All rights reserved.

Assessment of the living and workplace health and safety conditions of site-resident construction workers in Tehran, Iran.

PubMed

Mohseni, Peyman Hossein; Farshad, Ali Asghar; Mirkazemi, Roksana; Orak, Rouhangiz Jamshidi

2015-01-01

The purpose of this study was to assess living and workplace safety conditions of construction workers in Tehran, Iran. This cross-sectional study was conducted among 410 construction sites in a municipal area of Tehran whose municipal building permits were issued in 2011. Data on ventilation, workplace safety and hygiene were collected by direct observation and interviews with site foremen. Noise levels were estimated from 10 sound-level-meter stations in the municipality area. Lack of ventilation in the workers' rooms was abundant. Bathrooms were unhygienic and minimum requirements such as lighting and ventilation did not exist in 80% of the cases. In nearly 50% of large construction sites, sewage and garbage disposal were inappropriate. Elevator safety was poor at all sites and no measures for fall prevention were present in over 88% of active construction sites. This study showed that the mean 24-h equivalent continuous sound level Leq was over 70 dB in 80% of the sites during weekdays. The results of this study revealed poor health and safety living and working conditions of construction workers in Tehran.

Site Plan & Site Section of Citrus Landscape (Showing Relationship ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Site Plan & Site Section of Citrus Landscape (Showing Relationship of Groves & Irrigation System to Grove Canal) - Arlington Heights Citrus Landscape, Southwestern portion of city of Riverside, Riverside, Riverside County, CA

Use of biological characteristics of common carp (Cyprinus carpio) to indicate exposure to hormonally active agents in selected Minnesota streams, 1999

USGS Publications Warehouse

Lee, Kathy E.; Blazer, Vicki; Denslow, Nancy D.; Goldstein, Robert M.; Talmage, Philip J.

2000-01-01

The presence of HAAs in selected Minnesota streams was indicated by biological characteristics in common carp. Biological characteristics used in this study identified WWTP effluent as a potential source of HAAs. Additionally, fish located at sites upstream of WWTP effluent primarily draining agricultural land show indications of HAAs, which may be the result of agricultural runoff or other sources of HAAs. There was variability among all sites and among sites within each site group. Differences among sites may be due to differences in water chemistry or fish exposure time. Natural variation in the biological characteristics may account for some of the differences observed in this study. This study and others indicate the presence of HAAs in surface water and the potential signs of endocrine disruption in resident fish populations. Detailed controlled studies could confirm the effects of particular chemicals such as pesticides or components of WWTPs on fish reproduction and population structure.

The Marburg-Münster Affective Disorders Cohort Study (MACS): A quality assurance protocol for MR neuroimaging data.

PubMed

Vogelbacher, Christoph; Möbius, Thomas W D; Sommer, Jens; Schuster, Verena; Dannlowski, Udo; Kircher, Tilo; Dempfle, Astrid; Jansen, Andreas; Bopp, Miriam H A

2018-05-15

Large, longitudinal, multi-center MR neuroimaging studies require comprehensive quality assurance (QA) protocols for assessing the general quality of the compiled data, indicating potential malfunctions in the scanning equipment, and evaluating inter-site differences that need to be accounted for in subsequent analyses. We describe the implementation of a QA protocol for functional magnet resonance imaging (fMRI) data based on the regular measurement of an MRI phantom and an extensive variety of currently published QA statistics. The protocol is implemented in the MACS (Marburg-Münster Affective Disorders Cohort Study, http://for2107.de/), a two-center research consortium studying the neurobiological foundations of affective disorders. Between February 2015 and October 2016, 1214 phantom measurements have been acquired using a standard fMRI protocol. Using 444 healthy control subjects which have been measured between 2014 and 2016 in the cohort, we investigate the extent of between-site differences in contrast to the dependence on subject-specific covariates (age and sex) for structural MRI, fMRI, and diffusion tensor imaging (DTI) data. We show that most of the presented QA statistics differ severely not only between the two scanners used for the cohort but also between experimental settings (e.g. hardware and software changes), demonstrate that some of these statistics depend on external variables (e.g. time of day, temperature), highlight their strong dependence on proper handling of the MRI phantom, and show how the use of a phantom holder may balance this dependence. Site effects, however, do not only exist for the phantom data, but also for human MRI data. Using T1-weighted structural images, we show that total intracranial (TIV), grey matter (GMV), and white matter (WMV) volumes significantly differ between the MR scanners, showing large effect sizes. Voxel-based morphometry (VBM) analyses show that these structural differences observed between scanners are most pronounced in the bilateral basal ganglia, thalamus, and posterior regions. Using DTI data, we also show that fractional anisotropy (FA) differs between sites in almost all regions assessed. When pooling data from multiple centers, our data show that it is a necessity to account not only for inter-site differences but also for hardware and software changes of the scanning equipment. Also, the strong dependence of the QA statistics on the reliable placement of the MRI phantom shows that the use of a phantom holder is recommended to reduce the variance of the QA statistics and thus to increase the probability of detecting potential scanner malfunctions. Copyright © 2018 Elsevier Inc. All rights reserved.

Unravelling the Mysteries of Slip Histories, Validating Cosmogenic 36Cl Derived Slip Rates on Normal Faults

NASA Astrophysics Data System (ADS)

Goodall, H.; Gregory, L. C.; Wedmore, L.; Roberts, G.; Shanks, R. P.; McCaffrey, K. J. W.; Amey, R.; Hooper, A. J.

2017-12-01

The cosmogenic isotope chlorine-36 (36Cl) is increasingly used as a tool to investigate normal fault slip rates over the last 10-20 thousand years. These slip histories are being used to address complex questions, including investigating slip clustering and understanding local and large scale fault interaction. Measurements are time consuming and expensive, and as a result there has been little work done validating these 36Cl derived slip histories. This study aims to investigate if the results are repeatable and therefore reliable estimates of how normal faults have been moving in the past. Our approach is to test if slip histories derived from 36Cl are the same when measured at different points along the same fault. As normal fault planes are progressively exhumed from the surface they accumulate 36Cl. Modelling these 36Cl concentrations allows estimation of a slip history. In a previous study, samples were collected from four sites on the Magnola fault in the Italian Apennines. Remodelling of the 36Cl data using a Bayesian approach shows that the sites produced disparate slip histories, which we interpret as being due to variable site geomorphology. In this study, multiple sites have been sampled along the Campo Felice fault in the central Italian Apennines. Initial results show strong agreement between the sites we have processed so far and a previous study. This indicates that if sample sites are selected taking the geomorphology into account, then 36Cl derived slip histories will be highly similar when sampled at any point along the fault. Therefore our study suggests that 36Cl derived slip histories are a consistent record of fault activity in the past.

The incidence and relevance of site-reported vs. patient-reported angina: insights from the ABSORB II randomized trial comparing Absorb everolimus-eluting bioresorbable scaffold with XIENCE everolimus-eluting metallic stent.

PubMed

Grundeken, Maik J; White, Roseann M; Hernandez, John B; Dudek, Dariusz; Cequier, Angel; Haude, Michael; van Boven, Adrianus J; Piek, Jan J; Helqvist, Steffen; Sabate, Manel; Baumbach, Andreas; Suwannasom, Pannipa; Ishibashi, Yuki; Staehr, Peter; Veldhof, Susan; Cheong, Wai-Fung; de Winter, Robbert J; Garcia-Garcia, Hector M; Wykrzykowska, Joanna J; Onuma, Yoshinobu; Serruys, Patrick W; Chevalier, Bernard

2016-04-01

In the ABSORB II trial, comparing Absorb™ bioresorbable vascular scaffold with metallic XIENCE™ everolimus-eluting stent (EES), a difference was found in site-reported new or worsening angina using adverse event (AE) reporting. However, the clinical relevance of this site-reported angina is unclear. The aim of the present study was therefore to investigate the clinical relevance of site-reported angina by evaluating its relation with cardiac endpoints, cardiovascular resource utilization (including diagnostics and treatment), positive exercise stress tolerance tests (ETTs), and Seattle Angina Questionnaire (SAQ). Site-reported new or worsening angina was captured on cardiac AE forms. There was a wide variation in the total number of days with site-reported angina (overall interquartile range 35-279 days). Patients with site-reported angina showed higher rates of cardiovascular events [including the patient-oriented composite endpoint of all deaths, all myocardial infarctions (MI), or all revascularizations (21.1 vs. 4.2%, P < 0.0001), all MIs (2.3 vs. 0%, P = 0.03), and all revascularizations (21.1 vs. 0.7%, P < 0.0001)], cardiovascular resource utilization (including stress tests, anti-anginal medication, diagnostic angiographies, and hospitalization), and positive ETTs (51.9 vs. 14.9%, P < 0.001), compared with those without site-reported angina. Furthermore, an event-based analysis of the SAQ showed that patients with ongoing angina within the recall period of 4 weeks prior to the SAQ assessment have clinically and statistically significant decrements of >14 points in SAQ scores compared with those with no reported angina. We showed that the site-reported angina through AE reporting may be clinically relevant because of their relation with cardiovascular events (mostly repeat revascularizations), cardiovascular resource utilization, ETT, and SAQ. https://clinicaltrials.gov/ct2/show/NCT01425281; Unique identifier: NCT01425281.

Identifying the Tunneling Site in Strong-Field Ionization of H_{2}^{+}.

PubMed

Liu, Kunlong; Barth, Ingo

2017-12-15

The tunneling site of the electron in a molecule exposed to a strong laser field determines the initial position of the ionizing electron and, as a result, has a large impact on the subsequent ultrafast electron dynamics on the polyatomic Coulomb potential. Here, the tunneling site of the electron of H_{2}^{+} ionized by a strong circularly polarized (CP) laser pulse is studied by numerically solving the time-dependent Schrödinger equation. We show that the electron removed from the down-field site is directly driven away by the CP field and the lateral photoelectron momentum distribution (LPMD) exhibits a Gaussian-like distribution, whereas the corresponding LPMD of the electron removed from the up-field site differs from the Gaussian shape due to the Coulomb focusing and scattering by the down-field core. Our current study presents the direct evidence clarifying a long-standing controversy over the tunneling site in H_{2}^{+} and raises the important role of the tunneling site in strong-field molecular ionization.

Analysis of the activation of acetylcholinesterase by carbon nanoparticles using a monolithic immobilized enzyme microreactor: role of the water molecules in the active site gorge.

PubMed

Ibrahim, Firas; Andre, Claire; Iutzeler, Anne; Guillaume, Yves Claude

2013-10-01

A biochromatographic system was used to study the direct effect of carbon nanoparticles (CNPs) on the acetylcholinesterase (AChE) activity. The AChE enzyme was covalently immobilized on a monolithic CIM-disk via its NH2 residues. Our results showed an increase in the AChE activity in presence of CNPs. The catalytic constant (k(cat)) was increased while the Michaelis constant (K(m)) was slightly decreased. This indicated an increase in the enzyme efficiency with increase of the substrate affinity to the active site. The thermodynamic data of the activation mechanism of the enzyme, i.e. ΔH* and ΔS*, showed no change in the substrate interaction mechanism with the anionic binding site. The increase of the enthalpy (ΔH*) and the entropy (ΔS*) with decrease in the free energy of activation (Ea) was related to structural conformation change in the active site gorge. This affected the stability of water molecules in the active site gorge and facilitated water displacement by substrate for entering to the active site of the enzyme.

Face, content, and construct validity of four, inanimate training exercises using the da Vinci ® Si surgical system configured with Single-Site ™ instrumentation.

PubMed

Jarc, Anthony M; Curet, Myriam

2015-08-01

Validated training exercises are essential tools for surgeons as they develop technical skills to use robot-assisted minimally invasive surgical systems. The purpose of this study was to show face, content, and construct validity of four, inanimate training exercises using the da Vinci (®) Si surgical system configured with Single-Site (™) instrumentation. New (N = 21) and experienced (N = 6) surgeons participated in the study. New surgeons (11 Gynecology [GYN] and 10 General Surgery [GEN]) had not completed any da Vinci Single-Site cases but may have completed multiport cases using the da Vinci system. They participated in this study prior to attending a certification course focused on da Vinci Single-Site instrumentation. Experienced surgeons (5 GYN and 1 GEN) had completed at least 25 da Vinci Single-Site cases. The surgeons completed four inanimate training exercises and then rated them with a questionnaire. Raw metrics and overall normalized scores were computed using both video recordings and kinematic data collected from the surgical system. The experienced surgeons significantly outperformed new surgeons for many raw metrics and the overall normalized scores derived from video review (p < 0.05). Only one exercise did not achieve a significant difference between new and experienced surgeons (p = 0.08) when calculating an overall normalized score using both video and advanced metrics derived from kinematic data. Both new and experienced surgeons rated the training exercises as appearing, to train and measure technical skills used during da Vinci Single-Site surgery and actually testing the technical skills used during da Vinci Single-Site surgery. In summary, the four training exercises showed face, content, and construct validity. Improved overall scores could be developed using additional metrics not included in this study. The results suggest that the training exercises could be used in an overall training curriculum aimed at developing proficiency in technical skills for surgeons new to da Vinci Single-Site instrumentation.

Crystallographic site swapping of La3+ ion in BaA'LaTeO6 (A' = Na, K, Rb) double perovskite type compounds: diffraction and photoluminescence evidence for the site swapping.

PubMed

Phatak, R; Gupta, S K; Krishnan, K; Sali, S K; Godbole, S V; Das, A

2014-02-28

Double perovskite type compounds of the formula BaA'LaTeO6 (A' = Na, K, Rb) were synthesized by solid state route and their crystal structures were determined by Rietveld analysis using powder X-ray diffraction and neutron diffraction data. Na compound crystallizes in the monoclinic system with P2₁/n space group whereas, K and Rb compounds crystallize in Fm3m space group. All the three compounds show rock salt type ordering at B site. Crystal structure analysis shows that La ion occupies A site in Na compound whereas, it occupies B site in K and Rb compounds according to the general formula of AA'BB'O6 for a double perovskite type compound. Effect of this crystallographic site swapping of the La ion was also observed in the photoluminescence study by doping Eu(3+) in La(3+) site. The large decrease in the intensity of the electric dipole ((5)D0-(7)F2) transition in the Rb compound compared to the Na compound indicates that Eu(3+) ion resides in the centrosymmetric octahedral environment in the Rb compound.

Evaluation of the Main Ceos Pseudo Calibration Sites Using Modis Brdf/albedo Products

NASA Astrophysics Data System (ADS)

Kharbouche, Said; Muller, Jan-Peter

2016-06-01

This work describes our findings about an evaluation of the stability and the consistency of twenty primary PICSs (Pseudo-Invariant Calibration Sites). We present an analysis of 13 years of 8-daily MODIS products of BRDF parameters and white-sky-albedos (WSA) over the shortwave band. This time series of WSA and BRDFs shows the variation of the "stability" varies significantly from site to site. Using a 10x10 km window size over all the sites, the change in of WSA stability is around 4% but the isotropicity, which is an important element in inter-satellite calibration, can vary from 75% to 98%. Moreover, some PICS, especially, Libya-4 which is one of the PICS which is most employed, has significant and relatively fast changes in wintertime. PICS observations of BRDF/albedo shows that the Libya-4 PICS has the best performance but it is not too far from some sites such as Libya-1 and Mali. This study also reveals that Niger-3 PICS has the longest continuous period of high stability per year, and Sudan has the most isotropic surface. These observations have important implications for the use of these sites.

Greenhouse gas emission and mitigation potential of changes in water management for two rice sites in Bangladesh

NASA Astrophysics Data System (ADS)

Begum, Khadiza; Kuhnert, Matthias; Yeluripati, Jagadeesh; Smith, Pete; Ogle, Stephen; Parton, William; Kader, Abdul; Sleutel, Steven

2017-04-01

Agriculture is one of the main contributors to greenhouse gas (GHG) emissions in Bangladesh and rice production is one of the largest sources of GHG emissions. This study considers measurements from two test sites, situated in Mymensingh (Bangladesh), to calibrate and validate the biogeochemical model DailyDayCent and estimate the mitigation potential of alternative management practices at the sites. There are two different N application treatments on the two test sites, which are on the first site a control with no N application and a mineral fertilizer application (120 kg N ha-1) and on the second site only a mineral fertilizer application (110 kg N ha-1). For mitigation, the water management is modified in a modelling approach to estimate the mitigation potential for reducing GHG emissions. The model shows partial agreement with the observations. The modifications to the water management, by changing from permanent wetting to alternate wetting, shows a decrease in GHG emissions of up to 46 % and 37 % for the two test sites, respectively. These tests enable an optimization of the management options to reduce the GHG emissions while maintaining yields.

Investigating vegetation spectral reflectance for detecting hydrocarbon pipeline leaks from multispectral data

NASA Astrophysics Data System (ADS)

Adamu, Bashir; Tansey, Kevin; Bradshaw, Michael J.

2013-10-01

The aim of this paper is to analyse spectral reflectance data from Landsat TM of vegetation that has been exposed to hydrocarbon contamination from oil spills from pipelines. The study is undertaken in an area of mangrove and swamp vegetation where the detection of an oil spill is traditionally difficult to make. We used a database of oil spill records to help identify candidate sites for spectral analysis. Extracted vegetation spectra were compared between polluted and nonpolluted sites and supervised (neural network) classification was carried out to map hydrocarbon (HC) contaminated sites from the sample areas. Initial results show that polluted sites are characterised by high reflectance in the visible (VIS) 0.4μm - 0.7μm, and a lower reflectance in the near-infrared (NIR) 0.7μm - 1.1μm. This suggests that the vegetation is in a stressed state. Samples taken from pixels surrounding polluted sites show similar spectral reflectance values to that of polluted sites suggesting possible migration of HC to the wider environment. Further work will focus on increasing the sample size and investigating the impact of an oil spill on a wider buffer zone around the spill site.

Ground state and magnetic phase transitions of the spin Lieb nanolattice: Monte Carlo simulations

NASA Astrophysics Data System (ADS)

Masrour, R.; Jabar, A.

2018-02-01

We study the ground state and magnetic properties of the spin Lieb nanolattice with three lattice sites with spins (S = 2 , σ = 1 / 2 , q = 3 / 2) using Monte Carlo simulations. The ground state phase diagrams of the Lieb nanolattice have been studied. The phase diagrams show some key features: coexistence between regions, points where six, eight and ten states can coexist. The total and partial magnetization of each sublattice is given and the corresponding magnetic susceptibility is also found. The variation of total magnetization with the exchange interaction RSq and Rσq of the Lieb nanolattice with three lattice sites with spins (S , σ , q) has been studied. Moreover, the total magnetization versus the fields Δ /JSσ of the Lieb nanolattice with three lattice sites with spins (S , σ , q) are established for several values of Rσq and Rsq. Magnetic hysteresis cycles of the Lieb nanolattice with three lattice sites with spins (S , σ , q) are found for several values of Rsq and temperature. We show that the superparamagnetism behaviour appears for a weak coupling value between S and q thus around the transition temperature.

Analysis of governmental Web sites on food safety issues: a global perspective.

PubMed

Namkung, Young; Almanza, Barbara A

2006-10-01

Despite a growing concern over food safety issues, as well as a growing dependence on the Internet as a source of information, little research has been done to examine the presence and relevance of food safety-related information on Web sites. The study reported here conducted Web site analysis in order to examine the current operational status of governmental Web sites on food safety issues. The study also evaluated Web site usability, especially information dimensionalities such as utility, currency, and relevance of content, from the perspective of the English-speaking consumer. Results showed that out of 192 World Health Organization members, 111 countries operated governmental Web sites that provide information about food safety issues. Among 171 searchable Web sites from the 111 countries, 123 Web sites (71.9 percent) were accessible, and 81 of those 123 (65.9 percent) were available in English. The majority of Web sites offered search engine tools and related links for more information, but their availability and utility was limited. In terms of content, 69.9 percent of Web sites offered information on foodborne-disease outbreaks, compared with 31.5 percent that had travel- and health-related information.

Sediment compaction and pore pressure prediction in deepwater basin of the South China Sea: Estimation from ODP and IODP drilling well data

NASA Astrophysics Data System (ADS)

Xie, Yangbing; Wu, Tuoyu; Sun, Jin; Zhang, Hanyu; Wang, Jiliang; Gao, Jinwei; Chen, Chuanxu

2018-02-01

Overpressure in deepwater basins not only causes serious soft sediment deformation, but also significantly affects the safety of drilling operations. Therefore, prediction of overpressure in sediments has become an important task in deepwater oil exploration and development. In this study, we analyze the drilling data from ODP Leg 184 Sites 1144, 1146, and 1148, and IODP Leg 349 Sites U1431, U1432, U1433, and U1435 to study the sediment compaction and controls in the northern South China Sea. Sedimentation rate, sediment content, distribution area, and buried depth are the factors that influence sediment compaction in the deepwater basin of the South China Sea. Among these factors, the sediment content is the most important. The fitted normal compacted coefficients and mudline porosity for an interval of 50 m shows disciplinary variation versus depth. The pore pressure predicted from different fitted results shows varying overpressure situations. The normal compaction trend from Site 1144 reflects the porosity variation trend in stable deposition basins in the northern South China Sea. The predicted pore pressure shows overpressure at Site 1144, which is attributed to compaction disequilibrium. Nevertheless, the mixed lithology column may influence the predicted over-pressure at Site 1148, which is responsible for the confusing result. Above all, we find that sediment compaction should serve as a proxy for pore pressure in the deepwater basin of the South China Sea.

Distribution Characteristics and Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Momoge Wetland, China

PubMed Central

Xu, Jianling; Wang, Hanxi; Sheng, Lianxi; Liu, Xuejun; Zheng, Xiaoxue

2017-01-01

The Momoge Nature Reserve is the research object of this study. Through field sampling, laboratory experiments and analysis, the contents, distribution characteristics, source identification, pollution levels and risk levels of polycyclic aromatic hydrocarbons (PAHs) in wetland soils were studied. The results show that the sum content of 16 types of PAHs (Σ16 PAH) in the wetland soil was within the range (0.029–0.4152) mg/kg. PAHs in wetland soil are primarily 2–3-rings PAHs. PAHs in the Momoge wetland soil have multiple sources: petroleum, combustion of petroleum and coal, and others, of which petroleum and the sum of combustion of petroleum and coal account for 38.0% and 59.3%, respectively. Research, using the standard index and pollution range methods, shows that the content of the PAH labelled Nap, found in the Momoge wetland soil, is excessive; some sampling sites exhibit a low level of pollution. The result of a biotoxicity assessment shows that there are two sampling sites that occasionally present an ecological toxicity hazard. The result of the organic carbon normalization process shows that an ecological risk exists only at sampling site No. 10. PMID:28106776

Patterns of multisite pain and associations with risk factors

PubMed Central

Coggon, David; Ntani, Georgia; Palmer, Keith T.; Felli, Vanda E.; Harari, Raul; Barrero, Lope H.; Felknor, Sarah A.; Gimeno, David; Cattrell, Anna; Vargas-Prada, Sergio; Bonzini, Matteo; Solidaki, Eleni; Merisalu, Eda; Habib, Rima R.; Sadeghian, Farideh; Masood Kadir, M.; Warnakulasuriya, Sudath S.P.; Matsudaira, Ko; Nyantumbu, Busisiwe; Sim, Malcolm R.; Harcombe, Helen; Cox, Ken; Marziale, Maria H.; Sarquis, Leila M.; Harari, Florencia; Freire, Rocio; Harari, Natalia; Monroy, Magda V.; Quintana, Leonardo A.; Rojas, Marianela; Salazar Vega, Eduardo J.; Harris, E. Clare; Serra, Consol; Martinez, J. Miguel; Delclos, George; Benavides, Fernando G.; Carugno, Michele; Ferrario, Marco M.; Pesatori, Angela C.; Chatzi, Leda; Bitsios, Panos; Kogevinas, Manolis; Oha, Kristel; Sirk, Tuuli; Sadeghian, Ali; Peiris-John, Roshini J.; Sathiakumar, Nalini; Wickremasinghe, A. Rajitha; Yoshimura, Noriko; Kelsall, Helen L.; Hoe, Victor C.W; Urquhart, Donna M.; Derrett, Sarah; McBride, David; Herbison, Peter; Gray, Andrew

2013-01-01

To explore definitions for multisite pain, and compare associations with risk factors for different patterns of musculoskeletal pain, we analysed cross-sectional data from the Cultural and Psychosocial Influences on Disability (CUPID) study. The study sample comprised 12,410 adults aged 20–59 years from 47 occupational groups in 18 countries. A standardised questionnaire was used to collect information about pain in the past month at each of 10 anatomical sites, and about potential risk factors. Associations with pain outcomes were assessed by Poisson regression, and characterised by prevalence rate ratios (PRRs). Extensive pain, affecting 6–10 anatomical sites, was reported much more frequently than would be expected if the occurrence of pain at each site were independent (674 participants vs 41.9 expected). In comparison with pain involving only 1–3 sites, it showed much stronger associations (relative to no pain) with risk factors such as female sex (PRR 1.6 vs 1.1), older age (PRR 2.6 vs 1.1), somatising tendency (PRR 4.6 vs 1.3), and exposure to multiple physically stressing occupational activities (PRR 5.0 vs 1.4). After adjustment for number of sites with pain, these risk factors showed no additional association with a distribution of pain that was widespread according to the frequently used American College of Rheumatology criteria. Our analysis supports the classification of pain at multiple anatomical sites simply by the number of sites affected, and suggests that extensive pain differs importantly in its associations with risk factors from pain that is limited to only a small number of anatomical sites. PMID:23727463

Dredging and contaminant exposure to tree swallows nesting on the upper Mississippi River

USGS Publications Warehouse

Custer, Thomas W.; Dummer, Paul; Custer, Christine M.; Warburton, David

2013-01-01

n 2008 and 2009, dredge material from the Mississippi River in Pool 8 south of Brownsville, Minnesota was used to construct nearby islands. Chemical analysis of sediment in 2001 and 2002 in the area to be dredged indicated detectable concentrations of organic and inorganic contaminants. Tree swallows (Tachycineta bicolor), whose diet is mainly aquatic invertebrates, were used to evaluate contaminant exposure in both the dredged and newly created habitat. Organic and inorganic contaminant data were collected from tree swallows in 2007 through 2010 at one study site near the dredging operation, a reference study site upriver from the dredging activity, one study site down river from the dredging activity, and one study site on a newly created island (2009 and 2010 only). Organic and element concentrations were at background levels in all samples. Polychlorinated biphenyl and p,p′-dichlorodiphenyldichloroethylene concentrations in tree swallow nestlings decreased at all study sites over the period 2007 to 2010 including the island study site between 2009 and 2010. Element concentrations in tree swallow livers for the non-island study sites did not show a trend among years in relation to the dredging. Selenium concentrations at the newly created island were higher and cadmium concentrations were lower in 2010 than 2009. Hatching success of eggs in successful nests was not associated with dredging activities.

Astronomical Extinction Over The ELT Moroccan Sites From Aerosol Satellite Data

NASA Astrophysics Data System (ADS)

Siher, E. A.; Benkhaldoun, Z.; Bounhir, A.

2006-08-01

Two Moroccan sites are selected to be characterized for the ELT telescopes. These sites are in the Atlas, between Oukaimeden (where is the national observatory) and The Canaries Islands. For a preliminary study, we will use the TOMS/Nimbus7 aerosol index (AI), threshold 0.7, to extract the astronomical extinction (AE), threshold 0.2 mag/airmass. In fact, on the one hand, one previously work showed the link between these parameters over the Canaries Islands (ORM Observatory). On the other hand, many studies proposed the dust characterization for the future extremely large telescope for a mandatory qualification.

Identification of adsorption sites in Cu-BTC by experimentation and molecular simulation.

PubMed

García-Pérez, Elena; Gascón, Jorge; Morales-Flórez, Víctor; Castillo, Juan Manuel; Kapteijn, Freek; Calero, Sofía

2009-02-03

The adsorption of several quadrupolar and nonpolar gases on the Metal Organic Framework Cu-BTC has been studied by combining experimental measurements and Monte Carlo simulations. Four main adsorption sites for this structure have been identified: site I close to the copper atoms, site I' in the bigger cavities, site II located in the small octahedral cages, and site III at the windows of the four open faces of the octahedral cage. Our simulations identify the octahedral cages (sites II and III) and the big cages (site I') as the preferred positions for adsorption, while site I, near the copper atoms, remains empty over the entire range of pressures analyzed due to its reduced accessibility. The occupation of the different sites for ethane and propane in Cu-BTC proceeds similarly as for methane, and shows small differences for O2 and N2 that can be attributed to the quadrupole moment of these molecules. Site II is filled predominantly for methane (the nonpolar molecule), whereas for N2, the occupation of II and I' can be considered almost equivalent. The molecular sitting for O2 shows an intermediate behavior between those observed for methane and for N2. The differences between simulated and experimental data at elevated temperatures for propane are tentatively attributed to a reversible change in the lattice parameters of Cu-BTC by dehydration and by temperature, blocking the accessibility to site III and reducing that to site I'. Adsorption parameters of the investigated molecules have been determined from the simulations.

Streambed adjustment and channel widening in eastern Nebraska

USGS Publications Warehouse

Rus, David L.; Dietsch, Benjamin J.; Simon, Andrew

2003-01-01

In eastern Nebraska, stream straightening and dredging efforts since the 1890s have disturbed the natural equilibrium of stream channels and have led to streambed adjustment by degradation and subsequent channel widening. This report describes a study to evaluate the effect these disturbances have had on stream channels in eastern Nebraska. Two sets of survey data were collected approximately 2 years apart during 1996-99 at 151 primary sites. Additionally, historical streambed-elevation data (dating back to the 1890s) were compiled from several sources for the primary sites and 45 supplemental sites, and relevant disturbances were identified for each of eight basin groupings. Streambed-elevation data sets were used to estimate the amount of change to the streambed at the sites over the time period of the data. Recent channel widening was documented for 73 of the primary sites by comparing the two survey sets. The majority of observed streambed-gradation responses appear to be related to the various straightening efforts and to the effects of grade-control structures in the study area. Channel responses were complicated by the presence of multiple disturbances. However, in many cases, the streambed-elevation data sets provide a reliable representation of the past streambed gradation, with some sites showing 6 to 7 meters of degradation since they were straightened. Many sites that had been straightened showed considerable degradation following the disturbance. This indicates that eastern Nebraska stream channels can regain equilibrium mainly through the slope adjustment process of head-ward-progressing degradation. Bank failures were documented at sites in all eight of the basin groupings analyzed, and widening rates were computed at 64 of 73 sites. Observed bank widening in the Big Blue River Basin, a relatively unstraightened basin, indicates that other disturbances besides stream-channel straightening may be causing channel responses in the basin and possibly in the entire study area.

Regeneration complexities of Pinus gerardiana in dry temperate forests of Indian Himalaya.

PubMed

Kumar, Raj; Shamet, G S; Mehta, Harsh; Alam, N M; Kaushal, Rajesh; Chaturvedi, O P; Sharma, Navneet; Khaki, B A; Gupta, Dinesh

2016-04-01

Pinus gerardiana is considered an important species in dry temperate forests of North-Western Indian Himalaya because of its influence on ecological processes and economic dependence of local people in the region. But, large numbers of biotic and abiotic factors have affected P. gerardiana in these forests; hence, there is a crucial need to understand the regeneration dynamics of this tree species. The present investigation was conducted in P. gerardiana forests to understand vegetation pattern and regeneration processes on different sites in the region. Statistical analysis was performed to know variability in growing stock and regeneration on sample plots, while correlation coefficients and regression models were developed to find the relationship between regeneration and site factors. The vegetation study showed dominance of P. gerardiana, which is followed by Cedrus deodara, Pinus wallichiana and Quercus ilex in the region. The growing stock of P. gerardiana showed steep increasing and then steadily declining trend from lower to higher diameter class. The distribution of seedling, sapling, pole and trees was not uniform at different sites and less number of plots in each site were observed to have effective conditions for continuous regeneration, but mostly showed extremely limited regeneration. Regeneration success ranging from 8.44 to 15.93 % was recorded in different sites of the region, which suggests that in different sites regeneration success is influenced by collection of cone for extracting seed, grazing/browsing and physico-chemical properties of soil. Regeneration success showed significant correlation and relationship with most of abiotic and biotic factors. The regeneration success is lower than the requirement of sustainable forest, but varies widely among sites in dry temperate forests of Himalaya. More forest surveys are required to understand the conditions necessary for greater success of P. gerardiana in the region.

Structural Explanation for Allolactose (lac Operon Inducer) Synthesis by lacZ β-Galactosidase and the Evolutionary Relationship between Allolactose Synthesis and the lac Repressor

PubMed Central

Wheatley, Robert W.; Lo, Summie; Jancewicz, Larisa J.; Dugdale, Megan L.; Huber, Reuben E.

2013-01-01

β-Galactosidase (lacZ) has bifunctional activity. It hydrolyzes lactose to galactose and glucose and catalyzes the intramolecular isomerization of lactose to allolactose, the lac operon inducer. β-Galactosidase promotes the isomerization by means of an acceptor site that binds glucose after its cleavage from lactose and thus delays its exit from the site. However, because of its relatively low affinity for glucose, details of this site have remained elusive. We present structural data mapping the glucose site based on a substituted enzyme (G794A-β-galactosidase) that traps allolactose. Various lines of evidence indicate that the glucose of the trapped allolactose is in the acceptor position. The evidence includes structures with Bis-Tris (2,2-bis(hydroxymethyl)-2,2′,2″-nitrilotriethanol) and l-ribose in the site and kinetic binding studies with substituted β-galactosidases. The site is composed of Asn-102, His-418, Lys-517, Ser-796, Glu-797, and Trp-999. Ser-796 and Glu-797 are part of a loop (residues 795–803) that closes over the active site. This loop appears essential for the bifunctional nature of the enzyme because it helps form the glucose binding site. In addition, because the loop is mobile, glucose binding is transient, allowing the release of some glucose. Bioinformatics studies showed that the residues important for interacting with glucose are only conserved in a subset of related enzymes. Thus, intramolecular isomerization is not a universal feature of β-galactosidases. Genomic analyses indicated that lac repressors were co-selected only within the conserved subset. This shows that the glucose binding site of β-galactosidase played an important role in lac operon evolution. PMID:23486479

Comparative analysis and molecular characterization of a gene BANF1 encoded a DNA-binding protein during mitosis from the Giant Panda and Black Bear.

PubMed

Zeng, Yichun; Hou, Yi-Ling; Ding, Xiang; Hou, Wan-Ru; Li, Jian

2014-01-01

Barrier to autointegration factor 1 (BANF1) is a DNA-binding protein found in the nucleus and cytoplasm of eukaryotic cells that functions to establish nuclear architecture during mitosis. The cDNA and the genomic sequence of BANF1 were cloned from the Giant Panda (Ailuropoda melanoleuca) and Black Bear (Ursus thibetanus mupinensis) using RT-PCR technology and Touchdown-PCR, respectively. The cDNA of the BANF1 cloned from Giant Panda and Black Bear is 297 bp in size, containing an open reading frame of 270 bp encoding 89 amino acids. The length of the genomic sequence from Giant Panda is 521 bp, from Black Bear is 536 bp, which were found both to possess 2 exons. Alignment analysis indicated that the nucleotide sequence and the deduced amino acid sequence are highly conserved to some mammalian species studied. Topology prediction showed there is one Protein kinase C phosphorylation site, one Casein kinase II phosphorylation site, one Tyrosine kinase phosphorylation site, one N-myristoylation site, and one Amidation site in the BANF1 protein of the Giant Panda, and there is one Protein kinase C phosphorylation site, one Tyrosine kinase phosphorylation site, one N-myristoylation site, and one Amidation site in the BANF1 protein of the Black Bear. The BANF1 gene can be readily expressed in E. coli. Results showed that the protein BANF1 fusion with the N-terminally His-tagged form gave rise to the accumulation of an expected 14 kD polypeptide that formed inclusion bodies. The expression products obtained could be used to purify the proteins and study their function further.

Old-field plant succession on the Pajarito Plateau

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foxx, T.; Mullen, M.; Salisbury, M.

Eight fallow historic fields of the ponderosa pine and pinon-juniper cover types were surveyed to determine species composition and distribution. The purpose of the study was to understand plant succession on old fields as related to mechanically manipulated sites such as material disposal areas (MDAs). Additionally, the authors wanted a listing of species on disturbed lands of the Pajarito Plateau to aide in the reclamation planning of MDAs using native species. They also wanted to determine if any species could be used as an indicator of disturbance. The eight historic fields were all within Los Alamos County, New Mexico, andmore » had been abandoned in 1943. Two sites were within the boundaries of Los Alamos National Laboratory and were studied both in 1982 and 1993. The study provides a description of each of the field sites, historic information about the homesteads from patent applications, a photographic record of some of the sites, and a listing of species found within each field. The study showed that there were 78 different plant species found on disturbed sites. Of these 78 species, 23 were found to be dominant on one or more of the MDAs or old fields. Although, the disturbance history of each site is imperfectly known, the study does provide an indication of successional processes within disturbed sites of the Pajarito Plateau. Additionally, it provides a listing of species that will invade disturbed sites, species that may be used in site reclamation.« less

Contrasting physiological responses of two co-occurring eucalypts to seasonal drought at restored bauxite mine sites.

PubMed

Szota, Christopher; Farrell, Claire; Koch, John M; Lambers, Hans; Veneklaas, Erik J

2011-10-01

This study describes the physiological response of two co-occurring tree species (Eucalyptus marginata and Corymbia calophylla) to seasonal drought at low- and high-quality restored bauxite mine sites in south-western Australia. Seasonal changes in photosynthesis (A), stomatal conductance (g(s)), leaf water potential (ψ), leaf osmotic potential (ψ), leaf relative water content (RWC) and pressure-volume analysis were captured over an 18-month field study to (i) determine the nature and severity of physiological stress in relation to site quality and (ii) identify any physiological differences between the two species. Root system restriction at the low-quality site reduced maximum rates of gas exchange (g(s) and A) and increased water stress (midday ψ and daily RWC) in both species during drought. Both species showed high stomatal sensitivity during drought; however, E. marginata demonstrated a higher dehydration tolerance where ψ and RWC fell to -3.2 MPa and 73% compared with -2.4 MPa and 80% for C. calophylla. Corymbia calophylla showed lower g(s) and higher ψ and RWC during drought, indicating higher drought tolerance. Pressure-volume curves showed that cell-wall elasticity of E. marginata leaves increased in response to drought, while C. calophylla leaves showed lower osmotic potential at zero turgor in summer than in winter, indicating osmotic adjustment. Both species are clearly able to tolerate seasonal drought at hostile sites; however, by C. calophylla closing stomata earlier in the drought cycle, maintaining a higher water status during drought and having the additional mechanism of osmotic adjustment, it may have a greater capacity to survive extended periods of drought.

Exploring ozone pollution in Chengdu, southwestern China: A case study from radical chemistry to O3-VOC-NOx sensitivity.

PubMed

Tan, Zhaofeng; Lu, Keding; Jiang, Meiqing; Su, Rong; Dong, Huabin; Zeng, Limin; Xie, Shaodong; Tan, Qinwen; Zhang, Yuanhang

2018-09-15

We present the in-situ measurements in Chengdu, a major city in south west of China, in September 2016. The concentrations of ozone and its precursor were measured at four sites. Although the campaign was conducted in early autumn, up to 100 ppbv (parts per billion by volume) daily maximum ozone was often observed at all sites. The observed ozone concentrations showed good agreement at all sites, which implied that ozone pollution is a regional issue in Chengdu. To better understand the ozone formation in Chengdu, an observation based model is used in this study to calculate the RO x radical concentrations (RO x  = OH + HO 2  + RO 2 ) and ozone production rate (P(O 3 )). The model predicts OH daily maximum is in the range of 4-8 × 10 6  molecules cm -3 , and HO 2 and RO 2 are in the range of 3-6 × 10 8  molecules cm -3 . The modelled radical concentrations show a distinct difference between ozone pollution and attainment period. The relative incremental reactivity (RIR) results demonstrate that anthropogenic VOCs reduction is the most efficient way to mitigate ozone pollution at all sites, of which alkenes dominate >50% of the ozone production. Empirical kinetic modelling approach shows that three out of four sites are under the VOC-limited regime, while Pengzhou is in a transition regime due to the local petrochemical industry. The ozone budget analysis showed that the local ozone production driven by the photochemical process is important to the accumulation of ozone concentrations. Copyright © 2018 Elsevier B.V. All rights reserved.

Relationships between diatoms and tidal environments in Oregon and Washington, USA

USGS Publications Warehouse

Sawai, Yuki; Horton, Benjamin P.; Kemp, Andrew C.; Hawkes, Andrea D.; Nagumo, Tamostsu; Nelson, Alan R.

2016-01-01

A new regional dataset comprising 425 intertidal diatom taxa from 175 samples from 11 ecologically diverse Oregon and Washington estuaries illustrates the importance of compiling a large modern dataset from a range of sites. Cluster analyses and detrended correspondence analysis of the diatom assemblages identify distinct vertical zones within supratidal, intertidal and subtidal environments at six of the 11 study sites, but the abundance of some of the most common species varies widely among and within sites. Canonical correspondence analysis of the regional dataset shows relationships between diatom species and tidal exposure, salinity and substratum (grain size and organic content). Correspondence analyses of local datasets show higher values of explained variation than the analysis of the combined regional dataset. Our results emphasize that studies of the autecology of diatom species require many samples from a range of modern environments to adequately characterize species–environment relationships.

Water-quality data for the Clark Fork and selected tributaries from Deer Lodge to Milltown, Montana, March 1985 through June 1986

USGS Publications Warehouse

Lambing, J.H.

1987-01-01

A sampling program was conducted at six stream sites. The purpose of the study was to collect baseline data on concentrations of suspended sediment and selected trace metals in streamflow. Included in this report are tables of daily data for mean streamflow, suspended sediment concentration, and suspended sediment discharge at two streamflow gaging stations on the Clark Fork; periodic data for instantaneous streamflow, onsite water quality, and trace metal and suspended sediment concentrations in the Clark Fork and tributaries; and summary statistics for all the water quality data. Also included are graphs for each site showing median concentrations of trace metals, relationship of concentrations of trace metals to suspended sediment, and median concentrations of trace metals in suspended sediments. Hydrographs for two sites on the main stem show daily mean streamflow, suspended sediment concentration, and suspended sediment discharge for the period of study. (Author 's abstract)

Detection, breakpoint identification and detailed characterisation of a CNV at the FRA16D site using SNP assays.

PubMed

Winchester, L; Newbury, D F; Monaco, A P; Ragoussis, J

2008-01-01

Copy Number Variants (CNV) and other submicroscopic structural changes are now recognised to be widespread across the human genome. We show that SNP data generated for association study can be utilised for the identification of deletion CNVs. During analysis of data for an SNP association study for Specific Language Impairment (SLI) a deletion was identified. SLI adversely affects the language development of children in the absence of any obvious cause. Previous studies have found linkage to a region on chromosome 16. The deletion was located in a known fragile site FRA16D in intron 5-6 of the WWOX gene (also known as FOR). Changes in the FRA16D site have been previously linked to cancer and are often characterised in cell lines. A long-range PCR assay was used to confirm the existence of the deletion. We also show the breakpoint identification and large-scale characterisation of this CNV in a normal human sample set. Copyright 2009 S. Karger AG, Basel.

Performance Evaluation and Community Application of Low-Cost Sensors for Ozone and Nitrogen Dioxide.

PubMed

Duvall, Rachelle M; Long, Russell W; Beaver, Melinda R; Kronmiller, Keith G; Wheeler, Michael L; Szykman, James J

2016-10-13

This study reports on the performance of electrochemical-based low-cost sensors and their use in a community application. CairClip sensors were collocated with federal reference and equivalent methods and operated in a network of sites by citizen scientists (community members) in Houston, Texas and Denver, Colorado, under the umbrella of the NASA-led DISCOVER-AQ Earth Venture Mission. Measurements were focused on ozone (O₃) and nitrogen dioxide (NO₂). The performance evaluation showed that the CairClip O₃/NO₂ sensor provided a consistent measurement response to that of reference monitors (r² = 0.79 in Houston; r² = 0.72 in Denver) whereas the CairClip NO₂ sensor measurements showed no agreement to reference measurements. The CairClip O₃/NO₂ sensor data from the citizen science sites compared favorably to measurements at nearby reference monitoring sites. This study provides important information on data quality from low-cost sensor technologies and is one of few studies that reports sensor data collected directly by citizen scientists.

Magnetostratigraphy of reef limestones -a case study in Ryukyu Group, Okinawa, Japan-

NASA Astrophysics Data System (ADS)

Anai, C.; Shibuya, H.; Mochizuki, N.

2017-12-01

The Ryukyu Group in Ryukyu islands consists of reef limestones of Pleistocene in age, and records regression-transgression cycles of the age. It has great importance for providing the precise sea level changes around Middle-Pleistocene climate transition from 40kyr cycle to 100kyr. In order to assign a geochronological marker in the age of the transition, we investigate the magnetostratigraphical studies of the Ryukyu Group in Miyakojima island. Paleomagnetic samples were collected at 20 sites from all of 5 sequence-stratigraphic units appeared in Miyakojima island (MY-Unit 1 to 5 in ascending order). The conventional thermal demagnetization procedure provides reliable polarity only in 7 sites. For remaining 13 sites, we applied a novel technique of reductive chemical demagnetization (RCD) in addition to the conventional alternating field demagnetization. This hybrid technique successfully erased the overprinting magnetic components and unveiled the primary component. Paleomagnetic directions of 20 sites show that the studied sequence records a polarity transition from reversed to normal, and the transition is at the lowest part of the MY-Unit 4. Previous calcareous nannofossil studies show that the reversal corresponds to the Matuyama-Brunhes boundary. It enables us to correlate the Ryukyu limestones with the timing of the climate transition.

Productivity benefits of warming at regional scale could be offset by detrimental impacts on site level hydrology.

PubMed

Zeng, Qing; Zhang, Yamian; Wen, Li; Li, Zhaxijie; Duo, Hairui; Lei, Guangchun

2017-11-09

Climate change affects the distribution and persistence of wildlife. Broad scale studies have demonstrated that climate change shifts the geographic ranges and phenology of species. These findings are influential for making high level strategies but not practical enough to guide site specific management. In this study, we explored the environment factors affecting the population of Bar-headed Goose in the key breeding site of Qinghai using generalized additive mixed model (GAMM). Our results showed that 1) there were significant increasing trends in climate variables and river flows to the Qinghai Lake; 2) NDVI in the sites decreased significantly despite the regional positive trend induced by the warmer and wetter climate; 3) NDVI at site scale was negatively correlated to lake water level; and 4) the abundance of Bar-headed Goose decreased significantly at all sites. While the abundance was positively related to NDVI at breeding sites, the GAMM revealed an opposite relationship at foraging areas. Our findings demonstrated the multi-facet effects of climate change on population dynamics; and the effect at global/regional scale could be complicated by site level factors.

Restoration of areas degraded by alluvial sand mining: use of soil microbiological activity and plant biomass growth to assess evolution of restored riparian vegetation.

PubMed

Venson, Graziela R; Marenzi, Rosemeri C; Almeida, Tito César M; Deschamps-Schmidt, Alexandre; Testolin, Renan C; Rörig, Leonardo R; Radetski, Claudemir M

2017-03-01

River or alluvial sand mining is causing a variety of environmental problems in the Itajaí-açú river basin in Santa Catarina State (south of Brazil). When this type of commercial activity degrades areas around rivers, environmental restoration programs need to be executed. In this context, the aim of this study was to assess the evolution of a restored riparian forest based on data on the soil microbial activity and plant biomass growth. A reference site and three sites with soil degradation were studied over a 3-year period. Five campaigns were performed to determine the hydrolysis of the soil enzyme fluorescein diacetate (FDA), and the biomass productivity was determined at the end of the studied period. The variation in the enzyme activity for the different campaigns at each site was low, but this parameter did differ significantly according to the site. Well-managed sites showed the highest biomass productivity, and this, in turn, showed a strong positive correlation with soil enzyme activity. In conclusion, soil enzyme activity could form the basis for monitoring and the early prediction of the success of vegetal restoration programs, since responses at the higher level of biological organization take longer, inhibiting the assessment of the project within an acceptable time frame.

Active-site copper reduction promotes substrate binding of fungal lytic polysaccharide monooxygenase and reduces stability.

PubMed

Kracher, Daniel; Andlar, Martina; Furtmüller, Paul G; Ludwig, Roland

2018-02-02

Lytic polysaccharide monooxygenases (LPMOs) are a class of copper-containing enzymes that oxidatively degrade insoluble plant polysaccharides and soluble oligosaccharides. Upon reductive activation, they cleave the substrate and promote biomass degradation by hydrolytic enzymes. In this study, we employed LPMO9C from Neurospora crassa , which is active toward cellulose and soluble β-glucans, to study the enzyme-substrate interaction and thermal stability. Binding studies showed that the reduction of the mononuclear active-site copper by ascorbic acid increased the affinity and the maximum binding capacity of LPMO for cellulose. The reduced redox state of the active-site copper and not the subsequent formation of the activated oxygen species increased the affinity toward cellulose. The lower affinity of oxidized LPMO could support its desorption after catalysis and allow hydrolases to access the cleavage site. It also suggests that the copper reduction is not necessarily performed in the substrate-bound state of LPMO. Differential scanning fluorimetry showed a stabilizing effect of the substrates cellulose and xyloglucan on the apparent transition midpoint temperature of the reduced, catalytically active enzyme. Oxidative auto-inactivation and destabilization were observed in the absence of a suitable substrate. Our data reveal the determinants of LPMO stability under turnover and non-turnover conditions and indicate that the reduction of the active-site copper initiates substrate binding. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Effect of monochloramine treatment on colonization of a hospital water distribution system by Legionella spp.: a 1 year experience study.

PubMed

Mancini, Benedetta; Scurti, Maria; Dormi, Ada; Grottola, Antonella; Zanotti, Andrea; Cristino, Sandra

2015-04-07

Contamination of hot water distribution systems by Legionella represents a great challenge due to difficulties associated with inactivating microorganisms, preserving the water characteristics. The aim of this study was to examine over the course of 1 year in 11 fixed sites, the impact of monochloramine disinfection on Legionella, heterotrophic bacteria (36 °C), Pseudomonas aeruginosa contamination, and chemical parameters of a plumbing system in an Italian hospital. Three days after installation (T0), in the presence of monochloramine concentration between 1.5 and 2 mg/L, 10/11 sites (91%) were contaminated by L. pneumophila serogroups 3 and 10. After these results, the disinfectant dosage was increased to between 6 and 10 mg/L, reducing the level of Legionella by three logarithmic unit by 2 months postinstallation (T2) until 6 months later (T3). One year later (T4), there was a significant reduction (p = 0.0002) at 8/11 (73%) sites. Our data showed also a significant reduction of heterotrophic bacteria (36 °C) in 6/11 (55%) sites at T4 (p = 0.0004), by contrast the contamination of P. aeruginosa found at T0 in two sites persisted up until T4. The results of the present study show that monochloramine is a promising disinfectant that can prevent Legionella contamination of hospital water supplies.

Seasonal variations in biomass and species composition of seaweeds along the northern coasts of Persian Gulf (Bushehr Province)

NASA Astrophysics Data System (ADS)

Dadolahi-Sohrab, A.; Garavand-Karimi, M.; Riahi, H.; Pashazanoosi, H.

2012-02-01

This study was carried out to evaluate the seasonal variations of seaweed biomass and species composition at six different sites along the coastal areas in Bushehr Province. Sampling depths varied among sites, from 0.3 to 2.0 m below mean sea level. A total of 37 (i.e., 10 Chlorophyta, 12 Phaeophyta and 15 Rhodophyta) seaweed species were collected. Studies were conducted for quantifying the seaweeds during four seasons from October 2008 until July 2009. During present research, Ulva intestinalis and Cladophora nitellopsis of green, Polycladia myrica, Sirophysalia trinodis and Sargassum angustifolium of brown and Gracilaria canaliculata and Hypnea cervicornis of red seaweeds showed highest biomass in coastal areas of Bushehr Province. The Cheney`s ratio of 2.1 indicated a temperate algal flora to this area. All sites exhibited more than 50% similarity of algal species, indicating a relatively homogenous algal distribution. Total biomass showed the highest value of 3280.7 ± 537.8 g dry wt m - 2 during summer and lowest value of 856.9 ± 92.0 g dry wt m - 2 during winter. During this study, the highest and lowest seaweed biomass were recorded on the site 2 (2473.7 ± 311.0 g dry wt m - 2) and site 5 (856.7 ± 96.8 g dry wt m - 2), respectively.

Molecular dynamics explorations of active site structure in designed and evolved enzymes.

PubMed

Osuna, Sílvia; Jiménez-Osés, Gonzalo; Noey, Elizabeth L; Houk, K N

2015-04-21

This Account describes the use of molecular dynamics (MD) simulations to reveal how mutations alter the structure and organization of enzyme active sites. As proposed by Pauling about 70 years ago and elaborated by many others since then, biocatalysis is efficient when functional groups in the active site of an enzyme are in optimal positions for transition state stabilization. Changes in mechanism and covalent interactions are often critical parts of enzyme catalysis. We describe our explorations of the dynamical preorganization of active sites using MD, studying the fluctuations between active and inactive conformations normally concealed to static crystallography. MD shows how the various arrangements of active site residues influence the free energy of the transition state and relates the populations of the catalytic conformational ensemble to the enzyme activity. This Account is organized around three case studies from our laboratory. We first describe the importance of dynamics in evaluating a series of computationally designed and experimentally evolved enzymes for the Kemp elimination, a popular subject in the enzyme design field. We find that the dynamics of the active site is influenced not only by the original sequence design and subsequent mutations but also by the nature of the ligand present in the active site. In the second example, we show how microsecond MD has been used to uncover the role of remote mutations in the active site dynamics and catalysis of a transesterase, LovD. This enzyme was evolved by Tang at UCLA and Codexis, Inc., and is a useful commercial catalyst for the production of the drug simvastatin. X-ray analysis of inactive and active mutants did not reveal differences in the active sites, but relatively long time scale MD in solution showed that the active site of the wild-type enzyme preorganizes only upon binding of the acyl carrier protein (ACP) that delivers the natural acyl group to the active site. In the absence of bound ACP, a noncatalytic arrangement of the catalytic triad is dominant. Unnatural truncated substrates are inactive because of the lack of protein-protein interactions provided by the ACP. Directed evolution is able to gradually restore the catalytic organization of the active site by motion of the protein backbone that alters the active site geometry. In the third case, we demonstrate the key role of MD in combination with crystallography to identify the origins of substrate-dependent stereoselectivities in a number of Codexis-engineered ketoreductases, one of which is used commercially for the production of the antibiotic sulopenem. Here, mutations alter the shape of the active site as well as the accessibility of water to different regions of it. Each of these examples reveals something different about how mutations can influence enzyme activity and shows that directed evolution, like natural evolution, can increase catalytic activity in a variety of remarkable and often subtle ways.

Systematic data ingratiation of clinical trial recruitment locations for geographic-based query and visualization

PubMed Central

Luo, Jake; Chen, Weiheng; Wu, Min; Weng, Chunhua

2018-01-01

Background Prior studies of clinical trial planning indicate that it is crucial to search and screen recruitment sites before starting to enroll participants. However, currently there is no systematic method developed to support clinical investigators to search candidate recruitment sites according to their interested clinical trial factors. Objective In this study, we aim at developing a new approach to integrating the location data of over one million heterogeneous recruitment sites that are stored in clinical trial documents. The integrated recruitment location data can be searched and visualized using a map-based information retrieval method. The method enables systematic search and analysis of recruitment sites across a large amount of clinical trials. Methods The location data of more than 1.4 million recruitment sites of over 183,000 clinical trials was normalized and integrated using a geocoding method. The integrated data can be used to support geographic information retrieval of recruitment sites. Additionally, the information of over 6000 clinical trial target disease conditions and close to 4000 interventions was also integrated into the system and linked to the recruitment locations. Such data integration enabled the construction of a novel map-based query system. The system will allow clinical investigators to search and visualize candidate recruitment sites for clinical trials based on target conditions and interventions. Results The evaluation results showed that the coverage of the geographic location mapping for the 1.4 million recruitment sites was 99.8%. The evaluation of 200 randomly retrieved recruitment sites showed that the correctness of geographic information mapping was 96.5%. The recruitment intensities of the top 30 countries were also retrieved and analyzed. The data analysis results indicated that the recruitment intensity varied significantly across different countries and geographic areas. Conclusion This study contributed a new data processing framework to extract and integrate the location data of heterogeneous recruitment sites from clinical trial documents. The developed system can support effective retrieval and analysis of potential recruitment sites using target clinical trial factors. PMID:29132636

Systematic data ingratiation of clinical trial recruitment locations for geographic-based query and visualization.

