Density Resolution Artifacts Encountered When Scanning Infant Heads With X-Ray Computed Tomography (CT)

NASA Astrophysics Data System (ADS)

Thompson, Joseph R.; M oore, Robert J.; Hinshaw, David B.; Hasso, Anton N.

1982-12-01

Density resolution the accuracy of CT numbers) is generally recognized by radiologists w'ao interpret Children's, CT to be very poor. A CT scanning phantom was made. in order to document the brain attenuation inaccuracies which do occur and also to derive normal brain attenuation values for varying sized heads, given. the skull diameters and thicknesses. In scanning' this phantom, other factors, some of equal importance, to small head size, were found to affect the Hounsfield numbers of brain. The phantom was scanned in order to determine the magnitude of these specific factors, using the GE 8800 model scanner. After head size (412 to 25, H), the variables of the head support (up to 15 H) and centering within the field of view (6-23 H) were of similar importance, for small heads. Kilovoltage, software, and machine drift were less, important, although only kVp settings, of 105 and 120 were employed. Manufacturers may improve CT number accuracy if they recognize the relative, magnitude of the various factors which alter measured attenuation.

Grainsize evolution and differential comminution in an experimental regolith

NASA Technical Reports Server (NTRS)

Horz, F.; Cintala, M.; See, T.

1984-01-01

The comminution of planetary surfaces by exposure to continuous meteorite bombardment was simulated by impacting the same fragmental gabbro target 200 times. The role of comminution and in situ gardening of planetary regoliths was addressed. Mean grain size continuously decreased with increasing shot number. Initially it decreased linearly with accumulated energy, but at some stage comminution efficiency started to decrease gradually. Point counting techniques, aided by the electron microprobe for mineral identification, were performed on a number of comminution products. Bulk chemical analyses of specific grain size fractions were also carried out. The finest sizes ( 10 microns) display generally the strongest enrichment/depletion factors. Similar, if not exactly identical, trends are reported from lunar soils. It is, therefore, not necessarily correct to explain the chemical characteristics of various grain sizes via different admixtures of materials from distant source terrains. Differential comminution of local source rocks may be the dominating factor.

Two cell-counting factors regulate the aggregate size of the cellular slime mold Dictyostelium discoideum.

PubMed

Okuwa, T; Katayama, T; Takano, A; Kodaira, K; Yasukawa, H

2001-12-01

Countin, a cell-counting factor in Dictyostelium discoideum, is considered to limit the maximum size of the multicellular structure, because a countin null strain forms a huge fruiting body compared to that of the wild-type. A novel gene, countin2, that is highly homologous to countin (40% identity in amino acid sequence) was identified in the D. discoideum genome. The countin2 null strain formed a 1.7-fold higher number of the aggregates, resulting in smaller fruiting bodies compared with those of wild-type cells. Thus, the Countin2 protein is thought to limit the minimum size of the multicellular structure. The size and number of aggregates formed by a mixture of countin null and countin2 null strains were the same as those of the wild-type. These findings demonstrate that a combination of Countin and Countin2 proteins determines the appropriate size of the multicellular structure of D. discoideum.

The Size Distribution of Atmospheric Aerosols at Kosan, Korea during ACE-Asia: Changes due to Dust Input and Scavenging by Precipitation

NASA Astrophysics Data System (ADS)

Jung, C.; Kim, J.; Choi, B.; Brechtel, F. J.; Buzorius, G.; Oh, S.

2001-12-01

Measurements of size-resolved aerosol number concentrations were made at the Kosan supersite in Korea during the ACE-Asia intensive observation period. An optical particle counter (OPC) was used for measurements in the 0.3-25.0 micrometer diameter size range every ten minutes while a scanning electrical mobility spectrometer (SEMS) was used for smaller particles. A comparison of size distributions between dust and non-dust input periods and times with and without precipitation has been performed. During dust events, the number and volume concentrations of large particles (>1.35 micrometer) increased by factors of 10 and 1000, respectively. Also, a dominant number mode diameter between 2.23-3.67 micrometer was observed during dust events. The number concentrations of smaller particles observed by the OPC (0.3-1 micrometer) and SEMS (0.005-0.6 micrometer) were relatively smaller during dust events, consistent with previous studies and the effect of coagulation processes (Zaizen et al., 1995; Chun et al., 2001). During precipitation events, coarse mode particles (>1 micrometer) were scavenged more efficiently than smaller particles. This result suggests that large particles are efficiently scavenged by impaction with raindrops. In contrast, relatively minor reductions in the number concentrations of small particles (0.3-1 micrometer) were observed during precipitation events. SEMS results during one precipitation event indicate factor of three reductions in total number and area concentrations for particle sizes below the detection limit of the OPC. Results from theoretical analyses of scavenging rates as a function of particle size during precipitation events will be presented and compared to values derived from observed size distributions. References Chun, Y., Kim, J., Choi, J. C., Boo, K. O., Oh, S. N., and Lee, M. (2001). Characteristic number size distribution of aerosol during Asian dust period in Korea, Atmospheric Environment, 35, 2715-2721. Zaizen, Y., Ikegami, M., Okada, K., and Makino, Y. (1995). Aerosol concentration observed at Zhangye in China, J. Meteorological Society in Japan, 73, 891-897.

Effects of forest fragmentation on the beetle assemblage at the relict forest of Fray Jorge, Chile.

PubMed

Barbosa, Olga; Marquet, Pablo A

2002-07-01

Habitat fragmentation is recognized as one of the main factors associated with species extinction and is particularly acute in South American forest habitats. In this study, we examined the effects of forest fragmentation on the beetle assemblage at the relict temperate forest of Fray Jorge (Chile). We evaluated the following hypotheses: (1) there is a strong edge effect, so that the number of beetle species and individuals increases away from the edge, towards the inner part of each fragment, (2) this pattern should be apparent in the larger fragments but not in the smaller ones, where edge effects are expected to be stronger, and (3) there should be a significant interaction between number of species/individuals found inside and outside fragments (i.e., in the matrix) and season, because of an increase in aridity and water stress during austral summer months. We found that the relationship between the number of individuals and number of species vs distance from the matrix towards the forest interior was affected by fragment size and season. In general, both number of species and individuals tended to increase from the matrix towards the forest edge and then either decrease, increase or maintain a constant level, depending on fragment size and season. The result of an ANOVA analysis, which used season, size, and position (inside vs outside fragments) as factors and number of individuals as the response variable, showed a significant effect of fragment size, position, and season and a significant interaction between fragment size and season, season and position, and size and position. ANOVA analysis using number of species as the response variable showed that area, season, and position all had significant effects. The results also showed a significant interaction between size and season and between season and position. Our results emphasize the existence of strong fragment-size and seasonal effects modulating both the response of beetles to fragmentation and their abundance and distribution in temperate areas. Thus, seasonal dynamic effects can be of paramount importance to demonstrate and understand the effect of habitat fragmentation upon arthropod assemblages in temperate areas.

Prediction of earthquake-triggered landslide event sizes

NASA Astrophysics Data System (ADS)

Braun, Anika; Havenith, Hans-Balder; Schlögel, Romy

2016-04-01

Seismically induced landslides are a major environmental effect of earthquakes, which may significantly contribute to related losses. Moreover, in paleoseismology landslide event sizes are an important proxy for the estimation of the intensity and magnitude of past earthquakes and thus allowing us to improve seismic hazard assessment over longer terms. Not only earthquake intensity, but also factors such as the fault characteristics, topography, climatic conditions and the geological environment have a major impact on the intensity and spatial distribution of earthquake induced landslides. We present here a review of factors contributing to earthquake triggered slope failures based on an "event-by-event" classification approach. The objective of this analysis is to enable the short-term prediction of earthquake triggered landslide event sizes in terms of numbers and size of the affected area right after an earthquake event occurred. Five main factors, 'Intensity', 'Fault', 'Topographic energy', 'Climatic conditions' and 'Surface geology' were used to establish a relationship to the number and spatial extend of landslides triggered by an earthquake. The relative weight of these factors was extracted from published data for numerous past earthquakes; topographic inputs were checked in Google Earth and through geographic information systems. Based on well-documented recent earthquakes (e.g. Haiti 2010, Wenchuan 2008) and on older events for which reliable extensive information was available (e.g. Northridge 1994, Loma Prieta 1989, Guatemala 1976, Peru 1970) the combination and relative weight of the factors was calibrated. The calibrated factor combination was then applied to more than 20 earthquake events for which landslide distribution characteristics could be cross-checked. One of our main findings is that the 'Fault' factor, which is based on characteristics of the fault, the surface rupture and its location with respect to mountain areas, has the most important contribution for the prediction of the number (and concentration) of induced landslides. This, for instance, partly explains why the Wenchuan 2008 earthquake triggered far more landslides than the Nepal 2015 earthquake. Moreover, according to our prediction the most severe earthquake-triggered landslide event would have been the Assam 1950 earthquake (India), followed by the 2008 Wenchuan earthquake. Regarding the overall performance of our prediction method it can be seen that the number of landslides is overestimated for a series of earthquakes, while the size of the affected area is often underestimated. Especially for older events the incompleteness of the published catalogues can partly explain the overestimation of the landslide numbers. The underestimation of the affected area however is real and must be attributed to particular remote effects of earthquakes.

Particle and gaseous emissions from commercial aircraft at each stage of the landing and takeoff cycle.

PubMed

Mazaheri, M; Johnson, G R; Morawska, L

2009-01-15

A novel technique was used to measure emission factors for commonly used commercial aircraft including a range of Boeing and Airbus airframes under real world conditions. Engine exhaust emission factors for particles in terms of particle number and mass (PM2.5), along with those for CO2 and NOx, were measured for over 280 individual aircraft during the various modes of landing/takeoff (LTO) cycle. Results from this study show that particle number, and NOx emission factors are dependent on aircraft engine thrust level. Minimum and maximum emissions factors for particle number, PM2.5, and NOx emissions were found to be in the range of 4.16 x 10(15)-5.42 x 10(16) kg(-1), 0.03-0.72 g.kg(-1), and 3.25-37.94 g.kg(-1), respectively, for all measured airframes and LTO cycle modes. Number size distributions of emitted particles for the naturally diluted aircraft plumes in each mode of LTO cycle showed that particles were predominantly in the range of 4-100 nm in diameter in all cases. In general, size distributions exhibit similar modality during all phases of the LTO cycle. A very distinct nucleation mode was observed in all particle size distributions, except for taxiing and landing of A320 aircraft. Accumulation modes were also observed in all particle size distributions. Analysis of aircraft engine emissions during LTO cycle showed that aircraft thrust level is considerably higher during taxiing than idling suggesting that International Civil Aviation Organization (ICAO) standards need to be modified as the thrust levels for taxi and idle are considered to be the same (7% of total thrust) (Environmental Protection, Annex 16, Vol. II, Aircraft Engine Emissions, 2nd ed.; ICAO--International Civil Aviation Organization: Montreal, 1993).

Research groups: How big should they be?

PubMed

Cook, Isabelle; Grange, Sam; Eyre-Walker, Adam

2015-01-01

Understanding the relationship between scientific productivity and research group size is important for deciding how science should be funded. We have investigated the relationship between these variables in the life sciences in the United Kingdom using data from 398 principle investigators (PIs). We show that three measures of productivity, the number of publications, the impact factor of the journals in which papers are published and the number of citations, are all positively correlated to group size, although they all show a pattern of diminishing returns-doubling group size leads to less than a doubling in productivity. The relationships for the impact factor and the number of citations are extremely weak. Our analyses suggest that an increase in productivity will be achieved by funding more PIs with small research groups, unless the cost of employing post-docs and PhD students is less than 20% the cost of a PI. We also provide evidence that post-docs are more productive than PhD students both in terms of the number of papers they produce and where those papers are published.

Exploratory graph analysis: A new approach for estimating the number of dimensions in psychological research

PubMed Central

Golino, Hudson F.; Epskamp, Sacha

2017-01-01

The estimation of the correct number of dimensions is a long-standing problem in psychometrics. Several methods have been proposed, such as parallel analysis (PA), Kaiser-Guttman’s eigenvalue-greater-than-one rule, multiple average partial procedure (MAP), the maximum-likelihood approaches that use fit indexes as BIC and EBIC and the less used and studied approach called very simple structure (VSS). In the present paper a new approach to estimate the number of dimensions will be introduced and compared via simulation to the traditional techniques pointed above. The approach proposed in the current paper is called exploratory graph analysis (EGA), since it is based on the graphical lasso with the regularization parameter specified using EBIC. The number of dimensions is verified using the walktrap, a random walk algorithm used to identify communities in networks. In total, 32,000 data sets were simulated to fit known factor structures, with the data sets varying across different criteria: number of factors (2 and 4), number of items (5 and 10), sample size (100, 500, 1000 and 5000) and correlation between factors (orthogonal, .20, .50 and .70), resulting in 64 different conditions. For each condition, 500 data sets were simulated using lavaan. The result shows that the EGA performs comparable to parallel analysis, EBIC, eBIC and to Kaiser-Guttman rule in a number of situations, especially when the number of factors was two. However, EGA was the only technique able to correctly estimate the number of dimensions in the four-factor structure when the correlation between factors were .7, showing an accuracy of 100% for a sample size of 5,000 observations. Finally, the EGA was used to estimate the number of factors in a real dataset, in order to compare its performance with the other six techniques tested in the simulation study. PMID:28594839

Exploratory graph analysis: A new approach for estimating the number of dimensions in psychological research.

PubMed

Golino, Hudson F; Epskamp, Sacha

2017-01-01

The estimation of the correct number of dimensions is a long-standing problem in psychometrics. Several methods have been proposed, such as parallel analysis (PA), Kaiser-Guttman's eigenvalue-greater-than-one rule, multiple average partial procedure (MAP), the maximum-likelihood approaches that use fit indexes as BIC and EBIC and the less used and studied approach called very simple structure (VSS). In the present paper a new approach to estimate the number of dimensions will be introduced and compared via simulation to the traditional techniques pointed above. The approach proposed in the current paper is called exploratory graph analysis (EGA), since it is based on the graphical lasso with the regularization parameter specified using EBIC. The number of dimensions is verified using the walktrap, a random walk algorithm used to identify communities in networks. In total, 32,000 data sets were simulated to fit known factor structures, with the data sets varying across different criteria: number of factors (2 and 4), number of items (5 and 10), sample size (100, 500, 1000 and 5000) and correlation between factors (orthogonal, .20, .50 and .70), resulting in 64 different conditions. For each condition, 500 data sets were simulated using lavaan. The result shows that the EGA performs comparable to parallel analysis, EBIC, eBIC and to Kaiser-Guttman rule in a number of situations, especially when the number of factors was two. However, EGA was the only technique able to correctly estimate the number of dimensions in the four-factor structure when the correlation between factors were .7, showing an accuracy of 100% for a sample size of 5,000 observations. Finally, the EGA was used to estimate the number of factors in a real dataset, in order to compare its performance with the other six techniques tested in the simulation study.

Monthly motor fuel reported by states : March 2006

DOT National Transportation Integrated Search

1995-02-01

Truck size and weight regulations affect the numbers, physical characteristics, load characteristics, and operating capabilities of trucks on highways. These factors affect highway capacity (expressed in terms of the total number of vehicles a facili...

Dissociation of somatic growth from segmentation drives gigantism in snakes.

PubMed

Head, Jason J; David Polly, P

2007-06-22

Body size is significantly correlated with number of vertebrae (pleomerism) in multiple vertebrate lineages, indicating that change in number of body segments produced during somitogenesis is an important factor in evolutionary change in body size, but the role of segmentation in the evolution of extreme sizes, including gigantism, has not been examined. We explored the relationship between body size and vertebral count in basal snakes that exhibit gigantism. Boids, pythonids and the typhlopid genera, Typhlops and Rhinotyphlops, possess a positive relationship between body size and vertebral count, confirming the importance of pleomerism; however, giant taxa possessed fewer than expected vertebrae, indicating that a separate process underlies the evolution of gigantism in snakes. The lack of correlation between body size and vertebral number in giant taxa demonstrates dissociation of segment production in early development from somatic growth during maturation, indicating that gigantism is achieved by modifying development at a different stage from that normally selected for changes in body size.

Genetic architecture of autosome-mediated hybrid male sterility in Drosophila.

PubMed

Marín, I

1996-04-01

Several estimators have been developed for assessing the number of sterility factors in a chromosome based on the sizes of fertile and sterile introgressed fragments. Assuming that two factors are required for producing sterility, simulations show that one of these, twice the inverse of the relative size of the largest fertile fragment, provides good average approximations when as few as five fertile fragments are analyzed. The estimators have been used for deducing the number of factors from previous data on several pairs of species. A particular result contrasts with the authors' interpretations: instead of the high number of sterility factors suggested, only a few per autosome are estimated in both reciprocal crosses involving Drosophila buzzatii and D. koepferae. It has been possible to map these factors, between three and six per chromosome, in the autosomes 3 and 4 of these species. Out of 203 introgressions of different fragments or combinations of fragments, the outcome of at least 192 is explained by the mapped zones. These results suggest that autosome-mediated sterility in the male hybrids of these species is mediated by a few epistatic factors, similarly to X-mediated sterility in the hybrids of other Drosophila species.

Simultaneous measurements of particle number size distributions at ground level and 260 m on a meteorological tower in urban Beijing, China

NASA Astrophysics Data System (ADS)

Du, Wei; Zhao, Jian; Wang, Yuying; Zhang, Yingjie; Wang, Qingqing; Xu, Weiqi; Chen, Chen; Han, Tingting; Zhang, Fang; Li, Zhanqing; Fu, Pingqing; Li, Jie; Wang, Zifa; Sun, Yele

2017-06-01

Despite extensive studies into the characterization of particle number size distributions at ground level, real-time measurements above the urban canopy in the megacity of Beijing have never been performed to date. Here we conducted the first simultaneous measurements of size-resolved particle number concentrations at ground level and 260 m in urban Beijing from 22 August to 30 September. Our results showed overall similar temporal variations in number size distributions between ground level and 260 m, yet periods with significant differences were also observed. Particularly, accumulation-mode particles were highly correlated (r2 = 0. 85) at the two heights, while Aitken-mode particles presented more differences. Detailed analysis suggests that the vertical differences in number concentrations strongly depended on particle size, and particles with a mobility diameter between 100 and 200 nm generally showed higher concentrations at higher altitudes. Particle growth rates and condensation sinks were also calculated, which were 3.2 and 3.6 nm h-1, and 2.8 × 10-2 and 2.9 × 10-2 s-1, at ground level and 260 m, respectively. By linking particle growth with aerosol composition, we found that organics appeared to play an important role in the early stage of the growth (09:00-12:00 LT) while sulfate was also important during the later period. Positive matrix factorization of size-resolved number concentrations identified three common sources at ground level and 260 m, including a factor associated with new particle formation and growth events (NPEs), and two secondary factors that represent photochemical processing and regional transport. Cooking emission was found to have a large contribution to small particles and showed much higher concentration at ground level than 260 m in the evening. These results imply that investigation of NPEs at ground level in megacities needs to consider the influences of local cooking emissions. The impacts of regional emission controls on particle number concentrations were also illustrated. Our results showed that regional emission controls have a dominant impact on accumulation-mode particles by decreasing gas precursors and particulate matter loadings, and hence suppressing particle growth. In contrast, the influences on Aitken particles were much smaller due to the enhanced new particle formation (NPF) events.

Clinical value and indication for the dissection of lymph nodes posterior to the right recurrent laryngeal nerve in papillary thyroid carcinoma.

PubMed

Luo, Ding-Cun; Xu, Xiao-Cheng; Ding, Jin-Wang; Zhang, Yu; Peng, You; Pan, Gang; Zhang, Wo

2017-10-03

Lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN) are common sites of nodal recurrence after the resection of papillary thyroid carcinoma (PTC). However, the indication for LN-prRLN dissection remains debatable. We therefore studied the relationships between LN-prRLN metastasis and the clinicopathological characteristics in 306 patients with right or bilateral PTC who underwent LN-prRLN dissection. We found that LN-prRLN metastasis occurred in 16.67% of PTC and was associated with a number of the clinicopathological features. The receiver-operator characteristic (ROC) analysis showed that the areas under the ROC curves for the prediction of LN-prRLN metastasis by the risk factors age < 35.5 years, right tumor size > 0.85 cm, lymph node (right cervical central VI-1) number > 1.5, metastatic lymph node (right cervical central VI-1) size > 0.45 cm, and lymph node number in the right cervical lateral compartment > 0.5 were 0.601, 0.815, 0.813, 0.725, and 0.743, respectively. In conclusion, the risk factors for LN-prRLN metastasis in patients suffering right thyroid lobe or bilateral PTC include age ≤ 35.5 years, right tumor size ≥ 0.85 cm, capsular invasion, metastatic lymph node (right cervical central VI-1) number ≥ 2, metastatic lymph node (right cervical central VI-1) size ≥ 0.45 cm, and metastatic lymph node number in the right cervical lateral compartment ≥ 1. In patients whose risk factors can be identified pre-operatively or intraoperatively, the dissection of LN-pr-RLN should be considered during right cervical central compartment dissection.

Performance of a Line Loss Correction Method for Gas Turbine Emission Measurements

NASA Astrophysics Data System (ADS)

Hagen, D. E.; Whitefield, P. D.; Lobo, P.

2015-12-01

International concern for the environmental impact of jet engine exhaust emissions in the atmosphere has led to increased attention on gas turbine engine emission testing. The Society of Automotive Engineers Aircraft Exhaust Emissions Measurement Committee (E-31) has published an Aerospace Information Report (AIR) 6241 detailing the sampling system for the measurement of non-volatile particulate matter from aircraft engines, and is developing an Aerospace Recommended Practice (ARP) for methodology and system specification. The Missouri University of Science and Technology (MST) Center for Excellence for Aerospace Particulate Emissions Reduction Research has led numerous jet engine exhaust sampling campaigns to characterize emissions at different locations in the expanding exhaust plume. Particle loss, due to various mechanisms, occurs in the sampling train that transports the exhaust sample from the engine exit plane to the measurement instruments. To account for the losses, both the size dependent penetration functions and the size distribution of the emitted particles need to be known. However in the proposed ARP, particle number and mass are measured, but size is not. Here we present a methodology to generate number and mass correction factors for line loss, without using direct size measurement. A lognormal size distribution is used to represent the exhaust aerosol at the engine exit plane and is defined by the measured number and mass at the downstream end of the sample train. The performance of this line loss correction is compared to corrections based on direct size measurements using data taken by MST during numerous engine test campaigns. The experimental uncertainty in these correction factors is estimated. Average differences between the line loss correction method and size based corrections are found to be on the order of 10% for number and 2.5% for mass.

[Factors associated with malignancy in gallbladder polyps without gallbladder stone].

PubMed

Lee, Jae Seung; Lee, Kyu Taek; Jung, Jae Hong; Ok, Sung Wook; Choi, Sung Chul; Lee, Kwang Hyuck; Lee, Jong Kyun; Heo, Jin Seok; Choi, Seong Ho; Rhee, Jong Chul

2008-08-01

The purpose of this study was to find the factors predicting the neoplastic polyp of gallbladder and analyze the size criteria associated with malignancy. A total of 354 subjects with gallbladder polyps confirmed by tissue pathology were included for the analysis. The clinical and radiological features of the polyps were compared between the two groups (neoplastic vs. non-neoplastic) and in the three groups (non-neoplastic vs. adenoma vs. adenocarcinoma). The independent factors associated with malignancy were studied. Of 354 patients, non-neoplastic polyps were observed in 229 (64.7%) patents, adenoma in 85 (24.0%) and adenocarcinoma in 40 (11.3%). The mean diameter of non-neoplastic polyp, adenoma, and adenocarcinoma were 11.3+/-2.8 mm, 16.0+/-7.2 mm, and 27.0+/-8.9 mm, respectively. The mean age of patients with non-neoplastic polyp, adenoma, and adenocarcinoma were 44.8+/-11.3, 49.9+/-12.5, and 60.8+/-9.6, respectively. Age, size of polyp, number of polyp, presence of diabetes, and presence of symptom showed statistically significant difference between the neoplastic polyp and non-neoplastic polyp groups. But only age, size of polyp, number of polyp were statistically independent factors associated with neoplastic polyp (p<0.05). To predict the neoplastic polyp, sensitivity was 94.4%, but specificity was 18.3% on the basis of 10 mm criteria. whereas sensitivity and specificity was 76.0% and 55.5% on the 12 mm-criteria. On the basis of our analysis, the size of polyp is the most important factor to predict the malignancy. In the 10 mm criteria, sensitivity is satisfactory but specificity is very low. Therefore 10 mm size should not be considered to be the absolute size-criterion for surgery.

Bipartite networks improve understanding of effects of waterbody size and angling method on angler–fish interactions

USGS Publications Warehouse

Chizinski, Christopher J.; Martin, Dustin R.; Shizuka, Daizaburo; Pope, Kevin L.

2018-01-01

Networks used to study interactions could provide insights to fisheries. We compiled data from 27 297 interviews of anglers across waterbodies that ranged in size from 1 to 12 113 ha. Catch rates of fish species among anglers grouped by species targeted generally differed between angling methods (bank or boat). We constructed angler–catch bipartite networks (angling method specific) between anglers and fish and measured several network metrics. There was considerable variation in networks among waterbodies, with multiple metrics influenced by waterbody size. Number of species-targeting angler groups and number of fish species caught increased with increasing waterbody size. Mean number of links for species-targeting angler groups and fish species caught also increased with waterbody size. Connectance (realized proportion of possible links) of angler–catch interaction networks decreased slower for boat anglers than for bank anglers with increasing waterbody size. Network specialization (deviation of number of interactions from expected) was not significantly related to waterbody size or angling methods. Application of bipartite networks in fishery science requires careful interpretation of outputs, especially considering the numerous confounding factors prevalent in recreational fisheries.

Results of a survey to determine demographic and business management factors associated with size and growth rate of rural mixed-animal veterinary practices.

PubMed

Brusk, Amy M; White, Brad J; Goehl, Dan R; Dhuyvetter, Kevin C

2010-12-15

To determine potential associations between demographic and business management factors and practice size and growth rate in rural mixed-animal veterinary practices. Cross-sectional survey. 54 mixed-animal practitioners. A cross-sectional survey (96 questions) was electronically disseminated. Responses were collected, and outcomes (number of veterinarians [NV], growth in number of veterinarians [NVG], gross practice income [GPI], growth in gross practice income [GPIG], gross practice income per veterinarian [GPIV], and growth in gross practice income per veterinarian [GPIVG]) were calculated. Bivariate analyses were performed and multivariable models created to determine associations between survey responses and outcomes of interest. Survey respondents were from mixed-animal practices, and most (46/54 [85.2%]) practiced in small communities (< 25,000 people). Study practices had a median ± SD NV of 2.3 ± 1.9 veterinarians, median GPI of $704,547 ± 754,839, and median GPIV of $282,065 ± 182,344. Multivariable regression analysis revealed several factors related to practice size, including the number of associate veterinarians and veterinary technicians in the practice, service fee structure, and employment of a business manager. Typically, practices had positive mean growth in NVG (4.4%), GPIG (8.5%), and GPIVG (8.1%), but growth rate was highly variable among practices. Factors associated with growth rate included main species interest, frequency for adjusting prices, use of a marketing plan, service fee structure, and sending a client newsletter. Mixed-animal practices had a large range in size and growth rate. Economic indices were impacted by common business management practices.

Interaction between carbon fibers and polymer sizing: Influence of fiber surface chemistry and sizing reactivity

NASA Astrophysics Data System (ADS)

Moosburger-Will, Judith; Bauer, Matthias; Laukmanis, Eva; Horny, Robert; Wetjen, Denise; Manske, Tamara; Schmidt-Stein, Felix; Töpker, Jochen; Horn, Siegfried

2018-05-01

Different aspects of the interaction of carbon fibers and epoxy-based polymer sizings are investigated, e.g. the wetting behavior, the strength of adhesion between fiber and sizing, and the thermal stability of the sizing layer. The influence of carbon fiber surface chemistry and sizing reactivity is investigated using fibers of different degree of anodic oxidation and sizings with different number of reactive epoxy groups per molecule. Wetting of the carbon fibers by the sizing dispersion is found to be specified by both, the degree of fiber activation and the sizing reactivity. In contrast, adhesion strength between fibers and sizing is dominated by the surface chemistry of the carbon fibers. Here, the number of surface oxygen groups seems to be the limiting factor. We also find that the sizing and the additional functionalities induced by anodic oxidation are removed by thermal treatment at 600 °C, leaving the carbon fiber in its original state after carbonization.

Real-world emission factors of fine and ultrafine aerosol particles for different traffic situations in Switzerland.

PubMed

Imhof, David; Weingartner, Ernest; Ordónez, Carlos; Gehrig, Robert; Hill, Matz; Buchmann, Brigitte; Baltensperger, Urs

2005-11-01

Extended field measurements of particle number (size distribution of particle diameters, D, in the range between 18 nm and 10 microm), surface area concentrations, and PM1 and PM10 mass concentrations were performed in Switzerland to determine traffic emissions using a comprehensive set of instruments. Measurements took place at roads with representative traffic regimes: at the kerbside of a motorway (120 km h(-1)), a highway (80-100 km h(-1)), and in an urban area with stop-and-go traffic (0-50 km h(-1)) regulated by light signals. Mean diurnal variations showed that the highest pollutant concentrations were during the morning rush hours, especially of the number density in the nanoparticle size range (D <50 nm). From the differences between up- and downwind concentrations (or differences between kerbside and background concentrations for the urban site), "real-life" emission factors were derived using NOx concentrations to calculate dilution factors. Particle number and volume emission factors of different size ranges (18-50 nm, 18-100 nm, and 18-300 nm) were derived for the total vehicle fleet and separated into a light-duty (LDV) and a heavy-duty vehicle (HDV) contribution. The total particle number emissions per vehicle were found to be about 11.7-13.5 x 10(14) particles km(-1) for constant speed (80-120 km h(-1) and 3.9 x 10(14) particles km(-1) for urban driving conditions. LDVs showed higher emission factors at constant high speed than under urban disturbed traffic flow. In contrast, HDVs emitted more air pollutants during deceleration and acceleration processes in stop-and-go traffic than with constant speed of about 80 km h(-1). On average, one HDV emits a 10-30 times higher amount of particulate air pollutants (in terms of both number and volume) than one LDV.

A Vitis vinifera basic helix-loop-helix transcription factor enhances plant cell size, vegetative biomass and reproductive yield

DOE PAGES

Lim, Sung Don; Yim, Won Choel; Liu, Degao; ...

2018-04-16

Strategies for improving plant size are critical targets for plant biotechnology to increase vegetative biomass or reproductive yield. To improve biomass production, a codon-optimized helix–loop–helix transcription factor (VvCEB1 opt) from wine grape was overexpressed in Arabidopsis thaliana resulting in significantly increased leaf number, leaf and rosette area, fresh weight and dry weight. Cell size, but typically not cell number, was increased in all tissues resulting in increased vegetative biomass and reproductive organ size, number and seed yield. Ionomic analysis of leaves revealed the VvCEB1 opt-overexpressing plants had significantly elevated, K, S and Mo contents relative to control lines. Increased Kmore » content likely drives increased osmotic potential within cells leading to greater cellular growth and expansion. To understand the mechanistic basis of VvCEB1 opt action, one transgenic line was genotyped using RNA-Seq mRNA expression profiling and revealed a novel transcriptional reprogramming network with significant changes in mRNA abundance for genes with functions in delayed flowering, pathogen–defence responses, iron homeostasis, vesicle-mediated cell wall formation and auxin-mediated signalling and responses. Direct testing of VvCEB1 opt-overexpressing plants showed that they had significantly elevated auxin content and a significantly increased number of lateral leaf primordia within meristems relative to controls, confirming that cell expansion and organ number proliferation were likely an auxin-mediated process. VvCEB1 opt overexpression in Nicotiana sylvestris also showed larger cells, organ size and biomass demonstrating the potential applicability of this innovative strategy for improving plant biomass and reproductive yield in crops.« less

A Vitis vinifera basic helix-loop-helix transcription factor enhances plant cell size, vegetative biomass and reproductive yield

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

Lim, Sung Don; Yim, Won Choel; Liu, Degao

Strategies for improving plant size are critical targets for plant biotechnology to increase vegetative biomass or reproductive yield. To improve biomass production, a codon-optimized helix–loop–helix transcription factor (VvCEB1 opt) from wine grape was overexpressed in Arabidopsis thaliana resulting in significantly increased leaf number, leaf and rosette area, fresh weight and dry weight. Cell size, but typically not cell number, was increased in all tissues resulting in increased vegetative biomass and reproductive organ size, number and seed yield. Ionomic analysis of leaves revealed the VvCEB1 opt-overexpressing plants had significantly elevated, K, S and Mo contents relative to control lines. Increased Kmore » content likely drives increased osmotic potential within cells leading to greater cellular growth and expansion. To understand the mechanistic basis of VvCEB1 opt action, one transgenic line was genotyped using RNA-Seq mRNA expression profiling and revealed a novel transcriptional reprogramming network with significant changes in mRNA abundance for genes with functions in delayed flowering, pathogen–defence responses, iron homeostasis, vesicle-mediated cell wall formation and auxin-mediated signalling and responses. Direct testing of VvCEB1 opt-overexpressing plants showed that they had significantly elevated auxin content and a significantly increased number of lateral leaf primordia within meristems relative to controls, confirming that cell expansion and organ number proliferation were likely an auxin-mediated process. VvCEB1 opt overexpression in Nicotiana sylvestris also showed larger cells, organ size and biomass demonstrating the potential applicability of this innovative strategy for improving plant biomass and reproductive yield in crops.« less

Factors governing particle number emissions in a waste-to-energy plant.

PubMed

Ozgen, Senem; Cernuschi, Stefano; Giugliano, Michele

2015-05-01

Particle number concentration and size distribution measurements were performed on the stack gas of a waste-to-energy plant which co-incinerates municipal solid waste, sewage sludge and clinical waste in two lines. Average total number of particles was found to be 4.0·10(5)cm(-3) and 1.9·10(5)cm(-3) for the line equipped with a wet flue gas cleaning process and a dry cleaning system, respectively. Ultrafine particles (dp<100nm) accounted for about 97% of total number concentration for both lines, whereas the nanoparticle (dp<50nm) contribution differed slightly between the lines (87% and 84%). The experimental data is explored statistically through some multivariate pattern identifying methods such as factor analysis and cluster analysis to help the interpretation of the results regarding the origin of the particles in the flue gas with the objective of determining the factors governing the particle number emissions. The higher moisture of the flue gas in the wet cleaning process was found to increase the particle number emissions on average by a factor of about 2 due to increased secondary formation of nanoparticles through nucleation of gaseous precursors such as sulfuric acid, ammonia and water. The influence of flue gas dilution and cooling monitored through the variation of the sampling conditions also confirms the potential effect of the secondary new particle formation in increasing the particle number emissions. This finding shows the importance of reporting the experimental conditions in detail to enable the comparison and interpretation of particle number emissions. Regarding the fuel characteristics no difference was observed in terms of particle number concentration and size distributions between the clinical waste feed and the municipal solid waste co-incineration with sludge. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reproductive traits of the small Patagonian octopus Octopus tehuelchus

NASA Astrophysics Data System (ADS)

Storero, Lorena P.; Narvarte, Maite A.; González, Raúl A.

2012-12-01

This study evaluated the reproductive features of Octopus tehuelchus in three coastal environments of San Matías Gulf (Patagonia). Monthly samples of O. tehuelchus were used to estimate size at maturity, compare seasonal changes in oocyte size frequency distributions between sites as well as oocyte number and size between female maturity stage and sites. Females in Islote Lobos had a smaller size at maturity than females in San Antonio Bay and El Fuerte, probably as a consequence of a generally smaller body size. Males in San Antonio Bay were smaller at maturity than females. O. tehuelchus is a simultaneous terminal spawner. Fecundity (expressed as number of vitellogenic oocytes in ovary) was lower in Islote Lobos, and an increase in oocyte number in relation to female total weight was found. Females in San Antonio Bay had the largest oocytes, which may indicate higher energy reserves for the embryo and therefore higher juvenile survival. There was a close relationship between reproduction, growth and condition, represented as size at maturity, number and size of vitellogenic oocytes and period of maturity and spawning. Given the local variation in some reproductive features of O. tehuelchus, studies should focus on the environmental factors, which bring about this variation, and on how it affects the dynamics of local populations.

Risk, mobility or population size? Drivers of technological richness among contact-period western North American hunter-gatherers.

PubMed

Collard, Mark; Buchanan, Briggs; O'Brien, Michael J; Scholnick, Jonathan

2013-11-19

Identifying factors that influence technological evolution in small-scale societies is important for understanding human evolution. There have been a number of attempts to identify factors that influence the evolution of food-getting technology, but little work has examined the factors that affect the evolution of other technologies. Here, we focus on variation in technological richness (total number of material items and techniques) among recent hunter-gatherers from western North America and test three hypotheses: (i) technological richness is affected by environmental risk, (ii) population size is the primary determinant of technological richness, and (iii) technological richness is constrained by residential mobility. We found technological richness to be correlated with a proxy for environmental risk-mean rainfall for the driest month-in the manner predicted by the risk hypothesis. Support for the hypothesis persisted when we controlled for shared history and intergroup contact. We found no evidence that technological richness is affected by population size or residential mobility. These results have important implications for unravelling the complexities of technological evolution.

Risk, mobility or population size? Drivers of technological richness among contact-period western North American hunter–gatherers

PubMed Central

Collard, Mark; Buchanan, Briggs; O'Brien, Michael J.; Scholnick, Jonathan

2013-01-01

Identifying factors that influence technological evolution in small-scale societies is important for understanding human evolution. There have been a number of attempts to identify factors that influence the evolution of food-getting technology, but little work has examined the factors that affect the evolution of other technologies. Here, we focus on variation in technological richness (total number of material items and techniques) among recent hunter–gatherers from western North America and test three hypotheses: (i) technological richness is affected by environmental risk, (ii) population size is the primary determinant of technological richness, and (iii) technological richness is constrained by residential mobility. We found technological richness to be correlated with a proxy for environmental risk—mean rainfall for the driest month—in the manner predicted by the risk hypothesis. Support for the hypothesis persisted when we controlled for shared history and intergroup contact. We found no evidence that technological richness is affected by population size or residential mobility. These results have important implications for unravelling the complexities of technological evolution. PMID:24101622

The relationship between nephron number, kidney size and body weight in two inbred mouse strains.

PubMed

Murawski, Inga J; Maina, Rita W; Gupta, Indra R

2010-01-01

While some reports in humans have shown that nephron number is positively correlated with height, body weight or kidney weight, other studies have not reproduced these findings. To understand the impact of genetic and environmental variation on these relationships, we examined whether nephron number correlates with body weight, kidney planar surface area, or kidney weight in two inbred mouse strains with contrasting kidney sizes but no overt renal pathology: C3H/HeJ and C57BL/6J. C3H/HeJ mice had smaller kidneys at birth and larger kidneys by adulthood, however there was no significant difference in nephron number between the two strains. We did observe a correlation between kidney size and body weight at birth and at adulthood for both strains. However, there was no relationship between nephron number and body weight or between nephron number and kidney size. From other studies, it appears that a greater than two-fold variation is required in each of these parameters in order to demonstrate these relationships, suggesting they are highly dependent on scale. Our results are therefore not surprising since there was a less than two-fold variation in each of the parameters examined. In summary, the relationship between nephron number and body or kidney size is most likely to be demonstrated when there is greater phenotypic variation either from genetic and/or environmental factors.

Joint scaling laws in functional and evolutionary categories in prokaryotic genomes

PubMed Central

Grilli, J.; Bassetti, B.; Maslov, S.; Cosentino Lagomarsino, M.

2012-01-01

We propose and study a class-expansion/innovation/loss model of genome evolution taking into account biological roles of genes and their constituent domains. In our model, numbers of genes in different functional categories are coupled to each other. For example, an increase in the number of metabolic enzymes in a genome is usually accompanied by addition of new transcription factors regulating these enzymes. Such coupling can be thought of as a proportional ‘recipe’ for genome composition of the type ‘a spoonful of sugar for each egg yolk’. The model jointly reproduces two known empirical laws: the distribution of family sizes and the non-linear scaling of the number of genes in certain functional categories (e.g. transcription factors) with genome size. In addition, it allows us to derive a novel relation between the exponents characterizing these two scaling laws, establishing a direct quantitative connection between evolutionary and functional categories. It predicts that functional categories that grow faster-than-linearly with genome size to be characterized by flatter-than-average family size distributions. This relation is confirmed by our bioinformatics analysis of prokaryotic genomes. This proves that the joint quantitative trends of functional and evolutionary classes can be understood in terms of evolutionary growth with proportional recipes. PMID:21937509

Inheritance of Vertebral Number in the Three-Spined Stickleback (Gasterosteus aculeatus)

PubMed Central

Alho, Jussi S.; Leinonen, Tuomas; Merilä, Juha

2011-01-01

Intraspecific variation in the number of vertebrae is taxonomically widespread, and both genetic and environmental factors are known to contribute to this variation. However, the relative importance of genetic versus environmental influences on variation in vertebral number has seldom been investigated with study designs that minimize bias due to non-additive genetic and maternal influences. We used a paternal half-sib design and animal model analysis to estimate heritability and causal components of variance in vertebral number in three-spined sticklebacks (Gasterosteus aculeatus). We found that both the number of vertebrae (h2 = 0.36) and body size (h2 = 0.42) were moderately heritable, whereas the influence of maternal effects was estimated to be negligible. While the number of vertebrae had a positive effect on body size, no evidence for a genetic correlation between body size and vertebral number was detected. However, there was a significant positive environmental correlation between these two traits. Our results support the generalization-in accordance with results from a review of heritability estimates for vertebral number in fish, reptiles and mammals-that the number of vertebrae appears to be moderately to highly heritable in a wide array of species. In the case of the three-spined stickleback, independent evolution of body size and number of vertebrae should be possible given the low genetic correlation between the two traits. PMID:21603609

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

Uin, Janek

The Brechtel Manufacturing Inc. (BMI) Humidified Tandem Differential Mobility Analyzer (HT-DMA Model 3002) (Brechtel and Kreidenweis 2000a,b, Henning et al. 2005, Xerxes et al. 2014) measures how aerosol particles of different initial dry sizes grow or shrink when exposed to changing relative humidity (RH) conditions. It uses two different mobility analyzers (DMA) and a humidification system to make the measurements. One DMA selects a narrow size range of dry aerosol particles, which are exposed to varying RH conditions in the humidification system. The second (humidified) DMA scans the particle size distribution output from the humidification system. Scanning a wide rangemore » of particle sizes enables the second DMA to measure changes in size or growth factor (growth factor = humidified size/dry size), due to water uptake by the particles. A Condensation Particle Counter (CPC) downstream of the second DMA counts particles as a function of selected size in order to obtain the number size distribution of particles exposed to different RH conditions.« less

SU-E-T-586: Field Size Dependence of Output Factor for Uniform Scanning Proton Beams: A Comparison of TPS Calculation, Measurement and Monte Carlo Simulation

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

Zheng, Y; Singh, H; Islam, M

2014-06-01

Purpose: Output dependence on field size for uniform scanning beams, and the accuracy of treatment planning system (TPS) calculation are not well studied. The purpose of this work is to investigate the dependence of output on field size for uniform scanning beams and compare it among TPS calculation, measurements and Monte Carlo simulations. Methods: Field size dependence was studied using various field sizes between 2.5 cm diameter to 10 cm diameter. The field size factor was studied for a number of proton range and modulation combinations based on output at the center of spread out Bragg peak normalized to amore » 10 cm diameter field. Three methods were used and compared in this study: 1) TPS calculation, 2) ionization chamber measurement, and 3) Monte Carlos simulation. The XiO TPS (Electa, St. Louis) was used to calculate the output factor using a pencil beam algorithm; a pinpoint ionization chamber was used for measurements; and the Fluka code was used for Monte Carlo simulations. Results: The field size factor varied with proton beam parameters, such as range, modulation, and calibration depth, and could decrease over 10% from a 10 cm to 3 cm diameter field for a large range proton beam. The XiO TPS predicted the field size factor relatively well at large field size, but could differ from measurements by 5% or more for small field and large range beams. Monte Carlo simulations predicted the field size factor within 1.5% of measurements. Conclusion: Output factor can vary largely with field size, and needs to be accounted for accurate proton beam delivery. This is especially important for small field beams such as in stereotactic proton therapy, where the field size dependence is large and TPS calculation is inaccurate. Measurements or Monte Carlo simulations are recommended for output determination for such cases.« less

Vandalism: Environmental and Social Factors

ERIC Educational Resources Information Center

Brown, Gregory; Devlin, Ann Sloan

2003-01-01

To explore the relationship between vandalism, college residence hall size, and a number of social factors, 688 college students completed the Core Alcohol and Drug Survey (Presley, Meilman, & Lyerla, 1994), the University Residence Environment Scale (Moos, 1988), and answered questions about their television habits and athletic participation.…

The factorization of large composite numbers on the MPP

NASA Technical Reports Server (NTRS)

Mckurdy, Kathy J.; Wunderlich, Marvin C.