PubMed

Luo, Jake; Chen, Weiheng; Wu, Min; Weng, Chunhua

2017-12-01

Prior studies of clinical trial planning indicate that it is crucial to search and screen recruitment sites before starting to enroll participants. However, currently there is no systematic method developed to support clinical investigators to search candidate recruitment sites according to their interested clinical trial factors. In this study, we aim at developing a new approach to integrating the location data of over one million heterogeneous recruitment sites that are stored in clinical trial documents. The integrated recruitment location data can be searched and visualized using a map-based information retrieval method. The method enables systematic search and analysis of recruitment sites across a large amount of clinical trials. The location data of more than 1.4 million recruitment sites of over 183,000 clinical trials was normalized and integrated using a geocoding method. The integrated data can be used to support geographic information retrieval of recruitment sites. Additionally, the information of over 6000 clinical trial target disease conditions and close to 4000 interventions was also integrated into the system and linked to the recruitment locations. Such data integration enabled the construction of a novel map-based query system. The system will allow clinical investigators to search and visualize candidate recruitment sites for clinical trials based on target conditions and interventions. The evaluation results showed that the coverage of the geographic location mapping for the 1.4 million recruitment sites was 99.8%. The evaluation of 200 randomly retrieved recruitment sites showed that the correctness of geographic information mapping was 96.5%. The recruitment intensities of the top 30 countries were also retrieved and analyzed. The data analysis results indicated that the recruitment intensity varied significantly across different countries and geographic areas. This study contributed a new data processing framework to extract and integrate the location data of heterogeneous recruitment sites from clinical trial documents. The developed system can support effective retrieval and analysis of potential recruitment sites using target clinical trial factors. Copyright © 2017 Elsevier B.V. All rights reserved.

The nature of the exchange coupling between high-spin Fe(III) heme o3 and CuBII in Escherichia coli quinol oxidase, cytochrome bo3: MCD and EPR studies.

PubMed

Cheesman, Myles R; Oganesyan, Vasily S; Watmough, Nicholas J; Butler, Clive S; Thomson, Andrew J

2004-04-07

Fully oxidized cytochrome bo3 from Escherichia coli has been studied in its oxidized and several ligand-bound forms using electron paramagnetic resonance (EPR) and magnetic circular dichroism (MCD) spectroscopies. In each form, the spin-coupled high-spin Fe(III) heme o3 and CuB(II) ion at the active site give rise to similar fast-relaxing broad features in the dual-mode X-band EPR spectra. Simulations of dual-mode spectra are presented which show that this EPR can arise only from a dinuclear site in which the metal ions are weakly coupled by an anisotropic exchange interaction of J 1 cm-1. A variable-temperature and magnetic field (VTVF) MCD study is also presented for the cytochrome bo3 fluoride and azide derivatives. New methods are used to extract the contribution to the MCD of the spin-coupled active site in the presence of strong transitions from low-spin Fe(III) heme b. Analysis of the MCD data, independent of the EPR study, also shows that the spin-coupling within the active site is weak with J approximately 1 cm-1. These conclusions overturn a long-held view that such EPR signals in bovine cytochrome c oxidase arise from an S' = 2 ground state resulting from strong exchange coupling (J > 10(2) cm-1) within the active site.

Long-term effect of land use change on soil quality: Afforestation and land abandonment in semi-arid Spain

NASA Astrophysics Data System (ADS)

Zethof, Jeroen; Cammeraat, Erik; Nadal-Romero, Estela

2016-04-01

Soils under the Mediterranean climate are vulnerable for degradation, especially after land abandonment. Abandonment is an important factor in the Mediterranean landscape as vegetation regeneration is hampered due to the characteristic semi-arid and sub-humid Mediterranean climate regime. During the past 70 year extensive afforestation projects have been conducted with the aim to protect landscapes and soils against degradation. While large investments are still being made, little is known about the impact of afforestation on soil quality on a longer time scale. During the past decade, there is a growing interest in qualifying and quantifying the carbon storage in soils by such afforestation projects, to get a better understanding of the carbon cycle and look for possibilities to fixate atmospheric CO2 in the soil. It is generally accepted that afforestation projects will increase the soil carbon pool, but data on this process is scarce. Therefore an intensive fieldwork has been carried out in Murcia, southeastern Spain to study the effects of land abandonment and afforestation on soil quality along a chronosequence and included two afforested areas (from the early '70s and 1993). The Pinus halepensis trees were planted in rows, for which the underlying calcrete was broken. Samples were taken to study changes in soil quality (Aggregate stability, Corg, N, P, K, Na), Soil Organic Carbon (SOC) stocks and soil hydraulic properties, such as infiltration and water retention, between the afforestation projects, abandoned agricultural plots of similar age, semi-natural vegetation, cereal crop fields and almond orchards. As the natural vegetation is characterized by a spotted pattern of bare areas and trees, forming so-called "islands of fertility", both bare and vegetation covered sub-sites were sampled. First results showed a positive effect of both land abandonment and afforestation on the soil aggregation. Especially the 40-year-old plots showed underneath trees similar values as the semi-natural sites, while the open areas in the afforested sites lag behind. Especially the soil at a depth of 10-20 cm showed a clear decrease in aggregate stability, while the surface layer showed a clear increase in aggregate stability. Abandonment sites showed a non-linear increase in soil quality, which means that aggregate stability slightly declines after 20 year of abandonment, but the positive change was less than on the afforested sites. Changes in vegetation along the chronosequence studied, could be expected to have an impact on organic matter input quality and quantity. Such changes in vegetation cover, structure and composition were not observed for the afforested sites in the field, but preliminary results suggest that the 40-year-old afforested sites could have a higher soil quality than the semi-natural sites.

NEW STUDIES OF URBAN FLOOD FREQUENCY IN THE SOUTHEASTERN UNITED STATES.

USGS Publications Warehouse

Sauer, Vernon B.

1986-01-01

Five reports dealing with flood magnitude and frequency in urban areas in the southeastern United States have been published during the past 2 years by the U. S. Geological Survey (USGS). These reports are based on data collected in Tampa and Tallahassee, Florida; Atlanta, Georgia; and several cities in Alabama and Tennessee. Each report contains regression equations useful for estimating flood peaks for selected recurrence intervals at ungauged urban sites. A nationwide study of urban flood characteristics by the USGS published in 1983 contains equations for estimating urban peak discharges for ungauged sites. At the time that the nationwide study was conducted, data from only 35 sites in the southeastern United States were available. The five new reports contain data for 88 additional sites. These new data show that the seven-parameter estimating equations developed in the nationwide study are unbiased and have prediction errors less than those described in the nationwide report.

Characterization of ambient fine particles in the northwestern area and Anchorage, Alaska.

PubMed

Kim, Eugene; Hopke, Philip K

2008-10-01

Ambient PM2.5 (particulate matter less than 2.5 microm in aerodynamic diameter) in the northwestern United States and Alaska is dominated by carbonaceous compounds associated with wood burning and transportation sources. PM2.5 source characterization studies analyzing recent PM2.5 speciation data have not been previously reported for these areas. In this study, ambient PM2.5 speciation samples collected at two monitoring sites located in the northwestern area, Olympic Peninsula, WA, and Portland, OR, and one monitoring site located in Anchorage, AK, were characterized through source apportionments. Gasoline vehicle, secondary sulfate, and wood smoke were the largest sources of PM2.5 collected at the Anchorage, Olympic, and Portland monitoring sites, respectively. Secondary sulfates showed an April peak at Anchorage and a November peak at Portland that are likely related to the increased photochemical reaction and long-range transport in Anchorage and meteorological stagnation in Portland. Secondary nitrate at the Olympic site showed a weak summer high peak that could be caused by seasonal tourism in the national park. Backward trajectories suggested that the elevated aged sea salt concentrations at the Portland monitoring site could be regional transport of sea salt that passed through other contaminated air sheds along the coast. Oil combustion emissions that might originate from ships and ferries were observed at the Olympic monitoring site.

Inhibition of Human Immunodeficiency Virus Replication by Antisense Oligodeoxynucleotides

NASA Astrophysics Data System (ADS)

Goodchild, John; Agrawal, Sudhir; Civeira, Maria P.; Sarin, Prem S.; Sun, Daisy; Zamecnik, Paul C.

1988-08-01

Twenty different target sites within human immunodeficiency virus (HIV) RNA were selected for studies of inhibition of HIV replication by antisense oligonucleotides. Target sites were selected based on their potential capacity to block recognition functions during viral replication. Antisense oligomers complementary to sites within or near the sequence repeated at the ends of retrovirus RNA (R region) and to certain splice sites were most effective. The effect of antisense oligomer length on inhibiting virus replication was also investigated, and preliminary toxicity studies in mice show that these compounds are toxic only at high levels. The results indicate potential usefulness for these oligomers in the treatment of patients with acquired immunodeficiency syndrome (AIDS) and AIDS-related complex either alone or in combination with other drugs.

Interactive effects of fire, soil climate, and moss on CO2 fluxes in black spruce ecosystems of interior Alaska

USGS Publications Warehouse

O'Donnell, J. A.; Turetsky, M.R.; Harden, J.W.; Manies, K.L.; Pruett, L.E.; Shetler, G.; Neff, J.C.

2009-01-01

Fire is an important control on the carbon (C) balance of the boreal forest region. Here, we present findings from two complementary studies that examine how fire modifies soil organic matter properties, and how these modifications influence rates of decomposition and C exchange in black spruce (Picea mariana) ecosystems of interior Alaska. First, we used laboratory incubations to explore soil temperature, moisture, and vegetation effects on CO2 and DOC production rates in burned and unburned soils from three study regions in interior Alaska. Second, at one of the study regions used in the incubation experiments, we conducted intensive field measurements of net ecosystem exchange (NEE) and ecosystem respiration (ER) across an unreplicated factorial design of burning (2 year post-fire versus unburned sites) and drainage class (upland forest versus peatland sites). Our laboratory study showed that burning reduced the sensitivity of decomposition to increased temperature, most likely by inducing moisture or substrate quality limitations on decomposition rates. Burning also reduced the decomposability of Sphagnum-derived organic matter, increased the hydrophobicity of feather moss-derived organic matter, and increased the ratio of dissolved organic carbon (DOC) to total dissolved nitrogen (TDN) in both the upland and peatland sites. At the ecosystem scale, our field measurements indicate that the surface organic soil was generally wetter in burned than in unburned sites, whereas soil temperature was not different between the burned and unburned sites. Analysis of variance results showed that ER varied with soil drainage class but not by burn status, averaging 0.9 ?? 0.1 and 1.4 ?? 0.1 g C m-2d-1 in the upland and peatland sites, respectively. However, a more complex general linear model showed that ER was controlled by an interaction between soil temperature, moisture, and burn status, and in general was less variable over time in the burned than in the unburned sites. Together, findings from these studies across different spatial scales suggest that although fire can create some soil climate conditions more conducive to rapid decomposition, rates of C release from soils may be constrained following fire by changes in moisture and/or substrate quality that impede rates of decomposition. ?? 2008 Springer Science+Business Media, LLC.

Interactive effects of fire, soil climate, and moss on CO2 fluxes in black spruce ecosystems of interior Alaska

USGS Publications Warehouse

O'Donnell, Jonathan A.; Turetsky, Merritt R.; Harden, Jennifer W.; Manies, Kristen L.; Pruett, L.E.; Shetler, Gordon; Neff, Jason C.

2009-01-01

Fire is an important control on the carbon (C) balance of the boreal forest region. Here, we present findings from two complementary studies that examine how fire modifies soil organic matter properties, and how these modifications influence rates of decomposition and C exchange in black spruce (Picea mariana) ecosystems of interior Alaska. First, we used laboratory incubations to explore soil temperature, moisture, and vegetation effects on CO2 and DOC production rates in burned and unburned soils from three study regions in interior Alaska. Second, at one of the study regions used in the incubation experiments, we conducted intensive field measurements of net ecosystem exchange (NEE) and ecosystem respiration (ER) across an unreplicated factorial design of burning (2 year post-fire versus unburned sites) and drainage class (upland forest versus peatland sites). Our laboratory study showed that burning reduced the sensitivity of decomposition to increased temperature, most likely by inducing moisture or substrate quality limitations on decomposition rates. Burning also reduced the decomposability of Sphagnum-derived organic matter, increased the hydrophobicity of feather moss-derived organic matter, and increased the ratio of dissolved organic carbon (DOC) to total dissolved nitrogen (TDN) in both the upland and peatland sites. At the ecosystem scale, our field measurements indicate that the surface organic soil was generally wetter in burned than in unburned sites, whereas soil temperature was not different between the burned and unburned sites. Analysis of variance results showed that ER varied with soil drainage class but not by burn status, averaging 0.9 ± 0.1 and 1.4 ± 0.1 g C m−2 d−1 in the upland and peatland sites, respectively. However, a more complex general linear model showed that ER was controlled by an interaction between soil temperature, moisture, and burn status, and in general was less variable over time in the burned than in the unburned sites. Together, findings from these studies across different spatial scales suggest that although fire can create some soil climate conditions more conducive to rapid decomposition, rates of C release from soils may be constrained following fire by changes in moisture and/or substrate quality that impede rates of decomposition.

Folic acid conjugated cross-linked acrylic polymer (FA-CLAP) hydrogel for site specific delivery of hydrophobic drugs to cancer cells.

PubMed

Pillai, Jisha Jayadevan; Thulasidasan, Arun Kumar Theralikattu; Anto, Ruby John; Chithralekha, Devika Nandan; Narayanan, Ashwanikumar; Kumar, Gopalakrishnapillai Sankaramangalam Vinod

2014-07-15

The hydrogel based system is found to be rarely reported for the delivery of hydrophobic drug due to the incompatibility of hydrophilicity of the polymer network and the hydrophobicity of drug. This problem can be solved by preparing semi-interpenetrating network of cross-linked polymer for tuning the hydrophilicity so as to entrap the hydrophobic drugs. The current study is to develop a folic acid conjugated cross-linked pH sensitive, biocompatible polymeric hydrogel to achieve a site specific drug delivery. For that, we have synthesized a folic acid conjugated PEG cross-linked acrylic polymer (FA-CLAP) hydrogel and investigated its loading and release of curcumin. The formed polymer hydrogel was then conjugated with folic acid for the site specific delivery of curcumin to cancer cells and then further characterized and conducted the cell uptake and cytotoxicity studies on human cervical cancer cell lines (HeLa). In this study, we synthesized folic acid conjugated cross-linked acrylic hydrogel for the delivery of hydrophobic drugs to the cancer site. Poly (ethyleneglycol) (PEG) diacrylate cross-linked acrylic polymer (PAA) was prepared via inverse emulsion polymerization technique and later conjugated it with folic acid (FA-CLAP). Hydrophobic drug curcumin is entrapped into it and investigated the entrapment efficiency. Characterization of synthesized hydogel was done by using Fourier Transform-Infrared spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), Differential Scanning Calorimetry (DSC). Polymerization and folate conjugation was confirmed by FT-IR spectroscopy. The release kinetics of drug from the entrapped form was studied which showed initial burst release followed by sustained release due to swelling and increased cross-linking. In vitro cytotoxicity and cell uptake studies were conducted in human cervical cancer (HeLa) cell lines. Results showed that curcumin entrapped folate conjugated cross-linked acrylic polymer (FA-CLAP) hydrogel showed higher cellular uptake than the non folate conjugated form. So this can be suggested as a better delivery system for site specific release of hydrophobic cancer drugs.

Magnetostratigraphy and Rock Magnetic Characterization of Baltic Sea IODP Expedition 347 Sites M0059 and M0060.

NASA Astrophysics Data System (ADS)

Herrero-Bervera, E.; Lau, J. K. S.; Snowball, I.

2014-12-01

We have studied the rock magnetic and paleomagnetic properties of a ~205 meter-long composite core from Site M0059 (Little Belt, BSB3) and ~210 meter-long core from Site M0060 (Anholt Loch, BSB1) recovering for the most part clays, (silty) sands, sandy clays and gravel. We deployed 454 (Site M0059) and 297 (site M0060) 8-cc discrete samples at approximately every 50 cm down-core from inside the respective site splices. The magnetic susceptibility (X) of the total of 751 samples was normalized to wet sample mass. We also performed stepwise alternating field demagnetization (AF) of the NRM up to a maximum field of 80 mT and the results show that the characteristic remanent magnetization (ChRM) was isolated by a series of weak AF's, typically between 0-25 mT, and that a low field of 5 mT removed weak VRM. After the removal of the VRM overprint the NRM intensity of the two sites is characterized by a general positive relationship with (X). The inclination data from both sites show positive and negative inclination values with a certain degree of scattering around 0°. At Site M0059 the upper lithologic units show inclinations that vary within 10 degrees either side of the geoaxial dipole prediction (GAD) for this location. In contrast the inclinations of Site M0060 show greater variability: only a few of the samples from the lower units approach this site's GAD prediction, although the inclination values in the upper lithologic units are closer to the GAD prediction. Measurements of the temperature dependence of bulk susceptibility (k-T) indicate the presence of at three magnetic mineral phases, which display characteristic Curie point temperatures of 360-400°C, 520 and 575°C for both sites and an additional Curie temperature of 610°C for Site M0060. We have obtained four 14C radiometric age determinations from 4 different stratigraphic levels at site 59A. These dates range in age from 4100+/-100 to 810+/-60 years and allow us to correlate the directional data to the FENNOSTACK regional master curve (Snowball et al. 2007). An interval of relatively steep inclinations between approximately 18 m and 16 m depth in Site M0060 probably corresponds to the period of steep inclination experienced in Fennsocandia between 3090 and 2590 Cal. a BP, which is delimited by inclination features e and e1, respectively, in FENNOSTACK.

Susceptibility of Anopheles gambiae to insecticides used for malaria vector control in Rwanda.

PubMed

Hakizimana, Emmanuel; Karema, Corine; Munyakanage, Dunia; Iranzi, Gad; Githure, John; Tongren, Jon Eric; Takken, Willem; Binagwaho, Agnes; Koenraadt, Constantianus J M

2016-12-01

The widespread emergence of resistance to pyrethroids is a major threat to the gains made in malaria control. To monitor the presence and possible emergence of resistance against a variety of insecticides used for malaria control in Rwanda, nationwide insecticide resistance surveys were conducted in 2011 and 2013. Larvae of Anopheles gambiae sensu lato mosquitoes were collected in 12 sentinel sites throughout Rwanda. These were reared to adults and analysed for knock-down and mortality using WHO insecticide test papers with standard diagnostic doses of the recommended insecticides. A sub-sample of tested specimens was analysed for the presence of knockdown resistance (kdr) mutations. A total of 14,311 mosquitoes were tested and from a sample of 1406 specimens, 1165 (82.9%) were identified as Anopheles arabiensis and 241 (17.1%) as Anopheles gambiae sensu stricto. Mortality results indicated a significant increase in resistance to lambda-cyhalothrin from 2011 to 2013 in 83% of the sites, permethrin in 25% of the sites, deltamethrin in 25% of the sites and DDT in 50% of the sites. Mosquitoes from 83% of the sites showed full susceptibility to bendiocarb and 17% of sites were suspected to harbour resistance that requires further confirmation. No resistance was observed to fenitrothion in all study sites during the entire survey. The kdr genotype results in An. gambiae s.s. showed that 67 (50%) possessed susceptibility (SS) alleles, while 35 (26.1%) and 32 (23.9%) mosquitoes had heterozygous (RS) and homozygous (RR) alleles, respectively. Of the 591 An. arabiensis genotyped, 425 (71.9%) possessed homozygous (SS) alleles while 158 (26.7%) and 8 (1.4%) had heterozygous (RS) and homozygous (RR) alleles, respectively. Metabolic resistance involving oxidase enzymes was also detected using the synergist PBO. This is the first nationwide study of insecticide resistance in malaria vectors in Rwanda. It shows the gradual increase of insecticide resistance to pyrethroids (lambda-cyhalothrin, deltamethrin, permethrin) and organochlorines (DDT) and the large presence of target site insensitivity. The results demonstrate the need for Rwanda to expand monitoring for insecticide resistance including further metabolic resistance testing and implement an insecticide resistance management strategy to sustain the gains made in malaria control.

Direct-current resistivity profiling at the Pecos River Ecosystem Project study site near Mentone, Texas, 2006

USGS Publications Warehouse

Teeple, Andrew; McDonald, Alyson K.; Payne, Jason; Kress, Wade H.

2009-01-01

The U.S. Geological Survey, in cooperation with Texas A&M University AgriLife, did a surface geophysical investigation at the Pecos River Ecosystem Project study site near Mentone in West Texas intended to determine shallow (to about 14 meters below the water [river] surface) subsurface composition (lithology) in and near treated (eradicated of all saltcedar) and control (untreated) riparian zone sites during June-August 2006. Land-based direct-current resistivity profiling was applied in a 240-meter section of the riverbank at the control site, and waterborne direct-current continuous resistivity profiling (CRP) was applied along a 2.279-kilometer reach of the river adjacent to both sites to collect shallow subsurface resistivity data. Inverse modeling was used to obtain a nonunique estimate of the true subsurface resistivity from apparent resistivity calculated from the field measurements. The land-based survey showed that the sub-surface at the control site generally is of relatively low resis-tivity down to about 4 meters below the water surface. Most of the section from about 4 to 10 meters below the water surface is of relatively high resistivity. The waterborne CRP surveys convey essentially the same electrical representation of the lithology at the control site to 10 meters below the water surface; but the CRP surveys show considerably lower resistivity than the land-based survey in the subsection from about 4 to 10 meters below the water surface. The CRP surveys along the 2.279-kilometer reach of the river adjacent to both the treated and control sites show the same relatively low resistivity zone from the riverbed to about 4 meters below the water surface evident at the control site. A slightly higher resistivity zone is observed from about 4 to 14 meters below the water surface along the upstream approximately one-half of the profile than along the downstream one-half. The variations in resistivity could not be matched to variations in lithology because sufficient rock samples were not available.

Methanopyrus kandleri topoisomerase V contains three distinct AP lyase active sites in addition to the topoisomerase active site

PubMed Central

Rajan, Rakhi; Osterman, Amy; Mondragón, Alfonso

2016-01-01

Topoisomerase V (Topo-V) is the only topoisomerase with both topoisomerase and DNA repair activities. The topoisomerase activity is conferred by a small alpha-helical domain, whereas the AP lyase activity is found in a region formed by 12 tandem helix-hairpin-helix ((HhH)2) domains. Although it was known that Topo-V has multiple repair sites, only one had been mapped. Here, we show that Topo-V has three AP lyase sites. The atomic structure and Small Angle X-ray Scattering studies of a 97 kDa fragment spanning the topoisomerase and 10 (HhH)2 domains reveal that the (HhH)2 domains extend away from the topoisomerase domain. A combination of biochemical and structural observations allow the mapping of the second repair site to the junction of the 9th and 10th (HhH)2 domains. The second site is structurally similar to the first one and to the sites found in other AP lyases. The 3rd AP lyase site is located in the 12th (HhH)2 domain. The results show that Topo-V is an unusual protein: it is the only known protein with more than one (HhH)2 domain, the only known topoisomerase with dual activities and is also unique by having three AP lyase repair sites in the same polypeptide. PMID:26908655

Sediment compaction in deepwater basin of the South China Sea: estimation from ODP 184 and IODP 349 drilling well data.

NASA Astrophysics Data System (ADS)

Tuoyu, W.; Xie, Y.

2017-12-01

Abnormal compaction in deepwater basins not only cause serious soft sediment deformation, but also significantly affect the safety of the drilling campaign. Therefore, study the compaction condition in the sediments would be an important task in the deepwater basin and associate with the environment variation. We analyze the drilling data from the ODP Leg 184 Site 1144, 1146, 1148 and the IODP Leg 349 Site U1431, U1432, U1433, U1435 to study the sediment compaction and controls in the northern South China Sea. We have found the sedimentation rate, sediment content, distribution area and buried depth control the sediment compaction in deepwater basin of the South China Sea. Among all the factors, the sediment content is the most important factor. The fitted normal compacted coefficients and the mudline porosity for interval 50 m shows disciplinary variation versus depth. The pore pressure predicted from different fitted results shows different overpressure situation. The normal compaction trend from Site 1144 reflects the porosity variation trend in stable deposition basins in the northern South China Sea. The predicted pore pressure shows overpressure at Site 1144, which is attributed to compaction disequilibrium. Nevertheless, the mixed lithology column may influence the predicted overpressure at Site 1148, which is responsible for the confusing result. Above all. we find that sediment compaction should be act as a proxy for pore pressure in the deepwater basin of the South China Sea. The study will help us to nature of sedimentation in the deepwater basin set up and can be used as analog for older sediments deposited in the similar kind of depositional environment in deepwater basin of the South China Sea.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Safira, Nabila, E-mail: safira.nabila@ymail.com; Anggraeni, Tjandra, E-mail: tjandra@sith.itb.ac.id

Several studies had shown that lead (Pb) in the environment could accumulate in bees, which in turn could affect the quality of the resulting product. In this study, forager stingless bees (Trigona sp.) and its product (propolis) collected from a stingless bees apiculture. This apiculture had two apiary sites which were distinguished by its environmental setting. Apiary site in Cilutung had a forest region environmental setting, while apiary site in Maribaya was located beside the main road. The objective of this study was to determine the extent of lead concentration in propolis originated from both apiary sites and establish themore » correlation between lead concentration in propolis and lead level in forager stingless bees. Forager bees and propolis samples were originated from 50 bees colonies (Cilutung) and 44 bees colonies (Maribaya). They were analyzed using AAS-GF (Atomic Absorption Spectrometre–Graphite Furnace) to determine the level of lead concentration. The results showed that the average level of lead in propolis originated from Cilutung (298.08±73.71 ppb) was lower than the average level of lead in forager bees which originated from Maribaya (330.64±156.34 ppb). However, these values did not show significant difference (p>0.05). There was no significant difference (p>0.05) between the average level of lead in forager bees which originated from Cilutung (118.08±30.46 ppb) and Maribaya (128.82±39.66 ppb). However, these values did not show significant difference (p>0.05). In conclusion, the average level of lead concentration in propolis in both sites had passed the maximum permission standard of lead for food in Indonesia. There was no correlation between lead concentration in propolis and forager stingless bees.« less

Analysis of lead concentration in forager stingless bees Trigona sp. (hymenoptera: Apidae) and propolis at Cilutung and Maribaya, West Java

NASA Astrophysics Data System (ADS)

Safira, Nabila; Anggraeni, Tjandra

2015-09-01

Several studies had shown that lead (Pb) in the environment could accumulate in bees, which in turn could affect the quality of the resulting product. In this study, forager stingless bees (Trigona sp.) and its product (propolis) collected from a stingless bees apiculture. This apiculture had two apiary sites which were distinguished by its environmental setting. Apiary site in Cilutung had a forest region environmental setting, while apiary site in Maribaya was located beside the main road. The objective of this study was to determine the extent of lead concentration in propolis originated from both apiary sites and establish the correlation between lead concentration in propolis and lead level in forager stingless bees. Forager bees and propolis samples were originated from 50 bees colonies (Cilutung) and 44 bees colonies (Maribaya). They were analyzed using AAS-GF (Atomic Absorption Spectrometre-Graphite Furnace) to determine the level of lead concentration. The results showed that the average level of lead in propolis originated from Cilutung (298.08±73.71 ppb) was lower than the average level of lead in forager bees which originated from Maribaya (330.64±156.34 ppb). However, these values did not show significant difference (p>0.05). There was no significant difference (p>0.05) between the average level of lead in forager bees which originated from Cilutung (118.08±30.46 ppb) and Maribaya (128.82±39.66 ppb). However, these values did not show significant difference (p>0.05). In conclusion, the average level of lead concentration in propolis in both sites had passed the maximum permission standard of lead for food in Indonesia. There was no correlation between lead concentration in propolis and forager stingless bees.

Changes in Fire-Derived Soil Black Carbon Storage in a Sub-humid Woodland

NASA Astrophysics Data System (ADS)

White, J. D.; Yao, J.; Murray, D. B.; Hockaday, W. C.

2014-12-01

Fire-derived black carbon (BC) in soil, including charcoal, represents a potentially important fraction of terrestrial carbon cycling due to its presumed long persistence in soil. Interpretation of site BC retention is important for assessing feedbacks to ecosystem processes including nutrient and water cycling. However, interaction between vegetation disturbance, BC formation, and off site transport may exist that complicate interpretation of BC addition to soils from wildfire or prescribed burns directly. To investigate the relationship between disturbance and site retention on soil BC, we determined BC concentrations for a woodland in central Texas, USA, from study plots in hilly terrain with a fire scar dendrochronology spanning 100 years. BC values were determined from 13C nuclear magnetic resonance (NMR) spectroscopy. Estimated values showed mean BC concentration of 2.73 ± 3.06 g BC kg-1 (0.91 ± 0.51 kg BC m-2) for sites with fire occurrence within the last 40 years compared with BC values of1.21 ± 1.70 g BC kg-1 soil (0.18 ± 0.14 kg BC m-2) for sites with fire 40 - 100 years ago. Sites with no tree ring evidence of fire during the last 100 years had the lowest mean soil BC concentration of 0.05 ± 0.11 g BC kg-1 (0.02 ± 0.03 kg BC m-2). Molecular proxies of stability (lignin/N) and decomposition (Alkyl C/O-Alky C) showed no differences across the sites, indicating that low potential for BC mineralization. Modeled soil erosion and time since fire from fire scar data showed that soil BC concentrations were inversely correlated. A modified the ecosystem process model, Biome-BGC, was also used simulate the effects of fire disturbance with different severities and seasonality on C cycling related to the BC production, effect on soil water availability, and off-site transport. Results showed that BC impacts on ecosystem processes, including net ecosystem exchange and leaf area development, were predominantly related to fire frequency. Site BC loss rates were affected by initial slope-affected erosion, fire severity, vegetation type, and rate of vegetation recovery. The simulation results showed that fire types, such as high severity, was generally associated with low site BC retention related to low vertical transfer of BC into soils, buoyancy of BC particles, and surface runoff from unvegetated soils.

Physicochemical characteristics, mutagenicity and genotoxicity of airborne particles under industrial and rural influences in Northern Lebanon.

PubMed

Melki, Pamela N; Ledoux, Frédéric; Aouad, Samer; Billet, Sylvain; El Khoury, Bilal; Landkocz, Yann; Abdel-Massih, Roula M; Courcot, Dominique

2017-08-01

In this work, the main objectives were to assess the mutagenic and genotoxic effects of fine particulate matter collected in an industrial influenced site in comparison with a non-industrial influenced one (rural site) and to relate the particulate matter (PM) composition to the observed genotoxic effects. At the industrial influenced site, higher concentrations of phosphates, trace metals, and polycyclic aromatic hydrocarbons (PAHs) in particles could be related to the contributions of quarries, fertilizer producer, cement plants, and tires burning. Gasoline and diesel combustion contributions were evidenced in particles collected at both sites. Particles collected under industrial influence showed a higher mutagenic potential on three tested strains of Salmonella typhimurium (TA98, YG1041, and TA102), and especially on the YG1041, compared to particles from the rural site. Furthermore, only particles collected in the vicinity of the industrial site showed a tendency to activate the SOS responses in Escherichia coli PQ37, which is indicative of DNA damage as a result of exposure of the bacteria cells to the action of mutagenic samples. The mutagenicity and genotoxicity of the industrial PM 2.5-0.3 particulates may be attributed to its composition especially in organic compounds. This study showed that proximity of industries can affect local PM composition as well as PM genotoxic and mutagenic potential.

Magnetic fluctuations and superconducting properties of CaKFe 4 As 4 studied by As 75 NMR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui, J.; Ding, Q. -P.; Meier, W. R.

In this paper, we report 75As nuclear magnetic resonance (NMR) studies on a new iron-based superconductor, CaKFe 4As 4, with T c = 35 K. 75As NMR spectra show two distinct lines corresponding to the As(1) and As(2) sites close to the K and Ca layers, respectively, revealing that K and Ca layers are well ordered without site inversions. We found that nuclear quadrupole frequencies ν Q of the As(1) and As(2) sites show an opposite temperature T dependence. Nearly T independent behavior of the Knight shifts K is observed in the normal state, and a sudden decrease in Kmore » in the superconducting (SC) state suggests spin-singlet Cooper pairs. 75As spin-lattice relaxation rates 1/T 1 show a power-law T dependence with different exponents for the two As sites. The isotropic antiferromagnetic spin fluctuations characterized by the wave vector q = (π, 0) or (0, π) in the single-iron Brillouin zone notation are revealed by 1/T 1T and K measurements. Such magnetic fluctuations are necessary to explain the observed temperature dependence of the 75As quadrupole frequencies, as evidenced by our first-principles calculations. Finally, in the SC state, 1/T 1 shows a rapid decrease below T c without a Hebel-Slichter peak and decreases exponentially at low T, consistent with an s ± nodeless two-gap superconductor.« less

Magnetic fluctuations and superconducting properties of CaKFe 4 As 4 studied by As 75 NMR

DOE PAGES

Cui, J.; Ding, Q. -P.; Meier, W. R.; ...

2017-09-25

In this paper, we report 75As nuclear magnetic resonance (NMR) studies on a new iron-based superconductor, CaKFe 4As 4, with T c = 35 K. 75As NMR spectra show two distinct lines corresponding to the As(1) and As(2) sites close to the K and Ca layers, respectively, revealing that K and Ca layers are well ordered without site inversions. We found that nuclear quadrupole frequencies ν Q of the As(1) and As(2) sites show an opposite temperature T dependence. Nearly T independent behavior of the Knight shifts K is observed in the normal state, and a sudden decrease in Kmore » in the superconducting (SC) state suggests spin-singlet Cooper pairs. 75As spin-lattice relaxation rates 1/T 1 show a power-law T dependence with different exponents for the two As sites. The isotropic antiferromagnetic spin fluctuations characterized by the wave vector q = (π, 0) or (0, π) in the single-iron Brillouin zone notation are revealed by 1/T 1T and K measurements. Such magnetic fluctuations are necessary to explain the observed temperature dependence of the 75As quadrupole frequencies, as evidenced by our first-principles calculations. Finally, in the SC state, 1/T 1 shows a rapid decrease below T c without a Hebel-Slichter peak and decreases exponentially at low T, consistent with an s ± nodeless two-gap superconductor.« less

Seasonal and diel movements of white sturgeon in the lower columbia river

USGS Publications Warehouse

Parsley, M.J.; Popoff, N.D.; Van Der Leeuw, B. K.; Wright, C.D.

2008-01-01

Continuous monitoring of the movements and depths used by white sturgeon Acipenser transmontanus with acoustic telemetry technologies in the lower Columbia River provided information on diel and seasonal migrations, local movements, and site fidelity. White sturgeon moved to shallower water at night and showed greater activity, inferred from rates of movement, than during daytime. The extent of local movement within a season was variable among fish; some fish readily moved among habitats while the movements of others were more constrained. White sturgeon were absent from the study area (river kilometers 45-52) during winter and returned from upstream during the spring, confirming an upstream seasonal migration in the fall and downstream migration in spring. The return of individual fish and reoccupation of areas previously inhabited showed that some white sturgeon exhibit site fidelity. This work shows that studies seeking to characterize habitat for white sturgeon need to be cognizant of diel migrations and site fidelity. We urge caution in the use of limited fish location data to describe habitats if diel activities and fine-scale movements are not known.

Forest impacts on snow accumulation and ablation across an elevation gradient in a temperate montane environment

NASA Astrophysics Data System (ADS)

Roth, Travis R.; Nolin, Anne W.

2017-11-01

Forest cover modifies snow accumulation and ablation rates via canopy interception and changes in sub-canopy energy balance processes. However, the ways in which snowpacks are affected by forest canopy processes vary depending on climatic, topographic and forest characteristics. Here we present results from a 4-year study of snow-forest interactions in the Oregon Cascades. We continuously monitored snow and meteorological variables at paired forested and open sites at three elevations representing the Low, Mid, and High seasonal snow zones in the study region. On a monthly to bi-weekly basis, we surveyed snow depth and snow water equivalent across 900 m transects connecting the forested and open pairs of sites. Our results show that relative to nearby open areas, the dense, relatively warm forests at Low and Mid sites impede snow accumulation via canopy snow interception and increase sub-canopy snowpack energy inputs via longwave radiation. Compared with the Forest sites, snowpacks are deeper and last longer in the Open site at the Low and Mid sites (4-26 and 11-33 days, respectively). However, we see the opposite relationship at the relatively colder High sites, with the Forest site maintaining snow longer into the spring by 15-29 days relative to the nearby Open site. Canopy interception efficiency (CIE) values at the Low and Mid Forest sites averaged 79 and 76 % of the total event snowfall, whereas CIE was 31 % at the lower density High Forest site. At all elevations, longwave radiation in forested environments appears to be the primary energy component due to the maritime climate and forest presence, accounting for 93, 92, and 47 % of total energy inputs to the snowpack at the Low, Mid, and High Forest sites, respectively. Higher wind speeds in the High Open site significantly increase turbulent energy exchanges and snow sublimation. Lower wind speeds in the High Forest site create preferential snowfall deposition. These results show the importance of understanding the effects of forest cover on sub-canopy snowpack evolution and highlight the need for improved forest cover model representation to accurately predict water resources in maritime forests.

Predict and Analyze Protein Glycation Sites with the mRMR and IFS Methods

PubMed Central

Gu, Wenxiang; Zhang, Wenyi; Wang, Jianan

2015-01-01

Glycation is a nonenzymatic process in which proteins react with reducing sugar molecules. The identification of glycation sites in protein may provide guidelines to understand the biological function of protein glycation. In this study, we developed a computational method to predict protein glycation sites by using the support vector machine classifier. The experimental results showed that the prediction accuracy was 85.51% and an overall MCC was 0.70. Feature analysis indicated that the composition of k-spaced amino acid pairs feature contributed the most for glycation sites prediction. PMID:25961025

Effects of anthropogenic activities on chemical contamination within the Grand Canal, China.

PubMed

Wang, Xiaolong; Han, Jingyi; Xu, Ligang; Gao, Junfeng; Zhang, Qi

2011-06-01

Contamination of nutrients and heavy metals within aquatic system is of great concern due to its potential impact on human and animal health. The Grand Canal of China, the largest artificial river in the world, is of great importance in supplying water resource, transporting cargo, and recreating resident, as well as great historical heritage. This study assessed and examined the impact of human activities on characters of contamination distribution within the section of the Canal in Taihu watershed. Physicochemical parameters of surface water quality were determined monthly from the year 2004 to 2006 at 11 sites that were influenced by different anthropogenic activities along the Canal. Moreover, contaminations at surface sediments (20 cm) at the same locations were also analyzed in September 2006. Results showed that the Canal had been seriously polluted, which was characterized with high spatial variations in contaminations distribution. The sites influenced mainly by industry and urbanization showed higher contents of nutrients and lower levels of dissolve oxygen than other sites. Concentrations of nitrogen at all studied sites exceeded the worst level of surface water quality according to the National Criterion of Surface Water Quality, China, with the average values varying from 2.27 to 10.34 mg/L. Furthermore, the site influenced mainly by industry (i.e., Site 4) presented the highest contents of cadmium (3.453 mg/kg), chromium (196.87 mg/kg), nickel (87.12 mg/kg), zinc (381.8 mg/kg), and copper (357.32 mg/kg). While sites in vicinity to cities had presented relatively higher contents of metals, especially for the site located downstream of Changzhou City (Site 3) had presented the highest contents of mercury (1.64 mg/kg) and lead (197.62 mg/kg). Copper at Sites 2 to 6, Nickel at Sites 2 to 9 except for Site 7, chromium, lead, and zinc at Sites 3 to 6 had exceeded New York State Department of Environmental Conservation (NYSDEC) Severe Effect Level (SEL). By multivariate statistical, nutrient variables, companied with V-phen, had contributed the most variation of water quality, while nutrient and metals had explained the most part of total variance of contaminations in sediment. This study indicated that the canal had been polluted severely and urgently need to control.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rajan, Rakhi; Taneja, Bhupesh; Mondragón, Alfonso

Topoisomerase V is an archaeal type I topoisomerase that is unique among topoisomerases due to presence of both topoisomerase and DNA repair activities in the same protein. It is organized as an N-terminal topoisomerase domain followed by 24 tandem helix-hairpin-helix (HhH) motifs. Structural studies have shown that the active site is buried by the (HhH) motifs. Here we show that the N-terminal domain can relax DNA in the absence of any HhH motifs and that the HhH motifs are required for stable protein-DNA complex formation. Crystal structures of various topoisomerase V fragments show changes in the relative orientation of themore » domains mediated by a long bent linker helix, and these movements are essential for the DNA to enter the active site. Phosphate ions bound to the protein near the active site helped model DNA in the topoisomerase domain and show how topoisomerase V may interact with DNA.« less

On the use of haplotype phylogeny to detect disease susceptibility loci

PubMed Central

Bardel, Claire; Danjean, Vincent; Hugot, Jean-Pierre; Darlu, Pierre; Génin, Emmanuelle

2005-01-01

Background The cladistic approach proposed by Templeton has been presented as promising for the study of the genetic factors involved in common diseases. This approach allows the joint study of multiple markers within a gene by considering haplotypes and grouping them in nested clades. The idea is to search for clades with an excess of cases as compared to the whole sample and to identify the mutations defining these clades as potential candidate disease susceptibility sites. However, the performance of this approach for the study of the genetic factors involved in complex diseases has never been studied. Results In this paper, we propose a new method to perform such a cladistic analysis and we estimate its power through simulations. We show that under models where the susceptibility to the disease is caused by a single genetic variant, the cladistic test is neither really more powerful to detect an association nor really more efficient to localize the susceptibility site than an individual SNP testing. However, when two interacting sites are responsible for the disease, the cladistic analysis greatly improves the probability to find the two susceptibility sites. The impact of the linkage disequilibrium and of the tree characteristics on the efficiency of the cladistic analysis are also discussed. An application on a real data set concerning the CARD15 gene and Crohn disease shows that the method can successfully identify the three variant sites that are involved in the disease susceptibility. Conclusion The use of phylogenies to group haplotypes is especially interesting to pinpoint the sites that are likely to be involved in disease susceptibility among the different markers identified within a gene. PMID:15904492

Effect of irrigation on soil health: a case study of the Ikere irrigation project in Oyo State, southwest Nigeria.

PubMed

Adejumobi, M A; Awe, G O; Abegunrin, T P; Oyetunji, O M; Kareem, T S

2016-12-01

Irrigated agriculture is one of the significant contributors to the food security of the millennium development goals (MDGs); however, the modification of soil matrix by irrigation could alter the overall soil health due to changes in soil properties and processes. The objective of the study was to evaluate the effect of irrigation on soil quality status of the Ikere center pivot irrigation project site in Oyo State, southwest Nigeria. Disturbed soil samples were collected from 0 to 30, 30 to 60, and 60 to 90-cm layers from four different sites in three replicates, within the project location for the determination of soil bio-chemical properties. The average values of sodium adsorption ratio (SAR) < 13, electrical conductivity (EC) <4 μS/cm, and pH < 8.5 showed that the soil condition is normal in relation to salinity and sodicity hazards. The effective cation exchange capacity (ECEC), soil organic matter (SOM), total nitrogen (TN), and calcium ion (Ca 2+ ) concentrations were low while the available phosphorus (P) was moderate. The principal component analysis showed EC, ECEC, SAR, SOM, and TN as the minimum data set (MDS) for monitoring and assessing the soil quality status of this irrigation field. In terms of bio-chemical properties, the soil quality index (SQI) of the field was average (about 0.543) while the sampling locations were ranked as site 2 > site 4 > site 3 > site 1 in terms of SQI. The results of this study are designated as baseline for future evaluation of soil quality status of this irrigation field and further studies should incorporate soil physical and more biological properties when considering overall soil quality status.

Effect of site level environmental variables, spatial autocorrelation and sampling intensity on arthropod communities in an ancient temperate lowland woodland area.

PubMed

Horak, Jakub

2013-01-01

The interaction of arthropods with the environment and the management of their populations is a focus of the ecological agenda. Spatial autocorrelation and under-sampling may generate bias and, when they are ignored, it is hard to determine if results can in any way be trusted. Arthropod communities were studied during two seasons and using two methods: window and panel traps, in an area of ancient temperate lowland woodland of Zebracka (Czech Republic). The composition of arthropod communities was studied focusing on four site level variables (canopy openness, diameter in the breast height and height of tree, and water distance) and finally analysed using two approaches: with and without effects of spatial autocorrelation. I found that the proportion of variance explained by space cannot be ignored (≈20% in both years). Potential bias in analyses of the response of arthropods to site level variables without including spatial co-variables is well illustrated by redundancy analyses. Inclusion of space led to more accurate results, as water distance and tree diameter were significant, showing approximately the same ratio of explained variance and direction in both seasons. Results without spatial co-variables were much more disordered and were difficult to explain. This study showed that neglecting the effects of spatial autocorrelation could lead to wrong conclusions in site level studies and, furthermore, that inclusion of space may lead to more accurate and unambiguous outcomes. Rarefactions showed that lower sampling intensity, when appropriately designed, can produce sufficient results without exploitation of the environment.

Critical Factors Driving the High Volumetric Uptake of Methane in Cu₃(btc)₂.

PubMed

Hulvey, Zeric; Vlaisavljevich, Bess; Mason, Jarad A; Tsivion, Ehud; Dougherty, Timothy P; Bloch, Eric D; Head-Gordon, Martin; Smit, Berend; Long, Jeffrey R; Brown, Craig M

2015-08-26

A thorough experimental and computational study has been carried out to elucidate the mechanistic reasons for the high volumetric uptake of methane in the metal-organic framework Cu3(btc)2 (btc(3-) = 1,3,5-benzenetricarboxylate; HKUST-1). Methane adsorption data measured at several temperatures for Cu3(btc)2, and its isostructural analogue Cr3(btc)2, show that there is little difference in volumetric adsorption capacity when the metal center is changed. In situ neutron powder diffraction data obtained for both materials were used to locate four CD4 adsorption sites that fill sequentially. This data unequivocally shows that primary adsorption sites around, and within, the small octahedral cage in the structure are favored over the exposed Cu(2+) or Cr(2+) cations. These results are supported by an exhaustive parallel computational study, and contradict results recently reported using a time-resolved diffraction structure envelope (TRDSE) method. Moreover, the computational study reveals that strong methane binding at the open metal sites is largely due to methane-methane interactions with adjacent molecules adsorbed at the primary sites instead of an electronic interaction with the metal center. Simulated methane adsorption isotherms for Cu3(btc)2 are shown to exhibit excellent agreement with experimental isotherms, allowing for additional simulations that show that modifications to the metal center, ligand, or even tuning the overall binding enthalpy would not improve the working capacity for methane storage over that measured for Cu3(btc)2 itself.

Siting MSW landfill using weighted linear combination and analytical hierarchy process (AHP) methodology in GIS environment (case study: Karaj).

PubMed

Moeinaddini, Mazaher; Khorasani, Nematollah; Danehkar, Afshin; Darvishsefat, Ali Asghar; Zienalyan, Mehdi

2010-05-01

Selection of landfill site is a complex process and needs many diverse criteria. The purpose of this paper is to evaluate the suitability of the studied site as landfill for MSW in Karaj. Using weighted linear combination (WLC) method and spatial cluster analysis (SCA), suitable sites for allocation of landfill for a 20-year period were identified. For analyzing spatial auto-correlation of the land suitability map layer (LSML), Maron's I was used. Finally, using the analytical hierarchy process (AHP), the most preferred alternative for the landfill siting was identified. Main advantages of AHP are: relative ease of handling multiple criteria, easy to understand and effective handling of both qualitative and quantitative data. As a result, 6% of the study area is suitable for landfill siting and third alternative was identified as the most preferred for siting MSW landfill by AHP. The ranking of alternatives were obtained only by applying the WLC approach showed different results from the AHP. The WLC should be used only for the identification of alternatives and the AHP is used for prioritization. We suggest the employed procedure for other similar regions. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Managing for desired experiences and site preferences: the case of fee-fishing anglers.

PubMed

Schuett, Michael A; Pierskalla, Chad D

2007-02-01

Fee-fishing involves paying a fee for the privilege of fishing a body of water where fish populations are enhanced by stocking fish. Past literature on this activity has focused more on the operation of the enterprise and management of the fish than the people and site characteristics. The objectives of the study were to profile anglers and describe their site/management preferences. This study utilized an on-site interview and mail-back questionnaire at fee-fishing establishments in West Virginia (n = 212). Factor analysis of desired recreation experiences yielded five factors: Experience nature & adventure, Stress release & relaxation, Trophy fishing, Escape, and Family time. Cluster analysis showed that these anglers can be segmented into two distinct clusters, differing by sociodemographic characteristics, fishing behavior, and site/management preferences. The findings from this study provide baseline data to aid public resource managers and fee-fishing business owners in determining how to provide satisfying outdoor experiences and deliver desired services on-site. Future research will be needed from additional fee-fishing sites to obtain more detail about this outdoor recreation cohort and be able to generalize to a larger population of participants.

Managing for Desired Experiences and Site Preferences: The Case of Fee-Fishing Anglers

NASA Astrophysics Data System (ADS)

Schuett, Michael A.; Pierskalla, Chad D.

2007-02-01

Fee-fishing involves paying a fee for the privilege of fishing a body of water where fish populations are enhanced by stocking fish. Past literature on this activity has focused more on the operation of the enterprise and management of the fish than the people and site characteristics. The objectives of the study were to profile anglers and describe their site/management preferences. This study utilized an on-site interview and mail-back questionnaire at fee-fishing establishments in West Virginia ( n = 212). Factor analysis of desired recreation experiences yielded five factors: Experience nature & adventure, Stress release & relaxation, Trophy fishing, Escape, and Family time. Cluster analysis showed that these anglers can be segmented into two distinct clusters, differing by sociodemographic characteristics, fishing behavior, and site/management preferences. The findings from this study provide baseline data to aid public resource managers and fee-fishing business owners in determining how to provide satisfying outdoor experiences and deliver desired services on-site. Future research will be needed from additional fee-fishing sites to obtain more detail about this outdoor recreation cohort and be able to generalize to a larger population of participants.

Exploring the Extreme Universe! (2nd Edition)

NASA Technical Reports Server (NTRS)

White, Nicholas E.

2002-01-01

A large array of web sites devoted to the science that the NASA Goddard Space Flight Center Laboratory for High Energy Astrophysics (LHEA) studies have been frozen in time and included on this CD. Featured are five of our 'Understanding the Extreme Universe' sites, which offer explanations about cosmic ray, gamma ray, and X-ray science and satellites, as well as cosmic distances. They also include images and engaging activities that are great for helping both children and adults to learn more about science and basic physical principles. The 'Missions That Take Us There' section contains web sites on the satellite, balloon-borne, International Space Station, and rocket missions in our Laboratory that study X-rays, gamma rays, and cosmic rays. There are also two multi-mission sites and an experiment that measures Earth's UV light in preparation for a future cosmic ray mission. Most of the sites on this CD contain high-resolution images that are great for scientific presentations, study, or just your own enjoyment. This CD shows our web sites as they existed in April of 2001. We have made sure to include the WWW address for every site, so you will know where to go to access the most current versions of them.

Rapid assessment of environmental health risks posed by mining operations in low- and middle-income countries: selected case studies.

PubMed

Caravanos, Jack; Ericson, Bret; Ponce-Canchihuamán, Johny; Hanrahan, David; Block, Meredith; Susilorini, Budi; Fuller, Richard

2013-11-01

Previous studies have evaluated associated health risks and human exposure pathways at mining sites. Others have provided estimates of the scale of the issue based in part on surveys. However, a global census of mining-related hazardous waste sites has been lacking. The Toxic Sites Identification Program (TSIP) implemented by Blacksmith Institute (New York, NY, USA) since 2009 is an ongoing effort to catalogue a wide range of chemically contaminated sites with a potential human health risk (Ericson et al., Environ Monit Assess doi:10.1007/s 10661-012-2665-2, 2012). The TSIP utilizes a rapid assessment instrument, the Initial Site Screening (ISS), to quickly and affordably identify key site criteria including human exposure pathways, estimated populations at risk, and sampling information. The resulting ISS allows for comparison between sites exhibiting different contaminants and pollution sources. This paper explores the results of a subset of ISSs completed at 131 artisanal and small-scale gold mining areas and 275 industrial mining and ore processing sites in 45 countries. The authors show that the ISS captures key data points, allowing for prioritization of sites for further investigation or remedial activity.

Allosteric binding sites in Rab11 for potential drug candidates

PubMed Central

2018-01-01

Rab11 is an important protein subfamily in the RabGTPase family. These proteins physiologically function as key regulators of intracellular membrane trafficking processes. Pathologically, Rab11 proteins are implicated in many diseases including cancers, neurodegenerative diseases and type 2 diabetes. Although they are medically important, no previous study has found Rab11 allosteric binding sites where potential drug candidates can bind to. In this study, by employing multiple clustering approaches integrating principal component analysis, independent component analysis and locally linear embedding, we performed structural analyses of Rab11 and identified eight representative structures. Using these representatives to perform binding site mapping and virtual screening, we identified two novel binding sites in Rab11 and small molecules that can preferentially bind to different conformations of these sites with high affinities. After identifying the binding sites and the residue interaction networks in the representatives, we computationally showed that these binding sites may allosterically regulate Rab11, as these sites communicate with switch 2 region that binds to GTP/GDP. These two allosteric binding sites in Rab11 are also similar to two allosteric pockets in Ras that we discovered previously. PMID:29874286

Interstitial water studies on small core samples, Deep Sea Drilling Project, Leg 8

USGS Publications Warehouse

Manheim, F.T.; Sayles, F.L.

1971-01-01

Leg 8 sites are dominated by siliceous-calcareous biogenic oozes having depositional rates of 0.1 to 1.5 cm/1000 years. Conservative constituents of pore fluids showed, as have cores from other pelagic areas of the Pacific, insignificant or marginally significant changes with depth and location. However, in Sites 70 and 71, calcium, magnesium and strontium showed major shifts in concentration with depth. These changes appear to be related to recrystallization phenomena in skeletal debris of nannoplankton and to the relative accumulation rate of the sediments. The chemical anomalies increase relatively smoothly with depth, demonstrating the effectiveness of vertical diffusional communication, and apparent lack of bulk fluid movement, as noted in Leg 7 and other sites.

Quality analysis of patient information about knee arthroscopy on the World Wide Web.

PubMed

Sambandam, Senthil Nathan; Ramasamy, Vijayaraj; Priyanka, Priyanka; Ilango, Balakrishnan

2007-05-01

This study was designed to ascertain the quality of patient information available on the World Wide Web on the topic of knee arthroscopy. For the purpose of quality analysis, we used a pool of 232 search results obtained from 7 different search engines. We used a modified assessment questionnaire to assess the quality of these Web sites. This questionnaire was developed based on similar studies evaluating Web site quality and includes items on illustrations, accessibility, availability, accountability, and content of the Web site. We also compared results obtained with different search engines and tried to establish the best possible search strategy to attain the most relevant, authentic, and adequate information with minimum time consumption. For this purpose, we first compared 100 search results from the single most commonly used search engine (AltaVista) with the pooled sample containing 20 search results from each of the 7 different search engines. The search engines used were metasearch (Copernic and Mamma), general search (Google, AltaVista, and Yahoo), and health topic-related search engines (MedHunt and Healthfinder). The phrase "knee arthroscopy" was used as the search terminology. Excluding the repetitions, there were 117 Web sites available for quality analysis. These sites were analyzed for accessibility, relevance, authenticity, adequacy, and accountability by use of a specially designed questionnaire. Our analysis showed that most of the sites providing patient information on knee arthroscopy contained outdated information, were inadequate, and were not accountable. Only 16 sites were found to be providing reasonably good patient information and hence can be recommended to patients. Understandably, most of these sites were from nonprofit organizations and educational institutions. Furthermore, our study revealed that using multiple search engines increases patients' chances of obtaining more relevant information rather than using a single search engine. Our study shows the difficulties encountered by patients in obtaining information regarding knee arthroscopy and highlights the duty of knee surgeons in helping patients to identify the relevant and authentic information in the most efficient manner from the World Wide Web. This study highlights the importance of the role of orthopaedic surgeons in helping their patients to identify the best possible information on the World Wide Web.

Ecological and agriculture impacts of bakery yeast wastewater use on weed communities and crops in an arid environment.

PubMed

Abu-Dieyeh, Mohammed H; Diab, Mahmoud; Al-Ghouti, Mohammad A

2017-06-01

The goal of this study was to evaluate the impact of using yeast wastewater (YW) on weed communities. The study showed that all ecological parameters including species richness, dispersion, density, frequency, and % of vegetation cover were significantly increased in the site irrigated with YW compared to a natural rain fed site and another site irrigated with fresh water. The vegetation cover (%) was significantly increased by 2-folds in the site irrigated with YW (52%) than the one irrigated with fresh water (27%). Species richness increases to 23 in the site irrigated with yeast wastewater compared to 12 species in natural rain fed site and 7 species in areas irrigated with fresh water. The 10 studied weed species germinated better at 10 and 20% dilutions of baker's YW. However, only five species achieved few germination (3-25%) at 50% of YW and the two species Sisymbrim irio and Cardariia droba achieved (6-13%) germination using 100% YW. No germination occurred for the crop seeds (tomato, squash, lentil, and barley) at 50 and 100% YW. For tomato, 10 and 20% of YW achieved better germination (82 and 63%, respectively) than the seeds of other species, followed by barley with 80 and 53% of germination. Squash showed the lowest germination percentage with 59 and 42% at 10 and 20% of YW, respectively. Yeast wastewater seems to be crop specific and can affect weed species composition and relative abundances and care should be taken before using the effluent for irrigation of tree plantations and crops.

Attained height, sex, and risk of cancer at different anatomic sites in the NIH-AARP diet and health study.

PubMed

Kabat, Geoffrey C; Kim, Mimi Y; Hollenbeck, Albert R; Rohan, Thomas E

2014-12-01

To examine the association of adult height with risk of cancer at different anatomic sites in a cohort of men and women. The association of self-reported height with subsequent cancer risk was assessed in 288,683 men and 192,514 women enrolled in the National Institutes of Health-AARP Diet and Health Study. After a median follow-up of 10.5 years, incident cancer was diagnosed in 51,139 men and 23,407 women. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95 % confidence intervals (95 % CIs) for the association of height with cancer risk. After adjustment for covariates, height was positively associated with increased risk of all cancers combined in both men [HR10 cm increase = 1.05 (95 % CI 1.04-1.06)] and women [HR10 cm increase = 1.08 (95 % CI 1.06-1.10)]. Several sites common to men and women showed significant positive associations with height: colon, rectum, kidney, melanoma, and non-Hodgkin's lymphoma. For other shared sites, the association differed by sex. For still other sites, there was no clear association with height. Positive associations were also observed with cancers of the breast, endometrium, and prostate. Different patterns were observed in the height-cancer association by sex. Studies investigating the biological mechanisms underlying the association of height with cancer risk should focus on those sites that show a reproducible association with attained height.

Impact of prolonged storm activity on the Ecological Status of intertidal benthic habitats within oyster (Crassostrea gigas) trestle cultivation sites.

PubMed

O'Carroll, Jack P J; Quinn, Christina; Forde, James; Patterson, Adrian; O'Beirn, Francis X; Kennedy, Robert

2016-09-15

The Ecological Status (ES; sensu the Water Framework Directive) of intertidal benthic communities within six oyster trestle cultivation sites was found to be negatively impacted along the access routes to trestles in a 2013 study. All cultivation sites occur within Natura 2000 sites. The current study revisited four of the 2013 cultivation sites in February 2014 one month after the storm activity of winter 2013/14 to test if the compaction effect along access routes persisted after the storms. Three levels of the fixed factor treatment were sampled; immediately below the trestles, along the access route and 300m away from any anthropogenic activity. The compaction effect at the Access treatment persisted in spite of the major storm activity. The current study showed the IQI to be effective for assessing the impacts of aquaculture and highlights the IQI as a tool for monitoring Conservation Status of intertidal communities under the Habitats Directive. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gender in the Geosciences: Factors Supporting the Recruitment and Retention of Women in the Undergraduate Major

NASA Astrophysics Data System (ADS)

Riggs, E. M.; Sexton, J. M.; Pugh, K.; Bergstrom, C.; Parmley, R.; Phillips, M.

2014-12-01

The proportion of women earning undergraduate geoscience degrees has remained about 40% for over a decade. Little research has investigated why women select and persist in a geoscience major. This study addresses why students major in the geosciences and why some programs are more successful at recruiting and retaining female students. We collected interview and survey data from faculty and students at six public US universities. Four sites had a low proportion of female degree recipients (< 38%) and two sites had a high proportion of female degree recipients (> 48%). 408 students (64% female) completed surveys. Interviews were conducted with 49 faculty members and 151 students. Survey data analysis showed that interest/identity and transformative experiences were significant predictors of students' decision to major in geoscience. Institutional barriers and supports were significant predictors of confidence in the major while connection to instructor predicted students' intent to major. Analysis of pre- and post-course surveys show that students with a greater connection to instructors and students whose instructors expressed more passion for the content also reported higher levels of transformative experiences. This effect was especially pronounced for women and was a significant predictor of persistence in the major. Qualitative data show differences in departmental practices and climate between low and high female graduation sites. High sites used many student-centered approaches to teaching, had extensive opportunities for and a high number of undergraduate students involved in research, and had many opportunities for faculty-student interaction outside of class. Low sites had few of these practices. Qualitative data also showed differences in the gendered equity climate between high and low sites. High sites had more positive gender equity climates and low sites had more negative gender equity climates. At this time, we do not fully understand the causal relationships among all of these findings and higher female graduation rates, but this research is ongoing and these relationships are a focus of our final year of this research project.

Unbinding Pathways of an Agonist and an Antagonist from the 5-HT3 Receptor

PubMed Central

Thompson, A. J.; Chau, P.-L.; Chan, S. L.; Lummis, S. C. R.

2006-01-01

The binding sites of 5-HT3 and other Cys-loop receptors have been extensively studied, but there are no data on the entry and exit routes of ligands for these sites. Here we have used molecular dynamics simulations to predict the pathway for agonists and antagonists exiting from the 5-HT3 receptor binding site. The data suggest that the unbinding pathway follows a tunnel at the interface of two subunits, which is ∼8 Å long and terminates ∼20 Å above the membrane. The exit routes for an agonist (5-HT) and an antagonist (granisetron) were similar, with trajectories toward the membrane and outward from the ligand binding site. 5-HT appears to form many hydrogen bonds with residues in the unbinding pathway, and experiments show that mutating these residues significantly affects function. The location of the pathway is also supported by docking studies of granisetron, which show a potential binding site for granisetron on the unbinding route. We propose that leaving the binding pocket along this tunnel places the ligands close to the membrane and prevents their immediate reentry into the binding pocket. We anticipate similar exit pathways for other members of the Cys-loop receptor family. PMID:16387779

The Impact of Trampling on Reef Macrobenthos in Northeastern Brazil: How Effective are Current Conservation Strategies?

NASA Astrophysics Data System (ADS)

Santos, Gleice S.; Burgos, Douglas C.; Lira, Simone M. A.; Schwamborn, Ralf

2015-10-01

Tropical reefs are used for intensive tourism in various parts of the world. However, few studies have investigated the effect of regular trampling on these fragile ecosystems. The aim of this study was to assess the effect of different conservation strategies (open access, partial protection, and total long-term closure) on intertidal reef tops in Porto de Galinhas and Tamandaré, Pernambuco State, Brazil. Analysis of the macrobenthic community was performed with photo transects and image analysis (CPCe). Twenty-seven transects were surveyed from January to August 2012, in intensively impacted (I) open-access sites, in partially protected (P) sites with occasional, illegal trampling, and in a permanently closed (C) site. In I sites, total live cover was half the cover found in adjacent P sites. The area of bare rock averaged 53.6 and 25.0 % in I and P sites, respectively. In the C site, the area of bare rock was only 19.8 %. In I and P sites, macroalgae ( Palisada perforata) were dominating, while in the C site, the zoanthid Zoanthus sociatus was most abundant. Shell-bearing vermetids ( Petaloconchus varians) and bivalves ( Isognomon bicolor) were more abundant at the C site, being possible bioindicators for areas with zero or little trampling. Twelve years of total closure produced near-pristine communities in the C site, dominated by zoanthids and fragile mollusks. This study showed that trampling has severe and long-lasting consequences for the structure of these ecosystems.

The Impact of Trampling on Reef Macrobenthos in Northeastern Brazil: How Effective are Current Conservation Strategies?

PubMed

Santos, Gleice S; Burgos, Douglas C; Lira, Simone M A; Schwamborn, Ralf

2015-10-01

Tropical reefs are used for intensive tourism in various parts of the world. However, few studies have investigated the effect of regular trampling on these fragile ecosystems. The aim of this study was to assess the effect of different conservation strategies (open access, partial protection, and total long-term closure) on intertidal reef tops in Porto de Galinhas and Tamandaré, Pernambuco State, Brazil. Analysis of the macrobenthic community was performed with photo transects and image analysis (CPCe). Twenty-seven transects were surveyed from January to August 2012, in intensively impacted (I) open-access sites, in partially protected (P) sites with occasional, illegal trampling, and in a permanently closed (C) site. In I sites, total live cover was half the cover found in adjacent P sites. The area of bare rock averaged 53.6 and 25.0% in I and P sites, respectively. In the C site, the area of bare rock was only 19.8%. In I and P sites, macroalgae (Palisada perforata) were dominating, while in the C site, the zoanthid Zoanthus sociatus was most abundant. Shell-bearing vermetids (Petaloconchus varians) and bivalves (Isognomon bicolor) were more abundant at the C site, being possible bioindicators for areas with zero or little trampling. Twelve years of total closure produced near-pristine communities in the C site, dominated by zoanthids and fragile mollusks. This study showed that trampling has severe and long-lasting consequences for the structure of these ecosystems.

Unemployment in chronic airflow obstruction around the world: results from the BOLD study.

PubMed

Grønseth, Rune; Erdal, Marta; Tan, Wan C; Obaseki, Daniel O; Amaral, Andre F S; Gislason, Thorarinn; Juvekar, Sanjay K; Koul, Parvaiz A; Studnicka, Michael; Salvi, Sundeep; Burney, Peter; Buist, A Sonia; Vollmer, William M; Johannessen, Ane

2017-09-01

We aimed to examine associations between chronic airflow obstruction (CAO) and unemployment across the world.Cross-sectional data from 26 sites in the Burden of Obstructive Lung Disease (BOLD) study were used to analyse effects of CAO on unemployment. Odds ratios for unemployment in subjects aged 40-65 years were estimated using a multilevel mixed-effects generalised linear model with study site as random effect. Site-by-site heterogeneity was assessed using individual participant data meta-analyses.Out of 18 710 participants, 11.3% had CAO. The ratio of unemployed subjects with CAO divided by subjects without CAO showed large site discrepancies, although these were no longer significant after adjusting for age, sex, smoking and education. The site-adjusted odds ratio (95% CI) for unemployment was 1.79 (1.41-2.27) for CAO cases, decreasing to 1.43 (1.14-1.79) after adjusting for sociodemographic factors, comorbidities and forced vital capacity. Of other covariates that were associated with unemployment, age and education were important risk factors in high-income sites (4.02 (3.53-4.57) and 3.86 (2.80-5.30), respectively), while female sex was important in low- to middle-income sites (3.23 (2.66-3.91)).In the global BOLD study, CAO was associated with increased levels of unemployment, even after adjusting for sociodemographic factors, comorbidities and lung function. Copyright ©ERS 2017.

Foredune Classification and Storm Response: Automated Analysis of Terrestrial Lidar DEMs

DTIC Science & Technology

2015-06-15

since Hurricane Sandy. 041 20/3/2015 4 Figure 1. A. The study site in Duck , NC showing the alongshore coordinates of the local coordinate...waves on March 10: Hs = 4.8 m at 16 sec Coastal Lidar and Radar Imaging System (CLARIS) Nor’easter Storm Conditions Study Site: Duck , NC...Engineer Research and Development Center, Coastal & Hydraulics Laboratory, Coastal Observation & Analysis Branch, 1261 Duck Rd, Duck , NC 27949, USA

Precolombian settlements in French Guiana : geoarchaeological approach toward a new understanding of the human impact on landscape.

NASA Astrophysics Data System (ADS)

Brancier, J.; Cammas, C.; Todisco, D.; Fouache, E.

2012-04-01

Recent archaeological research in French Guiana conducted by INRAP (Institut National de Recherches Archéologiques Préventives), specifically in the Couac Program (Cirad, Inra, Inrap) revealed precolombian settlements on different geomorphic contexts like coastal and fluvial areas, as is seen in Brazil, but also what seems to be quite a dense occupation on higher grounds (mounds). Most of the times, the excavation shows cultural remains like pottery, archaeological pits and ditches, as well as sediments that are described by the archaeologists as "thick and dark-coloured layers". In Brazil, dark layers found in archaeological sites are called Terra Preta do Indio or Amazonian Dark Earth (ADE), and their study is thought necessary to explain and understand ancient human settlement. In Brazil, geoarchaeological methods as well as chemical analyses, pedology and micromorphology helped to describe ADE and understand their archaeological potential and characteristics. In order to better understand the French Guiana dark layers, we studied two sites from the estuarine zone of the lower Maroni River (Surinam border) (Chemin Saint Louis and Balaté at Saint Laurent du Maroni), and two ring-ditched hilltop sites, on ferralsols, in the interfluvial forest area ("Montagnes Couronnées" in French) (MC 87 et 88, near Regina). Regarding Brazilians research on ADE, we described for the first time the archaeological stratigraphy of French Guiana ancient settlement using a geoarchaeological approach combining biogeochemistry, pedology in correlation with micromorphological analyses. Our first results show that dark layers from archaeological sites studied are very different from natural soils underneath in the estuarine zone. Although, the pH is quite low, micromorphological analyses show clay coatings in the alluvial terrace before human settlement. These analyses also show more organic matter and charcoals in the archaeological layers than beneath, and very large amounts of phytolithes, that give to botanists a new way of research. Due to either the acid context and / or to the ancient lifestyle, very few bones were found. We also found geochemical and micromorphological differences between the sites in the estuarine zone or in forest area. First geoarchaeological results give information about the nature of the sites, and suggest that French Guiana dark layers have original properties. We therefore suggest, in accordance with the archaeologist team, to call them Guianan Dark Earth (GDE). If we compare the GDE of this study with data from bibliographic review on ADE, micromorphological analyses show that GDE presents less anthropogenic components than ADE. Chemical analyses also show differences between GDE and ADE, like pH and available nutrients, lower in estuarine GDE. These differences suggested that GDE can have different properties than those of ADE, but are nonetheless part of the archaeological soils of the Amazonian basin.

Unusual Structure of the attB Site of the Site-Specific Recombination System of Lactobacillus delbrueckii Bacteriophage mv4

PubMed Central

Auvray, Frédéric; Coddeville, Michèle; Ordonez, Romy Catoira; Ritzenthaler, Paul

1999-01-01

The temperate phage mv4 integrates its genome into the chromosome of Lactobacillus delbrueckii subsp. bulgaricus by site-specific recombination within the 3′ end of a tRNASer gene. Recombination is catalyzed by the phage-encoded integrase and occurs between the phage attP site and the bacterial attB site. In this study, we show that the mv4 integrase functions in vivo in Escherichia coli and we characterize the bacterial attB site with a site-specific recombination test involving compatible plasmids carrying the recombination sites. The importance of particular nucleotides within the attB sequence was determined by site-directed mutagenesis. The structure of the attB site was found to be simple but rather unusual. A 16-bp DNA fragment was sufficient for function. Unlike most genetic elements that integrate their DNA into tRNA genes, none of the dyad symmetry elements of the tRNASer gene were present within the minimal attB site. No inverted repeats were detected within this site either, in contrast to the lambda site-specific recombination model. PMID:10572145

Diversity patterns and composition of native and exotic floras in central Chile

NASA Astrophysics Data System (ADS)

Figueroa, Javier A.; Teillier, Sebastián; Castro, Sergio A.

2011-03-01

Floristic changes in the Mediterranean region of central Chile brought about by human impact appear to be shared with other climatic regions, although there is a notable absence of empirical studies and available quantitative evidence for the central Chile region. This study examines the cover, richness and composition of native and exotic plant species in a representative area of central Chile. Through floristic characterization of 33 sites sampled using 40 × 40 m plots distributed along transect on which the two farthest sites were separated by 50 km, the floristic richness and cover patterns, as well as the general land use characteristics were evaluated (native matorral, espinal, abandoned farming field, forest plantations, periurban sites, road sites, river bank, and burnt site). We recorded 327 species of plants; 213 species were native and 114 were exotic. The average number of species was heterogeneous in all sites, showing a greater relative native frequency in those sites with a lower level of anthropic intervention. Except for the matorral, the cover of exotic species was greater than that of native species. No relation was found between richness and cover in relation to the different types of land use. The relationship between cover of native and exotic was negative, although for richness did not show relationship. Results show that the exotic species are limited by resources, although they have not completely displaced the native species. The native and exotic floras respond to different spatial distribution patterns, so their presence makes it possible to establish two facts rarely quantified in central Chile: first, that the exotic flora replaces (but does not necessarily displace) the native flora, and second, that at the same time, because of its greater geographic ubiquity and the abundance levels that it achieves, it contributes to the taxonomic and physiognomic homogenization of central Chile.

Assessing the legacy effects of historic charcoal production in Brandenburg, Germany

NASA Astrophysics Data System (ADS)

Schneider, Anna; Hirsch, Florian; Raab, Alexandra; Bonhage, Alexander; Raab, Thomas

2017-04-01

Charcoal produced in kilns or hearths was an important source of energy in many regions of Europe and Northern America until the 19th century, and charcoal production in hearths is still common in many other regions of the world. The remains of charcoal hearths are therefore a widespread legacy of historic land use in forest areas. Soils on charcoal hearth sites are characterized by a technogenic layer rich in charcoal and ash on top of the soil profile, and by a pyrogenic modification of substrates below the former hearth. The aims of our study are to examine how these alterations to the natural soil profiles affect the soil water regime and other soil physical properties, and to assess the relevance of these effects on the landscape scale. We present first results of a mapping of hearth site occurrence in forest areas in the state of Brandenburg, Germany, and of a characterization of the infiltration behaviour on hearth sites as compared with undisturbed forest soils. Results of mapping small-scale relief features from LIDAR-based digital elevation models show that charcoal hearths occur in a high density in many large forest areas throughout Brandenburg. In the areas studied so far, up to almost 3% of the soil surface were found to be affected by the remains of historic hearths. First analyses of soil physical properties indicate differences in the infiltration characteristics of hearth site soils and undisturbed forest soils: Hood infiltrometer measurements show a very high spatial variability of hydraulic conductivity for hearth site soils, and water-drop-penetration-time tests reflect extremely high hydrophobicity of the technogenic layer on the sites. Results of dye tracer experiment show considerably strong preferential flow and therefore a higher spatial variability of soil wetness below the hearth remains. Overall, our first results therefore indicate that the legacy effects of historic charcoal production might significantly affect overall site conditions in forest areas with a high density of charcoal hearth remains.

Soft tissue graft interference fit fixation: observations on graft insertion site healing and tunnel remodeling 2 years after ACL reconstruction in sheep.

PubMed

Hunt, Patrick; Rehm, Oliver; Weiler, Andreas

2006-12-01

Using soft tissue grafts for anterior cruciate ligament (ACL) reconstruction, insertion site healing plays a crucial role in the long-term fate of the graft. It has been shown in an experimental animal study that using a soft tissue graft and anatomic graft fixation, a direct ligamentous insertion alike the native ACL developed 24 weeks postoperatively. Yet there are no reports on the long-term insertion site healing of anatomically fixed soft tissue grafts. The objective of this study was to evaluate graft insertion site healing, the intra-tunnel fate of the graft and its osseous replacement 2 years after ACL reconstruction in sheep. The left ACLs of six sheep were replaced by an autologous flexor tendon split graft and anatomically fixed with biodegradable poly-(D, L-lactide) interference screws. Animals received polychromic sequential labeling at different points in time to determine bone apposition per period. For evaluation of the insertion site healing and intra-tunnel changes, MRI scans were taken in vivo. Following sacrifice, radiographic imaging, conventional histology and fluorescence microscopy was undertaken. Most of the specimens showed a wide direct ligamentous insertion. It showed patterns alike the direct ligament insertion seen in intact ACLs. The intra-tunnel part of the graft had completely lost its tendon-like structure and in two cases, it was separated from the graft insertion by a thick bony layer. The biodegradable interference screw was fully degraded in all specimens. Ossification of the former drill tunnels was intense, showing only partial-length tunnel remnants in one femoral and three tibial specimens. As the graft heals to the joint surface and the aperture site is closed with soft tissue, mechanical stress of the intra-tunnel part of the graft is eliminated and the bone tunnel is protected from synovial fluid, resulting in osseous bridging of the tunnel aperture site, accelerated intra-tunnel graft resorption and its osseous replacement.

Macrophage inflammatory protein-1α shows predictive value as a risk marker for subjects and sites vulnerable to bone loss in a longitudinal model of aggressive periodontitis.

PubMed

Fine, Daniel H; Markowitz, Kenneth; Fairlie, Karen; Tischio-Bereski, Debbie; Ferrandiz, Javier; Godboley, Dipti; Furgang, David; Gunsolley, John; Best, Al

2014-01-01

Improved diagnostics remains a fundamental goal of biomedical research. This study was designed to assess cytokine biomarkers that could predict bone loss (BL) in localized aggressive periodontitis. 2,058 adolescents were screened. Two groups of 50 periodontally healthy adolescents were enrolled in the longitudinal study. One group had Aggregatibacter actinomycetemcomitans (Aa), the putative pathogen, while the matched cohort did not. Cytokine levels were assessed in saliva and gingival crevicular fluid (GCF). Participants were sampled, examined, and radiographed every 6 months for 2-3 years. Disease was defined as radiographic evidence of BL. Saliva and GCF was collected at each visit, frozen, and then tested retrospectively after detection of BL. Sixteen subjects with Aa developed BL. Saliva from Aa-positive and Aa-negative healthy subjects was compared to subjects who developed BL. GCF was collected from 16 subjects with BL and from another 38 subjects who remained healthy. GCF from BL sites in the 16 subjects was compared to healthy sites in these same subjects and to healthy sites in subjects who remained healthy. Results showed that cytokines in saliva associated with acute inflammation were elevated in subjects who developed BL (i.e., MIP-1α MIP-1β IL-α, IL-1β and IL-8; p<0.01). MIP-1α was elevated 13-fold, 6 months prior to BL. When MIP-1α levels were set at 40 pg/ml, 98% of healthy sites were below that level (Specificity); whereas, 93% of sites with BL were higher (Sensitivity), with comparable Predictive Values of 98%; p<0.0001; 95% C.I. = 42.5-52.7). MIP-1α consistently showed elevated levels as a biomarker for BL in both saliva and GCF, 6 months prior to BL. MIP-1α continues to demonstrate its strong candidacy as a diagnostic biomarker for both subject and site vulnerability to BL.

Assessing the proposed pre-last glacial maximum human occupation of North America at Coats-Hines-Litchy, Tennessee, and other sites

NASA Astrophysics Data System (ADS)

Tune, Jesse W.; Waters, Michael R.; Schmalle, Kayla A.; DeSantis, Larisa R. G.; Kamenov, George D.

2018-04-01

Genomic studies indicate that the first Pleistocene foragers who entered North America diverged from ancestral populations in Beringia sometime after the Last Glacial Maximum (LGM); however, several archaeological sites in North America have been proposed to predate the LGM. We present the results of our excavation and analysis of one such site, Coats-Hines-Litchy, Tennessee, which show that this site is a paleontological locality containing a geofact assemblage that pre-dates the LGM. Other sites in North America that purportedly predate the LGM occur in geomorphic contexts that are also conducive to the formation of geofact assemblages. As such, we propose that the reported artifacts from these sites were created by natural processes. No sites in North America currently provide credible evidence of a pre-LGM occupation.

The effects of marine sand and gravel extraction on the sediment composition and macrofaunal community of a commercial dredging site (15 years post-dredging).

PubMed

Waye-Barker, Georgia A; McIlwaine, Paul; Lozach, Sophie; Cooper, Keith M

2015-10-15

A prediction that faunal recovery of a marine aggregate extraction site subjected to high dredging intensity was likely to take 15-20 years was investigated. Samples were collected at the high dredging intensity site and two reference sites in 2011 (15 years post-dredging). Results indicated that the high site had similar sediment characteristics to the reference sites by 2011. Macrofaunal data analyses showed no difference between the values of all calculated univariate measures (abundance, number of taxa, biomass and evenness) between the high and reference sites. Multivariate analyses found that the macrofaunal community at the high site was comparable to those of the reference sites by 2011. Overall, the results supported the predicted recovery time. The findings of the study suggest that persistent physical impacts prolonged the biological recovery of the high site. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Secondary production of the fiddler crab Uca rapax from mangrove areas under anthropogenic eutrophication in the Western Atlantic, Brazil.

PubMed

Costa, Tarso de M M; Soares-Gomes, Abilio

2015-12-30

Fiddler crabs Uca rapax were analyzed in three mangrove areas located in both a lagoon and estuarine system in order to study the influence of eutrophication on their population dynamics and production. Populations at the three sites showed a biased sex ratio. Densities were similar at the three sites, but biomass was higher at the lagoon system. Despite biomass being higher at the most eutrophic site, this site exhibited the lowest production. Regarding age structure, the population inhabiting the less eutrophic site mainly comprised younger crabs. The lower production and smaller P/B ratio found in the more eutrophic site were most likely consequences of a high mortality rate and an aged population. Our study evidences the high plasticity of the fiddler crab U. rapax, and confirms secondary production and P/B ratio estimates as useful tools to assess the effects of environmental change. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impact of heavy metal on activity of some microbial enzymes in the riverbed sediments: Ecotoxicological implications in the Ganga River (India).

PubMed

Jaiswal, Deepa; Pandey, Jitendra

2018-04-15

We studied the extracellular enzyme activity (EEA) in the riverbed sediment along a 518km gradient of the Ganga River receiving carbon and nutrient load from varied human sources. Also, we tested, together with substrate-driven stimulation, if the heavy metal accumulated in the sediment inhibits enzyme activities. Because pristine values are not available, we considered Dev Prayag, a least polluted site located 624km upstream to main study stretch, as a reference site. There were distinct increases in enzyme activities in the sediment along the study gradient from Dev Prayag, however, between-site differences were in concordance with sediment carbon(C), nitrogen (N) and phosphorus (P). Fluorescein diacetate hydrolysis (FDAase), β-glucosidase (Glu) and protease activities showed positive correlation with C, N and P while alkaline phosphatase was found negatively correlated with P. Enzyme activities were found negatively correlated with heavy metal, although ecological risk index (E R i ) varied with site and metal species. Dynamic fit curves showed significant positive correlation between heavy metal and microbial metabolic quotient (qCO 2 ) indicating a decrease in microbial activity in response to increasing heavy metal concentrations. This study forms the first report linking microbial enzyme activities to regional scale sediment heavy metal accumulation in the Ganga River, suggests that the microbial enzyme activities in the riverbed sediment were well associated with the proportion of C, N and P and appeared to be a sensitive indicator of C, N and P accumulation in the river. Heavy metal accumulated in the sediment inhibits enzyme activities, although C rich sediment showed relatively low toxicity due probably to reduced bioavailability of the metal. The study has relevance from ecotoxicological as well as from biomonitoring perspectives. Copyright © 2017 Elsevier Inc. All rights reserved.

Integrating Monitoring and Genetic Methods To Infer Historical Risks of PCBs and DDE to Common and Roseate Terns Nesting Near the New Bedford Harbor Superfund Site (Massachusetts, USA)

EPA Science Inventory

Common and roseate terns are migratory piscivorous seabirds with major breeding colonies within feeding range of thepolychlorinated biphenyl (PCB)-contaminated New Bedford Harbor (NBH, MA, USA) Superfund site. Our longitudinal study shows that before PCB discharges into NBH cease...

Double layer zinc-UDP coordination polymers: structure and properties.

PubMed

Qiu, Qi-Ming; Gu, Leilei; Ma, Hongwei; Yan, Li; Liu, Minghua; Li, Hui

2018-05-17

A homochiral Zn-UDP coordination polymer with an alternating parallel ABAB sequence was constructed and studied by X-ray single crystal diffraction analysis. Its crystal structure shows that there are potentially open sites in the 2D layers. The activation of the sites makes the coordination polymer a fluorescent sensor for novel heterogeneous detection of amino acids.

Satisfiers and Dissatisfiers: A Two-Factor Model for Website Design and Evaluation.

ERIC Educational Resources Information Center

Zhang, Ping; von Dran, Gisela M.

2000-01-01

Investigates Web site design factors and their impact from a theoretical perspective. Presents a two-factor model that can guide Web site design and evaluation. According to the model, there are two types of design factors: hygiene and motivator. Results showed that the two-factor model provides a means for Web-user interface studies. Provides…

The distribution and extent of heavy metal accumulation in song sparrows along Arizona's upper Santa Cruz River

USGS Publications Warehouse

Lester, Michael B.; van Riper, Charles

2014-01-01

Heavy metals are persistent environmental contaminants, and transport of metals into the environment poses a threat to ecosystems, as plants and wildlife are susceptible to long-term exposure, bioaccumulation, and potential toxicity. We investigated the distribution and cascading extent of heavy metal accumulation in southwestern song sparrows (Melospiza melodia fallax), a resident riparian bird species that occurs along the US/Mexico border in Arizona’s upper Santa Cruz River watershed. This study had three goals: (1) quantify the degree of heavy metal accumulation in sparrows and determine the distributional patterns among study sites, (2) compare concentrations of metals found in this study to those found in studies performed prior to a 2009 international wastewater facility upgrade, and (3) assess the condition of song sparrows among sites with differing potential levels of exposure. We examined five study sites along with a reference site that reflect different potential sources of contamination. Body mass residuals and leukocyte counts were used to assess sparrow condition. Birds at our study sites typically had higher metal concentrations than birds at the reference site. Copper, mercury, nickel, and selenium in song sparrows did exceed background levels, although most metals were below background concentrations determined from previous studies. Song sparrows generally showed lower heavy metal concentrations compared to studies conducted prior to the 2009 wastewater facility upgrade. We found no cascading effects as a result of metal exposure.

Amazon peatlands: quantifying ecosytem's stocks, GHG fluxes and their microbial connections

NASA Astrophysics Data System (ADS)

Cadillo-Quiroz, Hinsby; Lähteenoja, Outi; Buessecker, Steffen; van Haren, Joost

2017-04-01

Reports of hundreds of peatlands across basins in the West and Central Amazon suggest they play an important, previously not considered regional role in organic carbon (OC) and GHG dynamics. Amazon peatlands store ˜3-6 Gt of OC in their waterlogged soils with strong potential for conversion and release of GHG, in fact our recent, and others', efforts have confirmed variable levels of GHG emissions (CO2, N2O, CH4), as well as variable microbial communities across rich to poor soil peatlands. Here, we report early results of quantification of different components making up the aboveground C stocks, the rates and paths for GHG release, and microbial organisms occurring in three ecologically distinct peatland types in the Pastaza-Marañon region of the Peruvian Amazon. Evaluations were done in duplicated continuous monitoring plots established since 2015 at a "palm swamp" (PS), poor "pole forest" (pPF) and a rich "forested" (rF) peatlands. Although overall vegetation "structure" with a few dominant plus several low frequency species was common across the three sites, their botanical composition and tree density was highly contrasting. Aboveground C stocks content showed the following order among sites: rF>PS>pPF, and hence we tested whether this differences can have a direct effect on CH4 emissions rates. CH4 emissions rates from soils were observed in average at 11, 6, and 0.8 mg-C m-2 h-1for rF, PS, and pPF respectively. However, these estimated fluxes needed to be revised when we develop quantifications of CH4 emissions from tree stems. Tree stem fluxes were detected showing a broad variation with nearly nill emissions in some species all the way to maximum fluxes near to ˜90 mg-C m-2 h-1 in other species. Mauritia flexuosa, a highly dominant palm species in PS and ubiquitous to the region, showed the highest ranges of CH4 flux. In the PS site, overall CH4 flux estimate increased by ˜50% when including stem emission weighted by trees' species, density and heights. Flux estimates in p PF did not had a significant change. Analysis across species in the study sites, plus other satellite sites, suggest that in sites stem flux emissions might be conserved with some genera in the Aracaceae, Euphorbiaceae, and Sapotaceae families showing a large emitters capacity. Further characterization also showed that CH4 flux emission from the stems decreases generally with height, suggesting a diffusion constrained stem flux, which seems limited by soil CH4 concentration and wood density. Finally, microbial community composition and methanogenic activity also showed contrasting patterns across sites, with pH being one of the major determinants. GHG producing organisms were detected in different proportions and types across study sites, and importantly methanogenic Archaea closely tracked observed differences of CH4 flux among sites. Nevertheless, the link between vegetation type and density still remain under assessment in our efforts

Effects of protonation state of Asp181 and position of active site water molecules on the conformation of PTP1B.

PubMed

Ozcan, Ahmet; Olmez, Elif Ozkirimli; Alakent, Burak

2013-05-01

In protein tyrosine phosphatase 1B (PTP1B), the flexible WPD loop adopts a closed conformation (WPDclosed ) in the active state of PTP1B, bringing the catalytic Asp181 close to the active site pocket, while WPD loop is in an open conformation (WPDopen ) in the inactive state. Previous studies showed that Asp181 may be protonated at physiological pH, and ordered water molecules exist in the active site. In the current study, molecular dynamics simulations are employed at different Asp181 protonation states and initial positions of active site water molecules, and compared with the existing crystallographic data of PTP1B. In WPDclosed conformation, the active site is found to maintain its conformation only in the protonated state of Asp181 in both free and liganded states, while Asp181 is likely to be deprotonated in WPDopen conformation. When the active site water molecule network that is a part of the free WPDclosed crystal structure is disrupted, intermediate WPD loop conformations, similar to that in the PTPRR crystal structure, are sampled in the MD simulations. In liganded PTP1B, one active site water molecule is found to be important for facilitating the orientation of Cys215 and the phosphate ion, thus may play a role in the reaction. In conclusion, conformational stability of WPD loop, and possibly catalytic activity of PTP1B, is significantly affected by the protonation state of Asp181 and position of active site water molecules, showing that these aspects should be taken into consideration both in MD simulations and inhibitor design. Copyright © 2013 Wiley Periodicals, Inc.

Mesembrinellinae (Diptera: Calliphoridae) to edge effects in the Tinguá Biological Reserve, Rio de Janeiro, Brazil.

PubMed

Gadelha, B Q; Silva, A B; Ferraz, A C P; Aguiar, V M

2015-11-01

In this study we describe the diversity of Mesembrinelinae in a biological reserve in the city of Nova Iguaçu, State of Rio de Janeiro. Traps containing sardines were distributed seasonally, at four sites: Site A (22° 58.788' S, 43° 43.459' W), in a forest edge, and sites B (22° 58.523' S, 43° 44.540' W), C (22° 58.350' S, 43° 44.678' W), and D (22° 34.865' S, 43° 27.063' W), located 1,000 m, 500 m, and 2,000 m respectively, inwards from the edge. A total of 2,150 individuals of Mesembrinellinae were collected, representing ten species. Laneela nigripes Guimarães, 1977 was the most abundant species, followed by Mesembrinella bellardiana Aldrich, 1922, Eumesembrinella cyaneicincta (Surcouf, 1919) and Mesembrinella semihyalina Mello, 1967. These species were common and constant during the study period. Mesembrinella batesi Aldrich, 1922, Eumesembrinella quadrilineata (Fabricius, 1805) and Huascaromusca aeneiventris (Wiedmann, 1830) were the less abundant flies, being considered rare and accidental. Eumesembrinella besnoiti (Seguy, 1925) was rare and accessory. Eumesembrinella cyaneicincta, M. bellardiana, M. semihyalina and M. bicolor were mostly collected in site B, while L. nigripes was mostly collected in site C. The edge effect was not evident since the four sites showed similar populations. Site B showed a strong positive relationship between abundance and richness, in site C the correlation was positive and weak, and there was no correlation in A and D. The highest abundance of specimens was recorded during autumn and winter. These flies occurred from the edge up to 2,000 m inside the forest.

Predictors of sexual coercion against women and men: a multilevel, multinational study of university students.

PubMed

Hines, Denise A

2007-06-01

Several explanations have been forwarded to account for sexual coercion in romantic relationships. Feminist theory states that sexual coercion is the result of male dominance over women and the need to maintain that dominance; however, studies showing that women sexually coerce men point towards weaknesses in that theory. Some researchers have, therefore, suggested that it is the extent to which people view the other gender as hostile that influences these rates. Furthermore, much research suggests that a history of childhood sexual abuse is a strong risk factor for later sexual victimization in relationships. Few researchers have empirically evaluated the first two explanations and little is known about whether sexual revictimization operates for men or across cultures. In this study, hierarchical linear modeling was used to investigate whether the status of women and adversarial sexual beliefs predicted differences in sexual coercion across 38 sites from around the world, and whether sexual revictimization operated across genders and cultures. Participants included 7,667 university students from 38 sites. Results showed that the relative status of women at each site predicted significant differences in levels of sexual victimization for men, in that the greater the status of women, the higher the level of forced sex against men. In addition, differences in adversarial sexual beliefs across sites significantly predicted both forced and verbal sexual coercion for both genders, such that greater levels of hostility towards women at a site predicted higher levels of forced and verbal coercion against women and greater levels of hostility towards men at a site predicted higher levels of forced and verbal coercion against men. Finally, sexual revictimization occurred for both genders and across all sites, suggesting that sexual revictimization is a cross-gender, cross-cultural phenomenon. Results are discussed in terms of their contributions to the literature, limitations of the current study, and suggestions for future research.

Spatial and temporal variation of sources contributing to quasi-ultrafine particulate matter PM0.36 in Augsburg, Germany.

PubMed

Li, Fengxia; Schnelle-Kreis, Jürgen; Cyrys, Josef; Wolf, Kathrin; Karg, Erwin; Gu, Jianwei; Orasche, Jürgen; Abbaszade, Gülcin; Peters, Annette; Zimmermann, Ralf

2018-08-01

to study the sources contributing to quasi-ultrafine particle (UFP) organic carbon and the spatial temporal variability of the sources. 24h quasi-UFP (particulate matter <0.36μm in this study) was sampled at a reference site continuously and at one of 5 other sites (T1, T2, T3, T4 and B1) in parallel in Augsburg, Germany from April 11th, 2014 to February 22nd, 2015, attempting to conduct 2-week campaigns at each site in 3 different seasons. Positive matrix factorization (PMF) was applied to measured organic tracers for source apportionment analyses. Pearson correlation coefficient r and coefficient of divergence (COD) were calculated to investigate spatial temporal variation of source contributions. 5 sources were identified comprising biomass burning (BB), traffic emissions (Traffic), biogenic secondary organic aerosol (bioSOA), isoprene originated secondary organic aerosol (isoSOA) and biomass burning related secondary organic aerosol (bbSOA). In general, good temporal correlation and uniform distribution within the study area are found for bioSOA and bbSOA, probably resulting from regional formation/transport. Lower temporal correlation and spatial heterogeneity of isoSOA were found at the city background site with local influence from green space and less traffic impact. BB demonstrated very good temporal correlation, but higher contributions at sites influenced by local residential heating emissions were observed. Traffic showed the least seasonality and lower correlation over time among the sources. However, it demonstrated low spatial heterogeneity of absolute contribution, and only a few days of elevated contribution was found at T3 when wind came directly from the street nearby. temporal correlation and spatial variability of sources contributing to the organic fraction of quasi-UFP vary among sites and source types and show source-specific characteristics. Therefore, caution should be taken when using one monitor site measurement to assess human exposure in health effect studies of quasi-UFP. Copyright © 2018 Elsevier B.V. All rights reserved.

Shared regulatory sites are abundant in the human genome and shed light on genome evolution and disease pleiotropy.

PubMed

Tong, Pin; Monahan, Jack; Prendergast, James G D

2017-03-01

Large-scale gene expression datasets are providing an increasing understanding of the location of cis-eQTLs in the human genome and their role in disease. However, little is currently known regarding the extent of regulatory site-sharing between genes. This is despite it having potentially wide-ranging implications, from the determination of the way in which genetic variants may shape multiple phenotypes to the understanding of the evolution of human gene order. By first identifying the location of non-redundant cis-eQTLs, we show that regulatory site-sharing is a relatively common phenomenon in the human genome, with over 10% of non-redundant regulatory variants linked to the expression of multiple nearby genes. We show that these shared, local regulatory sites are linked to high levels of chromatin looping between the regulatory sites and their associated genes. In addition, these co-regulated gene modules are found to be strongly conserved across mammalian species, suggesting that shared regulatory sites have played an important role in shaping human gene order. The association of these shared cis-eQTLs with multiple genes means they also appear to be unusually important in understanding the genetics of human phenotypes and pleiotropy, with shared regulatory sites more often linked to multiple human phenotypes than other regulatory variants. This study shows that regulatory site-sharing is likely an underappreciated aspect of gene regulation and has important implications for the understanding of various biological phenomena, including how the two and three dimensional structures of the genome have been shaped and the potential causes of disease pleiotropy outside coding regions.

A spring window for geobotanical anomaly detection

NASA Technical Reports Server (NTRS)

Bell, R.; Labovitz, M. L.; Masuoka, E. J.

1985-01-01

The observation of senescence of deciduous vegetation to detect soil heavy metal mineralization is discussed. A gridded sampling of two sites of Quercus alba L. in south-central Virginia in 1982 is studied. The data reveal that smaller leaf blade lengths are observed in the soil site with copper, lead, and zinc concentrations. A random study in 1983 of red and white Q. rubra L., Q. prinus L., and Acer rubrum L., to confirm previous results is described. The observations of blade length and bud breaks show a 7-10 day lag in growth in the mineral site for the oak trees; however, the maple trees are not influenced by the minerals.

Five parameters for the evaluation of the soil nonlinearity during the Ms8.0 Wenchuan Earthquake using the HVSR method

NASA Astrophysics Data System (ADS)

Ren, Yefei; Wen, Ruizhi; Yao, Xinxin; Ji, Kun

2017-08-01

The consideration of soil nonlinearity is important for the accurate estimation of the site response. To evaluate the soil nonlinearity during the 2008 Ms8.0 Wenchuan Earthquake, 33 strong-motion records obtained from the main shock and 890 records from 157 aftershocks were collected for this study. The horizontal-to-vertical spectral ratio (HVSR) method was used to calculate five parameters: the ratio of predominant frequency (RFp), degree of nonlinearity (DNL), absolute degree of nonlinearity (ADNL), frequency of nonlinearity (fNL), and percentage of nonlinearity (PNL). The purpose of this study was to evaluate the soil nonlinearity level of 33 strong-motion stations and to investigate the characteristics, performance, and effective usage of these five parameters. Their correlations with the peak ground acceleration (PGA), peak ground velocity (PGV), average uppermost 30-m shear-wave velocity ( V S30), and maximum amplitude of HVSR ( A max) were investigated. The results showed that all five parameters correlate well with PGA and PGV. The DNL, ADNL, and PNL also show a good correlation with A max, which means that the degree of soil nonlinearity not only depends on the ground-motion amplitude (e.g., PGA and PGV) but also on the site condition. The fNL correlates with PGA and PGV but shows no correlation with either A max or V S30, implying that the frequency width affected by the soil nonlinearity predominantly depends on the ground-motion amplitude rather than the site condition. At 16 of the 33 stations analyzed in this study, the site response showed evident (i.e., strong and medium) nonlinearity during the main shock of the Wenchuan Earthquake, where the ground-motion level was almost beyond the threshold of PGA > 200 cm/s2 or PGV > 15 cm/s. The site response showed weak and no nonlinearity at the other 14 and 3 stations. These results also confirm that RFp, DNL, ADNL, and PNL are effective in identifying the soil nonlinearity behavior. The identification results vary for different parameters because each parameter has individual features. The performance of the PNL was better than that of DNL and ADNL in this case study. The thresholds of ADNL and PNL are proposed to be 2.0 and 7%, respectively.[Figure not available: see fulltext.

Population dose commitments due to radioactive releases from nuclear power plant sites in 1987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1987. Fifty-year dose commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 70 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for reach of the sites is a histogram showing the fraction of the total population within 2 to 80 kmmore » around each site receiving various average dose commitments from the airborne pathways. The site average individual dose commitment from all pathways ranged from a low of 2 {times} 10{sup {minus}6} mrem to a high of 0.009 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites. However, licensee calculation of doses to the maximally exposed individual at some sites indicated values of up to approximately 100 times average individual doses (on the order of a few millirem per year). 2 refs., 2 figs., 7 tabs.« less

Prediction of Protein Modification Sites of Pyrrolidone Carboxylic Acid Using mRMR Feature Selection and Analysis

PubMed Central

Zheng, Lu-Lu; Niu, Shen; Hao, Pei; Feng, KaiYan; Cai, Yu-Dong; Li, Yixue

2011-01-01

Pyrrolidone carboxylic acid (PCA) is formed during a common post-translational modification (PTM) of extracellular and multi-pass membrane proteins. In this study, we developed a new predictor to predict the modification sites of PCA based on maximum relevance minimum redundancy (mRMR) and incremental feature selection (IFS). We incorporated 727 features that belonged to 7 kinds of protein properties to predict the modification sites, including sequence conservation, residual disorder, amino acid factor, secondary structure and solvent accessibility, gain/loss of amino acid during evolution, propensity of amino acid to be conserved at protein-protein interface and protein surface, and deviation of side chain carbon atom number. Among these 727 features, 244 features were selected by mRMR and IFS as the optimized features for the prediction, with which the prediction model achieved a maximum of MCC of 0.7812. Feature analysis showed that all feature types contributed to the modification process. Further site-specific feature analysis showed that the features derived from PCA's surrounding sites contributed more to the determination of PCA sites than other sites. The detailed feature analysis in this paper might provide important clues for understanding the mechanism of the PCA formation and guide relevant experimental validations. PMID:22174779

Studies on wound healing potential of polyherbal formulation using in vitro and in vivo assays.

PubMed

Talekar, Yogesh P; Apte, Kishori G; Paygude, Shubhangi V; Tondare, Prasad R; Parab, Pradeep B

The use of herbal plant extracts in wound healing is known through decades, but it is necessary to provide scientific data through reverse pharmacology. The aim of the present study is to find the mechanism behind the healing of wounds using in vitro and in vivo assays. The study was designed to determine proliferation and mobilization of fibroblast and keratinocytes at the site of injury, angiogenesis at the site of healing and reduction in oxidative stress while healing. In our earlier studies it was observed that herbal extract of Vitex negundo L. (VN), Emblica officinalis Gaertn (EO), and Tridax procumbens L. (TP) showed rapid regeneration of skin, wound contraction and collagen synthesis at the site of injury in excision wound model. In the present study the cell mobilization was monitored in the scratch assay on L929 fibroblastic cell line and HaCaT keratinocytes cell line under the influence of aqueous plant extracts and its formulation. This formulation was also assessed for its angiogenic potential using CAM assay. Study was carried out to probe synergistic effect of polyherbal formulation using excision model in rat. The formulation was found to contain high amount of flavonoids, tannins and phenols which facilitate wound healing. At 20 μg/ml concentration of formulation, significant increase in tertiary and quaternary vessels were observed due to angiogenic potential of formulation. Formulation at the concentration of 3 μg/ml and 5 μg/ml showed significant mobilization of keratinocytes and fibroblasts respectively at the site of injury. Polyherbal formulation showed rapid regeneration of skin and wound contraction. Biochemical parameters like hydroxyproline, hexosamine and collagen turnover was increased in test drug treated animals as compared to untreated, whereas antioxidants such as catalase and GSH were increased significantly and decreased amount of tissue MDA was observed. Polyherbal formulation prepared from the plant extracts accelerates wound healing process by proliferation and mobilization of fibroblast and keratinocytes, and angiogenesis at the site of injury. It also shows fast contraction of wound with its beneficial improvement in tissue biochemical and antioxidant parameters. Copyright © 2017 Transdisciplinary University, Bangalore and World Ayurveda Foundation. Published by Elsevier B.V. All rights reserved.

Expansion of deciduous tall shrubs but not evergreen dwarf shrubs inhibited by reindeer in Scandes mountain range.

PubMed

Vowles, Tage; Gunnarsson, Bengt; Molau, Ulf; Hickler, Thomas; Klemedtsson, Leif; Björk, Robert G

2017-11-01

One of the most palpable effects of warming in Arctic ecosystems is shrub expansion above the tree line. However, previous studies have found that reindeer can influence plant community responses to warming and inhibit shrubification of the tundra.We revisited grazed (ambient) and ungrazed study plots (exclosures), at the southern as well as the northern limits of the Swedish alpine region, to study long-term grazing effects and vegetation changes in response to increasing temperatures between 1995 and 2011, in two vegetation types (shrub heath and mountain birch forest).In the field layer at the shrub heath sites, evergreen dwarf shrubs had increased in cover from 26% to 49% but were unaffected by grazing. Deciduous dwarf and tall shrubs also showed significant, though smaller, increases over time. At the birch forest sites, the increase was similar for evergreen dwarf shrubs (20-48%) but deciduous tall shrubs did not show the same consistent increase over time as in the shrub heath.The cover and height of the shrub layer were significantly greater in exclosures at the shrub heath sites, but no significant treatment effects were found on species richness or diversity.July soil temperatures and growing season thawing degree days (TDD) were higher in exclosures at all but one site, and there was a significant negative correlation between mean shrub layer height and soil TDD at the shrub heath sites. Synthesis . This study shows that shrub expansion is occurring rapidly in the Scandes mountain range, both above and below the tree line. Tall, deciduous shrubs had benefitted significantly from grazing exclosure, both in terms of cover and height, which in turn lowered summer soil temperatures. However, the overriding vegetation shift across our sites was the striking increase in evergreen dwarf shrubs, which were not influenced by grazing. As the effects of an increase in evergreen dwarf shrubs and more recalcitrant plant litter may to some degree counteract some of the effects of an increase in deciduous tall shrubs, herbivore influence on shrub interactions is potentially of great importance for shaping arctic shrub expansion and its associated ecosystem effects.

On the substitution of Sr ions at Y sites in YB(suba2)Cu3O(sub7-d)

NASA Astrophysics Data System (ADS)

Siddiqi, S. A.; Sreedhar, K.; Drobac, D.; Infante, C.; Matacotta, F. C.; Ganguly, P.

1989-10-01

The effect of Sr substitution at the Ba sites in YBa2 Cu3 O sub 7-d has been studied; attempts to substitute Sr exclusively at Y sites have not been successful. We have been able to substitute Sr at Y sites only when the Ba ions are simultaneously substituted by Sr to give solid solutions of the type Y sub 1-x Sr sub x Ba sub 2-2x Sr sub 2x Cu3 O(sub 7-)x(sub /2-d). These examples show superconducting transitions higher than 78 K without significant deterioration in the magnitude of the ac susceptibility. The substitutions are best understood in terms of site constraints on the ions occupying the Y and Ba sites.

Identification of wild areas in southern lower Michigan. [terrain analysis from aerial photography, and satellite imagery

NASA Technical Reports Server (NTRS)

Habowski, S.; Cialek, C.

1978-01-01

An inventory methodology was developed to identify potential wild area sites. A list of site criteria were formulated and tested in six selected counties. Potential sites were initially identified from LANDSAT satellite imagery. A detailed study of the soil, vegetation and relief characteristics of each site based on both high-altitude aerial photographs and existing map data was conducted to eliminate unsuitable sites. Ground reconnaissance of the remaining wild areas was made to verify suitability and acquire information on wildlife and general aesthetics. Physical characteristics of the wild areas in each county are presented in tables. Maps show the potential sites to be set aside for natural preservation and regulation by the state under the Wilderness and Natural Areas Act of 1972.

Health assessment for Norman Poer Farm National Priorities List (NPL) Site, Hancock County, Indiana, Region 5. CERCLIS No. IND980684583. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The Norman Poer Farm National Priorities List site is situated in Hancock County, Indiana. Offgrade solvents and paint resin materials were stored on-site in 263 fifty-five gallon drums. The U.S. Environmental Protection Agency removed all the drums and the top six to eight inches of soil at the three drum storage areas in 1983. The Remedial Investigation (RI) conducted after the emergency removal did not show any contamination of the environment on-site or off-site. Based on the available information, the site is considered to be of no public health concern because of the absence of exposure to hazardous substances. Nomore » health study follow-up is indicated at this time.« less

Siting, design and operational controls for snow disposal sites.

PubMed

Wheaton, S R; Rice, W J

2003-01-01

The Municipality of Anchorage (MOA), at 61 degrees north latitude, ploughs and hauls snow from urban streets throughout the winter, incorporating grit and chloride applied to street surfaces for traffic safety. Hauled snow is stored at snow disposal facilities, where it melts at ambient spring temperatures. MOA studies performed from 1998 through 2001 show that disposal site melt processes can be manipulated, through site design and operation practices, to control chloride and turbidity in meltwater. An experimental passive "V-swale" pad configuration tested by MOA investigators reduced site meltwater turbidity by an order of magnitude (to about 50 NTU from the 500 NTU typical of more conventional planar pad geometry). The MOA has developed new siting, design and operational criteria for snow disposal facilities to conform to the tested V-swale pad configuration.

The moderating role of attachment anxiety on social network site use intensity and social capital.

PubMed

Liu, Haihua; Shi, Junqi; Liu, Yihao; Sheng, Zitong

2013-02-01

This study examined the moderating role of attachment anxiety on the relationship between intensity of social network site use and bridging, bonding, and maintained social capital. Data from 322 undergraduate Chinese students were collected. Hierarchical regression analyses showed positive relationships between online intensity of social network site use and the three types of social capital. Moreover, attachment anxiety moderated the effect of intensity of social network site use on social capital. Specifically, for students with lower attachment anxiety, the relationships between intensity of social network site use and bonding and bridging social capital were stronger than those with higher attachment anxiety. The result suggested that social network sites cannot improve highly anxiously attached individuals' social capital effectively; they may need more face-to-face communications.

Physical constraints determine the logic of bacterial promoter architectures

PubMed Central

Ezer, Daphne; Zabet, Nicolae Radu; Adryan, Boris

2014-01-01

Site-specific transcription factors (TFs) bind to their target sites on the DNA, where they regulate the rate at which genes are transcribed. Bacterial TFs undergo facilitated diffusion (a combination of 3D diffusion around and 1D random walk on the DNA) when searching for their target sites. Using computer simulations of this search process, we show that the organization of the binding sites, in conjunction with TF copy number and binding site affinity, plays an important role in determining not only the steady state of promoter occupancy, but also the order at which TFs bind. These effects can be captured by facilitated diffusion-based models, but not by standard thermodynamics. We show that the spacing of binding sites encodes complex logic, which can be derived from combinations of three basic building blocks: switches, barriers and clusters, whose response alone and in higher orders of organization we characterize in detail. Effective promoter organizations are commonly found in the E. coli genome and are highly conserved between strains. This will allow studies of gene regulation at a previously unprecedented level of detail, where our framework can create testable hypothesis of promoter logic. PMID:24476912

Long-term effect of tetracycline fibers on recurrent lesions in periodontal maintenance patients.

PubMed

Corsair, A

1994-01-01

Thirty-one patients with chronic adult periodontitis participated in this long-term private practice study. Sixty-one sites with moderate (4-6 mm, n = 21) or deep (> or = 7 mm, n = 40) periodontal pockets and bleeding on probing were treated with an antibiotic-releasing fiber, Actisite (Periodontal Therapeutic System) (tetracycline hydrochloride). Scaling/root planing (SRP) was performed on all teeth 3 weeks before start of the study, and on most teeth immediately before fiber insertion. Monolithic fibers loaded with 25% tetracycline hydrochloride were inserted in periodontal pockets, where they were retained for a mean of 6.7 days, at which point they were removed. Patients were evaluated at 1, 3, and 6 months after treatment; subgroups were also evaluated at normalized 12-month (10 patients, 20 sites) and 24-month (13 patients, 20 sites) time points. Sites showed a mean probing depth reduction of 2.5 mm at 6 months, and 2.2 mm at 24 months, with the deepest sites showing the greatest reduction. Bleeding on probing was 100% at baseline, 34% at 3 months, and 50% at 6 months. Attachment gains in 18 patients (25 sites) were 2.4 mm at 1 month, 3.0 mm at 3 months, and 2.5 mm at 6 months. Fibers were well tolerated; no adverse effects from treatment were noted. These results indicate that use of tetracycline fiber plus SRP clearly reduced the clinical signs of periodontal disease and maintained or improved attachment for up to 24 months in sites previously refractory to treatment.

Regulation of CYBB Gene Expression in Human Phagocytes by a Distant Upstream NF-κB Binding Site.

PubMed

Frazão, Josias B; Thain, Alison; Zhu, Zhiqing; Luengo, Marcos; Condino-Neto, Antonio; Newburger, Peter E

2015-09-01

The human CYBB gene encodes the gp91-phox component of the phagocyte oxidase enzyme complex, which is responsible for generating superoxide and other downstream reactive oxygen species essential to microbial killing. In the present study, we have identified by sequence analysis a putative NF-κB binding site in a DNase I hypersensitive site, termed HS-II, located in the distant 5' flanking region of the CYBB gene. Electrophoretic mobility assays showed binding of the sequence element by recombinant NF-κB protein p50 and by proteins in nuclear extract from the HL-60 myeloid leukemia cell line corresponding to p50 and to p50/p65 heterodimers. Chromatin immunoprecipitation demonstrated NF-κB binding to the site in intact HL-60 cells. Chromosome conformation capture (3C) assays demonstrated physical interaction between the NF-κB binding site and the CYBB promoter region. Inhibition of NF-κB activity by salicylate reduced CYBB expression in peripheral blood neutrophils and differentiated U937 monocytic leukemia cells. U937 cells transfected with a mutant inhibitor of κB "super-repressor" showed markedly diminished CYBB expression. Luciferase reporter analysis of the NF-κB site linked to the CYBB 5' flanking promoter region revealed enhanced expression, augmented by treatment with interferon-γ. These studies indicate a role for this distant, 15 kb upstream, binding site in NF-κB regulation of the CYBB gene, an essential component of phagocyte-mediated host defense. © 2015 Wiley Periodicals, Inc.