1987-01-01

The continued fraction method for factoring large integers (CFRAC) was an ideal algorithm to be implemented on a massively parallel computer such as the Massively Parallel Processor (MPP). After much effort, the first 60 digit number was factored on the MPP using about 6 1/2 hours of array time. Although this result added about 10 digits to the size number that could be factored using CFRAC on a serial machine, it was already badly beaten by the implementation of Davis and Holdridge on the CRAY-1 using the quadratic sieve, an algorithm which is clearly superior to CFRAC for large numbers. An algorithm is illustrated which is ideally suited to the single instruction multiple data (SIMD) massively parallel architecture and some of the modifications which were needed in order to make the parallel implementation effective and efficient are described.

44 CFR 12.8 - Meetings.

Code of Federal Regulations, 2013 CFR

2013-10-01

... public. Meetings which are completely or partly open to the public shall be held at reasonable times and at such a place that is reasonably accessible to the public. The size of the meeting room should be determined by such factors as the size of the committee, the number of members of the public who could...

44 CFR 12.8 - Meetings.

Code of Federal Regulations, 2012 CFR

2012-10-01

... public. Meetings which are completely or partly open to the public shall be held at reasonable times and at such a place that is reasonably accessible to the public. The size of the meeting room should be determined by such factors as the size of the committee, the number of members of the public who could...

44 CFR 12.8 - Meetings.

Code of Federal Regulations, 2010 CFR

2010-10-01

... public. Meetings which are completely or partly open to the public shall be held at reasonable times and at such a place that is reasonably accessible to the public. The size of the meeting room should be determined by such factors as the size of the committee, the number of members of the public who could...

44 CFR 12.8 - Meetings.

Code of Federal Regulations, 2011 CFR

2011-10-01

... public. Meetings which are completely or partly open to the public shall be held at reasonable times and at such a place that is reasonably accessible to the public. The size of the meeting room should be determined by such factors as the size of the committee, the number of members of the public who could...

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

Tien, C; Brewer, M; Studenski, M

Purpose: Dynamic-jaw tracking maximizes the area blocked by both jaw and MLC in RapidArc. We developed a method to quantify jaw tracking. Methods: An Eclipse Scripting API (ESAPI) was used to export beam parameters for each arc’s control points. The specific beam parameters extracted were: gantry angle, control point number, meterset, x-jaw positions, y-jaw positions, MLC bank-number, MLC leaf-number, and MLC leaf-position. Each arc contained 178 control points with 120 MLC positions. MATLAB routines were written to process these parameters in order to calculate both the beam aperture (unblocked) size for each control point. An average aperture size was weightedmore » by meterset. Jaw factor was defined as the ratio between dynamic-jaw to static-jaw aperture size. Jaw factor was determined for forty retrospectively replanned patients treated with static-jaw delivery sites including lung, brain, prostate, H&N, rectum, and bladder. Results: Most patients had multiple arcs and reduced-field boosts, resulting in 151 fields. Of these, the lowest (0.4722) and highest (0.9622) jaw factor was observed in prostate and rectal cases, respectively. The median jaw factor was 0.7917 meaning there is the potential unincreased blocking by 20%. Clinically, the dynamic-jaw tracking represents an area surrounding the target which would receive MLC-only leakage transmission of 1.68% versus 0.1% with jaws. Jaw-tracking was more pronounced at areas farther from the target. In prostate patients, the rectum and bladder had 5.5% and 6.3% lower mean dose, respectively; the structures closer to the prostate such as the rectum and bladder both had 1.4% lower mean dose. Conclusion: A custom ESAPI script was coupled with a MATLAB routine in order to extract beam parameters from static-jaw plans and their replanned dynamic-jaw deliveries. The effects were quantified using jaw factor which is the ratio between the meterset weighted aperture size for dynamic-jaw fields versus static-jaw fields.« less

Litter size at birth in purebred dogs--a retrospective study of 224 breeds.

PubMed

Borge, Kaja Sverdrup; Tønnessen, Ragnhild; Nødtvedt, Ane; Indrebø, Astrid

2011-03-15

Despite the long history of purebred dogs and the large number of existing breeds, few studies of canine litter size based upon a large number of breeds exist. Previous studies are either old or include only one or a few selected breeds. The aim of this large-scale retrospective study was to estimate the mean litter size in a large population of purebred dogs and to describe some factors that might influence the litter size. A total of 10,810 litters of 224 breeds registered in the Norwegian Kennel Club from 2006 to 2007 were included in the study. The overall mean litter size at birth was 5.4 (± 0.025). A generalized linear mixed model with a random intercept for breed revealed that the litter size was significantly influenced by the size of the breed, the method of mating and the age of the bitch. A significant interaction between breed size and age was detected, in that the expected number of puppies born decreased more for older bitches of large breeds. Mean litter size increased with breed size, from 3.5 (± 0.04) puppies in miniature breeds to 7.1 (± 0.13) puppies in giant breeds. No effect on litter size was found for the season of birth or the parity of the bitch. The large number of breeds and the detail of the registered information on the litters in this study are unique. In conclusion, the size of the breed, the age of the bitch and the method of mating were found to influence litter size in purebred dogs when controlling for breed, with the size of the breed as the strongest determinant. Copyright © 2011 Elsevier Inc. All rights reserved.

Size resolved ultrafine particles emission model--a continues size distribution approach.

PubMed

Nikolova, Irina; Janssen, Stijn; Vrancken, Karl; Vos, Peter; Mishra, Vinit; Berghmans, Patrick

2011-08-15

A new parameterization for size resolved ultrafine particles (UFP) traffic emissions is proposed based on the results of PARTICULATES project (Samaras et al., 2005). It includes the emission factors from the Emission Inventory Guidebook (2006) (total number of particles, #/km/veh), the shape of the corresponding particle size distribution given in PARTICULATES and data for the traffic activity. The output of the model UFPEM (UltraFine Particle Emission Model) is a sum of continuous distributions of ultrafine particles emissions per vehicle type (passenger cars and heavy duty vehicles), fuel (petrol and diesel) and average speed representative for urban, rural and highway driving. The results from the parameterization are compared with measured total number of ultrafine particles and size distributions in a tunnel in Antwerp (Belgium). The measured UFP concentration over the entire campaign shows a close relation to the traffic activity. The modelled concentration is found to be lower than the measured in the campaign. The average emission factor from the measurement is 4.29E+14 #/km/veh whereas the calculated is around 30% lower. A comparison of emission factors with literature is done as well and in overall a good agreement is found. For the size distributions it is found that the measured distributions consist of three modes--Nucleation, Aitken and accumulation and most of the ultrafine particles belong to the Nucleation and the Aitken modes. The modelled Aitken mode (peak around 0.04-0.05 μm) is found in a good agreement both as amplitude of the peak and the number of particles whereas the modelled Nucleation mode is shifted to smaller diameters and the peak is much lower that the observed. Time scale analysis shows that at 300 m in the tunnel coagulation and deposition are slow and therefore neglected. The UFPEM emission model can be used as a source term in dispersion models. Copyright © 2011 Elsevier B.V. All rights reserved.

Carbide factor predicts rolling-element bearing fatigue life

NASA Technical Reports Server (NTRS)

Chevalier, J. L.; Zaretsky, E. V.

1973-01-01

Analysis was made to determine correlation between number and size of carbide particles and rolling-element fatigue. Correlation was established, and carbide factor was derived that can be used to predict fatigue life more effectively than such variables as heat treatment, chemical composition, and hardening mechanism.

Worldwide orthopaedic research activity 2010-2014: Publication rates in the top 15 orthopaedic journals related to population size and gross domestic product.

PubMed

Hohmann, Erik; Glatt, Vaida; Tetsworth, Kevin

2017-06-18

To perform a bibliometric analysis of publications rates in orthopedics in the top 15 orthopaedic journals. Based on their 2015 impact factor, the fifteen highest ranked orthopaedic journals between January 2010 and December 2014 were used to establish the total number of publications; cumulative impact factor points (IF) per country were determined, and normalized to population size, GDP, and GDP/capita, comparison to the median country output and the global leader. Twenty-three thousand and twenty-one orthopaedic articles were published, with 66 countries publishing. The United States had 8149 publications, followed by the United Kingdom (1644) and Japan (1467). The highest IF was achieved by the United States (24744), United Kingdom (4776), and Japan (4053). Normalized by population size Switzerland lead. Normalized by GDP, Croatia was the top achiever. Adjusting GDP/capita, for publications and IF, China, India, and the United States were the leaders. Adjusting for population size and GDP, 28 countries achieved numbers of publications to be considered at least equivalent with the median academic output. Adjusting GDP/capita only China and India reached the number of publications to be considered equivalent to the current global leader, the United States. Five countries were responsible for 60% of the orthopaedic research output over this 5-year period. After correcting for GDP/capita, only 28 of 66 countries achieved a publication rate equivalent to the median country. The United States, United Kingdom, South Korea, Japan, and Germany were the top five countries for both publication totals and cumulative impact factor points.

Entrance dose measurements for in‐vivo diode dosimetry: Comparison of correction factors for two types of commercial silicon diode detectors

PubMed Central

Zhu, X. R.

2000-01-01

Silicon diode dosimeters have been used routinely for in‐vivo dosimetry. Despite their popularity, an appropriate implementation of an in‐vivo dosimetry program using diode detectors remains a challenge for clinical physicists. One common approach is to relate the diode readout to the entrance dose, that is, dose to the reference depth of maximum dose such as dmax for the 10×10 cm2 field. Various correction factors are needed in order to properly infer the entrance dose from the diode readout, depending on field sizes, target‐to‐surface distances (TSD), and accessories (such as wedges and compensate filters). In some clinical practices, however, no correction factor is used. In this case, a diode‐dosimeter‐based in‐vivo dosimetry program may not serve the purpose effectively; that is, to provide an overall check of the dosimetry procedure. In this paper, we provide a formula to relate the diode readout to the entrance dose. Correction factors for TSD, field size, and wedges used in this formula are also clearly defined. Two types of commercial diode detectors, ISORAD (n‐type) and the newly available QED (p‐type) (Sun Nuclear Corporation), are studied. We compared correction factors for TSDs, field sizes, and wedges. Our results are consistent with the theory of radiation damage of silicon diodes. Radiation damage has been shown to be more serious for n‐type than for p‐type detectors. In general, both types of diode dosimeters require correction factors depending on beam energy, TSD, field size, and wedge. The magnitudes of corrections for QED (p‐type) diodes are smaller than ISORAD detectors. PACS number(s): 87.66.–a, 87.52.–g PMID:11674824

Sample size and allocation of effort in point count sampling of birds in bottomland hardwood forests

USGS Publications Warehouse

Smith, W.P.; Twedt, D.J.; Cooper, R.J.; Wiedenfeld, D.A.; Hamel, P.B.; Ford, R.P.; Ralph, C. John; Sauer, John R.; Droege, Sam

1995-01-01

To examine sample size requirements and optimum allocation of effort in point count sampling of bottomland hardwood forests, we computed minimum sample sizes from variation recorded during 82 point counts (May 7-May 16, 1992) from three localities containing three habitat types across three regions of the Mississippi Alluvial Valley (MAV). Also, we estimated the effect of increasing the number of points or visits by comparing results of 150 four-minute point counts obtained from each of four stands on Delta Experimental Forest (DEF) during May 8-May 21, 1991 and May 30-June 12, 1992. For each stand, we obtained bootstrap estimates of mean cumulative number of species each year from all possible combinations of six points and six visits. ANOVA was used to model cumulative species as a function of number of points visited, number of visits to each point, and interaction of points and visits. There was significant variation in numbers of birds and species between regions and localities (nested within region); neither habitat, nor the interaction between region and habitat, was significant. For a = 0.05 and a = 0.10, minimum sample size estimates (per factor level) varied by orders of magnitude depending upon the observed or specified range of desired detectable difference. For observed regional variation, 20 and 40 point counts were required to accommodate variability in total individuals (MSE = 9.28) and species (MSE = 3.79), respectively, whereas ? 25 percent of the mean could be achieved with five counts per factor level. Sample size sufficient to detect actual differences of Wood Thrush (Hylocichla mustelina) was >200, whereas the Prothonotary Warbler (Protonotaria citrea) required <10 counts. Differences in mean cumulative species were detected among number of points visited and among number of visits to a point. In the lower MAV, mean cumulative species increased with each added point through five points and with each additional visit through four visits. Although no interaction was detected between number of points and number of visits, when paired reciprocals were compared, more points invariably yielded a significantly greater cumulative number of species than more visits to a point. Still, 36 point counts per stand during each of two breeding seasons detected only 52 percent of the known available species pool in DEF.

Finite-size scaling of survival probability in branching processes

NASA Astrophysics Data System (ADS)

Garcia-Millan, Rosalba; Font-Clos, Francesc; Corral, Álvaro

2015-04-01

Branching processes pervade many models in statistical physics. We investigate the survival probability of a Galton-Watson branching process after a finite number of generations. We derive analytically the existence of finite-size scaling for the survival probability as a function of the control parameter and the maximum number of generations, obtaining the critical exponents as well as the exact scaling function, which is G (y ) =2 y ey /(ey-1 ) , with y the rescaled distance to the critical point. Our findings are valid for any branching process of the Galton-Watson type, independently of the distribution of the number of offspring, provided its variance is finite. This proves the universal behavior of the finite-size effects in branching processes, including the universality of the metric factors. The direct relation to mean-field percolation is also discussed.

Constructing Ability Groups in the Secondary School: Issues in Practice.

ERIC Educational Resources Information Center

Ireson, Judith; Clark, Helen; Hallam, Susan

2002-01-01

Examines grouping practices in 45 secondary schools in England based on information provided by curriculum managers and department heads about allocation procedures, factors affecting the size and number of student groups, movement between groups, pressures and constraints on movement, and behavioral and motivational factors. Finds wide variety of…

A Cell Size Theory of Aging.

PubMed

Patra, Krushna C; Bardeesy, Nabeel

2018-06-18

The factors determining longevity of different animals are incompletely defined. In this issue of Developmental Cell, Anzi et al. (2018) show that distinct strategies for postnatal pancreatic growth operate in different mammals and correlate with lifespan, with short-lived species exhibiting increasing pancreatic cell size and long-lived animals increasing cell number. Copyright © 2018 Elsevier Inc. All rights reserved.

How Hives Collapse: Allee Effects, Ecological Resilience, and the Honey Bee

PubMed Central

Dennis, Brian; Kemp, William P.

2016-01-01

We construct a mathematical model to quantify the loss of resilience in collapsing honey bee colonies due to the presence of a strong Allee effect. In the model, recruitment and mortality of adult bees have substantial social components, with recruitment enhanced and mortality reduced by additional adult bee numbers. The result is an Allee effect, a net per-individual rate of hive increase that increases as a function of adult bee numbers. The Allee effect creates a critical minimum size in adult bee numbers, below which mortality is greater than recruitment, with ensuing loss of viability of the hive. Under ordinary and favorable environmental circumstances, the critical size is low, and hives remain large, sending off viably-sized swarms (naturally or through beekeeping management) when hive numbers approach an upper stable equilibrium size (carrying capacity). However, both the lower critical size and the upper stable size depend on many parameters related to demographic rates and their enhancement by bee sociality. Any environmental factors that increase mortality, decrease recruitment, or interfere with the social moderation of these rates has the effect of exacerbating the Allee effect by increasing the lower critical size and substantially decreasing the upper stable size. As well, the basin of attraction to the upper stable size, defined by the model potential function, becomes narrower and shallower, indicating the loss of resilience as the hive becomes subjected to increased risk of falling below the critical size. Environmental effects of greater severity can cause the two equilibria to merge and the basin of attraction to the upper stable size to disappear, resulting in collapse of the hive from any initial size. The model suggests that multiple proximate causes, among them pesticides, mites, pathogens, and climate change, working singly or in combinations, could trigger hive collapse. PMID:26910061

Herd size and bovine tuberculosis persistence in cattle farms in Great Britain.

PubMed

Brooks-Pollock, Ellen; Keeling, Matt

2009-12-01

Bovine tuberculosis (bTB) infection in cattle is one of the most complex and persistent problems faced by the cattle industry in Great Britain today. While a number of factors have been identified as increasing the risk of infection, there has been little analysis on the causes of persistent infection within farms. In this article, we use the Cattle Tracing System to examine changes in herd size and VetNet data to correlate herd size with clearance of bTB. We find that the number of active farms fell by 16.3% between 2002 and 2007. The average farm size increased by 17.9% between 2002 and 2005. Using a measure similar to the Critical Community Size, the VetNet data reveal that herd size is positively correlated with disease persistence. Since economic policy and subsidies have been shown to influence farm size, we used a simple financial model for ideal farm size which includes disease burden to conclude that increasing herd size for efficiency gains may contribute to increased disease incidence.

Effect of solute elements in Ni alloys on blistering under He + and D + ion irradiation

NASA Astrophysics Data System (ADS)

Wakai, E.; Ezawa, T.; Takenaka, T.; Imamura, J.; Tanabe, T.; Oshima, R.

2007-08-01

Effects of solute atoms on microstructural evolution and blister formation have been investigated using Ni alloys under 25 keV He + and 20 keV D + irradiation at 500 °C to a dose of about 4 × 10 21 ions/m 2. The specimens used were pure Ni, Ni-Si, Ni-Co, Ni-Cu, Ni-Mn and Ni-Pd alloys. The volume size factors of solute elements for the Ni alloys range from -5.8% to +63.6%. The formations of blisters were observed in the helium-irradiated specimens, but not in the deuteron-irradiated specimens. The areal number densities of blisters increased with volume size difference of solute atoms. The dependence of volume size on the areal number densities of blisters was very similar to that of the number densities of bubbles on solute atoms. The size of the blisters inversely decreased with increasing size of solute atoms. The formation of blisters was intimately related to the bubble growth, and the gas pressure model for the formation of blisters was supported by this study.

Socioeconomic Factors Influence Physical Activity and Sport in Quebec Schools.

PubMed

Morin, Pascale; Lebel, Alexandre; Robitaille, Éric; Bisset, Sherri

2016-11-01

School environments providing a wide selection of physical activities and sufficient facilities are both essential and formative to ensure young people adopt active lifestyles. We describe the association between school opportunities for physical activity and socioeconomic factors measured by low-income cutoff index, school size (number of students), and neighborhood population density. A cross-sectional survey using a 2-stage stratified sampling method built a representative sample of 143 French-speaking public schools in Quebec, Canada. Self-administered questionnaires collected data describing the physical activities offered and schools' sports facilities. Descriptive and bivariate analyses were performed separately for primary and secondary schools. In primary schools, school size was positively associated with more intramural and extracurricular activities, more diverse interior facilities, and activities promoting active transportation. Low-income primary schools were more likely to offer a single gym. Low-income secondary schools offered lower diversity of intramural activities and fewer exterior sporting facilities. High-income secondary schools with a large school size provided a greater number of opportunities, larger infrastructures, and a wider selection of physical activities than smaller low-income schools. Results reveal an overall positive association between school availability of physical and sport activity and socioeconomic factors. © 2016, American School Health Association.

Aneurysms of the anterior and posterior cerebral circulation: comparison of the morphometric features.

PubMed

Tykocki, Tomasz; Kostkiewicz, Bogusław

2014-09-01

Intracranial aneurysms (IAs) located in the posterior circulation are considered to have higher annual bleed rates than those in the anterior circulation. The aim of the study was to compare the morphometric factors differentiating between IAs located in the anterior and posterior cerebral circulation. A total number of 254 IAs diagnosed between 2009 and 2012 were retrospectively analyzed. All patients qualified for diagnostic, three-dimensional rotational angiography. IAs were assigned to either the anterior or posterior cerebral circulation subsets for the analysis. Means were compared with a t-test. The univariate and stepwise logistic regression analyses were used to determine the predictors of morphometric differences between the groups. For the defined predictors, ROC (receiver-operating characteristic) curves and interactive dot diagrams were calculated with the cutoff values of the morphometric factors. The number of anterior cerebral circulation IAs was 179 (70.5 %); 141 (55.5 %) aneurysms were ruptured. Significant differences between anterior and posterior circulation IAs were found for: the parent artery size (5.08 ± 1.8 mm vs. 3.95 ± 1.5 mm; p < 0.05), size ratio (2.22 ± 0.9 vs. 3.19 ± 1.8; p < 0.045) and aspect ratio (AR) (1.91 ± 0.8 vs. 2.75 ± 1.8; p = 0.02). Predicting factors differentiating anterior and posterior circulation IAs were: the AR (OR = 2.20; 95 % CI 1.80-270; Is 270 correct or should it be 2.70 and parent artery size (OR = 0.44; 95 % CI 0.38-0.54). The cutoff point in the ROC curve was 2.185 for the AR and 4.89 mm for parent artery size. Aspect ratio and parent artery size were found to be predictive morphometric factors in differentiating between anterior and posterior cerebral IAs.

Determinants of family size in a Gulf Arab state: a comparison between two areas.

PubMed

Hamadeh, Randah R; Al-Roomi, Khaldoon; Masuadi, Emad

2008-09-01

The rapid economic transition in the Gulf Arab countries has resulted in marked changes in fertility and marriage patterns and a decrease in the number of children per family. Yet little is known about the determinants of family size in urban and less urban areas. A cross-sectional study was carried out on 450 Kuwaiti women aged 20-60 years who attended health care centres in Al Asima and Al Jahra governorates. A semi-structured questionnaire was administered through face-to-face interview which included variables on socio-demographic characteristics, family size, actual and ideal spacing, marriage related variables, health conditions and utilization of health services. Both univariate and multivariate analyses were performed to identify the factors that affect family size. The socio-economic indicators were significantly better in Al Asima, the capital, than in Al Jahra, a less urbanized area. On average, family size for the total sample was 5.97 +/- 0.114 with a larger size (6.27 +/- 0.242) in Al Jahra than in Al Asima (5.80 +/- 0.118) but without a significant difference. Al Jahra women reported a larger number of deliveries and past pregnancies but a lower usage of contraceptive measures. The total fertility rate was 3.65 in Al Asima, 3.84 in Al Jahra and 3.71 births per woman in the total population. Family size was inversely related to the educational level of women and their husbands. Currently employed women had a smaller family size (5.22 +/- 0.119) than the unemployed (6.81 +/- 0.187); p < 0.0005. Health problems in the interviewee or her husband played a minor role in the decision to have more children. Families where the husband was the decision-maker on the number of children had a significantly larger family size (6.91 +/- 0.451) than families where the couple both participated in the decision (5.83 +/- 0.129; p = 0.032). The duration of marriage, ideal number of children, age of women at last delivery, number of rooms and the crowding index had significant positive effects on family size, whereas age at first delivery, duration between two consecutive pregnancies and history of past abortions were inversely related to family size in the stepwise multiple regression analysis. Although women in the less urbanized areas in the Gulf Arab populations are more disadvantaged with respect to socio-economic characteristics than women in the more urbanized areas, there were no significant differences in family size in these contrasting communities. The impact of socio-demographic characteristics on family size was minor compared to factors related to fertility and the husband's desire to have more children. Fertility and family planning policies should consider these issues in order to promote more effective programmes.

Home range size of Tengmalm's owl during breeding in Central Europe is determined by prey abundance.

PubMed

Kouba, Marek; Bartoš, Luděk; Tomášek, Václav; Popelková, Alena; Šťastný, Karel; Zárybnická, Markéta

2017-01-01

Animal home ranges typically characterized by their size, shape and a given time interval can be affected by many different biotic and abiotic factors. However, despite the fact that many studies have addressed home ranges, our knowledge of the factors influencing the size of area occupied by different animals is, in many cases, still quite poor, especially among raptors. Using radio-telemetry (VHF; 2.1 g tail-mounted tags) we studied movements of 20 Tengmalm's owl (Aegolius funereus) males during the breeding season in a mountain area of Central Europe (the Czech Republic, the Ore Mountains: 50° 40' N, 13° 35' E) between years 2006-2010, determined their average hunting home range size and explored what factors affected the size of home range utilised. The mean breeding home range size calculated according to 95% fixed kernel density estimator was 190.7 ± 65.7 ha (± SD) with a median value of 187.1 ha. Home range size was affected by prey abundance, presence or absence of polygyny, the number of fledglings, and weather conditions. Home range size increased with decreasing prey abundance. Polygynously mated males had overall larger home range than those mated monogamously, and individuals with more fledged young possessed larger home range compared to those with fewer raised fledglings. Finally, we found that home ranges recorded during harsh weather (nights with strong wind speed and/or heavy rain) were smaller in size than those registered during better weather. Overall, the results provide novel insights into what factors may influence home range size and emphasize the prey abundance as a key factor for breeding dynamics in Tengmalm's owl.

Measurement of composite resin filler particles by using scanning electron microscopy and digital imaging.

PubMed

Jaarda, M J; Lang, B R; Wang, R F; Edwards, C A

1993-04-01

Composite resins are routinely classified on the basis of filler particle size for purposes of research, clinical applications, and communications. The size and characterizations of filler particles have also been considered a significant factor in the rate of wear of composites. Making valid correlations between the filler particles within a composite and wear requires accuracy of filler particle size and characterization. This study was initiated to examine two methods that would (1) qualify the filler particle content of a composite resin and (2) quantify the number, size, and the area occupied by the filler particles in composite resins. Three composite resins, BIS-FIL I, Visio-Fil, and Ful-Fil, were selected as the materials to be examined, on the basis of their published composite classification type as fine particle. The findings demonstrated that scientific methods are available to examine qualitatively and measure quantitatively the composite resin filler particles in terms of their numbers, sizes, and area occupied by use of a scanning electron microscope and digital imaging. Significant differences in the filler particle numbers, sizes, and the area occupied were found for the three composite resins in this study that were classified as fine particle.

Considerations for throughfall chemistry sample-size determination

Treesearch

Pamela J. Edwards; Paul Mohai; Howard G. Halverson; David R. DeWalle

1989-01-01

Both the number of trees sampled per species and the number of sampling points under each tree are important throughfall sampling considerations. Chemical loadings obtained from an urban throughfall study were used to evaluate the relative importance of both of these sampling factors in tests for determining species' differences. Power curves for detecting...

[Local recurrence based on size after conservative surgery in breast cancer stage T1-T2. A population-based study].

PubMed

Martínez-Ramos, David; Fortea-Sanchis, Carlos; Escrig-Sos, Javier; Prats-de Puig, Miguel; Queralt-Martín, Raquel; Salvador-Sanchis, José Luís

2014-01-01

Conservative surgery can be regarded as the standard treatment for most early stage breast tumors. However, a minority of patients treated with conservative surgery will present local or locoregional recurrence. Therefore, it is of interest to evaluate the possible factors associated with this recurrence. A population-based retrospective study using data from the Tumor Registry of Castellón (Valencia, Spain) of patients operated on for primary nonmetastatic breast cancer between January 2000 and December 2008 was designed. Kaplan-Meier curves and log-rank test to estimate 5-year local recurrence were used. Two groups of patients were defined, one with conservative surgery and another with nonconservative surgery. Cox multivariate analysis was conducted. The total number of patients was 410. Average local recurrence was 6.8%. In univariate analysis, only tumor size and lymph node involvement showed significant differences. On multivariate analysis, independent prognostic factors were conservative surgery (hazard ratio [HR] 4.62; 95% confidence interval [CI]: 1.12-16.82), number of positive lymph nodes (HR 1.07; 95% CI: 1.01-1.17) and tumor size (in mm) (HR 1.02; 95% CI: 1.01-1.06). Local recurrence after breast-conserving surgery is higher in tumors >2 cm. Although tumor size should not be a contraindication for conservative surgery, it should be a risk factor to be considered.

Experimentally Induced Repeated Anhydrobiosis in the Eutardigrade Richtersius coronifer.

PubMed

Czernekova, Michaela; Jönsson, K Ingemar

2016-01-01

Tardigrades represent one of the main animal groups with anhydrobiotic capacity at any stage of their life cycle. The ability of tardigrades to survive repeated cycles of anhydrobiosis has rarely been studied but is of interest to understand the factors constraining anhydrobiotic survival. The main objective of this study was to investigate the patterns of survival of the eutardigrade Richtersius coronifer under repeated cycles of desiccation, and the potential effect of repeated desiccation on size, shape and number of storage cells. We also analyzed potential change in body size, gut content and frequency of mitotic storage cells. Specimens were kept under non-cultured conditions and desiccated under controlled relative humidity. After each desiccation cycle 10 specimens were selected for analysis of morphometric characteristics and mitosis. The study demonstrates that tardigrades may survive up to 6 repeated desiccations, with declining survival rates with increased number of desiccations. We found a significantly higher proportion of animals that were unable to contract properly into a tun stage during the desiccation process at the 5th and 6th desiccations. Also total number of storage cells declined at the 5th and 6th desiccations, while no effect on storage cell size was observed. The frequency of mitotic storage cells tended to decline with higher number of desiccation cycles. Our study shows that the number of consecutive cycles of anhydrobiosis that R. coronifer may undergo is limited, with increased inability for tun formation and energetic constraints as possible causal factors.

Experimentally Induced Repeated Anhydrobiosis in the Eutardigrade Richtersius coronifer

PubMed Central

2016-01-01

Tardigrades represent one of the main animal groups with anhydrobiotic capacity at any stage of their life cycle. The ability of tardigrades to survive repeated cycles of anhydrobiosis has rarely been studied but is of interest to understand the factors constraining anhydrobiotic survival. The main objective of this study was to investigate the patterns of survival of the eutardigrade Richtersius coronifer under repeated cycles of desiccation, and the potential effect of repeated desiccation on size, shape and number of storage cells. We also analyzed potential change in body size, gut content and frequency of mitotic storage cells. Specimens were kept under non-cultured conditions and desiccated under controlled relative humidity. After each desiccation cycle 10 specimens were selected for analysis of morphometric characteristics and mitosis. The study demonstrates that tardigrades may survive up to 6 repeated desiccations, with declining survival rates with increased number of desiccations. We found a significantly higher proportion of animals that were unable to contract properly into a tun stage during the desiccation process at the 5th and 6th desiccations. Also total number of storage cells declined at the 5th and 6th desiccations, while no effect on storage cell size was observed. The frequency of mitotic storage cells tended to decline with higher number of desiccation cycles. Our study shows that the number of consecutive cycles of anhydrobiosis that R. coronifer may undergo is limited, with increased inability for tun formation and energetic constraints as possible causal factors. PMID:27828978

Understanding effects in reviews of implementation interventions using the Theoretical Domains Framework.

PubMed

Little, Elizabeth A; Presseau, Justin; Eccles, Martin P

2015-06-17

Behavioural theory can be used to better understand the effects of behaviour change interventions targeting healthcare professional behaviour to improve quality of care. However, the explicit use of theory is rarely reported despite interventions inevitably involving at least an implicit idea of what factors to target to implement change. There is a quality of care gap in the post-fracture investigation (bone mineral density (BMD) scanning) and management (bisphosphonate prescription) of patients at risk of osteoporosis. We aimed to use the Theoretical Domains Framework (TDF) within a systematic review of interventions to improve quality of care in post-fracture investigation. Our objectives were to explore which theoretical factors the interventions in the review may have been targeting and how this might be related to the size of the effect on rates of BMD scanning and osteoporosis treatment with bisphosphonate medication. A behavioural scientist and a clinician independently coded TDF domains in intervention and control groups. Quantitative analyses explored the relationship between intervention effect size and total number of domains targeted, and as number of different domains targeted. Nine randomised controlled trials (RCTs) (10 interventions) were analysed. The five theoretical domains most frequently coded as being targeted by the interventions in the review included "memory, attention and decision processes", "knowledge", "environmental context and resources", "social influences" and "beliefs about consequences". Each intervention targeted a combination of at least four of these five domains. Analyses identified an inverse relationship between both number of times and number of different domains coded and the effect size for BMD scanning but not for bisphosphonate prescription, suggesting that the more domains the intervention targeted, the lower the observed effect size. When explicit use of theory to inform interventions is absent, it is possible to retrospectively identify the likely targeted factors using theoretical frameworks such as the TDF. In osteoporosis management, this suggested that several likely determinants of healthcare professional behaviour appear not yet to have been considered in implementation interventions. This approach may serve as a useful basis for using theory-based frameworks such as the TDF to retrospectively identify targeted factors within systematic reviews of implementation interventions in other implementation contexts.

The Effects of Transient Emotional State and Workload on Size Scaling in Perspective Displays

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

Tuan Q. Tran; Kimberly R. Raddatz

2006-10-01

Previous research has been devoted to the study of perceptual (e.g., number of depth cues) and cognitive (e.g., instructional set) factors that influence veridical size perception in perspective displays. However, considering that perspective displays have utility in high workload environments that often induce high arousal (e.g., aircraft cockpits), the present study sought to examine the effect of observers’ emotional state on the ability to perceive and judge veridical size. Within a dual-task paradigm, observers’ ability to make accurate size judgments was examined under conditions of induced emotional state (positive, negative, neutral) and high and low workload. Results showed that participantsmore » in both positive and negative induced emotional states were slower to make accurate size judgments than those not under induced emotional arousal. Results suggest that emotional state is an important factor that influences visual performance on perspective displays and is worthy of further study.« less

Point counts from clustered populations: Lessons from an experiment with Hawaiian crows

USGS Publications Warehouse

Hayward, G.D.; Kepler, C.B.; Scott, J.M.

1991-01-01

We designed an experiment to identify factors contributing most to error in counts of Hawaiian Crow or Alala (Corvus hawaiiensis) groups that are detected aurally. Seven observers failed to detect calling Alala on 197 of 361 3-min point counts on four transects extending from cages with captive Alala. A detection curve describing the relation between frequency of flock detection and distance typified the distribution expected in transect or point counts. Failure to detect calling Alala was affected most by distance, observer, and Alala calling frequency. The number of individual Alala calling was not important in detection rate. Estimates of the number of Alala calling (flock size) were biased and imprecise: average difference between number of Alala calling and number heard was 3.24 (.+-. 0.277). Distance, observer, number of Alala calling, and Alala calling frequency all contributed to errors in estimates of group size (P < 0.0001). Multiple regression suggested that number of Alala calling contributed most to errors. These results suggest that well-designed point counts may be used to estimate the number of Alala flocks but cast doubt on attempts to estimate flock size when individuals are counted aurally.

Factors influencing piglet pre-weaning mortality in 47 commercial swine herds in Thailand.

PubMed

Nuntapaitoon, Morakot; Tummaruk, Padet

2018-01-01

The present study aims to determine the occurrence of piglet pre-weaning mortality in commercial swine herds in Thailand in relation to piglet, sow, and environmental factors. Data were collected from the database of the computerized recording system from 47 commercial swine herds in Thailand. The raw data were carefully scrutinized for accuracy. Litters with a lactation length < 16 days or >28 days were excluded. In total, 199,918 litters from 74,088 sows were included in the analyses. Piglet pre-weaning mortality at the individual sow level was calculated as piglet pre-weaning mortality (%) = (number of littermate pigs - number of piglets at weaning) / number of littermate pigs. Litters were classified according to sow parity numbers (1, 2-5, and 6-9), average birth weight of the piglets (0.80-1.29, 1.30-1.79, 1.80-2.50 kg), number of littermate pigs (5-7, 8-10, 11-12, and 13-15 piglets), and size of the herd (small, medium, and large). Pearson correlations were conducted to analyze the associations between piglet pre-weaning mortality and reproductive parameters. Additionally, a general linear model procedure was performed to analyze the various factors influencing piglet pre-weaning mortality. On average, piglet pre-weaning mortality was 11.2% (median = 9.1%) and varied among herds from 4.8 to 19.2%. Among all the litters, 62.1, 18.1, and 19.8% of the litters had a piglet pre-weaning mortality rate of 0-10, 11-20, and greater than 20%, respectively. As the number of littermate pigs increased, piglet pre-weaning mortality also increased (r = 0.390, P < 0.001). Litters with 13-16 littermate pigs had a higher piglet pre-weaning mortality than litters with 5-7, 8-10, and 11-12 littermate pigs (20.8, 7.8, 7.2, and 11.2%, respectively; P < 0.001). Piglet pre-weaning mortality in large-sized herds was higher than that in small- and medium-sized herds (13.6, 10.6, and 11.2%, respectively; P < 0.001). Interestingly, in all categories of herd size, piglet pre-weaning mortality was increased almost two times when the number of littermates increased from 11-12 to 13-16 piglets. Furthermore, piglets with birth weights of 0.80-1.29 kg in large-sized herds had a higher risk of mortality than those in small- and medium-sized herds (15.3, 10.9, and 12.2%, respectively, P < 0.001). In conclusion, in commercial swine herds in the tropics, piglet pre-weaning mortality averaged 11.2% and varied among herds from 4.8 to 19.2%. The litters with 13-16 littermate pigs had piglet pre-weaning mortality of up to 20.8%. Piglets with low birth weight (0.80-1.29 kg) had a higher risk of pre-weaning mortality. Management strategies for reducing piglet pre-weaning mortality in tropical climates should be emphasized in litters with a high number of littermate pigs, low piglet birth weights, and large herd sizes.

ARM Evaluation Product : Droplet Number Concentration Value-Added Product

DOE Data Explorer

Riihimaki, Laura

2014-05-15

Cloud droplet number concentration is an important factor in understanding aerosol-cloud interactions. As aerosol concentration increases, it is expected that droplet number concentration, Nd, will increase and droplet size decrease, for a given liquid water path (Twomey 1977), which will greatly affect cloud albedo as smaller droplets reflect more shortwave radiation. However, the magnitude and variability of these processes under different environmental conditions is still uncertain. McComiskey et al. (2009) have implemented a method, based on Boers and Mitchell (1994), for calculating Nd from ground-based remote sensing measurements of optical depth and liquid water path. They show that the magnitude of the aerosol-cloud interactions (ACI) varies with a range of factors, including the relative value of the cloud liquid water path (LWP), the aerosol size distribution, and the cloud updraft velocity. Estimates of Nd under a range of cloud types and conditions and at a variety of sites are needed to further quantify the impacts of aerosol cloud interactions.

Inequality of Size and Size Increment in Pinus banksiana in Relation to Stand Dynamics and Annual Growth Rate

PubMed Central

Metsaranta, Juha M.; Lieffers, Victor J.

2008-01-01

Background and Aims Changes in size inequality in tree populations are often attributed to changes in the mode of competition over time. The mode of competition may also fluctuate annually in response to variation in growing conditions. Factors causing growth rate to vary can also influence competition processes, and thus influence how size hierarchies develop. Methods Detailed data obtained by tree-ring reconstruction were used to study annual changes in size and size increment inequality in several even-aged, fire-origin jack pine (Pinus banksiana) stands in the boreal shield and boreal plains ecozones in Saskatchewan and Manitoba, Canada, by using the Gini and Lorenz asymmetry coefficients. Key Results The inequality of size was related to variables reflecting long-term stand dynamics (e.g. stand density, mean tree size and average competition, as quantified using a distance-weighted absolute size index). The inequality of size increment was greater and more variable than the inequality of size. Inequality of size increment was significantly related to annual growth rate at the stand level, and was higher when growth rate was low. Inequality of size increment was usually due primarily to large numbers of trees with low growth rates, except during years with low growth rate when it was often due to small numbers of trees with high growth rates. The amount of competition to which individual trees were subject was not strongly related to the inequality of size increment. Conclusions Differences in growth rate among trees during years of poor growth may form the basis for development of size hierarchies on which asymmetric competition can act. A complete understanding of the dynamics of these forests requires further evaluation of the way in which factors that influence variation in annual growth rate also affect the mode of competition and the development of size hierarchies. PMID:18089583

Inequality of size and size increment in Pinus banksiana in relation to stand dynamics and annual growth rate.

PubMed

Metsaranta, Juha M; Lieffers, Victor J

2008-03-01

Changes in size inequality in tree populations are often attributed to changes in the mode of competition over time. The mode of competition may also fluctuate annually in response to variation in growing conditions. Factors causing growth rate to vary can also influence competition processes, and thus influence how size hierarchies develop. Detailed data obtained by tree-ring reconstruction were used to study annual changes in size and size increment inequality in several even-aged, fire-origin jack pine (Pinus banksiana) stands in the boreal shield and boreal plains ecozones in Saskatchewan and Manitoba, Canada, by using the Gini and Lorenz asymmetry coefficients. The inequality of size was related to variables reflecting long-term stand dynamics (e.g. stand density, mean tree size and average competition, as quantified using a distance-weighted absolute size index). The inequality of size increment was greater and more variable than the inequality of size. Inequality of size increment was significantly related to annual growth rate at the stand level, and was higher when growth rate was low. Inequality of size increment was usually due primarily to large numbers of trees with low growth rates, except during years with low growth rate when it was often due to small numbers of trees with high growth rates. The amount of competition to which individual trees were subject was not strongly related to the inequality of size increment. Differences in growth rate among trees during years of poor growth may form the basis for development of size hierarchies on which asymmetric competition can act. A complete understanding of the dynamics of these forests requires further evaluation of the way in which factors that influence variation in annual growth rate also affect the mode of competition and the development of size hierarchies.

Worldwide orthopaedic research activity 2010-2014: Publication rates in the top 15 orthopaedic journals related to population size and gross domestic product

PubMed Central

Hohmann, Erik; Glatt, Vaida; Tetsworth, Kevin

2017-01-01

AIM To perform a bibliometric analysis of publications rates in orthopedics in the top 15 orthopaedic journals. METHODS Based on their 2015 impact factor, the fifteen highest ranked orthopaedic journals between January 2010 and December 2014 were used to establish the total number of publications; cumulative impact factor points (IF) per country were determined, and normalized to population size, GDP, and GDP/capita, comparison to the median country output and the global leader. RESULTS Twenty-three thousand and twenty-one orthopaedic articles were published, with 66 countries publishing. The United States had 8149 publications, followed by the United Kingdom (1644) and Japan (1467). The highest IF was achieved by the United States (24744), United Kingdom (4776), and Japan (4053). Normalized by population size Switzerland lead. Normalized by GDP, Croatia was the top achiever. Adjusting GDP/capita, for publications and IF, China, India, and the United States were the leaders. Adjusting for population size and GDP, 28 countries achieved numbers of publications to be considered at least equivalent with the median academic output. Adjusting GDP/capita only China and India reached the number of publications to be considered equivalent to the current global leader, the United States. CONCLUSION Five countries were responsible for 60% of the orthopaedic research output over this 5-year period. After correcting for GDP/capita, only 28 of 66 countries achieved a publication rate equivalent to the median country. The United States, United Kingdom, South Korea, Japan, and Germany were the top five countries for both publication totals and cumulative impact factor points. PMID:28660144

Cohort Size, Sex and Socio-Economic Status as Predictors of Success in Year 12 Physics in Perth, 1987-1997

ERIC Educational Resources Information Center

Geelan, David; Louden, William; Wildy, Helen

2013-01-01

A variety of factors are associated with students' achievement in secondary school physics, including cohort size--the total number of students studying Physics in the school--and socioeconomic status. Earlier studies also showed boys achieving better in Physics, while more recent research has shown better results for girls. Statistical analysis…

45 CFR 1620.5 - Annual review.

Code of Federal Regulations, 2014 CFR

2014-10-01

... number of emergency cases outside of its priorities. (b) The following factors should be among those... recipient; (3) Changes in the size, distribution, or needs of the eligible client population; and (4) The...

45 CFR 1620.5 - Annual review.

Code of Federal Regulations, 2012 CFR

2012-10-01

... number of emergency cases outside of its priorities. (b) The following factors should be among those... recipient; (3) Changes in the size, distribution, or needs of the eligible client population; and (4) The...

45 CFR 1620.5 - Annual review.

Code of Federal Regulations, 2013 CFR

2013-10-01

... number of emergency cases outside of its priorities. (b) The following factors should be among those... recipient; (3) Changes in the size, distribution, or needs of the eligible client population; and (4) The...

Wnt/Notum spatial feedback inhibition controls neoblast differentiation to regulate reversible growth of the planarian brain

PubMed Central

Hill, Eric M.; Petersen, Christian P.

2015-01-01

Mechanisms determining final organ size are poorly understood. Animals undergoing regeneration or ongoing adult growth are likely to require sustained and robust mechanisms to achieve and maintain appropriate sizes. Planarians, well known for their ability to undergo whole-body regeneration using pluripotent adult stem cells of the neoblast population, can reversibly scale body size over an order of magnitude by controlling cell number. Using quantitative analysis, we showed that after injury planarians perfectly restored brain:body proportion by increasing brain cell number through epimorphosis or decreasing brain cell number through tissue remodeling (morphallaxis), as appropriate. We identified a pathway controlling a brain size set-point that involves feedback inhibition between wnt11-6/wntA/wnt4a and notum, encoding conserved antagonistic signaling factors expressed at opposite brain poles. wnt11-6/wntA/wnt4a undergoes feedback inhibition through canonical Wnt signaling but is likely to regulate brain size in a non-canonical pathway independently of beta-catenin-1 and APC. Wnt/Notum signaling tunes numbers of differentiated brain cells in regenerative growth and tissue remodeling by influencing the abundance of brain progenitors descended from pluripotent stem cells, as opposed to regulating cell death. These results suggest that the attainment of final organ size might be accomplished by achieving a balance of positional signaling inputs that regulate the rates of tissue production. PMID:26525673

Heat and fluid flow characteristics of an oval fin-and-tube heat exchanger with large diameters for textile machine dryer

NASA Astrophysics Data System (ADS)

Bae, Kyung Jin; Cha, Dong An; Kwon, Oh Kyung

2016-11-01

The objectives of this paper are to develop correlations between heat transfer and pressure drop for oval finned-tube heat exchanger with large diameters (larger than 20 mm) used in a textile machine dryer. Numerical tests using ANSYS CFX are performed for four different parameters; tube size, fin pitch, transverse tube pitch and longitudinal tube pitch. The numerical results showed that the Nusselt number and the friction factor are in a range of -16.2 ~ +3.1 to -7.7 ~ +3.9 %, respectively, compared with experimental results. It was found that the Nusselt number linearly increased with increasing Reynolds number, but the friction factor slightly decreased with increasing Reynolds number. It was also found that the variation of longitudinal tube pitch has little effect on the Nusselt number and friction factor than other parameters (below 2.0 and 2.5 %, respectively). This study proposed a new Nusselt number and friction factor correlation of the oval finned-tube heat exchanger with large diameters for textile machine dryer.