Impact of physicochemical parameters on phytoplankton compositions and abundances in Selameko Manmade Reservoir, Debre Tabor, South Gondar, Ethiopia

NASA Astrophysics Data System (ADS)

Wassie, Tilahun Adugna; Melese, Ayalew Wondie

2017-07-01

Impact of physicochemical parameters on 2 compositions and abundances in Selameko Reservoir, Debre Tabor, South Gondar from August 2009 to May 2010 was assessed. Water quality parameters, such as temperature, water transparency, water depth, dissolved oxygen, pH, total dissolved solids, phosphate, nitrate, and silicate were measured in situ from two sites (littoral and open water zone) of the reservoir. Phytoplankton compositions and abundances were analyzed in Tana fisheries and other aquatic organisms' research center. ANOVA result of the physicochemical parameters included chlorophyll-a showed the presence of significance difference among seasons and between sites ( P < 0.05). A total of seven families, 36 genera from three groups (Diatom, Blue green algae and Green algae) of phytoplankton were identified during the study period. From all groups, diatoms were the most abundant at both sites and Blue green algae were the least abundant. ANOVA of all phytoplankton showed highly significant difference among seasons and between sites ( P < 0.05). ANOVA of all phytoplankton showed highly significant difference among seasons and between sites ( P < 0.05). Based on the stepwise regression, a total number of phytoplanktons had positive correlation with some of the physicochemical parameters (R2 = 0.99, P < 0.001, N = 16). The study concluded that some of physicochemical parameters (NO3-N and PO4-P) indicated the presence of reservoir water pollution. This is supported by the presence of pollution-resistant phytoplankton species such as Melosira and Microcystis. The reservoir water was eutrophic (productive) throughout the year. To avoid such pollution, basin and reservoir management are recommended.

Intramural distribution of regulatory peptides in the sigmoid-recto-anal region of the human gut.

PubMed

Ferri, G L; Adrian, T E; Allen, J M; Soimero, L; Cancellieri, A; Yeats, J C; Blank, M; Polak, J M; Bloom, S R

1988-06-01

The distribution of regulatory peptides was studied in the separated mucosa, submucosa and muscularis externa taken at 10 sampling sites encompassing the whole human sigmoid colon (five sites), rectum (two sites), and anal canal (three sites). Consistently high concentrations of VIP were measured in the muscle layer at most sites (proximal sigmoid: 286 (16) pmol/g, upper rectum: 269 (17), a moderate decrease being found in the distal smooth sphincter (151 (30) pmol/g). Values are expressed as mean (SE). Conversely, substance P concentrations showed an obvious decline in the recto-anal muscle (mid sigmoid: 19 (2.0) pmol/g, distal rectum: 7.1 (1.3), upper anal canal: 1.6 (0.6)). Somatostatin was mainly present in the sigmoid mucosa and submucosa (37 (9.3) and 15 (3.5) pmol/g, respectively) and showed low, but consistent concentrations in the muscle (mid sigmoid: 2.2 (0.7) pmol/g, upper anal canal: 1.5 (0.8]. Starting in the distal sigmoid colon, a distinct peak of tissue NPY was revealed, which was most striking in the muscle (of mid sigmoid: 16 (3.9) pmol/g, upper rectum: 47 (7.8), anal sphincter: 58 (14)). Peptide YY was confined to the mucosa and showed an earlier peak (upper sigmoid: 709 (186) pmol/g, mid-distal sigmoid: 1965 (484)). A clear differential distribution of regulatory peptides was thus shown in the region studied. A possible role is suggested for NPY and VIP containing nerves in the effector control of the human internal anal sphincter.

Intramural distribution of regulatory peptides in the sigmoid-recto-anal region of the human gut.

PubMed Central

Ferri, G L; Adrian, T E; Allen, J M; Soimero, L; Cancellieri, A; Yeats, J C; Blank, M; Polak, J M; Bloom, S R

1988-01-01

The distribution of regulatory peptides was studied in the separated mucosa, submucosa and muscularis externa taken at 10 sampling sites encompassing the whole human sigmoid colon (five sites), rectum (two sites), and anal canal (three sites). Consistently high concentrations of VIP were measured in the muscle layer at most sites (proximal sigmoid: 286 (16) pmol/g, upper rectum: 269 (17), a moderate decrease being found in the distal smooth sphincter (151 (30) pmol/g). Values are expressed as mean (SE). Conversely, substance P concentrations showed an obvious decline in the recto-anal muscle (mid sigmoid: 19 (2.0) pmol/g, distal rectum: 7.1 (1.3), upper anal canal: 1.6 (0.6)). Somatostatin was mainly present in the sigmoid mucosa and submucosa (37 (9.3) and 15 (3.5) pmol/g, respectively) and showed low, but consistent concentrations in the muscle (mid sigmoid: 2.2 (0.7) pmol/g, upper anal canal: 1.5 (0.8]. Starting in the distal sigmoid colon, a distinct peak of tissue NPY was revealed, which was most striking in the muscle (of mid sigmoid: 16 (3.9) pmol/g, upper rectum: 47 (7.8), anal sphincter: 58 (14)). Peptide YY was confined to the mucosa and showed an earlier peak (upper sigmoid: 709 (186) pmol/g, mid-distal sigmoid: 1965 (484)). A clear differential distribution of regulatory peptides was thus shown in the region studied. A possible role is suggested for NPY and VIP containing nerves in the effector control of the human internal anal sphincter. PMID:2454876

Quantifying climate changes of the Common Era for Finland

NASA Astrophysics Data System (ADS)

Luoto, Tomi P.; Nevalainen, Liisa

2017-10-01

In this study, we aim to quantify summer air temperatures from sediment records from Southern, Central and Northern Finland over the past 2000 years. We use lake sediment archives to estimate paleotemperatures applying fossil Chironomidae assemblages and the transfer function approach. The used enhanced Chironomidae-based temperature calibration set was validated in a 70-year high-resolution sediment record against instrumentally measured temperatures. Since the inferred and observed temperatures showed close correlation, we deduced that the new calibration model is reliable for reconstructions beyond the monitoring records. The 700-year long temperature reconstructions from three sites at multi-decadal temporal resolution showed similar trends, although they had differences in timing of the cold Little Ice Age (LIA) and the initiation of recent warming. The 2000-year multi-centennial reconstructions from three different sites showed resemblance with each other having clear signals of the Medieval Climate Anomaly (MCA) and LIA, but with differences in their timing. The influence of external forcing on climate of the southern and central sites appeared to be complex at the decadal scale, but the North Atlantic Oscillation (NAO) was closely linked to the temperature development of the northern site. Solar activity appears to be synchronous with the temperature fluctuations at the multi-centennial scale in all the sites. The present study provides new insights into centennial and decadal variability in air temperature dynamics in Northern Europe and on the external forcing behind these trends. These results are particularly useful in comparing regional responses and lags of temperature trends between different parts of Scandinavia.

Drought-induced stomatal closure probably cannot explain divergent white spruce growth in the Brooks Range, Alaska, USA.

PubMed

Brownlee, Annalis H; Sullivan, Patrick F; Csank, Adam Z; Sveinbjörnsson, Bjartmar; Ellison, Sarah B Z

2016-01-01

Increment cores from the boreal forest have long been used to reconstruct past climates. However, in recent years, numerous studies have revealed a deterioration of the correlation between temperature and tree growth that is commonly referred to as divergence. In the Brooks Range of northern Alaska, USA, studies of white spruce (Picea glauca) revealed that trees in the west generally showed positive growth trends, while trees in the central and eastern Brooks Range showed mixed and negative trends during late 20th century warming. The growing season climate of the eastern Brooks Range is thought to be drier than the west. On this basis, divergent tree growth in the eastern Brooks Range has been attributed to drought stress. To investigate the hypothesis that drought-induced stomatal closure can explain divergence in the Brooks Range, we synthesized all of the Brooks Range white spruce data available in the International Tree Ring Data Bank (ITRDB) and collected increment cores from our primary sites in each of four watersheds along a west-to-east gradient near the Arctic treeline. For cores from our sites, we measured ring widths and calculated carbon isotope discrimination (δ13C), intrinsic water-use efficiency (iWUE), and needle intercellular CO2 concentration (C(i)) from δ13C in tree-ring alpha-cellulose. We hypothesized that trees exhibiting divergence would show a corresponding decline in δ13C, a decline in C(i), and a strong increase in iWUE. Consistent with the ITRDB data, trees at our western and central sites generally showed an increase in the strength of the temperature-growth correlation during late 20th century warming, while trees at our eastern site showed strong divergence. Divergent tree growth was not, however, associated with declining δ13C. Meanwhile, estimates of C(i) showed a strong increase at all of our study sites, indicating that more substrate was available for photosynthesis in the early 21st than in the early 20th century. Our results, which are corroborated by measurements of xylem sap flux density, needle gas exchange, and measurements of growth and δ13C along moisture gradients within each watershed, suggest that drought-induced stomatal closure is probably not the cause of 20th century divergence in the Brooks Range.

Site index curves for black, white, scarlet, and chestnut oaks in the Central States.

Treesearch

Willard H. Carmean

1971-01-01

Stem analyses showed polymorphic patterns of height growth for each species and for different levels of site quality. New site index curves are presented that show better height growth in later years than predicted by older harmonized site index curves.

High-resolution insight into the competitive adsorption of heavy metals on natural sediment by site energy distribution.

PubMed

Huang, Limin; Jin, Qiang; Tandon, Puja; Li, Aimin; Shan, Aidang; Du, Jiajie

2018-04-01

Investigating competitive adsorption on river/lake sediments is valuable for understanding the fate and transport of heavy metals. Most studies have studied the adsorption isotherms of competitive heavy metals, which mainly comparing the adsorption information on the same concentration. However, intrinsically, the concentration of each heavy metal on competitive adsorption sites is different, while the adsorption energy is identical. Thus, this paper introduced the site energy distribution theory to increase insight into the competitive adsorption of heavy metals (Cu, Cd and Zn). The site energy distributions of each metal with and without other coexisting heavy metals were obtained. It illustrated that site energy distributions provide much more information than adsorption isotherms through screening of the full energy range. The results showed the superior heavy metal in each site energy area and the influence of competitive metals on the site energy distribution of target heavy metal. Site energy distributions can further help in determining the competitive sites and ratios of coexisting metals. In particular, in the high-energy area, which has great environmental significance, the ratios of heavy metals in the competitive adsorption sites obtained for various competitive systems were as follows: slightly more than 3:1 (Cu-Cd), slightly less than 3:1 (Cu-Zn), slightly more than 1:1 (Cd-Zn), and nearly 7:2:2 (Cu-Cd-Zn). The results from this study are helpful to deeply understand competitive adsorption of heavy metals (Cu, Cd, Zn) on sediment. Therefore, this study was effective in presenting a general pattern for future reference in competitive adsorption studies on sediments. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electro-olfactogram and multiunit olfactory receptor responses to binary and trinary mixtures of amino acids in the channel catfish, Ictalurus punctatus

PubMed Central

1989-01-01

In vivo electrophysiological recordings from populations of olfactory receptor neurons in the channel catfish, Ictalurus punctatus, clearly showed that responses to binary and trinary mixtures of amino acids were predictable with knowledge obtained from previous cross-adaptation studies of the relative independence of the respective binding sites of the component stimuli. All component stimuli, from which equal aliquots were drawn to form the mixtures, were adjusted in concentration to provide for approximately equal response magnitudes. The magnitude of the response to a mixture whose component amino acids showed significant cross-reactivity was equivalent to the response to any single component used to form that mixture. A mixture whose component amino acids showed minimal cross-adaptation produced a significantly larger relative response than a mixture whose components exhibited considerable cross-reactivity. This larger response approached the sum of the responses to the individual component amino acids tested at the resulting concentrations in the mixture, even though olfactory receptor dose-response functions for amino acids in this species are characterized by extreme sensory compression (i.e., successive concentration increments produce progressively smaller physiological responses). Thus, the present study indicates that the response to sensory stimulation of olfactory receptor sites is more enhanced by the activation of different receptor site types than by stimulus interaction at a single site type. PMID:2703818

AmeriFlux US-KUT KUOM Turfgrass Field

DOE Data Explorer

McFadden, Joe [University of California, Santa Barbara

2016-01-01

This is the AmeriFlux version of the carbon flux data for the site US-KUT KUOM Turfgrass Field. Site Description - The site was a low-maintenace lawn consisting of cool-season turfgrasses, typical of residential lawns or urban parks in the study area. It was mowed to a height of 70 mm approximately once per week with clippings left to decompose on the surface, was not irrigated, and received one application of inorganic N fertilizer per year. The surrounding suburban residential neighborhood experienced rapid residential development in the 1950s; prior to that time, farms and nurseries were the predominant land-use types. Note that the land management of the field site changed (removal of the turfgrass lawn and planting of trees) AFTER the flux study was completed--this means that imagery after 2009 does not show the land conditions during the flux study.

Analysis of usability factors affecting purchase intention in online e-commerce sites

NASA Astrophysics Data System (ADS)

Perdana, R. A.; Suzianti, A.

2017-03-01

The growing number of internet users plays a significant role in the emergence of a variety of online e-commerce sites to meet the needs of Indonesians. However, there are still some problems faced by the users in using e-commerce sites. Therefore, a research related to user experience on their purchase intention to foster e-commerce sites is required. This study is conducted to find out the relationship between usability factors on e-commerce users’ purchase intention using a case study by using SEM to analyse the usability of the website. The result of this study shows that credibility, readability and telepresence are usability factors that directly affect purchase intention, while simplicity, consistency and interactivity are usability factors that indirectly affect purchase intention. Therefore, we can conclude that Indonesian consumers are on the Early Majority phase in adopting Company A.

Kinetics of Cation and Oxyanion Adsorption and Desorption on Ferrihydrite: Roles of Ferrihydrite Binding Sites and a Unified Model.

PubMed

Tian, Lei; Shi, Zhenqing; Lu, Yang; Dohnalkova, Alice C; Lin, Zhang; Dang, Zhi

2017-09-19

Quantitative understanding the kinetics of toxic ion reactions with various heterogeneous ferrihydrite binding sites is crucial for accurately predicting the dynamic behavior of contaminants in environment. In this study, kinetics of As(V), Cr(VI), Cu(II), and Pb(II) adsorption and desorption on ferrihydrite was studied using a stirred-flow method, which showed that metal adsorption/desorption kinetics was highly dependent on the reaction conditions and varied significantly among four metals. High resolution scanning transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy showed that all four metals were distributed within the ferrihydrite aggregates homogeneously after adsorption reactions. Based on the equilibrium model CD-MUSIC, we developed a novel unified kinetics model applicable for both cation and oxyanion adsorption and desorption on ferrihydrite, which is able to account for the heterogeneity of ferrihydrite binding sites, different binding properties of cations and oxyanions, and variations of solution chemistry. The model described the kinetic results well. We quantitatively elucidated how the equilibrium properties of the cation and oxyanion binding to various ferrihydrite sites and the formation of various surface complexes controlled the adsorption and desorption kinetics at different reaction conditions and time scales. Our study provided a unified modeling method for the kinetics of ion adsorption/desorption on ferrihydrite.

Biomonitoring of genotoxicity using micronuclei assay in native population of Astyanax jacuhiensis (Characiformes: Characidae) at sites under petrochemical influence.

PubMed

de Lemos, Clarice Torres; Iranço, Fábio de Almeida; de Oliveira, Nânci Cristina D'Avila; de Souza, Getúlio Dornelles; Fachel, Jandyra Maria Guimarães

2008-11-15

Bom Jardim brook is a small stream that flows through an area under the influence of a Petrochemical Complex, demanding control over its quality, so a genotoxic evaluation was performed. This study was conducted in situ, based on previous analysis on the same subject. These were performed both in vitro, with Salmonella typhimurium and human lymphocytes, and in vivo, using bioassays with fish exposed to water from the study area. The purpose of this research was to assess the quality of the aquatic environment and possible effects from petrochemical pollution to surrounding native populations. Micronuclei (MNE) and nuclear abnormalities (NA) frequencies in peripheral blood of Astyanax jacuhiensis, a native fish species collected from the study area, were used as biomarkers. Study period was from summer/99 to spring/2001, using samples obtained seasonally at two ponds upstream from the industrial area (BJN and BJPa) and two sites in Bom Jardim brook (BJ002 and BJ000), which are subject to Complex influence. MNE and NA frequencies found in individuals from BJ002 and BJ000 were similar, showing positive genotoxic responses related to control sites BJN and BJPa. No differential sensitivity could be verified for micronuclei induction between genders of A. jacuhiensis in the studied population. This study showed that sites subject to petrochemical influence were under higher genotoxic impact. Biomarkers adequacy to the case and the sensitivity of A. jacuhiensis for water monitoring could be also inferred.

Computational Optimization and Characterization of Molecularly Imprinted Polymers

NASA Astrophysics Data System (ADS)

Terracina, Jacob J.

Molecularly imprinted polymers (MIPs) are a class of materials containing sites capable of selectively binding to the imprinted target molecule. Computational chemistry techniques were used to study the effect of different fabrication parameters (the monomer-to-target ratios, pre-polymerization solvent, temperature, and pH) on the formation of the MIP binding sites. Imprinted binding sites were built in silico for the purposes of better characterizing the receptor - ligand interactions. Chiefly, the sites were characterized with respect to their selectivities and the heterogeneity between sites. First, a series of two-step molecular mechanics (MM) and quantum mechanics (QM) computational optimizations of monomer -- target systems was used to determine optimal monomer-to-target ratios for the MIPs. Imidazole- and xanthine-derived target molecules were studied. The investigation included both small-scale models (one-target) and larger scale models (five-targets). The optimal ratios differed between the small and larger scales. For the larger models containing multiple targets, binding-site surface area analysis was used to evaluate the heterogeneity of the sites. The more fully surrounded sites had greater binding energies. Molecular docking was then used to measure the selectivities of the QM-optimized binding sites by comparing the binding energies of the imprinted target to that of a structural analogue. Selectivity was also shown to improve as binding sites become more fully encased by the monomers. For internal sites, docking consistently showed selectivity favoring the molecules that had been imprinted via QM geometry optimizations. The computationally imprinted sites were shown to exhibit size-, shape-, and polarity-based selectivity. This represented a novel approach to investigate the selectivity and heterogeneity of imprinted polymer binding sites, by applying the rapid orientation screening of MM docking to the highly accurate QM-optimized geometries. Next, we sought to computationally construct and investigate binding sites for their enantioselectivity. Again, a two-step MM [special characters removed] QM optimization scheme was used to "computationally imprint" chiral molecules. Using docking techniques, the imprinted binding sites were shown to exhibit an enantioselective preference for the imprinted molecule over its enantiomer. Docking of structurally similar chiral molecules showed that the sites computationally imprinted with R- or S-tBOC-tyrosine were able to differentiate between R- and S-forms of other tyrosine derivatives. The cross-enantioselectivity did not hold for chiral molecules that did not share the tyrosine H-bonding functional group orientations. Further analysis of the individual monomer - target interactions within the binding site led us to conclude that H-bonding functional groups that are located immediately next to the target's chiral center, and therefore spatially fixed relative to the chiral center, will have a stronger contribution to the enantioselectivity of the site than those groups separated from the chiral center by two or more rotatable bonds. These models were the first computationally imprinted binding sites to exhibit this enantioselective preference for the imprinted target molecules. Finally, molecular dynamics (MD) was used to quantify H-bonding interactions between target molecules, monomers, and solvents representative of the pre-polymerization matrix. It was found that both target dimerization and solvent interference decrease the number of monomer - target H-bonds present. Systems were optimized via simulated annealing to create binding sites that were then subjected to molecular docking analysis. Docking showed that the presence of solvent had a detrimental effect on the sensitivity and selectivity of the sites, and that solvents with more H-bonding capabilities were more disruptive to the binding properties of the site. Dynamic simulations also showed that increasing the temperature of the solution can significantly decrease the number of H-bonds formed between the targets and monomers. It is believed that the monomer - target complexes formed within the pre-polymerization matrix are translated into the selective binding cavities formed during polymerization. Elucidating the nature of these interactions in silico improves our understanding of MIPs, ultimately allowing for more optimized sensing materials.

Effects of Warming on the Fate of Carbon Across a Hawaiian Soil Mineralogical Gradient

NASA Astrophysics Data System (ADS)

Neupane, A.

2016-12-01

Earth's surface temperature in tropical region have increased over the last century. However, relatively few studies have focused on the interacting effects of warming and soil mineralogy on the fate of carbon (C) in tropical soils. This research uses soils from three montane forest sites and two grasslands along soil age gradients on basaltic lava flows in Hawaii. The age gradient provides a range in soil mineralogies and binding site densities. We hypothesized that warming would promote microbial respiration and losses of added C more in younger soils with lower binding site density, whereas warming would have less of an impact on C losses in older soils with more reactive minerals. Soils were collected from 0-25 cm depths and incubated in the lab at 16 °C (ambient temperature), 21°C, and 26 °C. New C in the form of 13C-labeled glucose and glycine were added to replicate soils to track the fate of C with warming across sites (n = 3). Carbon dioxide (CO2) fluxes was measured every 15 to 30 days for 8 months to assess changes in heterotrophic respiration, and 13C uptake in microbial biomass was measured after 4 days and 8 months. Among the forest sites, the youngest soils (Thurston, 300 years old), had the overall lowest respiration, an intermediate aged soil (Laupahoehoe, 20,000 years old) had the highest respiration, and there was intermediate respiration from the oldest soil (Kohala, 150,000 yrs). Both the grassland sites had lower respiration compared to the forest. Soils from all sites showed increase in respiration rate at warmer temperature. Contrary to expectations, Kohala soil showed largest increase in respiration upon warming while Thurston showed the smallest increase for the forest sites. The C substrates altered respiration differently over time. Preliminary microbial 13C data show significant uptake and retention of added substrates in microbial biomass during the first 4 days of the incubation, with significantly greater retention of added substrate in microbial biomass at 16 °C versus 21 oC. These results show that warming not only increases heterotrophic respiration of C, but also decreases microbial retention of simple C substrates. These results, together with analyses across the soil mineralogical gradient, will improve our understanding of how warming may affect C storage across tropical sites.

Temperature Dependence of Magnetically Active Charge Excitations in Magnetite across the Verwey Transition

NASA Astrophysics Data System (ADS)

Taguchi, M.; Chainani, A.; Ueda, S.; Matsunami, M.; Ishida, Y.; Eguchi, R.; Tsuda, S.; Takata, Y.; Yabashi, M.; Tamasaku, K.; Nishino, Y.; Ishikawa, T.; Daimon, H.; Todo, S.; Tanaka, H.; Oura, M.; Senba, Y.; Ohashi, H.; Shin, S.

2015-12-01

We study the electronic structure of bulk single crystals and epitaxial films of Fe3 O4 . Fe 2 p core level spectra show clear differences between hard x-ray (HAX) and soft x-ray photoemission spectroscopy (PES). The bulk-sensitive spectra exhibit temperature (T ) dependence across the Verwey transition, which is missing in the surface-sensitive spectra. By using an extended impurity Anderson full-multiplet model—and in contrast to an earlier peak assignment—we show that the two distinct Fe species (A and B site) and the charge modulation at the B site are responsible for the newly found double peaks in the main peak above TV and its T -dependent evolution. The Fe 2 p HAXPES spectra show a clear magnetic circular dichroism (MCD) in the metallic phase of magnetized 100-nm-thick films. The model calculations also reproduce the MCD and identify the contributions from magnetically distinct A and B sites. Valence band HAXPES shows a finite density of states at EF for the polaronic half metal with a remnant order above TV and a clear gap formation below TV. The results indicate that the Verwey transition is driven by changes in the strongly correlated and magnetically active B -site electronic states, consistent with resistivity and optical spectra.

Trends in 1970-2010 southern California surface maximum temperatures: extremes and heat waves

NASA Astrophysics Data System (ADS)

Ghebreegziabher, Amanuel T.

Daily maximum temperatures from 1970-2010 were obtained from the National Climatic Data Center (NCDC) for 28 South Coast Air Basin (SoCAB) Cooperative Network (COOP) sites. Analyses were carried out on the entire data set, as well as on the 1970-1974 and 2006-2010 sub-periods, including construction of spatial distributions and time-series trends of both summer-average and annual-maximum values and of the frequency of two and four consecutive "daytime" heat wave events. Spatial patterns of average and extreme values showed three areas consistent with climatological SoCAB flow patterns: cold coastal, warm inland low-elevation, and cool further-inland mountain top. Difference (2006-2010 minus 1970-1974) distributions of both average and extreme-value trends were consistent with the shorter period (1970-2005) study of previous study, as they showed the expected inland regional warming and a "reverse-reaction" cooling in low elevation coastal and inland areas open to increasing sea breeze flows. Annual-extreme trends generally showed cooling at sites below 600 m and warming at higher elevations. As the warming trends of the extremes were larger than those of the averages, regional warming thus impacts extremes more than averages. Spatial distributions of hot-day frequencies showed expected maximum at inland low-elevation sites. Regional warming again thus induced increases at both elevated-coastal areas, but low-elevation areas showed reverse-reaction decreases.

Effectiveness of a bundled intervention of decolonization and prophylaxis to decrease Gram positive surgical site infections after cardiac or orthopedic surgery: systematic review and meta-analysis.

PubMed

Schweizer, Marin; Perencevich, Eli; McDanel, Jennifer; Carson, Jennifer; Formanek, Michelle; Hafner, Joanne; Braun, Barbara; Herwaldt, Loreen

2013-06-13

To evaluate studies assessing the effectiveness of a bundle of nasal decolonization and glycopeptide prophylaxis for preventing surgical site infections caused by Gram positive bacteria among patients undergoing cardiac operations or total joint replacement procedures. Systematic review and meta-analysis. PubMed (1995 to 2011), the Cochrane database of systematic reviews, CINAHL, Embase, and clinicaltrials.gov were searched to identify relevant studies. Pertinent journals and conference abstracts were hand searched. Study authors were contacted if more data were needed. Randomized controlled trials, quasi-experimental studies, and cohort studies that assessed nasal decolonization or glycopeptide prophylaxis, or both, for preventing Gram positive surgical site infections compared with standard care. Patients undergoing cardiac operations or total joint replacement procedures. DATA EXTRACTION AND STUDY APPRAISAL: Two authors independently extracted data from each paper and a random effects model was used to obtain summary estimates. Risk of bias was assessed using the Downs and Black or the Cochrane scales. Heterogeneity was assessed using the Cochran Q and I(2) statistics. 39 studies were included. Pooled effects of 17 studies showed that nasal decolonization had a significantly protective effect against surgical site infections associated with Staphylococcus aureus (pooled relative risk 0.39, 95% confidence interval 0.31 to 0.50) when all patients underwent decolonization (0.40, 0.29 to 0.55) and when only S aureus carriers underwent decolonization (0.36, 0.22 to 0.57). Pooled effects of 15 prophylaxis studies showed that glycopeptide prophylaxis was significantly protective against surgical site infections related to methicillin (meticillin) resistant S aureus (MRSA) compared with prophylaxis using β lactam antibiotics (0.40, 0.20 to 0.80), and a non-significant risk factor for methicillin susceptible S aureus infections (1.47, 0.91 to 2.38). Seven studies assessed a bundle including decolonization and glycopeptide prophylaxis for only patients colonized with MRSA and found a significantly protective effect against surgical site infections with Gram positive bacteria (0.41, 0.30 to 0.56). Surgical programs that implement a bundled intervention including both nasal decolonization and glycopeptide prophylaxis for MRSA carriers may decrease rates of surgical site infections caused by S aureus or other Gram positive bacteria.

Biological assessment of streams in the Indianapolis Metropolitan Area, Indiana, 1999-2001

USGS Publications Warehouse

Voelker, David C.

2004-01-01

During 1999?2001, benthic invertebrates and fish were sampled to describe biological communities in the White River and selected tributaries in the Indianapolis Metropolitan Area in Indiana. Twelve sites (six on the White River and six on tributaries) were sampled biannually for benthic invertebrates and annually for fish. The information complements water-chemistry data collected by the Indianapolis Department of Public Works in the study area. Evaluation of the habitat for sites in the study area was done, using a Qualitative Habitat Evaluation Index (QHEI) developed by the Ohio Environmental Protection Agency. The QHEI scores basin and habitat characteristics for each site, with a maximum possible score of 100. Higher scores indicate better habitat conditions for biotic communities. The QHEI scores for sites on the White River ranged from 55 at the Harding site to 71 at the Waverly site; scores on the tributaries ranged from 45 on Pogues Run to 82 on Williams Creek. A total of 151 taxa were identified from the benthic-invertebrate samples. The Ephemeroptera, Plecoptera, and Trichoptera (EPT) Index scores for sites on the White River ranged from 0 at the Harding site to 15 at the Nora site. The Nora site, which is upstream from Indianapolis, generally scored the highest of all White River sites. Sites in the immediate vicinity of Indianapolis scored the lowest and indicate a negative effect on benthic-invertebrate communities in that reach. EPT Index scores increased in the farthest downstream reaches, which indicate that water-quality conditions had improved in comparison to sites in Indianapolis. For the tributary sites, EPT Index values ranged from 0 at Pogues Run to 16 at Buck Creek. Tributary sites on Fall Creek, Pleasant Run, and Pogues Run consistently scored 7 or lower; sites on Buck Creek, Eagle Creek, and Williams Creek scored 7 or higher. Hilsenhoff Biotic Index (HBI) scores ranged from 4.9 (good) to 9.6 (very poor) for the White River sites and from 5.2 (good) to 8.0 (poor) for the tributary sites. The lowest scores among the White River sites were at the Nora site, indicating the best water-quality conditions were where the White River enters Marion County. The highest HBI scores were at the Morris and Harding sites, indicating the least-favorable water-quality conditions of all the White River sites. Of the tributary sites, HBI scores for Buck, Eagle, and Williams Creeks indicate fair water-quality conditions; HBI scores for Pleasant Run and Pogues Run were the highest, indicating relatively poor water-quality conditions. On the White River, the highest Invertebrate Community Index (ICI) scores, which indicate the best benthic-invertebrate conditions, were at the Nora site. Conditions were fair to poor in the downtown Indianapolis area; ICI scores indicate slight improvement in the downstream reaches of the study area. Of the tributary sites, Buck Creek was the only site with ICI scores indicating exceptional water quality. Williams Creek ICI scores indicate good water quality; the remaining tributary-site scores reflect fair conditions. A total of 74 species and 3 hybrids of fish were identified during the study period. The Cyprinidae (carps and minnows) was the largest group of fish identified and consisted of more than half of all fish collected. The most numerous species was the central stoneroller (Campostoma anomalum), which accounted for almost 25 percent of the fish identified. Two nonnative species, the koi carp (Cyprinus carpio) and the western mosquitofish (Gambusia affinis), and one species classified as an Indiana species of special concern, the northern studfish (Fundulus catenatus), also were collected during the study. Indiana Index of Biotic Integrity (IBI) and Ohio Index of Biotic Integrity scores were calculated to show the condition of the fish communities at each site. Results of the Indiana IBI calculations showed no apparent differences in scores among the Wh

A Long-Term Macroecological Analysis of the Recovery of a Waterbird Metacommunity after Site Protection

PubMed Central

Pagel, Janina; Martínez-Abraín, Alejandro; Gómez, Juan Antonio; Jiménez, Juan; Oro, Daniel

2014-01-01

We used the so called “land-bridge island” or “nested-subsets” theory to test the resilience of a highly fragmented and perturbated waterbird metacommunity, after legal protection of 18 wetlands in the western Mediterranean. Sites were monitored during 28 years and two seasons per year. The metacommunity was composed by 44 species during breeding and 67 species during wintering, including shorebirds, ducks, herons, gulls and divers (Podicipedidae). We identified a strong nested pattern. Consistent with the fact that the study system was to a large extent a spatial biogeographical continuous for thousands of years, fragmented only during the last centuries due to human activities. Non-random selective extinction was the most likely historical process creating the nested pattern, operated by the differential carrying capacity (surface-area) of the remaining sites. We also found a positive temporal trend in nestedness and a decreasing trend in species turnover among sites (β-diversity), indicating that sites are increasingly more alike to each other (i.e. increased biotic homogenization). This decreasing trend in β-diversity was explained by an increasing trend in local (α) diversity by range expansion of half the study species. Regional (γ) diversity also increased over time, indicating that colonization from outside the study system also occurred. Overall our results suggest that the study metacommunity is recovering from historical anthropogenic perturbations, showing a high long-term resilience, as expected for highly vagile waterbirds. However, not all waterbird groups contributed equally to the recovery, with most breeding shorebird species and most wintering duck species showing no geographical expansion. PMID:25133798

Does Jatropha curcas L. show resistance to drought in the Sahelian zone of West Africa? A case study from Burkina Faso

NASA Astrophysics Data System (ADS)

Bayen, P.; Sop, T. K.; Lykke, A. M.; Thiombiano, A.

2015-05-01

Land degradation is an environmental problem which weakens agro-sylvo-pastoral productivity in sub-Saharan Africa. The most common manifestation of land degradation is the appearance of denuded land. We carried out an experiment to test the effect of three soil and water conservation techniques on survival and growth of Jatropha curcas seedlings transplanted onto two completely denuded lands in the Sahelian and Sudanian zones of Burkina Faso. We implemented an experimental design with three replicates per restoration technique. A total of 174 seedlings were planted in each study site. The results showed that the soil water content varied according to the restoration technique used (df = 2; F = 53.21; p < 0.00) as well as according to study site (df = 1; F = 74.48; p < 0.00). Soil water content was significantly lower in the Sahel than in the Sudanian zone. Seedling survival rate varied significantly according to technique used (df = 2; F = 8.91; p = 0.000) and study site (df = 1; F = 9.74; p = 0.003). Survival rate, diameter and seedling height were highest at the Sudanian site. At the Sahelian site, all seedlings died 2 years after establishment. These results suggest that J. curcas is unsuited to denuded land in the Sahelian zone. Most of the plants died in the Sahel between April and May, which is the peak of the dry season; this may be an indication that J. curcas may not be as drought-resistant as suggested by the prolific literature which has reported on diverse claims surrounding this plant.

Does Jatropha curcas L. show resistance to drought in the Sahelian zone of West Africa? A case study from Burkina Faso

NASA Astrophysics Data System (ADS)

Bayen, P.; Sop, T. K.; Lykke, A. M.; Thiombiano, A.

2015-02-01

Land degradation is an environmental problem which weakens agro-silvo-pastoral productivity in Sub-Saharan Africa. The most common manifestation of land degradation is the appearance of denuded land. We carried out an experiment to test the effect of three soil and water conservation techniques on survival and growth of Jatropha curcas seedlings transplanted onto two completely denuded lands in the Sahelian and Sudanian zones of Burkina Faso. We implemented an experimental design with three replicates per restoration technique. A total of 174 seedlings were planted in each study site. The results showed that soil water content varied according to the restoration technique used (df = 2; F = 53.21; p < 0.00) as well as according to study site (df = 1; F = 74.48; p < 0.00). Soil water content was significantly lower in the Sahel than in the Sudanian zone. Seedling survival rate varied significantly according to technique used (df = 2; F = 8.91; p = 0.000) and study site (df = 1; F = 9.74; p = 0.003). Survival rate, diameter and seedling height were highest at the Sudanian site. At the Sahelian site, all seedlings died two years after establishment. These results suggest that Jatropha curcas is unsuited to denuded land in the Sahelian zone. Most of the plants died in the Sahel between April and May, which is the peak of the dry season; this may be an indication that Jatropha may not be as drought-resistant as suggested by the prolific literature which has reported on diverse claims surrounding this plant.

A first-principles comparative study of lithium, sodium, and magnesium storage in pure and gallium-doped germanium: Competition between interstitial and substitutional sites

NASA Astrophysics Data System (ADS)

Legrain, Fleur; Manzhos, Sergei

2017-01-01

Thermodynamics and kinetics of Li, Na, and Mg storage in Ge are studied ab initio. The most stable configurations can consist of tetrahedral, substitutional, or a combination of the two types of sites. In the dilute limit, Li and Na prefer interstitial, while Mg prefers substitutional sites. At higher concentrations of Li, Na, and Mg, there is a combination of interstitial and substitutional sites. This is an important finding, as most previous ab initio studies of alloying type electrode materials ignored substitutional sites. Insertion energies computed at dilute concentration (x = 1/64) show that Na and Mg insertion are not thermodynamically favored in Ge vs. the formation of bulk Na and Mg, as opposed to Li insertion which is favored. We investigate the effect of p-doping of Ge (with Ga) on the thermodynamics and find that it considerably lowers the defect formation energies associated with the insertion of Li/Na/Mg at tetrahedral sites. On the other hand, the energetics associated with Li/Na/Mg insertion at substitutional sites are not significantly affected. In addition, we compute the migration energy barriers for Li/Na/Mg diffusion between two tetrahedral sites (0.38/0.79/0.66 eV), between two substitutional sites (0.77/0.93/1.83 eV), and between two sites of different types (2.15/1.75/0.85 eV).

A first-principles comparative study of lithium, sodium, and magnesium storage in pure and gallium-doped germanium: Competition between interstitial and substitutional sites.

PubMed

Legrain, Fleur; Manzhos, Sergei

2017-01-21

Thermodynamics and kinetics of Li, Na, and Mg storage in Ge are studied ab initio. The most stable configurations can consist of tetrahedral, substitutional, or a combination of the two types of sites. In the dilute limit, Li and Na prefer interstitial, while Mg prefers substitutional sites. At higher concentrations of Li, Na, and Mg, there is a combination of interstitial and substitutional sites. This is an important finding, as most previous ab initio studies of alloying type electrode materials ignored substitutional sites. Insertion energies computed at dilute concentration (x = 1/64) show that Na and Mg insertion are not thermodynamically favored in Ge vs. the formation of bulk Na and Mg, as opposed to Li insertion which is favored. We investigate the effect of p-doping of Ge (with Ga) on the thermodynamics and find that it considerably lowers the defect formation energies associated with the insertion of Li/Na/Mg at tetrahedral sites. On the other hand, the energetics associated with Li/Na/Mg insertion at substitutional sites are not significantly affected. In addition, we compute the migration energy barriers for Li/Na/Mg diffusion between two tetrahedral sites (0.38/0.79/0.66 eV), between two substitutional sites (0.77/0.93/1.83 eV), and between two sites of different types (2.15/1.75/0.85 eV).

Intradiencephalon injection of histamine inhibited the recovery of locomotor function of spinal cord injured zebrafish.

PubMed

Huang, Shu-Bing; Zhao, Hou-De; Wang, Lin-Fang; Sun, Meng-Fei; Zhu, Ying-Li; Wu, Yi-Bo; Xu, Yi-Da; Peng, Shi-Xiao; Cui, Chun; Shen, Yan-Qin

2017-07-29

Human spinal cord injury (SCI) usually causes irreversible disability beneath the injured site due to poor neural regeneration. On the contrary, zebrafish show significant regenerative ability after SCI, thus is usually worked as an animal model for studying neuroregeneration. Most of the previous SCI studies focused on the local site of SCI, the supraspinal-derived signals were rarely mentioned. Here we showed that intradiencephalon injection of histamine (HA) inhibited the locomotor recovery in adult zebrafish post-SCI. Immunofluorescence results showed that intradiencephalon HA administration increased the activated microglia 3 days post injury (dpi), promoted the proliferation of radial glial cells at 7 dpi and affected the morphology of radial glial cells at 11 dpi. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) results showed that intradiencephalon HA administration also reduced the expression of neurotrophic factors including brain-derived neurotrophic factor (BDNF) and insulin-like growth factor1 (IGF-1) at the lesion site, however, had no effect on the expression of pro-inflammatory factors such as TNF-alpha and IL-1 beta. Hence, our data suggested that exogenous intradiencephalon HA retarded locomotor recovery in spinal cord injured zebrafish via modulating the repair microenvironment. Copyright © 2017 Elsevier Inc. All rights reserved.

Assessment of heavy metals contamination in soil profiles of roadside Suaeda salsa wetlands in a Chinese delta

NASA Astrophysics Data System (ADS)

Wen, Xiaojun; Wang, Qinggai; Zhang, Guangliang; Bai, Junhong; Wang, Wei; Zhang, Shuai

2017-02-01

Five sampling sites (Sites A, B, C, D and E) were selected along a 250 m sampling zone covered by Suaeda salsa, which is perpendicular to a road, in the Yellow River Delta of China. Soil samples were collected to a depth of 40cm in these five sampling sites to investigate the profile distributions and toxic risks of heavy metals. Concentrations of heavy metals (As, Cd, Cr, Cu, Ni, Pb and Zn) were determined using inductively coupled plasma atomic absorption spectrometry (ICP-AAS). The results showed that in each sampling site, Cd, Cu, Pb and Zn have approximately constant concentrations along soil profiles and did not show high contamination compared with the values of probable effect levels (PELs). All soils exhibited As and Ni contamination at all sampling sites compared with other heavy metals. The index of geo-accumulation (Igeo) values for As in the 20-30 cm soil layer at Site B was grouped into Class Ⅳ(2 < Igeo ≤ 3), indicating that the soil was moderately to strongly contaminated. Forty percent of Igeo values of Cd for all soil samples were grouped into Class Ⅳ(2 < Igeo ≤ 3) and 75% samples of Site C showed moderately to strongly contaminated level. The Enrichment factor (EF) values of As at Sites B, C, D and E reached significant enrichment level and EF values of Cd at five sampling sites all reached significant enrichment level. The sum of toxic units (∑TUs) values for surface soils of Sites B and C beyond 4 indicated that Sites B and C have severer toxicity compared with other three sampling sites. As and Ni should be paid more attention to avoid potential ecotoxicity due to their high contribution ratios to the ∑TUs in Suaeda salsa wetlands. Correlation analysis (CA) and principal components analysis (PCA) revealed that Cr, Cu, Ni, Pb and Zn might derive from the common sources, Cd might originate from another, while As might have more complex sources in this study area.

Roadside soils show low plant available zinc and copper concentrations.

PubMed

Morse, Natalie; Walter, M Todd; Osmond, Deanna; Hunt, William

2016-02-01

Vehicle combustion and component wear are a major source of metal contamination in the environment, which could be especially concerning where road ditches are actively farmed. The objective of this study was to assess how site variables, namely age, traffic (vehicles day(-1)), and percent carbon (%C) affect metal accumulation in roadside soils. A soil chronosequence was established with sites ranging from 3 to 37 years old and bioavailable, or mobile, concentrations of Zinc (Zn) and Copper (Cu) were measured along major highways in North Carolina using a Mehlich III extraction. Mobile Zn and Cu concentrations were low overall, and when results were scaled via literature values to "total metal", the results were still generally lower than previous roadside studies. This could indicate farming on lands near roads would pose a low plant toxicity risk. Zinc and Cu were not correlated with annual average traffic count, but were positively correlated with lifetime traffic load (the product of site age and traffic count). This study shows an often overlooked variable, site age, should be included when considering roadside pollution accumulation. Zinc and Cu were more strongly associated with %C, than traffic load. Because vehicle combustion is also a carbon source, it is not obvious whether the metals and carbon are simply co-accumulating or whether the soil carbon in roadside soils may facilitate previously overlooked roles in sequestering metals on-site. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluating Changes in Distributions of Summer Stream Temperature following Forest Harvest

NASA Astrophysics Data System (ADS)

Johnson, S. L.; Reiter, M.; Jones, J.

2016-12-01

Stream temperature heat budgets are influenced by numerous processes; changes in incoming radiation have been shown to be a major driver of increased stream temperatures. Maximum daily temperature is a commonly used metric for evaluating stream temperature responses to land use. However, single metrics are not able to fully represent the magnitude and duration of temperatures experienced by instream biota. Analyses that make use of all the data: a) more accurately characterize shifts in summer stream temperature regimes, b) quantify potential exposure to critical and non-critical temperatures, and c) help researchers and managers to better understand stream temperature responses to manipulation of streamside and watershed vegetation. Here we examine the distributions of summer stream temperatures before and after forest harvest in the Trask River Watershed Study, in northwestern Oregon. We studied 15 small streams for 10 years; half of the sites had their catchments clearcut harvested in 2012. Four sites had no buffers, with some leave trees, and three sites had 25 ft buffers on both sides. Temperatures were measured during at 30min intervals. Even though these streams are generally cold, we observed high spatial and temporal variation among sites and years, with some sites having normally distributed temperatures, while others showed skewed distributions and long tails. Forest cover, aspect or elevation were not good predictors of temperature distributions pre-harvest. Preliminary analyses using travel time of the stream water suggest that sites with hyporheic flows had narrower distributions of temperatures. After harvest, sites without buffers showed the greatest shift in distributions of temperatures and widest temperature ranges, while sites with narrow buffers showed little change. We are exploring the implications of shifts in temperature distributions before and after harvest against the known thermal tolerances for the dominant resident species (Ascaphus truei; tailed frog tadpoles) in these headwater streams. Rarely in forested mountain landscapes do stream temperatures exceed lethal thresholds for cold water biota; with these analyses, we are quantifying chronic exposure, which could subsequently result in shifts in phenology or community structure.

[Study on artificial neural network combined with multispectral remote sensing imagery for forest site evaluation].

PubMed

Gong, Yin-Xi; He, Cheng; Yan, Fei; Feng, Zhong-Ke; Cao, Meng-Lei; Gao, Yuan; Miao, Jie; Zhao, Jin-Long

2013-10-01

Multispectral remote sensing data containing rich site information are not fully used by the classic site quality evaluation system, as it merely adopts artificial ground survey data. In order to establish a more effective site quality evaluation system, a neural network model which combined remote sensing spectra factors with site factors and site index relations was established and used to study the sublot site quality evaluation in the Wangyedian Forest Farm in Inner Mongolia Province, Chifeng City. Based on the improved back propagation artificial neural network (BPANN), this model combined multispectral remote sensing data with sublot survey data, and took larch as example, Through training data set sensitivity analysis weak or irrelevant factor was excluded, the size of neural network was simplified, and the efficiency of network training was improved. This optimal site index prediction model had an accuracy up to 95.36%, which was 9.83% higher than that of the neural network model based on classic sublot survey data, and this shows that using multi-spectral remote sensing and small class survey data to determine the status of larch index prediction model has the highest predictive accuracy. The results fully indicate the effectiveness and superiority of this method.

Population dose commitments due to radioactive releases from nuclear power plant sites in 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commericial power reactors operating during 1985. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 61 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km aroundmore » each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 73 person-rem to a low of 0.011 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 3 person-rem. The total population dose for all sites was estimated at 200 person-rem for the 110 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 5 /times/ 10/sup /minus/6/ mrem to a high of 0.02 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites.« less

Population dose commitments due to radioactive releases from nuclear power plant sites in 1984

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1984. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 56 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km aroundmore » each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 110 person-rem to a low of 0.002 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 5 person-rem. The total population dose for all sites was estimated at 280 person-rem for the 100 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 6 x 10/sup -6/ mrem to a high of 0.04 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites.« less

Population dose commitments due to radioactive releases from nuclear power plant sites in 1986

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1986. Fifty-year dose commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 66 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 kmmore » around each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 31 person-rem to a low of 0.0007 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 1.7 person-rem. The total population dose for all sites was estimated at 110 person-rem for the 140 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 2 {times} 10{sup -6} mrem to a high of 0.02 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites. 12 refs.« less

Site-to-site interdomain communication may mediate different loss-of-function mechanisms in a cancer-associated NQO1 polymorphism

NASA Astrophysics Data System (ADS)

Medina-Carmona, Encarnación; Neira, Jose L.; Salido, Eduardo; Fuchs, Julian E.; Palomino-Morales, Rogelio; Timson, David J.; Pey, Angel L.

2017-03-01

Disease associated genetic variations often cause intracellular enzyme inactivation, dysregulation and instability. However, allosteric communication of mutational effects to distant functional sites leading to loss-of-function remains poorly understood. We characterize here interdomain site-to-site communication by which a common cancer-associated single nucleotide polymorphism (c.C609T/p.P187S) reduces the activity and stability in vivo of NAD(P)H:quinone oxidoreductase 1 (NQO1). NQO1 is a FAD-dependent, two-domain multifunctional stress protein acting as a Phase II enzyme, activating cancer pro-drugs and stabilizing p53 and p73α oncosuppressors. We show that p.P187S causes structural and dynamic changes communicated to functional sites far from the mutated site, affecting the FAD binding site located at the N-terminal domain (NTD) and accelerating proteasomal degradation through dynamic effects on the C-terminal domain (CTD). Structural protein:protein interaction studies reveal that the cancer-associated polymorphism does not abolish the interaction with p73α, indicating that oncosuppressor destabilization largely mirrors the low intracellular stability of p.P187S. In conclusion, we show how a single disease associated amino acid change may allosterically perturb several functional sites in an oligomeric and multidomain protein. These results have important implications for the understanding of loss-of-function genetic diseases and the identification of novel structural hot spots as targets for pharmacological intervention.

Different Requirements for Proteolytic Processing of Bone Morphogenetic Protein 5/6/7/8 Ligands in Drosophila melanogaster*

PubMed Central

Fritsch, Cornelia; Sawala, Annick; Harris, Robin; Maartens, Aidan; Sutcliffe, Catherine; Ashe, Hilary L.; Ray, Robert P.

2012-01-01

Bone morphogenetic proteins (BMPs) are synthesized as proproteins that undergo proteolytic processing by furin/subtilisin proprotein convertases to release the active ligand. Here we study processing of BMP5/6/7/8 proteins, including the Drosophila orthologs Glass Bottom Boat (Gbb) and Screw (Scw) and human BMP7. Gbb and Scw have three functional furin/subtilisin proprotein convertase cleavage sites; two between the prodomain and ligand domain, which we call the Main and Shadow sites, and one within the prodomain, which we call the Pro site. In Gbb each site can be cleaved independently, although efficient cleavage at the Shadow site requires cleavage at the Main site, and remarkably, none of the sites is essential for Gbb function. Rather, Gbb must be processed at either the Pro or Main site to produce a functional ligand. Like Gbb, the Pro and Main sites in Scw can be cleaved independently, but cleavage at the Shadow site is dependent on cleavage at the Main site. However, both Pro and Main sites are essential for Scw function. Thus, Gbb and Scw have different processing requirements. The BMP7 ligand rescues gbb mutants in Drosophila, but full-length BMP7 cannot, showing that functional differences in the prodomain limit the BMP7 activity in flies. Furthermore, unlike Gbb, cleavage-resistant BMP7, although non-functional in rescue assays, activates the downstream signaling cascade and thus retains some functionality. Our data show that cleavage requirements evolve rapidly, supporting the notion that changes in post-translational processing are used to create functional diversity between BMPs within and between species. PMID:22199351

Clinical accuracy of non-contact infrared thermometer from umbilical region in children: A new side.

PubMed

Apa, Hurşit; Gözmen, Salih; Keskin-Gözmen, Şükran; Aslan, Fatma; Bayram, Nuri; Devrim, İlker

2016-01-01

Measurement from axillary site with digital thermometer has been accepted as the most accurate method. But this method is time consuming. Tympanic and forehead measurements are often used but don't always seem to be more appropriate. Another site, umbilical region, could be an alternative site. This study aims to compare the measurements with axillary digital thermometer and non-contact infrared thermometers at sites from umbilicus and forehead to determine whether umbilical site could be used accurately in children. For each method, 2,048 measurements in total were performed. Using axillary method as gold standard, with a cut-off temperature of 38oC, the sensitivities and specificities, positive and negative predictive values of umbilical and forehead temperatures and area under the ROC curve were determined in non obese children. There was a significant positive correlation between axillary and umbilical temperatures with a correlation coefficient of 0.78. The average difference between the mean of both axillary and umbilical temperatures was -0.47 ± 0.65°C. The Bland-Altman plot showed good accuracy with only 2.5 % of the readings falling outside the 95% level of confidence. Umbilical measurements showed sensitivity of 71.7% and specificity of 95.8%. The area under the ROC curve was 0.93. The easy application may lead noncontact measurements from umbilicus site to be the preferable method for health care providers, but agreement limits mentioned in this study should be considered.

Metapopulation structure of the specialized herbivore Macrosiphoniella tanacetaria (Homoptera, Aphididae).

PubMed

Massonnet, Blandine; Simon, Jean-Christophe; Weisser, Wolfgang W

2002-12-01

We investigated population dynamics, genetic diversity and spatial structure in the aphid species Macrosiphoniella tanacetaria, a specialist herbivore feeding on tansy, Tanacetum vulgare. Tansy plants (genets) consist of many shoots (ramets), and genets are grouped in sites. Thus, aphids feeding on tansy can cluster at the level of ramets, genets and sites. We studied aphid population dynamics in 1997 and 2001 and found that within sites: (i). at any time, aphids used only a fraction of the available ramets and genets; (ii). at the level of ramets, most aphid colonies survived only one week; (iii). at the level of genets, mean survival time was less than 4 weeks; and (iv). colonization and extinction events occurred throughout the season. We sampled aphids in seven sites in the Alsace region, France (4-45 km apart) and two sites in Germany in 1999 to study genetic structure within and between populations. Genetic analyses using nine microsatellite loci showed that: (i). genotypic variability was high, (ii). none of the populations was in Hardy-Weinberg equilibrium, (iii). heterozygote deficits and linkage disequilibria were frequent, and (iv). all populations were genetically differentiated, even at a small geographical scale. Renewed sampling of the Alsace sites in 2001 showed that three populations had become extinct and significant genetic changes had occurred in the remaining four populations. The frequencies of extinction and colonization events at several spatial scales suggest a hierarchical metapopulation structure for M. tanacetaria. Frequent population turnover and drift are likely causes for the genetic differentiation of M. tanacetaria populations.

Next-generation sequencing showing potential leachate influence on bacterial communities around a landfill in China.

PubMed

Rajasekar, Adharsh; Sekar, Raju; Medina-Roldán, Eduardo; Bridge, Jonathan; Moy, Charles K S; Wilkinson, Stephen

2018-04-10

The impact of contaminated leachate on groundwater from landfills is well known, but the specific effects on bacterial consortia are less well-studied. Bacterial communities in a landfill and an urban site located in Suzhou, China, were studied using Illumina high-throughput sequencing. A total of 153 944 good-quality reads were produced and sequences assigned to 6388 operational taxonomic units. Bacterial consortia consisted of up to 16 phyla, including Proteobacteria (31.9%-94.9% at landfill, 25.1%-43.3% at urban sites), Actinobacteria (0%-28.7% at landfill, 9.9%-34.3% at urban sites), Bacteroidetes (1.4%-25.6% at landfill, 5.6%-7.8% at urban sites), Chloroflexi (0.4%-26.5% at urban sites only), and unclassified bacteria. Pseudomonas was the dominant (67%-93%) genus in landfill leachate. Arsenic concentrations in landfill raw leachate (RL) (1.11 × 10 3 μg/L) and fresh leachate (FL2) (1.78 × 10 3 μg/L) and mercury concentrations in RL (10.9 μg/L) and FL2 (7.37 μg/L) exceeded Chinese State Environmental Protection Administration standards for leachate in landfills. The Shannon diversity index and Chao1 richness estimate showed RL and FL2 lacked richness and diversity when compared with other samples. This is consistent with stresses imposed by elevated arsenic and mercury and has implications for ecological site remediation by bioremediation or natural attenuation.

A Comparative Approach for Ranking Contaminated Sites Based on the Risk Assessment Paradigm Using Fuzzy PROMETHEE

NASA Astrophysics Data System (ADS)

Zhang, Kejiang; Kluck, Cheryl; Achari, Gopal

2009-11-01

A ranking system for contaminated sites based on comparative risk methodology using fuzzy Preference Ranking Organization METHod for Enrichment Evaluation (PROMETHEE) was developed in this article. It combines the concepts of fuzzy sets to represent uncertain site information with the PROMETHEE, a subgroup of Multi-Criteria Decision Making (MCDM) methods. Criteria are identified based on a combination of the attributes (toxicity, exposure, and receptors) associated with the potential human health and ecological risks posed by contaminated sites, chemical properties, site geology and hydrogeology and contaminant transport phenomena. Original site data are directly used avoiding the subjective assignment of scores to site attributes. When the input data are numeric and crisp the PROMETHEE method can be used. The Fuzzy PROMETHEE method is preferred when substantial uncertainties and subjectivities exist in site information. The PROMETHEE and fuzzy PROMETHEE methods are both used in this research to compare the sites. The case study shows that this methodology provides reasonable results.

A comparative approach for ranking contaminated sites based on the risk assessment paradigm using fuzzy PROMETHEE.

PubMed

Zhang, Kejiang; Kluck, Cheryl; Achari, Gopal

2009-11-01

A ranking system for contaminated sites based on comparative risk methodology using fuzzy Preference Ranking Organization METHod for Enrichment Evaluation (PROMETHEE) was developed in this article. It combines the concepts of fuzzy sets to represent uncertain site information with the PROMETHEE, a subgroup of Multi-Criteria Decision Making (MCDM) methods. Criteria are identified based on a combination of the attributes (toxicity, exposure, and receptors) associated with the potential human health and ecological risks posed by contaminated sites, chemical properties, site geology and hydrogeology and contaminant transport phenomena. Original site data are directly used avoiding the subjective assignment of scores to site attributes. When the input data are numeric and crisp the PROMETHEE method can be used. The Fuzzy PROMETHEE method is preferred when substantial uncertainties and subjectivities exist in site information. The PROMETHEE and fuzzy PROMETHEE methods are both used in this research to compare the sites. The case study shows that this methodology provides reasonable results.

Representativeness of the ground observational sites and up-scaling of the point soil moisture measurements

NASA Astrophysics Data System (ADS)

Chen, Jinlei; Wen, Jun; Tian, Hui

2016-02-01

Soil moisture plays an increasingly important role in the cycle of energy-water exchange, climate change, and hydrologic processes. It is usually measured at a point site, but regional soil moisture is essential for validating remote sensing products and numerical modeling results. In the study reported in this paper, the minimal number of required sites (NRS) for establishing a research observational network and the representative single sites for regional soil moisture estimation are discussed using the soil moisture data derived from the ;Maqu soil moisture observational network; (101°40‧-102°40‧E, 33°30‧-35°45‧N), which is supported by Chinese Academy of Science. Furthermore, the best up-scaling method suitable for this network has been studied by evaluating four commonly used up-scaling methods. The results showed that (1) Under a given accuracy requirement R ⩾ 0.99, RMSD ⩽ 0.02 m3/m3, NRS at both 5 and 10 cm depth is 10. (2) Representativeness of the sites has been validated by time stability analysis (TSA), time sliding correlation analysis (TSCA) and optimal combination of sites (OCS). NST01 is the most representative site at 5 cm depth for the first two methods; NST07 and NST02 are the most representative sites at 10 cm depth. The optimum combination sites at 5 cm depth are NST01, NST02, and NST07. NST05, NST08, and NST13 are the best group at 10 cm depth. (3) Linear fitting, compared with other three methods, is the best up-scaling method for all types of representative sites obtained above, and linear regression equations between a single site and regional soil moisture are established hereafter. ;Single site; obtained by OCS has the greatest up-scaling effect, and TSCA takes the second place. (4) Linear fitting equations show good practicability in estimating the variation of regional soil moisture from July 3, 2013 to July 3, 2014, when a large number of observed soil moisture data are lost.

Stratigraphy Identification with Emphasis to Shells Layer using 2-D Electrical Resistivity Method at Guar Kepah, Penang

NASA Astrophysics Data System (ADS)

Rosli, Najmiah; Mansor, Hafizuddin; Ismail, N. A.; Masnan, S. S. K.; Saidin, M.

2018-04-01

2-D electrical resistivity method was done at an archaeological site in Guar Kepah, Penang, to determine its stratigraphy with emphasis to shells layer. This study aims to guide the archaeological studies where many prehistoric findings are related to shells and also for engineering purposes as an archaeological gallery is to be built there. Results show that the area is composed of three unconsolidated soil strata where the uppermost layer is sandy-clay, followed by shells layer, and lastly sandy layer. The shells layer is undulating with similar thickness throughout the site, but thickens at the northern part of the study area. The depth of the shells layer however, is different at different parts of the site.

Gender differences in living with schizophrenia. A cross-sectional European multi-site study.

PubMed

Thornicroft, Graham; Leese, Morven; Tansella, Michele; Howard, Louise; Toulmin, Hilary; Herran, Andres; Schene, Aart

2002-10-01

The EPSILON project (European Psychistric Services: Inputs Linked to Outcomes and Needs) is a cross-sectional study of the clinical and social characteristics, needs, satisfaction with services, quality of life, and service utilisation and costs for people with schizophrenia in five European sites (Amsterdam, Copenhagen, London, Santander, and Verona). This study examined five hypotheses: (1) Men will have more total needs and more unmet needs for: 'accommodation', 'substance misuse', 'psychotic symptoms', 'harm to others', and 'sexual expression', whereas women will have more total needs and more unmet needs in the domains of 'childcare' and 'harm to self'. (2) Caregivers of male patients will show higher rates of psychological distress, and higher scores for 'supervision' and 'urging' than caregivers of female patients. (3) Male and female patients will show similar levels of satisfaction with services, both in total scores and subscores. (4) Male patients will show lower objective quality of life, but similar subjective quality of life compared with women. (5) Service utilization for men and women will differ, and patterns will vary by site. The results confirmed hypotheses 1 (in part) and 3, but failed to support hypotheses 2, 4 and 5. Graphical models were used to generate hypotheses for future research. The implications for planning separate services for male and female schizophrenic patients are discussed.

Structure-Energy Relationships of Halogen Bonds in Proteins.

PubMed

Scholfield, Matthew R; Ford, Melissa Coates; Carlsson, Anna-Carin C; Butta, Hawera; Mehl, Ryan A; Ho, P Shing

2017-06-06

The structures and stabilities of proteins are defined by a series of weak noncovalent electrostatic, van der Waals, and hydrogen bond (HB) interactions. In this study, we have designed and engineered halogen bonds (XBs) site-specifically to study their structure-energy relationship in a model protein, T4 lysozyme. The evidence for XBs is the displacement of the aromatic side chain toward an oxygen acceptor, at distances that are equal to or less than the sums of their respective van der Waals radii, when the hydroxyl substituent of the wild-type tyrosine is replaced by a halogen. In addition, thermal melting studies show that the iodine XB rescues the stabilization energy from an otherwise destabilizing substitution (at an equivalent noninteracting site), indicating that the interaction is also present in solution. Quantum chemical calculations show that the XB complements an HB at this site and that solvent structure must also be considered in trying to design molecular interactions such as XBs into biological systems. A bromine substitution also shows displacement of the side chain, but the distances and geometries do not indicate formation of an XB. Thus, we have dissected the contributions from various noncovalent interactions of halogens introduced into proteins, to drive the application of XBs, particularly in biomolecular design.

Clinical evaluation of near-infrared light transillumination in approximal dentin caries detection.

PubMed

Ozkan, Gokhan; Guzel, Kadriye Gorkem Ulu

2017-08-01

The objective of this clinical study was to compare conventional caries detection techniques, pen-type laser fluorescence device, and near-infrared light transillumination method in approximal dentin caries lesions. The study included 157 patients, aged 12-18, without any cavity in the posterior teeth. Two calibrated examiners carried out the assessments of selected approximal caries sites independently. After the assessments, the unopened sites were excluded and a total of 161 approximal sites were included in the study. When both the examiners arrived at a consensus regarding the presence of dentin caries, the detected lesions were opened with a conical diamond burr, the cavity extent was examined and validated (gold standard). Sensitivity, specificity, negative predictive value, positive predictive value, accuracy, and area under the ROC curve (Az) values among the caries detection methods were calculated. Bitewing radiography and near-infrared (NIR) light transillumination methods showed the highest sensitivity (0.83-0.82) and accuracy (0.82-0.80) among the methods. Visual inspection showed the lowest sensitivity (0.54). Laser fluorescence device and visual inspection showed nearly equal performance. Near-infrared light transillumination can be used as an alternative method to approximal dentin caries detection. Visual inspection and laser fluorescence device alone should not be used for approximal dentin caries.

CD, MCD and VTVH MCD Studies of Biferrous and Mixed-Valent myo-Inositol Oxygenase: Insights into Substrate Activation of O2 Reactivity

PubMed Central

Snyder, Rae Ana; Bell, Caleb B.; Diao, Yinghui; Krebs, Carsten; Bollinger, J. Martin; Solomon, Edward I.

2013-01-01

Myo-inositol oxygenase (MIOX) catalyzes the 4e− oxidation of myo-inositol (MI) to D-glucuronate using a substrate activated Fe(II)Fe(III) site. The biferrous and Fe(II)Fe(III) forms of MIOX were studied with circular dichroism (CD), magnetic circular dichroism (MCD), and variable temperature variable field (VTVH) MCD spectroscopies. The MCD spectrum of biferrous MIOX shows two ligand field (LF) transitions near 10,000 cm−1, split by ~2,000 cm−1, characteristic of 6 coordinate (6C) Fe(II) sites, indicating that the modest reactivity of the biferrous form toward O2 can be attributed to the saturated coordination of both irons. Upon oxidation to the Fe(II)Fe(III) state, MIOX shows two LF transitions in the ~10,000 cm−1 region, again implying a coordinatively saturated Fe(II) site. Upon MI binding, these split in energy to 5,200 cm−1 and 11,200 cm−1, showing that MI binding causes the Fe(II) to become coordinately unsaturated. VTVH MCD magnetization curves of unbound and MI-bound Fe(II)Fe(III) forms show that upon substrate binding, the isotherms become more nested, requiring that the exchange coupling and ferrous zero field splitting (ZFS) both decrease in magnitude. These results imply that MI binds to the ferric site, weakening the Fe(III)-μ-OH bond and strengthening the Fe(II)-μ-OH bond. This perturbation results in the release of a coordinated water from the Fe(II) that enables its O2 activation. PMID:24066857

A study in usability: redesigning a health sciences library's mobile site.

PubMed

Rosario, Jovy-Anne; Ascher, Marie T; Cunningham, Diana J

2012-01-01

A mobile site redesign was conducted at a medium-sized academic health sciences library with the goal of creating a site that meets the mobile information needs of its users. The redesign phases included (1) needs assessment, (2) usability testing, and (3) site design. The survey results showed that Apple devices were the most prevalent; the most desirable activities performed on a mobile site were searching for articles, accessing full-text articles and e-books, searching databases, and searching the catalog. These activities guided the development of the usability testing tasks and the redesign. All phases were completed within six months, and the total project cost was $50 for incentive purchases. Copyright © Taylor & Francis Group, LLC

Unravelling Site-Specific Photo-Reactions of Ethanol on Rutile TiO2(110)

PubMed Central

Hansen, Jonas Ø.; Bebensee, Regine; Martinez, Umberto; Porsgaard, Soeren; Lira, Estephania; Wei, Yinying; Lammich, Lutz; Li, Zheshen; Idriss, Hicham; Besenbacher, Flemming; Hammer, Bjørk; Wendt, Stefan

2016-01-01

Finding the active sites of catalysts and photo-catalysts is crucial for an improved fundamental understanding and the development of efficient catalytic systems. Here we have studied the photo-activated dehydrogenation of ethanol on reduced and oxidized rutile TiO2(110) in ultrahigh vacuum conditions. Utilizing scanning tunnelling microscopy, various spectroscopic techniques and theoretical calculations we found that the photo-reaction proceeds most efficiently when the reactants are adsorbed on regular Ti surface sites, whereas species that are strongly adsorbed at surface defects such as O vacancies and step edges show little reaction under reducing conditions. We propose that regular Ti surface sites are the most active sites in photo-reactions on TiO2. PMID:26915303

Logs and data from trenches across and near the Green Valley Fault at the Mason Road site, Fairfield, Solano County, California, 2006-2009

USGS Publications Warehouse

Lienkaemper, James J.; Sickler, Robert R.; Mahan, Shannon; Brown, Johnathan; Reidy, Liam M.; Kimball, Mindy A.

2012-01-01

The primary purpose of this report is to provide drafted field logs of exploratory trenches excavated across the Green Valley Fault in 2007 and 2009 that show evidence for four surface rupturing earthquakes in the past one thousand years. The site location and site detail are shown on sheet 1. The trench logs are shown on sheets 1, 2, and 3. We also provide radiocarbon laboratory dates used for chronological modeling of the earthquake history. Sheets 4 and 5 show additional data obtained in 2006–2009 to document data obtained in our studies of the long-term geologic slip rate on the Green Valley Fault. However, that effort ultimately did not prove feasible and no slip rate estimate resulted.

Reducing risk and increasing confidence of decision making at a lower cost: In-situ pXRF assessment of metal-contaminated sites.

PubMed

Rouillon, Marek; Taylor, Mark P; Dong, Chenyin

2017-10-01

This study evaluates the in-situ use of field portable X-ray Fluorescence (pXRF) for metal-contaminated site assessments, and assesses the advantages of increased sampling to reduce risk, and increase confidence of decision making at a lower cost. Five metal-contaminated sites were assessed using both in-situ pXRF and ex-situ inductively coupled plasma mass spectrometry (ICP-MS) analyses at various sampling resolutions. Twenty second in-situ pXRF measurements of Mn, Zn and Pb were corrected using a subset of parallel ICP-MS measurements taken at each site. Field and analytical duplicates revealed sampling as the major contributor (>95% variation) to measurement uncertainties. This study shows that increased sampling led to several benefits including more representative site characterisation, higher soil-metal mapping resolution, reduced uncertainty around the site mean, and reduced sampling uncertainty. Real time pXRF data enabled efficient, on-site decision making for further judgemental sampling, without the need to return to the site. Additionally, in-situ pXRF was more cost effective than the current approach of ex-situ sampling and ICP-MS analysis, even with higher sampling at each site. Lastly, a probabilistic site assessment approach was applied to demonstrate the advantages of integrating estimated measurement uncertainties into site reporting. Copyright © 2017 Elsevier Ltd. All rights reserved.

Floristic composition and plant succession on near-surface radioactive-waste-disposal facilities in the Los Alamos National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tierney, G.D.; Foxx, T.S.

1982-03-01

Since 1946, low-level radioactive waste has been buried in shallow landfills within the confines of the Los Alamos National Laboratory. Five of these sites were studied for plant composition and successional patterns by reconnaissance and vegetation mapping. The data show a slow rate of recovery for all sites, regardless of age, in both the pinon-juniper and ponderosa pine communities. The sites are not comparable in succession or composition because of location and previous land use. The two oldest sites have the highest species diversity and the only mature trees. All sites allowed to revegetate naturally tend to be colonized bymore » the same species that originally surrounded the sites. Sites on historic fields are colonized by the old field flora, whereas those in areas disturbed only by grazing are revegetated by the local native flora.« less

LHRH-pituitary plasma membrane binding: the presence of specific binding sites in other tissues.

PubMed

Marshall, J C; Shakespear, R A; Odell, W D

1976-11-01

Two specific binding sites for LHRH are present on plasma membranes prepared from rat and bovine anterior pituitary glands. One site is of high affinity (K = 2X108 1/MOL) and the second is of lower affinity (8-5X105 1/mol) and much greater capacity. Studies on membrane fractions prepared from other tissues showed the presence of a single specific site for LHRH. The kinetics and specificity of this site were similar to those of the lower affinity pituitary receptor. These results indicate that only pituitary membranes possess the higher affinity binding site and suggest that the low affinity site is not of physiological importance in the regulation of gonadotrophin secretion. After dissociation from membranes of non-pituitary tissues 125I-LHRH rebound to pituitary membrane preparations. Thus receptor binding per se does not result in degradation of LHRH and the function of these peripheral receptors remains obscure.

[Drusen characteristics after internal limiting membrane peeling].

PubMed

Lehmann, F; Jenisch, T; Helbig, H; Gamulescu, M A

2015-05-01

There are some reports showing isolated cases of drusen regression after pars plana vitrectomy (ppV) with peeling of the internal limiting membrane (iLM). Drusen characteristics after iLM peeling was investigated in this study. The data of 527 patients who had received iLM peeling between 2004 and 2012 were retrospectively collected and those patients with retinal drusen were selected for the study. Fundus photographs before and after vitrectomy due to a macular hole or epiretinal gliosis were compared and drusen arrangement in the peeling site was analyzed. The aim of the study was to show whether there was drusen regression 2-5 months after surgery. Out of the 527 patients 11 showed central macular drusen, 4 with confluent large drusen (> 63 µm diameter) and 7 with small hard drusen (≤ 63 µm diameter). One patient showed drusen regression after iLM peeling without any changes in the other eye and all other patients showed no differences in the drusen findings (n = 6) or even some additional drusen (n = 4) without drusen alterations in the other eye. The results of this study could not confirm some reports showing drusen regression after iLM peeling in the peeling site in general and there was only one single case of central drusen regression.

Estimating variation in a landscape simulation of forest structure.

Treesearch

S. Hummel; P. Cunningham

2006-01-01

Modern technology makes it easy to show how forested landscapes might change with time but it remains difficult to estimate how sampling error affects landscape simulation results. To address this problem we used two methods to project the area in late-sera1 forest (LSF) structure for the same 6070 hectare (ha) study site over 30 years. The site was stratified into...

Health-Related Messages about Physical Activity Promotion: An Analysis of Photographs on Social Networking Sites of Universities

ERIC Educational Resources Information Center

Martínez-Bello, Vladimir E.; Martínez-Rojas, Ángela; Molina-García, Javier

2017-01-01

The main aim of this study was to examine how different physical activity domains are represented on the official social media sites of Spanish universities, through a content analysis of the photographs. Our results show that the representation of different physical activity domains is not balanced. While the analysed images do promote a message…

Characterization of hydrology and water quality of Piceance Creek in the Alkali Flat area, Rio Blanco County, Colorado, March 2012

USGS Publications Warehouse

Thomas, Judith C.

2015-12-07

Water-quality samples were collected at five surface-water sites in December 2010 that were sampled as part of a previous USGS study in 2000. Water-quality data collected during December 2010 showed no appreciable difference from water-quality data collected during December 2000 at the five sites.

The regeneration of central hardwoods with emphasis on the effects of site quality and harvesting practice

Treesearch

G. R., Jr. Trimble

1973-01-01

This report is an attempt to integrate and summarize research results from studies made mostly in West Virginia and to show the relationship of site quality and cutting practices to hardwood reproduction, with special emphasis on species composition. Reproduction has been found satisfactory in numbers and distribution after both clearcutting and selection cutting, but...

Exploring the Usefulness of School Education about Risks on Social Network Sites: A Survey Study

ERIC Educational Resources Information Center

Vanderhoven, Ellen; Schellens, Tammy; Valcke, Martin

2013-01-01

The growing popularity of social network sites (SNS) is causing concerns about privacy and security, especially with teenagers, since they show various forms of unsafe behavior on SNS. It has been put forth by researchers, teachers, parents, and teenagers that school is ideally placed to educate teens about risks on SNS and to teach youngsters how…

Growth data for 29 elevational transect years from the California study of ponderosa pine

Treesearch

M. Thompson Conkle

1973-01-01

Ponderosa pine progenies from parents restricted in latitude but spanning 7.000 feet of elevation show significant growth differences in plantations at low-, mid-, and high-elevation test sites. At low- and mid-elevation sites tree heights and diameters of progenies from high-elevation parents were the smallest; those from the low-elevation parents, intermediate; and...

Prevalence and site preferences of heterophyid metacercariae in Tilapia zilli from Ismalia fresh water canal, Egypt.

PubMed

Ibrahim, M M; Soliman, M F M

2010-09-01

Factors affecting prevalence and site preferences of heterophyid metacercariae (MC) were investigated in this study. A total of 173 specimens of a freshwater fish, Tilapia zilli were collected during autumn 2008, winter 2009 and summer 2009, from Ismailia fresh water canal, Egypt. Results showed that the total prevalence of heterophyid MC was 95.37%. The heterophyid MC consisted of Haplorchis yokogawi (47.4%), Pygidiopsis genata (21.4%), and Phagicola ascolonga (93.64%). H. yokogawi MC was detected in striated muscles, P. ascolonga in liver and kidney while, P. genata was detected in muscles, liver and kidney. The aggregation indices showed that all MC were aggregated and the P. genata was the most highly aggregated followed by H. yokogawi and then P. ascolonga. Responses of the heterophyid MC to host sex, weight and season greatly varied according to species of MC. Different responses of interaction for heterophyid MC intensity were found by GLIM analysis and this variation dependant on the type of infection (single or mixed infections). Factors affecting site preference of heterophid MC infection were discussed and further studies in other locations are required to examine the factors affecting site preference.

Remarkably constant PAH concentrations in Swiss soils over the last 30 years.

PubMed

Gubler, Andreas; Wächter, Daniel; Blum, Franziska; Bucheli, Thomas D

2015-10-01

Although polycyclic aromatic hydrocarbons (PAH) are of concern due to their carcinogenic, mutagenic, and teratogenic properties and their ubiquitous occurrence in environmental compartments, only few studies assessed the temporal evolutions of PAH contents of soils over extended time periods. The Swiss Soil Monitoring Network NABO runs long-term monitoring sites resampled every five years since the 1980s. In the present study, soil (0-20 cm) samples collected from 1985 through 2013 at 25 selected monitoring sites were analysed for the 16 priority PAH according to the U.S. EPA and five PAH marker substances. We observed divergent trends for light PAH, such as naphthalene and phenanthrene, compared with heavy PAH, such as benzo[a]pyrene and benzo[ghi]perylene. Whereas the former showed decreasing concentrations since the late 1980s, no significant trends were found for the latter. Furthermore, the analyses showed that naphthalene contents decreased most strongly at rural sites featuring low population densities, while phenanthrene contents generally decreased most strongly at semi-rural sites. The deviating evolutions of light and heavy PAH were mainly attributed to their differing physico-chemical properties. Temporal evolutions in soils contradict emission inventory data suggesting PAH emissions to decline since the 1980s.

Changes in Nematode Communities in Different Physiographic Sites of the Condor Seamount (North-East Atlantic Ocean) and Adjacent Sediments

PubMed Central

Zeppilli, Daniela; Bongiorni, Lucia; Serrão Santos, Ricardo; Vanreusel, Ann

2014-01-01

Several seamounts are known as ‘oases’ of high abundances and biomass and hotspots of biodiversity in contrast to the surrounding deep-sea environments. Recent studies have indicated that each single seamount can exhibit a high intricate habitat turnover. Information on alpha and beta diversity of single seamount is needed in order to fully understand seamounts contribution to regional and global biodiversity. However, while most of the seamount research has been focused on summits, studies considering the whole seamount structure are still rather poor. In the present study we analysed abundance, biomass and diversity of nematodes collected in distinct physiographic sites and surrounding sediments of the Condor Seamount (Azores, North-East Atlantic Ocean). Our study revealed higher nematode biomass in the seamount bases and values 10 times higher in the Condor sediments than in the far-field site. Although biodiversity indices did not showed significant differences comparing seamount sites and far-field sites, significant differences were observed in term of nematode composition. The Condor summit harboured a completely different nematode community when compared to the other seamount sites, with a high number of exclusive species and important differences in term of nematode trophic diversity. The oceanographic conditions observed around the Condor Seamount and the associated sediment mixing, together with the high quality of food resources available in seamount base could explain the observed patterns. Our results support the hypothesis that seamounts maintain high biodiversity through heightened beta diversity and showed that not only summits but also seamount bases can support rich benthic community in terms of standing stocks and diversity. Furthermore functional diversity of nematodes strongly depends on environmental conditions link to the local setting and seamount structure. This finding should be considered in future studies on seamounts, especially in view of the potential impacts due to current and future anthropogenic threats. PMID:25541988

Decreased Surgical Site Infection Rate in Hysterectomy: Effect of a Gynecology-Specific Bundle.

PubMed

Andiman, Sarah E; Xu, Xiao; Boyce, John M; Ludwig, Elizabeth M; Rillstone, Heidi R W; Desai, Vrunda B; Fan, Linda L

2018-06-01

We implemented a hysterectomy-specific surgical site infection prevention bundle after a higher-than-expected surgical site infection rate was identified at our institution. We evaluate how this bundle affected the surgical site infection rate, length of hospital stay, and 30-day postoperative readmission rate. This is a quality improvement study featuring retrospective analysis of a prospectively implemented, multidisciplinary team-designed surgical site infection prevention bundle that consisted of chlorhexidine-impregnated preoperative wipes, standardized aseptic surgical preparation, standardized antibiotic dosing, perioperative normothermia, surgical dressing maintenance, and direct feedback to clinicians when the protocol was breached. There were 2,099 hysterectomies completed during the 33-month study period. There were 61 surgical site infections (4.51%) in the pre-full bundle implementation period and 14 (1.87%) in the post-full bundle implementation period; we found a sustained reduction in the proportion of patients experiencing surgical site infection during the last 8 months of the study period. After adjusting for clinical characteristics, patients who underwent surgery after full implementation were less likely to develop a surgical site infection (adjusted odds ratio [OR] 0.46, P=.01) than those undergoing surgery before full implementation. Multivariable regression analysis showed no statistically significant difference in postoperative days of hospital stay (adjusted mean ratio 0.95, P=.09) or rate of readmission for surgical site infection-specific indication (adjusted OR 2.65, P=.08) between the before and after full-bundle implementation periods. The multidisciplinary implementation of a gynecologic perioperative surgical site infection prevention bundle was associated with a significant reduction in surgical site infection rate in patients undergoing hysterectomy.

Trace elements and organic compounds in sediment and fish tissue from the Great Salt Lake basins, Utah, Idaho, and Wyoming, 1998-99

USGS Publications Warehouse

Waddell, Kidd M.; Giddings, Elise M.

2004-01-01

A study to determine the occurrence and distribution of trace elements, organochlorine pesticides, polychlorinated biphenyls (PCBs), and semivolatile organic compounds in sediment and in fish tissue was conducted in the Great Salt Lake Basins study unit of the National Water-Quality Assessment (NAWQA) program during 1998-99. Streambed-sediment and fish-tissue samples were collected concurrently at 11 sites and analyzed for trace-element concentration. An additional four sites were sampled for streambed sediment only and one site for fish tissue only. Organic compounds were analyzed from streambed-sediment and fish-tissue samples at 15 sites concurrently.Bed-sediment cores from lakes, reservoirs, and Farmington Bay collected by the NAWQA program in 1998 and by other researchers in 1982 were used to examine historical trends in trace-element concentration and to determine anthropogenic sources of contaminants. Cores collected in 1982 from Mirror Lake, a high-mountain reference location, showed an enrichment of arsenic, cadmium, copper, lead, tin, and zinc in the surface sediments relative to the deeper sediments, indicating that enrichment likely began after about 1900. This enrichment was attributed to atmospheric deposition during the period of metal-ore mining and smelting. A core from Echo Reservoir, in the Weber River Basin, however, showed a different pattern of trace-element concentration that was attributed to a local source. This site is located downstream from the Park City mining district, which is the most likely historical source of trace elements. Cores collected in 1998 from Farmington Bay show that the concentration of lead began to increase after 1842 and peaked during the mid-1980s and has been in decline since. Recent sediments deposited during 1996-98 indicate a 41- to 62-percent reduction since the peak in the mid-1980s.The concentration of trace elements in streambed sediment was greatest at sites that have been affected by historic mining, including sites on Little Cottonwood Creek in the Jordan River basin, Silver Creek in the Weber River basin, and the Weber River below the confluence with Silver Creek. There was significant correlation of lead concentrations in streambed sediment and fish tissue, but other trace elements did not correlate well. Streambed sediment and fish tissue collected from sites in the Bear River basin, which is predominantly rangeland and agriculture, generally had low concentrations of most elements.Sediment-quality guidelines were used to assess the relative toxicity of streambed-sediment sites to aquatic communities. Sites affected by mining exceeded the Probable Effect Concentration (PEC), the concentration at which it is likely there will be a negative effect on the aquatic community, for arsenic, cadmium, copper, lead, silver, mercury, and zinc. Sites that were not affected by mining did not exceed these criteria. Concentrations of trace elements in samples collected from the Great Salt Lake Basins study unit (GRSL) are high compared to those of samples collected nationally with the NAWQA program. Nine of 15 streambed-sediment samples and 11 of 14 fish-tissue samples had concentrations of at least one trace element greater than the concentration of 90 percent of the samples collected nationally during 1993-2000.Organic compounds that were examined in streambed sediment and fish-tissue samples also were examined in bed-sediment cores. A bed-sediment core from Farmington Bay of Great Salt Lake showed an increase in total polycyclic aromatic hydrocarbon (PAH) concentrations coincident with the increase in population in Salt Lake Valley, which drains into this bay. Analysis of streambed-sediment samples showed that the highest concentrations of PAHs were detected at urban sites, including two sites in the lower Jordan River (the Jordan River flows into Farmington Bay), the Weber River at Ogden Bay, and the Provo River near Provo. Other organic compounds detected in streambed sediment in the lower Jordan River were PCBs, DDT compounds, and chlordane compounds.Organic compounds were detected more frequently in fish tissue than in streambed sediment. Chlordane compounds and PCBs were detected more frequently at urban sites. DDT compounds were detected at 13 of 15 sites including urban and agricultural sites. Concentrations of total DDT in fish tissue exceeded the guideline for protection of fish-eating wildlife at two urban sites. The concentration of organic compounds in the GRSL study unit is low compared with that of samples collected nationally.

Performance Evaluation and Community Application of Low-Cost Sensors for Ozone and Nitrogen Dioxide

PubMed Central

Duvall, Rachelle M.; Long, Russell W.; Beaver, Melinda R.; Kronmiller, Keith G.; Wheeler, Michael L.; Szykman, James J.

2016-01-01

This study reports on the performance of electrochemical-based low-cost sensors and their use in a community application. CairClip sensors were collocated with federal reference and equivalent methods and operated in a network of sites by citizen scientists (community members) in Houston, Texas and Denver, Colorado, under the umbrella of the NASA-led DISCOVER-AQ Earth Venture Mission. Measurements were focused on ozone (O3) and nitrogen dioxide (NO2). The performance evaluation showed that the CairClip O3/NO2 sensor provided a consistent measurement response to that of reference monitors (r2 = 0.79 in Houston; r2 = 0.72 in Denver) whereas the CairClip NO2 sensor measurements showed no agreement to reference measurements. The CairClip O3/NO2 sensor data from the citizen science sites compared favorably to measurements at nearby reference monitoring sites. This study provides important information on data quality from low-cost sensor technologies and is one of few studies that reports sensor data collected directly by citizen scientists. PMID:27754370

Multisite longitudinal reliability of tract-based spatial statistics in diffusion tensor imaging of healthy elderly subjects.

PubMed

Jovicich, Jorge; Marizzoni, Moira; Bosch, Beatriz; Bartrés-Faz, David; Arnold, Jennifer; Benninghoff, Jens; Wiltfang, Jens; Roccatagliata, Luca; Picco, Agnese; Nobili, Flavio; Blin, Oliver; Bombois, Stephanie; Lopes, Renaud; Bordet, Régis; Chanoine, Valérie; Ranjeva, Jean-Philippe; Didic, Mira; Gros-Dagnac, Hélène; Payoux, Pierre; Zoccatelli, Giada; Alessandrini, Franco; Beltramello, Alberto; Bargalló, Núria; Ferretti, Antonio; Caulo, Massimo; Aiello, Marco; Ragucci, Monica; Soricelli, Andrea; Salvadori, Nicola; Tarducci, Roberto; Floridi, Piero; Tsolaki, Magda; Constantinidis, Manos; Drevelegas, Antonios; Rossini, Paolo Maria; Marra, Camillo; Otto, Josephin; Reiss-Zimmermann, Martin; Hoffmann, Karl-Titus; Galluzzi, Samantha; Frisoni, Giovanni B

2014-11-01

Large-scale longitudinal neuroimaging studies with diffusion imaging techniques are necessary to test and validate models of white matter neurophysiological processes that change in time, both in healthy and diseased brains. The predictive power of such longitudinal models will always be limited by the reproducibility of repeated measures acquired during different sessions. At present, there is limited quantitative knowledge about the across-session reproducibility of standard diffusion metrics in 3T multi-centric studies on subjects in stable conditions, in particular when using tract based spatial statistics and with elderly people. In this study we implemented a multi-site brain diffusion protocol in 10 clinical 3T MRI sites distributed across 4 countries in Europe (Italy, Germany, France and Greece) using vendor provided sequences from Siemens (Allegra, Trio Tim, Verio, Skyra, Biograph mMR), Philips (Achieva) and GE (HDxt) scanners. We acquired DTI data (2 × 2 × 2 mm(3), b = 700 s/mm(2), 5 b0 and 30 diffusion weighted volumes) of a group of healthy stable elderly subjects (5 subjects per site) in two separate sessions at least a week apart. For each subject and session four scalar diffusion metrics were considered: fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD) and axial (AD) diffusivity. The diffusion metrics from multiple subjects and sessions at each site were aligned to their common white matter skeleton using tract-based spatial statistics. The reproducibility at each MRI site was examined by looking at group averages of absolute changes relative to the mean (%) on various parameters: i) reproducibility of the signal-to-noise ratio (SNR) of the b0 images in centrum semiovale, ii) full brain test-retest differences of the diffusion metric maps on the white matter skeleton, iii) reproducibility of the diffusion metrics on atlas-based white matter ROIs on the white matter skeleton. Despite the differences of MRI scanner configurations across sites (vendors, models, RF coils and acquisition sequences) we found good and consistent test-retest reproducibility. White matter b0 SNR reproducibility was on average 7 ± 1% with no significant MRI site effects. Whole brain analysis resulted in no significant test-retest differences at any of the sites with any of the DTI metrics. The atlas-based ROI analysis showed that the mean reproducibility errors largely remained in the 2-4% range for FA and AD and 2-6% for MD and RD, averaged across ROIs. Our results show reproducibility values comparable to those reported in studies using a smaller number of MRI scanners, slightly different DTI protocols and mostly younger populations. We therefore show that the acquisition and analysis protocols used are appropriate for multi-site experimental scenarios. Copyright © 2014 Elsevier Inc. All rights reserved.

Evaluation of forest structure, biomass and carbon sequestration in subtropical pristine forests of SW China.

PubMed

Nizami, Syed Moazzam; Yiping, Zhang; Zheng, Zheng; Zhiyun, Lu; Guoping, Yang; Liqing, Sha

2017-03-01

Very old natural forests comprising the species of Fagaceae (Lithocarpus xylocarpus, Castanopsis wattii, Lithocarpus hancei) have been prevailing since years in the Ailaoshan Mountain Nature Reserve (AMNR) SW China. Within these forest trees, density is quite variable. We studied the forest structure, stand dynamics and carbon density at two different sites to know the main factors which drives carbon sequestration process in old forests by considering the following questions: How much is the carbon density in these forest trees of different DBH (diameter at breast height)? How much carbon potential possessed by dominant species of these forests? How vegetation carbon is distributed in these forests? Which species shows high carbon sequestration? What are the physiochemical properties of soil in these forests? Five-year (2005-2010) tree growth data from permanently established plots in the AMNR was analysed for species composition, density, stem diameter (DBH), height and carbon (C) density both in aboveground and belowground vegetation biomass. Our study indicated that among two comparative sites, overall 54 species of 16 different families were present. The stem density, height, C density and soil properties varied significantly with time among the sites showing uneven distribution across the forests. Among the dominant species, L. xylocarpus represents 30% of the total carbon on site 1 while C. wattii represents 50% of the total carbon on site 2. The average C density ranged from 176.35 to 243.97 t C ha -1 . The study emphasized that there is generous degree to expand the carbon stocking in this AMNR through scientific management gearing towards conservation of old trees and planting of potentially high carbon sequestering species on good site quality areas.

Neutron diffraction studies of some rare earth-transition metal deuterides

NASA Astrophysics Data System (ADS)

James, W. J.

1984-04-01

Neutron diffraction studies of the ternary alloy system Y6(Fel-xMnx)23 reveal that the unusual magnetic behavior upon substitution of Mn or Fe into the end members, is a consequence of atomic ordering wherein there is strong site preference of Mn for the f sub 2 sites and of Fe for the f sub 1 sites. In the Mn-rich compositions, Fe is found to have no spontaneous moments. Therefore, the long range magnetic ordering arises solely from Mn-Mn interactions. Upon substitution of Mn into the Fe-rich ternaries, the Fe moments are considerably reduced. Neutron diffraction studies of Y6Mn23D23 show that a transition occurs below 180K from a fcc structure to a primitive tetragonal structure, space group P4/mmm with the onset of antiferromagnetic ordering. The Mn moments are directed along the c-axis. The transition probably results from atomic ordering of the D atoms at low temperature which induces c axis magnetic ordering. The question of the appropriate space group of LaNi4.5Al0.5D4.5, P6/mmm or P3/m has been resolved by a careful refinement and analysis of neutron diffraction data. The preferred space group is P6/mmm. Neutron powder diffraction and thermal magnetization measurements on small single crystals of ErNi3, ErCo3, and ErFe3 (space group R3m) show that the magnetocrystalline properties are a consequence of competing local site anisotropies between the two non-equivalent crystallographic sites of Er and two of the three non-equivalent sites of the 3d-transition metal.

Novel bone substitute material in alveolar bone healing following tooth extraction: an experimental study in sheep.

PubMed

Liu, Jinyi; Schmidlin, Patrick R; Philipp, Alexander; Hild, Nora; Tawse-Smith, Andrew; Duncan, Warwick

2016-07-01

Electrospun cotton wool-like nanocomposite (ECWN) is a novel synthetic bone substitute that incorporates amorphous calcium phosphate nanoparticles into a biodegradable synthetic copolymer poly(lactide-co-glycolide). The objectives of this study were to develop a tooth extraction socket model in sheep for bone graft research and to compare ECWN and bovine-derived xenograft (BX) in this model. Sixteen cross-bred female sheep were used. Bilateral mandibular premolars were extracted atraumatically. Second and third premolar sockets were filled (Latin-square allocation) with BX, ECWN or left unfilled. Resorbable collagen membranes were placed over BX and selected ECWN grafted sockets. Eight sheep per time period were sacrificed after 8 and 16 weeks. Resin-embedded undemineralised sections were analysed for descriptive histology and histomorphometric analyses. At 8 weeks, there were with no distinct differences in healing among the different sites. At 16 weeks, osseous healing followed a fine trabecular pattern in ECWN sites. Non-grafted sites showed thick trabeculae separated by large areas of fibrovascular connective tissue. In BX grafted sites, xenograft particles were surrounded by newly formed bone or fibrovascular connective tissue. There were no statistically significant differences in bone formation across the four groups. However, ECWN sites had significantly less residual graft material than BX sites at 16 weeks (P = 0.048). This first description of a tooth extraction socket model in sheep supports the utility of this model for bone graft research. The results of this study suggested that the novel material ECWN did not impede bone ingrowth into sockets and showed evidence of material resorption. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A DFT+U study of A-site and B-site substitution in BaFeO3-δ.

PubMed

Baiyee, Zarah Medina; Chen, Chi; Ciucci, Francesco

2015-09-28

BaFeO3-δ (BFO)-based perovskites have emerged as cheap and effective oxygen electrocatalysts for oxygen reduction reaction at high temperatures. The BFO cubic phase facilitates a high oxygen deficiency and is commonly stabilised by partial substitution. Understanding the electronic mechanisms of substitution and oxygen deficiency is key to rational material design, and can be realised through DFT analysis. In this work an in-depth first principle DFT+U study is undertaken to determine site distinctive characteristics for 12.5%, Y, La and Ce substitutions in BFO. In particular, it is shown that B-site doped structures exhibit a lower energy cost for oxygen vacancy formation relative to A site doping and pristine BFO. This is attributed to the stabilisation of holes in the oxygen sub-lattice and increased covalency of the Fe-O bonds of the FeO6 octahedra in B-site-substituted BFO. Charge analysis shows that A-site substitution amounts to donor doping and consequently impedes the accommodation of other donors (i.e. oxygen vacancies). However, A-site substitution may also exhibit a higher electronic conductivity due to less lattice distortion for oxygen deficiency compared to B-site doped structures. Furthermore, analysis of the local structural effects provides physical insight into stoichiometric expansions observed for this material.

Comparison of bone-conducted vibration for eliciting ocular vestibular-evoked myogenic potentials: forehead versus mastoid tapping.

PubMed

Tseng, Chia-Chen; Wang, Shou-Jen; Young, Yi-Ho

2012-02-01

This study compared bone-conducted vibration (BCV) stimuli at forehead (Fz) and mastoid sites for eliciting ocular vestibular-evoked myogenic potentials (oVEMPs). Prospective study. University hospital. Twenty healthy subjects underwent oVEMP testing via BCV stimuli at Fz and mastoid sites. Another 50 patients with unilateral Meniere's disease also underwent oVEMP testing. All healthy subjects showed clear oVEMPs via BCV stimulation regardless of the tapping sites. The right oVEMPs stimulated by tapping at the right mastoid had earlier nI and pI latencies and a larger nI-pI amplitude compared with those stimulated by tapping at the Fz and left mastoid. Similar trends were also observed in left oVEMPs. However, the asymmetry ratio did not differ significantly between the ipsilateral mastoid and Fz sites. Clinically, tapping at the Fz revealed absent oVEMPs in 28% of Meniere's ears, which decreased to 16% when tapping at the ipsilesional (hydropic) mastoid site, exhibiting a significant difference. Tapping at the ipsilateral mastoid site elicits earlier oVEMP latencies and larger oVEMP amplitudes when compared with tapping at the Fz site. Thus, tapping at the Fz site is suggested to screen for the otolithic function, whereas tapping at the ipsilesional mastoid site is suitable for evaluating residual otolithic function.

Search for Mars lander/rover/sample-return sites: A status review

NASA Technical Reports Server (NTRS)

Masursky, Harold; Dial, A. L., Jr.; Morris, E. C.; Strobell, M. E.; Applebee, D. J.; Chapman, M. G.

1988-01-01

Ten Mars sites were studied in the USA for four years. The sites are the Chasma Boreale (North Pole), Planum Australe (South Pole), Olympus Rupes, Mangala Valles, Memnonia Sulci, Candor Chasma, Kasel Valles, Nilosyrtis Mensae, Elysium Montes, and Apollinaris Patera. Seven sites are being studied by the USSR; their prime sites are located at the east mouth of Kasel Valles and near Uranius Patera. Thirteen geological maps of the first six USA sites are compiled and in review. Maps of the Mangala East and West sites at 1:1/2 million scale and a 1:2 million scale map show evidence of three episodes of small-channel formation interspersed with episodes of volcanism and tectonism that span the period from 3.5 to 0.6 b.y. ago. The tectonic and geological history of Mars, both ancient and modern, can be elucidated by sampling volcanic and fluvial geologic units at equatorial sites and layered deposits at polar sites. The evidence appears clear for multiple episodes of fluvial channeling, including some that are quite recent; this evidence contrasts with the theses of Baker and Partridge (1986) and many others that all channels are ancient. Verification of this hypothesis by Mars Observer will be an important step forward in the perception of the history of Mars.

Geochemistry of basement rocks of incoming plate (Cocos Ridge) from Sites U1381 and 1414, IODP Expeditions 334 and 344

NASA Astrophysics Data System (ADS)

Yan, Q.; Shi, X.

2015-12-01

The drilling sites of IODP 334 and 344 lie in the being subducted part of Cocos Ridge, offshore Costa Rica. Some seamount clusters distributed in the northwest side of the sites. Most scientists accepted that the Cocos ridge is intimately related to the activity of Galapagos plume (e.g., Hoernle et al., 2000, 2004, 2008). In this study we have selected some basaltic samples from U1381A, U1381C and U1414A (IODP 334 and 344) (Harris et al., 2015a, b) to carry out petrogenetic study. Major element compositions show that these basaltic rocks belong to sub-alkaline rocks, which is consistent with previous study on basalts from northern side of Cocos ridge. The characteristics of trace element composition are similar to that of EMORB, and the compositional differences in trace elements among samples reflect the influence of fractional crystallization. Sr-Nd-Pb isotopic compositions of these basaltic rocks show that there exist mantle heterogeneity beneath the Cocos ridge, and they may be the product of mixing between DMM/GSC and EMII. The new data show more enriched source feature than those from Galapagos hotspot (and its tracks) in previous study (Hoernle et al., 2000,2004), and slightly more enriched than those Miocene to Pliocene arc volcanics from Central America (Gazel et al., 2009). Partial melting model show that the parental basalts for these basaltic rocks may be produced by 13 to 28% partial melting of garnet pyroxenite. ReferencesGazel et al., 2009. G-cubed.10, Q02S11, doi:10.1029/2008GC002246.//Harris, R.N., Sakaguchi, A., Petronotis, K., and the Expedition 344 Scientists. 2015a. Input Site U1381. Proceedings of the Integrated Ocean Drilling Program, Volume 344//Harris, R.N., Sakaguchi, A., Petronotis, K., and the Expedition 344 Scientists. 2015b. Input Site U1414.Proceedings of the Integrated Ocean Drilling Program, Volume 344//Hoernle et al., 2000. Geology, 28(5),435-438//Hoernle et al., 2004. Geology, 32,697-700//Hoernle et al., 2008. Nature, 451,1094-1098 (This study was supported by National Natural Science Foundation of China (NSFC nos. 41296030 and 41322036, and IODP-China.)

Comprehensive profiling of retroviral integration sites using target enrichment methods from historical koala samples without an assembled reference genome

PubMed Central

Alquezar-Planas, David E.; Ishida, Yasuko; Courtiol, Alexandre; Timms, Peter; Johnson, Rebecca N.; Lenz, Dorina; Helgen, Kristofer M.; Roca, Alfred L.; Hartman, Stefanie

2016-01-01

Background. Retroviral integration into the host germline results in permanent viral colonization of vertebrate genomes. The koala retrovirus (KoRV) is currently invading the germline of the koala (Phascolarctos cinereus) and provides a unique opportunity for studying retroviral endogenization. Previous analysis of KoRV integration patterns in modern koalas demonstrate that they share integration sites primarily if they are related, indicating that the process is currently driven by vertical transmission rather than infection. However, due to methodological challenges, KoRV integrations have not been comprehensively characterized. Results. To overcome these challenges, we applied and compared three target enrichment techniques coupled with next generation sequencing (NGS) and a newly customized sequence-clustering based computational pipeline to determine the integration sites for 10 museum Queensland and New South Wales (NSW) koala samples collected between the 1870s and late 1980s. A secondary aim of this study sought to identify common integration sites across modern and historical specimens by comparing our dataset to previously published studies. Several million sequences were processed, and the KoRV integration sites in each koala were characterized. Conclusions. Although the three enrichment methods each exhibited bias in integration site retrieval, a combination of two methods, Primer Extension Capture and hybridization capture is recommended for future studies on historical samples. Moreover, identification of integration sites shows that the proportion of integration sites shared between any two koalas is quite small. PMID:27069793

Tracking Site-specific C-C Coupling of Formaldehyde Molecules on Rutile TiO2(110)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Ke; Xia, Yaobiao; Tang, Miru

2015-06-25

Direct imaging of site-specific reactions of individual mole-cules as a function of temperature is a long-sought goal in molecular science. Here, we report the direct visualization of molecular coupling of formaldehyde on reduced rutile TiO2(110) surfaces as we track the same set of molecules when the temperature is increased from 75 to 170 K using scanning tunneling microscope (STM). Our recent study showed that formaldehyde preferably adsorbs on bridging-bonded oxygen (Ob) vacancy (VO) defect site. Herein, images from the same area as the temperature is increased show that VO-bound formaldehyde couples with Ti-bound formaldehyde forming a diolate intermediate. Exposure ofmore » formaldehyde at room temperature leads to diolate as the majority species on the surface and no VO-bound formaldehyde is observed. The diolate species are the key reaction intermediates in the formation of ethylene reported in previous ensemble-averaged studies.« less

Characterization of rodent liver and kidney AVP receptors: pharmacologic evidence for species differences.

PubMed

Tahara, A; Tsukada, J; Ishii, N; Tomura, Y; Wada, K; Kusayama, T; Yatsu, T; Uchida, W; Tanaka, A

1999-10-22

Radioligand binding studies with [3H]vasopressin (AVP) were used to determine the affinities of AVP receptor agonists and antagonists for mouse liver and kidney plasma membrane preparations. Both membrane preparations exhibited one class of high-affinity binding site. AVP ligand binding inhibition studies confirmed that mouse liver binding sites belong to the V1A subtype while kidney binding sites belong to the V2 receptor subtype. The affinity of each ligand for mouse V1A receptors was very similar to that for rat V1A receptors, showing differences in Ki values of less than 3-fold. In contrast, several peptide (d(CH2)5Tyr(Me)AVP) and nonpeptide (OPC-21268 and SR 49059) ligands had different affinities for mouse and rat kidney V2 receptors, with differences in Ki values ranging from 14- to 17-fold. These results indicate that mouse and rat kidney V2 receptors show significant pharmacologic differences.

Prehistoric Human Adaptation to Tibetan Plateau Environment indicated by 151 site in the Qinghai Lake Basin

NASA Astrophysics Data System (ADS)

Zhang, Dongju; Dong, Guanghui; Wang, Qianqian; Ren, Xiaoyan; Chen, Fahu

2017-04-01

Current study indicates that Northeastern Tibetan Plateau (NETP) is one of the first widely occupied places by prehistory people on the Tibetan Plateau, which makes NETP very important to understand the human history on the plateau and human adaptation to high elevation environment. Hence, 151 site, a paleo- to Epi-Paleolithic site in the Qinghai Lake basin on NETP, is chosen to excavate. Thousands pieces of animal bones, hundreds pieces of stone artifacts and several possible hearths were unearthed and obtained during two excavation seasons. Carefully redating of the site shows that it was first occupied shortly around 15 ka BP, then reoccupied from 9000-6000 a BP more intensely. Preliminary study of the site suggest that the first appearance of human in Qinghai Lake basin is closely related to the amelioration of the Last Deglaciation and the prevalence of microlithic technology in North China, which may enlighten the study of early human migration on to whole plateau; however, the latter more intense human occupation in 151 site is not only closely related to the warm and stable early-mid Holocene climate but also provoked by early millet agriculture in neighbor low-elevation Loess plateau.

studying coastal geomorphological changes on beaches located near of the Rio Grande de Manatí Watershed, Puerto Rico (1977-2015): and its management implications.

NASA Astrophysics Data System (ADS)

Barreto, M.; Cabrera, N.; Torres, J.; Caraballo Álvarez, I. O.

2016-02-01

A study of beach geomorphology changes was conducted in beach systems located near to the river mouth of the Rio Grande de Manatí in the north-central coast of Puerto Rico Island (1977-2015). The main objective of this study was identify the role of river and land cover and land use changes (LCLUC) over changes in beach geomorphology. An integration of field work, remote sensing (historical aerial photos and multispectral images), Global Positioning Systems (GPS), Geographic Information Systems (GIS) and evaluation of published databanks (USGS water data, LCLUC) were used to generate and analyze data in this study. Results showed three different beach geomorphic systems along the study site. These are: 1) a wider terrigenous beach located westward to the river mouth; 2) a narrow mixed terrigenous and biogenic beach on the eastward site of the river mouth; and 3) a wide biogenic beach on the eastern site of the coastline. Historical shoreline changes showed that major loss of sand was observed along all beaches from 1995 to 1997 period (10 to 50 meters). Shift from accretion to erosion and vice versa were found in beach segments from 1971 to 1977, 1977-1985, 1985-1991, 1997-2003 and 2003-2010 periods, where major shoreline changes were identified mainly in the biogenic beach. LCLUC distribution showed a major reduction in agriculture land use (from 58% to 6%) from 1977 to 2010. This land was converted mainly to forest and rangeland during this period. Major flood events occurred in the study site from 1992 to 1995 may associated with major loss of sand on beaches in the study area. Detail association between shoreline changes and LCLUC/hydrological process will be defined during the second year of the project. This assessment is important to generate information to develop coastal management plans that helps community and ecosystems planners to be proactive during risk events in the area.

The serine 814 of TRPC6 is phosphorylated under unstimulated conditions.

PubMed

Bousquet, Simon M; Monet, Michael; Boulay, Guylain

2011-03-23

TRPC are nonselective cation channels involved in calcium entry. Their regulation by phosphorylation has been shown to modulate their routing and activity. TRPC6 activity increases following phosphorylation by Fyn, and is inhibited by protein kinase G and protein kinase C. A previous study by our group showed that TRPC6 is phosphorylated under unstimulated conditions in a human embryonic kidney cells line (HEK293). To investigate the mechanism responsible for this phosphorylation, we used a MS/MS approach combined with metabolic labeling and showed that the serine at position 814 is phosphorylated in unstimulated cells. The mutation of Ser(814) into Ala decreased basal phosphorylation but did not modify TRPC6 activity. Even though Ser(814) is within a consensus site for casein kinase II (CK2), we showed that CK2 is not involved in the phosphorylation of TRPC6 and does not modify its activity. In summary, we identified a new basal phosphorylation site (Ser(814)) on TRPC6 and showed that CK2 is not responsible for the phosphorylation of this site.

The Serine 814 of TRPC6 Is Phosphorylated under Unstimulated Conditions

PubMed Central

Bousquet, Simon M.; Monet, Michael; Boulay, Guylain

2011-01-01

TRPC are nonselective cation channels involved in calcium entry. Their regulation by phosphorylation has been shown to modulate their routing and activity. TRPC6 activity increases following phosphorylation by Fyn, and is inhibited by protein kinase G and protein kinase C. A previous study by our group showed that TRPC6 is phosphorylated under unstimulated conditions in a human embryonic kidney cells line (HEK293). To investigate the mechanism responsible for this phosphorylation, we used a MS/MS approach combined with metabolic labeling and showed that the serine at position 814 is phosphorylated in unstimulated cells. The mutation of Ser814 into Ala decreased basal phosphorylation but did not modify TRPC6 activity. Even though Ser814 is within a consensus site for casein kinase II (CK2), we showed that CK2 is not involved in the phosphorylation of TRPC6 and does not modify its activity. In summary, we identified a new basal phosphorylation site (Ser814) on TRPC6 and showed that CK2 is not responsible for the phosphorylation of this site. PMID:21448286

Hetero-site-specific X-ray pump-probe spectroscopy for femtosecond intramolecular dynamics

PubMed Central

Picón, A.; Lehmann, C. S.; Bostedt, C.; Rudenko, A.; Marinelli, A.; Osipov, T.; Rolles, D.; Berrah, N.; Bomme, C.; Bucher, M.; Doumy, G.; Erk, B.; Ferguson, K. R.; Gorkhover, T.; Ho, P. J.; Kanter, E. P.; Krässig, B.; Krzywinski, J.; Lutman, A. A.; March, A. M.; Moonshiram, D.; Ray, D.; Young, L.; Pratt, S. T.; Southworth, S. H.

2016-01-01

New capabilities at X-ray free-electron laser facilities allow the generation of two-colour femtosecond X-ray pulses, opening the possibility of performing ultrafast studies of X-ray-induced phenomena. Particularly, the experimental realization of hetero-site-specific X-ray-pump/X-ray-probe spectroscopy is of special interest, in which an X-ray pump pulse is absorbed at one site within a molecule and an X-ray probe pulse follows the X-ray-induced dynamics at another site within the same molecule. Here we show experimental evidence of a hetero-site pump-probe signal. By using two-colour 10-fs X-ray pulses, we are able to observe the femtosecond time dependence for the formation of F ions during the fragmentation of XeF2 molecules following X-ray absorption at the Xe site. PMID:27212390

Hetero-site-specific X-ray pump-probe spectroscopy for femtosecond intramolecular dynamics.

PubMed

Picón, A; Lehmann, C S; Bostedt, C; Rudenko, A; Marinelli, A; Osipov, T; Rolles, D; Berrah, N; Bomme, C; Bucher, M; Doumy, G; Erk, B; Ferguson, K R; Gorkhover, T; Ho, P J; Kanter, E P; Krässig, B; Krzywinski, J; Lutman, A A; March, A M; Moonshiram, D; Ray, D; Young, L; Pratt, S T; Southworth, S H

2016-05-23

New capabilities at X-ray free-electron laser facilities allow the generation of two-colour femtosecond X-ray pulses, opening the possibility of performing ultrafast studies of X-ray-induced phenomena. Particularly, the experimental realization of hetero-site-specific X-ray-pump/X-ray-probe spectroscopy is of special interest, in which an X-ray pump pulse is absorbed at one site within a molecule and an X-ray probe pulse follows the X-ray-induced dynamics at another site within the same molecule. Here we show experimental evidence of a hetero-site pump-probe signal. By using two-colour 10-fs X-ray pulses, we are able to observe the femtosecond time dependence for the formation of F ions during the fragmentation of XeF2 molecules following X-ray absorption at the Xe site.

Study of the impact on Salmonella of moving outdoor pigs to fresh land.

PubMed

Smith, R P; Andres, V; Dormer, L; Gosling, R; Oastler, C; Davies, R H

2017-07-01

Anecdotal evidence has suggested that outdoor-kept pigs show an improvement to health and productivity after being moved to a new site. This study explores whether Salmonella occurrence reduced and was sustained after moving to a new site. Nine farms were followed for a year in which four sampling visits were completed. The highest detection of Salmonella was from pooled faecal dropping from pigs, run-off/ pooled water, rodents and wild birds. Descriptive summaries showed that the prevalence of both all Salmonella and serovars of public health importance were lower at all visits after the move. Some variability was shown in results from individual farms, but a year after the move, six farms still maintained a lower prevalence. A risk factor model showed that the prevalence at visits 2 and 3 after the move was significantly lower than baseline, after accounting for a number of significant factors that were included in the model. These were sample type and seasonality (included as a priori), presence of coughing in the sampled group and Glasser's disease on the farm, and the use of tent or kennel accommodation. This finding provides important evidence that more frequent site moves may help reduce Salmonella prevalence in outdoor herds.

Roles of s3 site residues of nattokinase on its activity and substrate specificity.

PubMed

Wu, Shuming; Feng, Chi; Zhong, Jin; Huan, Liandong

2007-09-01

Nattokinase (Subtilisin NAT, NK) is a bacterial serine protease with high fibrinolytic activity. To probe their roles on protease activity and substrate specificity, three residues of S3 site (Gly(100), Ser(101) and Leu(126)) were mutated by site-directed mutagenesis. Kinetics parameters of 20 mutants were measured using tetrapeptides as substrates, and their fibrinolytic activities were determined by fibrin plate method. Results of mutation analysis showed that Gly(100) and Ser(101) had reverse steric and electrostatic effects. Residues with bulky or positively charged side chains at position 100 decreased the substrate binding and catalytic activity drastically, while residues with the same characters at position 101 could obviously enhance protease and fibrinolytic activity of NK. Mutation of Leu(126) might impair the structure of the active cleft and drastically decreased the activity of NK. Kinetics studies of the mutants showed that S3 residues were crucial to keep protease activity while they moderately affected substrate specificity of NK. The present study provided some original insight into the P3-S3 interaction in NK and other subtilisins, as well as showed successful protein engineering cases to improve NK as a potential therapeutic agent.