Limits to sustained energy intake. XVII. Lactation performance in MF1 mice is not programmed by fetal number during pregnancy.

PubMed

Duah, Osei A; Monney, Kweku A; Hambly, Catherine; Król, Elzbieta; Speakman, John R

2013-06-15

Several studies have suggested that lactation performance may be programmed by the number of fetuses during pregnancy, whereas other studies indicate that processes during lactation are more important. As gestation litter size and litter size in lactation are usually strongly correlated, separating the roles of pregnancy and lactation in lactation performance is difficult. To break this link, we experimentally manipulated litter size of MF1 mice to five or 16 pups per litter by cross-fostering. Litter size and mass at birth were recorded on day 1 of lactation prior to litter size manipulation. Maternal body mass and food intake, litter size and litter mass were measured daily throughout. After weaning, the potential differential utilisation of body tissues of the mothers was investigated. Relationships between maternal mass and food intake, including asymptotic daily food intake at peak lactation, offspring traits and other maternal parameters suggested that the number of fetuses the females had carried during pregnancy had no effect on lactation performance. Litter mass increases depended only on maternal food intake, which was highly variable between individuals, but was independent of fetal litter size. The sizes of key organs and tissues like the liver and alimentary tract were not related to maximal food intake at peak lactation or to fetal litter size, but the masses of the pelage, mammary glands and retroperitoneal fat pad were. These data suggest that while growth of the mammary glands and associated structures may be initiated in gestation, and vary in relation to the number of placentas, the ultimate sizes and activities of the tissues depends primarily on factors during lactation.

Size-resolved particle emission factors for individual ships

NASA Astrophysics Data System (ADS)

Jonsson, Åsa M.; Westerlund, Jonathan; Hallquist, Mattias

2011-07-01

In these experiments size-resolved emission factors for particle number (EFPN) and mass (EFPM) have been determined for 734 individual ship passages for real-world dilution. The method used is an extractive sampling method of the passing ship plumes where particle number/mass and CO2 were measured with high time resolution (1 Hz). The measurements were conducted on a small island located in the entrance to the port of Gothenburg (N57.6849, E11.838), the largest harbor in Scandinavia. This is an emission control area (ECA) and in close vicinity to populated areas. The average EFPN and EFPM were 2.55 ± 0.11 × 1016 (kg fuel)-1 and 2050 ± 110 mg (kg fuel)-1, respectively. The determined EF for ships with multiple passages showed a great reproducibility. Size-resolved EFPN were peaking at small particle sizes ˜35 nm. Smaller particle sizes and hence less mass were observed by a gas turbine equipped ship compared to diesel engine equipped ships. On average 36 to 46% of the emitted particles by number were non-volatile and 24% by mass (EFPN 1.16 ± 0.19 × 1016 [kg fuel]-1 and EFPM 488 ± 73 mg [kg fuel]-1, respectively). This study shows a great potential to gain large data-sets regarding ship emission determining parameters that can improve current dispersion modeling for health assessments on local and regional scales. The global contributions of total and non-volatile particle mass from shipping using this extensive data-set from an ECA were estimated to be at least 0.80 Tgy-1 and 0.19 Tgy-1.

Role of insulin-like growth factor-I in the regulation of skeletal muscle adaptation to increased loading

NASA Technical Reports Server (NTRS)

Adams, G. R.

1998-01-01

Adaptations in muscle mass stimulated by changes in muscle loading state entail alternations in the synthesis and degradation of myofiber proteins and the modulation of myonuclear number such that the ratio between the number of myonuclei and the size of the myofibers remains relatively constant. As depicted schematically in Figure 2.6, the literature regarding the role of IGF-in mediating muscle adaptation to alterations in loading state suggests the following conclusions: During periods of increased loading, myofibers upregulate the expression and secretion of IGF-I. Acting as an autocrine and/or paracrine growth factor, IGF-I stimulates myofiber anabolic processes. Acting as a paracrine growth factor, IGF-I also stimulates adjacent satellite cells to enter the cell cycle and proliferate. Continued myofiber production of IGF-I stimulates some satellite cells to differentiate and then fuse with myofibers, thus providing additional myonuclei in order to maintain or reestablish the myonucleus to myofiber size ratios of the enlarged myofibers.

Determining the standoff distance of the bow shock: Mach number dependence and use of models

NASA Technical Reports Server (NTRS)

Farris, M. H.; Russell, C. T.

1994-01-01

We explore the factors that determine the bow shock standoff distance. These factors include the parameters of the solar wind, as well as the size and shape of the obstacle. In this report we develop a semiempirical Mach number relation for the bow shock standoff distance in order to take into account the shock's behavior at low Mach numbers. This is done by determining which properties of the shock are most important in controlling the standoff distance and using this knowledge to modify the current Mach number relation. While the present relation has proven useful at higher Mach numbers, it has lacked effectiveness at the low Mach number limit. We also analyze the bow shock dependence upon the size and shape of the obstacle, noting that it is most appropriate to compare the standoff distance of the bow shock to the radius of curvature of the obstacle, as opposed to the distance from the focus of the object to the nose. Last, we focus our attention on the use of bow shock models in determining the standoff distance. We note that the physical behavior of the shock must correctly be taken into account, specifically the behavior as a function of solar wind dynamic pressure; otherwise, erroneous results can be obtained for the bow shock standoff distance.

Lowering sample size in comparative analyses can indicate a correlation where there is none: example from Rensch's rule in primates.

PubMed

Lindenfors, P; Tullberg, B S

2006-07-01

The fact that characters may co-vary in organism groups because of shared ancestry and not always because of functional correlations was the initial rationale for developing phylogenetic comparative methods. Here we point out a case where similarity due to shared ancestry can produce an undesired effect when conducting an independent contrasts analysis. Under special circumstances, using a low sample size will produce results indicating an evolutionary correlation between characters where an analysis of the same pattern utilizing a larger sample size will show that this correlation does not exist. This is the opposite effect of increased sample size to that expected; normally an increased sample size increases the chance of finding a correlation. The situation where the problem occurs is when co-variation between the two continuous characters analysed is clumped in clades; e.g. when some phylogenetically conservative factors affect both characters simultaneously. In such a case, the correlation between the two characters becomes contingent on the number of clades sharing this conservative factor that are included in the analysis, in relation to the number of species contained within these clades. Removing species scattered evenly over the phylogeny will in this case remove the exact variation that diffuses the evolutionary correlation between the two characters - the variation contained within the clades sharing the conservative factor. We exemplify this problem by discussing a parallel in nature where the described problem may be of importance. This concerns the question of the presence or absence of Rensch's rule in primates.

Bias and Precision of Measures of Association for a Fixed-Effect Multivariate Analysis of Variance Model

ERIC Educational Resources Information Center

Kim, Soyoung; Olejnik, Stephen

2005-01-01

The sampling distributions of five popular measures of association with and without two bias adjusting methods were examined for the single factor fixed-effects multivariate analysis of variance model. The number of groups, sample sizes, number of outcomes, and the strength of association were manipulated. The results indicate that all five…

Some factors contributing to protein-energy malnutrition in the middle belt of Nigeria.

PubMed

Ighogboja, S I

1992-10-01

A number of risk factors leading to malnutrition were investigated among 400 mothers of malnourished children in the middle belt of Nigeria. Poverty, family instability, poor environmental sanitation, faulty weaning practices, illiteracy, ignorance, large family size and preventable infections are the main factors responsible for malnutrition. The strategies for intervention are in the area of health education emphasizing the importance of breastfeeding, family stability, responsible parenthood and small family sizes through culturally acceptable family planning methods. There is need to improve weaning methods through nutrition education, growth monitoring and food demonstration with community participation. Political will is needed to improve literacy status, farming methods and general living conditions.

Radiolucent rings around bioabsorbable anchors after rotator cuff repair are not associated with clinical outcomes.

PubMed

Park, Jin-Young; Jang, Suk-Hwan; Oh, Kyung-Soo; Li, Yi Jin

2017-11-01

Various researchers have observed small areas of osteolysis after using bioabsorbable anchors in shoulder surgeries. The purpose of this study is to determine whether radiographic perianchor radiolucent rings after rotator cuff repair are associated with the failure of repair and also assess their clinical implications. Further, the most frequent location of the radiolucent rings in the double-row suture bridge configuration was also assessed. One hundred and twenty-nine consecutive patients who underwent arthroscopic rotator cuff repair by suture bridge technique were retrospectively evaluated radiographically and clinically. The number and size of the rings that appeared at each follow-up were recorded. Also, the locations of each ring were recorded as anterior, middle or posterior, and medial or lateral according to the construct of the anchors used for suture bridge technique. The size of the tear, the number of anchors used and age of the patients were compared. Re-tear rates according to ultrasound examinations were also analyzed. After rotator cuff repair, the mean American Shoulder and Elbow Surgeons (ASES) score increased from 46.7 to 88.0 and the overall re-tear rate was 8.5% (11 cases). Seventy-three patients (56.6%) showed RR (total number of 99 rings) at least once during the course of their follow-up and the rings appeared at a mean period of 18.2 months after surgery. Mean size of the rings initially was 5.6 mm and the rings increased or decreased in mean size of 0.4 mm during mean follow-up of 37 months. No correlation was seen with the number of RRs and the rate of re-tears, number of anchors, size of tears, and clinical outcome as determined by the ASES score. Radiolucent ring measurement reproducibility was confirmed by independent, repeated measurements. The rings appeared mostly at anteromedial anchors (75 rings, 75.8%) and the authors suggest that mechanical factors may play a role for the cause of radiolucent rings. The number and the size of RRs around bioabsorbable anchors after rotator cuff repair do not appear to adversely affect the healing and clinical outcome of ARCR. Most radiolucent rings appeared at anteromedial anchors, indicating that mechanical factors may play a role for the radiolucencies. Case series, level IV.

Dog days of summer: Influences on decision of wolves to move pups

USGS Publications Warehouse

Ausband, David E.; Mitchell, Michael S.; Bassing, Sarah B.; Nordhagen, Matthew; Smith, Douglas W.; Stahler, Daniel R.

2016-01-01

For animals that forage widely, protecting young from predation can span relatively long time periods due to the inability of young to travel with and be protected by their parents. Moving relatively immobile young to improve access to important resources, limit detection of concentrated scent by predators, and decrease infestations by ectoparasites can be advantageous. Moving young, however, can also expose them to increased mortality risks (e.g., accidents, getting lost, predation). For group-living animals that live in variable environments and care for young over extended time periods, the influence of biotic factors (e.g., group size, predation risk) and abiotic factors (e.g., temperature and precipitation) on the decision to move young is unknown. We used data from 25 satellite-collared wolves ( Canis lupus ) in Idaho, Montana, and Yellowstone National Park to evaluate how these factors could influence the decision to move pups during the pup-rearing season. We hypothesized that litter size, the number of adults in a group, and perceived predation risk would positively affect the number of times gray wolves moved pups. We further hypothesized that wolves would move their pups more often when it was hot and dry to ensure sufficient access to water. Contrary to our hypothesis, monthly temperature above the 30-year average was negatively related to the number of times wolves moved their pups. Monthly precipitation above the 30-year average, however, was positively related to the amount of time wolves spent at pup-rearing sites after leaving the natal den. We found little relationship between risk of predation (by grizzly bears, humans, or conspecifics) or group and litter sizes and number of times wolves moved their pups. Our findings suggest that abiotic factors most strongly influence the decision of wolves to move pups, although responses to unpredictable biotic events (e.g., a predator encountering pups) cannot be ruled out.

Secular trends in impact factor of neonatology publications over a 10-year period.

PubMed

Marom, Ronella; Mimouni, Francis B; Cohen, Shlomi; Lubetzky, Ronit; Mandel, Dror

2012-10-01

  To test the hypotheses that published randomized clinical trials (RCTs) in neonatology with negative results (NR) are more likely to be published in journals with lower impact factor (IF) than those with positive results (PR); that there is an increase in the number of yearly published RCTs; that studies with large sample sizes are likely to be published in journals with higher IF.   We used all English-written RCTs registered in MEDLINE between 1/1/2001-31/12/2010 in the field of neonatology. Each RCT was classified as having a PR or NR. IF of each journal was determined for the year of publication.   We identified 329 RCTs. Yearly number of RCTs varied between 19 and 46, with no significant consistent linear increase over the years. There was no significant change over the years in average IF or in average patient size. IF and sample size of the studies were not significantly higher in studies with PR than in studies with NR.   The number of RCTs per year in the field of neonatology has stabilized in the past 10 years, and RCTs with positive or negative results are published in journals of similar IF. © 2012 The Author(s)/Acta Paediatrica © 2012 Foundation Acta Paediatrica.

Effects of Size and Age of the Host Musca domestica (Diptera: Muscidae) on Production of the Parasitoid Wasp Spalangia endius (Hymenoptera: Pteromalidae).

PubMed

Broski, Scott A; King, B H

2017-02-01

One method of control of house flies, Musca domestica L. (Diptera: Muscidae), and other filth flies is by repeated release of large numbers of pupal parasitoids such as Spalangia endius Walker. Rearing these parasitoids may be facilitated by understanding how host factors affect their production. Previous studies have examined the effects of host size and host age on parasitoid production, but have not examined the interaction between host size and host age or the effects with older females, which may be less capable of drilling tough hosts. Females were given hosts of a single size-age category (small young, small old, large young, or large old) for 2 wk. The effect of host size and of host age on parasitoid production depended on female age. On their first day of oviposition, females produced more offspring from large than from small hosts, but host age had no significant effect. The cumulative number of parasitoids produced in the first week was not significantly affected by host size or host age. However, the cumulative number of parasitoids produced over 2 wk was affected by both host size and host age, with the greatest number of parasitoids produced from small young hosts. Thus, not only are smaller hosts cheaper to produce, but these results suggest that their use may have no effect or a positive effect on the number of parasitoids that can be produced when females are ovipositing for a week or two. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Randomization in clinical trials: stratification or minimization? The HERMES free simulation software.

PubMed

Fron Chabouis, Hélène; Chabouis, Francis; Gillaizeau, Florence; Durieux, Pierre; Chatellier, Gilles; Ruse, N Dorin; Attal, Jean-Pierre

2014-01-01

Operative clinical trials are often small and open-label. Randomization is therefore very important. Stratification and minimization are two randomization options in such trials. The first aim of this study was to compare stratification and minimization in terms of predictability and balance in order to help investigators choose the most appropriate allocation method. Our second aim was to evaluate the influence of various parameters on the performance of these techniques. The created software generated patients according to chosen trial parameters (e.g., number of important prognostic factors, number of operators or centers, etc.) and computed predictability and balance indicators for several stratification and minimization methods over a given number of simulations. Block size and proportion of random allocations could be chosen. A reference trial was chosen (50 patients, 1 prognostic factor, and 2 operators) and eight other trials derived from this reference trial were modeled. Predictability and balance indicators were calculated from 10,000 simulations per trial. Minimization performed better with complex trials (e.g., smaller sample size, increasing number of prognostic factors, and operators); stratification imbalance increased when the number of strata increased. An inverse correlation between imbalance and predictability was observed. A compromise between predictability and imbalance still has to be found by the investigator but our software (HERMES) gives concrete reasons for choosing between stratification and minimization; it can be downloaded free of charge. This software will help investigators choose the appropriate randomization method in future two-arm trials.

Exploring Fundamental Concepts in Aqueous Solution Conductivity: A General Chemistry Laboratory Exercise

ERIC Educational Resources Information Center

Nyasulu, Frazier; Stevanov, Kelly; Barlag, Rebecca

2010-01-01

Using a conductivity sensor, a temperature sensor, and a datalogger, fundamental factors that affect conductivity are explored. These factors are (i) concentration, (ii) temperature, (iii) ion charge, and (iv) size and or mass of anion. In addition, the conductivities of a number of other solutions are measured. This lab has been designed to…

Southwest Hispanic Community -- The Absence of Homeland Security Threats

DTIC Science & Technology

2012-12-01

The capacity to act collectively is based upon internal environmental factors, such as leadership, level of available resources, group size, and...degree of internal organization. External environmental factors include the level of societal repression, extent of external sympathizers and number and...states: California (Mexicans, Salvadorans and Guatemalans), Florida (Cubans, Colombians , Hondurans and Peruvians) or New York (Puerto Ricans

Factors Leading to Retention of School Librarian Positions: A School District Case Study

ERIC Educational Resources Information Center

Ewbank, Ann Dutton

2010-01-01

In the past five years, the number of school librarians has greatly diminished despite valiant advocacy efforts by librarians, parents, and state and national library associations. This descriptive case study investigated the factors that led governing board members in a mid-sized urban high school district to retain certified school librarian…

The Effect of Viewing Eccentricity on Enumeration

PubMed Central

Palomares, Melanie; Smith, Paul R.; Pitts, Carole Holley; Carter, Breana M.

2011-01-01

Visual acuity and contrast sensitivity progressively diminish with increasing viewing eccentricity. Here we evaluated how visual enumeration is affected by visual eccentricity, and whether subitizing capacity, the accurate enumeration of a small number (∼3) of items, decreases with more eccentric viewing. Participants enumerated gratings whose (1) stimulus size was constant across eccentricity, and (2) whose stimulus size scaled by a cortical magnification factor across eccentricity. While we found that enumeration accuracy and precision decreased with increasing eccentricity, cortical magnification scaling of size neutralized the deleterious effects of increasing eccentricity. We found that size scaling did not affect subitizing capacities, which were nearly constant across all eccentricities. We also found that size scaling modulated the variation coefficients, a normalized metric of enumeration precision, defined as the standard deviation divided by the mean response. Our results show that the inaccuracy and imprecision associated with increasing viewing eccentricity is due to limitations in spatial resolution. Moreover, our results also support the notion that the precise number system is restricted to small numerosities (represented by the subitizing limit), while the approximate number system extends across both small and large numerosities (indexed by variation coefficients) at large eccentricities. PMID:21695212

The effect of viewing eccentricity on enumeration.

PubMed

Palomares, Melanie; Smith, Paul R; Pitts, Carole Holley; Carter, Breana M

2011-01-01

Visual acuity and contrast sensitivity progressively diminish with increasing viewing eccentricity. Here we evaluated how visual enumeration is affected by visual eccentricity, and whether subitizing capacity, the accurate enumeration of a small number (∼3) of items, decreases with more eccentric viewing. Participants enumerated gratings whose (1) stimulus size was constant across eccentricity, and (2) whose stimulus size scaled by a cortical magnification factor across eccentricity. While we found that enumeration accuracy and precision decreased with increasing eccentricity, cortical magnification scaling of size neutralized the deleterious effects of increasing eccentricity. We found that size scaling did not affect subitizing capacities, which were nearly constant across all eccentricities. We also found that size scaling modulated the variation coefficients, a normalized metric of enumeration precision, defined as the standard deviation divided by the mean response. Our results show that the inaccuracy and imprecision associated with increasing viewing eccentricity is due to limitations in spatial resolution. Moreover, our results also support the notion that the precise number system is restricted to small numerosities (represented by the subitizing limit), while the approximate number system extends across both small and large numerosities (indexed by variation coefficients) at large eccentricities.

Small-angle scattering from 3D Sierpinski tetrahedron generated using chaos game

NASA Astrophysics Data System (ADS)

Slyamov, Azat

2017-12-01

We approximate a three dimensional version of deterministic Sierpinski gasket (SG), also known as Sierpinski tetrahedron (ST), by using the chaos game representation (CGR). Structural properties of the fractal, generated by both deterministic and CGR algorithms are determined using small-angle scattering (SAS) technique. We calculate the corresponding monodisperse structure factor of ST, using an optimized Debye formula. We show that scattering from CGR of ST recovers basic fractal properties, such as fractal dimension, iteration number, scaling factor, overall size of the system and the number of units composing the fractal.

Genetic and epigenetic contributions to the cortical phenotype in mammals☆

PubMed Central

Larsen, DeLaine D.; Krubitzer, Leah

2008-01-01

One aspect of cortical organization, cortical field size, is variable both within and across species. The observed variability arises from a variety of sources, including genes intrinsic to the neocortex and a number of extrinsic and epigenetic factors. Genes intrinsic to the cortex are directly involved in the development and specification of cortical fields and are regulated from both signaling centers located outside of the neocortex, which secrete diffusible molecules, and the expression of transcription factors within the neocortex. In addition, extrinsic factors such as the type, location and density of sensory receptor arrays and how these receptor arrays are utilized, are also strongly related to cortical field size. Epigenetic factors including the relative activity patterns generated by the different types of physical stimuli in a given environment also contribute to differences in cortical organization, including cortical field size. Since both genetic and epigenetic factors contribute to cortical organization, some aspects of the cortical phenotype evolve, while other aspects of the cortical phenotype persist only if the environment in which an individual develops is relatively stable. PMID:18331904

Preoperative predictive factors for gallbladder cholesterol polyp diagnosed after laparoscopic cholecystectomy for polypoid lesions of gallbladder

PubMed Central

Lee, Hyojin; Park, Inseok; Cho, Hyunjin; Gwak, Geumhee; Yang, Keunho; Bae, Byung-Noe; Kim, Hong-Ju; Kim, Young Duk

2016-01-01

Backgrounds/Aims We investigated patients' clinical and radiological data to determine preoperative factors that predict cholesterol gallbladder (GB) polyps of large size, which can be helpful for decision on further diagnostic tools. Methods In this study, we retrospectively analyzed 126 patients who underwent laparoscopic cholecystectomy for GB polyps >10 mm diagnosed preoperatively by abdominal ultrasonography between February 2002 and February 2016 in Department of Surgery, Sanggye Paik Hospital. Patients were divided into non-cholesterol polyps group and cholesterol polyps group, based on the postoperative pathologic diagnosis. Clinical and radiological data, such as gender, age, body weight, height, body mass index (BMI), laboratory findings, size, number and shape of the polypoid lesions, and presence of the concurrent GB stone were compared between the two groups. Results Of the 126 cases, 73 had cholesterol polyps (57.9%) and 53 cases were non-cholesterol polyps (42.1%). The younger age (<48.5 years), size of polyp <13.25 mm and multiple polyps were independent predictive variables for cholesterol polyps, with odd ratios (OR) of 2.352 (p=0.045), 5.429 (p<0.001) and 0.472 (p<0.001), respectively. Conclusions Age, size and polyp number were used to predict cholesterol GB polyp among polypoid lesions of the gallbladder >10 mm. For cases in which these factors are not applicable, it is strongly recommended to evaluate further diagnostic tools, such as computed tomography, endoscopic ultrasonography and tumor markers. PMID:28261697

A simulation study of the strength of evidence in the recommendation of medications based on two trials with statistically significant results

PubMed Central

Ioannidis, John P. A.

2017-01-01

A typical rule that has been used for the endorsement of new medications by the Food and Drug Administration is to have two trials, each convincing on its own, demonstrating effectiveness. “Convincing” may be subjectively interpreted, but the use of p-values and the focus on statistical significance (in particular with p < .05 being coined significant) is pervasive in clinical research. Therefore, in this paper, we calculate with simulations what it means to have exactly two trials, each with p < .05, in terms of the actual strength of evidence quantified by Bayes factors. Our results show that different cases where two trials have a p-value below .05 have wildly differing Bayes factors. Bayes factors of at least 20 in favor of the alternative hypothesis are not necessarily achieved and they fail to be reached in a large proportion of cases, in particular when the true effect size is small (0.2 standard deviations) or zero. In a non-trivial number of cases, evidence actually points to the null hypothesis, in particular when the true effect size is zero, when the number of trials is large, and when the number of participants in both groups is low. We recommend use of Bayes factors as a routine tool to assess endorsement of new medications, because Bayes factors consistently quantify strength of evidence. Use of p-values may lead to paradoxical and spurious decision-making regarding the use of new medications. PMID:28273140

Pupil size directly modulates the feedforward response in human primary visual cortex independently of attention.

PubMed

Bombeke, Klaas; Duthoo, Wout; Mueller, Sven C; Hopf, Jens-Max; Boehler, C Nico

2016-02-15

Controversy revolves around the question of whether psychological factors like attention and emotion can influence the initial feedforward response in primary visual cortex (V1). Although traditionally, the electrophysiological correlate of this response in humans (the C1 component) has been found to be unaltered by psychological influences, a number of recent studies have described attentional and emotional modulations. Yet, research into psychological effects on the feedforward V1 response has neglected possible direct contributions of concomitant pupil-size modulations, which are known to also occur under various conditions of attentional load and emotional state. Here we tested the hypothesis that such pupil-size differences themselves directly affect the feedforward V1 response. We report data from two complementary experiments, in which we used procedures that modulate pupil size without differences in attentional load or emotion while simultaneously recording pupil-size and EEG data. Our results confirm that pupil size indeed directly influences the feedforward V1 response, showing an inverse relationship between pupil size and early V1 activity. While it is unclear in how far this effect represents a functionally-relevant adaptation, it identifies pupil-size differences as an important modulating factor of the feedforward response of V1 and could hence represent a confounding variable in research investigating the neural influence of psychological factors on early visual processing. Copyright © 2015 Elsevier Inc. All rights reserved.

The abundance of compact quiescent galaxies since z ˜ 0.6

NASA Astrophysics Data System (ADS)

Charbonnier, Aldée; Huertas-Company, Marc; Gonçalves, Thiago S.; Menéndez-Delmestre, Karín; Bundy, Kevin; Galliano, Emmanuel; Moraes, Bruno; Makler, Martín; Pereira, Maria E. S.; Erben, Thomas; Hildebrandt, Hendrik; Shan, Huan-Yuan; Caminha, Gabriel B.; Grossi, Marco; Riguccini, Laurie

2017-08-01

We set out to quantify the number density of quiescent massive compact galaxies at intermediate redshifts. We determine structural parameters based on I-band imaging using the Canada-France-Hawaii Telescope (CFHT) equatorial Sloan Digital Sky Survey (SDSS) Stripe 82 (CS82) survey (˜170 deg2) taking advantage of an exquisite median seeing of ˜0.6 arcsec. We select compact massive (M⋆ > 5 × 1010 M⊙) galaxies within the redshift range of 0.2 < z < 0.6. The large volume sampled allows to decrease the effect of cosmic variance that has hampered the calculation of the number density for this enigmatic population in many previous studies. We undertake an exhaustive analysis in an effort to untangle the various findings inherent to the diverse definition of compactness present in the literature. We find that the absolute number of compact galaxies is very dependent on the adopted definition and can change up to a factor of >10. We systematically measure a factor of ˜5 more compacts at the same redshift than what was previously reported on smaller fields with Hubble Space Telescope (HST) imaging, which are more affected by cosmic variance. This means that the decrease in number density from z ˜ 1.5 to z ˜ 0.2 might be only of a factor of ˜2-5, significantly smaller than what was previously reported. This supports progenitor bias as the main contributor to the size evolution. This milder decrease is roughly compatible with the predictions from recent numerical simulations. Only the most extreme compact galaxies, with Reff < 1.5 × (M⋆/1011 M⊙)0.75 and M⋆ > 1010.7 M⊙, appear to drop in number by a factor of ˜20 and hence likely experience a noticeable size evolution.

Assessing the leaning, bending, and sinuosity of sapling-size trees

Treesearch

Daniel J. Leduc; Shi-Jean S. Sung; Kristi Wharton

2012-01-01

Many factors result in trees with non-straight stems. An important prerequisite to investigating the causes of stem deformity is an ability to assess stem displacement. An ideal system would be easy to implement, be objective, and result in an index that incorporates the essential characteristics of the stem deformity into a dimensionless number. We tested a number of...

Flat-topped beam transmittance in anisotropic non-Kolmogorov turbulent marine atmosphere

NASA Astrophysics Data System (ADS)

Ata, Yalçın; Baykal, Yahya

2017-10-01

Turbulence affects optical propagation, and, as a result, the intensity is attenuated along the path of propagation. The attenuation becomes significant when the turbulence becomes stronger. Transmittance is a measure indicating how much power is collected at the receiver after the optical wave propagates in the turbulent medium. The on-axis transmittance is formulated when a flat-topped optical beam propagates in a marine atmosphere experiencing anisotropic non-Kolmogorov turbulence. Variations in the transmittance are evaluated versus the beam source size, beam number, link distance, power law exponent, anisotropy factor, and structure constant. It is found that larger beam source sizes and beam numbers yield higher transmittance values; however, as the link distance, power law exponent, anisotropy factor, or structure constant increase, transmittance values are lowered. Our results will help in the performance evaluations of optical wireless communication and optical imaging systems operating in a marine atmosphere.

Problems associated with using filtration to define dissolved trace element concentrations in natural water samples

USGS Publications Warehouse

Horowitz, A.J.; Lum, K.R.; Garbarino, J.R.; Hall, G.E.M.; Lemieux, C.; Demas, C.R.

1996-01-01

Field and laboratory experiments indicate that a number of factors associated with filtration other than just pore size (e.g., diameter, manufacturer, volume of sample processed, amount of suspended sediment in the sample) can produce significant variations in the 'dissolved' concentrations of such elements as Fe, Al, Cu, Zn, Pb, Co, and Ni. The bulk of these variations result from the inclusion/exclusion of colloidally associated trace elements in the filtrate, although dilution and sorption/desorption from filters also may be factors. Thus, dissolved trace element concentrations quantitated by analyzing filtrates generated by processing whole water through similar pore-sized filters may not be equal or comparable. As such, simple filtration of unspecified volumes of natural water through unspecified 0.45-??m membrane filters may no longer represent an acceptable operational definition for a number of dissolved chemical constituents.

Metroticket 2.0 Model for Analysis of Competing Risks of Death After Liver Transplantation for Hepatocellular Carcinoma.

PubMed

Mazzaferro, Vincenzo; Sposito, Carlo; Zhou, Jian; Pinna, Antonio D; De Carlis, Luciano; Fan, Jia; Cescon, Matteo; Di Sandro, Stefano; Yi-Feng, He; Lauterio, Andrea; Bongini, Marco; Cucchetti, Alessandro

2018-01-01

Outcomes of liver transplantation for hepatocellular carcinoma (HCC) are determined by cancer-related and non-related events. Treatments for hepatitis C virus infection have reduced non-cancer events among patients receiving liver transplants, so reducing HCC-related death might be an actionable end point. We performed a competing-risk analysis to evaluate factors associated with survival of patients with HCC and developed a prognostic model based on features of HCC patients before liver transplantation. We performed multivariable competing-risk regression analysis to identify factors associated with HCC-specific death of patients who underwent liver transplantation. The training set comprised 1018 patients who underwent liver transplantation for HCC from January 2000 through December 2013 at 3 tertiary centers in Italy. The validation set comprised 341 consecutive patients who underwent liver transplantation for HCC during the same period at the Liver Cancer Institute in Shanghai, China. We collected pretransplantation data on etiology of liver disease, number and size of tumors, patient level of α-fetoprotein (AFP), model for end-stage liver disease score, tumor stage, numbers and types of treatment, response to treatments, tumor grade, microvascular invasion, dates, and causes of death. Death was defined as HCC-specific when related to HCC recurrence after transplantation, disseminated extra- and/or intrahepatic tumor relapse and worsened liver function in presence of tumor spread. The cumulative incidence of death was segregated for hepatitis C virus status. In the competing-risk regression, the sum of tumor number and size and of log 10 level of AFP were significantly associated with HCC-specific death (P < .001), returning an average c-statistic of 0.780 (95% confidence interval, 0.763-0.798). Five-year cumulative incidence of non-HCC-related death was 8.6% in HCV-negative patients and 18.1% in HCV-positive patients. For patients with HCC to have a 70% chance of HCC-specific survival 5 years after transplantation, their level of AFP should be <200 ng/mL and the sum of number and size of tumors (in centimeters) should not exceed 7; if the level of AFP was 200-400 ng/mL, the sum of the number and size of tumors should be ≤5; if their level of AFP was 400-1000 ng/mL, the sum of the number and size of tumors should be ≤4. In the validation set, the model identified patients who survived 5 years after liver transplantation with 0.721 accuracy (95% confidence interval, 0.648%-0.793%). Our model, based on patients' level of AFP and HCC number and size, outperformed the Milan; University of California, San Francisco; Shanghai-Fudan; Up-to-7 criteria (P < .001); and AFP French model (P = .044) to predict which patients will survive for 5 years after liver transplantation. We developed a model based on level of AFP, tumor size, and tumor number, to determine risk of death from HCC-related factors after liver transplantation. This model might be used to select end points and refine selection criteria for liver transplantation for patients with HCC. To predict 5-year survival and risk of HCC-related death using an online calculator, please see www.hcc-olt-metroticket.org/. ClinicalTrials.gov ID NCT02898415. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Body mass index is an independent risk factor for the development of endometrial polyps in patients undergoing in vitro fertilization.

PubMed

Onalan, Reside; Onalan, Gogsen; Tonguc, Esra; Ozdener, Tulin; Dogan, Muammer; Mollamahmutoglu, Leyla

2009-04-01

To determine the subgroup of patients in whom office hysteroscopy should be routinely performed before an in vitro fertilization (IVF) program. Retrospective cohort analysis. Tertiary education and research hospital. Two hundred twenty-three patients who underwent a uterine evaluation by office hysteroscopy before the IVF and embryo transfer cycle. The office hysteroscopy was performed in the follicular phase of the menstrual cycle before the IVF cycle. The office findings: number of polyps, number of multiple polyps, and polyp size. Patients with polycystic ovary syndrome (PCOS) had a higher number of endometrial polyps, but the difference was not statistically significant (28.9% vs. 18.3%). When comparing the patients according to BMI, patients with BMI >or=30 had a statistically significantly higher number of endometrial polyps versus BMI <30 (52% vs. 15%). On the other hand, obesity was positively correlated with the occurrence of polyps, size of the polyps, and occurrence of multiple number of polyps in the correlation analysis. In addition, logistic regression analysis using age, obesity, duration of infertility, and estradiol levels revealed that obesity was an independent prognostic factor for the development of endometrial polyps. Office hysteroscopy should be performed in patients with BMI >or=30 because obesity may act as an initiator for the pathogenesis of endometrial polyps.

Influence of local meshing size on stress intensity factor of orthopedic lag screw

NASA Astrophysics Data System (ADS)

Husain, M. N.; Daud, R.; Basaruddin, K. S.; Mat, F.; Bajuri, M. Y.; Arifin, A. K.

2017-09-01

Linear elastic fracture mechanics (LEFM) concept is generally used to study the influence of crack on the performance of structures. In order to study the LEFM concept on damaged structure, the usage of finite element analysis software is implemented to do the simulation of the structure. Mesh generation is one of the most crucial procedures in finite element method. For the structure that crack or damaged, it is very important to determine the accurate local meshing size at the crack tip of the crack itself in order to get the accurate value of stress intensity factor, KI. Pre crack will be introduced to the lag screw based on the von mises' stress result that had been performed in previous research. This paper shows the influence of local mesh arrangement on numerical value of the stress intensity factor, KI obtained by the displacement method. This study aims to simulate the effect of local meshing which is the singularity region on stress intensity factor, KI to the critical point of failure in screw. Five different set of wedges meshing size are introduced during the simulation of finite element analysis. The number of wedges used to simulate this research is 8, 10, 14, 16 and 20. There are three set of numerical equations used to validate the results which are brown and srawley, gross and brown and Tada equation. The result obtained from the finite element software (ANSYS APDL) has a positive agreement with the numerical analysis which is Brown and Srawley compared to other numerical formula. Radius of first row size of 0.014 and singularity element with 14 numbers of wedges is proved to be the best local meshing for this study.

Factors affecting the palpability of breast lesion by self-examination.

PubMed

Lam, W W M; Chan, C P; Chan, C F; Mak, C C C; Chan, C F; Chong, K W H; Leung, M H J; Tang, M H

2008-03-01

This study aims to assess the accuracy of detection of breast lesion by breast self-examination and to assess different factors affecting the accuracy. All consecutive Chinese female patients, who attended our breast imaging unit in 2001, completed our questionnaire, had retrievable hard copy films, and had more than three years clinical follow-up, were recruited for this study. Different factors, such as age, menopausal status, previous experience of breastfeeding, family history of breast cancer, previous history of mastectomy or lumpectomy, hormonal therapy, oral contraceptive pills and previous history of mammography, were correlated with accuracy in self-detection of breast lesions retrospectively. The nature, size and location of the lesion, and breast size based on imaging, were also correlated with the accuracy in self-detection of breast lesions. A total of 163 questionnaires were analysed. 111 patients detected a breast lesion themselves and 24 of these lesions were false-positives. A total of 173 lesions (27 cancerous, 146 benign lesions) were documented by either ultrasonography and/or mammography, and confirmed by either histology or three-year clinical follow-up. The overall sensitivity in detecting both benign and malignant breast lesions was 71% when number of breast lesions was used as the denominator, and up to 78% sensitivity was achieved when number of patients was used as the denominator. History of mastectomy, and size and nature of the lesions were found to affect the accuracy of self-detection of breast lesions. Overall, breast self-examinations were effective in the detection of breast lesions and factors such as size of lesion, nature of the lesion and history of mastectomy affect the accuracy of the detections. Breast self-examination should be promoted for early detection of breast cancer.

The neural bases of the multiplication problem-size effect across countries

PubMed Central

Prado, Jérôme; Lu, Jiayan; Liu, Li; Dong, Qi; Zhou, Xinlin; Booth, James R.

2013-01-01

Multiplication problems involving large numbers (e.g., 9 × 8) are more difficult to solve than problems involving small numbers (e.g., 2 × 3). Behavioral research indicates that this problem-size effect might be due to different factors across countries and educational systems. However, there is no neuroimaging evidence supporting this hypothesis. Here, we compared the neural correlates of the multiplication problem-size effect in adults educated in China and the United States. We found a greater neural problem-size effect in Chinese than American participants in bilateral superior temporal regions associated with phonological processing. However, we found a greater neural problem-size effect in American than Chinese participants in right intra-parietal sulcus (IPS) associated with calculation procedures. Therefore, while the multiplication problem-size effect might be a verbal retrieval effect in Chinese as compared to American participants, it may instead stem from the use of calculation procedures in American as compared to Chinese participants. Our results indicate that differences in educational practices might affect the neural bases of symbolic arithmetic. PMID:23717274

Egg number-egg size: an important trade-off in parasite life history strategies.

PubMed

Cavaleiro, Francisca I; Santos, Maria J

2014-03-01

Parasites produce from just a few to many eggs of variable size, but our understanding of the factors driving variation in these two life history traits at the intraspecific level is still very fragmentary. This study evaluates the importance of performing multilevel analyses on egg number and egg size, while characterising parasite life history strategies. A total of 120 ovigerous females of Octopicola superba (Copepoda: Octopicolidae) (one sample (n=30) per season) were characterised with respect to different body dimensions (total length; genital somite length) and measures of reproductive effort (fecundity; mean egg diameter; total reproductive effort; mean egg sac length). While endoparasites are suggested to follow both an r- and K-strategy simultaneously, the evidence found in this and other studies suggests that environmental conditions force ectoparasites into one of the two alternatives. The positive and negative skewness of the distributions of fecundity and mean egg diameter, respectively, suggest that O. superba is mainly a K-strategist (i.e. produces a relatively small number of large, well provisioned eggs). Significant sample differences were recorded concomitantly for all body dimensions and measures of reproductive effort, while a general linear model detected a significant influence of season*parasite total length in both egg number and size. This evidence suggests adaptive phenotypic plasticity in body dimensions and size-mediated changes in egg production. Seasonal changes in partitioning of resources between egg number and size resulted in significant differences in egg sac length but not in total reproductive effort. Evidence for a trade-off between egg number and size was found while controlling for a potential confounding effect of parasite total length. However, this trade-off became apparent only at high fecundity levels, suggesting a state of physiological exhaustion. Copyright © 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

The influence of cutting-bill requirements on lumber yield using a fractional-factorial design part II, correlation and number of part sizes

Treesearch

Urs Buehlmann; D. Earl Kline; Janice K. Wiedenbeck; R., Jr. Noble

2008-01-01

Cutting-bill requirements, among other factors, influence the yield obtained when cutting lumber into parts. The first part of this 2-part series described how different cutting-bill part sizes, when added to an existing cutting-bill, affect lumber yield, and quantified these observations. To accomplish this, the study employed linear least squares estimation technique...

[The effect of the intratracheal administration of americium-241 on rat alveolar macrophages].

PubMed

Shopova, V; Sŭlovski, P; Dancheva, V

1996-01-01

In experiments in rats it was found that 241Am transitory decreases the total cell number and alveolar macrophage's percentage in bronchoalveolar lavage fluid (BALF): increases the macrophages size and nuclear size; and increases acid phosphatase and lactate dehydrogenase activities in BALF. It was suggested that 241Am causes and activation in the alveolar macrophages which probably appears as one of factors provoking lung injuries.

A resource for the assessment of lung nodule size estimation methods: database of thoracic CT scans of an anthropomorphic phantom◊

PubMed Central

Gavrielides, Marios A.; Kinnard, Lisa M.; Myers, Kyle J.; Peregoy, Jennifer; Pritchard, William F.; Zeng, Rongping; Esparza, Juan; Karanian, John; Petrick, Nicholas

2010-01-01

A number of interrelated factors can affect the precision and accuracy of lung nodule size estimation. To quantify the effect of these factors, we have been conducting phantom CT studies using an anthropomorphic thoracic phantom containing a vasculature insert to which synthetic nodules were inserted or attached. Ten repeat scans were acquired on different multi-detector scanners, using several sets of acquisition and reconstruction protocols and various nodule characteristics (size, shape, density, location). This study design enables both bias and variance analysis for the nodule size estimation task. The resulting database is in the process of becoming publicly available as a resource to facilitate the assessment of lung nodule size estimation methodologies and to enable comparisons between different methods regarding measurement error. This resource complements public databases of clinical data and will contribute towards the development of procedures that will maximize the utility of CT imaging for lung cancer screening and tumor therapy evaluation. PMID:20640011

Repeated Habitat Disturbances by Fire Decrease Local Effective Population Size

PubMed Central

Ragsdale, Alexandria K.; McCoy, Earl D.; Mushinsky, Henry R.

2016-01-01

Effective population size is a fundamental parameter in population genetics, and factors that alter effective population size will shape the genetic characteristics of populations. Habitat disturbance may have a large effect on genetic characteristics of populations by influencing immigration and gene flow, particularly in fragmented habitats. We used the Florida Sand Skink (Plestiodon reynoldsi) to investigate the effect of fire-based habitat disturbances on the effective population size in the highly threatened, severely fragmented, and fire dependent Florida scrub habitat. We screened 7 microsatellite loci in 604 individuals collected from 12 locations at Archbold Biological Station. Archbold Biological Station has an active fire management plan and detailed records of fires dating to 1967. Our objective was to determine how the timing, number, and intervals between fires affect effective population size, focusing on multiple fires in the same location. Effective population size was higher in areas that had not been burned for more than 10 years and decreased with number of fires and shorter time between fires. A similar pattern was observed in abundance: increasing abundance with time-since-fire and decreasing abundance with number of fires. The ratio of effective population size to census size was higher at sites with more recent fires and tended to decrease with time-since-last-fire. These results suggest that habitat disturbances, such as fire, may have a large effect in the genetic characteristics of local populations and that Florida Sand Skinks are well adapted to the natural fire dynamics required to maintain Florida scrub. PMID:26976940

WIDE AND THICK GRAIN 1, which encodes an otubain-like protease with deubiquitination activity, influences grain size and shape in rice.