Carbon species in PM10 particle fraction at different monitoring sites.

PubMed

Godec, Ranka; Jakovljević, Ivana; Šega, Krešimir; Čačković, Mirjana; Bešlić, Ivan; Davila, Silvije; Pehnec, Gordana

2016-09-01

The aim of this study was to determine and compare the levels of elemental carbon (EC), organic carbon (OC) and polycyclic aromatic hydrocarbons (PAHs) mass concentrations in PM10 particles (particles with aerodynamic diameter less than 10 μm) between seasons (winter and summer) and at different monitoring sites (urban background and rural industrial). Daily samples of airborne particles were collected on pre-fired quartz fibre filters. PM10 mass concentrations were determined gravimetrically. Samples were analysed for OC and EC with the thermal/optical transmittance method (TOT) and for PAHs by high-performance liquid chromatography (HPLC) with a fluorescence detector. Measurements showed seasonal and spatial variations of mass concentrations for carbon species and for all of the measured PAHs (Flu, Pyr, Chry, BaA, BbF, BaP, BkF, BghiP and IP) in PM10 at the urban site and rural monitoring site described here. Diagnostic PAH ratios (Flu/(Flu + Pyr), BaA/(BaA + Cry), IP/(IP + BghiP), BaP/BghiP, IP/BghiP and BaP/(BaP + Chry)) make it possible to assess the sources of pollution, and these showed that diesel vehicles accounted for most pollution at the rural-industrial (RI) site in the summer, whereas coal and wood combustion were the causes of winter pollution. This difference between winter and summer PAH ratios were more expressed at the RI site than at the UB site because at the UB site the predominant heating fuel was gas. The OC/EC ratio yielded the same conclusion. Factor analysis showed that EC and OC originated from traffic at both sites, PAHs with 5 or more benzene rings originated from wood pellets industry or biomass burning, while Pyr and Flu originated from diesel combustion or as a consequence of different atmospheric behaviour - evaporation and participation in oxidation and photo oxidation processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Historical atmospheric pollution trends in Southeast Asia inferred from lake sediment records.

PubMed

Engels, S; Fong, L S R Z; Chen, Q; Leng, M J; McGowan, S; Idris, M; Rose, N L; Ruslan, M S; Taylor, D; Yang, H

2018-04-01

Fossil fuel combustion leads to increased levels of air pollution, which negatively affects human health as well as the environment. Documented data for Southeast Asia (SEA) show a strong increase in fossil fuel consumption since 1980, but information on coal and oil combustion before 1980 is not widely available. Spheroidal carbonaceous particles (SCPs) and heavy metals, such as mercury (Hg), are emitted as by-products of fossil fuel combustion and may accumulate in sediments following atmospheric fallout. Here we use sediment SCP and Hg records from several freshwater lentic ecosystems in SEA (Malaysia, Philippines, Singapore) to reconstruct long-term, region-wide variations in levels of these two key atmospheric pollution indicators. The age-depth models of Philippine sediment cores do not reach back far enough to date first SCP presence, but single SCP occurrences are first observed between 1925 and 1950 for a Malaysian site. Increasing SCP flux is observed at our sites from 1960 onward, although individual sites show minor differences in trends. SCP fluxes show a general decline after 2000 at each of our study sites. While the records show broadly similar temporal trends across SEA, absolute SCP fluxes differ between sites, with a record from Malaysia showing SCP fluxes that are two orders of magnitude lower than records from the Philippines. Similar trends in records from China and Japan represent the emergence of atmospheric pollution as a broadly-based inter-region environmental problem during the 20th century. Hg fluxes were relatively stable from the second half of the 20th century onward. As catchment soils are also contaminated with atmospheric Hg, future soil erosion can be expected to lead to enhanced Hg flux into surface waters. Copyright © 2018 Elsevier Ltd. All rights reserved.

Poor Prognosis of Lower Inner Quadrant in Lymph Node-negative Breast Cancer Patients Who Received No Chemotherapy: A Study Based on Nationwide Korean Breast Cancer Registry Database.

PubMed

Hwang, Ki-Tae; Kim, Jongjin; Kim, Eun-Kyu; Jung, Sung Hoo; Sohn, Guiyun; Kim, Seung Il; Jeong, Joon; Lee, Hyouk Jin; Park, Jin Hyun; Oh, Sohee

2017-07-01

We aimed to investigate the prognostic influence of primary tumor site on the survival of patients with breast cancer. Data of 63,388 patients with primary breast cancer from the Korean Breast Cancer Registry were analyzed. Primary tumor sites were classified into 5 groups: upper outer quadrant, lower outer quadrant, upper inner quadrant, lower inner quadrant (LIQ), and central portion. We analyzed overall survival (OS) and breast cancer-specific survival (BCSS) according to primary tumor site. Central portion and LIQ showed lower survival rates regarding both OS and BCSS compared with the other 3 quadrants (all P < .05) and hazard ratios were 1.267 (95% CI, 1.180-1.360, P < .001) and 1.215 (95% CI, 1.097-1.345, P < .001), respectively. Although central portion showed more unfavorable clinicopathologic features, LIQ showed more favorable features than the other 3 quadrants. Primary tumor site was a significant factor in univariate and multivariate analyses for OS and BCSS (all P < .001). For lymph node-negative patients, LIQ showed a worse OS than the other primary tumor sites in the subgroup with no chemotherapy (P < .001), but that effect disappeared in the subgroup with chemotherapy (P = .058). LIQ showed a worse prognosis despite having more favorable clinicopathologic features than other tumor locations and it was more prominent for lymph node-negative patients who received no chemotherapy. The hypothesis of possible hidden internal mammary node metastasis could be suggested to play a key role in LIQ lesions. Copyright © 2017 Elsevier Inc. All rights reserved.

New Synthesis and Tritium Labeling of a Selective Ligand for Studying High-affinity γ-Hydroxybutyrate (GHB) Binding Sites

PubMed Central

Vogensen, Stine B.; Marek, Aleš; Bay, Tina; Wellendorph, Petrine; Kehler, Jan; Bundgaard, Christoffer; Frølund, Bente; Pedersen, Martin H.F.; Clausen, Rasmus P.

2013-01-01

3-Hydroxycyclopent-1-enecarboxylic acid (HOCPCA, 1) is a potent ligand for the high-affinity GHB binding sites in the CNS. An improved synthesis of 1 together with a very efficient synthesis of [3H]-1 is described. The radiosynthesis employs in situ generated lithium trimethoxyborotritide. Screening of 1 against different CNS targets establishes a high selectivity and we demonstrate in vivo brain penetration. In vitro characterization of [3H]-1 binding shows high specificity to the high-affinity GHB binding sites. PMID:24053696

Investigation of Cr substitution in Co ferrite (CoCrxFe2-xO4) using Mossbauer spectroscopy

NASA Astrophysics Data System (ADS)

Krieble, K.; Lo, C. C. H.; Melikhov, Y.; Snyder, J. E.

2006-04-01

Substitution of other metals for Fe in cobalt ferrite has been proposed as a method to tailor the magnetic and magnetoelastic properties for sensor and actuator applications [H. Zheng et al., Science 303, 661 (2004)]. However, to understand the effect of Cr substitution, one needs atomic-level information on the local environments and interactions of the transition-metal ions. In this study, Mossbauer spectroscopy was used to investigate the local environments of the Fe atoms in these materials. A series of five powder samples with compositions CoCrxFe2-xO4 (x=0.0 to 0.8) was investigated using transmission geometry. Results show two distinct six-line hyperfine patterns, indicating Fe in A and B spinel sites. Increasing Cr concentration is seen to decrease the hyperfine field strength for both A and B sites, as well as increasing the width of those distributions. Results for Cr substitution show generally similar behavior to a prior study using Mn; however, Cr substitution has more pronounced effects: the hyperfine fields decrease and distribution widths increase at greater rates for Cr substitution, and the differences between A and B site behavior are more pronounced. Results are consistent with a model in which Cr has an even stronger B-site preference than Mn, and displaces more of the Co from the B to the A sites.

Exposure to toxic waste containing high concentrations of hydrogen sulphide illegally dumped in Abidjan, Côte d'Ivoire.

PubMed

Dongo, Kouassi; Tiembré, Issiaka; Koné, Blaise Atioumonou; Zurbrügg, Christian; Odermatt, Peter; Tanner, Marcel; Zinsstag, Jakob; Cissé, Guéladio

2012-09-01

On August 2006, a cargo ship illegally dumped 500 t of toxic waste containing high concentrations of hydrogen sulphide in numerous sites across Abidjan. Thousands of people became ill. Seventeen deaths were associated with toxic waste exposure. This study reports on environmental and health problems associated with the incident. A cross-sectional transect study was conducted in five waste dumping site areas. Of the households, 62.1% (n = 502) were exposed to the effects of the pollutants and 51.1% of the interviewed people (n = 2,368) in these households showed signs of poisoning. Most important symptoms were cough (37.1%), asthenia (33.1%), pruritus (29.9%) and nausea (29.1%). The health effects showed different frequencies in the five waste impact sites. Among the poisoned persons, 21.1% (n = 532) presented symptoms on the survey day (i.e., 4 months after incident). Transect sampling allowed to determine a radius of vulnerability to exposure of up to 3 km from the point of toxic waste disposal. The area of higher vulnerability is influenced by various environmental factors, such as size and severity of pollution site, duration of toxic waste pollution on the impact site and locally climatic conditions. The surveillance of effects on environment and human health is warranted to monitor the development.

Comparison of the historical record of earthquake hazard with seismic-hazard models for New Zealand and the continental United States

USGS Publications Warehouse

Stirling, M.; Petersen, M.

2006-01-01

We compare the historical record of earthquake hazard experienced at 78 towns and cities (sites) distributed across New Zealand and the continental United States with the hazard estimated from the national probabilistic seismic-hazard (PSH) models for the two countries. The two PSH models are constructed with similar methodologies and data. Our comparisons show a tendency for the PSH models to slightly exceed the historical hazard in New Zealand and westernmost continental United States interplate regions, but show lower hazard than that of the historical record in the continental United States intraplate region. Factors such as non-Poissonian behavior, parameterization of active fault data in the PSH calculations, and uncertainties in estimation of ground-motion levels from historical felt intensity data for the interplate regions may have led to the higher-than-historical levels of hazard at the interplate sites. In contrast, the less-than-historical hazard for the remaining continental United States (intraplate) sites may be largely due to site conditions not having been considered at the intraplate sites, and uncertainties in correlating ground-motion levels to historical felt intensities. The study also highlights the importance of evaluating PSH models at more than one region, because the conclusions reached on the basis of a solely interplate or intraplate study would be very different.

Context Dependent Effect of Landscape on the Occurrence of an Apex Predator across Different Climate Regions.

PubMed

Fujita, Go; Azuma, Atsuki; Nonaka, Jun; Sakai, Yoshiaki; Sakai, Hatsumi; Iseki, Fumitaka; Itaya, Hiroo; Fukasawa, Keita; Miyashita, Tadashi

2016-01-01

In studies of habitat suitability at landscape scales, transferability of species-landscape associations among sites are likely to be critical because it is often impractical to collect datasets across various regions. However, limiting factors, such as prey availability, are not likely to be constant across scales because of the differences in species pools. This is particularly true for top predators that are often the target for conservation concern. Here we focus on gray-faced buzzards, apex predators of farmland-dominated landscapes in East Asia. We investigated context dependency of "buzzard-landscape relationship", using nest location datasets from five sites, each differing in landscape composition. Based on the similarities of prey items and landscape compositions across the sites, we determined several alternative ways of grouping the sites, and then examined whether buzzard-landscape relationship change among groups, which was conducted separately for each way of grouping. As a result, the model of study-sites grouping based on similarities in prey items showed the smallest ΔAICc. Because the terms of interaction between group IDs and areas of broad-leaved forests and grasslands were selected, buzzard-landscape relationship showed a context dependency, i.e., these two landscape elements strengthen the relationship in southern region. The difference in prey fauna, which is associated with the difference in climate, might generate regional differences in the buzzard-landscape associations.

Mutation Rate Variation is a Primary Determinant of the Distribution of Allele Frequencies in Humans

PubMed Central

Pritchard, Jonathan K.

2016-01-01

The site frequency spectrum (SFS) has long been used to study demographic history and natural selection. Here, we extend this summary by examining the SFS conditional on the alleles found at the same site in other species. We refer to this extension as the “phylogenetically-conditioned SFS” or cSFS. Using recent large-sample data from the Exome Aggregation Consortium (ExAC), combined with primate genome sequences, we find that human variants that occurred independently in closely related primate lineages are at higher frequencies in humans than variants with parallel substitutions in more distant primates. We show that this effect is largely due to sites with elevated mutation rates causing significant departures from the widely-used infinite sites mutation model. Our analysis also suggests substantial variation in mutation rates even among mutations involving the same nucleotide changes. In summary, we show that variable mutation rates are key determinants of the SFS in humans. PMID:27977673

Origins of Allostery and Evolvability in Proteins: A Case Study.

PubMed

Raman, Arjun S; White, K Ian; Ranganathan, Rama

2016-07-14

Proteins display the capacity for adaptation to new functions, a property critical for evolvability. But what structural principles underlie the capacity for adaptation? Here, we show that adaptation to a physiologically distinct class of ligand specificity in a PSD95, DLG1, ZO-1 (PDZ) domain preferentially occurs through class-bridging intermediate mutations located distant from the ligand-binding site. These mutations provide a functional link between ligand classes and demonstrate the principle of "conditional neutrality" in mediating evolutionary adaptation. Structures show that class-bridging mutations work allosterically to open up conformational plasticity at the active site, permitting novel functions while retaining existing function. More generally, the class-bridging phenotype arises from mutations in an evolutionarily conserved network of coevolving amino acids in the PDZ family (the sector) that connects the active site to distant surface sites. These findings introduce the concept that allostery in proteins could have its origins not in protein function but in the capacity to adapt. Copyright © 2016 Elsevier Inc. All rights reserved.

Detection of canonical A-to-G editing events at 3′ UTRs and microRNA target sites in human lungs using next-generation sequencing

PubMed Central

Soundararajan, Ramani; Stearns, Timothy M.; Griswold, Anthony J.; Mehta, Arpit; Czachor, Alexander; Fukumoto, Jutaro; Lockey, Richard F.; King, Benjamin L.; Kolliputi, Narasaiah

2015-01-01

RNA editing is a post-transcriptional modification of RNA. The majority of these changes result from adenosine deaminase acting on RNA (ADARs) catalyzing the conversion of adenosine residues to inosine in double-stranded RNAs (dsRNAs). Massively parallel sequencing has enabled the identification of RNA editing sites in human transcriptomes. In this study, we sequenced DNA and RNA from human lungs and identified RNA editing sites with high confidence via a computational pipeline utilizing stringent analysis thresholds. We identified a total of 3,447 editing sites that overlapped in three human lung samples, and with 50% of these sites having canonical A-to-G base changes. Approximately 27% of the edited sites overlapped with Alu repeats, and showed A-to-G clustering (>3 clusters in 100 bp). The majority of edited sites mapped to either 3′ untranslated regions (UTRs) or introns close to splice sites; whereas, only few sites were in exons resulting in non-synonymous amino acid changes. Interestingly, we identified 652 A-to-G editing events in the 3′ UTR of 205 target genes that mapped to 932 potential miRNA target binding sites. Several of these miRNA edited sites were validated in silico. Additionally, we validated several A-to-G edited sites by Sanger sequencing. Altogether, our study suggests a role for RNA editing in miRNA-mediated gene regulation and splicing in human lungs. In this study, we have generated a RNA editome of human lung tissue that can be compared with other RNA editomes across different lung tissues to delineate a role for RNA editing in normal and diseased states. PMID:26486088

Detection of canonical A-to-G editing events at 3' UTRs and microRNA target sites in human lungs using next-generation sequencing.

PubMed

Soundararajan, Ramani; Stearns, Timothy M; Griswold, Anthony L; Mehta, Arpit; Czachor, Alexander; Fukumoto, Jutaro; Lockey, Richard F; King, Benjamin L; Kolliputi, Narasaiah

2015-11-03

RNA editing is a post-transcriptional modification of RNA. The majority of these changes result from adenosine deaminase acting on RNA (ADARs) catalyzing the conversion of adenosine residues to inosine in double-stranded RNAs (dsRNAs). Massively parallel sequencing has enabled the identification of RNA editing sites in human transcriptomes. In this study, we sequenced DNA and RNA from human lungs and identified RNA editing sites with high confidence via a computational pipeline utilizing stringent analysis thresholds. We identified a total of 3,447 editing sites that overlapped in three human lung samples, and with 50% of these sites having canonical A-to-G base changes. Approximately 27% of the edited sites overlapped with Alu repeats, and showed A-to-G clustering (>3 clusters in 100 bp). The majority of edited sites mapped to either 3' untranslated regions (UTRs) or introns close to splice sites; whereas, only few sites were in exons resulting in non-synonymous amino acid changes. Interestingly, we identified 652 A-to-G editing events in the 3' UTR of 205 target genes that mapped to 932 potential miRNA target binding sites. Several of these miRNA edited sites were validated in silico. Additionally, we validated several A-to-G edited sites by Sanger sequencing. Altogether, our study suggests a role for RNA editing in miRNA-mediated gene regulation and splicing in human lungs. In this study, we have generated a RNA editome of human lung tissue that can be compared with other RNA editomes across different lung tissues to delineate a role for RNA editing in normal and diseased states.

CD/MCD/VTVH-MCD Studies of Escherichia coli Bacterioferritin Support a Binuclear Iron Cofactor Site.

PubMed

Kwak, Yeonju; Schwartz, Jennifer K; Huang, Victor W; Boice, Emily; Kurtz, Donald M; Solomon, Edward I

2015-12-01

Ferritins and bacterioferritins (Bfrs) utilize a binuclear non-heme iron binding site to catalyze oxidation of Fe(II), leading to formation of an iron mineral core within a protein shell. Unlike ferritins, in which the diiron site binds Fe(II) as a substrate, which then autoxidizes and migrates to the mineral core, the diiron site in Bfr has a 2-His/4-carboxylate ligand set that is commonly found in diiron cofactor enzymes. Bfrs could, therefore, utilize the diiron site as a cofactor rather than for substrate iron binding. In this study, we applied circular dichroism (CD), magnetic CD (MCD), and variable-temperature, variable-field MCD (VTVH-MCD) spectroscopies to define the geometric and electronic structures of the biferrous active site in Escherichia coli Bfr. For these studies, we used an engineered M52L variant, which is known to eliminate binding of a heme cofactor but to have very minor effects on either iron oxidation or mineral core formation. We also examined an H46A/D50A/M52L Bfr variant, which additionally disrupts a previously observed mononuclear non-heme iron binding site inside the protein shell. The spectral analyses define a binuclear and an additional mononuclear ferrous site. The biferrous site shows two different five-coordinate centers. After O2 oxidation and re-reduction, only the mononuclear ferrous signal is eliminated. The retention of the biferrous but not the mononuclear ferrous site upon O2 cycling supports a mechanism in which the binuclear site acts as a cofactor for the O2 reaction, while the mononuclear site binds the substrate Fe(II) that, after its oxidation to Fe(III), migrates to the mineral core.

Multicriteria analysis for sources of renewable energy using data from remote sensing

NASA Astrophysics Data System (ADS)

Matejicek, L.

2015-04-01

Renewable energy sources are major components of the strategy to reduce harmful emissions and to replace depleting fossil energy resources. Data from remote sensing can provide information for multicriteria analysis for sources of renewable energy. Advanced land cover quantification makes it possible to search for suitable sites. Multicriteria analysis, together with other data, is used to determine the energy potential and socially acceptability of suggested locations. The described case study is focused on an area of surface coal mines in the northwestern region of the Czech Republic, where the impacts of surface mining and reclamation constitute a dominant force in land cover changes. High resolution satellite images represent the main input datasets for identification of suitable sites. Solar mapping, wind predictions, the location of weirs in watersheds, road maps and demographic information complement the data from remote sensing for multicriteria analysis, which is implemented in a geographic information system (GIS). The input spatial datasets for multicriteria analysis in GIS are reclassified to a common scale and processed with raster algebra tools to identify suitable sites for sources of renewable energy. The selection of suitable sites is limited by the CORINE land cover database to mining and agricultural areas. The case study is focused on long term land cover changes in the 1985-2015 period. Multicriteria analysis based on CORINE data shows moderate changes in mapping of suitable sites for utilization of selected sources of renewable energy in 1990, 2000, 2006 and 2012. The results represent map layers showing the energy potential on a scale of a few preference classes (1-7), where the first class is linked to minimum preference and the last class to maximum preference. The attached histograms show the moderate variability of preference classes due to land cover changes caused by mining activities. The results also show a slight increase in the more preferred classes for utilization of sources of renewable energy due to an increase area of reclaimed sites. Using data from remote sensing, such as the multispectral images and the CORINE land cover datasets, can reduce the financial resources currently required for finding and assessing suitable areas.

Assessment of Accumulation Processes at the Middle Pleistocene Site of Ambrona (Soria, Spain). Density and Orientation Patterns in Spatial Datasets Derived from Excavations Conducted from the 1960s to the Present

PubMed Central

Sánchez-Romero, Laura; Benito-Calvo, Alfonso; Pérez-González, Alfredo; Santonja, Manuel

2016-01-01

The Middle Pleistocene site of Ambrona (Soria, Spain) is a major reference for European Acheulean studies. The origin of the lithic and fauna accumulations at this site was first thought to be anthropogenic, but later studies showed that it was mainly natural. The first person to conduct excavations at the Ambrona site was the Marquis of Cerralbo, in 1914; other research groups followed in more recent times (the Howell & Freeman team and the Santonja & Pérez-González team). The digs yielded a great amount of information, but until now it had never been unified. In this paper, we compile all the available published and unpublished excavation documentation from the 1960s to the present. We use these maps and sections to present our spatial study of the LSM (Lower Stratigraphic Member) at the Ambrona site, combining stratigraphic criteria with GIS density and orientation analysis. This study enabled us to define the main concentrations of the LSM, providing an initial contribution to an assessment of their accumulation processes. Most of the concentrations preserved in the ancient shore area of the site display marked orientation patterns which coincide with the direction of the main water flows into the Ambrona wetland. However, random orientation patterns were observed in the central part of the site (Alpha concentration); they may be mostly preserved without undergoing transport processes, as previous taphonomic studies also confirm. PMID:28002424

Observations of Urban Heat Island Mitigation in California Coastal Cities due to a Sea Breeze Induced Coastal-Cooling ``REVERSE-REACTION'' to Global Warming

NASA Astrophysics Data System (ADS)

Bornstein, R. D.; Lebassi, B.; Gonzalez, J.

2010-12-01

The study evaluated long-term (1948-2005) air temperatures at over 300 urban and rural sites in California (CA) during summer (June-August, JJA). The aggregate CA results showed asymmetric warming, as daily min temperatures increased faster than daily max temperatures. The spatial distributions of daily max temperatures in the heavily urbanized South Coast and San Francisco Bay Area air basins, however, exhibited a complex pattern, with cooling at low-elevation (mainly urban) coastal-areas and warming at (mainly rural) inland areas. Previous studies have suggested that cooling summer max temperatures in CA were due to increased irrigation, coastal upwelling, or cloud cover. The current hypothesis, however, is that this temperature pattern arises from a “reverse-reaction” to greenhouse gas (GHG) induced global-warming. In this hypothesis, the global warming of inland areas resulted in an increased (cooling) sea breeze activity in coastal areas. That daytime summer coastal cooling was seen in coastal urban areas implies that urban heat island (UHI) warming was weaker than the reverse-reaction sea breeze cooling; if there was no UHI effect, then the cooling would have been even stronger. Analysis of daytime summer max temperatures at four adjacent pairs of urban and rural sites near the inland cooling-warming boundary, however, showed that the rural sites experienced cooling, while the urban sites showed warming due to UHI development. The rate of heat island growth was estimated as the sum of each urban warming rate and the absolute magnitude of the concurrent adjacent rural cooling rate. Values ranged from 0.12 to 0.55 K decade-1, and were proportional to changes in urban population and urban extent. As Sacramento, Modesto, Stockton, and San José have grown in aerial extent (21 to 59%) and population (40 to 118%), part of the observed increased JJA max values could be due to increased daytime UHI-intensity. Without UHI effects, the currently observed JJA SFBA coastal-cooling area might have expanded to include these sites, as the first three are adjacent to rural airport sites that showed cooling max-values due to increased marine influences. In addition, all urbanized sites with decreasing max-values would probably show even larger cooling rates if UHI effects could be removed. Significant societal impacts may result from this observed reverse-reaction to GHG-warming. Possible beneficial effects (especially during periods of UHI growth) include decreased maximum: O3 levels, per-capita energy requirements for cooling, and human thermal-stress levels.

Helicobacter pylori purine nucleoside phosphorylase shows new distribution patterns of open and closed active site conformations and unusual biochemical features.

PubMed

Narczyk, Marta; Bertoša, Branimir; Papa, Lucija; Vuković, Vedran; Leščić Ašler, Ivana; Wielgus-Kutrowska, Beata; Bzowska, Agnieszka; Luić, Marija; Štefanić, Zoran

2018-04-01

Even with decades of research, purine nucleoside phosphorylases (PNPs) are enzymes whose mechanism is yet to be fully understood. This is especially true in the case of hexameric PNPs, and is probably, in part, due to their complex oligomeric nature and a whole spectrum of active site conformations related to interactions with different ligands. Here we report an extensive structural characterization of the apo forms of hexameric PNP from Helicobacter pylori (HpPNP), as well as its complexes with phosphate (P i ) and an inhibitor, formycin A (FA), together with kinetic, binding, docking and molecular dynamics studies. X-ray structures show previously unseen distributions of open and closed active sites. Microscale thermophoresis results indicate that a two-site model describes P i binding, while a three-site model is needed to characterize FA binding, irrespective of P i presence. The latter may be related to the newly found nonstandard mode of FA binding. The ternary complex of the enzyme with P i and FA shows, however, that P i binding stabilizes the standard mode of FA binding. Surprisingly, HpPNP has low affinity towards the natural substrate adenosine. Molecular dynamics simulations show that P i moves out of most active sites, in accordance with its weak binding. Conformational changes between nonstandard and standard binding modes of nucleoside are observed during the simulations. Altogether, these findings show some unique features of HpPNP and provide new insights into the functioning of the active sites, with implications for understanding the complex mechanism of catalysis of this enzyme. The atomic coordinates and structure factors have been deposited in the Protein Data Bank: with accession codes 6F52 (HpPNPapo_1), 6F5A (HpPNPapo_2), 6F5I (HpPNPapo_3), 5LU0 (HpPNP_PO4), 6F4W (HpPNP_FA) and 6F4X (HpPNP_PO4_FA). Purine nucleoside orthophosphate ribosyl transferase, EC2.4.2.1, UniProtID: P56463. © 2018 Federation of European Biochemical Societies.

Statistical analysis of $sup 239-240$Pu and $sup 241$Am contamination of soil and vegetation on NAEG study sites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilbert, R.O.; Eberhardt, L.L.; Fowler, E.B.

Reported here are results of the statistical design and analysis work conducted during Calendar Year 1974 for the Nevada Applied Ecology Group (NAEG) at plutonium study sites on the Nevada Test Site (NTS) and the Tonopah Test Range (TTR). Estimates of $sup 239-240$Pu inventory in surface soil (0 to 5-cm depth) are given for each of the NAEG intensive study sites, together with activity maps based on FIDLER surveys showing the field areas to which these estimates apply. There is evidence of a preliminary nature to suggest that the plutonium present in surface soil may be covered by a thinmore » (less than 2.5 cm) layer of soil whose alpha activity is considerably less than that directly below. Computer-drawn $sup 239-240$Pu concentration contours and three-dimensional surfaces in soil and vegetation are given for Area 13 and GMX as a first attempt at estimating the geographical distribution of $sup 239-240$Pu at these sites. (CH)« less

Site attraction as a representation of heritage tourism: Case study of Gunung Padang Site, Cianjur, West - Java

NASA Astrophysics Data System (ADS)

Subakti, A. G.; Pratomo, Aditya; Triana, Ika; Khrisnanto, Iwan

2018-03-01

Heritage Tourism is used for experiencing the heritage of city, region, state or country. This travel enables the tourist to learn about local customs, traditions, history and culture. One of the tourist attractions in Cianjur, where an ancient historical megalithic site named Situs Gunung Padang could be found. Situs Gunung Padang which consists of five terraces and five levels, completely built stones. This site is the largest megalithic site in Southeast Asia. There is an enormous tourism potential owned by this site because it expresses and preserving ancient Sundanese cultural in the megalithic era. But the potential of this site seems haven’t made as a tourist attraction compared with Borobudur or Prambanan Temple. The purpose of this research is to analyze the existence of Gunung Padang site as a heritage tourism with SWOT approach to discover what factors need to be repaired. The result of this research is showing that Gunung Padang site has a huge potential if the regional governments and the locals can contribute to preserve and making this site as a tourist attraction.

Impacts of a Rural Subdivision on Groundwater Quality: Results of Long-Term Monitoring.

PubMed

Rayne, Todd W; Bradbury, Kenneth R; Krause, Jacob J

2018-03-30

A rural subdivision in south central Wisconsin was instrumented with monitoring wells and lysimeters before, during, and after its construction to examine the impacts of the unsewered subdivision on groundwater quality and quantity. Prior to construction, the 78-acre (32 ha) site was farmland. Sixteen homes were constructed beginning in 2003. Initial monitoring from 2002 to 2005 showed that groundwater beneath the site had been impacted by previous agricultural use, with nitrate-N values as high as 30 mg/L and some detections of the herbicide atrazine. Our 12-year study shows that the transition from agricultural to residential land use has changed groundwater quality in both negative and positive ways. Although groundwater elevations showed typical seasonal fluctuations each year, there were no measurable changes in groundwater levels or general flow directions during the 12-year study period. Chloride values increased in many wells, possibly as a result of road salting or water softener discharge. Nitrate concentrations varied spatially and temporally over the study period, with some initial concentrations substantially above the drinking water standard. In some wells, nitrate and atrazine levels have declined substantially since agriculture ceased. However, atrazine was still present at trace concentrations throughout the site in 2014. Wastewater tracers show there are small but detectable impacts from septic effluent on groundwater quality. Particle traces based on a groundwater flow model are consistent with the hypothesis that septic leachate has impacted groundwater quality. © 2018, National Ground Water Association.

Fundamental Importance of Reference Glucose Analyzer Accuracy for Evaluating the Performance of Blood Glucose Monitoring Systems (BGMSs).

PubMed

Bailey, Timothy S; Klaff, Leslie J; Wallace, Jane F; Greene, Carmine; Pardo, Scott; Harrison, Bern; Simmons, David A

2016-07-01

As blood glucose monitoring system (BGMS) accuracy is based on comparison of BGMS and laboratory reference glucose analyzer results, reference instrument accuracy is important to discriminate small differences between BGMS and reference glucose analyzer results. Here, we demonstrate the important role of reference glucose analyzer accuracy in BGMS accuracy evaluations. Two clinical studies assessed the performance of a new BGMS, using different reference instrument procedures. BGMS and YSI analyzer results were compared for fingertip blood that was obtained by untrained subjects' self-testing and study staff testing, respectively. YSI analyzer accuracy was monitored using traceable serum controls. In study 1 (N = 136), 94.1% of BGMS results were within International Organization for Standardization (ISO) 15197:2013 accuracy criteria; YSI analyzer serum control results showed a negative bias (-0.64% to -2.48%) at the first site and a positive bias (3.36% to 6.91%) at the other site. In study 2 (N = 329), 97.8% of BGMS results were within accuracy criteria; serum controls showed minimal bias (<0.92%) at both sites. These findings suggest that the ability to demonstrate that a BGMS meets accuracy guidelines is influenced by reference instrument accuracy. © 2016 Diabetes Technology Society.

Structural phase transition of as-synthesized Sr-Mn nanoferrites by annealing temperature

NASA Astrophysics Data System (ADS)

Amer, M. A.; Meaz, T. M.; Attalah, S. S.; Ghoneim, A. I.

2015-11-01

The Sr0.2Mn0.8Fe2O4 nanoparticle ferrites were synthesized by the co-precipitation method and annealed at different temperatures T. XRD, TEM, FT-IR, VSM and Mössbauer techniques were used to characterize the samples. This study proved that the structural phase of nanoferrites was transformed from cubic spinel for T≤500 °C to Z-type hexagonal for T≥700 °C. The structural transformation was attributed to Jahn-Teller effect of the Mn3+ ions and/or atomic disorder existed in the crystal lattice. The obtained spectra and parameters for the samples were affected by the transformation process. The lattice constant a showed a splitting to a and c for T>500 °C. The lattice constant c, grain and crystallite size R, strain, octahedral B-site band position and force constant, Debye temperature, coercivity Hc, remnant magnetization, squareness and magnetic moment, spontaneous magnetization and hyperfine magnetic fields showed increase against T. The lattice constant a, distortion and dislocation parameters, specific surface area, tetrahedral A-site band position and force constant, threshold frequency, Young's and bulk moduli, saturation magnetization Ms, area ratio of B-/A-sites, A-site line width were decreased with T. Experimental and theoretical densities, porosity, Poison ratio, stiffness constants, rigidity modulus, B-site line width and spontaneous magnetization showed dependence on T, whereas Ms and Hc proved dependence on R.

Assessment of intrinsic bioremediation of jet fuel contamination in a shallow aquifer, Beaufort, South Carolina

USGS Publications Warehouse

Chapelle, Frank; Landmeyer, J.E.; Bradley, P.M.

1995-01-01

Field and laboratory studies show that microorganisms indigenous to the ground-water system underlying Tank Farm C, Marine Corps Air Station Beaufort, S.C., degrade petroleum hydrocarbons under aerobic and anaerobic conditions. Under aerobic conditions, sediments from the shallow aquifer underlying the site mineralized radiolabeled (14C) toluene to 14CO2 with first-order rate constants of about -0.29 per day. Sediments incubated under anaerobic conditions mineralized radiolabeled toluene more slowly, with first-order rate constants of -0.001 per day. Although anaerobic rates of biodegradation are low, they are significant in the hydrologic and geochemical context of the site. Because of low hydraulic conductivities (1.9-9.1 feet per day) and low hydraulic gradients (about 0.004 feet per feet), ground water flows slowly (approximately 20 feet per year) at this site. Furthermore, aquifer sediments contain organic-rich peat that has a high sorptive capacity. Under these conditions, hydrocarbon contaminants have moved no further than 10 feet downgradient of the jet fuel free product. Digital solute-transport simulations, using the range of model parameters measured at the site, show that dissolved contaminants will be completely degraded before they are discharged from the aquifer into adjacent surface-water bodies. These results show that natural attenuation processes are containing the migration of soluble hydrocarbons, and that intrinsic bioremediation is a potentially effective remedial strategy at this site.

Structure-based design of diverse inhibitors of Mycobacterium tuberculosis N-acetylglucosamine-1-phosphate uridyltransferase: combined molecular docking, dynamic simulation, and biological activity.

PubMed

Soni, Vijay; Suryadevara, Priyanka; Sriram, Dharmarajan; Kumar, Santhosh; Nandicoori, Vinay Kumar; Yogeeswari, Perumal

2015-07-01

Persistent nature of Mycobacterium tuberculosis is one of the major factors which make the drug development process monotonous against this organism. The highly lipophilic cell wall, which constituting outer mycolic acid and inner peptidoglycan layers, acts as a barrier for the drugs to enter the bacteria. The rigidity of the cell wall is imparted by the peptidoglycan layer, which is covalently linked to mycolic acid by arabinogalactan. Uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc) serves as the starting material in the biosynthesis of this peptidoglycan layers. This UDP-GlcNAc is synthesized by N-acetylglucosamine-1-phosphate uridyltransferase (GlmU(Mtb)), a bi-functional enzyme with two functional sites, acetyltransferase site and uridyltransferase site. Here, we report design and screening of nine inhibitors against UTP and NAcGlc-1-P of uridyltransferase active site of glmU(Mtb). Compound 4 was showing good inhibition and was selected for further analysis. The isothermal titration calorimetry (ITC) experiments showed the binding energy pattern of compound 4 to the uridyltransferase active site is similar to that of substrate UTP. In silico molecular dynamics (MD) simulation studies, for compound 4, carried out for 10 ns showed the protein-compound complex to be stable throughout the simulation with relative rmsd in acceptable range. Hence, these compounds can serve as a starting point in the drug discovery processes against Mycobacterium tuberculosis.

Structures of minimal catalytic fragments of topoisomerase V reveals conformational changes relevant for DNA binding

PubMed Central

Rajan, Rakhi; Taneja, Bhupesh; Mondragón, Alfonso

2010-01-01

Summary Topoisomerase V is an archaeal type I topoisomerase that is unique among topoisomerases due to presence of both topoisomerase and DNA repair activities in the same protein. It is organized as an N-terminal topoisomerase domain followed by 24 tandem helix hairpin helix (HhH) motifs. Structural studies have shown that the active site is buried by the (HhH) motifs. Here we show that the N-terminal domain can relax DNA in the absence of any HhH motifs and that the HhH motifs are required for stable protein-DNA complex formation. Crystal structures of various topoisomerase V fragments show changes in the relative orientation of the domains mediated by a long bent linker helix, and these movements are essential for the DNA to enter the active site. Phosphate ions bound to the protein near the active site helped model DNA in the topoisomerase domain and shows how topoisomerase V may interact with DNA. PMID:20637419

Probabilistic and Scenario Seismic and Liquefaction Hazard Analysis of the Mississippi Embayment Incorporating Nonlinear Site Effects

NASA Astrophysics Data System (ADS)

Cramer, C. H.; Dhar, M. S.

2017-12-01

The influence of deep sediment deposits of the Mississippi Embayment (ME) on the propagation of seismic waves is poorly understood and remains a major source of uncertainty for site response analysis. Many researchers have studied the effects of these deposits on seismic hazard of the area using available information at the time. In this study, we have used updated and newly available resources for seismic and liquefaction hazard analyses of the ME. We have developed an improved 3D geological model. Additionally, we used surface geological maps from Cupples and Van Arsdale (2013) to prepare liquefaction hazard maps. Both equivalent linear and nonlinear site response codes were used to develop site amplification distributions for use in generating hazard maps. The site amplification distributions are created using the Monte Carlo approach of Cramer et al. (2004, 2006) on a 0.1-degree grid. The 2014 National Seismic Hazard model and attenuation relations (Petersen et al., 2014) are used to prepare seismic hazard maps. Then liquefaction hazard maps are generated using liquefaction probability curves from Holzer (2011) and Cramer et al. (2015). Equivalent linear response (w/ increased precision, restricted nonlinear behavior with depth) shows similar hazard for the ME compared to nonlinear analysis (w/o pore pressure) results. At short periods nonlinear deamplification dominates the hazard, but at long periods resonance amplification dominates. The liquefaction hazard tends to be high in Holocene and late Pleistocene lowland sediments, even with lowered ground water levels, and low in Pleistocene loess of the uplands. Considering pore pressure effects in nonlinear site response analysis at a test site on the lowlands shows amplification of ground motion at short periods. PGA estimates from ME liquefaction and MMI observations are in the 0.25 to 0.4 g range. Our estimated M7.5 PGA hazard within 10 km of the fault can exceed this. Ground motion observations from liquefaction sites in New Zealand and Japan support PGAs below 0.4 g, except at sites within 20 km exhibiting pore-pressure induced acceleration spikes due to cyclic mobility where PGA ranges from 0.5 to 1.5 g. This study is being extended to more detailed seismic and liquefaction hazard studies in five western Tennessee counties under a five year grant from HUD.

Spatiotemporal variation in the postseismic deformation of the 2011 Tohoku-oki earthquake revealed by seafloor geodetic observations

NASA Astrophysics Data System (ADS)

Tomita, F.; Kido, M.; Ohta, Y.; Hino, R.; Iinuma, T.

2016-12-01

Postseismic deformation following the 2011 Tohoku-oki earthquake has been detected by on- and off-shore geodetic observations. GPS/Acoustic (GPS/A) observations [Watanabe et al., 2014, GRL] just above the coseismic primary rupture area (PRA) show significant landward movement in contrast to the trench-ward movement of the on-shore GPS observations, which can be generally explained by viscoelastic relaxation [Sun et al., 2014, Nature]. Furthermore, Tomita et al. [2015, AGU] demonstrated along-trench variation of the postseismic deformation also using GPS/A observations. In this study, we show detailed spatiotemporal characteristics of the postseismic deformation using updated GPS/A measurement results. We employed 20 GPS/A sites located in Tohoku-oki region and had conducted repeated campaign surveys from Sep. 2012 to May 2016. GPS/A positioning was performed using the method of Kido et al. [2006, EPS]. Then, we calculated postseismic displacement rates by applying a weighted robust linear fitting. The updated results of the postseismic displacement rates are consistent with the characteristic revealed by Tomita et al. [2015] but are estimated with better precision ( 2 cm/yr in 1σ). The sites in the north region of PRA show slight trenchward movement (< 5 cm/yr), while the sites in the south region of PRA show significant trenchward movement (5-15 cm/yr) indicating dominance of the afterslip effects. Moreover, the sites above PRA show significant landward movement (10-15 cm/yr) indicating viscoelastic relaxation and interplate relocking effects. Furthermore, the updated results may show temporal decay of afterslip; the temporally decaying displacements have been observed in the south region of PRA. However, such a temporal decay has not been measured in the region where viscoelastic relaxation causes significant deformation. In the presentation, we will discuss detail spatiotemporal evolution of the postseismic deformation processes from the updated results by comparing with other geodetic observations and studies on the postseismic deformation modeling.

Parentage of overlapping offspring of an arboreal-breeding frog with no nest defense: implications for nest site selection and reproductive strategy.

PubMed

Tung, Wan-Ping; Chen, Yi-Huey; Cheng, Wei-Chun; Chuang, Ming-Feng; Hsu, Wan-Tso; Kam, Yeong-Choy; Lehtinen, Richard M

2015-01-01

Overlapping offspring occurs when eggs are laid in a nest containing offspring from earlier reproduction. Earlier studies showed that the parentage is not always obvious due to difficulties in field observation and/or alternative breeding tactics. To unveil the parentage between overlapping offspring and parents is critical in understanding oviposition site selection and the reproductive strategies of parents. Amplectant pairs of an arboreal-breeding frog, Kurixalus eiffingeri, lay eggs in tadpole-occupied nests where offspring of different life stages (embryos and tadpoles) coexist. We used five microsatellite DNA markers to assess the parentage between parents and overlapping offspring. We also tested the hypothesis that the male or female frog would breed in the same breeding site because of the scarcity of nest sites. Results showed varied parentage patterns, which may differ from the phenomenon of overlapping egg clutches reported earlier. Parentage analyses showed that only 58 and 25% of the tadpole-occupied stumps were reused by the same male and female respectively, partially confirming our prediction. Re-nesting by the same individual was more common in males than females, which is most likely related to the cost of tadpole feeding and/or feeding schemes of females. On the other hand, results of parentage analyses showed that about 42 and 75% of male and female respectively bred in tadpole-occupied stumps where tadpoles were genetically unrelated. Results of a nest-choice experiment revealed that 40% of frogs chose tadpole-occupied bamboo cups when we presented identical stumps, without or with tadpoles, suggesting that the habitat saturation hypothesis does not fully explain why frogs used the tadpole-occupied stumps. Several possible benefits of overlapping offspring with different life stages were proposed. Our study highlights the importance of integrating molecular data with field observations to better understand the reproductive biology and nest site selection of anuran amphibians.

Estimating microcystin levels at recreational sites in western Lake Erie and Ohio

USGS Publications Warehouse

Francy, Donna S.; Brady, Amie M. G.; Ecker, Christopher D.; Graham, Jennifer L.; Stelzer, Erin A.; Struffolino, Pamela; Loftin, Keith A.

2016-01-01

Cyanobacterial harmful algal blooms (cyanoHABs) and associated toxins, such as microcystin, are a major global water-quality issue. Water-resource managers need tools to quickly predict when and where toxin-producing cyanoHABs will occur. This could be done by using site-specific models that estimate the potential for elevated toxin concentrations that cause public health concerns. With this study, samples were collected at three Ohio lakes to identify environmental and water-quality factors to develop linear-regression models to estimate microcystin levels. Measures of the algal community (phycocyanin, cyanobacterial biovolume, and cyanobacterial gene concentrations) and pH were most strongly correlated with microcystin concentrations. Cyanobacterial genes were quantified for general cyanobacteria, general Microcystis and Dolichospermum, and for microcystin synthetase (mcyE) for Microcystis, Dolichospermum, and Planktothrix. For phycocyanin, the relations were different between sites and were different between hand-held measurements on-site and nearby continuous monitor measurements for the same site. Continuous measurements of parameters such as phycocyanin, pH, and temperature over multiple days showed the highest correlations to microcystin concentrations. The development of models with high R2values (0.81–0.90), sensitivities (92%), and specificities (100%) for estimating microcystin concentrations above or below the Ohio Recreational Public Health Advisory level of 6 μg L−1 was demonstrated for one site; these statistics may change as more data are collected in subsequent years. This study showed that models could be developed for estimates of exceeding a microcystin threshold concentration at a recreational freshwater lake site, with potential to expand their use to provide relevant public health information to water resource managers and the public for both recreational and drinking waters.

Bone morphogenetic protein 2 activates Smad6 gene transcription through bone-specific transcription factor Runx2.

PubMed

Wang, Qing; Wei, Xiaochao; Zhu, Tianhui; Zhang, Ming; Shen, Run; Xing, Lianping; O'Keefe, Regis J; Chen, Di

2007-04-06

BMP-2 plays an essential role in osteoblast and chondrocyte differentiation, but its signaling mechanism has not been fully defined. In the present studies, we investigated the mechanism through which BMP-2 activates the Smad6 gene. A -2006/+45 Smad6 promoter-luciferase construct was generated along with deletions and Runx2 binding site mutations to examine the role of Smad1 and Runx2 signaling following BMP-2 stimulation in osteoblasts. Transfection of Runx2 or treatment with BMP-2-stimulated promoter activity of the -2006/+45 and -1191/+45 reporters but not the -829/+45 and -374/+45 reporters. No Smad1/5 binding site is present in the -1191/-829 region of the Smad6 promoter. Mutation of the OSE2-a site (-1036/-1031) completely abolished the stimulatory effect of Runx2 as well as BMP-2 on the -2006/+45 and -1191/+45 Smad6 reporters. Gel shift and chromatin immunoprecipitation (ChIP) assays showed that Runx2 binds the OSE2-a element. ChIP assays demonstrated that Smad1 also interacts with the OSE2-a site at the Smad6 promoter through Runx2. The protein degradation of Runx2 is mediated by the E3 ubiquitin ligase Smurf1. In the present studies, we found that Smurf1 binds the OSE2-a site through Runx2 and inhibits Smad6 gene transcription. Treatment with BMP-2 and transfection of Smad1 abolished Smurf1 binding to the OSE2 site. These results show that Smad1 binding excludes Smurf1 interaction with the OSE2 site and promotes Smad6 gene transcription.

Active Site Desolvation and Thermostability Trade-Offs in the Evolution of Catalytically Diverse Triazine Hydrolases.

PubMed

Sugrue, Elena; Carr, Paul D; Scott, Colin; Jackson, Colin J

2016-11-15

The desolvation of ionizable residues in the active sites of enzymes and the subsequent effects on catalysis and thermostability have been studied in model systems, yet little about how enzymes can naturally evolve to include active sites with highly reactive and desolvated charges is known. Variants of triazine hydrolase (TrzN) with significant differences in their active sites have been isolated from different bacterial strains: TrzN from Nocardioides sp. strain MTD22 contains a catalytic glutamate residue (Glu241) that is surrounded by hydrophobic and aromatic second-shell residues (Pro214 and Tyr215), whereas TrzN from Nocardioides sp. strain AN3 has a noncatalytic glutamine residue (Gln241) at an equivalent position, surrounded by hydrophilic residues (Thr214 and His215). To understand how and why these variants have evolved, a series of TrzN mutants were generated and characterized. These results show that desolvation by second-shell residues increases the pK a of Glu241, allowing it to act as a general acid at neutral pH. However, significant thermostability trade-offs are required to incorporate the ionizable Glu241 in the active site and to then enclose it in a hydrophobic microenvironment. Analysis of high-resolution crystal structures shows that there are almost no structural changes to the overall configuration of the active site due to these mutations, suggesting that the changes in activity and thermostability are purely based on the altered electrostatics. The natural evolution of these enzyme isoforms provides a unique system in which to study the fundamental process of charged residue desolvation in enzyme catalysis and its relative contribution to the creation and evolution of an enzyme active site.

Organizational requirements of the SaeR binding sites for a functional P1 promoter of the sae operon in Staphylococcus aureus.

PubMed

Cho, Hoonsik; Jeong, Do-Won; Li, Chunling; Bae, Taeok

2012-06-01

In Staphylococcus aureus, the SaeRS two-component system controls the expression of multiple virulence factors. Of the two promoters in the sae operon, P1 is autoinduced and has two binding sites for the response regulator SaeR. In this study, we examined the organizational requirements of the SaeR binding sites in P1 for transcription activation. Mutational studies showed that both binding sites are essential for binding to phosphorylated SaeR (P-SaeR) and transcription activation. When the 21-bp distance between the centers of the two SaeR binding sites was altered to 26 bp, 31 bp, 36 bp, or 41 bp, only the 31-bp mutant retained approximately 40% of the original promoter activity. When the -1-bp spacing (i.e.,1-bp overlap) between the primary SaeR binding site and the -35 promoter region was altered, all mutant P1 promoters failed to initiate transcription; however, when the first nucleotide of the -35 region was changed from A to T, the mutants with 0-bp or 22-bp spacing showed detectable promoter activity. Although P-SaeR was essential for the binding of RNA polymerase to P1, it was not essential for the binding of the enzyme to the alpha-hemolysin promoter. When the nonoptimal spacing between promoter elements in P1 or the coagulase promoter was altered to the optimal spacing of 17 bp, both promoters failed to initiate transcription. These results suggest that SaeR binding sites are under rather strict organizational restrictions and provide clues for understanding the molecular mechanism of sae-mediated transcription activation.

Magnetic Properties of PMx Collected at Sites with Different Level of Air Pollution

NASA Astrophysics Data System (ADS)

Petrovsky, E.; Kotlik, B.; Kapicka, A.; Zboril, R.

2012-12-01

Magnetic properties of environmental samples can serve as fast and relatively cheap proxy method to investigate occurrence of iron oxides. These methods are very sensitive in detecting strongly magnetic compounds such as magnetite and maghemite and can reveal concentration and assess grain-size distribution of these minerals. This information can be significant in estimating e.g. the source of pollutants, monitoring pollution load, or investigating seasonal and climatic effects. We studied magnetic properties of PM1, PM2.5 and PM10 and total suspended matter (TSP), collected over 12-48 hours at sites with different level of air pollution: a small clean settlement in south Bohemia, industrial site close to steel works, industrial site close to open mine pit, urban and traffic site. In our contribution we will show typical differences in PMx properties. SEM observations will be complemented by magnetic measurements and Mossbauer spectroscopy. In all the ssampled sites, the SEM images clearly reveal spherules rich in iron oxides. Thermomagentic measurements (temperature dependence of magnetic susceptibility) prove that magnetite is the dominant magnetic phase in atmospheric dust in samples from all sites. Hysteresis loops and IRM acquisition curve could be reliably measured. Surprisingly, finer dust particles show smaller coercive force than the coarser ones. Mossbauer spectroscopy could be interpreted in terms of multi-domain magnetite only in the samples with PMx dominated by the steel works, where the content of magnetite was the highest. The results demonstrate that magnetic measurements are extremely sensitive to trace amount of ferrimagnetic iron oxides, which were in many cases below the sensitivity limit of Mossbauer spectroscopy. This study is supported by the Czech Science Foundation through grant #P210/10/0554.

pH as a Driver for Ammonia-Oxidizing Archaea in Forest Soils.

PubMed

Stempfhuber, Barbara; Engel, Marion; Fischer, Doreen; Neskovic-Prit, Ganna; Wubet, Tesfaye; Schöning, Ingo; Gubry-Rangin, Cécile; Kublik, Susanne; Schloter-Hai, Brigitte; Rattei, Thomas; Welzl, Gerhard; Nicol, Graeme W; Schrumpf, Marion; Buscot, Francois; Prosser, James I; Schloter, Michael

2015-05-01

In this study, we investigated the impact of soil pH on the diversity and abundance of archaeal ammonia oxidizers in 27 different forest soils across Germany. DNA was extracted from topsoil samples, the amoA gene, encoding ammonia monooxygenase, was amplified; and the amplicons were sequenced using a 454-based pyrosequencing approach. As expected, the ratio of archaeal (AOA) to bacterial (AOB) ammonia oxidizers' amoA genes increased sharply with decreasing soil pH. The diversity of AOA differed significantly between sites with ultra-acidic soil pH (<3.5) and sites with higher pH values. The major OTUs from soil samples with low pH could be detected at each site with a soil pH <3.5 but not at sites with pH >4.5, regardless of geographic position and vegetation. These OTUs could be related to the Nitrosotalea group 1.1 and the Nitrososphaera subcluster 7.2, respectively, and showed significant similarities to OTUs described from other acidic environments. Conversely, none of the major OTUs typical of sites with a soil pH >4.6 could be found in the ultra- and extreme acidic soils. Based on a comparison with the amoA gene sequence data from a previous study performed on agricultural soils, we could clearly show that the development of AOA communities in soils with ultra-acidic pH (<3.5) is mainly triggered by soil pH and is not influenced significantly by the type of land use, the soil type, or the geographic position of the site, which was observed for sites with acido-neutral soil pH.

Methane hydrate formation in turbidite sediments of northern Cascadia, IODP Expedition 311

USGS Publications Warehouse

Torres, M.E.; Trehu, A.M.; Cespedes, N.; Kastner, M.; Wortmann, U.G.; Kim, J.-H.; Long, P.; Malinverno, A.; Pohlman, J.W.; Riedel, M.; Collett, T.

2008-01-01

Expedition 311 of the Integrated Ocean Drilling Program (IODP) to northern Cascadia recovered gas-hydrate bearing sediments along a SW-NE transect from the first ridge of the accretionary margin to the eastward limit of gas-hydrate stability. In this study we contrast the gas gas-hydrate distribution from two sites drilled ~ 8??km apart in different tectonic settings. At Site U1325, drilled on a depositional basin with nearly horizontal sedimentary sequences, the gas-hydrate distribution shows a trend of increasing saturation toward the base of gas-hydrate stability, consistent with several model simulations in the literature. Site U1326 was drilled on an uplifted ridge characterized by faulting, which has likely experienced some mass wasting events. Here the gas hydrate does not show a clear depth-distribution trend, the highest gas-hydrate saturation occurs well within the gas-hydrate stability zone at the shallow depth of ~ 49??mbsf. Sediments at both sites are characterized by abundant coarse-grained (sand) layers up to 23??cm in thickness, and are interspaced within fine-grained (clay and silty clay) detrital sediments. The gas-hydrate distribution is punctuated by localized depth intervals of high gas-hydrate saturation, which preferentially occur in the coarse-grained horizons and occupy up to 60% of the pore space at Site U1325 and > 80% at Site U1326. Detailed analyses of contiguous samples of different lithologies show that when enough methane is present, about 90% of the variance in gas-hydrate saturation can be explained by the sand (> 63????m) content of the sediments. The variability in gas-hydrate occupancy of sandy horizons at Site U1326 reflects an insufficient methane supply to the sediment section between 190 and 245??mbsf. ?? 2008 Elsevier B.V.

Population dose commitments due to radioactive releases from Nuclear-Power-Plant Sites in 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.; Peloquin, R.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1979. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each site. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each site is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving variousmore » average dose commitments from the airborne pathways. The total dose commitment from both liquid and airborne pathways ranged from a high of 1300 person-rem to a low of 0.0002 person-rem with an arithmetic mean of 38 person-rem. The total population dose for all sites was estimated at 1800 person-rem for the 94 million people considered at risk. The average individual dose commitment from all pathways on a site basis ranged from a low of 2 x 10/sup -6/ mrem to a high of 0.7 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites.« less

Population Dose Commitments Due to Radioactive Releases from Nuclear Power Plant Sites in 1977

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D. A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1977. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each site. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ, Also included for each site is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving variousmore » average dose commitments from the airborne pathways. The total dose commitment from both liquid and airborne pathways ranged from a high of 220 person-rem to a low of 0.003 person-rem with an arithmetic mean of 16 person-rem. The total population dose for all sites was estimated at 700 person-rem for the 92 million people considered at risk. The average individual dose commitment from all pathways on a site basis ranged from a low of 2 x 10{sup -5} mrem to a high of 0.1 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites.« less

Land planarian assemblages in protected areas of the interior atlantic forest: implications for conservation.

PubMed

Negrete, Lisandro; Colpo, Karine D; Brusa, Francisco

2014-01-01

Land planarians are an interesting group of free-living flatworms that can be useful as bioindicators because of their high sensitivity to environmental changes and low dispersal capacity. In this study, we describe and compare assemblages of land planarians from areas with different conservation degrees of the Interior Atlantic Forest (Misiones, Argentina), and assess factors that could be related to their abundance and richness. Eight sites were tracked in search of land planarians in Reserva de Vida Silvestre Urugua-í (RVSU) and Campo Anexo Manuel Belgrano (CAMB). Diurnal and nocturnal surveys were performed in each site along nine sampling campaigns. We collected 237 individuals belonging to 18 species of the subfamily Geoplaninae. All sites were dominated by Geoplana sp. 1 and Pasipha hauseri. The richness estimators showed that there would be more species in RVSU than in CAMB. The abundance and richness of land planarians was high during the night and after rainfalls, suggesting an increased activity of flatworms under such conditions. The abundance and richness of land planarians were also related to the conservation condition of the sites. Disturbed sites showed less abundance and richness, and were segregated from non-disturbed ones by nmMDS analysis. Beta diversity between sites was higher than expected, indicating that the species turnover between sites contributed more to the total richness (gamma diversity) than the alpha diversity.

Two-Site Comparison of Transpiration by Larrea Tridentata

NASA Astrophysics Data System (ADS)

Cavanaugh, M. L.; Kurc, S. A.; Scott, R. L.; Bryant, R. B.

2008-12-01

As a result of landscape changes within the desert southwestern U.S. such as increased grazing, reduced wildfire frequency, and changes in atmospheric conditions, the native creosotebush (Larrea tridentata) has encroached upon historically grass-dominated ecosystems, expanding in range and land cover density. To understand how creosotebush influences the water budget of ecosystems, heat balance sap flow sensors were employed on creosotebush stems at both the Santa Rita Experimental Range (SRER) and Walnut Gulch Experimental Watershed (WGEW). Additionally, both sites are equipped with eddy covariance towers, associated micrometeorological measurements, and profiles of water content reflectometers for soil moisture. The differences found between the two sites, including soil type and precipitation regime, are the basis of the following hypotheses. Firstly, we hypothesize that we will not see transpiration (T) responses following storms less than 5 mm at both sites. Secondly, we hypothesize that at both sites we will see a lagged response of T to large precipitation events, with evaporation being the dominate component in the partitioning of evapotranspiration (ET) for the first two days. Thirdly, we hypothesize that the ratio of plant transpiration to total evapotranspiration (T/ET) will be less at SRER due to the larger amount of bare soil exposed at this site. In this study, we show data from one summer at both sites and show how these relate to different precipitation events and soil moisture reservoirs.

Decoherence in models for hard-core bosons coupled to optical phonons

NASA Astrophysics Data System (ADS)

Dey, A.; Lone, M. Q.; Yarlagadda, S.

2015-09-01

Understanding coherent dynamics of excitons, spins, or hard-core bosons (HCBs) has tremendous scientific and technological implications for quantum computation. Here, we study decay of excited-state population and decoherence in two models for HCBs, namely, a two-site HCB model with site-dependent strong potentials and subject to non-Markovian dynamics and an infinite-range HCB model governed by Markovian dynamics. Both models are investigated in the regimes of antiadiabaticity and strong HCB-phonon coupling with each site providing a different local optical phonon environment; furthermore, the HCB systems in both models are taken to be initially uncorrelated with the environment in the polaronic frame of reference. In the case of the two-site HCB model, we show clearly that the degree of decoherence and decay of excited state are enhanced by the proximity of the site-energy difference to the eigenenergy of phonons and are most pronounced when the site-energy difference is at resonance with twice the polaronic energy; additionally, the decoherence and the decay effects are reduced when the strength of HCB-phonon coupling is increased. For the infinite-range model, when the site energies are the same, we derive an effective many-body Hamiltonian that commutes with the long-range system Hamiltonian and thus has the same set of eigenstates; consequently, a quantum-master-equation approach shows that the quantum states of the system do not decohere.

Water and vapor transfer in vadose zone of Gobi desert and riparian in the hyper arid environment of Ejina, China

NASA Astrophysics Data System (ADS)

Du, C.; Yu, J.; Sun, F.; Liu, X.

2015-12-01

To reveal how water and vapor transfer in vadose zone affect evapotranspiration in Gobi desert and riparian in hyper arid region is important for understanding eco-hydrological process. Field studies and numerical simulations were imported to evaluate the water and vapor movement processes under non isothermal and lower water content conditions. The soil profiles (12 layers) in Gobi desert and riparian sites of Ejina were installed with sensors to monitor soil moisture and temperature for 1 year. The meteorological conditions and water table were measured by micro weather stations and mini-Divers respectively in the two sites. Soil properties, including particles composition, moisture, bulk density, water retention curve, and saturated hydraulic conductivity of two site soil profiles, was measured. The observations showed that soil temperatures for the two sites displayed large diurnal and seasonal fluctuations. Temperature gradients with depth resulted in a downward in summer and upward in winter and became driving force for thermal vapor movement. Soil moistures in Gobi desert site were very low and varied slowly with time. While the soil moistures in riparian site were complicated due to root distribution but water potentials remained uniform with time. The hydrus-1D was employed to simulate evapotranspiration processes. The simulation results showed the significant difference of evaporation rate in the Gobi desert and riparian sites.

Local electronic and optical behaviors of a-plane GaN grown via epitaxial lateral overgrowth

NASA Astrophysics Data System (ADS)

Moore, J. C.; Kasliwal, V.; Baski, A. A.; Ni, X.; Özgür, Ü.; Morkoç, H.

2007-01-01

Conductive atomic force microscopy and near-field optical microscopy (NSOM) were used to study the morphology, conduction, and optical properties of a-plane GaN films grown via epitaxial lateral overgrowth (ELO) by metal organic chemical vapor deposition. The AFM images for the coalesced ELO films show undulations, where the window regions appear as depressions with a high density of surface pits. At reverse bias below 12V, very low uniform conduction (2pA) is seen in the window regions. Above 20V, a lower-quality sample shows localized sites inside the window regions with significant leakage, indicating a correlation between the presence of surface pits and leakage sites. Room temperature NSOM studies explicitly showed enhanced optical quality in the wing regions of the overgrown GaN due to a reduced density of dislocations, with the wings and the windows clearly discernible from near-field photoluminescence mapping.

Is hyporheic flow an indicator for salmonid spawning site selection?

NASA Astrophysics Data System (ADS)

Benjankar, R. M.; Tonina, D.; Marzadri, A.; McKean, J. A.; Isaak, D.

2015-12-01

Several studies have investigated the role of hydraulic variables in the selection of spawning sites by salmonids. Some recent studies suggest that the intensity of the ambient hyporheic flow, that present without a salmon egg pocket, is a cue for spawning site selection, but others have argued against it. We tested this hypothesis by using a unique dataset of field surveyed spawning site locations and an unprecedented meter-scale resolution bathymetry of a 13.5 km long reach of Bear Valley Creek (Idaho, USA), an important Chinook salmon spawning stream. We used a two-dimensional surface water model to quantify stream hydraulics and a three-dimensional hyporheic model to quantify the hyporheic flows. Our results show that the intensity of ambient hyporheic flows is not a statistically significant variable for spawning site selection. Conversely, the intensity of the water surface curvature and the habitat quality, quantified as a function of stream hydraulics and morphology, are the most important variables for salmonid spawning site selection. KEY WORDS: Salmonid spawning habitat, pool-riffle system, habitat quality, surface water curvature, hyporheic flow

Bulk deposition of organic and inorganic nitrogen in southwest China from 2008 to 2013.

PubMed

Song, Ling; Kuang, Fuhong; Skiba, Ute; Zhu, Bo; Liu, Xuejun; Levy, Peter; Dore, Anthony; Fowler, David

2017-08-01

China is regarded as one of the nitrogen deposition hotspots in the world. Measurements to-date have focused mainly on the North China Plain, ignoring the fact that atmospheric chemical and physical properties vary across the country and that there may be other hotspots regions that should be investigated. For this reason we have conducted a six year study, measuring the bulk deposition of reduced (NH 4 -N), oxidized (NO 3 -N), and dissolved organic nitrogen (DON) at three contrasting sites in the Sichuan province, southwest China. The study sites were a high altitude forest in the Gongga Mountains (GG), an agriculture dominated region in Yanting (YT) and an urban site in the mega city Chengdu (CD). The annual average bulk deposition fluxes of total dissolved nitrogen (TDN) were 7.4, 23.1 and 36.6 kg N ha -1 yr -1 at GG, YT and CD sites, respectively, during the study period 2008 to 2013. The contributions of NH 4 -N, NO 3 -N and DON to the TDN were in the range of 48.4-57.8%, 28.8-43.7%, and 8.0-15.6%, respectively. DON bulk deposition was mainly dominated by agricultural activities. TDN bulk deposition fluxes showed increasing trends at the agricultural and urban sites from 2008 to 2013, but there was little change at the remote forest (GG) site. While reduced N dominated bulk N deposition at all the three sites, its contribution showed a decreasing trend, suggesting a gradual increase in the importance of oxidized N. These results reveal the value of long term monitoring in detecting changes in the atmospheric chemical composition of this rapidly changing region, and their inclusion in the policy debate regarding which sources should be controlled in order to reduce the long term impacts of N deposition, especially for southwest China, where there are few measurements of N deposition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Eco-bio-social research on dengue in Asia: a multicountry study on ecosystem and community-based approaches for the control of dengue vectors in urban and peri-urban Asia.

PubMed

Sommerfeld, Johannes; Kroeger, Axel

2012-12-01

This article provides an overview of methods and cross-site insights of a 5-year research and capacity building initiative conducted between 2006 and 2011 in six countries of South Asia (India, Sri Lanka) and South-East Asia (Indonesia, Myanmar, Philippines, Thailand).The initiative managed an interdisciplinary investigation of ecological, biological, and social (i.e., eco-bio-social) dimensions of dengue in urban and peri-urban areas, and developed community-based interventions aimed at reducing dengue vector breeding and viral transmission. The multicountry study comprised interdisciplinary research groups from six leading Asian research institutions. The groups conducted a detailed situation analysis to identify and characterize local eco-bio-social conditions, and formed a community-of-practice for EcoHealth research where group partners disseminated results and collaboratively developed site-specific intervention tools for vector-borne diseases. In sites where water containers produced more than 70% of Aedes pupae, interventions ranged from mechanical lid covers for containers to biological control. Where small discarded containers presented the main problem, groups experimented with solid waste management, composting and recycling schemes. Many intervention tools were locally produced and all tools were implemented through community partnership strategies. All sites developed socially and culturally appropriate health education materials. The study also mobilised and empowered women's, students' and community groups and at several sites organized new volunteer groups for environmental health. The initiative's programmes showed significant impact on vector densities in some sites. Other sites showed varying effect - partially attributable to the 'contamination' of control groups - yet led to significant outcomes at the community level where local groups united around broad interests in environmental hygiene and sanitation. The programme's findings are relevant for defining efficient, effective and ecologically sound vector control interventions based on local evidence and in accordance with WHO's strategy for integrated vector management.

Eco-bio-social research on dengue in Asia: a multicountry study on ecosystem and community-based approaches for the control of dengue vectors in urban and peri-urban Asia

PubMed Central

Sommerfeld, Johannes; Kroeger, Axel

2012-01-01

This article provides an overview of methods and cross-site insights of a 5-year research and capacity building initiative conducted between 2006 and 2011 in six countries of South Asia (India, Sri Lanka) and South-East Asia (Indonesia, Myanmar, Philippines, Thailand).The initiative managed an interdisciplinary investigation of ecological, biological, and social (i.e., eco-bio-social) dimensions of dengue in urban and peri-urban areas, and developed community-based interventions aimed at reducing dengue vector breeding and viral transmission. The multicountry study comprised interdisciplinary research groups from six leading Asian research institutions. The groups conducted a detailed situation analysis to identify and characterize local eco-bio-social conditions, and formed a community-of-practice for EcoHealth research where group partners disseminated results and collaboratively developed site-specific intervention tools for vector-borne diseases. In sites where water containers produced more than 70% of Aedes pupae, interventions ranged from mechanical lid covers for containers to biological control. Where small discarded containers presented the main problem, groups experimented with solid waste management, composting and recycling schemes. Many intervention tools were locally produced and all tools were implemented through community partnership strategies. All sites developed socially and culturally appropriate health education materials. The study also mobilised and empowered women’s, students’ and community groups and at several sites organized new volunteer groups for environmental health. The initiative’s programmes showed significant impact on vector densities in some sites. Other sites showed varying effect — partially attributable to the ‘contamination’ of control groups — yet led to significant outcomes at the community level where local groups united around broad interests in environmental hygiene and sanitation. The programme’s findings are relevant for defining efficient, effective and ecologically sound vector control interventions based on local evidence and in accordance with WHO’s strategy for integrated vector management. PMID:23318234

In vitro and in vivo corrosion evaluation of nickel-chromium- and copper-aluminum-based alloys.

PubMed

Benatti, O F; Miranda, W G; Muench, A

2000-09-01

The low resistance to corrosion is the major problem related to the use of copper-aluminum alloys. This in vitro and in vivo study evaluated the corrosion of 2 copper-aluminum alloys (Cu-Al and Cu-Al-Zn) compared with a nickel-chromium alloy. For the in vitro test, specimens were immersed in the following 3 corrosion solutions: artificial saliva, 0.9% sodium chloride, and 1.0% sodium sulfide. For the in vivo test, specimens were embedded in complete dentures, so that one surface was left exposed. The 3 testing sites were (1) close to the oral mucosa (partial self-cleaning site), (2) surface exposed to the oral cavity (self-cleaning site), and (3) specimen bottom surface exposed to the saliva by means of a tunnel-shaped perforation (non-self-cleaning site). Almost no corrosion occurred with the nickel-chromium alloy, for either the in vitro or in vivo test. On the other hand, the 2 copper-aluminum-based alloys exhibited high corrosion in the sulfide solution. These same alloys also underwent high corrosion in non-self-cleaning sites for the in vivo test, although minimal attack was observed in self-cleaning sites. The nickel-chromium alloy presented high resistance to corrosion. Both copper-aluminum alloys showed considerable corrosion in the sulfide solution and clinically in the non-self-cleaning site. However, in self-cleaning sites these 2 alloys did not show substantial corrosion.

Survival and enumeration of the fecal indicators Bifidobacterium adolescentis and Escherichia coli in a tropical rain forest watershed.

PubMed Central

Carrillo, M; Estrada, E; Hazen, T C

1985-01-01

The density of Bifidobacterium spp., fecal coliforms, Escherichia coli, and total anaerobic bacteria, acridine orange direct counts, percentages of total bacterial community activity and respiration, and 12 physical and chemical parameters were measured simultaneously at six sites for 12 months in the Mameyes River rain forest watershed, Puerto Rico. The densities of all bacteria were higher than those reported for uncontaminated temperate rivers, even though other water quality parameters would indicate that all uncontaminated sites were oligotrophic. The highest densities for all indicator bacteria were at the site receiving sewage effluent; however, the highest elevation site in the watershed had the next highest densities. Correlations between bacterial densities, nitrates, temperature, phosphates, and total phosphorus indicated that all viable counts were related to nutrient levels, regardless of the site sampled. In situ diffusion chamber studies at two different sites indicated that E. coli could survive, remain physiologically active, and regrow at rates that were dependent on nutrient levels of the ambient waters. Bifidobacterium adolescentis did not survive at either site but did show different rates of decline and physiological activity at the two sites. Bifidobacteria show promise as a better indicator of recent fecal contamination in tropical freshwaters than E. coli or fecal coliforms; however, the YN-6 medium did not prove to be effective for enumeration of bifidobacteria. The coliform maximum contaminant levels for assessing water usability for drinking and recreation appear to be unworkable in tropical freshwaters. PMID:3901921

Characterization and analysis of temporal and spatial variations in habitat and macroinvertebrate community structure, Fountain Creek basin, Colorado Springs and vicinity, Colorado, 1998-2001

USGS Publications Warehouse

Bruce, James F.

2002-01-01

The Fountain Creek Basin in and around Colorado Springs, Colorado, is affected by various land- and water-use activities. Biological, hydrological, water-quality, and land-use data were collected at 10 sites in the Fountain Creek Basin from April 1998 through April 2001 to provide a baseline characterization of macroinvertebrate communities and habitat conditions for comparison in subsequent studies; and to assess variation in macroinvertebrate community structure relative to habitat quality. Analysis of variance results indicated that instream and riparian variables were not affected by season, but significant differences were found among sites. Nine metrics were used to describe and evaluate macroinvertebrate community structure. Statistical analysis indicated that for six of the nine metrics, significant variability occurred between spring and fall seasons for 60 percent of the sites. Cluster analysis (unweighted pair group method average) using macroinvertebrate presence-absence data showed a well-defined separation between spring and fall samples. Six of the nine metrics had significant spatial variation. Cluster analysis using Sorenson?s Coefficient of Community values computed from macroinvertebrate density (number of organisms per square meter) data showed that macroinvertebrate community structure was more similar among tributary sites than main-stem sites. Canonical correspondence analysis identified a substrate particle-size gradient from site-specific species-abundance data and environmental correlates that decreased the 10 sites to 5 site clusters and their associated taxa.

Erosion and vegetation restoration impacts on ecosystem carbon dynamics in South China

USGS Publications Warehouse

Tang, X.; Liu, Shuguang; Zhou, G.

2010-01-01

To quantify the consequences of erosion and vegetation restoration on ecosystem C dynamics (a key element in understanding the terrestrial C cycle), field measurements were collected since 1959 at two experimental sites set up on highly disturbed barren land in South China. One site had received vegetation restoration (the restored site) while the other received no planting and remained barren (the barren site). The Erosion-Deposition Carbon Model (EDCM) was used to simulate the ecosystem C dynamics at both sites. The on-site observations in 2007 showed that soil organic C (SOC) storage in the top 80-cm soil layer at the barren site was 50.3 ± 3.5 Mg C ha−1, half that of the restored site. The SOC and surface soil loss by erosion at the restored site from 1959 to 2007 was 3.7 Mg C ha−1 and 2.2 cm, respectively—one-third and one-eighth that of the barren site. The on-site C sequestration in SOC and vegetation at the restored site was 0.67 and 2.5 Mg C ha−1 yr−1, respectively, from 1959 to 2007, driven largely by tree growth and high atmospheric N deposition in the study area. Simulated findings suggested that higher N deposition resulted in higher on-site SOC storage in the soil profile (with SOC in the top 20-cm layer increasing more significantly), and higher on-site ecosystem C sequestration as long as N saturation was not reached. Lacking human-induced vegetation recovery, the barren site remained as barren land from 1959 to 2007 and the on-site C decrease was 0.28 Mg C ha−1 yr−1 Our study clearly indicated that vegetation restoration and burial by soil erosion provide a large potential C sink in terrestrial ecosystems.

Multiple pathways from three types of sugar receptor sites to metabotropic transduction pathways of the blowfly: study by the whole cell-clamp experiments.

PubMed

Kan, Hideko; Kataoka-Shirasugi, Naoko; Amakawa, Taisaku

2011-09-01

Multiple pathways from three types of multiple receptor sites to three types of metabotropic signal transduction pathways were investigated in the whole cell-clamp experiments using isolated labellar sugar receptor neurons (cells) of the adult blowfly, Phormia regina. First, the concentration-response curves of three types of sweet taste components specialized to multiple receptor sites were obtained: sucrose for the pyranose sites (P-sites), fructose for the furanose sites (F-sites), and l-valine for the alkyl sites (R-sites). Next, the effects of inhibitors such as 2', 5'-dideoxyadenosine on adenylyl cyclase in the cAMP pathway, LY 83583 on guanylyl cyclase in the cGMP pathway, and U-73122 on phospholipase C in the IP₃ pathway were examined. The results showed that all of the inhibitors affected each specific target in the second-messenger transduction pathways. The obtained results verified that the P-site corresponded to the cAMP, the F-site to the cGMP, and the R-site to the IP₃ transduction pathway, and that these three signal pathways did not have crossing points. Copyright © 2011 Elsevier Inc. All rights reserved.

Streamflow, suspended-sediment, and soil-erosion data from Kaulana and Hakioawa watersheds, Kaho'olawe, Hawai'i,

USGS Publications Warehouse

Izuka, Scot K.; Abbott, Lyman L.

2010-01-01

Various events over the last two centuries have destroyed the vegetation and caused rapid soil erosion on large areas of the small, arid, windy tropical shield-volcano island of Kaho`olawe, Hawai`i. These activities were largely halted in the 1990s, and efforts have been made to restore the island's vegetation in order to stem erosion. In 2003, the Kaho`olawe Island Reserve Commission (KIRC) began restoration efforts using native vegetation. In 2006 to 2010, the U.S. Geological Survey (USGS), in cooperation with the KIRC, monitored streamflow, fluvial suspended-sediment transport, and erosion rates in the Hakioawa and Kaulana watersheds on northeastern Kaho`olawe to provide information needed to assess the effectiveness of restoration efforts. This report presents the results from this monitoring. Results.-Hakioawa and Kaulana gulches were dry about 90 percent of the time during the monitoring period; mean annual flow was 0.06 ft3/s at Hakioawa Gulch gage and 0.01 ft3/s at the Kaulana Gulch gage. For the period when the sediment gages on both gulches were operating concurrently (October 2007 to September 2009), sediment discharge was higher from Hakioawa Gulch than from Kaulana Gulch. The annual suspended-sediment loads for the concurrent period averaged 1,880 tons at the Hakioawa Gulch gage and 276 tons at the Kaulana Gulch gage. Of the 77 erosion-monitoring sites in the Hakioawa and Kaulana watersheds, 50 had overall rates of change indicating erosion for the monitoring period, ranging from -1 to -10 mm/yr and averaging -3 mm/yr. Seven sites had rates of change indicating overall deposition, ranging from 1 to 15 mm/yr and averaging 5 mm/yr. Twenty had rates of change below detection (less than ?1 mm/yr). The average rate of change for the 26 sites in areas that have undergone restoration by the KIRC was below the detection limit of the erosion-monitoring method. In comparison, the 51 sites in nonrestoration areas averaged -2 mm/y. Both of these averages, however, include sites that showed overall erosion as well as sites that showed overall deposition. The average rate of change was -1 mm/yr for both the 32 sites on rills and the 42 sites on interfluves; both categories include sites that showed deposition as well as sites that showed erosion. All three sites on hummocks showed overall erosion, with an average rate of -8 mm/yr. Both the Hakioawa and Kaulana watersheds showed an average rate of change of -1 mm/yr, and both included sites that showed erosion and sites that showed deposition. For sites with negative rates of change indicating erosion, the average rate of change during the monitoring period was -2 mm/yr in restoration areas and -3 mm/yr in nonrestoration areas. For sites with positive rates of change indicating deposition, the average rate of change was 5 mm/yr in restoration areas and 6 mm/yr in nonrestoration sites. The average rate of change for rills was 1 mm/yr in restoration areas and -2 mm/yr in nonrestoration sites. The average rate of change for interfluves was below detection in restoration areas and -1 mm/yr in nonrestoration areas. Potential Use and Limitation of Data.-Additional statistical comparisons of various subsets of erosion data can be used to assess the effectiveness of restoration efforts or how existing landforms, vegetation, climate, and other physical basin characteristics affect erosion and fluvial sediment transport in the watersheds. Further investigation to identify what factors cause the Kaulana watershed to have much lower runoff and sediment loads than the Hakioawa watershed may yield valuable information for developing and modifying restoration strategies. Continued monitoring of streamflow, sediment transport, and erosion is key to assessing the long-term effectiveness of restoration and can provide insight to the island's recovery since the eradication of feral goats and cessation of use as a military bombing range; the results of this study provide the

ROCK AND SOIL PHYSICAL PROPERTIES AT THE MER GUSEV CRATER AND MERIDIANI PLANUM LANDING SITES

NASA Technical Reports Server (NTRS)

Ming, Douglas W.; Richter, L.; Arvidson, R.; Bell, J.; Cabrol, N.; Gorevan, S.; Greeley, R.; Herkenhoff, K.

2006-01-01

Following the successful landings of both Mars Exploration Rover (MER) vehicles at Gusev Crater and Meridiani Planum, respectively, their Athena suite of instruments is being used to study the geologic history of these two very different landing sites on Mars that had been selected on the basis of showing different types of evidence for aqueous processes in the planet s past. Utilizing the on-board instruments as well as the rovers mobility system, a wide range of physical properties investigations is carried out as well - the subject of this abstract - that provide additional information on the geology and processes at the sites. Results of the mission in general as well as of the physical properties studies thus far greatly exceed expectations in that observations and measurements by both vehicles show a rich variety in materials and processes: the Gusev site in the vicinity of the lander is remarkably flat and generally devoid of large rocks along traverses up to the time of this writing (approx.Sol 50) and suggestive of a deflated surface with generally only thin veneers of bright dust while exhibiting evidence of a widespread occurrence of a crust from cemented fines that has been observed to fail in the form of blocky clods when disturbed by vehicle rolling action; numerous small and shallow depressions - presumably created by impacts - are observed at the site which are infilled with bright, fine-grained material that likewise appears indurated and which was studied by a trenching experiment; small ripple bedforms are scattered across the site and were characterized in terms of particle size distributions. At the Meridiani site, studies so far - up to approx.Sol 33 - have focussed on soils and the rock outcrop encountered within the approx.20 m diameter crater that the spacecraft came to rest in: from a physical properties point of view, a mantle of dark, well-sorted, apparently basaltic sand with small to moderate cohesion has been of interest - and has been studied by a trenching experiment - as well as a fine-grained unit underlying the mantle at least locally within the crater. Rock grindings were accomplished successfully at both sites at the time of this writing, suggesting different strengths of the two targets (the basaltic rock nicknamed Adirondack at Gusev and the Meridiani rock outcrop) in addition to enabling compositional measurements below the original rock surfaces.

Suicide by Jumping and Accessibility of Bridges: Results from a National Survey in Switzerland

ERIC Educational Resources Information Center

Reisch, Thomas; Schuster, Ursula; Michel, Konrad

2007-01-01

Rates of suicide by jumping show large regional differences. Barriers on bridges may prevent suicides but also may lead to a substitution of jumping site or method. The aim of our study was to compare suicide data from regions with and without suicide bridges and to estimate the effects on method and site substitution if bridges were to be…

How Users Take Advantage of Different Forms of Interactivity on Online News Sites: Clicking, E-Mailing, and Commenting

ERIC Educational Resources Information Center

Boczkowski, Pablo J.; Mitchelstein, Eugenia

2012-01-01

This study examines the uptake of multiple interactive features on news sites. It looks at the thematic composition of the most clicked, most e-mailed, and most commented stories during periods of heightened and routine political activity. Results show that (a) during the former period, the most commented stories were more likely to be focused on…

Synthesis and Properties of Homonuclear, Dimetallic Nickel(II), Copper(II) and Zinc(II) Complexes of p-Xylenediyl and 2-Butynediyl-Bridged Dicyclens

DTIC Science & Technology

1993-05-01

urease which contains two nickel ions in the active site. Catalytic hydrolysis studies are in progress. 20 DISTRIBUTION /AVAILABILITY OF ABSTRACT 21...for hydrolytic metalloenzymes. In contrast, the enzyme urease has becti show’n tU coftifl two nickel(II) ions in the active site," but as yet the

Reconstructing the Qo Site of Plasmodium falciparum bc 1 Complex in the Yeast Enzyme

PubMed Central

Vallières, Cindy; Fisher, Nicholas; Meunier, Brigitte

2013-01-01

The bc 1 complex of the mitochondrial respiratory chain is essential for Plasmodium falciparum proliferation, the causative agent of human malaria. Therefore, this enzyme is an attractive target for antimalarials. However, biochemical investigations of the parasite enzyme needed for the study of new drugs are challenging. In order to facilitate the study of new compounds targeting the enzyme, we are modifying the inhibitor binding sites of the yeast Saccharomyces cerevisiae to generate a complex that mimics the P. falciparum enzyme. In this study we focused on its Qo pocket, the site of atovaquone binding which is a leading antimalarial drug used in treatment and causal prophylaxis. We constructed and studied a series of mutants with modified Qo sites where yeast residues have been replaced by P. falciparum equivalents, or, for comparison, by human equivalents. Mitochondria were prepared from the yeast Plasmodium-like and human-like Qo mutants. We measured the bc 1 complex sensitivity to atovaquone, azoxystrobin, a Qo site targeting fungicide active against P. falciparum and RCQ06, a quinolone-derivative inhibitor of P. falciparum bc 1 complex.The data obtained highlighted variations in the Qo site that could explain the differences in inhibitor sensitivity between yeast, plasmodial and human enzymes. We showed that the yeast Plasmodium-like Qo mutants could be useful and easy-to-use tools for the study of that class of antimalarials. PMID:23951230

Multidisciplinary approaches to managing osteoarthritis in multiple joint sites: a systematic review.

PubMed

Finney, Andrew; Healey, Emma; Jordan, Joanne L; Ryan, Sarah; Dziedzic, Krysia S

2016-07-08

The National Institute for Health and Care Excellence's Osteoarthritis (OA) guidelines recommended that future research should consider the benefits of combination therapies in people with OA across multiple joint sites. However, the clinical effectiveness of such approaches to OA management is unknown. This systematic review therefore aimed to identify the clinical and cost effectiveness of multidisciplinary approaches targeting multiple joint sites for OA in primary care. A systematic review of randomised controlled trials. Computerised bibliographic databases were searched (MEDLINE, EMBASE, CINAHL, PsychINFO, BNI, HBE, HMIC, AMED, Web of Science and Cochrane). Studies were included if they met the following criteria; a randomised controlled trial (RCT), a primary care population with OA across at least two different peripheral joint sites (multiple joint sites), and interventions undertaken by at least two different health disciplines (multidisciplinary). The Cochrane 'Risk of Bias' tool and PEDro were used for quality assessment of eligible studies. Clinical and cost effectiveness was determined by extracting and examining self-reported outcomes for pain, function, quality of life (QoL) and health care utilisation. The date range for the search was from database inception until August 2015. The search identified 1148 individual titles of which four were included in the review. A narrative review was conducted due to the heterogeneity of the included trials. Each of the four trials used either educational or exercise interventions facilitated by a range of different health disciplines. Moderate clinical benefits on pain, function and QoL were reported across the studies. The beneficial effects of exercise generally decreased over time within all studies. Two studies were able to show a reduction in healthcare utilisation due to a reduction in visits to a physiotherapist or a reduction in x-rays and orthopaedic referrals. The intervention that showed the most promise used educational interventions delivered by GPs with reinforcement by practice nurses. There are currently very few studies that target multidisciplinary approaches suitable for OA across multiple joint sites, in primary care. A more consistent approach to outcome measurement in future studies of this nature should be considered to allow for better comparison.

Microbial diversity and ecotoxicity of sediments 3 years after the Jiaozhou Bay oil spill.

PubMed

Gao, Wei; Yin, Xiaofei; Mi, Tiezhu; Zhang, Yiran; Lin, Faxiang; Han, Bin; Zhao, Xilong; Luan, Xiao; Cui, Zhisong; Zheng, Li

2018-05-09

In 2013, the "Qingdao oil pipeline explosion" released an estimated 2000 tons of oil into the environment. Sediment samples were collected from ten sites in Jiaozhou Bay and Shilaoren Beach to evaluate the influence of the spilled oil on the benthic environment 3 years after the oil spill accident. The compositions of oil, bacterial diversity and biotoxicity were examined in this study. The results showed that the concentration of total petroleum hydrocarbons (TPHs) peaked near the oil leak point and gradually decreased along the coastline, ranging from 21.5 to 133.2 μg/g. The distribution of polycyclic aromatic hydrocarbons (PAHs) was correlated with TPH, and naphthalenes were dominant in the 20 detected PAHs. The bacterial diversities in seriously polluted and slightly polluted sediments were completely different. As degrading bacteria, Alcanivorax and Lutibacter were the main genera at the oil-polluted sites. The analysis of biotoxicity by the luminescent bacteria method showed great differences among the polluted sites, the control site in Jiaozhou Bay, and the non-polluted site outside of Jiaozhou Bay. The biotoxicity also peaked at the site near the oil leak point. These results indicate that the oil spill that occurred 3 years ago still affects the environment and impacts the bacterial communities in the sediments.

Multi-year levels and trends of non-methane hydrocarbon concentrations observed in ambient air in France

NASA Astrophysics Data System (ADS)

Waked, Antoine; Sauvage, Stéphane; Borbon, Agnès; Gauduin, Julie; Pallares, Cyril; Vagnot, Marie-Pierre; Léonardis, Thierry; Locoge, Nadine

2016-09-01

Measurements of 31 non-methane hydrocarbons (NMHCs) were carried out at three urban (Paris, 2003-2014, Strasbourg, 2002-2014 and Lyon, 2007-2014) sites in France over the period of a decade. A trend analysis was applied by means of the Mann-Kendall non-parametric test to annual and seasonal mean concentrations in order to point out changes in specific emission sources and to assess the impact of emission controls and reduction strategies. The trends were compared to those from three rural sites (Peyrusse-Vieille, 2002-2013, Tardière, 2003-2013 and Donon, 1997-2007). The results obtained showed a significant yearly decrease in pollutant concentrations over the study period and for the majority of species in the range of -1 to -7% in accordance with the decrease of NMHC emissions in France (-5 to -9%). Concentrations of long-lived species such as ethane and propane which are recognized as tracers of distant sources and natural gas remained constant. Compounds associated with combustion processes such as acetylene, propene, ethylene and benzene showed a significant decline in the range of -2% to -5% yr-1. These trends are consistent with those recently described at urban and background sites in the northern mid-latitudes and with emission inventories. C7-C9 aromatics such as toluene and xylenes as well as C4-C5 alkanes such as isopentane and isobutane also showed a significant decrease in the range of -3% to -7% yr-1. The decreasing trends in terms of % yr-1 observed at these French urban sites were typically higher for acetylene, ethylene and benzene than those reported for French rural sites of the national observatory of Measurement and Evaluation in Rural areas of trans-boundary Air pollution (MERA). The study also highlighted the difficult choice of a long term sampling site representative of the general trends of pollutant concentrations.

/sup 3/H)pirenzepine and (-)-(/sup 3/H)quinuclidinyl benzilate binding to rat cerebral cortical and cardiac muscarinic cholinergic sites. I. Characterization and regulation of agonist binding to putative muscarinic subtypes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watson, M.; Yamamura, H.I.; Roeske, W.R.

The binding and regulation of selected muscarinic agonists to putative subtypes in rat cerebral cortex and heart were studied. Parallel inhibition studies of (/sup 3/H)pirenzepine ((/sup 3/H)PZ) and (-)-(/sup 3/H)quinuclidinylbenzilate ((-)-(/sup 3/H)QNB)-labeled membranes were done with and without 30 microM guanyl-5'-yl imidodiphosphate (Gpp(NH)p) at 25 degrees C in 10 mM Na-K-phosphate buffer which enhances PZ binding affinity and in modified Krebs-phosphate buffer, which mimics physiological conditions. Classical agonists such as carbachol, oxotremorine and acetylcholine inhibited (-)-(/sup 3/H)QNB binding to membranes with shallow Hill values (nH less than 1), were better fit to a 2-state model, were Gpp(NH)p-regulated and showed lowermore » affinity in modified Krebs-phosphate buffer than in 10 mM Na-K-phosphate buffer. Some agonists were not significantly better fit to a 2-state model in (/sup 3/H)PZ-labeled cortical membranes, especially in 10 mM Na-K-phosphate buffer. Whereas putative M1 and M2 binding sites distinguished by PZ possessed multiple agonist affinity states, as judged by carbachol, and agonist binding to (/sup 3/H)PZ-labeled sites were Gpp(NH)p modulated, the partial agonist pilocarpine and nonclassical agonist McN-A-343 (3-(m-chlorophenylcarbamoyloxy)-2-butynyl trimethylammonium chloride) showed little Gpp(NH)p-induced shift in (/sup 3/H)PZ-labeled cortical membranes in physiological conditions. Agonist binding to (-)-(/sup 3/H)QNB-labeled putative M2 cardiac sites was more sensitive to Gpp(NH)p than (-)-(/sup 3/H)QNB-labeled cortical sites. Carbachol and acetylcholine showed significant selectivity for putative M2 sites.« less

Microdensitometry to identify saline rangelands on 70-mm color-infrared aerial film

NASA Technical Reports Server (NTRS)

Everitt, J. H.; Gerbermann, A. H.; Alaniz, M. A.

1981-01-01

Many of the world's rangelands are affected by salinity. The detection of these areas is important to range and resource managers who are concerned with productivity, condition, and animal carrying capacity. The reported study was conducted along a north-to-south flight line 24 km long and 1.6 wide in Starr County, TX. Everitt et al. (1977) described seven different native range sites (four nonsaline and three saline) along this flight line. The study showed that photointerpretation by microdensitometry could be used to identify saline range sites quantitatively on CIR (0.50 to 0.90 micrometers) aerial film (scales 1:19,000, 1:42,000, and 1:80,000) exposed in May 1976, June 1976, and June 1979. Microdensitometer readings made on CIR film using white or blue light generally gave the best separation between saline and nonsaline range sites. The differences in microdensitometry readings among saline and nonsaline range sites were caused by less plant cover on the saline sites.

Localization of the 5S and 45S rDNA Sites and cpDNA Sequence Analysis in Species of the Quadrifaria Group of Paspalum (Poaceae, Paniceae)

PubMed Central

VAIO, MAGDALENA; SPERANZA, PABLO; VALLS, JOSÉ FRANCISCO; GUERRA, MARCELO; MAZZELLA, CRISTINA

2005-01-01

• Background and Aims The Quadrifaria group of Paspalum (Poaceae, Paniceae) comprises species native to the subtropical and temperate regions of South America. The purpose of this research was to characterize the I genomes in five species of this group and to establish phylogenetic relationships among them. • Methods Prometaphase chromatin condensation patterns, the physical location of 5S and 45S rDNA sites by fluorescence in situ hybridization (FISH), and sequences of five chloroplast non-coding regions were analysed. • Key Results The condensation patterns observed were highly conserved among diploid and tetraploid accessions studied and not influenced by the dyes used or by the FISH procedure, allowing the identification of almost all the chromosome pairs that carried the rDNA signals. The FISH analysis of 5S rDNA sites showed the same localization and a correspondence between the number of sites and ploidy level. In contrast, the distribution of 45S rDNA sites was variable. Two general patterns were observed with respect to the location of the 45S rDNA. The species and cytotypes Paspalum haumanii 2x, P. intermedium 2x, P. quadrifarium 4x and P. exaltatum 4x showed proximal sites on chromosome 8 and two to four distal sites in other chromosomes, while P. quarinii 4x and P. quadrifarium 2x showed only distal sites located on a variable number of small chromosomes and on the long arm of chromosome 1. The single most-parsimonious tree found from the phylogenetic analysis showed the Quadrifaria species partitioned in two clades, one of them includes P. haumanii 2x and P. intermedium 2x together with P. quadrifarium 4x and P. exaltatum 4x, while the other contains P. quadrifarium 2x and P. quarinii 4x. • Conclusions The subdivision found with FISH is consistent with the clades recovered with cpDNA data and both analyses suggest that the Quadrifaria group, as presently defined, is not monophyletic and its species belong in at least two clades. PMID:15911540

Assessment of wadeable stream resources in the driftless area ecoregion in Western Wisconsin using a probabilistic sampling design.

PubMed

Miller, Michael A; Colby, Alison C C; Kanehl, Paul D; Blocksom, Karen

2009-03-01

The Wisconsin Department of Natural Resources (WDNR), with support from the U.S. EPA, conducted an assessment of wadeable streams in the Driftless Area ecoregion in western Wisconsin using a probabilistic sampling design. This ecoregion encompasses 20% of Wisconsin's land area and contains 8,800 miles of perennial streams. Randomly-selected stream sites (n = 60) equally distributed among stream orders 1-4 were sampled. Watershed land use, riparian and in-stream habitat, water chemistry, macroinvertebrate, and fish assemblage data were collected at each true random site and an associated "modified-random" site on each stream that was accessed via a road crossing nearest to the true random site. Targeted least-disturbed reference sites (n = 22) were also sampled to develop reference conditions for various physical, chemical, and biological measures. Cumulative distribution function plots of various measures collected at the true random sites evaluated with reference condition thresholds, indicate that high proportions of the random sites (and by inference the entire Driftless Area wadeable stream population) show some level of degradation. Study results show no statistically significant differences between the true random and modified-random sample sites for any of the nine physical habitat, 11 water chemistry, seven macroinvertebrate, or eight fish metrics analyzed. In Wisconsin's Driftless Area, 79% of wadeable stream lengths were accessible via road crossings. While further evaluation of the statistical rigor of using a modified-random sampling design is warranted, sampling randomly-selected stream sites accessed via the nearest road crossing may provide a more economical way to apply probabilistic sampling in stream monitoring programs.

Inactivation by Phenylglyoxal of the Specific Binding of 1-Naphthyl Acetic Acid with Membrane-Bound Auxin Binding Sites from Maize Coleoptiles

PubMed Central

Navé, Jean-François; Benveniste, Pierre

1984-01-01

The specific binding of 1-[3H]naphthyl acetic acid (NAA) to membrane-bound binding sites from maize (Zea mays cv INRA 258) coleoptiles is inactivated by phenylglyoxal. The inactivation obeys pseudo first-order kinetics. The rate of inactivation is proportional to phenylglyoxal concentration. Under conditions at which significant binding occurs, NAA, R and S-1-naphthyl 2-propionic acids protect the auxin binding site against inactivation by phenylglyoxal. Scatchard analysis shows that the inhibition of binding corresponds to a decrease in the concentration of sites but not in the affinity. The results of the present chemical modification study indicate that at least one arginyl residue is involved in the positively charged recognition site of the carboxylate anion of NAA. PMID:16663499

DOE Office of Scientific and Technical Information (OSTI.GOV)

Picón, A.; Lehmann, C. S.; Bostedt, C.

New capabilities at X-ray free-electron laser facilities allow the generation of two-colour femtosecond X-ray pulses, opening the possibility of performing ultrafast studies of X-ray-induced phenomena. Specifically, the experimental realization of hetero-site-specific X-ray-pump/X-ray-probe spectroscopy is of special interest, in which an X-ray pump pulse is absorbed at one site within a molecule and an X-ray probe pulse follows the X-ray-induced dynamics at another site within the same molecule. In this paper, we show experimental evidence of a hetero-site pump-probe signal. By using two-colour 10-fs X-ray pulses, we are able to observe the femtosecond time dependence for the formation of F ionsmore » during the fragmentation of XeF 2 molecules following X-ray absorption at the Xe site.« less

Like mother, like daughter: inheritance of nest-site location in snakes.

PubMed

Brown, Gregory P; Shine, Richard

2007-04-22

A trait can be passed from parents to offspring even if it has no genetic basis. For example, if daughters return to reproduce at the same sites where they were hatched themselves, nest-site location is consistent within matrilineages. Most cases of natal homing (nest-site philopatry) across generations have been inferred from molecular evidence rather than directly demonstrated, and involve species with low dispersal abilities. However, some animals disperse long distances but then return to their own place of birth to reproduce, based on cues imprinted early in their own development. Our field studies on tropical natricine snakes (Tropidonophis mairii, Colubridae) show that when they are ready to nest, females return to the sites where their mothers were captured pre-nesting, and where they themselves were released as hatchlings.

Quantitative susceptibility mapping of human brain at 3T: a multisite reproducibility study.

PubMed

Lin, P-Y; Chao, T-C; Wu, M-L

2015-03-01

Quantitative susceptibility mapping of the human brain has demonstrated strong potential in examining iron deposition, which may help in investigating possible brain pathology. This study assesses the reproducibility of quantitative susceptibility mapping across different imaging sites. In this study, the susceptibility values of 5 regions of interest in the human brain were measured on 9 healthy subjects following calibration by using phantom experiments. Each of the subjects was imaged 5 times on 1 scanner with the same procedure repeated on 3 different 3T systems so that both within-site and cross-site quantitative susceptibility mapping precision levels could be assessed. Two quantitative susceptibility mapping algorithms, similar in principle, one by using iterative regularization (iterative quantitative susceptibility mapping) and the other with analytic optimal solutions (deterministic quantitative susceptibility mapping), were implemented, and their performances were compared. Results show that while deterministic quantitative susceptibility mapping had nearly 700 times faster computation speed, residual streaking artifacts seem to be more prominent compared with iterative quantitative susceptibility mapping. With quantitative susceptibility mapping, the putamen, globus pallidus, and caudate nucleus showed smaller imprecision on the order of 0.005 ppm, whereas the red nucleus and substantia nigra, closer to the skull base, had a somewhat larger imprecision of approximately 0.01 ppm. Cross-site errors were not significantly larger than within-site errors. Possible sources of estimation errors are discussed. The reproducibility of quantitative susceptibility mapping in the human brain in vivo is regionally dependent, and the precision levels achieved with quantitative susceptibility mapping should allow longitudinal and multisite studies such as aging-related changes in brain tissue magnetic susceptibility. © 2015 by American Journal of Neuroradiology.

Enhancement of plaque removal by baking soda toothpastes from less accessible areas in the dentition.

PubMed

Thong, S; Hooper, W; Xu, Y; Ghassemi, A; Winston, A

2011-01-01

To determine if baking soda toothpastes are relatively more effective than non-baking soda toothpastes in promoting plaque removal from less accessible sites in the dentition. Several single-brushing comparisons of baking soda and non-baking soda toothpastes for their overall ability to remove plaque have been published. In this study, individual comparisons of these published data, comparing the plaque removal performance of baking soda and non-baking soda toothpastes at various sites in the dentition, were examined to see if there were any site-dependant performance trends. The site-specific single-brushing data were then combined and analyzed in two ways. Meta-analyses of the clinical studies were performed to compare baking soda's relative plaque removal advantage at various sites in the mouth using paired t-testing at p <0.05. Also, plaque index reductions at various sites due to brushing with baking soda toothpastes were graphically compared with plaque index reductions due to brushing with non-baking soda dentifrices. The percent relative plaque removal advantage for baking soda toothpastes at various sites were plotted against the reduction in plaque index due to brushing with non-baking soda toothpastes. Individual comparisons showed that brushing with the toothpastes containing baking soda generally removed significantly more plaque from each site than brushing with toothpastes without baking soda. The relative efficacy advantage for baking soda toothpastes was consistently higher at sites where the non-baking soda toothpastes removed less plaque. Meta-analytical comparisons confirmed baking soda toothpastes to be relatively more effective in enhancing plaque removal from sites where less plaque was removed compared to brushing with non-baking soda toothpastes (p < 0.05). Graphically, the baking soda toothpastes' relative plaque removal advantage could be seen to increase hyperbolically with decreasing plaque removal by the non-baking soda toothpastes with which they were compared. We presuppose that the reason less plaque is removed by non-baking soda toothpastes at some sites than others is that these sites are less accessible to the toothbrush. These results show that baking soda toothpastes are relatively more effective in enhancing plaque removal from harder-to-reach areas of the dentition (p <0.05), i.e., from lingual than facial surfaces, from posterior than anterior areas, and from proximal than mid-surface sites.

Digital divide 2.0: the role of social networking sites in seeking health information online from a longitudinal perspective.

PubMed

Feng, Yang; Xie, Wenjing

2015-01-01

Adopting a longitudinal angle, this study analyzed data from the Pew Internet's Health Tracking Survey in 2006, 2008, and 2010 to identify potential communication inequalities in social networking site use. Results showed that with the growing role of social networking site use in predicting people's likelihood of seeking health information online, the socioeconomic and demographic factors that contributed to the disparities in social networking site use could also lead to disparities in seeking health information online. Also, results indicated that people are more likely to seek heath-related information online if they or their close family or friends have a chronic disease situation.

The MGTX Experience: Challenges in Planning and Executing an International, Multicenter Clinical Trial

PubMed Central

Aban, Inmaculada B.; Wolfe, Gil I.; Cutter, Gary R.; Kaminski, Henry J.; Jaretzki, Alfred; Minisman, Greg; Conwit, Robin; Newsom-Davis, John

2008-01-01

We present our experience planning and launching a multinational, NIH/NINDS funded study of thymectomy in myasthenia gravis. We highlight the additional steps required for international sites and analyze and contrast the time investment required to bring U.S. and non-U.S. sites into full regulatory compliance. Results show the mean time for non- U.S. centers to achieve regulatory approval was significantly longer (mean 13.4 ± 0.96 months) than for U.S. sites (9.67 ± 0.74 months; p = 0.003, t-test). The delay for non- U.S. sites was mainly attributable to Federalwide Assurance certification and State Department clearance. PMID:18675464

Selected nutrients and pesticides in streams of the eastern Iowa basins, 1970-95

USGS Publications Warehouse

Schnoebelen, Douglas J.; Becher, Kent D.; Bobier, Matthew W.; Wilton, Thomas

1999-01-01

 The statistical analysis of the nutrient data typically indicated a strong positive correlation of nitrate with streamflow. Total phosphorus concentrations with streamflow showed greater variability than nitrate, perhaps reflecting the greater potential of transport of phosphorus on sediment rather than in the dissolved phase as with nitrate. Ammonia and ammonia plus organic nitrogen showed no correlation with streamflow or a weak positive correlation. Seasonal variations and the relations of nutrients and pesticides to streamflow generally corresponded with nonpoint‑source loadings, although possible point sources for nutrients were indicated by the data at selected monitoring sites. Statistical trend tests for concentrations and loads were computed for nitrate, ammonia, and total phosphorus. Trend analysis indicated decreases for ammonia and total phosphorus concentrations at several sites and increases for nitrate concentrations at other sites in the study unit.

Comparative evaluation of guided tissue regeneration with use of collagen-based barrier freeze-dried dura mater allograft for mandibular class 2 furcation defects (a comparative controlled clinical study).

PubMed

Patel, Sandeep; Kubavat, Ajay; Ruparelia, Brijesh; Agarwal, Arvind; Panda, Anup

2012-01-01

The aim of periodontal surgery is complete regeneration. The present study was designed to evaluate and compare clinically soft tissue changes in form of probing pocket depth, gingival shrinkage, attachment level and hard tissue changes in form of horizontal and vertical bone level using resorbable membranes. Twelve subjects with bilateral class 2 furcation defects were selected. After initial phase one treatment, open debridement was performed in control site while freezedried dura mater allograft was used in experimental site. Soft and hard tissue parameters were registered intrasurgically. Nine months reentry ensured better understanding and evaluation of the final outcome of the study. Guided tissue regeneration is a predictable treatment modality for class 2 furcation defect. There was statistically significant reduction in pocket depth as compared to control (p < 0.01). There is statistically significant increase in periodontal attachment level within control and experimental sites showed better results (p < 0.01). For hard tissue parameter, significant defect fill resulted in experimental group, while in control group, less significant defect fill was found in horizontal direction and nonsignificant defect fill was found in vertical direction. The results showed statistically significant improvement in soft and hard tissue parameters and less gingival shrinkage in experimental sites compared to control site. The use of FDDMA in furcation defects helps us to achieve predictable results. This cross-linked collagen membrane has better handling properties and ease of procurement as well as economic viability making it a logical material to be used in regenerative surgeries.

Quantifying Apparent Groundwater Ages near Managed Aquifer Recharge Operations Using Radio-Sulfur ( 35S) as an Intrinsic Tracer

DOE PAGES

Clark, Jordan; Urióstegui, Stephanie; Bibby, Richard; ...

2016-10-25

The application of the cosmogenic radioisotope sulfur-35 ( 35S) as a chronometer near spreading basins is evaluated at two well-established Managed Aquifer Recharge (MAR) sites: the Atlantis facility (South Africa) and Orange County Water District’s (OCWD’s) Kraemer Basin (Northern Orange County, CA, USA). Source water for both of these sites includes recycled wastewater. Despite lying nearer to the outlet end of their respective watersheds than to the headwaters, 35S was detected in most of the water sampled, including from wells found close to the spreading ponds and in the source water. Dilution with 35S-dead continental SO 4 was minimal, amore » surprising finding given its short ~3 month half-life. The initial work at the Atlantis MAR site demonstrated that remote laboratories could be set up and that small volume samples—saline solutions collected after the resin elution step from the recently developed batch method described below—can be stored and transported to the counting laboratory. This study also showed that the batch method needed to be altered to remove unknown compounds eluted from the resin along with SO 4. Using the improved batch method, times series measurements of both source and well water from OCWD’s MAR site showed significant temporal variations. Finally, this result indicates that during future studies, monthly to semi-monthly sampling should be conducted. Nevertheless, both of these initial studies suggest the 35S chronometer may become a valuable tool for managing MAR sites where regulations require minimum retention times.« less

The Long-Term Safety of S-Flurbiprofen Plaster for Osteoarthritis Patients: An Open-Label, 52-Week Study.

PubMed

Yataba, Ikuko; Otsuka, Noboru; Matsushita, Isao; Matsumoto, Hideo; Hoshino, Yuichi

2016-08-01

The newly developed S-flurbiprofen plaster (SFPP) is a tape-type patch that shows innovative percutaneous absorption. This study was designed to evaluate the safety of a long-term 52-week SFPP application to osteoarthritis (OA) patients. This was a multi-center, open-label, uncontrolled prospective study that included 201 OA patients. SFPP at 40 mg/day was applied to the site of pain in 101 patients and at 80 mg/day (2 patches) in 100 patients at a total of 301 sites for 52 weeks. The affected sites assessed included the knee (192), lumbar spine (66), cervical spine (26), and others (17). Drug safety was evaluated by medical examination, laboratory tests, and examination of vital signs. Efficacy was evaluated by the patient's and clinician's global assessments and clinical symptoms. Most patients (80.1 %) completed the 52-week SFPP application. The majority of drug-related adverse events (AEs) included mild dermatitis at the application sites and occurred in 46.8 % of the sites. No photosensitive dermatitis was observed. Systemic AEs occurred in 9.0 % of the patients; a serious AE (gastric ulcer hemorrhage) occurred in one patient. No clinically significant changes in the laboratory tests and vital signs were observed. The efficacy evaluation showed an improvement from 2 weeks after the SFPP application, which continued during the 52 weeks' treatment. No apparent safety concerns were observed, even during the long-term SFPP application. Therefore, SFPP could be an additional pharmacotherapy in OA treatment.

Quantifying Apparent Groundwater Ages near Managed Aquifer Recharge Operations Using Radio-Sulfur ( 35S) as an Intrinsic Tracer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clark, Jordan; Urióstegui, Stephanie; Bibby, Richard

The application of the cosmogenic radioisotope sulfur-35 ( 35S) as a chronometer near spreading basins is evaluated at two well-established Managed Aquifer Recharge (MAR) sites: the Atlantis facility (South Africa) and Orange County Water District’s (OCWD’s) Kraemer Basin (Northern Orange County, CA, USA). Source water for both of these sites includes recycled wastewater. Despite lying nearer to the outlet end of their respective watersheds than to the headwaters, 35S was detected in most of the water sampled, including from wells found close to the spreading ponds and in the source water. Dilution with 35S-dead continental SO 4 was minimal, amore » surprising finding given its short ~3 month half-life. The initial work at the Atlantis MAR site demonstrated that remote laboratories could be set up and that small volume samples—saline solutions collected after the resin elution step from the recently developed batch method described below—can be stored and transported to the counting laboratory. This study also showed that the batch method needed to be altered to remove unknown compounds eluted from the resin along with SO 4. Using the improved batch method, times series measurements of both source and well water from OCWD’s MAR site showed significant temporal variations. Finally, this result indicates that during future studies, monthly to semi-monthly sampling should be conducted. Nevertheless, both of these initial studies suggest the 35S chronometer may become a valuable tool for managing MAR sites where regulations require minimum retention times.« less

Experience in Grid Site Testing for ATLAS, CMS and LHCb with HammerCloud

NASA Astrophysics Data System (ADS)

Elmsheuser, Johannes; Medrano Llamas, Ramón; Legger, Federica; Sciabà, Andrea; Sciacca, Gianfranco; Úbeda García, Mario; van der Ster, Daniel

2012-12-01

Frequent validation and stress testing of the network, storage and CPU resources of a grid site is essential to achieve high performance and reliability. HammerCloud was previously introduced with the goals of enabling VO- and site-administrators to run such tests in an automated or on-demand manner. The ATLAS, CMS and LHCb experiments have all developed VO plugins for the service and have successfully integrated it into their grid operations infrastructures. This work will present the experience in running HammerCloud at full scale for more than 3 years and present solutions to the scalability issues faced by the service. First, we will show the particular challenges faced when integrating with CMS and LHCb offline computing, including customized dashboards to show site validation reports for the VOs and a new API to tightly integrate with the LHCbDIRAC Resource Status System. Next, a study of the automatic site exclusion component used by ATLAS will be presented along with results for tuning the exclusion policies. A study of the historical test results for ATLAS, CMS and LHCb will be presented, including comparisons between the experiments’ grid availabilities and a search for site-based or temporal failure correlations. Finally, we will look to future plans that will allow users to gain new insights into the test results; these include developments to allow increased testing concurrency, increased scale in the number of metrics recorded per test job (up to hundreds), and increased scale in the historical job information (up to many millions of jobs per VO).

Effectiveness of a physical barrier for contaminant control in an unconfined coastal plain aquifer: the case study of the former industrial site of Bagnoli (Naples, southern Italy).