PubMed

Huang, Ke; Wang, Dekai; Duan, Penggen; Zhang, Baolan; Xu, Ran; Li, Na; Li, Yunhai

2017-09-01

Grain size and shape are two crucial traits that influence grain yield and grain appearance in rice. Although several factors that affect grain size have been described in rice, the molecular mechanisms underlying the determination of grain size and shape are still elusive. In this study we report that WIDE AND THICK GRAIN 1 (WTG1) functions as an important factor determining grain size and shape in rice. The wtg1-1 mutant exhibits wide, thick, short and heavy grains and also shows an increased number of grains per panicle. WTG1 determines grain size and shape mainly by influencing cell expansion. WTG1 encodes an otubain-like protease, which shares similarity with human OTUB1. Biochemical analyses indicate that WTG1 is a functional deubiquitinating enzyme, and the mutant protein (wtg1-1) loses this deubiquitinating activity. WTG1 is expressed in developing grains and panicles, and the GFP-WTG1 fusion protein is present in the nucleus and cytoplasm. Overexpression of WTG1 results in narrow, thin, long grains due to narrow and long cells, further supporting the role of WTG1 in determining grain size and shape. Thus, our findings identify the otubain-like protease WTG1 to be an important factor that determines grain size and shape, suggesting that WTG1 has the potential to improve grain size and shape in rice. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Factors Affecting the Adoption of R&D Project Selection Techniques at the Air Force Wright Aeronautical Laboratories

DTIC Science & Technology

1988-09-01

tested. To measure 42 the adequacy of the sample, the Kaiser - Meyer - Olkin measure of sampling adequacy was used. This technique is described in Factor...40 4- 0 - 7 0 0 07 -58d the relatively large number of variables, there was concern about the adequacy of the sample size. A Kaiser - Meyer - Olkin

Open Online System Adoption in K-12 as a Democratising Factor

ERIC Educational Resources Information Center

Kimmons, Royce

2015-01-01

This study seeks to understand how district size and wealth factors influence the adoption of open-source online systems in primary and secondary (K-12) education. Most schools now utilise online systems (e.g. CMS, LMS, SIS) for a number of purposes, and it is anticipated that no-cost and open-source systems could be of great value for…

Values-Oriented Factors Leading to Retention of School Librarian Positions: A School District Case Study

ERIC Educational Resources Information Center

Ewbank, Ann Dutton

2011-01-01

The number of U.S. school librarians has greatly diminished despite advocacy efforts on the local and national level. This case study investigated the factors that led governing board members in a mid-size urban high school district to retain certified school librarian positions despite a major economic crisis. Data were collected through school…

Unsymmetric ordering using a constrained Markowitz scheme

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

Amestoy, Patrick R.; Xiaoye S.; Pralet, Stephane

2005-01-18

We present a family of ordering algorithms that can be used as a preprocessing step prior to performing sparse LU factorization. The ordering algorithms simultaneously achieve the objectives of selecting numerically good pivots and preserving the sparsity. We describe the algorithmic properties and challenges in their implementation. By mixing the two objectives we show that we can reduce the amount of fill-in in the factors and reduce the number of numerical problems during factorization. On a set of large unsymmetric real problems, we obtained the median reductions of 12% in the factorization time, of 13% in the size of themore » LU factors, of 20% in the number of operations performed during the factorization phase, and of 11% in the memory needed by the multifrontal solver MA41-UNS. A byproduct of this ordering strategy is an incomplete LU-factored matrix that can be used as a preconditioner in an iterative solver.« less

ORACLE INEQUALITIES FOR THE LASSO IN THE COX MODEL

PubMed Central

Huang, Jian; Sun, Tingni; Ying, Zhiliang; Yu, Yi; Zhang, Cun-Hui

2013-01-01

We study the absolute penalized maximum partial likelihood estimator in sparse, high-dimensional Cox proportional hazards regression models where the number of time-dependent covariates can be larger than the sample size. We establish oracle inequalities based on natural extensions of the compatibility and cone invertibility factors of the Hessian matrix at the true regression coefficients. Similar results based on an extension of the restricted eigenvalue can be also proved by our method. However, the presented oracle inequalities are sharper since the compatibility and cone invertibility factors are always greater than the corresponding restricted eigenvalue. In the Cox regression model, the Hessian matrix is based on time-dependent covariates in censored risk sets, so that the compatibility and cone invertibility factors, and the restricted eigenvalue as well, are random variables even when they are evaluated for the Hessian at the true regression coefficients. Under mild conditions, we prove that these quantities are bounded from below by positive constants for time-dependent covariates, including cases where the number of covariates is of greater order than the sample size. Consequently, the compatibility and cone invertibility factors can be treated as positive constants in our oracle inequalities. PMID:24086091

ORACLE INEQUALITIES FOR THE LASSO IN THE COX MODEL.

PubMed

Huang, Jian; Sun, Tingni; Ying, Zhiliang; Yu, Yi; Zhang, Cun-Hui

2013-06-01

We study the absolute penalized maximum partial likelihood estimator in sparse, high-dimensional Cox proportional hazards regression models where the number of time-dependent covariates can be larger than the sample size. We establish oracle inequalities based on natural extensions of the compatibility and cone invertibility factors of the Hessian matrix at the true regression coefficients. Similar results based on an extension of the restricted eigenvalue can be also proved by our method. However, the presented oracle inequalities are sharper since the compatibility and cone invertibility factors are always greater than the corresponding restricted eigenvalue. In the Cox regression model, the Hessian matrix is based on time-dependent covariates in censored risk sets, so that the compatibility and cone invertibility factors, and the restricted eigenvalue as well, are random variables even when they are evaluated for the Hessian at the true regression coefficients. Under mild conditions, we prove that these quantities are bounded from below by positive constants for time-dependent covariates, including cases where the number of covariates is of greater order than the sample size. Consequently, the compatibility and cone invertibility factors can be treated as positive constants in our oracle inequalities.

New Genes and New Insights from Old Genes: Update on Alzheimer Disease

PubMed Central

Ringman, John M.; Coppola, Giovanni

2013-01-01

Purpose of Review: This article discusses the current status of knowledge regarding the genetic basis of Alzheimer disease (AD) with a focus on clinically relevant aspects. Recent Findings: The genetic architecture of AD is complex, as it includes multiple susceptibility genes and likely nongenetic factors. Rare but highly penetrant autosomal dominant mutations explain a small minority of the cases but have allowed tremendous advances in understanding disease pathogenesis. The identification of a strong genetic risk factor, APOE, reshaped the field and introduced the notion of genetic risk for AD. More recently, large-scale genome-wide association studies are adding to the picture a number of common variants with very small effect sizes. Large-scale resequencing studies are expected to identify additional risk factors, including rare susceptibility variants and structural variation. Summary: Genetic assessment is currently of limited utility in clinical practice because of the low frequency (Mendelian mutations) or small effect size (common risk factors) of the currently known susceptibility genes. However, genetic studies are identifying with confidence a number of novel risk genes, and this will further our understanding of disease biology and possibly the identification of therapeutic targets. PMID:23558482

Practical Advice on Calculating Confidence Intervals for Radioprotection Effects and Reducing Animal Numbers in Radiation Countermeasure Experiments

PubMed Central

Landes, Reid D.; Lensing, Shelly Y.; Kodell, Ralph L.; Hauer-Jensen, Martin

2014-01-01

The dose of a substance that causes death in P% of a population is called an LDP, where LD stands for lethal dose. In radiation research, a common LDP of interest is the radiation dose that kills 50% of the population by a specified time, i.e., lethal dose 50 or LD50. When comparing LD50 between two populations, relative potency is the parameter of interest. In radiation research, this is commonly known as the dose reduction factor (DRF). Unfortunately, statistical inference on dose reduction factor is seldom reported. We illustrate how to calculate confidence intervals for dose reduction factor, which may then be used for statistical inference. Further, most dose reduction factor experiments use hundreds, rather than tens of animals. Through better dosing strategies and the use of a recently available sample size formula, we also show how animal numbers may be reduced while maintaining high statistical power. The illustrations center on realistic examples comparing LD50 values between a radiation countermeasure group and a radiation-only control. We also provide easy-to-use spreadsheets for sample size calculations and confidence interval calculations, as well as SAS® and R code for the latter. PMID:24164553

Pedigree and herd characterization of a donkey breed vulnerable to extinction.

PubMed

Quaresma, M; Martins, A M F; Rodrigues, J B; Colaço, J; Payan-Carreira, R

2014-03-01

Most donkey and local horse breeds are vulnerable to extinction as mechanization of agriculture progress throughout the world. The present study analyzed the pedigree and herd records of the donkey Asinina de Miranda breed (RAM), identifying genealogical and human factors that may affect the breed genetic diversity in the future and suggesting suitable strategies to breed preservation, early on the conservation program. The breeding rate was very low, with a ratio of foaling/live animals of 0.23 (178/760). The estimated number of founders and ancestors contributing to the reference population was 128 and 121. The number of founder herds in the reference population was 64, with an effective number of founder herds for the reference population of 7.6. The mean age of herd owners was 65.50 ± 0.884 years, with a negative association among the herd size and owner's age (P<0.001). In contrast, the size of the herd and the ownership of a male were both positively associated (P<0.001) with the herd number of in-born foals. Both the owners' age and the herd location (RAM home region v. dispersal region) were negatively associated with the foaling number (P<0.001). The main identified risk factors were: low breeding rates; low number of males and their unequal contribution to the genetic pool; unequal contribution of the herds to genetic pool; and advanced age of herd owners.

Optimization of scat detection methods for a social ungulate, the wild pig, and experimental evaluation of factors affecting detection of scat

USGS Publications Warehouse

Keiter, David A.; Cunningham, Fred L.; Rhodes, Olin E.; Irwin, Brian J.; Beasley, James

2016-01-01

Collection of scat samples is common in wildlife research, particularly for genetic capture-mark-recapture applications. Due to high degradation rates of genetic material in scat, large numbers of samples must be collected to generate robust estimates. Optimization of sampling approaches to account for taxa-specific patterns of scat deposition is, therefore, necessary to ensure sufficient sample collection. While scat collection methods have been widely studied in carnivores, research to maximize scat collection and noninvasive sampling efficiency for social ungulates is lacking. Further, environmental factors or scat morphology may influence detection of scat by observers. We contrasted performance of novel radial search protocols with existing adaptive cluster sampling protocols to quantify differences in observed amounts of wild pig (Sus scrofa) scat. We also evaluated the effects of environmental (percentage of vegetative ground cover and occurrence of rain immediately prior to sampling) and scat characteristics (fecal pellet size and number) on the detectability of scat by observers. We found that 15- and 20-m radial search protocols resulted in greater numbers of scats encountered than the previously used adaptive cluster sampling approach across habitat types, and that fecal pellet size, number of fecal pellets, percent vegetative ground cover, and recent rain events were significant predictors of scat detection. Our results suggest that use of a fixed-width radial search protocol may increase the number of scats detected for wild pigs, or other social ungulates, allowing more robust estimation of population metrics using noninvasive genetic sampling methods. Further, as fecal pellet size affected scat detection, juvenile or smaller-sized animals may be less detectable than adult or large animals, which could introduce bias into abundance estimates. Knowledge of relationships between environmental variables and scat detection may allow researchers to optimize sampling protocols to maximize utility of noninvasive sampling for wild pigs and other social ungulates.

Optimization of scat detection methods for a social ungulate, the wild pig, and experimental evaluation of factors affecting detection of scat

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

Keiter, David A.; Cunningham, Fred L.; Rhodes, Jr., Olin E.

Collection of scat samples is common in wildlife research, particularly for genetic capture-mark-recapture applications. Due to high degradation rates of genetic material in scat, large numbers of samples must be collected to generate robust estimates. Optimization of sampling approaches to account for taxa-specific patterns of scat deposition is, therefore, necessary to ensure sufficient sample collection. While scat collection methods have been widely studied in carnivores, research to maximize scat collection and noninvasive sampling efficiency for social ungulates is lacking. Further, environmental factors or scat morphology may influence detection of scat by observers. We contrasted performance of novel radial search protocolsmore » with existing adaptive cluster sampling protocols to quantify differences in observed amounts of wild pig ( Sus scrofa) scat. We also evaluated the effects of environmental (percentage of vegetative ground cover and occurrence of rain immediately prior to sampling) and scat characteristics (fecal pellet size and number) on the detectability of scat by observers. We found that 15- and 20-m radial search protocols resulted in greater numbers of scats encountered than the previously used adaptive cluster sampling approach across habitat types, and that fecal pellet size, number of fecal pellets, percent vegetative ground cover, and recent rain events were significant predictors of scat detection. Our results suggest that use of a fixed-width radial search protocol may increase the number of scats detected for wild pigs, or other social ungulates, allowing more robust estimation of population metrics using noninvasive genetic sampling methods. Further, as fecal pellet size affected scat detection, juvenile or smaller-sized animals may be less detectable than adult or large animals, which could introduce bias into abundance estimates. In conclusion, knowledge of relationships between environmental variables and scat detection may allow researchers to optimize sampling protocols to maximize utility of noninvasive sampling for wild pigs and other social ungulates.« less

Optimization of Scat Detection Methods for a Social Ungulate, the Wild Pig, and Experimental Evaluation of Factors Affecting Detection of Scat.

PubMed

Keiter, David A; Cunningham, Fred L; Rhodes, Olin E; Irwin, Brian J; Beasley, James C

2016-01-01

Collection of scat samples is common in wildlife research, particularly for genetic capture-mark-recapture applications. Due to high degradation rates of genetic material in scat, large numbers of samples must be collected to generate robust estimates. Optimization of sampling approaches to account for taxa-specific patterns of scat deposition is, therefore, necessary to ensure sufficient sample collection. While scat collection methods have been widely studied in carnivores, research to maximize scat collection and noninvasive sampling efficiency for social ungulates is lacking. Further, environmental factors or scat morphology may influence detection of scat by observers. We contrasted performance of novel radial search protocols with existing adaptive cluster sampling protocols to quantify differences in observed amounts of wild pig (Sus scrofa) scat. We also evaluated the effects of environmental (percentage of vegetative ground cover and occurrence of rain immediately prior to sampling) and scat characteristics (fecal pellet size and number) on the detectability of scat by observers. We found that 15- and 20-m radial search protocols resulted in greater numbers of scats encountered than the previously used adaptive cluster sampling approach across habitat types, and that fecal pellet size, number of fecal pellets, percent vegetative ground cover, and recent rain events were significant predictors of scat detection. Our results suggest that use of a fixed-width radial search protocol may increase the number of scats detected for wild pigs, or other social ungulates, allowing more robust estimation of population metrics using noninvasive genetic sampling methods. Further, as fecal pellet size affected scat detection, juvenile or smaller-sized animals may be less detectable than adult or large animals, which could introduce bias into abundance estimates. Knowledge of relationships between environmental variables and scat detection may allow researchers to optimize sampling protocols to maximize utility of noninvasive sampling for wild pigs and other social ungulates.

Optimization of scat detection methods for a social ungulate, the wild pig, and experimental evaluation of factors affecting detection of scat

DOE PAGES

Keiter, David A.; Cunningham, Fred L.; Rhodes, Jr., Olin E.; ...

2016-05-25

Collection of scat samples is common in wildlife research, particularly for genetic capture-mark-recapture applications. Due to high degradation rates of genetic material in scat, large numbers of samples must be collected to generate robust estimates. Optimization of sampling approaches to account for taxa-specific patterns of scat deposition is, therefore, necessary to ensure sufficient sample collection. While scat collection methods have been widely studied in carnivores, research to maximize scat collection and noninvasive sampling efficiency for social ungulates is lacking. Further, environmental factors or scat morphology may influence detection of scat by observers. We contrasted performance of novel radial search protocolsmore » with existing adaptive cluster sampling protocols to quantify differences in observed amounts of wild pig ( Sus scrofa) scat. We also evaluated the effects of environmental (percentage of vegetative ground cover and occurrence of rain immediately prior to sampling) and scat characteristics (fecal pellet size and number) on the detectability of scat by observers. We found that 15- and 20-m radial search protocols resulted in greater numbers of scats encountered than the previously used adaptive cluster sampling approach across habitat types, and that fecal pellet size, number of fecal pellets, percent vegetative ground cover, and recent rain events were significant predictors of scat detection. Our results suggest that use of a fixed-width radial search protocol may increase the number of scats detected for wild pigs, or other social ungulates, allowing more robust estimation of population metrics using noninvasive genetic sampling methods. Further, as fecal pellet size affected scat detection, juvenile or smaller-sized animals may be less detectable than adult or large animals, which could introduce bias into abundance estimates. In conclusion, knowledge of relationships between environmental variables and scat detection may allow researchers to optimize sampling protocols to maximize utility of noninvasive sampling for wild pigs and other social ungulates.« less

Stability and bias of classification rates in biological applications of discriminant analysis

USGS Publications Warehouse

Williams, B.K.; Titus, K.; Hines, J.E.

1990-01-01

We assessed the sampling stability of classification rates in discriminant analysis by using a factorial design with factors for multivariate dimensionality, dispersion structure, configuration of group means, and sample size. A total of 32,400 discriminant analyses were conducted, based on data from simulated populations with appropriate underlying statistical distributions. Simulation results indicated strong bias in correct classification rates when group sample sizes were small and when overlap among groups was high. We also found that stability of the correct classification rates was influenced by these factors, indicating that the number of samples required for a given level of precision increases with the amount of overlap among groups. In a review of 60 published studies, we found that 57% of the articles presented results on classification rates, though few of them mentioned potential biases in their results. Wildlife researchers should choose the total number of samples per group to be at least 2 times the number of variables to be measured when overlap among groups is low. Substantially more samples are required as the overlap among groups increases

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

Chitra Sivaraman, PNNL

Cloud droplet number concentration is an important factor in understanding aerosol-cloud interactions. As aerosol concentration increases, it is expected that droplet number concentration (Nd) will increase and droplet size will decrease, for a given liquid water path. This will greatly affect cloud albedo as smaller droplets reflect more shortwave radiation; however, the magnitude and variability of these processes under different environmental conditions is still uncertain.McComiskey et al. (2009) have implemented a method, based onBoers and Mitchell (1994), for calculating Nd from ground-based remote sensing measurements of optical depth and liquid water path. They show that the magnitude of the aerosol-cloudmore » interactions (ACI) varies with a range of factors, including the relative value of the cloud liquid water path (LWP), the aerosol size distribution, and the cloud updraft velocity. Estimates of Nd under a range of cloud types and conditions and at a variety of sites are needed to further quantify the impacts of aerosol cloud interactions. In order to provide data sets for studying aerosol-cloud interactions, the McComiskey et al. (2009) method was implemented as the Droplet Number Concentration (NDROP) value-added product (VAP).« less

Sample size and number of outcome measures of veterinary randomised controlled trials of pharmaceutical interventions funded by different sources, a cross-sectional study.

PubMed

Wareham, K J; Hyde, R M; Grindlay, D; Brennan, M L; Dean, R S

2017-10-04

Randomised controlled trials (RCTs) are a key component of the veterinary evidence base. Sample sizes and defined outcome measures are crucial components of RCTs. To describe the sample size and number of outcome measures of veterinary RCTs either funded by the pharmaceutical industry or not, published in 2011. A structured search of PubMed identified RCTs examining the efficacy of pharmaceutical interventions. Number of outcome measures, number of animals enrolled per trial, whether a primary outcome was identified, and the presence of a sample size calculation were extracted from the RCTs. The source of funding was identified for each trial and groups compared on the above parameters. Literature searches returned 972 papers; 86 papers comprising 126 individual trials were analysed. The median number of outcomes per trial was 5.0; there were no significant differences across funding groups (p = 0.133). The median number of animals enrolled per trial was 30.0; this was similar across funding groups (p = 0.302). A primary outcome was identified in 40.5% of trials and was significantly more likely to be stated in trials funded by a pharmaceutical company. A very low percentage of trials reported a sample size calculation (14.3%). Failure to report primary outcomes, justify sample sizes and the reporting of multiple outcome measures was a common feature in all of the clinical trials examined in this study. It is possible some of these factors may be affected by the source of funding of the studies, but the influence of funding needs to be explored with a larger number of trials. Some veterinary RCTs provide a weak evidence base and targeted strategies are required to improve the quality of veterinary RCTs to ensure there is reliable evidence on which to base clinical decisions.

The Optimum Font Size and Type for Students Aged 9-12 Reading Arabic Characters on Screen: A Case Study

NASA Astrophysics Data System (ADS)

Abubaker, A. A.; Lu, J.

2012-05-01

More and more, interest in the way data is displayed on screen has increased, especially with the increase in the number of people using e-text for learning purposes. So, this requires more focus on factors that affect screen legibility. Text display factors, such as font size, line length and font type, have an impact on reading online. Two font types [Arabic Traditional and Simplified Arabic] in four different sizes [10, 14, 16 and 18] are measured using Arabic text. On-line processes were measured using reading-aloud technique. Accuracy of reading was also measured by the average of errors that students made when reading the text, while reading speed was tested by the time it took students to read the text. However, results indicated that Arabic text in font size 10 is not readable to students aged 10 to 12. On the other hand, font sizes sixteen and eighteen are more readable than any smaller-sized font, the averages of error size 18 improve in all font types, while age has a significant impact on reading speed. Simplified Arabic font is reported as readable to students aged 10-12, especially in sizes 14 and 18.

Observed oil and gas field size distributions: A consequence of the discovery process and prices of oil and gas

USGS Publications Warehouse

Drew, L.J.; Attanasi, E.D.; Schuenemeyer, J.H.

1988-01-01

If observed oil and gas field size distributions are obtained by random samplings, the fitted distributions should approximate that of the parent population of oil and gas fields. However, empirical evidence strongly suggests that larger fields tend to be discovered earlier in the discovery process than they would be by random sampling. Economic factors also can limit the number of small fields that are developed and reported. This paper examines observed size distributions in state and federal waters of offshore Texas. Results of the analysis demonstrate how the shape of the observable size distributions change with significant hydrocarbon price changes. Comparison of state and federal observed size distributions in the offshore area shows how production cost differences also affect the shape of the observed size distribution. Methods for modifying the discovery rate estimation procedures when economic factors significantly affect the discovery sequence are presented. A primary conclusion of the analysis is that, because hydrocarbon price changes can significantly affect the observed discovery size distribution, one should not be confident about inferring the form and specific parameters of the parent field size distribution from the observed distributions. ?? 1988 International Association for Mathematical Geology.

Fifteen years of quantitative trait loci studies in fish: challenges and future directions.

PubMed

Ashton, David T; Ritchie, Peter A; Wellenreuther, Maren

2017-03-01

Understanding the genetic basis of phenotypic variation is a major challenge in biology. Here, we systematically evaluate 146 quantitative trait loci (QTL) studies on teleost fish over the last 15 years to investigate (i) temporal trends and (ii) factors affecting QTL detection and fine-mapping. The number of fish QTL studies per year increased over the review period and identified a cumulative number of 3632 putative QTLs. Most studies used linkage-based mapping approaches and were conducted on nonmodel species with limited genomic resources. A gradual and moderate increase in the size of the mapping population and a sharp increase in marker density from 2011 onwards were observed; however, the number of QTLs and variance explained by QTLs changed only minimally over the review period. Based on these findings, we discuss the causative factors and outline how larger sample sizes, phenomics, comparative genomics, epigenetics and software development could improve both the quantity and quality of QTLs in future genotype-phenotype studies. Given that the technical limitations on DNA sequencing have mostly been overcome in recent years, a renewed focus on these and other study design factors will likely lead to significant improvements in QTL studies in the future. © 2016 John Wiley & Sons Ltd.

Vocational students' learning preferences: the interpretability of ipsative data.

PubMed

Smith, P J

2000-02-01

A number of researchers have argued that ipsative data are not suitable for statistical procedures designed for normative data. Others have argued that the interpretability of such analyses of ipsative data are little affected where the number of variables and the sample size are sufficiently large. The research reported here represents a factor analysis of the scores on the Canfield Learning Styles Inventory for 1,252 students in vocational education. The results of the factor analysis of these ipsative data were examined in a context of existing theory and research on vocational students and lend support to the argument that the factor analysis of ipsative data can provide sensibly interpretable results.

Detailed characterization of particulate matter emitted by lean-burn gasoline direct injection engine

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

Zelenyuk, Alla; Wilson, Jacqueline; Imre, Dan

This study presents detailed characterization of the chemical and physical properties of PM emitted by a 2.0L BMW lean-burn turbocharged GDI engine operated under a number of combustion strategies that include lean homogeneous, lean stratified, stoichiometric, and fuel rich conditions. We characterized PM number concentrations, size distributions, and the size, mass, compositions, and effective density of fractal and compact individual exhaust particles. For the fractal particles, these measurements yielded fractal dimension, average diameter of primary spherules, and number of spherules, void fraction, and dynamic shape factors as function of particle size. Overall, the PM properties were shown to vary significantlymore » with engine operation condition. Lean stratified operation yielded the most diesel-like size distribution and the largest PM number and mass concentrations, with nearly all particles being fractal agglomerates composed of elemental carbon with small amounts of ash and organics. In contrast, stoichiometric operation yielded a larger fraction of ash particles, especially at low speed and low load. Three distinct forms of ash particles were observed, with their fractions strongly dependent on engine operating conditions: sub-50 nm ash particles, abundant at low speed and low load, ash-containing fractal particles, and large compact ash particles that significantly contribute to PM mass loadings« less

Quantum Simulation of Tunneling in Small Systems

PubMed Central

Sornborger, Andrew T.

2012-01-01

A number of quantum algorithms have been performed on small quantum computers; these include Shor's prime factorization algorithm, error correction, Grover's search algorithm and a number of analog and digital quantum simulations. Because of the number of gates and qubits necessary, however, digital quantum particle simulations remain untested. A contributing factor to the system size required is the number of ancillary qubits needed to implement matrix exponentials of the potential operator. Here, we show that a set of tunneling problems may be investigated with no ancillary qubits and a cost of one single-qubit operator per time step for the potential evolution, eliminating at least half of the quantum gates required for the algorithm and more than that in the general case. Such simulations are within reach of current quantum computer architectures. PMID:22916333

Properties and Fluxes of Primary Marine Aerosol Generated Via Detrainment of Turbulence-Modulated Bubble Plumes from Fresh North Atlantic Seawater

NASA Astrophysics Data System (ADS)

Keene, W. C.; Long, M. S.; Duplessis, P.; Kieber, D. J.; Maben, J. R.; Frossard, A. A.; Kinsey, J. D.; Beaupre, S. R.; Lu, X.; Chang, R.; Zhu, Y.; Bisgrove, J.

2017-12-01

During a September-October 2016 cruise of the R/V Endeavor in the western North Atlantic Ocean, primary marine aerosol (PMA) was produced in a high capacity generator during day and night via detrainment of bubbles from biologically productive and oligotrophic seawater. The turbulent mixing of clean air and seawater in a Venturi nozzle produced bubble plumes with tunable size distributions. Physicochemical characteristics of size-resolved PMA and seawater were measured. PMA number production efficiencies per unit air detrained (PEnum) increased with increasing detainment rate. For given conditions, PEnum values summed over size distributions were roughly ten times greater than those for frits whereas normalized size distributions were similar. Results show that bubble size distributions significantly modulated number production fluxes but not relative shapes of corresponding size distributions. In contrast, mass production efficiencies (PEmass) decreased with increasing air detrainment and were similar to those for frits, consistent with the hypothesis that bubble rafts on the seawater surface modulate emissions of larger jet droplets that dominate PMA mass production. Production efficiencies of organic matter were about three times greater than those for frits whereas organic enrichment factors integrated over size distributions were similar.

TP53 copy number expansion is associated with the evolution of increased body size and an enhanced DNA damage response in elephants

PubMed Central

Sulak, Michael; Fong, Lindsey; Mika, Katelyn; Chigurupati, Sravanthi; Yon, Lisa; Mongan, Nigel P; Emes, Richard D; Lynch, Vincent J

2016-01-01

A major constraint on the evolution of large body sizes in animals is an increased risk of developing cancer. There is no correlation, however, between body size and cancer risk. This lack of correlation is often referred to as 'Peto's Paradox'. Here, we show that the elephant genome encodes 20 copies of the tumor suppressor gene TP53 and that the increase in TP53 copy number occurred coincident with the evolution of large body sizes, the evolution of extreme sensitivity to genotoxic stress, and a hyperactive TP53 signaling pathway in the elephant (Proboscidean) lineage. Furthermore, we show that several of the TP53 retrogenes (TP53RTGs) are transcribed and likely translated. While TP53RTGs do not appear to directly function as transcription factors, they do contribute to the enhanced sensitivity of elephant cells to DNA damage and the induction of apoptosis by regulating activity of the TP53 signaling pathway. These results suggest that an increase in the copy number of TP53 may have played a direct role in the evolution of very large body sizes and the resolution of Peto's paradox in Proboscideans. DOI: http://dx.doi.org/10.7554/eLife.11994.001 PMID:27642012

Prognostic significance of anaplasia and angiogenesis in childhood medulloblastoma: a pediatric oncology group study.

PubMed

Ozer, Erdener; Sarialioglu, Faik; Cetingoz, Riza; Yüceer, Nurullah; Cakmakci, Handan; Ozkal, Sermin; Olgun, Nur; Uysal, Kamer; Corapcioglu, Funda; Canda, Serefettin

2004-01-01

The purpose of this study was to investigate whether quantitative assessment of cytologic anaplasia and angiogenesis may predict the clinical prognosis in medulloblastoma and stratify the patients to avoid both undertreatment and overtreatment. Medulloblastomas from 23 patients belonging to the Pediatric Oncology Group were evaluated with respect to some prognostic variables, including histologic assessment of nodularity and desmoplasia, grading of anaplasia, measurement of nuclear size, mitotic cell count, quantification of angiogenesis, including vascular surface density (VSD) and microvessel number (NVES), and immunohistochemical scoring of vascular endothelial growth factor (VEGF) expression. Univariate and multivariate analyses for prognostic indicators for survival were performed. Univariate analysis revealed that extensive nodularity was a significant favorable prognostic factor, whereas the presence of anaplasia, increased nuclear size, mitotic rate, VSD, and NVES were significant unfavorable prognostic factors. Using multivariate analysis, increased nuclear size was found to be an independent unfavorable prognostic factor for survival. Neither the presence of desmoplasia nor VEGF expression was significantly related to patient survival. Although care must be taken not to overstate the importance of the results of this single-institution preliminary report, pathologic grading of medulloblastomas with respect to grading of anaplasia and quantification of nodularity, nuclear size, and microvessel profiles may be clinically useful for the treatment of medulloblastomas. Further validation of the independent prognostic significance of nuclear size in stratifying patients is required.

Dilution effects on ultrafine particle emissions from Euro 5 and Euro 6 diesel and gasoline vehicles

NASA Astrophysics Data System (ADS)

Louis, Cédric; Liu, Yao; Martinet, Simon; D'Anna, Barbara; Valiente, Alvaro Martinez; Boreave, Antoinette; R'Mili, Badr; Tassel, Patrick; Perret, Pascal; André, Michel

2017-11-01

Dilution and temperature used during sampling of vehicle exhaust can modify particle number concentration and size distribution. Two experiments were performed on a chassis dynamometer to assess exhaust dilution and temperature on particle number and particle size distribution for Euro 5 and Euro 6 vehicles. In the first experiment, the effects of dilution (ratio from 8 to 4 000) and temperature (ranging from 50 °C to 150 °C) on particle quantification were investigated directly from tailpipe for a diesel and a gasoline Euro 5 vehicles. In the second experiment, particle emissions from Euro 6 diesel and gasoline vehicles directly sampled from the tailpipe were compared to the constant volume sampling (CVS) measurements under similar sampling conditions. Low primary dilutions (3-5) induced an increase in particle number concentration by a factor of 2 compared to high primary dilutions (12-20). Low dilution temperatures (50 °C) induced 1.4-3 times higher particle number concentration than high dilution temperatures (150 °C). For the Euro 6 gasoline vehicle with direct injection, constant volume sampling (CVS) particle number concentrations were higher than after the tailpipe by a factor of 6, 80 and 22 for Artemis urban, road and motorway, respectively. For the same vehicle, particle size distribution measured after the tailpipe was centred on 10 nm, and particles were smaller than the ones measured after CVS that was centred between 50 nm and 70 nm. The high particle concentration (≈106 #/cm3) and the growth of diameter, measured in the CVS, highlighted aerosol transformations, such as nucleation, condensation and coagulation occurring in the sampling system and this might have biased the particle measurements.

Factors That Modulate Properties of Primary Marine Aerosol Generated From Ambient Seawater on Ships at Sea

NASA Astrophysics Data System (ADS)

Keene, William C.; Long, Michael S.; Reid, Jeffrey S.; Frossard, Amanda A.; Kieber, David J.; Maben, John R.; Russell, Lynn M.; Kinsey, Joanna D.; Quinn, Patricia K.; Bates, Timothy S.

2017-11-01

Model primary marine aerosol (mPMA) was produced by bubbling clean air through flowing natural seawater in a high-capacity generator deployed on ships in the eastern North Pacific and western North Atlantic Oceans. Physicochemical properties of seawater and mPMA were quantified to characterize factors that modulated production. Differences in surfactant organic matter (OM) and associated properties including surface tension sustained plumes with smaller bubble sizes, slower rise velocities, larger void fractions, and older surface ages in biologically productive relative to oligotrophic seawater. Production efficiencies for mPMA number (PEnum) and mass (PEmass) per unit air detrained from biologically productive seawater during daytime were greater and mass median diameters smaller than those in the same seawater at night and in oligotrophic seawater during day and night. PEmass decreased with increasing air detrainment rate suggesting that surface bubble rafts suppressed emission of jet droplets and associated mPMA mass. Relative to bubbles emitted at 60 cm depth, PEnum for bubbles emitted from 100 cm depth was approximately 2 times greater. mPMA OM enrichment factors (EFs) and mass fractions based on a coarse frit, fine frits, and a seawater jet exhibited similar size-dependent variability over a wide range in chlorophyll a concentrations. Results indicate that the physical production of PMA number and mass from the ocean surface varies systematically as interrelated functions of seawater type and, in biologically productive waters, time of day; bubble injection rate, depth, size, and surface age; and physical characteristics of the air-water interface whereas size-resolved OM EFs and mass fractions are relatively invariant.

Factors controlling particle number concentration and size at metro stations

NASA Astrophysics Data System (ADS)

Reche, C.; Moreno, T.; Martins, V.; Minguillón, M. C.; Jones, T.; de Miguel, E.; Capdevila, M.; Centelles, S.; Querol, X.

2017-05-01

An extensive air quality campaign was performed at differently designed station platforms in the Barcelona metro system, aiming to investigate the factors governing airborne particle number (N) concentrations and their size distributions. The study of the daily trends of N concentrations by different size ranges shows that concentrations of N0.3-10 are closely related with the schedule of the metro service. Conversely, the hourly variation of N0.007-10 (mainly composed of ultrafine particles) could be partly governed by the entrance of particles from outdoor emissions through mechanical ventilation. Measurements under different ventilation settings at three metro platforms reveal that the effect on air quality linked to changes in the tunnel ventilation depends on the station design. Night-time maintenance works in tunnels are frequent activities in the metro system; and after intense prolonged works, these can result in higher N concentrations at platforms during the following metro operating hours (by up to 30%), this being especially evident for N1-10. Due to the complex mixture of factors controlling N, together with the differences in trends recorded for particles within different size ranges, developing an air quality strategy at metro systems is a great challenge. When compared to street-level urban particles concentrations, the priority in metro air quality should be dealing with particles coarser than 0.3 μm. In fact, the results suggest that at narrow platforms served by single-track tunnels the current forced tunnel ventilation during operating hours is less efficient in reducing coarse particles compared to fine.

Regulation of aggregate size and pattern by adenosine and caffeine in cellular slime molds

PubMed Central

2012-01-01

Background Multicellularity in cellular slime molds is achieved by aggregation of several hundreds to thousands of cells. In the model slime mold Dictyostelium discoideum, adenosine is known to increase the aggregate size and its antagonist caffeine reduces the aggregate size. However, it is not clear if the actions of adenosine and caffeine are evolutionarily conserved among other slime molds known to use structurally unrelated chemoattractants. We have examined how the known factors affecting aggregate size are modulated by adenosine and caffeine. Result Adenosine and caffeine induced the formation of large and small aggregates respectively, in evolutionarily distinct slime molds known to use diverse chemoattractants for their aggregation. Due to its genetic tractability, we chose D. discoideum to further investigate the factors affecting aggregate size. The changes in aggregate size are caused by the effect of the compounds on several parameters such as cell number and size, cell-cell adhesion, cAMP signal relay and cell counting mechanisms. While some of the effects of these two compounds are opposite to each other, interestingly, both compounds increase the intracellular glucose level and strengthen cell-cell adhesion. These compounds also inhibit the synthesis of cAMP phosphodiesterase (PdsA), weakening the relay of extracellular cAMP signal. Adenosine as well as caffeine rescue mutants impaired in stream formation (pde4- and pdiA-) and colony size (smlA- and ctnA-) and restore their parental aggregate size. Conclusion Adenosine increased the cell division timings thereby making large number of cells available for aggregation and also it marginally increased the cell size contributing to large aggregate size. Reduced cell division rates and decreased cell size in the presence of caffeine makes the aggregates smaller than controls. Both the compounds altered the speed of the chemotactic amoebae causing a variation in aggregate size. Our data strongly suggests that cytosolic glucose and extracellular cAMP levels are the other major determinants regulating aggregate size and pattern. Importantly, the aggregation process is conserved among different lineages of cellular slime molds despite using unrelated signalling molecules for aggregation. PMID:22269093

Regulation of aggregate size and pattern by adenosine and caffeine in cellular slime molds.

PubMed

Jaiswal, Pundrik; Soldati, Thierry; Thewes, Sascha; Baskar, Ramamurthy

2012-01-23

Multicellularity in cellular slime molds is achieved by aggregation of several hundreds to thousands of cells. In the model slime mold Dictyostelium discoideum, adenosine is known to increase the aggregate size and its antagonist caffeine reduces the aggregate size. However, it is not clear if the actions of adenosine and caffeine are evolutionarily conserved among other slime molds known to use structurally unrelated chemoattractants. We have examined how the known factors affecting aggregate size are modulated by adenosine and caffeine. Adenosine and caffeine induced the formation of large and small aggregates respectively, in evolutionarily distinct slime molds known to use diverse chemoattractants for their aggregation. Due to its genetic tractability, we chose D. discoideum to further investigate the factors affecting aggregate size. The changes in aggregate size are caused by the effect of the compounds on several parameters such as cell number and size, cell-cell adhesion, cAMP signal relay and cell counting mechanisms. While some of the effects of these two compounds are opposite to each other, interestingly, both compounds increase the intracellular glucose level and strengthen cell-cell adhesion. These compounds also inhibit the synthesis of cAMP phosphodiesterase (PdsA), weakening the relay of extracellular cAMP signal. Adenosine as well as caffeine rescue mutants impaired in stream formation (pde4- and pdiA-) and colony size (smlA- and ctnA-) and restore their parental aggregate size. Adenosine increased the cell division timings thereby making large number of cells available for aggregation and also it marginally increased the cell size contributing to large aggregate size. Reduced cell division rates and decreased cell size in the presence of caffeine makes the aggregates smaller than controls. Both the compounds altered the speed of the chemotactic amoebae causing a variation in aggregate size. Our data strongly suggests that cytosolic glucose and extracellular cAMP levels are the other major determinants regulating aggregate size and pattern. Importantly, the aggregation process is conserved among different lineages of cellular slime molds despite using unrelated signalling molecules for aggregation.

Comparison of two estimation methods for surface area concentration using number concentration and mass concentration of combustion-related ultrafine particles

NASA Astrophysics Data System (ADS)

Park, Ji Young; Raynor, Peter C.; Maynard, Andrew D.; Eberly, Lynn E.; Ramachandran, Gurumurthy

Recent research has suggested that the adverse health effects caused by nanoparticles are associated with their surface area (SA) concentrations. In this study, SA was estimated in two ways using number and mass concentrations and compared with SA (SA meas) measured using a diffusion charger (DC). Aerosol measurements were made twice: once starting in October 2002 and again starting in December 2002 in Mysore, India in residences that used kerosene or liquefied petroleum gas (LPG) for cooking. Mass, number, and SA concentrations and size distributions by number were measured in each residence. The first estimation method (SA PSD) used the size distribution by number to estimate SA. The second method (SA INV) used a simple inversion scheme that incorporated number and mass concentrations while assuming a lognormal size distribution with a known geometrical standard deviation. SA PSD was, on average, 2.4 times greater (range = 1.6-3.4) than SA meas while SA INV was, on average, 6.0 times greater (range = 4.6-7.7) than SA meas. The logarithms of SA PSD and SA INV were found to be statistically significant predictors of the logarithm of SA meas. The study showed that particle number and mass concentration measurements can be used to estimate SA with a correction factor that ranges between 2 and 6.

[Clinical examination of children with tooth aplasia. Correlations between dental symptoms and the whole organism].

PubMed

Knolmayer, Judit; Bognár, Veronika; Szabó, Gyula

2008-10-01

The characteristic abnormalities of jaws, teeth, and salivation can be measured and expressed by numbers. The possible etiological factors, like the positive family history of noxas during the pregnancy can be explored. In our study we examined the symptoms of general organic system and teeth trait--jaw relation, seriousness of aplasia, abnormalities of teeth in size--defect of salivary glands and the presence of possible etiological factors. Thirty children were examined. The symptoms of general organic system were diagnosed. 60% of tooth agenesis occurs in the maxilla, the size of teeth reduced also in the upper jaw. Pseudoprogenia can be explained by these facts. The size reduction of extant teeth appeared stronger in the labiolingual direction. The salivary secretion rate in examined children proved significantly lower than in the control group. Seven siblings and eight parents were identified by examining the etiological factors. We did not find any noxas during the pregnancy by our questionnaire method.

Energy Consumption of Die Casting Operations

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

Jerald Brevick; clark Mount-Campbell; Carroll Mobley

2004-03-15

Molten metal processing is inherently energy intensive and roughly 25% of the cost of die-cast products can be traced to some form of energy consumption [1]. The obvious major energy requirements are for melting and holding molten alloy in preparation for casting. The proper selection and maintenance of melting and holding equipment are clearly important factors in minimizing energy consumption in die-casting operations [2]. In addition to energy consumption, furnace selection also influences metal loss due to oxidation, metal quality, and maintenance requirements. Other important factors influencing energy consumption in a die-casting facility include geographic location, alloy(s) cast, starting formmore » of alloy (solid or liquid), overall process flow, casting yield, scrap rate, cycle times, number of shifts per day, days of operation per month, type and size of die-casting form of alloy (solid or liquid), overall process flow, casting yield, scrap rate, cycle times, number of shifts per day, days of operation per month, type and size of die-casting machine, related equipment (robots, trim presses), and downstream processing (machining, plating, assembly, etc.). Each of these factors also may influence the casting quality and productivity of a die-casting enterprise. In a die-casting enterprise, decisions regarding these issues are made frequently and are based on a large number of factors. Therefore, it is not surprising that energy consumption can vary significantly from one die-casting enterprise to the next, and within a single enterprise as function of time.« less

Publications by doctoral candidates at Charité University Hospital, Berlin, from 1998-2008.

PubMed

Ziemann, Esther; Oestmann, Jörg-Wilhelm

2012-05-01

One quality parameter of medical theses is the number of articles published by the doctoral candidates. Over the course of the past decade the Charité-Universitätsmedizin Berlin has taken steps to improve the quality of the theses completed by its doctoral students in medicine and increase their publication activity. This study was designed to verify the efficacy of these measures and to detect general trends. Medical theses completed in 1998, 2004 and 2008 (sample size >250 for each year) were retrospectively analyzed with regard to associated publications within a 7-year period (from 5 years before completion to 2 years thereafter). Quality and quantity were recorded. Publications found in the PubMed database were evaluated; the impact factor of the publishing journal was used as quality parameter. The sample sizes were 264 for 1998, 316 for 2004, and 316 for 2008. The number of publications per doctoral student increased from 0.78 to 1.39 over the course of the study period, and the average impact factor rose from 2.42 to 3.62. Analysis using the current impact factors of the publishing journals showed an increase from 3.13 to 3.85. The proportion of case reports fell from 12.7% to 8%. The proportion of first authorships remained about the same. The past decade has seen an increase in the number of publications by doctoral students at the Charité and a rise in the average impact factor of the journals concerned.

Ball mill tool for crushing coffee and cocoa beans base on fraction size sieving results

NASA Astrophysics Data System (ADS)

Haryanto, B.; Sirait, M.; Azalea, M.; Alvin; Cahyani, S. E.

2018-02-01

Crushing is one of the operation units that aimed to convert the size of solid material to be smoother particle’s size. The operation unit that can be used in this crushing is ball mill. The purpose of this study is to foresee the effect of raw material mass, grinding time, and the number of balls that are used in the ball mill tool related to the amount of raw material of coffee and cocoa beans. Solid material that has become smooth is then sieved with sieve mesh with size number: 50, 70, 100, and 140. It is in order to obtain the mass fraction that escaped from each sieve mesh. From the experiment, it can be concluded that mass percentage fraction of coffee powder is bigger than cocoa powder that escaped from the mesh. Hardness and humidity of coffee beans and cocoa beans have been the important factors that made coffee beans is easier to be crushed than cocoa beans.

SHOEBOX Modulates Root Meristem Size in Rice through Dose-Dependent Effects of Gibberellins on Cell Elongation and Proliferation

PubMed Central

Li, Jintao; Zhao, Yu; Chu, Huangwei; Wang, Likai; Fu, Yanru; Liu, Ping; Upadhyaya, Narayana; Chen, Chunli; Mou, Tongmin; Feng, Yuqi; Kumar, Prakash; Xu, Jian

2015-01-01

Little is known about how the size of meristem cells is regulated and whether it participates in the control of meristem size in plants. Here, we report our findings on shoebox (shb), a mild gibberellin (GA) deficient rice mutant that has a short root meristem size. Quantitative analysis of cortical cell length and number indicates that shb has shorter, rather than fewer, cells in the root meristem until around the fifth day after sowing, from which the number of cortical cells is also reduced. These defects can be either corrected by exogenous application of bioactive GA or induced in wild-type roots by a dose-dependent inhibitory effect of paclobutrazol on GA biosynthesis, suggesting that GA deficiency is the primary cause of shb mutant phenotypes. SHB encodes an AP2/ERF transcription factor that directly activates transcription of the GA biosynthesis gene KS1. Thus, root meristem size in rice is modulated by SHB-mediated GA biosynthesis that regulates the elongation and proliferation of meristem cells in a developmental stage-specific manner. PMID:26275148

SHOEBOX Modulates Root Meristem Size in Rice through Dose-Dependent Effects of Gibberellins on Cell Elongation and Proliferation.

PubMed

Li, Jintao; Zhao, Yu; Chu, Huangwei; Wang, Likai; Fu, Yanru; Liu, Ping; Upadhyaya, Narayana; Chen, Chunli; Mou, Tongmin; Feng, Yuqi; Kumar, Prakash; Xu, Jian

2015-08-01

Little is known about how the size of meristem cells is regulated and whether it participates in the control of meristem size in plants. Here, we report our findings on shoebox (shb), a mild gibberellin (GA) deficient rice mutant that has a short root meristem size. Quantitative analysis of cortical cell length and number indicates that shb has shorter, rather than fewer, cells in the root meristem until around the fifth day after sowing, from which the number of cortical cells is also reduced. These defects can be either corrected by exogenous application of bioactive GA or induced in wild-type roots by a dose-dependent inhibitory effect of paclobutrazol on GA biosynthesis, suggesting that GA deficiency is the primary cause of shb mutant phenotypes. SHB encodes an AP2/ERF transcription factor that directly activates transcription of the GA biosynthesis gene KS1. Thus, root meristem size in rice is modulated by SHB-mediated GA biosynthesis that regulates the elongation and proliferation of meristem cells in a developmental stage-specific manner.

Factors Influencing Ferrihydrite Crystallinity In Natural And Synthetic Systems

EPA Science Inventory

Recent investigations of the structure of the mineral ferrihydrite indicate that disparities in the number of peaks observed in powder x-ray diffraction patterns can be attributed to differences in crystallite size. This has lead to the conclusion that specimens previously refer...

The quality of the reported sample size calculations in randomized controlled trials indexed in PubMed.

PubMed

Lee, Paul H; Tse, Andy C Y

2017-05-01

There are limited data on the quality of reporting of information essential for replication of the calculation as well as the accuracy of the sample size calculation. We examine the current quality of reporting of the sample size calculation in randomized controlled trials (RCTs) published in PubMed and to examine the variation in reporting across study design, study characteristics, and journal impact factor. We also reviewed the targeted sample size reported in trial registries. We reviewed and analyzed all RCTs published in December 2014 with journals indexed in PubMed. The 2014 Impact Factors for the journals were used as proxies for their quality. Of the 451 analyzed papers, 58.1% reported an a priori sample size calculation. Nearly all papers provided the level of significance (97.7%) and desired power (96.6%), and most of the papers reported the minimum clinically important effect size (73.3%). The median (inter-quartile range) of the percentage difference of the reported and calculated sample size calculation was 0.0% (IQR -4.6%;3.0%). The accuracy of the reported sample size was better for studies published in journals that endorsed the CONSORT statement and journals with an impact factor. A total of 98 papers had provided targeted sample size on trial registries and about two-third of these papers (n=62) reported sample size calculation, but only 25 (40.3%) had no discrepancy with the reported number in the trial registries. The reporting of the sample size calculation in RCTs published in PubMed-indexed journals and trial registries were poor. The CONSORT statement should be more widely endorsed. Copyright © 2016 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Repeated Habitat Disturbances by Fire Decrease Local Effective Population Size.

PubMed

Schrey, Aaron W; Ragsdale, Alexandria K; McCoy, Earl D; Mushinsky, Henry R

2016-07-01

Effective population size is a fundamental parameter in population genetics, and factors that alter effective population size will shape the genetic characteristics of populations. Habitat disturbance may have a large effect on genetic characteristics of populations by influencing immigration and gene flow, particularly in fragmented habitats. We used the Florida Sand Skink (Plestiodon reynoldsi) to investigate the effect of fire-based habitat disturbances on the effective population size in the highly threatened, severely fragmented, and fire dependent Florida scrub habitat. We screened 7 microsatellite loci in 604 individuals collected from 12 locations at Archbold Biological Station. Archbold Biological Station has an active fire management plan and detailed records of fires dating to 1967. Our objective was to determine how the timing, number, and intervals between fires affect effective population size, focusing on multiple fires in the same location. Effective population size was higher in areas that had not been burned for more than 10 years and decreased with number of fires and shorter time between fires. A similar pattern was observed in abundance: increasing abundance with time-since-fire and decreasing abundance with number of fires. The ratio of effective population size to census size was higher at sites with more recent fires and tended to decrease with time-since-last-fire. These results suggest that habitat disturbances, such as fire, may have a large effect in the genetic characteristics of local populations and that Florida Sand Skinks are well adapted to the natural fire dynamics required to maintain Florida scrub. © The American Genetic Association. 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Small numbers, disclosure risk, security, and reliability issues in Web-based data query systems.

PubMed

Rudolph, Barbara A; Shah, Gulzar H; Love, Denise

2006-01-01

This article describes the process for developing consensus guidelines and tools for releasing public health data via the Web and highlights approaches leading agencies have taken to balance disclosure risk with public dissemination of reliable health statistics. An agency's choice of statistical methods for improving the reliability of released data for Web-based query systems is based upon a number of factors, including query system design (dynamic analysis vs preaggregated data and tables), population size, cell size, data use, and how data will be supplied to users. The article also describes those efforts that are necessary to reduce the risk of disclosure of an individual's protected health information.

Characteristics of quantitative perfusion parameters on dynamic contrast‐enhanced MRI in mammographically occult breast cancer

PubMed Central

Ryu, Jung Kyu; Rhee, Sun Jung; Song, Jeong Yoon; Cho, Soo Hyun

2016-01-01

The purpose of this study was to compare the characteristics of quantitative perfusion parameters obtained from dynamic contrast‐enhanced (DCE) magnetic resonance imaging (MRI) in patients with mammographically occult (MO) breast cancers and those with mammographically visible (MV) breast cancers. Quantitative parameters (AUC, Ktrans,kep,ve,vp, and wi) from 13 MO breast cancers and 16 MV breast cancers were mapped after the DCE‐MRI data were acquired. Various prognostic factors, including axillary nodal status, estrogen receptor (ER), progesterone receptor (PR), Ki‐67, p53, E‐cadherin, and human epidermal growth factor receptor 2 (HER2) were obtained in each group. Fisher's exact test was used to compare any differences of the various prognostic factors between the two groups. The Mann‐Whitney U test was applied to compare the quantitative parameters between these two groups. Finally, Spearman's correlation was used to investigate the relationships between perfusion indices and four factors — age, tumor size, Ki‐67, and p53 — for each group. Although age, tumor size, and the prognostic factors were not statistically different between the two groups, the mean values of the quantitative parameters, except wi in the MV group, were higher than those in the MO group without statistical significance (p=0.219). The kep value was significantly different between the two groups (p=0.048), but the other parameters were not. In the MO group, vp with size, ve with p53, and Ktrans and vp with Ki‐67 had significant correlations (p<0.05). However, in the MV group, only kep showed significant correlation with age. The kep value was only the perfusion parameter of statistical significance between MO and MV breast cancers. PACS number(s): 87.19.U‐, 87.61.‐c PMID:27685105

Factors that affect the fatigue strength of power transmission shafting

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.

1984-01-01

A long standing objective in the design of power transmission shafting is to eliminate excess shaft material without compromising operational reliability. A shaft design method is presented which accounts for variable amplitude loading histories and their influence on limited life designs. The effects of combined bending and torsional loading are considered along with a number of application factors known to influence the fatigue strength of shafting materials. Among the factors examined are surface condition, size, stress concentration, residual stress and corrosion fatigue.

Sensory factors limiting horizontal and vertical visual span for letter recognition

PubMed Central

Yu, Deyue; Legge, Gordon E.; Wagoner, Gunther; Chung, Susana T. L.

2014-01-01

Reading speed for English text is slower for text oriented vertically than horizontally. Yu, Park, Gerold, and Legge (2010) showed that slower reading of vertical text is associated with a smaller visual span (the number of letters recognized with high accuracy without moving the eyes). Three possible sensory determinants of the size of the visual span are: resolution (decreasing acuity at letter positions farther from the midline), mislocations (uncertainty about the relative position of letters in strings), and crowding (interference from flanking letters in recognizing the target letter). In the present study, we asked which of these factors is most important in determining the size of the visual span, and likely in turn in determining the horizontal/vertical difference in reading when letter size is above the critical print size for reading. We used a decomposition analysis to represent constraints due to resolution, mislocations, and crowding as losses in information transmitted (in bits) about letter recognition. Across vertical and horizontal conditions, crowding accounted for 75% of the loss in information, mislocations accounted for 19% of the loss, and declining acuity away from fixation accounted for only 6%. We conclude that crowding is the major factor limiting the size of the visual span, and that the horizontal/vertical difference in the size of the visual span is associated with stronger crowding along the vertical midline. PMID:25187253

Sensory factors limiting horizontal and vertical visual span for letter recognition

PubMed Central

Yu, Deyue; Legge, Gordon E.; Wagoner, Gunther; Chung, Susana T. L.

2014-01-01

Reading speed for English text is slower for text oriented vertically than horizontally. Yu, Park, Gerold, and Legge (2010) showed that slower reading of vertical text is associated with a smaller visual span (the number of letters recognized with high accuracy without moving the eyes). Three possible sensory determinants of the size of the visual span are: resolution (decreasing acuity at letter positions farther from the midline), mislocations (uncertainty about the relative position of letters in strings), and crowding (interference from flanking letters in recognizing the target letter). In the present study, we asked which of these factors is most important in determining the size of the visual span, and likely in turn in determining the horizontal/vertical difference in reading when letter size is above the critical print size for reading. We used a decomposition analysis to represent constraints due to resolution, mislocations, and crowding as losses in information transmitted (in bits) about letter recognition. Across vertical and horizontal conditions, crowding accounted for 75% of the loss in information, mislocations accounted for 19% of the loss, and declining acuity away from fixation accounted for only 6%. We conclude that crowding is the major factor limiting the size of the visual span, and that the horizontal/vertical difference in the size of the visual span is associated with stronger crowding along the vertical midline.

Publication Productivity in Central Asia and Countries of the Former Soviet Union.

PubMed

Adambekov, Shalkar; Askarova, Sholpan; Welburn, Sharon C; Goughnour, Sharon L; Konishi, Ayumi; LaPorte, Ronald; Linkov, Faina

2016-01-01

Despite the significant number of research institutions and rich scientific heritage, published research from Central Asia (Kazakhstan, Uzbekistan, Kyrgyzstan, Tajikistan, and Turkmenistan) is traditionally underrepresented in international scientific literature. The goal of this paper was to analyze publication patterns in Central Asian countries, and to explore the factors that contributed to the publication productivity in Kazakhstan. Publication productivity was evaluated using data generated by the SCImago Journal & Country Rank over the period of 1996-2014 for all of the 15 former Soviet Union Republics for all subject categories. Country specific data, including total population, gross domestic product (GDP) per capita, research and development (R&D) expenditure (% of GDP), number of reserchers (per million people), was abstracted from World Bank data. ANOVA and ANCOVA analyses compared the mean number of publications among Central Asian countries. Separate analyses was done for publication patterns in the health sciences. Multiple comparisons were performed using Tukey method. The analysis of publication productivity showed significant discrepancies in the number of published documents among the Central Asian countries. Kazakhstan demonstrated a significant increase in the number of published documents in the period of 1996-2014, mainly in the areas of natural and multidisciplinary sciences. Our analyses also showed that the number of publications are siginicantly associated with GDP and population size. We identified large gaps in publication productivity among the Central Asian countries. The association between publication rate with GDP and population size indicates there is a need to adjust for these factors when planning research policy.

A Study of the Relationship Between Anthropogenic Sulfate and Cloud Drop Nucleation

NASA Technical Reports Server (NTRS)

Chuang, Catherine C.; Penner, Joyce E.

1994-01-01

The characteristics of the cloud drop size distribution near cloud base are initially determined by the aerosol particles that serve as CCN and by the local updraft velocity. Chemical reactions of the emitted gaseous sulfur compounds due to human activities will alter, through gas-to-particle conversion, the aerosol size distribution, total number, and its chemical composition. Recently, Boucher and Rodhe and Jones et.al have each developed parameterizations relating cloud drop concentration to sulfate mass or aerosol number concentration, respectively, and used them to develop estimates of the indirect forcing by anthropogenic sulfate aerosols. THese parameterizations made use of measure relationships in continental and maritime clouds. However, these relationships are inherently noisy, yielding more than a factor of 2 variation in cloud drop concentration for a given aerosol number (or for a given sulfate mass) concentration. The large spatial and temporal variabilities in the concentration, chemical characteristics, and size distribution of aerosols have made it difficult to develop such a parameterization from data. In this paper, our focus is to develop a means for relating the predicted anthropogenic sulfate mass to cloud drop number concentration over the range of expected conditions associated with continental and marine aerosol. We start with an assumed pre-existing particle size distribution and develop an approximation of the altered distribution after addition of anthropogenic sulfate. We thereby develop a conservative estimate of the possible change in cloud drop number concentration due to anthropogenic sulfate.

A Meta-Analysis of Factors Influencing the Development of Trust in Automation: Implications for Understanding Autonomy in Future Systems.

PubMed

Schaefer, Kristin E; Chen, Jessie Y C; Szalma, James L; Hancock, P A

2016-05-01

We used meta-analysis to assess research concerning human trust in automation to understand the foundation upon which future autonomous systems can be built. Trust is increasingly important in the growing need for synergistic human-machine teaming. Thus, we expand on our previous meta-analytic foundation in the field of human-robot interaction to include all of automation interaction. We used meta-analysis to assess trust in automation. Thirty studies provided 164 pairwise effect sizes, and 16 studies provided 63 correlational effect sizes. The overall effect size of all factors on trust development was ḡ = +0.48, and the correlational effect was [Formula: see text]  = +0.34, each of which represented medium effects. Moderator effects were observed for the human-related (ḡ  = +0.49; [Formula: see text] = +0.16) and automation-related (ḡ = +0.53; [Formula: see text] = +0.41) factors. Moderator effects specific to environmental factors proved insufficient in number to calculate at this time. Findings provide a quantitative representation of factors influencing the development of trust in automation as well as identify additional areas of needed empirical research. This work has important implications to the enhancement of current and future human-automation interaction, especially in high-risk or extreme performance environments. © 2016, Human Factors and Ergonomics Society.

46 CFR 160.035-10 - Number of persons allowed in lifeboats.

Code of Federal Regulations, 2010 CFR

2010-10-01

... cubic feet by the factor shown in Table 160.035-10(a). The net cubic capacity shall be determined by § 160.035-9(b). Table 160.035-10(a) Length in feet— Of— But less than— Factor 18 14 18 20 13 20 22 12 22... for which seating space is provided as determined by drawing figures to scale of a size as noted in...

A review of visual cues associated with food on food acceptance and consumption.

PubMed

Wadhera, Devina; Capaldi-Phillips, Elizabeth D

2014-01-01

Several sensory cues affect food intake including appearance, taste, odor, texture, temperature, and flavor. Although taste is an important factor regulating food intake, in most cases, the first sensory contact with food is through the eyes. Few studies have examined the effects of the appearance of a food portion on food acceptance and consumption. The purpose of this review is to identify the various visual factors associated with food such as proximity, visibility, color, variety, portion size, height, shape, number, volume, and the surface area and their effects on food acceptance and consumption. We suggest some ways that visual cues can be used to increase fruit and vegetable intake in children and decrease excessive food intake in adults. In addition, we discuss the need for future studies that can further establish the relationship between several unexplored visual dimensions of food (specifically shape, number, size, and surface area) and food intake. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

The Driving Forces of Cultural Complexity : Neanderthals, Modern Humans, and the Question of Population Size.

PubMed

Fogarty, Laurel; Wakano, Joe Yuichiro; Feldman, Marcus W; Aoki, Kenichi

2017-03-01

The forces driving cultural accumulation in human populations, both modern and ancient, are hotly debated. Did genetic, demographic, or cognitive features of behaviorally modern humans (as opposed to, say, early modern humans or Neanderthals) allow culture to accumulate to its current, unprecedented levels of complexity? Theoretical explanations for patterns of accumulation often invoke demographic factors such as population size or density, whereas statistical analyses of variation in cultural complexity often point to the importance of environmental factors such as food stability, in determining cultural complexity. Here we use both an analytical model and an agent-based simulation model to show that a full understanding of the emergence of behavioral modernity, and the cultural evolution that has followed, depends on understanding and untangling the complex relationships among culture, genetically determined cognitive ability, and demographic history. For example, we show that a small but growing population could have a different number of cultural traits from a shrinking population with the same absolute number of individuals in some circumstances.

Exoplanet's Figure and Its Interior

NASA Astrophysics Data System (ADS)

Mian, Zhang; Cheng-li, Huang

2018-01-01

Along with the development of the observing technology, the observation and study on the exoplanets' oblateness and apsidal precession have achieved significant progress. The oblateness of an exoplanet is determined by its interior density profile and rotation period. Between its Love number k2 and core size exists obviously a negative correlation. So oblateness and k2 can well constrain its interior structure. Starting from the Lane-Emden equation, the planet models based on different polytropic indices are built. Then the flattening factors are obtained by solving the Wavre's integro-differential equation. The result shows that the smaller the polytropic index, the faster the rotation, and the larger the oblateness. We have selected 469 exoplanets, which have simultaneously the observed or estimated values of radius, mass, and orbit period from the NASA (National Aeronautics and Space Administration) Exoplanet Archive, and calculated their flattening factors under the two assumptions: tidal locking and fixed rotation period of 10.55 hours. The result shows that the flattening factors are too small to be detected under the tidal locking assumption, and that 28% of exoplanets have the flattening factors larger than 0.1 under the fixed rotation period of 10.55 hours. The Love numbers under the different polytropic models are solved by the Zharkov's approach, and the relation between k2 and core size is discussed.

Methods to achieve accurate projection of regional and global raster databases

USGS Publications Warehouse

Usery, E.L.; Seong, J.C.; Steinwand, D.R.; Finn, M.P.

2002-01-01

This research aims at building a decision support system (DSS) for selecting an optimum projection considering various factors, such as pixel size, areal extent, number of categories, spatial pattern of categories, resampling methods, and error correction methods. Specifically, this research will investigate three goals theoretically and empirically and, using the already developed empirical base of knowledge with these results, develop an expert system for map projection of raster data for regional and global database modeling. The three theoretical goals are as follows: (1) The development of a dynamic projection that adjusts projection formulas for latitude on the basis of raster cell size to maintain equal-sized cells. (2) The investigation of the relationships between the raster representation and the distortion of features, number of categories, and spatial pattern. (3) The development of an error correction and resampling procedure that is based on error analysis of raster projection.

Demographic risk factors of self-immolation: a case-control study.

PubMed

Ahmadi, Alireza; Mohammadi, Reza; Schwebel, David C; Khazaie, Habibolah; Yeganeh, Naser; Almasi, Afshin

2009-06-01

To investigate demographic risk factors for self-immolation patients. In a case-control study, 30 consecutive cases of deliberate self-inflicted burns admitted to the regional Burn centre (Imam Khomeini hospital in Kermanshah province, Iran) were compared with 30 controls who were selected from the community and matched by gender, age, and living area. All cases and controls were reviewed for demographic variables, including: age, gender, living area, family size, marital status, bearing and number of children, Body Mass Index (BMI), birth order, employment state, educational status, early school drop-out, and parent/guardian employment status. Two variables emerged as related to risk of self-immolation. Being the first or last child in family birth order was associated with increased risk of self-immolation. Moreover, among the married participants, having children was associated with decreased risk of self-immolation. The comparisons of other variables were not statistically significant. In multivariate analyses, none of the variables predicted risk for self-immolation. This study suggests that being the first or last child of a family might be a risk factor for self-immolation. For married persons, having children might serve as a protective factor from self-immolation. Other variables such as family size, marital status, number of children, BMI, employment state, educational status, early school drop-out, and parent/guardian employment status did not play a role as individually protective or risk factors for self-immolation.

Evaluation of the significance of radiographic density and size of calculi in the incidence and clinical manifestations of postlithotripsy renal hematomas.

PubMed

Orozco Fariñas, Rodolfo; Iglesias Prieto, José Ignacio; Massarrah Halabi, Jorge; Mancebo Gómez, José María; Pérez-Castro Ellendt, Enrique

2011-01-01

The present study is a continuation of an earlier article published on the incidence, clinical manifestations, treatment and risk factors associated with postlithotripsy renal hematomas (1). To assess the possible influence of the size and radiodensity of kidney stones on the incidence and clinical behavior of renal postlithotripsy hematomas. Observational prospective study of 324 renal units in the same number of patients undergoing extracorporeal renal lithotripsy. The variables "calculus size" and "radiographic calculus density" were evaluaArch. ted statistically by means of the IPSS 0.15 program on the basis of 42 postlithotripsy hematomas diagnosed and grouped according to their clinical behavior. Higher incidence of hematomas was observed in hiperdense calculi (25%) versus medium density calculi (7,4%), this difference was significant in the asymptomatic hematoma group. Calculus size was unrelated to the incidence of renal hematoma, but there was a significant association between renal hematoma and radiographic calculus density, probably due to the relation of radiographic density to chemical composition and, ultimately, to hardness and ultrastructure. Ultrastructure is yet another factor, among others, to be taken into account as a potential conditioning factor for this complication.

Ecology of exposed sandy beaches in northern Spain: Environmental factors controlling macrofauna communities

NASA Astrophysics Data System (ADS)

Lastra, M.; de La Huz, R.; Sánchez-Mata, A. G.; Rodil, I. F.; Aerts, K.; Beloso, S.; López, J.

2006-02-01

Thirty-four exposed sandy beaches on the northern coast of Spain (from 42°11' to 43°44'N, and from 2°04' to 8°52' W; ca. 1000 km) were sampled over a range of beach sizes, beach morphodynamics and exposure rates. Ten equally spaced intertidal shore levels along six replicated transects were sampled at each beach. Sediment and macrofauna samples were collected using corers to a depth of 15 cm. Morphodynamic characteristics such as the beach face slope, wave environment, exposure rates, Dean's parameter and Beach State Index were estimated. Biotic results indicated that in all the beaches the community was dominated by isopods, amphipods and polychaetes, mostly belonging to the detritivorous-opportunistic trophic group. The number of intertidal species ranged from 9 to 31, their density being between 31 and 618 individuals m - 2 , while individuals per linear metre (m - 1 ) ranged from 4962 to 17 2215. The biomass, calculated as total ash-free dry weight (AFDW) varied from 0.027 to 2.412 g m - 2 , and from 3.6 to 266.6 g m - 1 . Multiple regression analysis indicated that number of species significantly increased with proximity to the wind-driven upwelling zone located to the west, i.e., west-coast beaches hosted more species than east-coast beaches. The number of species increased with decreasing mean grain size and increasing beach length. The density of individuals m - 2 increased with decreasing mean grain size, while biomass m - 2 increased with increasing food availability estimated as chlorophyll-a concentration in the water column of the swash zone. Multiple-regression analysis indicated that chlorophyll-a in the water column increased with increasing western longitude. Additional insights provided by single-regression analysis showed a positive relationship between the number of species and chlorophyll-a, while increasing biomass occurred with increasing mean grain size of the beach. The results indicate that community characteristics in the exposed sandy beaches studied are affected by physical characteristics such as sediment size and beach length, but also by other factors dependent on coastal processes, such as food availability in the water column.

Parental and perinatal risk factors for sexual offending in men: a nationwide case-control study.

PubMed

Babchishin, K M; Seto, M C; Sariaslan, A; Lichtenstein, P; Fazel, S; Långström, N

2017-01-01

Prior studies suggest parental and perinatal risk factors are associated with later offending. It remains uncertain, however, if such risk factors are similarly related to sexual offending. We linked socio-demographic, family relations, and perinatal (obtained at birth) data from the nationwide Swedish registers from 1973 to 2009 with information on criminal convictions of cases and control subjects. Male sex offenders (n = 13 773) were matched 1:5 on birth year and county of birth in Sweden to male controls without sexual or non-sexual violent convictions. To examine risk-factor specificity for sexual offending, we also compared male violent, non-sexual offenders (n = 135 953) to controls without sexual or non-sexual violent convictions. Predictors included parental (young maternal or paternal age at son's birth, educational attainment, violent crime, psychiatric disorder, substance misuse, suicide attempt) and perinatal (number of older brothers, low Apgar score, low birth weight, being small for gestational age, congenital malformations, small head size) variables. Conditional logistic regression models found consistent patterns of statistically significant, small to moderate independent associations of parental risk factors with sons' sexual offending and non-sexual violent offending. For perinatal risk factors, patterns varied more; small for gestational age and small head size exhibited similar risk effects for both offence types whereas a higher number of older biological brothers and any congenital malformation were small, independent risk factors only for non-sexual violence. This nationwide study suggests substantial commonalities in parental and perinatal risk factors for the onset of sexual and non-sexual violent offending.

Numbers of genes in the NBS and RLK families vary by more than four-fold within a plant species and are regulated by multiple factors.

PubMed

Zhang, Meiping; Wu, Yen-Hsuan; Lee, Mi-Kyung; Liu, Yun-Hua; Rong, Ying; Santos, Teofila S; Wu, Chengcang; Xie, Fangming; Nelson, Randall L; Zhang, Hong-Bin

2010-10-01

Many genes exist in the form of families; however, little is known about their size variation, evolution and biology. Here, we present the size variation and evolution of the nucleotide-binding site (NBS)-encoding gene family and receptor-like kinase (RLK) gene family in Oryza, Glycine and Gossypium. The sizes of both families vary by numeral fold, not only among species, surprisingly, also within a species. The size variations of the gene families are shown to correlate with each other, indicating their interactions, and driven by natural selection, artificial selection and genome size variation, but likely not by polyploidization. The numbers of genes in the families in a polyploid species are similar to those of one of its diploid donors, suggesting that polyploidization plays little roles in the expansion of the gene families and that organisms tend not to maintain their 'surplus' genes in the course of evolution. Furthermore, it is found that the size variations of both gene families are associated with organisms' phylogeny, suggesting their roles in speciation and evolution. Since both selection and speciation act on organism's morphological, physiological and biological variation, our results indicate that the variation of gene family size provides a source of genetic variation and evolution.

Population size dependency of measles epidemic that was scalable from Japanese prefectures to European countries.

PubMed

Yoshikura, Hiroshi

2018-04-27

Relation between number of measles patients (y) and population size (x) was expressed by an equation y = ax s , where a is a constant and s the slope of the plot; s was 2.04-2.17 for prefectures in Japan, i.e., the number of patients was proportional to square of the prefecture population size. For European countries that joined European Union no later than 2009, the slope was 1.43-1.87. The measles' population dependency found among prefectures in Japan was thus scalable up to European countries. It was surprising because, unlike Japan, population density in EU countries was not uniform and not proportional to the population size. The population size dependency was not observed among Western Pacific and South-East Asian countries probably on account of confounding interacting socioeconomic factors. Correlation between measles incidence and birth rate, infant mortality or GDP per capita was almost insignificant.Size distribution of local infection clusters (LICs) of measles and rubella in Japan followed power law. For measles, though the population dependency remained unchanged after "elimination", there was change in the Zipf-type plot of LIC sizes. After the "elimination", LICs linked to importation-related outbreaks in less populated prefectures emerged as the top-ranked LICs.

Evidence based management of polyps of the gall bladder: A systematic review of the risk factors of malignancy.

PubMed

Bhatt, Nikita R; Gillis, Amy; Smoothey, Craig O; Awan, Faisal N; Ridgway, Paul F

2016-10-01

There are no evidence-based guidelines to dictate when Gallbladder Polyps (GBPs) of varying sizes should be resected. To identify factors that accurately predict malignant disease in GBP; to provide an evidence-based algorithm for management. A systematic review following PRISMA guidelines was performed using terms "gallbladder polyps" AND "polypoid lesion of gallbladder", from January 1993 and September 2013. Inclusion criteria required histopathological report or follow-up of 2 years. RTI-IB tool was used for quality analysis. Correlation with GBP size and malignant potential was analysed using Euclidean distance; a logistics mixed effects model was used for assessing independent risk factors for malignancy. Fifty-three articles were included in review. Data from 21 studies was pooled for analysis. Optimum size cut-off for resection of GBPs was 10 mm. Probability of malignancy is approximately zero at size <4.15 mm. Patient age >50 years, sessile and single polyps were independent risk factors for malignancy. For polyps sized 4 mm-10 mm, a risk assessment model was formulated. This review and analysis has provided an evidence-based algorithm for the management of GBPs. Longitudinal studies are needed to better understand the behaviour of polyps <10 mm, that are not at a high risk of malignancy, but may change over time. Copyright © 2016 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Assessing exposure to diesel exhaust particles: a case study.

PubMed

See, Siao Wei; Balasubramanian, Rajasekhar; Yang, Tzuo Sern; Karthikeyan, Sathrugnan

2006-11-01

The assessment of the vehicular contributions to urban pollution levels is of particular importance given the current interest in the possible adverse health effects. This study focused on human exposure to diesel-engine-derived particulate matter. Diesel vehicles are known to emit fine particulate matter (PM2.5) containing carcinogens such as polycyclic aromatic hydrocarbons (PAHs), and have therefore received considerable attention. In this study, the physical (mass and number concentration, and size distribution) and chemical (PAHs) properties were investigated at a major bus interchange in Singapore, influenced only by diesel exhausts. Number concentration and size distribution of particles were determined in real time, while the mass concentrations of PM2.5, and PAHs were measured during operating and nonoperating hours. The average mass concentrations of PM2.5 and PAHs increased by a factor of 2.34 and 5.18, respectively, during operating hours. The average number concentration was also elevated by a factor of 5.07 during operating hours. This increase in the concentration of PM2.5 particles and their chemical constituents during operating hours was attributable to diesel emissions from in-use buses based on the particle size analysis, correlation among PAHs, and the commonly used PAHs diagnostic ratios. To evaluate the potential health threat due inhalation of air pollutants released from diesel engines, the incremental lifetime cancer risk was also calculated for a maximally exposed individual. The findings indicate that the air quality at the bus interchange poses adverse health effects.

[Influencing factors of reproduction status of patients undergoing laparoscopic myomectomy].

PubMed

Song, Guang-hui; Zhang, Song-ying; Li, Bai-jia; Wei, Wei; Huang, Dong; Lin, Xiao-na; Lou, Hong-ying

2013-09-17

To explore the influencing factors of reproduction status in women undergoing laparoscopic myomectomy (LM). A total of 278 LM patients were recruited.We retrospectively reviewed the reproduction status of 87 pregnant cases after LM. The correlations of their pregnancy outcomes and such clinical profiles as age, operative techniques, biological characteristics of fibroids (number, type, size and location) were analyzed.No uterine rupture occurred during the gestation period. None of them switched to open surgery due to laparoscopic difficulties. However, one patient had a laparoscopic suture for secondary bleeding of uterine incision. At 3 months post-operation, sonography showed no heterogeneous echo, effusion and hematoma in uterine incision.Incision through uterine cavity occurred intraoperatively in 8 cases, but no intrauterine adhesion was found on hysteroscopy 3 months later. And 87 women became pregnant and the postoperative fertilization time was from 2 months to 5 years. Age influenced the postoperative pregnancy rate.Other factors such as location, number and size of fibroid had no impact on fertility. For achieving a high conception rate and guaranteeing the safety of pregnant women, a clinician should select reasonable surgical approaches, perform accurate anatomical restoration, apply strict hemostasis and choose a right time of conception.

Serological survey of Neospora caninum infection in cattle herds from Western Romania.

PubMed

Imre, Kálmán; Morariu, Sorin; Ilie, Marius S; Imre, Mirela; Ferrari, Nicola; Genchi, Claudio; Dărăbuş, Gheorghe

2012-06-01

Serum samples from 376 randomly selected adult cattle, from 25 farms located in 3 counties (Arad, Bihor, and Timiş) from western Romania, were sampled for Neospora caninum antibodies using a commercial ELISA-kit. Seroprevalence values and risk factors for neosporosis (cow age, breed, herd size, farming system, previous abortion, and number of farm dogs) were examined using a generalized linear mixed model with a binomial distribution. Overall, the seroprevalence of N. caninum was 27.7% (104/376) with a prevalence of 27.9% (24/86) in Arad, 26.9% (25/93) in Bihor, and 27.9% (55/197) in Timiş. Of 25 cattle herds, 23 were seropositive with a prevalence ranging from 10.0 to 52.2%. No correlation was found between N. caninum seropositivity and age, breed, herd size, breeding system, and previous abortion. The number of farm dogs was the only factor (P(Wald)  =  0.03) positively associated with seroprevalence in cows and can be considered the risk factor in the acquiring of infection. The present work is the first regarding serological evidence of N. caninum infection in cattle from western Romania.

Genome-Wide Chromosomal Targets of Oncogenic Transcription Factors

DTIC Science & Technology

2008-04-01

axis. (a) Comparison between STAGE and ChIP-chip when the same sample was analyzed by both methods. The gray line indicates all predicted STAGE targets...numbers of single-hit tags (Y-axis) were plotted against the frequen- cies of those tags in the random ( gray bars) and experimental (black bars) tag...size of 500 bp gave an optimal separation between random and real data. Data shown is for a window size of 500 bp. The gray bars indicate log10 of the

Breast ptosis: causes and cure.

PubMed

Rinker, Brian; Veneracion, Melissa; Walsh, Catherine P

2010-05-01

Breast ptosis is one of the most common conditions treated by plastic surgeons, but the causes are not clearly defined. A review was conducted of 132 consecutive patients presenting for breast augmentation or mastopexy. Information was obtained by chart review and telephone interview. Standardized photographs were examined to determine degree of ptosis by the Regnault classification. Of patients who had at least one pregnancy, 85% reported adverse changes in breast shape following pregnancy, 35% reported a reduction in breast size, and 30% reported an increase in size. Upon logistic regression, age, history of significant (>50 lbs) weight loss, higher body mass index, larger bra cup size, number of pregnancies, and smoking history were found to be significant risk factors for breast ptosis (P < 0.05). History of breast-feeding, weight gain during pregnancy, and lack of participation in regular upper body exercise were not found to be significant risk factors for ptosis.

Molecular-like hierarchical self-assembly of monolayers of mixtures of particles

PubMed Central

Singh, P.; Hossain, M.; Gurupatham, S. K.; Shah, K.; Amah, E.; Ju, D.; Janjua, M.; Nudurupati, S.; Fischer, I.

2014-01-01

We present a technique that uses an externally applied electric field to self-assemble monolayers of mixtures of particles into molecular-like hierarchical arrangements on fluid-liquid interfaces. The arrangements consist of composite particles (analogous to molecules) which are arranged in a pattern. The structure of a composite particle depends on factors such as the relative sizes of the particles and their polarizabilities, and the electric field intensity. If the particles sizes differ by a factor of two or more, the composite particle has a larger particle at its core and several smaller particles form a ring around it. The number of particles in the ring and the spacing between the composite particles depend on their polarizabilities and the electric field intensity. Approximately same sized particles form chains (analogous to polymeric molecules) in which positively and negatively polarized particles alternate. PMID:25510331

Numerical algorithms for scatter-to-attenuation reconstruction in PET: empirical comparison of convergence, acceleration, and the effect of subsets.

PubMed

Berker, Yannick; Karp, Joel S; Schulz, Volkmar

2017-09-01

The use of scattered coincidences for attenuation correction of positron emission tomography (PET) data has recently been proposed. For practical applications, convergence speeds require further improvement, yet there exists a trade-off between convergence speed and the risk of non-convergence. In this respect, a maximum-likelihood gradient-ascent (MLGA) algorithm and a two-branch back-projection (2BP), which was previously proposed, were evaluated. MLGA was combined with the Armijo step size rule; and accelerated using conjugate gradients, Nesterov's momentum method, and data subsets of different sizes. In 2BP, we varied the subset size, an important determinant of convergence speed and computational burden. We used three sets of simulation data to evaluate the impact of a spatial scale factor. The Armijo step size allowed 10-fold increased step sizes compared to native MLGA. Conjugate gradients and Nesterov momentum lead to slightly faster, yet non-uniform convergence; improvements were mostly confined to later iterations, possibly due to the non-linearity of the problem. MLGA with data subsets achieved faster, uniform, and predictable convergence, with a speed-up factor equivalent to the number of subsets and no increase in computational burden. By contrast, 2BP computational burden increased linearly with the number of subsets due to repeated evaluation of the objective function, and convergence was limited to the case of many (and therefore small) subsets, which resulted in high computational burden. Possibilities of improving 2BP appear limited. While general-purpose acceleration methods appear insufficient for MLGA, results suggest that data subsets are a promising way of improving MLGA performance.

Children and Adults Use Physical Size and Numerical Alliances in Third-Party Judgments of Dominance.

PubMed

Lourenco, Stella F; Bonny, Justin W; Schwartz, Bari L

2015-01-01

Humans and other social animals interact regularly with conspecifics as part of affiliative groups. Many of these interactions are cooperative, but many others involve competition for resources. Competitive exchanges are often resolved on the basis of dominance relationships, with higher-ranking individuals receiving priority access to desired goods. Although no single cue can establish permanent dominance relationships, there are some cues that predict dominance fairly reliably across context. In the present study, we focused on two such cues relevant to competing groups: (i) the physical sizes of individual members, and (ii) their relative number. Using a social competition task, we examined whether, and how, preschool-aged children and adults used differences in physical size and numerical alliances to judge which of two groups should prevail in a competitive exchange for a desired object. These judgments were made when either physical size or number differed between groups (Experiment 1), and when both were available but pitted against each other (Experiments 1 and 2). Our findings revealed that by 3 years of age, humans use multiple perceptible cues in third-party judgments of dominance. Our findings also revealed that 3-year-olds, like adults, weighted these cues flexibly according to the additional factor of overall group size, with the physical sizes of individuals determining dominance in smaller groups (e.g., 2 vs. 4 characters) and the relative number of individuals determining dominance in larger groups (e.g., 15 vs. 30 characters). Taken together, our findings suggest that a basic formula for determining dominance in competitive exchanges, which weights physical size of individuals and numerical alliances as a function of overall group size, is available to young children and appears fairly stable through to adulthood.

Reexamining Sample Size Requirements for Multivariate, Abundance-Based Community Research: When Resources are Limited, the Research Does Not Have to Be.

PubMed

Forcino, Frank L; Leighton, Lindsey R; Twerdy, Pamela; Cahill, James F

2015-01-01

Community ecologists commonly perform multivariate techniques (e.g., ordination, cluster analysis) to assess patterns and gradients of taxonomic variation. A critical requirement for a meaningful statistical analysis is accurate information on the taxa found within an ecological sample. However, oversampling (too many individuals counted per sample) also comes at a cost, particularly for ecological systems in which identification and quantification is substantially more resource consuming than the field expedition itself. In such systems, an increasingly larger sample size will eventually result in diminishing returns in improving any pattern or gradient revealed by the data, but will also lead to continually increasing costs. Here, we examine 396 datasets: 44 previously published and 352 created datasets. Using meta-analytic and simulation-based approaches, the research within the present paper seeks (1) to determine minimal sample sizes required to produce robust multivariate statistical results when conducting abundance-based, community ecology research. Furthermore, we seek (2) to determine the dataset parameters (i.e., evenness, number of taxa, number of samples) that require larger sample sizes, regardless of resource availability. We found that in the 44 previously published and the 220 created datasets with randomly chosen abundances, a conservative estimate of a sample size of 58 produced the same multivariate results as all larger sample sizes. However, this minimal number varies as a function of evenness, where increased evenness resulted in increased minimal sample sizes. Sample sizes as small as 58 individuals are sufficient for a broad range of multivariate abundance-based research. In cases when resource availability is the limiting factor for conducting a project (e.g., small university, time to conduct the research project), statistically viable results can still be obtained with less of an investment.

A method for measuring particle number emissions from vehicles driving on the road.

PubMed

Shi, J P; Harrison, R M; Evans, D E; Alam, A; Barnes, C; Carter, G

2002-01-01

Earlier research has demonstrated that the conditions of dilution of engine exhaust gases profoundly influence the size distribution and total number of particles emitted. Since real world dilution conditions are variable and therefore difficult to simulate, this research has sought to develop and validate a method for measuring particle number emissions from vehicles driving past on a road. This has been achieved successfully using carbon dioxide as a tracer of exhaust gas dilution. By subsequent adjustment of data to a constant dilution factor, it is possible to compare emissions from different vehicles using different technologies and fuels based upon real world emission data. Whilst further optimisation of the technique, especially in terms of matching the instrument response times is desirable, the measurements offer useful insights into emissions from gasoline and diesel vehicles, and the substantial proportion of particles emitted in the 3-7 nanometre size range.

Defensive responses by a social caterpillar are tailored to different predators and change with larval instar and group size

NASA Astrophysics Data System (ADS)

McClure, Melanie; Despland, Emma

2011-05-01

Gregariousness in animals is widely accepted as a behavioral adaptation for protection from predation. However, predation risk and the effectiveness of a prey's defense can be a function of several other factors, including predator species and prey size or age. The objective of this study was to determine if the gregarious habit of Malacosoma disstria caterpillars is advantageous against invertebrate natural enemies, and whether it is through dilution or cooperative defenses. We also examined the effects of larval growth and group size on the rate and success of attacks. Caterpillars of M. disstria responded with predator-specific behaviors, which led to increased survival. Evasive behaviors were used against stinkbugs, while thrashing by fourth instar caterpillars and holding on to the silk mat by second instar caterpillars was most efficient against spider attacks. Collective head flicking and biting by groups of both second and fourth instar caterpillars were observed when attacked by parasitoids. Increased larval size decreased the average number of attacks by spiders but increased the number of attacks by both stinkbugs and parasitoids. However, increased body size decreased the success rate of attacks by all three natural enemies and increased handling time for both predators. Larger group sizes did not influence the number of attacks from predators but increased the number of attacks and the number of successful attacks from parasitoids. In all cases, individual risk was lower in larger groups. Caterpillars showed collective defenses against parasitoids but not against the walking predators. These results show that caterpillars use different tactics against different natural enemies. Overall, these tactics are both more diverse and more effective in fourth instar than in second instar caterpillars, confirming that growth reduces predation risk. We also show that grouping benefits caterpillars through dilution of risk, and, in the case of parasitoids, through group defenses. The decreased tendency to aggregate in the last larval instar may therefore be linked to decreasing predation risk.

Division of overall duration of stay into operative stay and postoperative stay improves the overall estimate as a measure of quality of outcome in burn care

PubMed Central

Olofsson, Pia; Fredrikson, Mats; Sjoberg, Folke

2017-01-01

Total duration of stay adjusted for percentage of the total body surface area burned (TBSA%) is a commonly used outcome measure in burn care. However, it has been criticised as it is affected by many factors, some of which are not strictly part of burn care. A division into operative stay and postoperative stay may improve this measure. The aim was to evaluate if operative stay can serve as a more standardised measure by: comparing the variation in operative stay/TBSA% with the variation in total stay/TBSA%, and to study different factors associated with operative stay and postoperative stay. Patients and methods Surgically managed burn patients admitted between 2010–14 were included. Operative stay was defined as the time from admission until the last operation, postoperative stay as the time from the last operation until discharge. The difference in variation was analysed with F-test. A retrospective review of medical records was done to explore reasons for extended postoperative stay. Multivariable regression was used to assess factors associated with operative stay and postoperative stay. Results Operative stay/TBSA% showed less variation than total duration/TBSA% (F test = 2.38, p<0.01). The size of the burn, and the number of operations, were the independent factors that influenced operative stay (R2 0.65). Except for the size of the burn other factors were associated with duration of postoperative stay: wound related, psychological and other medical causes, advanced medical support, and accommodation arrangements before discharge, of which the two last were the most important with an increase of (mean) 12 and 17 days (p<0.001, R2 0.51). Conclusion Adjusted operative stay showed less variation than total hospital stay and thus can be considered a more accurate outcome measure for surgically managed burns. The size of burn and number of operations are the factors affecting this outcome measure. PMID:28362844

Stability of radiomic features in CT perfusion maps

NASA Astrophysics Data System (ADS)

Bogowicz, M.; Riesterer, O.; Bundschuh, R. A.; Veit-Haibach, P.; Hüllner, M.; Studer, G.; Stieb, S.; Glatz, S.; Pruschy, M.; Guckenberger, M.; Tanadini-Lang, S.

2016-12-01

This study aimed to identify a set of stable radiomic parameters in CT perfusion (CTP) maps with respect to CTP calculation factors and image discretization, as an input for future prognostic models for local tumor response to chemo-radiotherapy. Pre-treatment CTP images of eleven patients with oropharyngeal carcinoma and eleven patients with non-small cell lung cancer (NSCLC) were analyzed. 315 radiomic parameters were studied per perfusion map (blood volume, blood flow and mean transit time). Radiomics robustness was investigated regarding the potentially standardizable (image discretization method, Hounsfield unit (HU) threshold, voxel size and temporal resolution) and non-standardizable (artery contouring and noise threshold) perfusion calculation factors using the intraclass correlation (ICC). To gain added value for our model radiomic parameters correlated with tumor volume, a well-known predictive factor for local tumor response to chemo-radiotherapy, were excluded from the analysis. The remaining stable radiomic parameters were grouped according to inter-parameter Spearman correlations and for each group the parameter with the highest ICC was included in the final set. The acceptance level was 0.9 and 0.7 for the ICC and correlation, respectively. The image discretization method using fixed number of bins or fixed intervals gave a similar number of stable radiomic parameters (around 40%). The potentially standardizable factors introduced more variability into radiomic parameters than the non-standardizable ones with 56-98% and 43-58% instability rates, respectively. The highest variability was observed for voxel size (instability rate  >97% for both patient cohorts). Without standardization of CTP calculation factors none of the studied radiomic parameters were stable. After standardization with respect to non-standardizable factors ten radiomic parameters were stable for both patient cohorts after correction for inter-parameter correlations. Voxel size, image discretization, HU threshold and temporal resolution have to be standardized to build a reliable predictive model based on CTP radiomics analysis.