PubMed

Arienzo, Michele; Allocca, Vincenzo; Manna, Ferdinando; Trifuoggi, Marco; Ferrara, Luciano

2015-12-01

A vertical engineered barrier (VEB) coupled with a water treatment plant was surveyed in the framework of a vast remedial action at the brownfield site of the former ILVA of Bagnoli steel making facility located in western Naples, Italy. The VEB was put in place to minimize contaminant migration from the brownfield site toward the sea at the shorelines sites of Bagnoli and Coroglio. The efficiency of the VEB was monitored through 12 piezometers, 8 at the Bagnoli shoreline and 4 at the Coroglio shoreline. Concentrations of inorganic and organic pollutants were examined in upstream and downstream groundwater relative to the VEB. The mean levels of Al, As, Fe, and Mn largely exceeded the legal limits, 10-15-fold, whereas that of Hg was up to 3-fold the rules. The VEB decreased the outlet concentrations only at certain specific location of the barrier, four times for Al, 6-fold for Hg, and by 20% for Mn with means largely exceeding the rules. At the other sites, the downstream water showed marked increases of the pollutants up to 3-fold. Outstanding levels of the hydrocarbons > 12 were detected in the inlet water with means of some hundred times the limits at both sites. Likewise most of screened inorganic pollutants, the downstream water showed marked increases of the hydrocarbons up to ~113%. The treatment plant was very effective, with removal efficiencies >80% for As, Al, Fe, and Mn. The study evidenced the need to put alternative groundwater remedial actions.

Revascularization of the anterior cerebral artery by Y-shaped superficial temporal artery interposition graft for the treatment of a de novo aneurysm arising at the site of A3-A3 bypass: technical case report.

PubMed

Endo, Hidenori; Sugiyama, Shin-Ichiro; Endo, Toshiki; Fujimura, Miki; Shimizu, Hiroaki; Tominaga, Teiji

2017-12-22

The most frequently used option to reconstruct the anterior cerebral artery (ACA) is an ACA-ACA side-to-side anastomosis. The long-term outcome and complications of this technique are unclear. The authors report a case of a de novo aneurysm arising at the site of A 3 -A 3 anastomosis. A 53-year-old woman underwent A 3 -A 3 side-to-side anastomosis for the treatment of a ruptured right A 2 dissecting aneurysm. At 44 months after surgery, a de novo aneurysm developed at the site of anastomosis. The aneurysm developed in the front wall of the anastomosis site, and projected to the anterosuperior direction. A computational fluid dynamics (CFD) study showed the localized region with high wall shear stress coincident with the pulsation in the front wall of the anastomosis site, where the aneurysm developed. A Y-shaped superficial temporal artery (STA) interposition graft was used successfully to reconstruct both ACAs, and then the aneurysm was trapped. To the authors' knowledge, this is the first case of a de novo aneurysm that developed at the site of an ACA-ACA side-to-side anastomosis. A CFD study showed that hemodynamic stress might be an underlying cause of the aneurysm formation. A Y-shaped STA interposition graft is a useful option to treat this aneurysm. Long-term follow-up is necessary to detect this rare complication after ACA-ACA anastomosis.

[Analysis of the web pages of the intensive care units of Spain].

PubMed

Navarro-Arnedo, J M

2009-01-01

In order to determine the Intensive Care Units (ICU) of Spanish hospitals that had a web site, to analyze the information they offered and to know what information they needed to offer according to a sample of ICU nurses, a cross-sectional observational, descriptive study was carried out between January and September 2008. For each ICU website, an analysis was made on the information available on the unit, its care, teaching and research activity on nursing. Simultaneously, based on a sample of intensive care nurses, the information that should be contained on an ICU website was determined. The results, expressed in absolute numbers and percentage, showed that 66 of the 292 hospitals with ICU (22.6%) had a web site; 50.7% of the sites showed the number of beds, 19.7% the activity report, 11.3% the published articles/studies and followed research lines and 9.9% the organized formation courses. 14 webs (19.7%) displayed images of nurses. However, only 1 (1.4%) offered guides on the actions followed. No web site offered a navigation section for nursing, the E-mail of the chief nursing, the nursing documentation used or if any nursing model of their own was used. It is concluded that only one-fourth of the Spanish hospitals with ICU have a web site; number of beds was the data offered by the most sites, whereas information on care, educational and investigating activities was very reduced and that on nursing was practically omitted on the web pages of intensive care units.

A modelling study of the seasonal snowpack energy balance at three sites along the Andes Cordillera. Regional climate and local effects.

NASA Astrophysics Data System (ADS)

McPhee, James; Mengual, Sebastian; MacDonell, Shelley

2017-04-01

Seasonal snowpack melt constitutes the main water source for large portions of extratropical South America, including central Chile and Western Argentina. The properties and distribution of snow in the Andes are threatened by rapid climate change, characterised by warming and drying. This study provides a first attempt at detailed description of the energy balance of the seasonal snowpack and its variability along a latitudinal gradient, which is also correlated with an elevation and precipitation gradient, in the Andes Cordillera. The Snowpack model was validated at semi-arid, Mediterranean and temperate humid sites, where meteorological and snowpack properties have been observed since year 2013. Site elevations decrease from north to south, whereas precipitation climatology increases with latitude. Results show that turbulent energy exchange becomes relatively more important in periods of low snow accumulation, with sensible heat fluxes having a greater effect in cooling the snowpack at the high-altitude, low latitude site. Likewise, daily melt-freeze cycles are important in maintaining positive cold contents throughout the accumulation season at this site, and contribute to extending the duration of snow cover despite low accumulation and high radiation loads. In contrast, the southernmost, lowest elevation site shows smaller daily temperature amplitude and a much more preponderant radiation component to the energy balance. This modelling exercise highlights the nonlinearities of snow dynamics at different geographical settings in a sparsely monitored mountain area of the world, as well as the need for further understanding in order to evaluate the sensitivity of snow-dominated watersheds to global warming and climate change.

Did municipal solid waste landfill have obvious influence on polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in ambient air: A case study in East China.

PubMed

Li, Jiafu; Wang, Chong; Du, Lei; Lv, Zhiwei; Li, Xiaonan; Hu, Xuepeng; Niu, Zhiguang; Zhang, Ying

2017-04-01

Municipal solid waste (MSW) landfill was a main way to disposal of MSW and almost 95% of MSW was disposed by landfills in the world. In order to understand the influence of MSW landfill on polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in surrounding atmosphere, 42 ambient air samples were collected and analyzed from surrounding sites, background site, upwind site and downwind site of a MSW landfill in East China. The results of present study were summarized as follows. (1) The total concentrations of PCDD/Fs (∑PCDD/Fs) in ambient air from surrounding sites, background site, upwind site and downwind site were 2.215±1.004, 2.058±0.458, 2.617±1.092 and 1.822±0.566pgNm -3 , respectively. (2) The toxic equivalent concentrations (TEQ) of PCDD/Fs in ambient air from surrounding sites, background site, upwind site and downwind site were 0.103±0.017, 0.096±0.015, 0.120±0.024 and 0.108±0.014pg I-TEQNm -3 , respectively. (3) The congener profiles, ∑PCDD/Fs and TEQ between background atmosphere and surrounding atmosphere of landfill did not show statistically significant difference. (4) The ∑PCDD/Fs and TEQ in ambient air of downwind site were not higher than that of upwind site, suggesting that studied landfill did not have obvious influence on PCDD/Fs in ambient air from downwind site. (5) The 95th percentile carcinogenic risk (CR) of PCDD/Fs in ambient air from surrounding sites, background site, upwind site and downwind site were 8.03×10 -9 , 7.57×10 -9 , 9.69×10 -9 and 8.15×10 -9 , respectively, which were much lower than the threshold value of CR (10 -6 ), suggesting that studied landfill did not influence the CR of PCDD/Fs in surrounding atmosphere and negligible cancer risk occurred. (6) The non-carcinogenic risk (non-CR) analysis indicated that landfill did not have influence on the non-CR of PCDD/Fs in surrounding atmosphere and no obvious non-carcinogenic effects developed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synchrotron micro-scale measurement of metal distributions in Phragmites australis and Typha latifolia root tissue from an urban brownfield site

DOE PAGES

Feng, Huan; Qian, Yu; Gallagher, Frank J.; ...

2015-11-01

Liberty State Park in New Jersey, USA, is a “brownfield” site containing various levels of contaminants. To investigate metal uptake and distributions in plants on the brownfield site, Phragmites australis and Typha latifolia were collected in Liberty State Park during the growing season (May–September) in 2011 at two sites with the high and low metal loads, respectively. The objective of this study was to understand the metal (Fe, Mn, Cu, Pb and Zn) concentration and spatial distributions in P. australis and T. latifolia root systems with micro-meter scale resolution using synchrotron X-ray microfluorescence (μXRF) and synchrotron X-ray computed microtomography (μCMT)more » techniques. The root structure measurement by synchrotron μCMT showed that high X-ray attenuation substance appeared in the epidermis. Synchrotron μXRF measurement showed that metal concentrations and distributions in the root cross-section between epidermis and vascular tissue were statistically different. Significant correlations were found between metals (Cu, Mn, Pb and Zn) and Fe in the epidermis, implying that metals were scavenged by Fe oxides. The results from this study suggest that the expression of metal transport and accumulation within the root systems may be element specific. The information derived from this study can improve our current knowledge of the wetland plant ecological function in brownfield remediation.« less

Asbestos concentrations two years after abatement in seventeen schools. Final summary report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kominsky, J.R.; Freyberg, R.W.; Brownlee, J.A.

Airborne asbestos concentrations were measured at 17 schools that underwent an asbestos abatement 2 years before in 1988. These 17 schools, which involved 20 abatement sites, were part of a study conducted by the U.S. Environmental Protection Agency (EPA) and the New Jersey Department of Health (NJDOH) in 1988. The 1988 study showed that asbestos concentrations measured independently by the NJDOH and EPA during the clearance phase of the abatement were elevated in the abatement and perimeter areas compared with outdoor concentrations. The present study was conducted to determine the current levels of airborne asbestos under simulated occupancy conditions andmore » to determine whether the elevated levels found during the clearance phase were still present 2 years after abatement. In 1990, four sites showed significantly higher mean asbestos concentrations inside the building (i.e., the previously abated area and/or perimeter area) compared with those outdoors (p<0.05). In 1990, the mean asbestos concentration measured in the perimeter area at one site and in the previously abated area at two sites were significantly higher than those in 1988 (p<0.05). Variations in asbestos levels between 1988 and 1990 may be due to sampling techniques (passive and aggressive versus modified aggressive), residual air-entrainable asbestos from the 1988 abatement, or air-entrainable asbestos from operations and maintenance activities since 1988.« less

The influence of the loop between residues 223-235 in beetle luciferase bioluminescence spectra: a solvent gate for the active site of pH-sensitive luciferases.

PubMed

Viviani, Vadim R; Silva Neto, Antonio J; Arnoldi, Frederico G C; Barbosa, João A R G; Ohmiya, Yoshihiro

2008-01-01

Beetle luciferases emit a wide range of bioluminescence colors, ranging from green to red. Firefly luciferases can shift the spectrum to red in response to pH and temperature changes, whereas click beetle and railroadworm luciferases do not. Despite many studies on firefly luciferases, the origin of pH-sensitivity is far from being understood. Through comparative site-directed mutagenesis and modeling studies, using the pH-sensitive luciferases (Macrolampis and Cratomorphus distinctus fireflies) and the pH-insensitive luciferases (Pyrearinus termitilluminans, Phrixotrix viviani and Phrixotrix hirtus) cloned by our group, here we show that substitutions dramatically affecting bioluminescence colors in both groups of luciferases are clustered in the loop between residues 223-235 (Photinus pyralis sequence). The substitutions at positions 227, 228 and 229 (P. pyralis sequence) cause dramatic redshift and temporal shift in both groups of luciferases, indicating their involvement in labile interactions. Modeling studies showed that the residues Y227 and N229 are buried in the protein core, fixing the loop to other structural elements participating at the bottom of the luciferin binding site. Changes in pH and temperature (in firefly luciferases), as well as point mutations in this loop, may disrupt the interactions of these structural elements exposing the active site and modulating bioluminescence colors.

Is Exposure to an Effective Contingency Management Intervention Associated with More Positive Provider Beliefs?

PubMed Central

Kirby, Kimberly C.; Carpenedo, Carolyn M.; Stitzer, Maxine L.; Dugosh, Karen L.; Petry, Nancy M.; Roll, John M.; Saladin, Michael E.; Cohen, Allan J.; Hamilton, John; Reese, Karen; Sillo, Gina R.; Stabile, Patricia Quinn; Sterling, Robert C.

2011-01-01

This study empirically examined opinions of treatment providers regarding Contingency Management (CM) programs while controlling for experience with a specific efficacious CM program. In addition to empirically describing provider opinions, we examined whether the opinions of providers at the sites that implemented the CM program were more positive than those of matched providers at sites that did not implement it. Participants from 7 CM treatment sites (n = 76) and 7 matched non-participating sites (n = 69) within the same nodes of NIDA's Clinical Trials Network completed the Provider Survey of Incentives (PSI), which assesses positive and negative beliefs about incentive programs. An intent-to-treat analysis found no differences in the PSI summary scores of providers in CM program vs. matched sites, but correcting for experience with tangible incentives showed significant differences, with providers from CM sites reporting more positive opinions than those from matched sites. Some differences were found in opinions regarding costs of incentives and these generally indicated that participants from CM sites were more likely to see the costs as worthwhile. The results from the study suggest that exposing community treatment providers to incentive programs may itself be an effective strategy in prompting the dissemination of CM interventions. PMID:22116009

Anthropogenic impacts on the quality of streambed sediments in the lower Sacramento River watershed, California.

PubMed

Hwang, Hyun-Min; Green, Peter G; Holmes, Robert W

2009-01-01

To investigate the occurrence of contaminants and to assess their toxicity potential to benthic organisms, streambed sediments were collected from three agricultural and one urban influenced small waterways in the lower Sacramento River watershed and analyzed for PAHs, organochlorine (OC) and organophosphorus (OP) pesticides, pyrethroids, and metals. These sites had low benthic biotic index scores in earlier field surveys. The occurrence patterns of these contaminants and iron normalized enrichment factors of metals reflect the land use patterns around study sites. DDTs were detected in all samples while chlordanes were found only at the urban influenced site. No OP pesticides were found in any sediment presumably due to their high water solubilities and low solid-water partitioning. DDTs, PAHs, and metals at sites in the Biggs/West Gridley Canal showed a gradient increasing toward downstream. Distribution patterns of individual PAHs and their ratios found in sediment from the Biggs/West Gridley Canal downstream site resemble those of petroleum. PAHs in this site might originate from petroleum oils that have been used as agricultural pesticides. The enrichment factor of vanadium, which is an indicator of petroleum residue, was also higher in this site. The anthropogenic enrichment of copper at all Biggs/West Gridley Canal sites might be because of significant use of copper based pesticides. The high enrichment factor of lead at the urban influenced Dry Creek site might be related to historical use of leaded gasoline. All sediment samples had at least one chemical that exceed the threshold effects concentration (TEC). Total probable effects concentration quotients (tPECQs) were greater than 1 at all sites, indicating that sediment bound contaminants in the study sites can possibly pose toxic effects. This finding can be linked to lower biotic index scores observed in previous regional monitoring studies.

Biomass, community structure and nutritional status attributes of the deep subsurface microbiota---at Idaho and Hanford sites

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, D.C.; Ringelberg, D.B.

1991-10-28

The signature lipid biomarker technique based on phospholipid ester-linked fatty acid pattern analysis (PLFA) provides data on the total viable or potentially viable communities without the necessity of: (1) Quantitative recovery from the sediments or (2) The ability to culture the organisms. Analysis of PLFA provides evidence for the nutritional status (starvation and/or unbalanced growth) in situ. PLFA analysis of SSP samples from the INEL and PNL sites vadose zones showed higher biomass at the surface with prominent Actinomyces biomarkers with lower biomasses of stressed microbiota at progressively greater depth. The biomass and community diversity increased at the water tablemore » at both sites. Both these Western sites showed lower viable microbial biomasses than the WSRS samples. Cluster analysis of the total patterns from various sedimentary horizons showed three major consortia of microbes, with surface microbiota related at both sites, low viable biomass sites closely related at both sites, with anaerobic desaturase pathway being predominant at INEL and consortia utilizing predominantly branched saturated and the aerobic desaturase pathway at both sites. Preliminary examination of the consortia recovered from NTS show a clear relationship to water level.« less

Salinization of groundwater around underground LPG storage caverns, Korea : statistical interpretation

NASA Astrophysics Data System (ADS)

Lee, J.; Chang, H.

2001-12-01

In this research, we investigate the reciprocal influence between groundwater flow and its salinization occurred in two underground cavern sites, using major ion chemistry, PCA for chemical analysis data, and cross-correlation for various hydraulic data. The study areas are two underground LPG storage facilities constructed in South Sea coast, Yosu, and West Sea coastal regions, Pyeongtaek, Korea. Considerably high concentration of major cations and anions of groundwaters at both sites showed brackish or saline water types. In Yosu site, some great chemical difference of groundwater samples between rainy and dry season was caused by temporal intrusion of high-saline water into propane and butane cavern zone, but not in Pyeongtaek site. Cl/Br ratios and δ 18O- δ D distribution for tracing of salinization source water in both sites revealed that two kind of saline water (seawater and halite-dissolved solution) could influence the groundwater salinization in Yosu site, whereas only seawater intrusion could affect the groundwater chemistry of the observation wells in Pyeongtaek site. PCA performed by 8 and 10 chemical ions as statistical variables in both sites showed that intensive intrusion of seawater through butane cavern was occurred at Yosu site while seawater-groundwater mixing was observed at some observation wells located in the marginal part of Pyeongtaek site. Cross-correlation results revealed that the positive relationship between hydraulic head and cavern operating pressure was far more conspicuous at propane cavern zone in both sites (65 ~90% of correlation coefficients). According to the cross-correlation results of Yosu site, small change of head could provoke massive influx of halite-dissolved solution from surface through vertically developed fracture networks. However in Pyeongtaek site, the pressure-sensitive observation wells are not completely consistent with seawater-mixed wells, and the hydraulic change of heads at these wells related to the operating pressure is highly associated with horizontal fault developed along the east-west line of propane cavern zone.

Population dose commitments due to radioactive releases from nuclear power plant sites in 1988

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1988. Fifty-year commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 71 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km aroundmore » each site receiving various average dose commitments from the airborne pathways. The total collective dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 16 person-rem to a low of 0.0011 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 1.1 person-rem. The total population dose for all sites was estimated at 75 person-rem for the 150 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 3 {times} 10{sup {minus}7} mrem to a high of 0.02 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites. However, licensee calculation of doses to the maximally exposed individual at some sites indicated values of up to approximately 100 times average individual doses (on the order of a few millirem per year).« less

Population dose commitments due to radioactive releases from nuclear power plant sites in 1988. Volume 10

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1988. Fifty-year commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 71 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km aroundmore » each site receiving various average dose commitments from the airborne pathways. The total collective dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 16 person-rem to a low of 0.0011 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 1.1 person-rem. The total population dose for all sites was estimated at 75 person-rem for the 150 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 3 {times} 10{sup {minus}7} mrem to a high of 0.02 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites. However, licensee calculation of doses to the maximally exposed individual at some sites indicated values of up to approximately 100 times average individual doses (on the order of a few millirem per year).« less

Biological responses to contaminants in darters (Etheostoma spp.) collected from rural and urban regions of the Grand River, ON, Canada.

PubMed

Diamond, Sam R; Sultana, Tamanna; Servos, Mark R; Metcalfe, Chris D

2016-09-01

Urban and agricultural activities may introduce chemical stressors, including contaminants of emerging concern (CECs) and current use pesticides (CUPs) into riverine systems. The objective of this study was to determine if fish collected from various sites in the Grand River, ON, Canada show biomarkers of exposure to these classes of contaminants, and if the biomarker patterns vary in fish collected from urbanized and agricultural sites. Female rainbow darters (Etheostoma caeruleum) and female fantail darters (Etheostoma flabellare) were collected from the Grand River in June, 2014 for biomarker analysis from two urbanized sites and three agricultural sites. Over the same period of time, Polar Organic Chemical Integrative Samplers (POCIS) were deployed for 2weeks at each site to monitor for the presence of CUPs and CECs. Data on the liver somatic index for darters indicate site-specific differences in this condition factor (p<0.05). Significant differences in the levels of thiobarbituric acid reactive substances (TBARS) in gill tissue (p<0.05) of darters collected from the various sites indicate site-specific differences in oxidative stress. The activities of ethoxyresorufin-O-deethylase (EROD) in the liver tissue of rainbow darters were significantly different between sites (p<0.05), indicating differences in exposure to chemicals that induce or inhibit CYP450 1A metabolic activity. Finally, acetylcholinesterase (AChE) activity in brain tissue was significantly different between rainbow darters collected from rural and urban sites (p<0.05). These data showing different impacts from chemical inputs related to land uses in the watershed may be useful in developing mitigation strategies to reduce impacts on fish and other aquatic organisms in receiving environments. Copyright © 2016. Published by Elsevier Inc.

Effect of tree line advance on carbon storage in NW Alaska

USGS Publications Warehouse

Wilmking, M.; Harden, J.; Tape, K.

2006-01-01

We investigated the size, distribution, and temporal dynamics of ecosystem carbon (C) pools in an area of recent tree line advance, northwest Alaska. Repeat aerial photographs show forest cover increased ???10% in our study area since 1949. We sampled C pools of four principal ecosystem types, tussock tundra, shrub tundra, woodland, and forest, all located on a 600-800 year old river terrace. Significant differences between ecosystem C pools, both above ground and below ground existed. Tundra sites store >22.2 kg C/m2, shrub tundra sites and woodland sites store 9.7 kg C/m2 and 14.3 kg C/m2, respectively, and forest sites store 14.4 kg C/m2. Landscape variation of total ecosystem C was primarily due to organic soil C and was secondarily due to C stored in trees. Soil C/N profiles of shrub tundra sites and woodland sites showed similarities with forest site soils at surface and tundra site soils at depth. We hypothesize that tundra systems transformed to forest systems in this area under a progression of permafrost degradation and enhanced drainage. On the basis of C pool estimates for the different ecosystem types, conversion of tundra sites to forest may have resulted in a net loss of > 7.8 kg C/m2, since aboveground C gains were more than offset by belowground C losses to decomposition in the tundra sites. Tree line advance therefore might not increase C storage in high-latitude ecosystems and thus might not, as previously suggested, act as a negative feedback to warming. Key to this hypothesis and to its projection to future climate response is the fate of soil carbon upon warming and permafrost drainage. Copyright 2006 by the American Geophysical Union.

Prediction of earthquake ground motion at rock sites in Japan: evaluation of empirical and stochastic approaches for the PEGASOS Refinement Project

NASA Astrophysics Data System (ADS)

Edwards, Benjamin; Fäh, Donat

2017-11-01

Strong ground-motion databases used to develop ground-motion prediction equations (GMPEs) and calibrate stochastic simulation models generally include relatively few recordings on what can be considered as engineering rock or hard rock. Ground-motion predictions for such sites are therefore susceptible to uncertainty and bias, which can then propagate into site-specific hazard and risk estimates. In order to explore this issue we present a study investigating the prediction of ground motion at rock sites in Japan, where a wide range of recording-site types (from soil to very hard rock) are available for analysis. We employ two approaches: empirical GMPEs and stochastic simulations. The study is undertaken in the context of the PEGASOS Refinement Project (PRP), a Senior Seismic Hazard Analysis Committee (SSHAC) Level 4 probabilistic seismic hazard analysis of Swiss nuclear power plants, commissioned by swissnuclear and running from 2008 to 2013. In order to reduce the impact of site-to-site variability and expand the available data set for rock and hard-rock sites we adjusted Japanese ground-motion data (recorded at sites with 110 m s-1 < Vs30 < 2100 m s-1) to a common hard-rock reference. This was done through deconvolution of: (i) empirically derived amplification functions and (ii) the theoretical 1-D SH amplification between the bedrock and surface. Initial comparison of a Japanese GMPE's predictions with data recorded at rock and hard-rock sites showed systematic overestimation of ground motion. A further investigation of five global GMPEs' prediction residuals as a function of quarter-wavelength velocity showed that they all presented systematic misfit trends, leading to overestimation of median ground motions at rock and hard-rock sites in Japan. In an alternative approach, a stochastic simulation method was tested, allowing the direct incorporation of site-specific Fourier amplification information in forward simulations. We use an adjusted version of the model developed for Switzerland during the PRP. The median simulation prediction at true rock and hard-rock sites (Vs30 > 800 m s-1) was found to be comparable (within expected levels of epistemic uncertainty) to predictions using an empirical GMPE, with reduced residual misfit. As expected, due to including site-specific information in the simulations, the reduction in misfit could be isolated to a reduction in the site-related within-event uncertainty. The results of this study support the use of finite or pseudo-finite fault stochastic simulation methods in estimating strong ground motions in regions of weak and moderate seismicity, such as central and northern Europe. Furthermore, it indicates that weak-motion data has the potential to allow estimation of between- and within-site variability in ground motion, which is a critical issue in site-specific seismic hazard analysis, particularly for safety critical structures.

Functional Evolution of PLP-dependent Enzymes based on Active-Site Structural Similarities

PubMed Central

Catazaro, Jonathan; Caprez, Adam; Guru, Ashu; Swanson, David; Powers, Robert

2014-01-01

Families of distantly related proteins typically have very low sequence identity, which hinders evolutionary analysis and functional annotation. Slowly evolving features of proteins, such as an active site, are therefore valuable for annotating putative and distantly related proteins. To date, a complete evolutionary analysis of the functional relationship of an entire enzyme family based on active-site structural similarities has not yet been undertaken. Pyridoxal-5’-phosphate (PLP) dependent enzymes are primordial enzymes that diversified in the last universal ancestor. Using the Comparison of Protein Active Site Structures (CPASS) software and database, we show that the active site structures of PLP-dependent enzymes can be used to infer evolutionary relationships based on functional similarity. The enzymes successfully clustered together based on substrate specificity, function, and three-dimensional fold. This study demonstrates the value of using active site structures for functional evolutionary analysis and the effectiveness of CPASS. PMID:24920327

Functional evolution of PLP-dependent enzymes based on active-site structural similarities.

PubMed

Catazaro, Jonathan; Caprez, Adam; Guru, Ashu; Swanson, David; Powers, Robert

2014-10-01

Families of distantly related proteins typically have very low sequence identity, which hinders evolutionary analysis and functional annotation. Slowly evolving features of proteins, such as an active site, are therefore valuable for annotating putative and distantly related proteins. To date, a complete evolutionary analysis of the functional relationship of an entire enzyme family based on active-site structural similarities has not yet been undertaken. Pyridoxal-5'-phosphate (PLP) dependent enzymes are primordial enzymes that diversified in the last universal ancestor. Using the comparison of protein active site structures (CPASS) software and database, we show that the active site structures of PLP-dependent enzymes can be used to infer evolutionary relationships based on functional similarity. The enzymes successfully clustered together based on substrate specificity, function, and three-dimensional-fold. This study demonstrates the value of using active site structures for functional evolutionary analysis and the effectiveness of CPASS. © 2014 Wiley Periodicals, Inc.

Remaining Sites Verification Package for the 100-F-54 Animal Farm Pastures, Waste Site Reclassification Form 2008-015

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. M. Capron

2008-04-17

The 100-F-54 waste site, part of the 100-FR-2 Operable Unit, is the soil associated with the former pastures for holding domestic farm animals used in experimental toxicology studies. Evaluation of historical information resulted in identification of the experimental animal farm pastures as having potential residual soil contamination due to excrement from experimental animals. The 100-F-54 animal farm pastures confirmatory sampling results support a reclassification of this site to No Action. The current site conditions achieve the remedial action objectives and the corresponding remedial action goals established in the Remaining Sites ROD. The results of confirmatory sampling show that residual contaminantmore » concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.« less

Hetero-site-specific X-ray pump-probe spectroscopy for femtosecond intramolecular dynamics

DOE PAGES

Picón, A.; Lehmann, C. S.; Bostedt, C.; ...

2016-05-23

New capabilities at X-ray free-electron laser facilities allow the generation of two-colour femtosecond X-ray pulses, opening the possibility of performing ultrafast studies of X-ray-induced phenomena. Specifically, the experimental realization of hetero-site-specific X-ray-pump/X-ray-probe spectroscopy is of special interest, in which an X-ray pump pulse is absorbed at one site within a molecule and an X-ray probe pulse follows the X-ray-induced dynamics at another site within the same molecule. In this paper, we show experimental evidence of a hetero-site pump-probe signal. By using two-colour 10-fs X-ray pulses, we are able to observe the femtosecond time dependence for the formation of F ionsmore » during the fragmentation of XeF 2 molecules following X-ray absorption at the Xe site.« less

Geographic mosaics of species' association: a definition and an example driven by plant-insect phenological synchrony.

PubMed

Singer, Michael C; McBride, Carolyn S

2012-12-01

Spatial mosaics occur in both evolutionary and ecological properties of species' interactions. Studies of these patterns have facilitated description and prediction of evolutionary responses of interacting species to each other and to changing environments. We propose seeking complementary understanding of community assembly and dynamics by studying ecological and mechanistic properties of mosaics. We define "species' association mosaics" as deviations from a null model in which spatial variation in the extent to which particular species interact ecologically is explained solely by variation in their densities. In extreme deviations from the null, a focal species interacts exclusively with different partners at different sites despite similar abundances of potential partners. We investigate this type of mosaic involving the butterfly Euphydryas editha and its hosts, the perennial Pedicularis semibarbata (Psem) and the ephemeral annual Collinsia torreyi (Ctor). A reciprocal transplant experiment showed that the proximate, mechanistic driver of the mosaic was variation in butterfly oviposition preference: the identity of the preferred host species depended on the site of origin of the insects, not that of the plants. In contrast, the evolutionary driver was phenological asynchrony between the insects and Ctor. Censuses showed that larvae hatching from eggs laid on Ctor would have suffered significantly greater mortality from host senescence at five sites where Ctor was avoided than at two sites where it was used. These differences among sites in phenological synchrony were caused by variation in life span of Ctor. At sites where Ctor was avoided, natural selection on host preference was stabilizing because Ctor life span was too short to accommodate the development time of most larvae. At sites where Ctor was used, selection on preference was also stabilizing because larvae lacked physiological adaptation to feed on Psem. These reciprocal forces of stabilizing selection formed a mosaic maintaining spatial variation in insect host preference that was the proximate cause of the species-association mosaic. In the Discussion, we examine the extent to which our findings hindcast an observed anthropogenic host shift by E. editha from Psem to Ctor. This example shows that elucidation of species-association mosaics can facilitate understanding of community evolution and dynamics.

Effect of warming on larch trees in the Asian southern border of the boreal forest, Mongolia and China in the 20th century.

NASA Astrophysics Data System (ADS)

Lopez Caceres, Maximo Larry; Cho, Qiqin; Nobori, Yoshihiro; Takeda, Kazuo; Byambasuren, Mijidsuren; Zhang, Yandong; Sugimoto, Atsuko

2016-04-01

In recent decades air temperature (Ta) has been increasing steadily around the globe and it is reported that in the last 40 years Ta in Mongolia alone has increased by about 2.1 deg.C. The boreal region as a whole is expected to experience changes due to atmospheric drying, permafrost degradation, increases in the frequency of forest fires and other factors that will lead to a shift of the forest ecosystems northward. The southern border of the boreal forest distributes in northern Mongolia and northeast China, which as transition areas are more sensitive to changes. In a 500 km long south-north transect of larch forests extending in each of these two countries, larch forest sites were chosen (Larix sibirica in Mongolia and Larix gmeliini in China). Studies until now have used only tree-ring analysis to determined past and recent climate in Mongolia and China. However, isotope analysis has not been coupled with this analysis to give a wider overview of the environmental changes taking place in these regions. Therefore in this study tree core samples were collected for tree-ring and carbon isotope analysis to be coupled with available meteorological data. These data indicate that in the last four decades, the northernmost site of the selected transect has experienced the largest increase in Ta, but nevertheless the annual Ta in the southernmost site remained several degrees higher. On the other hand precipitation shows a very slight increase in the central and northernmost sites while an insignificant decrease is observed in the southernmost site. Tree-ring analysis shows that for most of the 20th century tree ring growth had lower inter-annual variability until the beginning of the 1970's but from then on the annual variability has increased. Unlike the results of the tree-ring analysis, the carbon isotope analysis revealed that until the 1970's the increases in the drying atmospheric conditions (higher temperature-no changes in rainfall) were not present but the steady increase in values from the 1980's clearly represented the drying effect, especially in the southernmost site. The differences in the carbon isotopic values reflect wetter conditions in the north than in the south but in general all sites are experiencing drier conditions than in previous decades. However the northern site showed more cyclic behavior with values increasing and decreasing in a decadal basis while the southern sites showed a steady increase from a mean value of -23.4 ‰ in the 1950's to a mean value of -21.0 ‰ in the first decade of the 21st century.

A search game model of the scatter hoarder's problem

PubMed Central

Alpern, Steve; Fokkink, Robbert; Lidbetter, Thomas; Clayton, Nicola S.

2012-01-01

Scatter hoarders are animals (e.g. squirrels) who cache food (nuts) over a number of sites for later collection. A certain minimum amount of food must be recovered, possibly after pilfering by another animal, in order to survive the winter. An optimal caching strategy is one that maximizes the survival probability, given worst case behaviour of the pilferer. We modify certain ‘accumulation games’ studied by Kikuta & Ruckle (2000 J. Optim. Theory Appl.) and Kikuta & Ruckle (2001 Naval Res. Logist.), which modelled the problem of optimal diversification of resources against catastrophic loss, to include the depth at which the food is hidden at each caching site. Optimal caching strategies can then be determined as equilibria in a new ‘caching game’. We show how the distribution of food over sites and the site-depths of the optimal caching varies with the animal's survival requirements and the amount of pilfering. We show that in some cases, ‘decoy nuts’ are required to be placed above other nuts that are buried further down at the same site. Methods from the field of search games are used. Some empirically observed behaviour can be shown to be optimal in our model. PMID:22012971

Occurrence, distribution, and seasonal variation of antibiotics in an artificial water source reservoir in the Yangtze River delta, East China.

PubMed

Cui, Changzheng; Han, Qi; Jiang, Lei; Ma, Lei; Jin, Lei; Zhang, Dong; Lin, Kuangfei; Zhang, Tianyang

2018-05-04

This study investigated the occurrence and variation of 11 antibiotics (including four sulfonamides (SAs), four fluoroquinolones (FQs), two tetracyclines (TCs), and one macrolide (ML)) and one SA synergist trimethoprim (TMP) in an artificial drinking water source reservoir in Yangtze River delta of East China. Water samples were collected each month from January to November in 2014 at the water inlet and outlet site of the reservoir. Sulfamethoxazole, sulfadiazine, and norfloxacin were detected with the high frequencies of 100, 92.31, and 97.85%, respectively. The total concentration showed the highest level in winter (229.14 ng/L) and the lowest one in summer (96.11 ng/L). FQs and TCs were the dominant species among all the antibiotics. The total amount of antibiotics detected in this reservoir showed a negative relationship with temperature (R 2  = 0.7565) in this area. From the inlet site to outlet site of this reservoir, all SAs as well as TMP showed decline trends in the four seasons, but other antibiotics including FQs, TCs, and MLs increased more or less in different seasons, especially for ciprofloxacin in winter (from 48.82 ng/L at inlet site to 80.36 ng/L at outlet site). Most antibiotics detected in this drinking water source reservoir had no direct health risk for human with different age groups (except ciprofloxacin for the group of 0-3 months), but still showed obvious ecological risk for algae and invertebrate. Among the three target organisms (algae, invertebrate, and fish), algae was the most sensitive for antibiotics, which was followed by invertebrate. Among the target antibiotics, sulfamethoxazole, ciprofloxacin, tetracycline, and oxytetracycline showed high ecological risk for algae (RQs > 1), and oxytetracycline also showed high risk for invertebrate (RQ = 1.34).

Increasing ammonia concentration trends in large regions of the USA derived from the NADP/AMoN network

NASA Astrophysics Data System (ADS)

Butler, T.; Vermeylen, F.; Lehmann, C. M.; Likens, G. E.; Puchalski, M.

2016-12-01

Data from bi-weekly passive samplers from 18 of the longest operating National Atmospheric Deposition Program's (NADP) Ammonia Monitoring Network (AMoN) sites (most operating from 2008 to 2015) show that concentrations of NH3 have been increasing (p-value < 0.0001) over large regions of the USA. This trend is occurring at a seasonal and annual level of aggregation. Using random coefficient models (RCM), the mean slope for the 18 sites combined shows an increase of NH3 concentration of +7% per year, with a 95% confidence interval (C.I.) from +5% to +9% per year. Travel blank corrected data using the same approach show increasing NH3 concentrations of +9% (95% C.I. +5% to +13%) per year. During a comparable period (2008-2014) NADP precipitation chemistry sites in the same regions show significant increasing (p-value = 0.0001) precipitation NH4+ concentrations trends for all sites combined of +5% (95% C.I. +3% to +7%) per year. Emissions inventory data for the study period show nearly constant rates of NH3 emissions, but large reductions in NOx and SO2 emissions. Seasonal air quality data from the Clean Air Status and Trends Network (CASTNET) sites in these regions show significant declines in atmospheric particulate SO42- and NH4+, and particulate NO3- plus HNO3 (total NO3-) during the same period. Less formation of acidic SO4 and NO3, due to reduced SO2 and NOx emissions, provide less substrate to interact with NH3 and form particulate ammonium species. Thus, concentrations of NH3 can increase in the atmosphere even if emissions remain constant. A likely result may be more localized deposition of NH3, as opposed to the more long-range transport and deposition of ammonium nitrate (NH4NO3) and sulfate (NH4)2SO4). Additionally, the spatial distribution of wet and dry acidic deposition will be impacted.

Seaweed temporal distribution in southeast coast of Peninsular Malaysia and isolation of endophytic fungi

NASA Astrophysics Data System (ADS)

Zainee, Nur Farah Ain; Ismail, Ahmad; Ibrahim, Nazlina; Ismail, Asmida

2018-04-01

Temporal study of seaweeds was carried out between on February 2015 and November 2015 at Kampung Jawa Darat and Kampung Sungai Buntu at Pengerang, Johor, Malaysia. The research objectives were to study the diversity of seaweed and to determine the presence of fungal endophyte in the seaweed. The diversity of seaweed in the sampling site was calculated by using quadrat with 25 meter line transect by 3 replication for each site. The specimen were identified and processed in laboratory and kept for reference in the Algae Herbarium, Universiti Kebangsaan Malaysia. The specimen for fungal endophyte isolation was collected randomly by choosing the complete thallus, transferred into sterile zip-lock plastic bag and kept in freezer until used. From this study, a total of 29 species have been successfully identified including 12 species of Chlorophyta, 2 species of Phaeophyta and 14 species of Rhodophyta. From February to November 2015, the number of species highly varied and a significant change in community structure was noted. Kampung Sungai Buntu shows the highest diversity throughout the study compared to Kampung Jawa Darat. Eighteen seaweed species were screened for the presence of fungal endophyte, Sargassum polycystum shows the highest number of fungal endophyte. This study documented the seaweed diversity in two sites at Pengerang, Johor that accommodates fungal endophytes.

Prediction of supratidal Zones as turtle nesting sites using remote sensing and geographic information system, a case study in Pacitan, Southern Java Sea

NASA Astrophysics Data System (ADS)

Darmawan, A.; Saputra, D. K.; Wiadnya, D. G. R.; Gusmida, A. M.

2018-04-01

Turtles, the most threatened coastal-marine fauna, are protected through both national and global regulations. However, many of their nesting sites have been degraded in the past years. Completing natal homing, adult females emerged at night to lay-down eggs in the upper intertidal and supra-tidal zone of sandy beach from where they hatched. This study explained coastal topology of beaches usually used for nesting sites, covering 117 km coastline at Pacitan Regency, Southern Java Sea. The shift in beach morphology through times was figured out based on Landsat 8 and Sentinel 2a satellite imagery and remote sensing (GIS methods). This was combined with in-situ data on current coastline features, slope, and tide variations. Results showed a typical sandy beach, called Taman Ria Beach, a long time identified as nesting site for Lepidochelys olivacea, locally named as Penyu Lekang. Also, there was approximatelly 3.49 ha of supratidal area predicted in Taman Ria Beach according this study

Effect of stretching on the ballistic conductance of Au nanocontacts in presence of CO: A density functional study

NASA Astrophysics Data System (ADS)

Sclauzero, Gabriele; Dal Corso, Andrea; Smogunov, Alexander

2012-04-01

CO adsorption on an Au monatomic chain is studied within density functional theory in nanocontact geometries as a function of the contact stretching. We compare the bridge and atop adsorption sites of CO, finding that the bridge site is energetically favored at all strains studied here. Atop adsorption gives rise to an almost complete suppression of the ballistic conductance of the nanocontact, while adsorption at the bridge site results in a conductance value close to 0.6G0, in agreement with previous experimental data. We show that only the bridge site can qualitatively account for the evolution of the conductance as a function of the contact stretching observed in the experimental conductance traces. The numerical discrepancy between the theoretical and experimental conductance slopes is rationalized through a simple model for the elastic response of the metallic leads. We also verify that our conductance values are not affected by the specific choice of the nanocontact geometry by comparing two different atomistic models for the tips.

Molting site fidelity accounts for colony elimination of the Formosan subterranean termites (Isoptera: Rhinotermitidae) by chitin synthesis inhibitor baits.

PubMed

Kakkar, G; Osbrink, W; Su, N-Y

2018-01-19

Site fidelity by molting termites in Formosan subterranean termite, Coptotermes formosanus Shiraki colonies is a new addition to our understanding of lower termites' behavior and biology. Our previous studies indicated that workers moved to the central nest to molt in the presence of eggs and reproductives. The current study showed that noviflumuron-affected workers also return to the central nest and died in the vicinity of reproductives and eggs. The aversion to the dead and decaying workers caused reproductives and brood to leave the original central nest site in a colony and refuge at newer sites every few days in response to newly dead workers near them. Because mortality was an event observed only in workers undergoing molting under the effect of noviflumuron- a CSI, the death of molting individuals was observed only around reproductives and brood. This study reveals a previously undiscovered behavior of molting termites and the mechanics behind a successful arsenal; noviflumuron baits used against subterranean termites.

Traditions in Spider Monkeys Are Biased towards the Social Domain

PubMed Central

Santorelli, Claire J.; Schaffner, Colleen M.; Campbell, Christina J.; Notman, Hugh; Pavelka, Mary S.; Weghorst, Jennifer A.; Aureli, Filippo

2011-01-01

Cross-site comparison studies of behavioral variation can provide evidence for traditions in wild species once ecological and genetic factors are excluded as causes for cross-site differences. These studies ensure behavior variants are considered within the context of a species' ecology and evolutionary adaptations. We examined wide-scale geographic variation in the behavior of spider monkeys (Ateles geoffroyi) across five long-term field sites in Central America using a well established ethnographic cross-site survey method. Spider monkeys possess a relatively rare social system with a high degree of fission-fusion dynamics, also typical of chimpanzees (Pan troglodytes) and humans (Homo sapiens). From the initial 62 behaviors surveyed 65% failed to meet the necessary criteria for traditions. The remaining 22 behaviors showed cross-site variation in occurrence ranging from absent through to customary, representing to our knowledge, the first documented cases of traditions in this taxon and only the second case of multiple traditions in a New World monkey species. Of the 22 behavioral variants recorded across all sites, on average 57% occurred in the social domain, 19% in food-related domains and 24% in other domains. This social bias contrasts with the food-related bias reported in great ape cross-site comparison studies and has implications for the evolution of human culture. No pattern of geographical radiation was found in relation to distance across sites. Our findings promote A. geoffroyi as a model species to investigate traditions with field and captive based experiments and emphasize the importance of the social domain for the study of animal traditions. PMID:21373196

Bioremediation of Southern Mediterranean oil polluted sites comes of age.

PubMed

Daffonchio, Daniele; Ferrer, Manuel; Mapelli, Francesca; Cherif, Ameur; Lafraya, Alvaro; Malkawi, Hanan I; Yakimov, Michail M; Abdel-Fattah, Yasser R; Blaghen, Mohamed; Golyshin, Peter N; Kalogerakis, Nicolas; Boon, Nico; Magagnini, Mirko; Fava, Fabio

2013-09-25

Mediterranean Sea is facing a very high risk of oil pollution due to the high number of oil extractive and refining sites along the basin coasts, and the intense maritime traffic of oil tankers. All the Mediterranean countries have adopted severe regulations for minimizing pollution events and bioremediation feasibility studies for the most urgent polluted sites are undergoing. However, the analysis of the scientific studies applying modern 'meta-omics' technologies that have been performed on marine oil pollution worldwide showed that the Southern Mediterranean side has been neglected by the international research. Most of the studies in the Mediterranean Sea have been done in polluted sites of the Northern side of the basin. Those of the Southern side are poorly studied, despite many of the Southern countries being major oil producers and exporters. The recently EU-funded research project ULIXES has as a major objective to increase the knowledge of the bioremediation potential of sites from the Southern Mediterranean countries. ULIXES is targeting four major polluted sites on the coastlines of Egypt, Jordan, Morocco and Tunisia, including seashore sands, lagoons, and oil refinery polluted sediments. The research is designed to unravel, categorize, catalogue, exploit and manage the diversity and ecology of microorganisms thriving in these polluted sites. Isolation of novel hydrocarbon degrading microbes and a series of state of the art 'meta-omics' technologies are the baseline tools for improving our knowledge on biodegradation capacities mediated by microbes under different environmental settings and for designing novel site-tailored bioremediation approaches. A network of twelve European and Southern Mediterranean partners is cooperating for plugging the existing gap of knowledge for the development of novel bioremediation processes targeting such poorly investigated polluted sites. Copyright © 2013 Elsevier B.V. All rights reserved.

Baseline characteristics of study sites and women enrolled in a three-arm cluster randomized controlled trial: PMTCT uptake and retention (pure) Malawi.

PubMed

van Lettow, Monique; Tweya, Hannock; Rosenberg, Nora E; Trapence, Clement; Kayoyo, Virginia; Kasende, Florence; Kaunda, Blessings; Hosseinipour, Mina C; Eliya, Michael; Cataldo, Fabian; Gugsa, Salem; Phiri, Sam

2017-07-11

Malawi introduced an ambitious public health program known as "Option B+" which provides all HIV-infected pregnant and breastfeeding women with lifelong combination antiretroviral therapy, regardless of WHO clinical stage or CD4 cell count. The PMTCT Uptake and REtention (PURE) study aimed at evaluating the effect of peer-support on care-seeking and retention in care. PURE Malawi was a three-arm cluster randomized controlled trial that compared facility-based and community-based models of peer support to standard of care under Option B+ strategy. Each arm was expected to enroll a minimum of 360 women with a total minimum sample size of 1080 participants. 21 sites (clusters) were selected for inclusion in the study. This paper describes the site selection, recruitment, enrollment process and baseline characteristics of study sites and women enrolled in the trial. Study implementation was managed by 3 partner organizations; each responsible for 7 study sites. The trial was conducted in the South East, South West, and Central West zones of Malawi, the zones where the implementing partners operate. Study sites included 2 district hospitals, 2 mission hospitals, 2 rural hospitals, 13 health centers and 1 private clinic. Enrollment occurred from November 2013 to November 2014, over a median period of 31 weeks (range 17-51) by site. A total of 1269 HIV-infected pregnant (1094) and breastfeeding (175) women, who were eligible to initiate ART under Option B+, were enrolled. Each site reached or surpassed the minimum sample size. Comparing the number of women enrolled versus antenatal cohort reports, sites recruited a median of 90% (IQR 75-100) of eligible reported women. In the majority of sites the ratio of pregnant and lactating women enrolled in the study was similar to the ratio of reported pregnant and lactating women starting ART in the same sites. The median age of all women was 27 (IQR 22-31) years. All women have ≥20 months of possible follow-up time; 96% ≥ 2 years (24-32 months). The PURE Malawi study showed that 3 implementing partner organizations could successfully recruit a complex cohort of pregnant and lactating women across 3 geographical zones in Malawi within a reasonable timeline. This study is registered at clinicaltrials.gov - ID Number NCT02005835 . Registered 4 December, 2013.

Monte Carlo performance studies for the site selection of the Cherenkov Telescope Array

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hassan, T.; Arrabito, L.; Bernlöhr, K.

The Cherenkov Telescope Array (CTA) represents the next generation of ground-based instruments for very-high-energy (VHE) gamma-ray astronomy, aimed at improving on the sensitivity of current-generation experiments by an order of magnitude and providing coverage over four decades of energy. The current CTA design consists of two arrays of tens of imaging atmospheric Cherenkov Telescopes, comprising Small, Medium and Large-Sized Telescopes, with one array located in each of the Northern and Southern Hemispheres. To study the effect of the site choice on the overall CTA performance and support the site evaluation process, detailed Monte Carlo simulations have been performed. These resultsmore » show the impact of different site-related attributes such as altitude, night-sky background and local geomagnetic field on CTA performance for the observation of VHE gamma rays.« less

Monte Carlo performance studies for the site selection of the Cherenkov Telescope Array

DOE PAGES

Hassan, T.; Arrabito, L.; Bernlöhr, K.; ...

2017-05-03

The Cherenkov Telescope Array (CTA) represents the next generation of ground-based instruments for very-high-energy (VHE) gamma-ray astronomy, aimed at improving on the sensitivity of current-generation experiments by an order of magnitude and providing coverage over four decades of energy. The current CTA design consists of two arrays of tens of imaging atmospheric Cherenkov Telescopes, comprising Small, Medium and Large-Sized Telescopes, with one array located in each of the Northern and Southern Hemispheres. To study the effect of the site choice on the overall CTA performance and support the site evaluation process, detailed Monte Carlo simulations have been performed. These resultsmore » show the impact of different site-related attributes such as altitude, night-sky background and local geomagnetic field on CTA performance for the observation of VHE gamma rays.« less

Channel erosion surveys along the TAPS route, Alaska, 1977

USGS Publications Warehouse

Loeffler, Robert M.; Childers, Joseph M.

1977-01-01

Channel surveys were made along the trans-Alaska pipeline system (TAPS) route during 1977 at the same 28 sites that were studied in 1976. In addition, a new site at pipeline mile 22 near Deadhorse (alignment No 134) along the Sagavanirktok River was put under surveillance. Except for changes wrought by the completion of construction, most of the sites showed very little change. Significant events include virtual completion of all construction activities along the pipeline, the pipeline startup , and the breakup flood along the Sagavanirktok River which breached many river-training structures. In general, 1977 saw heavy flooding on streams draining the north and south slopes of the Brooks Range and only moderate flooding on streams further south. Aerial photogrammetric surveys were used again in 1977 on the same seven sites as in 1976. Results document the applicability of the method for channel erosion studies. (Woodard-USGS)

Carbon diffusion in bulk hcp zirconium: A multi-scale approach

NASA Astrophysics Data System (ADS)

Xu, Y.; Roques, J.; Domain, C.; Simoni, E.

2016-05-01

In the framework of the geological repository of the used fuel claddings of pressurized water reactor, carbon behavior in bulk zirconium is studied by periodic Density Functional Theory calculations. The C interstitial sites were investigated and it was found that there are two possible carbon interstitial sites: a distorted basal tetragonal site and an octahedral site. There are four types of possible atomic jumps between them. After calculating the migration energies, the attempt frequencies and the jump probabilities for each possible migration path, kinetic Monte Carlo (KMC) simulations were performed to simulate carbon diffusion at the macroscopic scale. The results show that carbon diffusion in pure Zr bulk is extremely limited at the storage temperature (50 °C). Since there are defects in Zr bulk, in a second step, the effect of atomic vacancy was studied and it was proved that vacancies cannot increase carbon diffusion.

A Qualitative Evidence of the Breeding Sites of Anopheles arabiensis Patton (Diptera: Culicidae) in and Around Kassala Town, Eastern Sudan

PubMed Central

Hamza, Asma Mahmoud; El Rayah, El Amin

2016-01-01

Anopheles arabiensis Patton (Diptera: Culicidae) is considered the most efficient malaria vector in eastern Sudan. This study aims to characterize the breeding sites of An. arabiensis throughout the year in and around Kassala town, eastern Sudan. Diverse larval habitat types were visited and characterized based on the habitat type and chemical composition. Mosquito larvae were found in many diverse habitats. During the rainy season, rain pools and water bodies created by the seasonal Gash River serve as the main breeding sites. In the dry season, irrigation canals, seepage from water pipes, neglected wells, artificial containers, and man-made ditches serve as the main breeding sites. Breeding water showed a pH of 7.9 and a low concentration of the total dissolved salts. The results of this study may be considered in planning and implementing larval control programs in the area. PMID:27547039

Evaluating meteorological data from weather stations, and from satellites and global models for a multi-site epidemiological study.

PubMed

Colston, Josh M; Ahmed, Tahmeed; Mahopo, Cloupas; Kang, Gagandeep; Kosek, Margaret; de Sousa Junior, Francisco; Shrestha, Prakash Sunder; Svensen, Erling; Turab, Ali; Zaitchik, Benjamin

2018-04-21

Longitudinal and time series analyses are needed to characterize the associations between hydrometeorological parameters and health outcomes. Earth Observation (EO) climate data products derived from satellites and global model-based reanalysis have the potential to be used as surrogates in situations and locations where weather-station based observations are inadequate or incomplete. However, these products often lack direct evaluation at specific sites of epidemiological interest. Standard evaluation metrics of correlation, agreement, bias and error were applied to a set of ten hydrometeorological variables extracted from two quasi-global, commonly used climate data products - the Global Land Data Assimilation System (GLDAS) and Climate Hazards Group InfraRed Precipitation with Stations (CHIRPS) - to evaluate their performance relative to weather-station derived estimates at the specific geographic locations of the eight sites in a multi-site cohort study. These metrics were calculated for both daily estimates and 7-day averages and for a rotavirus-peak-season subset. Then the variables from the two sources were each used as predictors in longitudinal regression models to test their association with rotavirus infection in the cohort after adjusting for covariates. The availability and completeness of station-based validation data varied depending on the variable and study site. The performance of the two gridded climate models varied considerably within the same location and for the same variable across locations, according to different evaluation criteria and for the peak-season compared to the full dataset in ways that showed no obvious pattern. They also differed in the statistical significance of their association with the rotavirus outcome. For some variables, the station-based records showed a strong association while the EO-derived estimates showed none, while for others, the opposite was true. Researchers wishing to utilize publicly available climate data - whether EO-derived or station based - are advised to recognize their specific limitations both in the analysis and the interpretation of the results. Epidemiologists engaged in prospective research into environmentally driven diseases should install their own weather monitoring stations at their study sites whenever possible, in order to circumvent the constraints of choosing between distant or incomplete station data or unverified EO estimates. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Studies on the cellular localization of spinal cord substance P receptors.

PubMed

Helke, C J; Charlton, C G; Wiley, R G

1986-10-01

Substance P-immunoreactivity and specific substance P binding sites are present in the spinal cord. Receptor autoradiography showed the discrete localization of substance P binding sites in both sensory and motor regions of the spinal cord and functional studies suggested an important role for substance P receptor activation in autonomic outflow, nociception, respiration and somatic motor function. In the current studies, we investigated the cellular localization of substance P binding sites in rat spinal cord using light microscopic autoradiography combined with several lesioning techniques. Unilateral injections of the suicide transport agent, ricin, into the superior cervical ganglion reduced substance P binding and cholinesterase-stained preganglionic sympathetic neurons in the intermediolateral cell column. However, unilateral electrolytic lesions of ventral medullary substance P neurons which project to the intermediolateral cell column did not alter the density of substance P binding in the intermediolateral cell column. Likewise, 6-hydroxydopamine and 5,7-dihydroxytryptamine, which destroy noradrenergic and serotonergic nerve terminals, did not reduce the substance P binding in the intermediolateral cell column. It appears, therefore, that the substance P binding sites are located postsynaptically on preganglionic sympathetic neurons rather than presynaptically on substance P-immunoreactive processes (i.e. as autoreceptors) or on monoamine nerve terminals. Unilateral injections of ricin into the phrenic nerve resulted in the unilateral destruction of phrenic motor neurons in the cervical spinal cord and caused a marked reduction in the substance P binding in the nucleus. Likewise, sciatic nerve injections of ricin caused a loss of associated motor neurons in the lateral portion of the ventral horn of the lumbar spinal cord and a reduction in the substance P binding. Sciatic nerve injections of ricin also destroyed afferent nerves of the associated dorsal root ganglia and increased the density of substance P binding in the dorsal horn. Capsaicin, which destroys small diameter primary sensory neurons, similarly increased the substance P binding in the dorsal horn. These studies show that the cellular localization of substance P binding sites can be determined by analysis of changes in substance P binding to discrete regions of spinal cord after selective lesions of specific groups of neurons. The data show the presence of substance P binding sites on preganglionic sympathetic neurons in the intermediolateral cell column and on somatic motor neurons in the ventral horn, including the phrenic motor nucleus.(ABSTRACT TRUNCATED AT 400 WORDS)