Problems and Trends Regarding Vocational Teachers in China

ERIC Educational Resources Information Center

Kuang, Ying

2014-01-01

At present, China's vocational education system is undergoing a transition process from growing in size to improving in quality. Teacher and teaching force issues are a bottleneck and critical factor that will determine whether the transformation will be successful. The real-world problems of the number, deployment, capacity, and training systems…

Inhibition in Dot Comparison Tasks

ERIC Educational Resources Information Center

Clayton, Sarah; Gilmore, Camilla

2015-01-01

Dot comparison tasks are commonly used to index an individual's Approximate Number System (ANS) acuity, but the cognitive processes involved in completing these tasks are poorly understood. Here, we investigated how factors including numerosity ratio, set size and visual cues influence task performance. Forty-four children aged 7-9 years completed…

QEEN Workshop: "Quantifying Exposure to Engineered Nano-materials from Manufactured Products": Write Up Biological Tissues and Media

EPA Science Inventory

The measurement and characterization of nanomaterials in biological tissues is complicated by a number of factors including: the sensitivity of the assay to small sized particles or low concentrations of materials; the ability to distinguish different forms and transformations of...

The predictive efficiency of school bullying versus later offending: a systematic/meta-analytic review of longitudinal studies.

PubMed

Ttofi, Maria M; Farrington, David P; Lösel, Friedrich; Loeber, Rolf

2011-04-01

Although bullying and delinquency share similar risk factors, no previous systematic review has ever been conducted to examine possible links between school bullying and criminal offending later in life. To investigate the extent to which bullying perpetration at school predicts offending later in life, and whether this relation holds after controlling for other major childhood risk factors. Results are based on a thorough systematic review and meta-analysis of studies measuring school bullying and later offending. Effect sizes are based on both published and unpublished studies; longitudinal investigators of 28 studies have conducted specific analyses for our review. The probability of offending up to 11 years later was much higher for school bullies than for non-involved students [odds ratio (OR) = 2.50; 95% confidence interval (CI): 2.03-3.08]. Bullying perpetration was a significant risk factor for later offending, even after controlling for major childhood risk factors (OR = 1.82, 95% CI: 1.55-2.14). Effect sizes were smaller when the follow-up period was longer and larger when bullying was assessed in older children. The age of participants when outcome measures were taken was negatively related with effect sizes. Finally, the summary effect size did not decrease much as the number of controlled risk factors increased. School bullying is a strong and specific risk factor for later offending. Effective anti-bullying programmes should be promoted, and could be viewed as a form of early crime prevention. Such programmes would have a high benefit : cost ratio. Copyright © 2011 John Wiley & Sons, Ltd.

Particle and gaseous emissions from individual diesel and CNG buses

NASA Astrophysics Data System (ADS)

Hallquist, Å. M.; Jerksjö, M.; Fallgren, H.; Westerlund, J.; Sjödin, Å.

2013-05-01

In this study size-resolved particle and gaseous emissions from 28 individual diesel-fuelled and 7 compressed natural gas (CNG)-fuelled buses, selected from an in-use bus fleet, were characterised for real-world dilution scenarios. The method used was based on using CO2 as a tracer of exhaust gas dilution. The particles were sampled by using an extractive sampling method and analysed with high time resolution instrumentation EEPS (10 Hz) and CO2 with a non-dispersive infrared gas analyser (LI-840, LI-COR Inc. 1 Hz). The gaseous constituents (CO, HC and NO) were measured by using a remote sensing device (AccuScan RSD 3000, Environmental System Products Inc.). Nitrogen oxides, NOx, were estimated from NO by using default NO2/NOx ratios from the road vehicle emission model HBEFA3.1. The buses studied were diesel-fuelled Euro III-V and CNG-fuelled Enhanced Environmentally Friendly Vehicles (EEVs) with different after-treatment, including selective catalytic reduction (SCR), exhaust gas recirculation (EGR) and with and without diesel particulate filter (DPF). The primary driving mode applied in this study was accelerating mode. However, regarding the particle emissions also a constant speed mode was analysed. The investigated CNG buses emitted on average a higher number of particles but less mass compared to the diesel-fuelled buses. Emission factors for number of particles (EFPN) were EFPN, DPF = 4.4 ± 3.5 × 1014, EFPN, no DPF = 2.1 ± 1.0 × 1015 and EFPN, CNG = 7.8 ± 5.7 ×1015 kg fuel-1. In the accelerating mode, size-resolved emission factors (EFs) showed unimodal number size distributions with peak diameters of 70-90 nm and 10 nm for diesel and CNG buses, respectively. For the constant speed mode, bimodal average number size distributions were obtained for the diesel buses with peak modes of ~10 nm and ~60 nm. Emission factors for NOx expressed as NO2 equivalents for the diesel buses were on average 27 ± 7 g (kg fuel)-1 and for the CNG buses 41 ± 26 g (kg fuel)-1. An anti-relationship between EFNOx and EFPM was observed especially for buses with no DPF, and there was a positive relationship between EFPM and EFCO.

Evaluation of the Risk Factors for a Rotator Cuff Retear After Repair Surgery.

PubMed

Lee, Yeong Seok; Jeong, Jeung Yeol; Park, Chan-Deok; Kang, Seung Gyoon; Yoo, Jae Chul

2017-07-01

A retear is a significant clinical problem after rotator cuff repair. However, no study has evaluated the retear rate with regard to the extent of footprint coverage. To evaluate the preoperative and intraoperative factors for a retear after rotator cuff repair, and to confirm the relationship with the extent of footprint coverage. Cohort study; Level of evidence, 3. Data were retrospectively collected from 693 patients who underwent arthroscopic rotator cuff repair between January 2006 and December 2014. All repairs were classified into 4 types of completeness of repair according to the amount of footprint coverage at the end of surgery. All patients underwent magnetic resonance imaging (MRI) after a mean postoperative duration of 5.4 months. Preoperative demographic data, functional scores, range of motion, and global fatty degeneration on preoperative MRI and intraoperative variables including the tear size, completeness of rotator cuff repair, concomitant subscapularis repair, number of suture anchors used, repair technique (single-row or transosseous-equivalent double-row repair), and surgical duration were evaluated. Furthermore, the factors associated with failure using the single-row technique and transosseous-equivalent double-row technique were analyzed separately. The retear rate was 7.22%. Univariate analysis revealed that rotator cuff retears were affected by age; the presence of inflammatory arthritis; the completeness of rotator cuff repair; the initial tear size; the number of suture anchors; mean operative time; functional visual analog scale scores; Simple Shoulder Test findings; American Shoulder and Elbow Surgeons scores; and fatty degeneration of the supraspinatus, infraspinatus, and subscapularis. Multivariate logistic regression analysis revealed patient age, initial tear size, and fatty degeneration of the supraspinatus as independent risk factors for a rotator cuff retear. Multivariate logistic regression analysis of the single-row group revealed patient age and fatty degeneration of the supraspinatus as independent risk factors for a rotator cuff retear. Multivariate logistic regression analysis of the transosseous-equivalent double-row group revealed a frozen shoulder as an independent risk factor for a rotator cuff retear. Our results suggest that patient age, initial tear size, and fatty degeneration of the supraspinatus are independent risk factors for a rotator cuff retear, whereas the completeness of rotator cuff repair based on the extent of footprint coverage and repair technique are not.

Spectral distribution of particle fluence in small field detectors and its implication on small field dosimetry.

PubMed

Benmakhlouf, Hamza; Andreo, Pedro

2017-02-01

Correction factors for the relative dosimetry of narrow megavoltage photon beams have recently been determined in several publications. These corrections are required because of the several small-field effects generally thought to be caused by the lack of lateral charged particle equilibrium (LCPE) in narrow beams. Correction factors for relative dosimetry are ultimately necessary to account for the fluence perturbation caused by the detector. For most small field detectors the perturbation depends on field size, resulting in large correction factors when the field size is decreased. In this work, electron and photon fluence differential in energy will be calculated within the radiation sensitive volume of a number of small field detectors for 6 MV linear accelerator beams. The calculated electron spectra will be used to determine electron fluence perturbation as a function of field size and its implication on small field dosimetry analyzed. Fluence spectra were calculated with the user code PenEasy, based on the PENELOPE Monte Carlo system. The detectors simulated were one liquid ionization chamber, two air ionization chambers, one diamond detector, and six silicon diodes, all manufactured either by PTW or IBA. The spectra were calculated for broad (10 cm × 10 cm) and narrow (0.5 cm × 0.5 cm) photon beams in order to investigate the field size influence on the fluence spectra and its resulting perturbation. The photon fluence spectra were used to analyze the impact of absorption and generation of photons. These will have a direct influence on the electrons generated in the detector radiation sensitive volume. The electron fluence spectra were used to quantify the perturbation effects and their relation to output correction factors. The photon fluence spectra obtained for all detectors were similar to the spectrum in water except for the shielded silicon diodes. The photon fluence in the latter group was strongly influenced, mostly in the low-energy region, by photoabsorption in the high-Z shielding material. For the ionization chambers and the diamond detector, the electron fluence spectra were found to be similar to that in water, for both field sizes. In contrast, electron spectra in the silicon diodes were much higher than that in water for both field sizes. The estimated perturbations of the fluence spectra for the silicon diodes were 11-21% for the large fields and 14-27% for the small fields. These perturbations are related to the atomic number, density and mean excitation energy (I-value) of silicon, as well as to the influence of the "extracameral"' components surrounding the detector sensitive volume. For most detectors the fluence perturbation was also found to increase when the field size was decreased, in consistency with the increased small-field effects observed for the smallest field sizes. The present work improves the understanding of small-field effects by relating output correction factors to spectral fluence perturbations in small field detectors. It is shown that the main reasons for the well-known small-field effects in silicon diodes are the high-Z and density of the "extracameral" detector components and the high I-value of silicon relative to that of water and diamond. Compared to these parameters, the density and atomic number of the radiation sensitive volume material play a less significant role. © 2016 American Association of Physicists in Medicine.

Multilevel Factorial Experiments for Developing Behavioral Interventions: Power, Sample Size, and Resource Considerations†

PubMed Central

Dziak, John J.; Nahum-Shani, Inbal; Collins, Linda M.

2012-01-01

Factorial experimental designs have many potential advantages for behavioral scientists. For example, such designs may be useful in building more potent interventions, by helping investigators to screen several candidate intervention components simultaneously and decide which are likely to offer greater benefit before evaluating the intervention as a whole. However, sample size and power considerations may challenge investigators attempting to apply such designs, especially when the population of interest is multilevel (e.g., when students are nested within schools, or employees within organizations). In this article we examine the feasibility of factorial experimental designs with multiple factors in a multilevel, clustered setting (i.e., of multilevel multifactor experiments). We conduct Monte Carlo simulations to demonstrate how design elements such as the number of clusters, the number of lower-level units, and the intraclass correlation affect power. Our results suggest that multilevel, multifactor experiments are feasible for factor-screening purposes, because of the economical properties of complete and fractional factorial experimental designs. We also discuss resources for sample size planning and power estimation for multilevel factorial experiments. These results are discussed from a resource management perspective, in which the goal is to choose a design that maximizes the scientific benefit using the resources available for an investigation. PMID:22309956

Airborne emission measurements of SO2, NOx and particles from individual ships using sniffer technique

NASA Astrophysics Data System (ADS)

Beecken, J.; Mellqvist, J.; Salo, K.; Ekholm, J.; Jalkanen, J.-P.

2013-12-01

A dedicated system for airborne ship emission measurements of SO2, NOx and particles has been developed and used from several small aircrafts. The system has been adapted for fast response measurements at 1 Hz and the use of several of the instruments is unique. The uncertainty of the given data is about 20.3% for SO2 and 23.8% for NOx emission factors. Multiple measurements of 158 ships measured from the air on the Baltic and North Sea during 2011 and 2012 show emission factors of 18.8 ± 6.5 g kgfuel-1, 66.6 ± 23.4 g kgfuel-1, and 1.8 ± 1.3 × 1016 particles kgfuel-1 for SO2, NOx and particle number respectively. The particle size distributions were measured for particle diameters between 15 and 560 nm. The mean sizes of the particles are between 50 and 62 nm dependent on the distance to the source and the number size distribution is mono-modal. Concerning the sulfur fuel content 85% of the ships comply with the IMO limits. The sulfur emission has decreased compared to earlier measurements from 2007 to 2009. The presented method can be implemented for regular ship compliance monitoring.

Social network, recovery attitudes and internal stigma among those with serious mental illness.

PubMed

Cullen, Bernadette Am; Mojtabai, Ramin; Bordbar, Elahe; Everett, Anita; Nugent, Katie L; Eaton, William W

2017-08-01

Social network size and strength is an important determinant of overall health. This study describes the extent and strength of the social network among a sample of individuals with serious mental illness (SMI) and explores the relationship between an individual's social network and their experience of internal stigma and recovery attitudes. Over a 2-year period, consecutive new patients with SMI attending two community mental health clinics were recruited and interviewed using a comprehensive battery of assessments including assessment of internalized stigma, recovery attitudes and symptom severity. Among the 271 patients interviewed, social network size was small across all diagnostic categories. In adjusted results, the number of friends and support from relatives and friends was significantly related to the personal confidence and hope recovery attitude ( p < .05). The number of relatives and friends and support from relatives was significantly related to internalized stigma ( p < .05). Frequency of contact with relatives or friends was not related to either recovery factors or internalized stigma. There is a significant positive relationship between the size and perceived strength of an individual's social network and internalized stigma and some recovery attitudes. Clinical programs that address any of these factors could potentially improve outcomes for this population.

Multilevel factorial experiments for developing behavioral interventions: power, sample size, and resource considerations.

PubMed

Dziak, John J; Nahum-Shani, Inbal; Collins, Linda M

2012-06-01

Factorial experimental designs have many potential advantages for behavioral scientists. For example, such designs may be useful in building more potent interventions by helping investigators to screen several candidate intervention components simultaneously and to decide which are likely to offer greater benefit before evaluating the intervention as a whole. However, sample size and power considerations may challenge investigators attempting to apply such designs, especially when the population of interest is multilevel (e.g., when students are nested within schools, or when employees are nested within organizations). In this article, we examine the feasibility of factorial experimental designs with multiple factors in a multilevel, clustered setting (i.e., of multilevel, multifactor experiments). We conduct Monte Carlo simulations to demonstrate how design elements-such as the number of clusters, the number of lower-level units, and the intraclass correlation-affect power. Our results suggest that multilevel, multifactor experiments are feasible for factor-screening purposes because of the economical properties of complete and fractional factorial experimental designs. We also discuss resources for sample size planning and power estimation for multilevel factorial experiments. These results are discussed from a resource management perspective, in which the goal is to choose a design that maximizes the scientific benefit using the resources available for an investigation. (c) 2012 APA, all rights reserved

Annual plants change in size over a century of observations.

PubMed

Leger, Elizabeth A

2013-07-01

Studies have documented changes in animal body sizes over the last century, but very little is known about changes in plant sizes, even though reduced plant productivity is potentially responsible for declines in size of other organisms. Here, I ask whether warming trends in the Great Basin have affected plant size by measuring specimens preserved on herbarium sheets collected between 1893 and 2011. I asked how maximum and minimum temperatures, precipitation, and the Pacific Decadal Oscillation (PDO) in the year of collection affected plant height, leaf size, and flower number, and asked whether changes in climate resulted in decreasing sizes for seven annual forbs. Species had contrasting responses to climate factors, and would not necessarily be expected to respond in parallel to climatic shifts. There were generally positive relationships between plant size and increased minimum and maximum temperatures, which would have been predicted to lead to small increases in plant sizes over the observation period. While one species increased in size and flower number over the observation period, five of the seven species decreased in plant height, four of these decreased in leaf size, and one species also decreased in flower production. One species showed no change. The mechanisms behind these size changes are unknown, and the limited data available on these species (germination timing, area of occupancy, relative abundance) did not explain why some species shrank while others grew or did not change in size over time. These results show that multiple annual forbs are decreasing in size, but that even within the same functional group, species may have contrasting responses to similar environmental stimuli. Changes in plant size could have cascading effects on other members of these communities, and differential responses to directional change may change the composition of plant communities over time. © 2013 Blackwell Publishing Ltd.

Assessment of sampling stability in ecological applications of discriminant analysis

USGS Publications Warehouse

Williams, B.K.; Titus, K.

1988-01-01

A simulation study was undertaken to assess the sampling stability of the variable loadings in linear discriminant function analysis. A factorial design was used for the factors of multivariate dimensionality, dispersion structure, configuration of group means, and sample size. A total of 32,400 discriminant analyses were conducted, based on data from simulated populations with appropriate underlying statistical distributions. A review of 60 published studies and 142 individual analyses indicated that sample sizes in ecological studies often have met that requirement. However, individual group sample sizes frequently were very unequal, and checks of assumptions usually were not reported. The authors recommend that ecologists obtain group sample sizes that are at least three times as large as the number of variables measured.

Generation of random microstructures and prediction of sound velocity and absorption for open foams with spherical pores.

PubMed

Zieliński, Tomasz G

2015-04-01

This paper proposes and discusses an approach for the design and quality inspection of the morphology dedicated for sound absorbing foams, using a relatively simple technique for a random generation of periodic microstructures representative for open-cell foams with spherical pores. The design is controlled by a few parameters, namely, the total open porosity and the average pore size, as well as the standard deviation of pore size. These design parameters are set up exactly and independently, however, the setting of the standard deviation of pore sizes requires some number of pores in the representative volume element (RVE); this number is a procedure parameter. Another pore structure parameter which may be indirectly affected is the average size of windows linking the pores, however, it is in fact weakly controlled by the maximal pore-penetration factor, and moreover, it depends on the porosity and pore size. The proposed methodology for testing microstructure-designs of sound absorbing porous media applies the multi-scale modeling where some important transport parameters-responsible for sound propagation in a porous medium-are calculated from microstructure using the generated RVE, in order to estimate the sound velocity and absorption of such a designed material.

Factors that affect the fatigue strength of power transmission shafting and their impact on design

NASA Technical Reports Server (NTRS)

Leowenthal, S. H.

1986-01-01

A long standing objective in the design of power transmission shafting is to eliminate excess shaft material without compromising operational reliability. A shaft design method is presented which accounts for variable amplitude loading histories and their influence on limited life designs. The effects of combined bending and torsional loading are considered along with a number of application factors known to influence the fatigue strength of shafting materials. Among the factors examined are surface condition, size, stress concentration, residual stress and corrosion fatigue.

Influence of age and selected environmental factors on reproductive performance of canvasbacks

USGS Publications Warehouse

Serie, Jerome R.; Trauger, David L.; Austin, Jane E.

1992-01-01

Age, productivity, and other factors affecting breeding performance of canvasbacks (Aythya valisineria) are poorly understood. Consequently, we tested whether reproductive performance of female canvasbacks varied with age and selected environmental factors in southwestern Manitoba from 1974 to 1980. Neither clutch size, nest parasitism, nest success, nor the number of ducklings/brood varied with age. Return rates, nest initiation dates, renesting, and hen success were age-related. Return rates averaged 21% for second-year (SY) and 69% for after-second-year (ASY) females (58% for third-year and 79% for after-third-year females). Additionally, water conditions and spring temperatures influenced chronology of arrival, timing of nesting, and reproductive success. Nest initiation by birds of all ages was affected by minimum April temperatures. Clutch size was higher in nests initiated earlier. Interspecific nest parasitism did not affect clutch size, nest success, hen success, or hatching success. Nest success was lower in dry years (17%) than in moderately wet (54%) or wet (60%) years. Nests per female were highest during wet years. No nests of SY females were found in dry years. In years of moderate to good wetland conditions, females of all ages nested. Predation was the primary factor influencing nest success. Hen success averaged 58% over all years. The number of ducklings surviving 20 days averaged 4.7/brood. Because SY females have lower return rates and hen success than ASY females, especially during drier years, management to increase canvasback populations might best be directed to increasing first year recruitment (no. of females returning to breed) and to increasing overall breeding success by reducing predation and enhancing local habitat conditions during nesting.

Factors influencing nesting success of burrowing owls in southeastern Idaho

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

Gleason, R.S.; Johnson, D.R.

1985-01-31

A burrowing owl (Athene cunicularia) population nesting on the Idaho National Engineering Laboratory (INEL) in southeastern Idaho utilized burrows excavated by badgers (Taxidea taxus) or natural cavities in lava flows as nesting sites. The size of the population was small (N = 13-14 pairs) in relation to the number of available nesting sites, suggesting that factors other than burrow availability limited this population. Rodents and Jerusalem crickets (Stenopelmatus fuscus) represented the primary prey utilized during the nesting season. This population demonstrated both a numerical (brood size) and functional (dietary) response to a decrease in the density of three species ofmore » rodents on the INEL during a drought in 1977. 11 references, 1 figure, 2 table.« less

Small Gallstone Size and Delayed Cholecystectomy Increase the Risk of Recurrent Pancreatobiliary Complications After Resolved Acute Biliary Pancreatitis.

PubMed

Kim, Sung Bum; Kim, Tae Nyeun; Chung, Hyun Hee; Kim, Kook Hyun

2017-03-01

Acute biliary pancreatitis (ABP) is a severe complication of gallstone disease with considerable mortality, and its recurrence rate is reported as 50-90% for ABP patients who do not undergo cholecystectomy. However, the incidence of and risk factors for recurrent pancreatobiliary complications after the initial improvement of ABP are not well established in the literature. The aims of this study were to determine the risk factors for recurrent pancreatobiliary complications and to compare the outcomes between early (within 2 weeks after onset of pancreatitis) and delayed cholecystectomy in patients with ABP. Patients diagnosed with ABP at Yeungnam University Hospital from January 2004 to July 2016 were retrospectively reviewed. The following risk factors for recurrent pancreatobiliary complications (acute pancreatitis, acute cholecystitis, and acute cholangitis) were analyzed: demographic characteristics, laboratory data, size and number of gallstones, severity of pancreatitis, endoscopic sphincterotomy, and timing of cholecystectomy. Patients were categorized into two groups: patients with recurrent pancreatobiliary complications (Group A) and patients without pancreatobiliary complications (Group B). Of the total 290 patients with ABP (age 66.8 ± 16.0 years, male 47.9%), 56 (19.3%) patients developed recurrent pancreatobiliary complications, of which 35 cases were acute pancreatitis, 11 cases were acute cholecystitis, and 10 cases were acute cholangitis. Endoscopic sphincterotomy and cholecystectomy were performed in 134 (46.2%) patients and 95 (32.8%) patients, respectively. Age, sex, BMI, diabetes, number of stone, severity of pancreatitis, and laboratory data were not significantly correlated with recurrent pancreatobiliary complications. The risk of recurrent pancreatobiliary complications was significantly increased in the delayed cholecystectomy group compared with the early cholecystectomy group (45.5 vs. 5.0%, p < 0.001). Based on the multivariate logistic regression analyses, two factors, size of gallstone less than or equal to 5 mm and delayed cholecystectomy, were found as risk factors associated with recurrent pancreatobiliary complications. The incidence of recurrent pancreatobiliary complications was 19.3% and was significantly increased in patients with size of gallstone less than or equal to 5 mm and in those who underwent delayed cholecystectomy.

Analytic calculation of finite-population reproductive numbers for direct- and vector-transmitted diseases with homogeneous mixing.

PubMed

Keegan, Lindsay; Dushoff, Jonathan

2014-05-01

The basic reproductive number, R0, provides a foundation for evaluating how various factors affect the incidence of infectious diseases. Recently, it has been suggested that, particularly for vector-transmitted diseases, R0 should be modified to account for the effects of finite host population within a single disease transmission generation. Here, we use a transmission factor approach to calculate such "finite-population reproductive numbers," under the assumption of homogeneous mixing, for both vector-borne and directly transmitted diseases. In the case of vector-borne diseases, we estimate finite-population reproductive numbers for both host-to-host and vector-to-vector generations, assuming that the vector population is effectively infinite. We find simple, interpretable formulas for all three of these quantities. In the direct case, we find that finite-population reproductive numbers diverge from R0 before R0 reaches half of the population size. In the vector-transmitted case, we find that the host-to-host number diverges at even lower values of R0, while the vector-to-vector number diverges very little over realistic parameter ranges.

Large-Scale High-Resolution Cylinder Wake Measurements in a Wind Tunnel using Tomographic PIV with sCMOS Cameras

NASA Astrophysics Data System (ADS)

Michaelis, Dirk; Schroeder, Andreas

2012-11-01

Tomographic PIV has triggered vivid activity, reflected in a large number of publications, covering both: development of the technique and a wide range of fluid dynamic experiments. Maturing of tomo PIV allows the application in medium to large scale wind tunnels. Limiting factor for wind tunnel application is the small size of the measurement volume, being typically about of 50 × 50 × 15 mm3. Aim of this study is the optimization towards large measurement volumes and high spatial resolution performing cylinder wake measurements in a 1 meter wind tunnel. Main limiting factors for the volume size are the laser power and the camera sensitivity. So, a high power laser with 800 mJ per pulse is used together with low noise sCMOS cameras, mounted in forward scattering direction to gain intensity due to the Mie scattering characteristics. A mirror is used to bounce the light back, to have all cameras in forward scattering. Achievable particle density is growing with number of cameras, so eight cameras are used for a high spatial resolution. Optimizations lead to volume size of 230 × 200 × 52 mm3 = 2392 cm3, more than 60 times larger than previously. 281 × 323 × 68 vectors are calculated with spacing of 0.76 mm. The achieved measurement volume size and spatial resolution is regarded as a major step forward in the application of tomo PIV in wind tunnels. Supported by EU-project: no. 265695.

Uncertainty in Modeling Dust Mass Balance and Radiative Forcing from Size Parameterization

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

Zhao, Chun; Chen, Siyu; Leung, Lai-Yung R.

2013-11-05

This study examines the uncertainties in simulating mass balance and radiative forcing of mineral dust due to biases in the aerosol size parameterization. Simulations are conducted quasi-globally (180oW-180oE and 60oS-70oN) using the WRF24 Chem model with three different approaches to represent aerosol size distribution (8-bin, 4-bin, and 3-mode). The biases in the 3-mode or 4-bin approaches against a relatively more accurate 8-bin approach in simulating dust mass balance and radiative forcing are identified. Compared to the 8-bin approach, the 4-bin approach simulates similar but coarser size distributions of dust particles in the atmosphere, while the 3-mode pproach retains more finemore » dust particles but fewer coarse dust particles due to its prescribed og of each mode. Although the 3-mode approach yields up to 10 days longer dust mass lifetime over the remote oceanic regions than the 8-bin approach, the three size approaches produce similar dust mass lifetime (3.2 days to 3.5 days) on quasi-global average, reflecting that the global dust mass lifetime is mainly determined by the dust mass lifetime near the dust source regions. With the same global dust emission (~6000 Tg yr-1), the 8-bin approach produces a dust mass loading of 39 Tg, while the 4-bin and 3-mode approaches produce 3% (40.2 Tg) and 25% (49.1 Tg) higher dust mass loading, respectively. The difference in dust mass loading between the 8-bin approach and the 4-bin or 3-mode approaches has large spatial variations, with generally smaller relative difference (<10%) near the surface over the dust source regions. The three size approaches also result in significantly different dry and wet deposition fluxes and number concentrations of dust. The difference in dust aerosol optical depth (AOD) (a factor of 3) among the three size approaches is much larger than their difference (25%) in dust mass loading. Compared to the 8-bin approach, the 4-bin approach yields stronger dust absorptivity, while the 3-mode approach yields weaker dust absorptivity. Overall, on quasi-global average, the three size parameterizations result in a significant difference of a factor of 2~3 in dust surface cooling (-1.02~-2.87 W m-2) and atmospheric warming (0.39~0.96 W m-2) and in a tremendous difference of a factor of ~10 in dust TOA cooling (-0.24~-2.20 W m-2). An uncertainty of a factor of 2 is quantified in dust emission estimation due to the different size parameterizations. This study also highlights the uncertainties in modeling dust mass and number loading, deposition fluxes, and radiative forcing resulting from different size parameterizations, and motivates further investigation of the impact of size parameterizations on modeling dust impacts on air quality, climate, and ecosystem.« less

What is the optimum sample size for the study of peatland testate amoeba assemblages?

PubMed

Mazei, Yuri A; Tsyganov, Andrey N; Esaulov, Anton S; Tychkov, Alexander Yu; Payne, Richard J

2017-10-01

Testate amoebae are widely used in ecological and palaeoecological studies of peatlands, particularly as indicators of surface wetness. To ensure data are robust and comparable it is important to consider methodological factors which may affect results. One significant question which has not been directly addressed in previous studies is how sample size (expressed here as number of Sphagnum stems) affects data quality. In three contrasting locations in a Russian peatland we extracted samples of differing size, analysed testate amoebae and calculated a number of widely-used indices: species richness, Simpson diversity, compositional dissimilarity from the largest sample and transfer function predictions of water table depth. We found that there was a trend for larger samples to contain more species across the range of commonly-used sample sizes in ecological studies. Smaller samples sometimes failed to produce counts of testate amoebae often considered minimally adequate. It seems likely that analyses based on samples of different sizes may not produce consistent data. Decisions about sample size need to reflect trade-offs between logistics, data quality, spatial resolution and the disturbance involved in sample extraction. For most common ecological applications we suggest that samples of more than eight Sphagnum stems are likely to be desirable. Copyright © 2017 Elsevier GmbH. All rights reserved.

Processing of Intentional and Automatic Number Magnitudes in Children Born Prematurely: Evidence From fMRI

PubMed Central

Klein, Elise; Moeller, Korbinian; Kiechl-Kohlendorfer, Ursula; Kremser, Christian; Starke, Marc; Cohen Kadosh, Roi; Pupp-Peglow, Ulrike; Schocke, Michael; Kaufmann, Liane

2014-01-01

This study examined the neural correlates of intentional and automatic number processing (indexed by number comparison and physical Stroop task, respectively) in 6- and 7-year-old children born prematurely. Behavioral results revealed significant numerical distance and size congruity effects. Imaging results disclosed (1) largely overlapping fronto-parietal activation for intentional and automatic number processing, (2) a frontal to parietal shift of activation upon considering the risk factors gestational age and birth weight, and (3) a task-specific link between math proficiency and functional magnetic resonance imaging (fMRI) signal within distinct regions of the parietal lobes—indicating commonalities but also specificities of intentional and automatic number processing. PMID:25090014

Bats adjust their pulse emission rates with swarm size in the field.

PubMed

Lin, Yuan; Abaid, Nicole; Müller, Rolf

2016-12-01

Flying in swarms, e.g., when exiting a cave, could pose a problem to bats that use an active biosonar system because the animals could risk jamming each other's biosonar signals. Studies from current literature have found different results with regard to whether bats reduce or increase emission rate in the presence of jamming ultrasound. In the present work, the number of Eastern bent-wing bats (Miniopterus fuliginosus) that were flying inside a cave during emergence was estimated along with the number of signal pulses recorded. Over the range of average bat numbers present in the recording (0 to 14 bats), the average number of detected pulses per bat increased with the average number of bats. The result was interpreted as an indication that the Eastern bent-wing bats increased their emission rate and/or pulse amplitude with swarm size on average. This finding could be explained by the hypothesis that the bats might not suffer from substantial jamming probabilities under the observed density regimes, so jamming might not have been a limiting factor for their emissions. When jamming did occur, the bats could avoid it through changing the pulse amplitude and other pulse properties such as duration or frequency, which has been suggested by other studies. More importantly, the increased biosonar activities may have addressed a collision-avoidance challenge that was posed by the increased swarm size.

Does apparent size capture attention in visual search? Evidence from the Muller-Lyer illusion.

PubMed

Proulx, Michael J; Green, Monique

2011-11-23

Is perceived size a crucial factor for the bottom-up guidance of attention? Here, a visual search experiment was used to examine whether an irrelevantly longer object can capture attention when participants were to detect a vertical target item. The longer object was created by an apparent size manipulation, the Müller-Lyer illusion; however, all objects contained the same number of pixels. The vertical target was detected more efficiently when it was also perceived as the longer item that was defined by apparent size. Further analysis revealed that the longer Müller-Lyer object received a greater degree of attentional priority than published results for other features such as retinal size, luminance contrast, and the abrupt onset of a new object. The present experiment has demonstrated for the first time that apparent size can capture attention and, thus, provide bottom-up guidance on the basis of perceived salience.

Study on emission characteristics of hybrid bus under driving cycles in typical Chinese city

NASA Astrophysics Data System (ADS)

Xie, Yongdong; Xu, Guangju

2017-09-01

In this study, hybrid city bus was taken as the research object, through the vehicle drum test, the vehicle emissions of hybrid bus, the transient emissions of gas pollutants, as well as the particle size and number distribution were surveyed. The results of the studies are listed as follows: First, compared to traditional fuel bus, hybrid bus could reduce about 44% of the NOx emissions, 33% of the total hydrocarbon emissions, and 51% of the particles emissions. Furthermore, the distribution of particles number concentration of test vehicle became high in middle and low in both sides. More specifically, the particle number concentration was mainly concentrated in the range from 0.021 to 0.755μm, the maximum was 0.2μm, and particle size of particulate matter (PM) less than 1.2μm accounted for 95% of the total number concentration. Particulate mass concentration was increased with increment of particle size, and the maximum of particulate mass (PM) concentration was 6.2μm. On average, whether traditional fuel bus or hybrid bus, the particle size of particulate matter(PM) less than 2.5μm accounted for more than 98% in the particles emission. It is found that the particles are more likely to deposit to the lung, respiratory bronchioles and alveoli, causing respiratory and lung diseases. Therefore, how to control the PM emissions of hybrid bus is the key factor of the study.

A comparison of machine learning methods for classification using simulation with multiple real data examples from mental health studies.

PubMed

Khondoker, Mizanur; Dobson, Richard; Skirrow, Caroline; Simmons, Andrew; Stahl, Daniel

2016-10-01

Recent literature on the comparison of machine learning methods has raised questions about the neutrality, unbiasedness and utility of many comparative studies. Reporting of results on favourable datasets and sampling error in the estimated performance measures based on single samples are thought to be the major sources of bias in such comparisons. Better performance in one or a few instances does not necessarily imply so on an average or on a population level and simulation studies may be a better alternative for objectively comparing the performances of machine learning algorithms. We compare the classification performance of a number of important and widely used machine learning algorithms, namely the Random Forests (RF), Support Vector Machines (SVM), Linear Discriminant Analysis (LDA) and k-Nearest Neighbour (kNN). Using massively parallel processing on high-performance supercomputers, we compare the generalisation errors at various combinations of levels of several factors: number of features, training sample size, biological variation, experimental variation, effect size, replication and correlation between features. For smaller number of correlated features, number of features not exceeding approximately half the sample size, LDA was found to be the method of choice in terms of average generalisation errors as well as stability (precision) of error estimates. SVM (with RBF kernel) outperforms LDA as well as RF and kNN by a clear margin as the feature set gets larger provided the sample size is not too small (at least 20). The performance of kNN also improves as the number of features grows and outplays that of LDA and RF unless the data variability is too high and/or effect sizes are too small. RF was found to outperform only kNN in some instances where the data are more variable and have smaller effect sizes, in which cases it also provide more stable error estimates than kNN and LDA. Applications to a number of real datasets supported the findings from the simulation study. © The Author(s) 2013.

BOLITA, an Arabidopsis AP2/ERF-like transcription factor that affects cell expansion and proliferation/differentiation pathways.

PubMed

Marsch-Martinez, Nayelli; Greco, Raffaella; Becker, Jörg D; Dixit, Shital; Bergervoet, Jan H W; Karaba, Aarati; de Folter, Stefan; Pereira, Andy

2006-12-01

The BOLITA (BOL) gene, an AP2/ERF transcription factor, was characterized with the help of an activation tag mutant and overexpression lines in Arabidopsis and tobacco. The leaf size of plants overexpressing BOL was smaller than wild type plants due to a reduction in both cell size and cell number. Moreover, severe overexpressors showed ectopic callus formation in roots. Accordingly, global gene expression analysis using the overexpression mutant reflected the alterations in cell proliferation, differentiation and growth through expression changes in RBR, CYCD, and TCP genes, as well as genes involved in cell expansion (i.e. expansins and the actin remodeling factor ADF5). Furthermore, the expression of hormone signaling (i.e. auxin and cytokinin), biosynthesis (i.e. ethylene and jasmonic acid) and regulatory genes was found to be perturbed in bol-D mutant leaves.

Monitoring of peri-distal gastrectomy carbohydrate antigen 19-9 level in gastric juice and its significance

PubMed Central

Xu, A-Man; Huang, Lei; Han, Wen-Xiu; Wei, Zhi-Jian

2014-01-01

Gastric carcinoma is one of the most common and deadly malignancies nowadays, and carbohydrate antigen 19-9 (CA 19-9) in gastric juice has been rarely studied. To compare peri-distal gastrectomy (DG) gastric juice and serum CA 19-9 and reveal its significance, we selected 67 patients diagnosed with gastric carcinoma who underwent DG, and collected their perioperative gastric juice whose CA 19-9 was detected, with serum CA 19-9 monitored as a comparison. We found that: gastric juice CA 19-9 pre-gastrectomy was significantly correlated with tumor TNM classification, regarding tumor size, level of gastric wall invaded, differentiated grade and number of metastatic lymph nodes as influencing factors, while serum CA 19-9 revealed little information; gastric juice CA 19-9 was significantly correlated with radical degree, and regarded number of resected lymph nodes and classification of cutting edge as impact factors; thirteen patients whose gastric juice CA 19-9 rose post-DG showed features indicating poor prognosis; the difference of gastric juice CA 19-9 between pre- and post-gastrectomy was correlated with tumor TNM classification and radical degree, and regarded tumor size, number of resected metastatic and normal lymph nodes, sum of distances from tumor to cutting edges and classification of cutting edge as influential factors. We conclude that peri-DG gastric juice CA 19-9 reveals much information about tumor and radical gastrectomy, and may indicate prognosis; while serum CA 19-9 has limited significance. PMID:24482710

Comparative analysis of cells and proteins of pumpkin plants for the control of fruit size.

PubMed

Nakata, Yumiko; Taniguchi, Go; Takazaki, Shinya; Oda-Ueda, Naoko; Miyahara, Kohji; Ohshima, Yasumi

2012-09-01

Common pumpkin plants (Cucurbita maxima) produce fruits of 1-2 kg size on the average, while special varieties of the same species called Atlantic Giant are known to produce a huge fruit up to several hundred kilograms. As an approach to determine the factors controlling the fruit size in C. maxima, we cultivated both AG and control common plants, and found that both the cell number and cell sizes were increased in a large fruit while DNA content of the cell did not change significantly. We also compared protein patterns in the leaves, stems, ripe and young fruits by two-dimensional (2D) gel electrophoresis, and identified those differentially expressed between them with mass spectroscopy. Based on these results, we suggest that factors in photosynthesis such as ribulose-bisphosphate carboxylase, glycolysis pathway enzymes, heat-shock proteins and ATP synthase play positive or negative roles in the growth of a pumpkin fruit. These results provide a step toward the development of plant biotechnology to control fruit size in the future. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Distribution of transvascular pathway sizes through the pulmonary microvascular barrier.

PubMed

McNamee, J E

1987-01-01

Mathematical models of solute and water exchange in the lung have been helpful in understanding factors governing the volume flow rate and composition of pulmonary lymph. As experimental data and models become more encompassing, parameter identification becomes more difficult. Pore sizes in these models should approach and eventually become equivalent to actual physiological pathway sizes as more complex and accurate models are tried. However, pore sizes and numbers vary from model to model as new pathway sizes are added. This apparent inconsistency of pore sizes can be explained if it is assumed that the pulmonary blood-lymph barrier is widely heteroporous, for example, being composed of a continuous distribution of pathway sizes. The sieving characteristics of the pulmonary barrier are reproduced by a log normal distribution of pathway sizes (log mean = -0.20, log s.d. = 1.05). A log normal distribution of pathways in the microvascular barrier is shown to follow from a rather general assumption about the nature of the pulmonary endothelial junction.

Characteristics of inhalable particulate matter concentration and size distribution from power plants in China.

PubMed

Yi, Honghong; Hao, Jiming; Duan, Lei; Li, Xinghua; Guo, Xingming

2006-09-01

In this investigation, the collection efficiency of particulate emission control devices (PECDs), particulate matter (PM) emissions, and PM size distribution were determined experimentally at the inlet and outlet of PECDs at five coal-fired power plants. Different boilers, coals, and PECDs are used in these power plants. Measurement in situ was performed by an electrical low-pressure impactor with a sampling system, which consisted of an isokinetic sampler probe, precut cyclone, and two-stage dilution system with a sample line to the instruments. The size distribution was measured over a range from 0.03 to 10 microm. Before and after all of the PECDs, the particle number size distributions display a bimodal distribution. The PM2.5 fraction emitted to atmosphere includes a significant amount of the mass from the coarse particle mode. The controlled and uncontrolled emission factors of total PM, inhalable PM (PM10), and fine PM P(M2.5) were obtained. Electrostatic precipitator (ESP) and baghouse total collection efficiencies are 96.38-99.89% and 99.94%, respectively. The minimum collection efficiency of the ESP and the baghouse both appear in the particle size range of 0.1-1 microm. In this size range, ESP and baghouse collection efficiencies are 85.79-98.6% and 99.54%. Real-time measurement shows that the mass and number concentration of PM10 will be greatly affected by the operating conditions of the PECDs. The number of emitted particles increases with increasing boiler load level because of higher combustion temperature. During test run periods, the data reproducibility is satisfactory.

Number comparison and number ordering as predictors of arithmetic performance in adults: Exploring the link between the two skills, and investigating the question of domain-specificity.

PubMed

Morsanyi, Kinga; O'Mahony, Eileen; McCormack, Teresa

2017-12-01

Recent evidence has highlighted the important role that number-ordering skills play in arithmetic abilities, both in children and adults. In the current study, we demonstrated that number comparison and ordering skills were both significantly related to arithmetic performance in adults, and the effect size was greater in the case of ordering skills. Additionally, we found that the effect of number comparison skills on arithmetic performance was mediated by number-ordering skills. Moreover, performance on comparison and ordering tasks involving the months of the year was also strongly correlated with arithmetic skills, and participants displayed similar (canonical or reverse) distance effects on the comparison and ordering tasks involving months as when the tasks included numbers. This suggests that the processes responsible for the link between comparison and ordering skills and arithmetic performance are not specific to the domain of numbers. Finally, a factor analysis indicated that performance on comparison and ordering tasks loaded on a factor that included performance on a number line task and self-reported spatial thinking styles. These results substantially extend previous research on the role of order processing abilities in mental arithmetic.

Factors affecting ground-water exchange and catchment size for Florida lakes in mantled karst terrain

USGS Publications Warehouse

Lee, Terrie Mackin

2002-01-01

In the mantled karst terrain of Florida, the size of the catchment delivering ground-water inflow to lakes is often considerably smaller than the topographically defined drainage basin. The size is determined by a balance of factors that act individually to enhance or diminish the hydraulic connection between the lake and the adjacent surficial aquifer, as well as the hydraulic connection between the surficial aquifer and the deeper limestone aquifer. Factors affecting ground-water exchange and the size of the ground-water catchment for lakes in mantled karst terrain were examined by: (1) reviewing the physical and hydrogeological characteristics of 14 Florida lake basins with available ground-water inflow estimates, and (2) simulating ground-water flow in hypothetical lake basins. Variably-saturated flow modeling was used to simulate a range of physical and hydrogeologic factors observed at the 14 lake basins. These factors included: recharge rate to the surficial aquifer, thickness of the unsaturated zone, size of the topographically defined basin, depth of the lake, thickness of the surficial aquifer, hydraulic conductivity of the geologic units, the location and size of karst subsidence features beneath and onshore of the lake, and the head in the Upper Floridan aquifer. Catchment size and the magnitude of ground-water inflow increased with increases in recharge rate to the surficial aquifer, the size of the topographically defined basin, hydraulic conductivity in the surficial aquifer, the degree of confinement of the deeper Upper Floridan aquifer, and the head in the Upper Floridan aquifer. The catchment size and magnitude of ground-water inflow increased with decreases in the number and size of karst subsidence features in the basin, and the thickness of the unsaturated zone near the lake. Model results, although qualitative, provided insights into: (1) the types of lake basins in mantled karst terrain that have the potential to generate small and large amounts of ground-water inflow, and (2) the location of ground-water catchments that could be managed to safeguard lake water quality. Knowledge of how ground-water catchments are related to lakes could be used by water-resource managers to recommend setback distances for septic tank drain fields, agricultural land uses, and other land-use practices that contribute nutrients and major ions to lakes.

How the Emitted Size Distribution and Mixing State of Feldspar Affect Ice Nucleating Particles in a Global Model

NASA Technical Reports Server (NTRS)

Perlwitz, Jan P.; Fridlind, Ann M.; Knopf, Daniel A.; Miller, Ron L.; García-Pando, Carlos Perez

2017-01-01

The effect of aerosol particles on ice nucleation and, in turn, the formation of ice and mixed phase clouds is recognized as one of the largest sources of uncertainty in climate prediction. We apply an improved dust mineral specific aerosol module in the NASA GISS Earth System ModelE, which takes into account soil aggregates and their fragmentation at emission as well as the emission of large particles. We calculate ice nucleating particle concentrations from K-feldspar abundance for an active site parameterization for a range of activation temperatures and external and internal mixing assumption. We find that the globally averaged INP concentration is reduced by a factor of two to three, compared to a simple assumption on the size distribution of emitted dust minerals. The decrease can amount to a factor of five in some geographical regions. The results vary little between external and internal mixing and different activation temperatures, except for the coldest temperatures. In the sectional size distribution, the size range 24 micrometer contributes the largest INP number.

How the Emitted Size Distribution and Mixing State of Feldspar Affect Ice Nucleating Particles in a Global Model

NASA Astrophysics Data System (ADS)

Perlwitz, J. P.; Fridlind, A. M.; Knopf, D. A.; Miller, R. L.; Pérez García-Pando, C.

2017-12-01

The effect of aerosol particles on ice nucleation and, in turn, the formation of ice and mixed phase clouds is recognized as one of the largest sources of uncertainty in climate prediction. We apply an improved dust mineral specific aerosol module in the NASA GISS Earth System ModelE, which takes into account soil aggregates and their fragmentation at emission as well as the emission of large particles. We calculate ice nucleating particle concentrations from K-feldspar abundance for an active site parameterization for a range of activation temperatures and external and internal mixing assumption. We find that the globally averaged INP concentration is reduced by a factor of two to three, compared to a simple assumption on the size distribution of emitted dust minerals. The decrease can amount to a factor of five in some geographical regions. The results vary little between external and internal mixing and different activation temperatures, except for the coldest temperatures. In the sectional size distribution, the size range 2-4 μm contributes the largest INP number.

Guatemalan women achieve ideal family size: Empowerment through education and decision-making.

PubMed

Poelker, Katelyn E; Gibbons, Judith L

2018-02-01

Women's empowerment in family planning strengthens families and communities. Using 2014/2015 Demographic and Health Surveys data from 7,168 Guatemalan women, ages 35 and above with at least one living child, we examined indicators of empowerment in four domains - economic, educational, social, and contraceptive - and their relation to the number of living children compared to the ideal number of children. We reveal our analysis showing that economic, educational, and social empowerment predicted achieving the preferred number of children. Education and control over their own income are two critical empowerment factors for Guatemalan women.

Time trends and determinants of completed family size in a rural community from the Basque area of Spain (1800-1969).

PubMed

Alfonso-Sánchez, Miguel A; Peña, José A; Calderón, Rosario

2003-10-01

The focus of this work is the analysis of changes in completed family size and possible determinants of that size over time, in an attempt to characterize the evolution of reproductive patterns during the demographic transition. With this purpose in mind, time trends are studied in relation to the mean number of live births per family (as an indirect measure of fertility), using family reconstitution techniques to trace the reproductive history of each married woman. The population surveyed is a Spanish rural community called Lanciego, located at the southern end of the province of Alava (Basque Country). A total of 24,510 parish records of baptisms, marriages and burials made between 1800 and 1969 were examined to obtain the demographic data set. For each reconstituted family, the variables included in the study were the number of live births per family or family size (FAMS), year of marriage (YEAR), age at marriage of both partners (AMAN, AWOM), wife's age at the end of marriage (WEND), duration of marriage (MARD), age at first maternity (A1CH), length of reproductive span (REPS) and number of children dying before their first anniversary (MINF). Through a principal component analysis, three factors were found that explained more than 75% of the total variance. Association of variables in factors I and III was particularly useful in characterizing the variability of mean family size in pre-transitional, transitional and post-transitional cohorts. During demographic transition, a decreasing trend is observed in the variables FAMS, REPS and MINF, while variables AWOM, AMAN, WEND and A1CH show a tendency to increase over the 20th century. Results obtained by multiple regression analysis confirm that the best predictors of family size (dependent variable) were REPS and MINF, which between them explained over 85% of the total variation in FAMS (R2 = 0.853). In Lanciego, birth control seems to be present on the evidence of an increase in age at first maternity and a decrease in age at last parturition, indicating that the beginning of the reproductive span is delayed and its end is brought forward. Interaction between family size and infant mortality is discussed in the light of various hypotheses, including replacement of descendants, the so-called biological effect and the theory of r and k selection.

Analysis of factors influencing safety management for metro construction in China.

PubMed

Yu, Q Z; Ding, L Y; Zhou, C; Luo, H B

2014-07-01

With the rapid development of urbanization in China, the number and size of metro construction projects are increasing quickly. At the same time, and increasing number of accidents in metro construction make it a disturbing focus of social attention. In order to improve safety management in metro construction, an investigation of the participants' perspectives on safety factors in China metro construction has been conducted to identify the key safety factors, and their ranking consistency among the main participants, including clients, consultants, designers, contractors and supervisors. The result of factor analysis indicates that there are five key factors which influence the safety of metro construction including safety attitude, construction site safety, government supervision, market restrictions and task unpredictability. In addition, ANOVA and Spearman rank correlation coefficients were performed to test the consistency of the means rating and the ranking of safety factors. The results indicated that the main participants have significant disagreement about the importance of safety factors on more than half of the items. Suggestions and recommendations on practical countermeasures to improve metro construction safety management in China are proposed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Space Biology and Aerospace Medicine, Number 5, 1977.

DTIC Science & Technology

1977-11-10

Severity of Caloric Nystagmus (V. N. Krut’ko, et al.)..,»,..,.. 94 A Study of the Pulsed Method of Laundering (B. A, Adamovich, et al,)’ .... 100...diminished motor activity. As we know, hypo - kinesia is very important as an etiological factor in onset of a number of diseases, mainly referable to...artificial gravitation; they were 8x8x28 cm in size and we put 5 mice in each. The animals were on a mixed diet , and they were fed both during

Genetics of renal hypoplasia: insights into the mechanisms controlling nephron endowment.

PubMed

Cain, Jason E; Di Giovanni, Valeria; Smeeton, Joanna; Rosenblum, Norman D

2010-08-01

Renal hypoplasia, defined as abnormally small kidneys with normal morphology and reduced nephron number, is a common cause of pediatric renal failure and adult-onset disease. Genetic studies performed in humans and mutant mice have implicated a number of critical genes, in utero environmental factors and molecular mechanisms that regulate nephron endowment and kidney size. Here, we review current knowledge regarding the genetic contributions to renal hypoplasia with particular emphasis on the mechanisms that control nephron endowment in humans and mice.

A nationwide survey of factors influencing adherence to ocular hypotensive eyedrops in Japan.

PubMed

Tsumura, Toyoaki; Kashiwagi, Kenji; Suzuki, Yasuyuki; Yoshikawa, Keiji; Suzumura, Hirotaka; Maeda, Toshine; Takeda, Ryuji; Saito, Hitomi; Araie, Makoto

2018-01-12

Few reports have investigated the status of adherence in Japan on a large scale. We aimed to investigate the status of adherence to topical glaucoma treatment and its associated factors. A nationwide survey was conducted as a prospective fashion. Participants in this survey were subjects with primary open-angle glaucoma, normal-tension glaucoma, or ocular hypertension or pseudoexfoliation glaucoma who had been prescribed anti-glaucoma ophthalmic eyedrops and whose ophthalmologist considered prescribing any fixed combination of ocular hypotensive eyedrops for the first time between 2011 and 2012. Subjects and their attending ophthalmologists independently completed a questionnaire by utilizing a fixed combination of ocular hypotensive eyedrops. A total of 1358 ophthalmologists from 1071 medical institutions participated in this survey. We registered 4430 subjects (2049 males and 2381 females). In total, data from 3853 subjects (87.6%) were analyzed after inclusion of subjects based on inclusion and exclusion criteria. Good adherence was defined as not forgetting instillation during the past week. Rates of good adherence reported by subjects and ophthalmologists were 72.4 and 78.5%, respectively (P < 0.0001). The consistency of adherence evaluation between subjects and ophthalmologists was moderate [kappa score 0.5025 (95% confidence interval 0.4740-0.5309)]. Significant factors associated with adherence were size of clinic, age, gender, number of types of ocular hypotensive eyedrops, ease of instillation, preferred number of eyedrops, preferred frequency of instillation of eyedrops, and knowledge of glaucoma. Adherence to ocular hypotensive eyedrops among Japanese subjects was relatively good. Concordance of adherence between subjects' reports and ophthalmologists' responses was moderate. Size of clinic, number of types of ocular hypotensive eyedrops, ease of instillation, preferred number of eyedrops, preferred frequency of instillation of eyedrops, and knowledge of glaucoma were associated with adherence among Japanese glaucoma subjects.

Stimulating Positive Emotional Experiences in Mathematics Learning: Influence of Situational and Personal Factors

ERIC Educational Resources Information Center

Winberg, T. Mikael; Hellgren, Jenny M.; Palm, Torulf

2014-01-01

The study aims to assess the relative importance of a large number of variables for predicting students' positive-activating emotions during mathematics learning. Participants were 668 first-year upper secondary school students from 33 schools of different sizes and locations. Two questionnaires were distributed, one assessing students'…

The Elusive Cost of Library Software

ERIC Educational Resources Information Center

Breeding, Marshall

2009-01-01

Software pricing is not a straightforward issue, since each procurement involves a special business arrangement between a library and its chosen vendor. The author thinks that it is reasonable to scale the cost of a product to such factors as the size of the library, the complexity of the installation, the number of simultaneous users, or the…

Assessing forest fragmentation metrics from forest inventory cluster samples

Treesearch

Christoph Kleinn

2000-01-01

Fragmentation of forest area plays an important role in the ongoing discussion of forest dynamics and biological and ecosystem diversity. Among its contributing factors are size, shape, number, and spatial arrangement of forest patches. Several metrics and indexes are in use, predominantly in quantitative landscape ecology. An important area of interest is the...

An Analysis of Fifth-Grade Students' Performance When Solving Selected Open Distributive Sentences. Technical Report No. 397.

ERIC Educational Resources Information Center

Hobbs, Charles Eugene

The author investigates elementary school students' performance when solving selected open distributive sentences in relation to three factors (Open Sentence Type, Context, Number Size) and identifies and classifies solution methods attempted by students and students' errors in performance. Eighty fifth-grade students participated in the…

Chapter 1: Overview of the integrated landscape assessment project

Treesearch

Miles A. Hemstrom; Jessica E. Halofsky; F. Jack Triepke; R. James Barbour; Janine Salwasser

2014-01-01

Fire suppression, vegetation management activities, wildfires, grazing, climate change, and other factors result in constantly changing vegetation and habitat conditions across millions of hectares in the Western United States. In recent years, the size and number of large wildfires has grown, threatening lives, property, and ecosystem integrity. At the same time,...

An Investigation of the Sampling Distribution of the Congruence Coefficient.

ERIC Educational Resources Information Center

Broadbooks, Wendy J.; Elmore, Patricia B.

This study developed and investigated an empirical sampling distribution of the congruence coefficient. The effects of sample size, number of variables, and population value of the congruence coefficient on the sampling distribution of the congruence coefficient were examined. Sample data were generated on the basis of the common factor model and…

Lymph node size as a simple prognostic factor in node negative colon cancer and an alternative thesis to stage migration.

PubMed

Märkl, Bruno; Schaller, Tina; Kokot, Yuriy; Endhardt, Katharina; Kretsinger, Hallie; Hirschbühl, Klaus; Aumann, Georg; Schenkirsch, Gerhard

2016-10-01

Stage migration is an accepted explanation for the association between lymph node (LN) yield and outcome in colon cancer. To investigate whether the alternative thesis of immune response is more likely, we performed a retrospective study. We enrolled 239 cases of node negative cancers, which were categorized according to the number of LNs with diameters larger than 5 mm (LN5) into the groups LN5-very low (0 to 1 LN5), LN5-low (2 to 5 LN5), and LN5-high (≥6 LN5). Significant differences were found in pT3/4 cancers with median survival times of 40, 57, and 71 months (P = .022) in the LN5-very low, LN5-low, and LN5-high groups, respectively. Multivariable analysis revealed that LN5 number and infiltration type were independent prognostic factors. LN size is prognostic in node negative colon cancer. The correct explanation for outcome differences associated with LN harvest is probably the activation status of LNs. Copyright © 2015 Elsevier Inc. All rights reserved.

Characteristics of German hospitals adopting health IT systems - results from an empirical study.

PubMed

Liebe, Jan-David; Egbert, Nicole; Frey, Andreas; Hübner, Ursula

2011-01-01

Hospital characteristics that facilitate IT adoption have been described by the literature extensively, however with controversial results. The aim of this study therefore is to draw a set of the most important variables from previous studies and include them in a combined analysis for testing their contribution as single factors and their interactions. Total number of IT systems installed and number of clinical IT systems in the hospital were used as criterion variables. Data from a national survey of German hospitals served as basis. Based on a stepwise multiple regression analysis four variables were identified to significantly explain the degree of IT adoption (60% explained variance): 1) hospital size, 2) IT department, 3) reference customer and 4) ownership (private vs. public). Our results replicate previous findings with regard to hospital size and ownership. In addition our study emphasizes the importance of a reliable internal structure for IT projects (existence of an IT department) and the culture of testing and installing most recent IT products (being a reference customer). None of the interactions between factors was significant.

The use of Design of Experiments and Response Surface Methodology to optimize biomass and lipid production by the oleaginous marine green alga, Nannochloropsis gaditana in response to light intensity, inoculum size and CO2.

PubMed

Hallenbeck, Patrick C; Grogger, Melanie; Mraz, Megan; Veverka, Donald

2015-05-01

Biodiesel produced from microalgal lipids is being considered as a potential source of renewable energy. However, a number of hurdles will have to be overcome if such a process is to become practical. One important factor is the volumetric production of biomass and lipid that can be achieved. The marine alga Nannochloropsis gaditana is under study since it is known to be highly oleaginous and has a number of other attractive properties. Factors that might be important in biomass and lipid production by this alga are light intensity, inoculum size and CO2. Here we have carried out for the first time a RSM-DOE study of the influence of these important culture variables and define conditions that maximize biomass production, lipid content (BODIPY® fluorescence) and total lipid production. Moreover, flow cytometry allowed the examination on a cellular level of changes that occur in cellular populations as they age and accumulate lipids. Copyright © 2014 Elsevier Ltd. All rights reserved.

Constraining response output on conjunctive fixed-ratio 1 fixed-time reinforcement schedules: Effects on the postreinforcement pause.

PubMed

Lopez, F; Pereira, C

1985-03-01

Two experiments used response-restriction procedures in order to test the independence of the factors determining response rate and the factors determining the size of the postreinforcement pause on interval schedules. Responding was restricted by response-produced blackout or by retracting the lever. In Experiment 1 with a Conjunctive FR 1 FT schedule, the blackout procedure reduced the postreinforcement pause more than the lever-retraction procedure did, and both procedures produced shorter pauses than did the schedule without response restriction. In Experiment 2 the interreinforcement interval was also manipulated, and the size of the pause was an increasing function of the interreinforcement interval, but the rate of increase was lower than that produced by fixed interval schedules of comparable interval durations. The assumption of functional independence of the postreinforcement pause and terminal rate in fixed interval schedules is questioned since data suggest that pause reductions resulted from constraining variation in response number compared to equivalent periodic schedules in which response number was allowed to vary. Copyright © 1985. Published by Elsevier B.V.

Production, perceptions, and punishment: restrictive deterrence in the context of cannabis cultivation.

PubMed

Nguyen, Holly; Malm, Aili; Bouchard, Martin

2015-03-01

American authorities have invested extraordinary resources to keep up with the growth in cannabis cultivation, and state-level cannabis laws have been changing rapidly. Despite these changes, little research on the relationship between criminal justice sanctions and grower behaviours exist, in particular research that examines restrictive deterrence - the altering of an illegal behaviour as opposed to desisting from it completely. We examine restrictive deterrence in the context of cannabis cultivation by modelling the relationship between the threat of sanctions and the size of cultivation site and number of co-offenders. We use data from an anonymous web survey where participants were recruited through advertisements on websites related to cannabis use and cultivation. Negative binomial regression were used on 337 cases that contain valid data on size of cultivation site and 338 cases that contain valid data on the number of co-offenders. Our study found some evidence that the severity of state sanctions reduces the size of cultivation sites among growers who reside in the state. However, the number of contacts with the police had the opposite effect. In addition, we did not find a restrictive deterrent effect for the number of co-offenders, suggesting that different factors affect different decision points. Interestingly, objective skill and subjective skill had positive and independent effects on size of site. Results suggest that state-level sanctions have a structuring effect by restricting the size of cultivation sites but further increases in sanctions or enforcement are unlikely to deter more individuals from growing cannabis. In fact, there may be some potential dangers of increased enforcement on cannabis growers. Copyright © 2014 Elsevier B.V. All rights reserved.

3D Thermal and Electrochemical Model for Spirally Wound Large Format Lithium-ion Batteries (Presentation)

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

Lee, K. J.; Kim, G. H.; Smith, K.

In many commercial cells, long tabs at both cell sides, leading to uniform potentials along the spiral direction of wound jelly rolls, are rarely seen because of their high manufacturing cost. More often, several metal strips are welded at discrete locations along both current collector foils. With this design, the difference of electrical potentials is easily built up along current collectors in the spiral direction. Hence, the design features of the tabs, such as number, location and size, can be crucial factors for spiral-shaped battery cells. This paper presents a Li-ion battery cell model having a 3-dimensional spiral mesh involvingmore » a wound jellyroll structure. Further results and analysis will be given regarding impacts of tab location, number, and size.« less

Prototype solar heating and hot water systems

NASA Technical Reports Server (NTRS)

1977-01-01

Alternative approaches to solar heating and hot water system configurations were studied, parametrizing the number and location of the dampers, the number and location of the fans, the interface locations with the furnace, the size and type of subsystems, and operating modes. A two-pass air-heating collector was selected based on efficiency and ease of installation. Also, an energy transport module was designed to compactly contain all the mechanical and electrical control components. System performance calculations were carried out over a heating season for the tentative site location at Tunkhnana, Pa. Results illustrate the effect of collector size, storage capacity, and use of a reflector. Factors which affected system performance include site location, insulative quality of the house, and of the system components. A preliminary system performance specification is given.

Some applications of the Kronecker product in Hubbard representation

NASA Astrophysics Data System (ADS)

Enríquez, Marco; Rosas-Ortiz, Oscar

2014-10-01

The properties of the Kronecker product are revisited in terms of Hubbard operators. The simplest representation of a Hubbard operator Xi,jn is a square matrix of size n with an entry equal to 1 and zero elsewhere. This framework simplifies the calculation of the Kronecker product of arbitrary matrices no matter the size or the number of the involved factors. Some applications are presented, these include the algebra of permutation matrices, the Hadamard matrix, the XXX Heisenberg model and the interaction of an atom with radiation fields.

Shorter unentangled proofs for ground state connectivity

NASA Astrophysics Data System (ADS)

Caha, Libor; Nagaj, Daniel; Schwarz, Martin

2018-07-01

Can one considerably shorten a proof for a quantum problem by using a protocol with a constant number of unentangled provers? We consider a frustration-free variant of the sf {QCMA}-complete ground state connectivity (GSCON) problem for a system of size n with a proof of superlinear size. We show that we can shorten this proof in sf {QMA}(2): There exists a two-copy, unentangled proof with length of order n, up to logarithmic factors, while the completeness-soundness gap of the new protocol becomes a small inverse polynomial in n.

Reproductive ecology of Emperor Geese: Survival of adult females

USGS Publications Warehouse

Petersen, Margaret R.

1992-01-01

Life history theory predicts a decrease in survival with increased reproductive effort of individuals. This relationship, however, is highly variable among and within species. I studied the nesting success and survival of adult female Emperor Geese during 1982-1986 and found no direct evidence that differential reproductive effort as measured by the number of eggs laid or hatching success had a significant negative effect on survival to the next breeding season. Incubated clutch size, hatched clutch size, number of parasitic eggs, nest initiation date, hatch date, and mass at hatch were not related to subsequent survival. Of the factors I examined, only an attempt to nest the previous season was related to survival of a female. I suggest that the higher probability of survival among non-nesting adult female Emperor Geese was primarily related to hunting pressure on the nesting area between spring and fall migration. The probability of survival was increased for females with larger clutches, suggesting a positive relationship between brood size and survival.

Modeling annual mallard production in the prairie-parkland region

USGS Publications Warehouse

Miller, M.W.

2000-01-01

Biologists have proposed several environmental factors that might influence production of mallards (Anas platyrhynchos) nesting in the prairie-parkland region of the United States and Canada. These factors include precipitation, cold spring temperatures, wetland abundance, and upland breeding habitat. I used long-term historical data sets of climate, wetland numbers, agricultural land use, and size of breeding mallard populations in multiple regression analyses to model annual indices of mallard production. Models were constructed at 2 scales: a continental scale that encompassed most of the mid-continental breeding range of mallards and a stratum-level scale that included 23 portions of that same breeding range. The production index at the continental scale was the estimated age ratio of mid-continental mallards in early fall; at the stratum scale my production index was the estimated number of broods of all duck species within an aerial survey stratum. Size of breeding mallard populations in May, and pond numbers in May and July, best modeled production at the continental scale. Variables that best modeled production at the stratum scale differed by region. Crop variables tended to appear more in models for western Canadian strata; pond variables predominated in models for United States strata; and spring temperature and pond variables dominated models for eastern Canadian strata. An index of cold spring temperatures appeared in 4 of 6 models for aspen parkland strata, and in only 1 of 11 models for strata dominated by prairie. Stratum-level models suggest that regional factors influencing mallard production are not evident at a larger scale. Testing these potential factors in a manipulative fashion would improve our understanding of mallard population dynamics, improving our ability to manage the mid-continental mallard population.

Neoadjuvant conformal chemoradiation with induction chemotherapy for rectal adenocarcinoma. A prospective observational study.

PubMed

Fekete, Zsolt; Muntean, Alina-Simona; Hica, Ştefan; Rancea, Alin; Resiga, Liliana; Csutak, Csaba; Todor, Nicolae; Nagy, Viorica Magdalena

2014-06-01

The purpose of this prospective observational study was to evaluate the rate and the prognostic factors for down-staging and complete response for rectal adenocarcinoma after induction chemotherapy and neoadjuvant chemoradiation followed by surgery, and to analyze the rate of sphincter-saving surgery. We included from March 2011 to October 2013 a number of 88 patients hospitalized with locally advanced rectal adenocarcinoma in the Prof. Dr. Ion Chiricuta Institute of Oncology, Cluj. The treatment schedule included 2-4 cycles of Oxaliplatin plus a fluoropyrimidine followed by concomitant chemoradiation with a dose of 50 Gy in 25 fractions combined with a fluoropyrimidine monotherapy. The rate of T down-staging was 49.4% (40/81 evaluable patients). Independent prognostic factors for T down-staging were: age >57 years (p<0.01), cN0 (p<0.01), distance from anal verge >5 cm (p<0.01), initial CEA <6.2 ng/ml (p<0.01), higher number of chemotherapy cycles with Oxaliplatin (pROC=0.05) and protraction of radiotherapy of >35 days (p<0.01). Nine patients from 81 (11.1%) presented complete response (7 pathological and 2 clinical); the independent prognostic factors were stage cT2 versus cT3-4 (p<0.01), initial tumor size ≤3.5 cm and distance from anal verge >5 cm (p=0.03). Sixty-eight patients (79.1%) underwent radical surgery and among them 35 patients (51.5 %) had a sphincter saving procedure. Induction chemotherapy with neoadjuvant chemoradiation produced important down-staging in rectal adenocarcinoma. Independent prognostic factors for T down-staging were: age, cN0, distance from anal verge, initial CEA, the number of Oxaliplatin cycles and duration of radiotherapy; for complete response: cT2, initial tumor size and distance from the anal verge.

Mapping the Solar System with LSST

NASA Astrophysics Data System (ADS)

Ivezic, Z.; Juric, M.; Lupton, R.; Connolly, A.; Kubica, J.; Moore, A.; Harris, A.; Bowell, T.; Bernstein, G.; Stubbs, C.; LSST Collaboration

2004-12-01

The currently considered LSST cadence, based on two 10 sec exposures, may result in orbital parameters, light curves and accurate colors for over a million main-belt asteroids (MBA), and about 20,000 trans-Neptunian objects (TNO). Compared to the current state-of-the-art, this sample would represent a factor of 5 increase in the number of MBAs with known orbits, a factor of 20 increase in the number of MBAs with known orbits and accurate color measurements, and a factor of 100 increase in the number of MBAs with measured variability properties. The corresponding sample increase for TNOs is 10, 100, and 1000, respectively. The LSST MBA and TNO samples will enable detailed studies of the dynamical and chemical history of the solar system. For example, they will constrain the MBA size distribution for objects larger than 100 m, and TNO size distribution for objects larger than 100 km, their physical state through variability measurements (solid body vs. a rubble pile), as well as their surface chemistry through color measurements. A proposed deep TNO survey, based on 1 hour exposures, may result in a sample of about 100,000 TNOs, while spending only 10% of the LSST observing time. Such a deep TNO survey would be capable of discovering Sedna-like objects at distances beyond 150 AU, thereby increasing the observable Solar System volume by about a factor of 7. The increase in data volume associated with LSST asteroid science will present many computational challenges to how we might extract tracks and orbits of asteroids from the underlying clutter. Tree-based algorithms for multihypothesis testing of asteroid tracks can help solve these challenges by providing the necessary 1000-fold speed-ups over current approaches while recovering 95% of the underlying asteroid populations.

Classification of Earthquake-triggered Landslide Events - Review of Classical and Particular Cases

NASA Astrophysics Data System (ADS)

Braun, A.; Havenith, H. B.; Schlögel, R.

2016-12-01

Seismically induced landslides often contribute to a significant degree to the losses related to earthquakes. The identification of possible extends of landslide affected areas can help to target emergency measures when an earthquake occurs or improve the resilience of inhabited areas and critical infrastructure in zones of high seismic hazard. Moreover, landslide event sizes are an important proxy for the estimation of the intensity and magnitude of past earthquakes in paleoseismic studies, allowing us to improve seismic hazard assessment over longer terms. Not only earthquake intensity, but also factors such as the fault characteristics, topography, climatic conditions and the geological environment have a major impact on the intensity and spatial distribution of earthquake induced landslides. Inspired by classical reviews of earthquake induced landslides, e.g. by Keefer or Jibson, we present here a review of factors contributing to earthquake triggered slope failures based on an `event-by-event' classification approach. The objective of this analysis is to enable the short-term prediction of earthquake triggered landslide event sizes in terms of numbers and size of the affected area right after an earthquake event occurred. Five main factors, `Intensity', `Fault', `Topographic energy', `Climatic conditions' and `Surface geology' were used to establish a relationship to the number and spatial extend of landslides triggered by an earthquake. Based on well-documented recent earthquakes (e.g. Haiti 2010, Wenchuan 2008) and on older events for which reliable extensive information was available (e.g. Northridge 1994, Loma Prieta 1989, Guatemala 1976, Peru 1970) the combination and relative weight of the factors was calibrated. The calibrated factor combination was then applied to more than 20 earthquake events for which landslide distribution characteristics could be crosschecked. We present cases where our prediction model performs well and discuss particular cases where it does not. These are e.g. cases of far distant, delayed or ancient earthquake induced landslides.

Proposal of a new staging system for intrahepatic cholangiocarcinoma: Analysis of surgical patients from a nationwide survey of the Liver Cancer Study Group of Japan.

PubMed

Sakamoto, Yoshihiro; Kokudo, Norihiro; Matsuyama, Yutaka; Sakamoto, Michiie; Izumi, Namiki; Kadoya, Masumi; Kaneko, Shuichi; Ku, Yonson; Kudo, Masatoshi; Takayama, Tadatoshi; Nakashima, Osamu

2016-01-01

In the current American Joint Committee on Cancer/International Union Against Cancer staging system (seventh edition) for intrahepatic cholangiocarcinoma (ICC), tumor size was excluded, and periductal invasion was added as a new tumor classification-defining factor. The objective of the current report was to propose a new staging system for ICC that would be better for stratifying the survival of patients based on data from the nationwide Liver Cancer Study Group of Japan database. Of 756 patients who underwent surgical resection for ICC between 2000 and 2005, multivariate analyses of the clinicopathologic factors of 419 patients who had complete data sets were performed to elucidate relevant factors for inclusion in a new tumor classification and staging system. Overall survival data were best stratified using a cutoff value of 2 cm using a minimal P value approach to discriminate patient survival. The 5-year survival rate of 15 patients who had ICC measuring ≤ 2 cm in greatest dimension without lymph node metastasis or vascular invasion was 100%, and this cohort was defined as T1. Multivariate analysis of prognostic factors for 267 patients with lymph node-negative and metastasis-negative (N0M0) disease indicated that the number of tumors, the presence arterial invasion, and the presence major biliary invasion were independent and significant prognostic factors. The proposed new system, which included tumor number, tumor size, arterial invasion, and major biliary invasion for tumor classification, provided good stratification of overall patient survival according to disease stage. Macroscopic periductal invasion was associated with major biliary invasion and an inferior prognosis. The proposed new staging system, which includes a tumor cutoff size of 2 cm and major biliary invasion, may be useful for assigning patients to surgery. © 2015 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

Brassinosteroid Regulates Seed Size and Shape in Arabidopsis1[W][OPEN

PubMed Central

Jiang, Wen-Bo; Huang, Hui-Ya; Hu, Yu-Wei; Zhu, Sheng-Wei; Wang, Zhi-Yong; Lin, Wen-Hui

2013-01-01

Seed development is important for agriculture productivity. We demonstrate that brassinosteroid (BR) plays crucial roles in determining the size, mass, and shape of Arabidopsis (Arabidopsis thaliana) seeds. The seeds of the BR-deficient mutant de-etiolated2 (det2) are smaller and less elongated than those of wild-type plants due to a decreased seed cavity, reduced endosperm volume, and integument cell length. The det2 mutant also showed delay in embryo development, with reduction in both the size and number of embryo cells. Pollination of det2 flowers with wild-type pollen yielded seeds of normal size but still shortened shape, indicating that the BR produced by the zygotic embryo and endosperm is sufficient for increasing seed volume but not for seed elongation, which apparently requires BR produced from maternal tissues. BR activates expression of SHORT HYPOCOTYL UNDER BLUE1, MINISEED3, and HAIKU2, which are known positive regulators of seed size, but represses APETALA2 and AUXIN RESPONSE FACTOR2, which are negative regulators of seed size. These genes are bound in vivo by the BR-activated transcription factor BRASSINAZOLE-RESISTANT1 (BZR1), and they are known to influence specific processes of integument, endosperm, and embryo development. Our results demonstrate that BR regulates seed size and seed shape by transcriptionally modulating specific seed developmental pathways. PMID:23771896

Evaluation of the distribution and impacts of parasites, pathogens, and pesticides on honey bee (Apis mellifera) populations in East Africa.

PubMed

Muli, Elliud; Patch, Harland; Frazier, Maryann; Frazier, James; Torto, Baldwyn; Baumgarten, Tracey; Kilonzo, Joseph; Kimani, James Ng'ang'a; Mumoki, Fiona; Masiga, Daniel; Tumlinson, James; Grozinger, Christina

2014-01-01

In East Africa, honey bees (Apis mellifera) provide critical pollination services and income for small-holder farmers and rural families. While honey bee populations in North America and Europe are in decline, little is known about the status of honey bee populations in Africa. We initiated a nationwide survey encompassing 24 locations across Kenya in 2010 to evaluate the numbers and sizes of honey bee colonies, assess the presence of parasites (Varroa mites and Nosema microsporidia) and viruses, identify and quantify pesticide contaminants in hives, and assay for levels of hygienic behavior. Varroa mites were present throughout Kenya, except in the remote north. Levels of Varroa were positively correlated with elevation, suggesting that environmental factors may play a role in honey bee host-parasite interactions. Levels of Varroa were negatively correlated with levels of hygienic behavior: however, while Varroa infestation dramatically reduces honey bee colony survival in the US and Europe, in Kenya Varroa presence alone does not appear to impact colony size. Nosema apis was found at three sites along the coast and one interior site. Only a small number of pesticides at low concentrations were found. Of the seven common US/European honey bee viruses, only three were identified but, like Varroa, were absent from northern Kenya. The number of viruses present was positively correlated with Varroa levels, but was not correlated with colony size or hygienic behavior. Our results suggest that Varroa, the three viruses, and Nosema have been relatively recently introduced into Kenya, but these factors do not yet appear to be impacting Kenyan bee populations. Thus chemical control for Varroa and Nosema are not necessary for Kenyan bees at this time. This study provides baseline data for future analyses of the possible mechanisms underlying resistance to and the long-term impacts of these factors on African bee populations.

Evaluation of the Distribution and Impacts of Parasites, Pathogens, and Pesticides on Honey Bee (Apis mellifera) Populations in East Africa

PubMed Central

Frazier, James; Torto, Baldwyn; Baumgarten, Tracey; Kilonzo, Joseph; Kimani, James Ng'ang'a; Mumoki, Fiona; Masiga, Daniel; Tumlinson, James; Grozinger, Christina

2014-01-01

In East Africa, honey bees (Apis mellifera) provide critical pollination services and income for small-holder farmers and rural families. While honey bee populations in North America and Europe are in decline, little is known about the status of honey bee populations in Africa. We initiated a nationwide survey encompassing 24 locations across Kenya in 2010 to evaluate the numbers and sizes of honey bee colonies, assess the presence of parasites (Varroa mites and Nosema microsporidia) and viruses, identify and quantify pesticide contaminants in hives, and assay for levels of hygienic behavior. Varroa mites were present throughout Kenya, except in the remote north. Levels of Varroa were positively correlated with elevation, suggesting that environmental factors may play a role in honey bee host-parasite interactions. Levels of Varroa were negatively correlated with levels of hygienic behavior: however, while Varroa infestation dramatically reduces honey bee colony survival in the US and Europe, in Kenya Varroa presence alone does not appear to impact colony size. Nosema apis was found at three sites along the coast and one interior site. Only a small number of pesticides at low concentrations were found. Of the seven common US/European honey bee viruses, only three were identified but, like Varroa, were absent from northern Kenya. The number of viruses present was positively correlated with Varroa levels, but was not correlated with colony size or hygienic behavior. Our results suggest that Varroa, the three viruses, and Nosema have been relatively recently introduced into Kenya, but these factors do not yet appear to be impacting Kenyan bee populations. Thus chemical control for Varroa and Nosema are not necessary for Kenyan bees at this time. This study provides baseline data for future analyses of the possible mechanisms underlying resistance to and the long-term impacts of these factors on African bee populations. PMID:24740399

Evaluation of risk factors for the recurrence of colorectal polyps and colorectal cancer

PubMed

Ateş, Öztürk; Sivri, Bülent; Kılıçkap, Saadettin

2017-11-13

Background/aim: Colorectal adenomatous polyps are precursors of colorectal cancer (CRC), which can be prevented with surveillance colonoscopy. This study aimed to assess risk factors for the recurrence of colorectal polyps and CRC following polypectomy. Materials and methods: In this single-center trial, a total of 510 patients who applied to the endoscopy unit of Hacettepe University Hospital for various reasons and who were diagnosed with at least one colorectal adenomatous polyp between 2000 and 2010 were retrospectively analyzed. Patients with colorectal adenomatous polyps or CRC recurrences were examined in terms of clinical and histological risk factors. Results: A total of 190 (37.1%) patients had surveillance colonoscopy. Among them, 127 (66.3%) were found to have polyp recurrence. Of the parameters defined for polyp recurrence, no association was found between the number of polyps (1-2, ≥3) (1-3, ≥4) in the first colonoscopy and diabetes mellitus, hypertension, hyperlipidemia, sex, family history of colon malignancy, smoking, alcohol usage, size of polyp (<10 mm, ≥10 mm), or advanced histologic type of polyp. The only significant difference was observed in patients who had left-sided colon polyps. In the basal colonoscopy, 130 patients had been diagnosed with CRC, and a significant correlation was found between the number of polyps (1, ≥2) and polyp size (≥10 mm), anemia, high sedimentation rate (>25), and CRC. In the first surveillance colonoscopy, CRC was detected in 12 patients. There was a significant correlation between the development of CRC and advanced histological type, anemia with high erythrocyte sedimentation rate, polyp size (<10 mm, ≥10 mm), and the number of polyps (<3, ≥3). Conclusion: Patients with left-sided colon polyps had a high risk of developing colorectal polyp recurrence. Moreover, the risk of developing CRC increased in patients who had advanced histology, a polyp larger than 10 mm, or more than three polyps.

A Two-Tier Golgi-Based Control of Organelle Size Underpins the Functional Plasticity of Endothelial Cells

PubMed Central

Ferraro, Francesco; Kriston-Vizi, Janos; Metcalf, Daniel J.; Martin-Martin, Belen; Freeman, Jamie; Burden, Jemima J.; Westmoreland, David; Dyer, Clare E.; Knight, Alex E.; Ketteler, Robin; Cutler, Daniel F.

2014-01-01

Summary Weibel-Palade bodies (WPBs), endothelial-specific secretory granules that are central to primary hemostasis and inflammation, occur in dimensions ranging between 0.5 and 5 μm. How their size is determined and whether it has a functional relevance are at present unknown. Here, we provide evidence for a dual role of the Golgi apparatus in controlling the size of these secretory carriers. At the ministack level, cisternae constrain the size of nanostructures (“quanta”) of von Willebrand factor (vWF), the main WPB cargo. The ribbon architecture of the Golgi then allows copackaging of a variable number of vWF quanta within the continuous lumen of the trans-Golgi network, thereby generating organelles of different sizes. Reducing the WPB size abates endothelial cell hemostatic function by drastically diminishing platelet recruitment, but, strikingly, the inflammatory response (the endothelial capacity to engage leukocytes) is unaltered. Size can thus confer functional plasticity to an organelle by differentially affecting its activities. PMID:24794632

Risk factors for baclofen pump infection in children: a multivariate analysis.

PubMed

Spader, Heather S; Bollo, Robert J; Bowers, Christian A; Riva-Cambrin, Jay

2016-06-01

OBJECTIVE Intrathecal baclofen infusion systems to manage severe spasticity and dystonia are associated with higher infection rates in children than in adults. Factors unique to this population, such as poor nutrition and physical limitations for pump placement, have been hypothesized as the reasons for this disparity. The authors assessed potential risk factors for infection in a multivariate analysis. METHODS Patients who underwent implantation of a programmable pump and intrathecal catheter for baclofen infusion at a single center between January 1, 2000, and March 1, 2012, were identified in this retrospective cohort study. The primary end point was infection. Potential risk factors investigated included preoperative (i.e., demographics, body mass index [BMI], gastrostomy tube, tracheostomy, previous spinal fusion), intraoperative (i.e., surgeon, antibiotics, pump size, catheter location), and postoperative (i.e., wound dehiscence, CSF leak, and number of revisions) factors. Univariate analysis was performed, and a multivariate logistic regression model was created to identify independent risk factors for infection. RESULTS A total of 254 patients were evaluated. The overall infection rate was 9.8%. Univariate analysis identified young age, shorter height, lower weight, dehiscence, CSF leak, and number of revisions within 6 months of pump placement as significantly associated with infection. Multivariate analysis identified young age, dehiscence, and number of revisions as independent risk factors for infection. CONCLUSIONS Young age, wound dehiscence, and number of revisions were independent risk factors for infection in this pediatric cohort. A low BMI and the presence of either a gastrostomy or tracheostomy were not associated with infection and may not be contraindications for this procedure.

Size distributions of secondary and primary aerosols in Asia: A 3-D modeling

NASA Astrophysics Data System (ADS)

Yu, F.; Luo, G.; Wang, Z.

2009-12-01

Asian aerosols have received increasing attention because of their potential health and climate effects and the rapid increasing of Asian emissions associated with accelerating economic expansion. Aerosol particles appear in the atmosphere due to either in-situ nucleation (i.e, secondary particles) or direct emissions (i.e., primary particles), and their environmental impacts depend strongly on their concentrations, sizes, compositions, and mixing states. A size-resolved (sectional) particle microphysics model with a number of computationally efficient schemes has been incorporated into a global chemistry transport model (GEOS-Chem) to simulate the number size distributions of secondary and primary particles in the troposphere (Yu and Luo, Atmos. Chem. Phys. Discuss., 9, 10597-10645, 2009). The growth of nucleated particles through the condensation of sulfuric acid vapor and equilibrium uptake of nitrate, ammonium, and secondary organic aerosol is explicitly simulated, along with the coating of primary particles (dust, black carbon, organic carbon, and sea salt) by volatile components via condensation and coagulation with secondary particles. Here we look into the spatiotemporal variations of the size distributions of secondary and primary aerosols in Asia. The annual mean number concentration of the accumulation mode particles (dry diameter > ~ 100 nm) in the lower troposphere over Asia (especially China) is very high and is dominated (~70-90%) by carbonaceous primary particles (with coated condensable species). Coagulation and condensation turn the primary particles into mixed particles and on average increase the dry sizes of primary particles by a factor of ~ 2-2.5. Despite of high condensation sink, sulfuric acid vapor concentration in many parts of Asian low troposphere is very high (annual mean values above 1E7/cm3) and significant new particle formation still occurs. Secondary particles generally dominate the particles small than 100 nm and the equilibrium uptake of nitrate, ammonium, and secondary organic aerosol contributes significantly to the growth of these particles. The vertical profiles of particle number size distributions at representative locations show significant spatial variations (both horizontally and vertically). Our simulations also indicate substantial seasonal variations of particle size distributions.

Spatial Light Modulators and Applications: Summaries of Papers Presented at the Spatial Light Modulators and Applications Topical Meeting Held on March 15-17, 1993 in Palm Springs, California

DTIC Science & Technology

1993-03-17

modulator: Number of Elements 16 x 16 Pixel Size 1 mmxl mm Area Fill Factor > 90% Reflectance > 90% Phase Shift 900 Frame Rate > 1 kHz Operational Spectral...electro-optic constants. By using reflected light from the second interface a factor of two increase in phase shift is obtained for an applied voltage vs...wavelengths in general require thinner PLZT wafers. One of the objectives of the SLM design was to maximize pixel area fill factor and thereby the

The influence of mare numbers, ejaculation frequency and month on the fertility of Thoroughbred stallions.

PubMed

Allen, W R; Wilsher, S

2012-09-01

Although considerable variation in per cycle pregnancy rates exists between Thoroughbred (TB) stallions, there is little information on factors that may influence this figure. To assess the influence of month, mare numbers and mating frequency on the fertility of TB stallions standing on studfarms in East Anglia, England. The daily breeding records of 31 TB stallions mating 3034 mares on 4851 occasions during the 2010 season were surveyed and related to first scan pregnancy rates. The influences of mare book size, month, number of matings per day and mating frequency or abstinence on per mating pregnancy rates were analysed. The overall per mating pregnancy rate for all the stallions was 59.6%, but for individual stallions the figures ranged from 19.0% to 80.1%. The first mating occurred on 9 February and the last on 24 July and the per mating pregnancy rate per month was significantly reduced in June and July. The number of mares mated by individual stallions ranged from 15 to 161, giving a mean overall workload of 160 matings per 100 mares. The per mating pregnancy rate was not related to book size, the number of matings in the season or the mating frequency per day. However, some stallions showed differences in per mating pregnancy rate related to month or the number of ejaculations in the preceding 3 days. The majority of TB stallions are able to maintain good fertility despite large books of mares. However, 5 of the 31 stallions surveyed showed a per mating pregnancy rate of ≤50%. This survey has identified wide differences between the per mating pregnancy rate in TB stallions. Identification of the factors involved through more comprehensive surveys would provide useful information for mare and stallion owners. © 2011 EVJ Ltd.

Scattering from phase-separated vesicles. I. An analytical form factor for multiple static domains

DOE PAGES

Heberle, Frederick A.; Anghel, Vinicius N. P.; Katsaras, John

2015-08-18

This is the first in a series of studies considering elastic scattering from laterally heterogeneous lipid vesicles containing multiple domains. Unique among biophysical tools, small-angle neutron scattering can in principle give detailed information about the size, shape and spatial arrangement of domains. A general theory for scattering from laterally heterogeneous vesicles is presented, and the analytical form factor for static domains with arbitrary spatial configuration is derived, including a simplification for uniformly sized round domains. The validity of the model, including series truncation effects, is assessed by comparison with simulated data obtained from a Monte Carlo method. Several aspects ofmore » the analytical solution for scattering intensity are discussed in the context of small-angle neutron scattering data, including the effect of varying domain size and number, as well as solvent contrast. Finally, the analysis indicates that effects of domain formation are most pronounced when the vesicle's average scattering length density matches that of the surrounding solvent.« less

Modeling particle nucleation and growth over northern California during the 2010 CARES campaign

NASA Astrophysics Data System (ADS)

Lupascu, A.; Easter, R.; Zaveri, R.; Shrivastava, M.; Pekour, M.; Tomlinson, J.; Yang, Q.; Matsui, H.; Hodzic, A.; Zhang, Q.; Fast, J. D.

2015-11-01

Accurate representation of the aerosol lifecycle requires adequate modeling of the particle number concentration and size distribution in addition to their mass, which is often the focus of aerosol modeling studies. This paper compares particle number concentrations and size distributions as predicted by three empirical nucleation parameterizations in the Weather Research and Forecast coupled with chemistry (WRF-Chem) regional model using 20 discrete size bins ranging from 1 nm to 10 μm. Two of the parameterizations are based on H2SO4, while one is based on both H2SO4 and organic vapors. Budget diagnostic terms for transport, dry deposition, emissions, condensational growth, nucleation, and coagulation of aerosol particles have been added to the model and are used to analyze the differences in how the new particle formation parameterizations influence the evolving aerosol size distribution. The simulations are evaluated using measurements collected at surface sites and from a research aircraft during the Carbonaceous Aerosol and Radiative Effects Study (CARES) conducted in the vicinity of Sacramento, California. While all three parameterizations captured the temporal variation of the size distribution during observed nucleation events as well as the spatial variability in aerosol number, all overestimated by up to a factor of 2.5 the total particle number concentration for particle diameters greater than 10 nm. Using the budget diagnostic terms, we demonstrate that the combined H2SO4 and low-volatility organic vapor parameterization leads to a different diurnal variability of new particle formation and growth to larger sizes compared to the parameterizations based on only H2SO4. At the CARES urban ground site, peak nucleation rates are predicted to occur around 12:00 Pacific (local) standard time (PST) for the H2SO4 parameterizations, whereas the highest rates were predicted at 08:00 and 16:00 PST when low-volatility organic gases are included in the parameterization. This can be explained by higher anthropogenic emissions of organic vapors at these times as well as lower boundary-layer heights that reduce vertical mixing. The higher nucleation rates in the H2SO4-organic parameterization at these times were largely offset by losses due to coagulation. Despite the different budget terms for ultrafine particles, the 10-40 nm diameter particle number concentrations from all three parameterizations increased from 10:00 to 14:00 PST and then decreased later in the afternoon, consistent with changes in the observed size and number distribution. We found that newly formed particles could explain up to 20-30 % of predicted cloud condensation nuclei at 0.5 % supersaturation, depending on location and the specific nucleation parameterization. A sensitivity simulation using 12 discrete size bins ranging from 1 nm to 10 μm diameter gave a reasonable estimate of particle number and size distribution compared to the 20 size bin simulation, while reducing the associated computational cost by ~ 36 %.

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

Haaland, C.M.; Wigner, E.P.

Given a number of short-range anti-ballistic missiles (ABM), one would like to distribute them among the possible targets in such a way as to minimize the fatalities which an attacker can cause. This mini-max problem is solved by an elementary mathematical method. There is an optimal distribution of the defending missiles which remains optimal independent of the size of the attack, provided the total number of defending missiles and the number of targets are reasonably large. Calculations for the U.S. indicate that the number of fatalities can be further reduced by a factor of 4 to 7 by means ofmore » passive defense, i.e., blast shelters, similar to those under Chinese cities.« less

Magnetization measurements on multifilamentary No/sub 3/Sn and NbTi conductors

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

Ghosh, A.K.; Robins, K.E.; Sampson, W.B.

1985-03-01

The effective filament size has been determined for a number of high current Nb/sub 3/Sn multifilamentary composites. In most cases it is much larger than the nominal filament size. For the smallest filaments (..integral.. 1 micron) the effective size can be as much as a factor of forty times the nominal size. Samples made by the ''internal tin'', ''bronze route'', and ''jelly roll'' methods have been examined with filaments in the range one to ten microns. Rate dependent magnetization and ''flux'' jumping'' have been observed in some cases. NbTi composites ranging in filament size from nine to two hundred micronsmore » and with copper to super-conductor ratios between 1.6:1 and 7:1 have been examined in the same apparatus. Low field ''flux jumping'' was only observed in conductors with very large filaments and relatively little stabilizing copper.« less

Beliefs about penis size: validation of a scale for men ashamed about their penis size.

PubMed

Veale, David; Eshkevari, Ertimiss; Read, Julie; Miles, Sarah; Troglia, Andrea; Phillips, Rachael; Echeverria, Lina Maria Carmona; Fiorito, Chiara; Wylie, Kevan; Muir, Gordon

2014-01-01

No measures are available for understanding beliefs in men who experience shame about the perceived size of their penis. Such a measure might be helpful for treatment planning, and measuring outcome after any psychological or physical intervention. Our aim was to validate a newly developed measure called the Beliefs about Penis Size Scale (BAPS). One hundred seventy-three male participants completed a new questionnaire consisting of 18 items to be validated and developed into the BAPS, as well as various other standardized measures. A urologist also measured actual penis size. The BAPS was validated against six psychosexual self-report questionnaires as well as penile size measurements. Exploratory factor analysis reduced the number of items in the BAPS from 18 to 10, which was best explained by one factor. The 10-item BAPS had good internal consistency and correlated significantly with measures of depression, anxiety, body image quality of life, social anxiety, erectile function, overall satisfaction, and the importance attached to penis size. The BAPS was not found to correlate with actual penis size. It was able to discriminate between those who had concerns or were dissatisfied about their penis size and those who were not. This is the first study to develop a scale for measurement of beliefs about penis size. It may be used as part of an assessment for men who experience shame about the perceived size of their penis and as an outcome measure after treatment. The BAPS measures various manifestations of masculinity and shame about their perceived penis size including internal self-evaluative beliefs; negative evaluation by others; anticipated consequences of a perceived small penis, and extreme self-consciousness. © 2013 International Society for Sexual Medicine.

The subtle intracapsular survival of the fittest: maternal investment, sibling conflict, or environmental effects?

PubMed

Smith, Kathryn E; Thatje, Sven

2013-10-01

Developmental resource partitioning and the consequent offspring size variations are of fundamental importance for marine invertebrates, in both an ecological and evolutionary context. Typically, differences are attributed to maternal investment and the environmental factors determining this; additional variables, such as environmental factors affecting development, are rarely discussed. During intracapsular development, for example, sibling conflict has the potential to affect resource partitioning. Here, we investigate encapsulated development in the marine gastropod Buccinum undatum. We examine the effects of maternal investment and temperature on intracapsular resource partitioning in this species. Reproductive output was positively influenced by maternal investment, but additionally, temperature and sibling conflict significantly affected offspring size, number, and quality during development. Increased temperature led to reduced offspring number, and a combination of high sibling competition and asynchronous early development resulted in a common occurrence of "empty" embryos, which received no nutrition at all. The proportion of empty embryos increased with both temperature and capsule size. Additionally, a novel example ofa risk in sibling conflict was observed; embryos cannibalized by others during early development ingested nurse eggs from inside the consumer, killing it in a "Trojan horse" scenario. Our results highlight the complexity surrounding offspring fitness. Encapsulation should be considered as significant in determining maternal output. Considering predicted increases in ocean temperatures, this may impact offspring quality and consequently species distribution and abundance.

Human population, grasshopper and plant species richness in European countries

NASA Astrophysics Data System (ADS)

Steck, Claude E.; Pautasso, Marco

2008-11-01

Surprisingly, several studies over large scales have reported a positive spatial correlation of people and biodiversity. This pattern has important implications for conservation and has been documented for well studied taxa such as plants, amphibians, reptiles, birds and mammals. However, it is unknown whether the pattern applies also to invertebrates other than butterflies and more work is needed to establish whether the species-people relationship is explained by both variables correlating with other environmental factors. We studied whether grasshopper species richness (Orthoptera, suborder Caelifera) is related to human population size in European countries. As expected, the number of Caelifera species increases significantly with increasing human population size. But this is not the case when controlling for country area, latitude and number of plant species. Variations in Caelifera species richness are primarily associated with variations in plant species richness. Caelifera species richness also increases with decreasing mean annual precipitation, Gross Domestic Product per capita (used as an indicator for economic development) and net fertility rate of the human population. Our analysis confirms the hypothesis that the broad-scale human population-biodiversity correlations can be explained by concurrent variations in factors other than human population size such as plant species richness, environmental productivity, or habitat heterogeneity. Nonetheless, more populated countries in Europe still have more Caelifera species than less populated countries and this poses a particular challenge for conservation.

Experimental tsunami deposits: Linking hydrodynamics to sediment entrainment, advection lengths and downstream fining

NASA Astrophysics Data System (ADS)

Johnson, Joel P. L.; Delbecq, Katie; Kim, Wonsuck; Mohrig, David

2016-01-01

A goal of paleotsunami research is to quantitatively reconstruct wave hydraulics from sediment deposits in order to better understand coastal hazards. Simple models have been proposed to predict wave heights and velocities, based largely on deposit grain size distributions (GSDs). Although seemingly consistent with some recent tsunamis, little independent data exist to test these equations. We conducted laboratory experiments to evaluate inversion assumptions and uncertainties. A computer-controlled lift gate instantaneously released 6.5 m3 of water into a 32 m flume with shallow ponded water, creating a hydraulic bore that transported sand from an upstream source dune. Differences in initial GSDs and ponded water depths influenced entrainment, transport, and deposition. While the source dune sand was fully suspendable based on size alone, experimental tsunamis produced deposits dominated by bed load sand transport in the upstream 1/3 of the flume and suspension-dominated transport downstream. The suspension deposits exhibited downstream fining and thinning. At 95% confidence, a published advection-settling model predicts time-averaged flow depths to approximately a factor of two, and time-averaged downstream flow velocities to within a factor of 1.5. Finally, reasonable scaling is found between flume and field cases by comparing flow depths, inundation distances, Froude numbers, Rouse numbers and grain size trends in suspension-dominated tsunami deposits, justifying laboratory study of sediment transport and deposition by tsunamis.

Association of serum electrolytes and smoking with salivary gland stone formation.

PubMed

Yiu, A J; Kalejaiye, A; Amdur, R L; Todd Hesham, H N; Bandyopadhyay, B C

2016-06-01

To further define potential factors that may contribute to stone formation in salivary glands (sialolithiasis), a retrospective chart review was performed of patients diagnosed with sialolithiasis between March 1, 1998 and February 29, 2012. Information on salivary gland stone number, location and size, medical history, medications, and serum electrolyte levels were collected. Associations between electrolyte levels and stone characteristics (such as stone number and size) were examined. Fifty-nine patients were identified; their median age was 58 years (range 25-89 years) and most were male (95%). Salivary stones were most commonly located in the submandibular glands (83%). Thirty-five patients (59%) had a smoking history, with 16 (27%) reported as current smokers. There was a significant association between current smoker status and stone size (mean largest stone size 12.4±8.8mm vs. 7.5±4.8mm in current smokers vs. non-smokers; P=0.03). Serum sodium levels (r=0.32, P=0.014) and serum potassium levels (r=0.31, P=0.017) showed significant positive correlations with stone size. While the aetiology of sialolithiasis remains unclear, smoking (which can contribute to reduced saliva flow) and higher serum sodium levels (which can reflect volume depletion) are associated with larger salivary stones. Published by Elsevier Ltd.

Estimation method for serial dilution experiments.

PubMed

Ben-David, Avishai; Davidson, Charles E

2014-12-01

Titration of microorganisms in infectious or environmental samples is a corner stone of quantitative microbiology. A simple method is presented to estimate the microbial counts obtained with the serial dilution technique for microorganisms that can grow on bacteriological media and develop into a colony. The number (concentration) of viable microbial organisms is estimated from a single dilution plate (assay) without a need for replicate plates. Our method selects the best agar plate with which to estimate the microbial counts, and takes into account the colony size and plate area that both contribute to the likelihood of miscounting the number of colonies on a plate. The estimate of the optimal count given by our method can be used to narrow the search for the best (optimal) dilution plate and saves time. The required inputs are the plate size, the microbial colony size, and the serial dilution factors. The proposed approach shows relative accuracy well within ±0.1log10 from data produced by computer simulations. The method maintains this accuracy even in the presence of dilution errors of up to 10% (for both the aliquot and diluent volumes), microbial counts between 10(4) and 10(12) colony-forming units, dilution ratios from 2 to 100, and plate size to colony size ratios between 6.25 to 200. Published by Elsevier B.V.

Association of serum electrolytes and smoking with salivary gland stone formation

PubMed Central

Yiu, A. J.; Kalejaiye, A.; Amdur, R. L.; Hesham, H. N. Todd; Bandyopadhyay, B. C.

2016-01-01

To further define potential factors that may contribute to stone formation in salivary glands (sialolithiasis), a retrospective chart review was performed of patients diagnosed with sialolithiasis between March 1, 1998 and February 29, 2012. Information on salivary gland stone number, location, and size, medical history, medications, and serum electrolyte levels were collected. Associations between electrolyte levels and stone characteristics (such as stone number and size) were examined. Fifty-nine patients were identified; their median age was 58 years (range 25–89 years) and most were male (95%). Salivary stones were most commonly located in the submandibular glands (83%). Thirty-five patients (59%) had a smoking history, with 16 (27%) reported as current smokers. There was a significant association between current smoker status and stone size (mean largest stone size 12.4 ± 8.8 mm vs. 7.5 ± 4.8 mm in current smokers vs. non-smokers; P = 0.03). Serum sodium levels (r = 0.32, P = 0.014) and serum potassium levels (r = 0.31, P = 0.017) showed significant positive correlations with stone size. While the etiology of sialolithiasis remains unclear, smoking (which can contribute to reduced saliva flow) and higher serum sodium levels (which can reflect volume depletion) are associated with larger salivary stones. PMID:26969301

Reproductive Potential of Salmon Spawning Substrates Inferred from Grain Size and Fish Length

NASA Astrophysics Data System (ADS)

Riebe, C. S.; Sklar, L. S.; Overstreet, B. T.; Wooster, J. K.; Bellugi, D. G.

2014-12-01

The river restoration industry spends millions of dollars every year on improving salmon spawning in riverbeds where sediment is too big for fish to move and thus use during redd building. However, few studies have addressed the question of how big is too big in salmon spawning substrates. Hence managers have had little quantitative basis for gauging the amount of spawning habitat in coarse-bedded rivers. Moreover, the scientific framework has remained weak for restoration projects that seek to improve spawning conditions. To overcome these limitations, we developed a physically based, field-calibrated model for the fraction of the bed that is fine-grained enough to support spawning by fish of a given size. Model inputs are fish length and easy-to-measure indices of bed-surface grain size. Model outputs include the number of redds and eggs the substrate can accommodate when flow depth, temperature, and other environmental factors are not limiting. The mechanistic framework of the model captures the biophysical limits on sediment movement and the space limitations on redd building and egg deposition in riverbeds. We explored the parameter space of the model and found a previously unrecognized tradeoff in salmon size: bigger fish can move larger sediment and thus use more riverbed area for spawning; they also tend to have higher fecundity, and so can deposit more eggs per redd; however, because redd area increases with fish length, the number of eggs a substrate can accommodate is highest for moderate-sized fish. One implication of this tradeoff is that differences in grain size may help regulate river-to-river differences in salmon size. Thus, our model suggests that population diversity and, by extension, species resilience are linked to lithologic, geomorphic, and climatic factors that determine grain size in rivers. We cast the model into easy-to-use look-up tables, charts, and computer applications, including a JavaScript app that works on tablets and mobile phones. We explain how these tools can be used in a new, mechanistic approach to assessing spawning substrates and optimizing gravel augmentation projects in coarse-bedded rivers.

Determining the optimal vaccine vial size in developing countries: a Monte Carlo simulation approach.

PubMed

Dhamodharan, Aswin; Proano, Ruben A

2012-09-01

Outreach immunization services, in which health workers immunize children in their own communities, are indispensable to improve vaccine coverage in rural areas of developing countries. One of the challenges faced by these services is how to reduce high levels of vaccine wastage. In particular, the open vial wastage (OVW) that result from the vaccine doses remaining in a vial after a time for safe use -since opening the vial- has elapsed. This wastage is highly dependent on the choice of vial size and the expected number of participants for which the outreach session is planned (i.e., session size). The use single-dose vials results in zero OVW, but it increases the vaccine purchase, transportation, and holding costs per dose as compared to those resulting from using larger vial sizes. The OVW also decreases when more people are immunized in a session. However, controlling the actual number of people that show to an outreach session in rural areas of developing countries highly depends on factors that are out of control of the immunization planners. This paper integrates a binary integer-programming model to a Monte Carlo simulation method to determine the choice of vial size and the optimal reordering point level to implement an (nQ, r, T) lot-sizing policy that provides the best tradeoff between procurement costs and wastage.

Group size and visitor numbers predict faecal glucocorticoid concentrations in zoo meerkats

PubMed Central

Scott, Katy; Heistermann, Michael

2017-01-01

Measures of physiological stress in zoo animals can give important insights into how they are affected by aspects of their captive environment. We analysed the factors influencing variation in glucocorticoid metabolites in faeces (fGCs) from zoo meerkats as a proxy for blood cortisol concentration, high levels of which are associated with a stress response. Levels of fGCs in captive meerkats declined with increasing group size. In the wild, very small groups of meerkats are at a higher risk of predation, while in larger groups, there is increased competition for resources. Indeed, group sizes in captivity resemble those seen in unstable coalitions in the wild, which may represent a stressful condition and predispose meerkats to chronic stress, even in the absence of natural predators. Individuals in large enclosures showed lower levels of stress, but meerkat density had no effect on the stress measures. In contrast with data from wild meerkats, neither sex, age nor dominance status predicted stress levels, which may reflect less food stress owing to more equal access to resources in captivity versus wild. The median number of visitors at the enclosure was positively correlated with fGC concentrations on the following day, with variation in the visitor numbers having the opposite effect. Our results are consistent with the hypothesis that there is an optimum group size which minimizes physiological stress in meerkats, and that zoo meerkats at most risk of physiological stress are those kept in small groups and small enclosures and are exposed to consistently high numbers of visitors. PMID:28484620

Group size and visitor numbers predict faecal glucocorticoid concentrations in zoo meerkats.

PubMed

Scott, Katy; Heistermann, Michael; Cant, Michael A; Vitikainen, Emma I K

2017-04-01

Measures of physiological stress in zoo animals can give important insights into how they are affected by aspects of their captive environment. We analysed the factors influencing variation in glucocorticoid metabolites in faeces (fGCs) from zoo meerkats as a proxy for blood cortisol concentration, high levels of which are associated with a stress response. Levels of fGCs in captive meerkats declined with increasing group size. In the wild, very small groups of meerkats are at a higher risk of predation, while in larger groups, there is increased competition for resources. Indeed, group sizes in captivity resemble those seen in unstable coalitions in the wild, which may represent a stressful condition and predispose meerkats to chronic stress, even in the absence of natural predators. Individuals in large enclosures showed lower levels of stress, but meerkat density had no effect on the stress measures. In contrast with data from wild meerkats, neither sex, age nor dominance status predicted stress levels, which may reflect less food stress owing to more equal access to resources in captivity versus wild. The median number of visitors at the enclosure was positively correlated with fGC concentrations on the following day, with variation in the visitor numbers having the opposite effect. Our results are consistent with the hypothesis that there is an optimum group size which minimizes physiological stress in meerkats, and that zoo meerkats at most risk of physiological stress are those kept in small groups and small enclosures and are exposed to consistently high numbers of visitors.

Application of a hurdle negative binomial count data model to demand for bass fishing in the southeastern United States.

PubMed

Bilgic, Abdulbaki; Florkowski, Wojciech J

2007-06-01

This paper identifies factors that influence the demand for a bass fishing trip taken in the southeastern United States using a hurdle negative binomial count data model. The probability of fishing for a bass is estimated in the first stage and the fishing trip frequency is estimated in the second stage for individuals reporting bass fishing trips in the Southeast. The applied approach allows the decomposition of the effects of factors responsible for the decision to take a trip and the trip number. Calculated partial and total elasticities indicate a highly inelastic demand for the number of fishing trips as trip costs increase. However, the demand can be expected to increase if anglers experience a success measured by the number of caught fish or their size. Benefit estimates based on alternative estimation methods differ substantially, suggesting the need for testing each modeling approach applied in empirical studies.

A synthesis of studies of access point density as a risk factor for road accidents.

PubMed

Elvik, Rune

2017-10-01

Studies of the relationship between access point density (number of access points, or driveways, per kilometre of road) and accident frequency or rate (number of accidents per unit of exposure) have consistently found that accident rate increases when access point density increases. This paper presents a formal synthesis of the findings of these studies. It was found that the addition of one access point per kilometre of road is associated with an increase of 4% in the expected number of accidents, controlling for traffic volume. Although studies consistently indicate an increase in accident rate as access point density increases, the size of the increase varies substantially between studies. In addition to reviewing studies of access point density as a risk factor, the paper discusses some issues related to formally synthesising regression coefficients by applying the inverse-variance method of meta-analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimization of BI test parameters to investigate mechanical properties of Grade 92 steel

NASA Astrophysics Data System (ADS)

Barbadikar, Dipika R.; Vincent, S.; Ballal, Atul R.; Peshwe, Dilip R.; Mathew, M. D.

2018-04-01

The ball indentation (BI) testing is used to evaluate the tensile properties of materials namely yield strength, strength coefficient, ultimate tensile strength, and strain hardening exponent. The properties evaluated depend on a number of BI test parameters. These parameters include the material constants like yield slope (YS), constraint factor (CF), yield offset parameter (YOP). Number of loading/unloading cycles, preload, indenter size and depth of penetration of indenter also affects the properties. In present investigation the effect of these parameters on the stress-strain curve of normalized and tempered Grade 92 steel is evaluated. Grade 92 is a candidate material for power plant application over austenitic stainless steel and derives its strength from M23C6, MX precipitates and high dislocation density. CF, YS and YOP changed the strength properties considerably. Indenter size effect resulted in higher strength for smaller indenter. It is suggested to use larger indenter diameter and higher number of loading cycles for GRADE 92 steel to get best results using BI technique.

School Safety: Safer Schools with Different Kinds of Safety Personnel

ERIC Educational Resources Information Center

Herreras, Henry

2013-01-01

The purpose of this study was to investigate the difference between the total number of education code violations and the security personnel assigned by the school district. This study also proposed to examine factors such as socio-economic level of the district, the size of the district, and its location. Due to the increase in violence in…

Advanced Multi-Moment Microphysics for Precipitation and Tropical Cyclone Forecast Improvement within COAMPS

DTIC Science & Technology

2010-09-30

of predicting up to three moments (total number concentration, mass, and the 6th-moment reflectivity factor) of hydrometeor hydrometeor particle size...R. Novak, F. E. Barthold, M. J. Bodner, J. J. Levit , C. B. Entwistle, T. Jensen, J. S. Kain, M. C. Coniglio, and R. S. Schneider, 2010: An overview

Handling Missing Data in Educational Research Using SPSS

ERIC Educational Resources Information Center

Cheema, Jehanzeb

2012-01-01

This study looked at the effect of a number of factors such as the choice of analytical method, the handling method for missing data, sample size, and proportion of missing data, in order to evaluate the effect of missing data treatment on accuracy of estimation. In order to accomplish this a methodological approach involving simulated data was…

Gene flow analysis method, the D-statistic, is robust in a wide parameter space.

PubMed

Zheng, Yichen; Janke, Axel

2018-01-08

We evaluated the sensitivity of the D-statistic, a parsimony-like method widely used to detect gene flow between closely related species. This method has been applied to a variety of taxa with a wide range of divergence times. However, its parameter space and thus its applicability to a wide taxonomic range has not been systematically studied. Divergence time, population size, time of gene flow, distance of outgroup and number of loci were examined in a sensitivity analysis. The sensitivity study shows that the primary determinant of the D-statistic is the relative population size, i.e. the population size scaled by the number of generations since divergence. This is consistent with the fact that the main confounding factor in gene flow detection is incomplete lineage sorting by diluting the signal. The sensitivity of the D-statistic is also affected by the direction of gene flow, size and number of loci. In addition, we examined the ability of the f-statistics, [Formula: see text] and [Formula: see text], to estimate the fraction of a genome affected by gene flow; while these statistics are difficult to implement to practical questions in biology due to lack of knowledge of when the gene flow happened, they can be used to compare datasets with identical or similar demographic background. The D-statistic, as a method to detect gene flow, is robust against a wide range of genetic distances (divergence times) but it is sensitive to population size. The D-statistic should only be applied with critical reservation to taxa where population sizes are large relative to branch lengths in generations.

Modeling particle nucleation and growth over northern California during the 2010 CARES campaign

NASA Astrophysics Data System (ADS)

Lupascu, A.; Easter, R.; Zaveri, R.; Shrivastava, M.; Pekour, M.; Tomlinson, J.; Yang, Q.; Matsui, H.; Hodzic, A.; Zhang, Q.; Fast, J. D.

2015-07-01

Accurate representation of the aerosol lifecycle requires adequate modeling of the particle number concentration and size distribution in addition to their mass, which is often the focus of aerosol modeling studies. This paper compares particle number concentrations and size distributions as predicted by three empirical nucleation parameterizations in the Weather Research and Forecast coupled with chemistry (WRF-Chem) regional model using 20 discrete size bins ranging from 1 nm to 10 μm. Two of the parameterizations are based on H2SO4 while one is based on both H2SO4 and organic vapors. Budget diagnostic terms for transport, dry deposition, emissions, condensational growth, nucleation, and coagulation of aerosol particles have been added to the model and are used to analyze the differences in how the new particle formation parameterizations influence the evolving aerosol size distribution. The simulations are evaluated using measurements collected at surface sites and from a research aircraft during the Carbonaceous Aerosol and Radiative Effects Study (CARES) conducted in the vicinity of Sacramento, California. While all three parameterizations captured the temporal variation of the size distribution during observed nucleation events as well as the spatial variability in aerosol number, all overestimated by up to a factor of 2.5 the total particle number concentration for particle diameters greater than 10 nm. Using the budget diagnostic terms, we demonstrate that the combined H2SO4 and low-volatility organic vapors parameterization leads to a different diurnal variability of new particle formation and growth to larger sizes compared to the parameterizations based on only H2SO4. At the CARES urban ground site, peak nucleation rates were predicted to occur around 12:00 Pacific (local) standard time (PST) for the H2SO4 parameterizations, whereas the highest rates were predicted at 08:00 and 16:00 PST when low-volatility organic gases are included in the parameterization. This can be explained by higher anthropogenic emissions of organic vapors at these times as well as lower boundary layer heights that reduce vertical mixing. The higher nucleation rates in the H2SO4-organic parameterization at these times were largely offset by losses due to coagulation. Despite the different budget terms for ultrafine particles, the 10-40 nm diameter particle number concentrations from all three parameterizations increased from 10:00 to 14:00 PST and then decreased later in the afternoon, consistent with changes in the observed size and number distribution. Differences among the three simulations for the 40-100 nm particle diameter range are mostly associated with the timing of the peak total tendencies that shift the morning increase and afternoon decrease in particle number concentration by up to two hours. We found that newly formed particles could explain up to 20-30 % of predicted cloud condensation nuclei at 0.5 % supersaturation, depending on location and the specific nucleation parameterization. A sensitivity simulation using 12 discrete size bins ranging from 1 nm to 10 μm diameter gave a reasonable estimate of particle number and size distribution compared to the 20 size bin simulation, while reducing the associated computational cost by ∼ 36 %.

A Monte-Carlo simulation analysis for evaluating the severity distribution functions (SDFs) calibration methodology and determining the minimum sample-size requirements.

PubMed

Shirazi, Mohammadali; Reddy Geedipally, Srinivas; Lord, Dominique

2017-01-01

Severity distribution functions (SDFs) are used in highway safety to estimate the severity of crashes and conduct different types of safety evaluations and analyses. Developing a new SDF is a difficult task and demands significant time and resources. To simplify the process, the Highway Safety Manual (HSM) has started to document SDF models for different types of facilities. As such, SDF models have recently been introduced for freeway and ramps in HSM addendum. However, since these functions or models are fitted and validated using data from a few selected number of states, they are required to be calibrated to the local conditions when applied to a new jurisdiction. The HSM provides a methodology to calibrate the models through a scalar calibration factor. However, the proposed methodology to calibrate SDFs was never validated through research. Furthermore, there are no concrete guidelines to select a reliable sample size. Using extensive simulation, this paper documents an analysis that examined the bias between the 'true' and 'estimated' calibration factors. It was indicated that as the value of the true calibration factor deviates further away from '1', more bias is observed between the 'true' and 'estimated' calibration factors. In addition, simulation studies were performed to determine the calibration sample size for various conditions. It was found that, as the average of the coefficient of variation (CV) of the 'KAB' and 'C' crashes increases, the analyst needs to collect a larger sample size to calibrate SDF models. Taking this observation into account, sample-size guidelines are proposed based on the average CV of crash severities that are used for the calibration process. Copyright © 2016 Elsevier Ltd. All rights reserved.

The changing food outlet distributions and local contextual factors in the United States.

PubMed

Chen, Hsin-Jen; Wang, Youfa

2014-01-16

Little is known about the dynamics of the food outlet distributions associated with local contextual factors in the U.S. This study examines the changes in food stores/services at the 5-digit Zip Code Tabulated Area (ZCTA5) level in the U.S., and assesses contextual factors associated with the changes. Data from 27,878 ZCTA5s in the contiguous United States without an extreme change in the number of 6 types of food stores/services (supermarkets, small-size grocery stores, convenience stores, fresh/specialty food markets, carry-out restaurants, and full-service restaurants) were used. ZCTA5s' contextual factors were from the 2000 Census. Numbers of food stores/services were derived from the Census Business Pattern databases. Linear regression models assessed contextual factors' influences (racial/ethnic compositions, poverty rate, urbanization level, and foreign-born population%) on 1-year changes in food stores/services during 2000-2001, adjusted for population size, total business change, and census regions. Small-size grocery stores and fresh/specialty food markets increased more and convenience stores decreased more in Hispanic-predominant than other areas. Among supermarket-free places, new supermarkets were less likely to be introduced into black-predominant than white-predominant areas (odds ratio (OR) = 0.52, 95% CI = 0.30-0.92). However, among areas without the following type of store at baseline, supermarket (OR = 0.48 (0.33-0.70)), small-size grocery stores (OR = 1.32 (1.08-1.62)), and fresh/specialty food markets (OR = 0.70 (0.53-0.92)) were less likely to be introduced into areas of low foreign-born population than into areas of high foreign-born population. Higher poverty rate was associated with a greater decrease in supermarket, a less decrease in small-size grocery stores, and a less increase in carry-out restaurants (all p for trends <0.001). Urban areas experienced more increases in full-service and carry-out restaurants than suburban areas. Local area characteristics affect 1-year changes in food environment in the U.S. Hispanic population was associated with more food stores/services capable of supplying fresh food items. Black-predominant and poverty-afflicted areas had a greater decrease in supermarkets. Full-service and carry-out restaurants increased more in urban than suburban areas. Foreign-born population density was associated with introduction of grocery stores and fresh/specialty food markets into the areas.

BCYCLIC: A parallel block tridiagonal matrix cyclic solver

NASA Astrophysics Data System (ADS)

Hirshman, S. P.; Perumalla, K. S.; Lynch, V. E.; Sanchez, R.

2010-09-01

A block tridiagonal matrix is factored with minimal fill-in using a cyclic reduction algorithm that is easily parallelized. Storage of the factored blocks allows the application of the inverse to multiple right-hand sides which may not be known at factorization time. Scalability with the number of block rows is achieved with cyclic reduction, while scalability with the block size is achieved using multithreaded routines (OpenMP, GotoBLAS) for block matrix manipulation. This dual scalability is a noteworthy feature of this new solver, as well as its ability to efficiently handle arbitrary (non-powers-of-2) block row and processor numbers. Comparison with a state-of-the art parallel sparse solver is presented. It is expected that this new solver will allow many physical applications to optimally use the parallel resources on current supercomputers. Example usage of the solver in magneto-hydrodynamic (MHD), three-dimensional equilibrium solvers for high-temperature fusion plasmas is cited.

X-ray clusters from a high-resolution hydrodynamic PPM simulation of the cold dark matter universe

NASA Technical Reports Server (NTRS)

Bryan, Greg L.; Cen, Renyue; Norman, Michael L.; Ostriker, Jermemiah P.; Stone, James M.

1994-01-01

A new three-dimensional hydrodynamic code based on the piecewise parabolic method (PPM) is utilized to compute the distribution of hot gas in the standard Cosmic Background Explorer (COBE)-normalized cold dark matter (CDM) universe. Utilizing periodic boundary conditions, a box with size 85 h(exp-1) Mpc, having cell size 0.31 h(exp-1) Mpc, is followed in a simulation with 270(exp 3)=10(exp 7.3) cells. Adopting standard parameters determined from COBE and light-element nucleosynthesis, Sigma(sub 8)=1.05, Omega(sub b)=0.06, we find the X-ray-emitting clusters, compute the luminosity function at several wavelengths, the temperature distribution, and estimated sizes, as well as the evolution of these quantities with redshift. The results, which are compared with those obtained in the preceding paper (Kang et al. 1994a), may be used in conjuction with ROSAT and other observational data sets. Overall, the results of the two computations are qualitatively very similar with regard to the trends of cluster properties, i.e., how the number density, radius, and temeprature depend on luminosity and redshift. The total luminosity from clusters is approximately a factor of 2 higher using the PPM code (as compared to the 'total variation diminishing' (TVD) code used in the previous paper) with the number of bright clusters higher by a similar factor. The primary conclusions of the prior paper, with regard to the power spectrum of the primeval density perturbations, are strengthened: the standard CDM model, normalized to the COBE microwave detection, predicts too many bright X-ray emitting clusters, by a factor probably in excess of 5. The comparison between observations and theoretical predictions for the evolution of cluster properties, luminosity functions, and size and temperature distributions should provide an important discriminator among competing scenarios for the development of structure in the universe.

Study on Microstructures and Properties of Porous TiC Ceramics Fabricated by Powder Metallurgy

NASA Astrophysics Data System (ADS)

Ma, Yana; Bao, Chonggao; Han, Longhao; Chen, Jie

2017-02-01

Powder metallurgy process was used to fabricate porous titanium carbide (TiC) ceramics, in which TiC powders were taken as the raw materials, nickel was used as the metallic binder and urea was the space-holder. Microstructure, composition and phase of porous TiC ceramics were characterized by scanning electron microscopy (SEM) and x-ray diffraction (XRD). Flexure strength of the porous TiC ceramics was tested by a three-point bending method. The results show that macropores and micropores coexist in the prepared porous TiC ceramics. Moreover, the pore number, size and distribution in porous TiC ceramics can be controlled on demand. Particularly, the factors such as the number or size of space-holder, compacting pressure and Ni content have significant effect on the porosity and flexure strength.

Size-based emphysema cluster analysis on low attenuation area in 3D volumetric CT: comparison with pulmonary functional test

NASA Astrophysics Data System (ADS)

Lee, Minho; Kim, Namkug; Lee, Sang Min; Seo, Joon Beom; Oh, Sang Young

2015-03-01

To quantify low attenuation area (LAA) of emphysematous regions according to cluster size in 3D volumetric CT data of chronic obstructive pulmonary disease (COPD) patients and to compare these indices with their pulmonary functional test (PFT). Sixty patients with COPD were scanned by a more than 16-multi detector row CT scanner (Siemens Sensation 16 and 64) within 0.75mm collimation. Based on these LAA masks, a length scale analysis to estimate each emphysema LAA's size was performed as follows. At first, Gaussian low pass filter from 30mm to 1mm kernel size with 1mm interval on the mask was performed from large to small size, iteratively. Centroid voxels resistant to the each filter were selected and dilated by the size of the kernel, which was regarded as the specific size emphysema mask. The slopes of area and number of size based LAA (slope of semi-log plot) were analyzed and compared with PFT. PFT parameters including DLco, FEV1, and FEV1/FVC were significantly (all p-value< 0.002) correlated with the slopes (r-values; -0.73, 0.54, 0.69, respectively) and EI (r-values; -0.84, -0.60, -0.68, respectively). In addition, the D independently contributed regression for FEV1 and FEV1/FVC (adjust R sq. of regression study: EI only, 0.70, 0.45; EI and D, 0.71, 0.51, respectively). By the size based LAA segmentation and analysis, we evaluated the Ds of area, number, and distribution of size based LAA, which would be independent factors for predictor of PFT parameters.

Hippo circuitry and the redox modulation of hippo components in cancer cell fate decisions.

PubMed

Ashraf, Asma; Pervaiz, Shazib

2015-12-01

Meticulous and precise control of organ size is undoubtedly one of the most pivotal processes in mammalian development and regeneration along with cell differentiation, morphogenesis and programmed cell death. These processes are strictly regulated by complex and highly coordinated mechanisms to maintain a steady growth state. There are a number of extrinsic and intrinsic factors that dictate the total number and/or size of cells by influencing growth, proliferation, differentiation and cell death. Multiple pathways, such as those involved in promoting organ size and others that restrict disproportionate tissue growth act simultaneously to maintain cellular and tissue homeostasis. Aberrations at any level in these organ size-regulating processes can lead to various pathological states with cancers being the most formidable one (Yin and Zhang, 2011). Extensive research in the realm of growth control has led to the identification of the Hippo-signaling pathway as a critical network in modulating tissue growth via its effect on multiple signaling pathways and through intricate crosstalk with proteins that regulate cell polarity, adhesion and cell-cell interactions (Zhao et al., 2011b). The Hippo pathway controls cell number and organ size by transducing signals from the plasma membrane to the nucleus to regulate the expression of genes involved in cell fate determination (Shi et al., 2015). In this review, we summarize the recent discoveries concerning Hippo pathway, its diversiform regulation in mammals as well as its implications in cancers, and highlight the possible role of oxidative stress in Hippo pathway regulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

An improved stereologic method for three-dimensional estimation of particle size distribution from observations in two dimensions and its application.

PubMed

Xu, Yi-Hua; Pitot, Henry C

2003-09-01

Single enzyme-altered hepatocytes; altered hepatic foci (AHF); and nodular lesions have been implicated, respectively in the processes of initiation, promotion, and progression in rodent hepatocarcinogenesis. Qualitative and quantitative analyses of such lesions have been utilized both to identify and to determine the potency of initiating, promoting, and progressor agents in rodent liver. Of a number of possible parameters determined in the study of such lesions, estimation of the number of foci or nodules in the liver is very important. The method of Saltykov has been used for estimating the number of AHF in rat liver. However, in practice, the Saltykov calculation has at least two weak points: (a) the size class range is limited to 12, which in many instances is too narrow to cover the range of AHF data obtained; and (b) under some conditions, the Saltykov equation generates negative values in several size classes, an obvious impossibility in the real world. In order to overcome these limitations in the Saltykov calculations, a study of the particle size distribution in a wide-range, polydispersed sphere system was performed. A stereologic method, termed the 25F Association method, was developed from this study. This method offers 25 association factors that are derived from the frequency of different-sized transections obtained from transecting a spherical particle, thus expanding the size class range to be analyzed up to 25, which is sufficiently wide to encompass all rat AHF found in most cases. This method exhibits greater flexibility, which allows adjustments to be made within the calculation process when NA((k,k)), the net number of transections from the same size spheres, was found to be a negative value, which is not possible in real situations. The reliability of the 25F Association method was tested thoroughly by computer simulation in both monodispersed and polydispersed sphere systems. The test results were compared with the original Saltykov method. We found that the 25F Association method yielded a better estimate of the total number of spheres in the three-dimensional tissue sample as well as the detailed size distribution information. Although the 25F Association method was derived from the study of a polydispersed sphere system, it can be used for continuous size distribution sphere systems. Application of this method to the estimation of parameters of preneoplastic foci in rodent liver is presented as an example of its utility. An application software program, 3D_estimation.exe, which uses the 25F Association method to estimate the number of AHF in rodent liver, has been developed and is now available at the website of this laboratory.

In-training factors predictive of choosing and sustaining a productive academic career path in neurological surgery.

PubMed

Crowley, R Webster; Asthagiri, Ashok R; Starke, Robert M; Zusman, Edie E; Chiocca, E Antonio; Lonser, Russell R

2012-04-01

Factors during neurosurgical residency that are predictive of an academic career path and promotion have not been defined. To determine factors associated with selecting and sustaining an academic career in neurosurgery by analyzing in-training factors for all graduates of American College of Graduate Medical Education (ACGME)-accredited programs between 1985 and 1990. Neurological surgery residency graduates (between 1985 and 1990) from ACGME-approved training programs were analyzed to determine factors associated with choosing an academic career path and having academic success. Information was available for 717 of the 720 (99%) neurological surgery resident training graduates (678 male, 39 female). One hundred thirty-eight graduates (19.3%) held full-time academic positions. One hundred seven (14.9%) were professors and 35 (4.9%) were department chairs/chiefs. An academic career path/success was associated with more total (5.1 vs 1.9; P < .001) and first-author publications (3.0 vs 1.0; P < .001) during residency. Promotion to professor or chair/chief was associated with more publications during residency (P < .001). Total publications and first-author publications were independent predictors of holding a current academic position and becoming professor or chair/chief. Although male trainees published more than female trainees (2.6 vs 0.9 publications; P < .004) during training, no significant sex difference was observed regarding current academic position. Program size (≥ 2 graduates a year; P = .02) was predictive of an academic career but not predictive of becoming professor or chair/chief (P > .05). Defined in-training factors including number of total publications, number of first-author publications, and program size are predictive of residents choosing and succeeding in an academic career path.

Religious Burning as a Major Source of Atmospheric Fine Aerosols in Lhasa city in the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Liu, S.; Cui, Y.; Zhixuan, B.; Bian, J.; McKeen, S. A.; Watts, L. A.; Ciciora, S. J.; Gao, R. S.

2017-12-01

Measurements of aerosols in the Tibetan Plateau are scant due to the high altitude and harsh climate. To bridge this gap, we carried out the first field measurements of aerosol size distributions in Lhasa, a major city in the Tibetan Plateau that has been experiencing fast urbanization and reduced air quality. Aerosol number size distribution was continuously measured using an optical particle size spectrometer near the center of Lhasa city during the Asian summer monsoon season in 2016. The mass concentration of fine particles was modulated by boundary layer dynamics, with an average of 11 µg m-3 and the high values exceeding 50 µg m-3 during religious holidays. Daytime high concentration coincided with the religious burning of biomass and incense in the temples during morning hours, which produced heavy smoke. Factor analysis revealed a factor that is likely induced by religious burning. The factor contributed 34% of the campaign-average fine particle mass and the contribution reached up to 80% during religious holidays. The mass size distribution of aerosols produced from religious burnings peaked at 500 nm, indicating that these particles could efficiently decrease visibility and promote health risk. Because of its significance, our results suggest that more attention should be paid to religious burning, a currently under-studied source, in the Tibetan Plateau and in other regions of the world where religious burnings are frequently practiced.

Population ecology of the mallard: II. Breeding habitat conditions, size of the breeding populations, and production indices

USGS Publications Warehouse

Pospahala, Richard S.; Anderson, David R.; Henny, Charles J.

1974-01-01

This report, the second in a series on a comprehensive analysis of mallard population data, provides information on mallard breeding habitat, the size and distribution of breeding populations, and indices to production. The information in this report is primarily the result of large-scale aerial surveys conducted during May and July, 1955-73. The history of the conflict in resource utilization between agriculturalists and wildlife conservation interests in the primary waterfowl breeding grounds is reviewed. The numbers of ponds present during the breeding season and the midsummer period and the effects of precipitation and temperature on the number of ponds present are analyzed in detail. No significant cycles in precipitation were detected and it appears that precipitation is primarily influenced by substantial seasonal and random components. Annual estimates (1955-73) of the number of mallards in surveyed and unsurveyed breeding areas provided estimates of the size and geographic distribution of breeding mallards in North America. The estimated size of the mallard breeding population in North America has ranged from a high of 14.4 million in 1958 to a low of 7.1 million in 1965. Generally, the mallard breeding population began to decline after the 1958 peak until 1962, and remained below 10 million birds until 1970. The decline and subsequent low level of the mallard population between 1959 and 1969 .generally coincided with a period of poor habitat conditions on the major breeding grounds. The density of mallards was highest in the Prairie-Parkland Area with an average of nearly 19.2 birds per square mile. The proportion of the continental mallard breeding population in the Prairie-Parkland Area ranged from 30% in 1962 to a high of 600/0 in 1956. The geographic distribution of breeding mallards throughout North America was significantly related to the number of May ponds in the Prairie-Parkland Area. Estimates of midsummer habitat conditions and indices to production from the July Production Survey were studied in detail. Several indices relating to production showed marked declines from west to east in the Prairie-Parkland Area, these are: (1) density of breeding mallards (per square mile and per May pond), (2) brood density (per square mile and per July pond), (3) average brood size (all species combined), and (4) brood survival from class II to class III. An index to late nesting and renesting efforts was highest during years when midsummer water conditions were good. Production rates of many ducks breeding in North America appear to be regulated by both density-dependent and density-independent factors. Spacing of birds in the Prairie-Parkland Area appeared to be a key factor in the density-dependent regulation of the population. The spacing mechanism, in conjunction with habitat conditions, influenced some birds to overfly the primary breeding grounds into less favorable habitats to the north and northwest where the production rate may be suppressed. The production rate of waterfowl in the Prairie Parkland Area seems to be independent of density (after emigration has taken place) because the production index appears to be a linear function of the number of breeding birds in the area. Similarly, the production rate of waterfowl in northern Saskatchewan and northern Manitoba appeared to be independent of density. Production indices in these northern areas appear to be a linear function of the size of the breeding population. Thus, the density and distribution of breeding ducks is probably regulated through a spacing mechanism that is at least partially dependent on measurable environmental factors. The result is a density-dependent process operating to ultimately effect the production and production rate of breeding ducks on a continent-wide basis. Continental production, and therefore the size of the fall population, is probably partially regulated by the number of birds that are distributed north and northwest into environments less favorable for successful reproduction. Thus, spacing of the birds in the Prairie-Parkland Area and the movement of a fraction of the birds out of the prime breeding areas may be key factors in the density-dependent regulation of the total mallard population.

The assessment of biases in the acoustic discrimination of individuals

PubMed Central

Šálek, Martin

2017-01-01

Animal vocalizations contain information about individual identity that could potentially be used for the monitoring of individuals. However, the performance of individual discrimination is subjected to many biases depending on factors such as the amount of identity information, or methods used. These factors need to be taken into account when comparing results of different studies or selecting the most cost-effective solution for a particular species. In this study, we evaluate several biases associated with the discrimination of individuals. On a large sample of little owl male individuals, we assess how discrimination performance changes with methods of call description, an increasing number of individuals, and number of calls per male. Also, we test whether the discrimination performance within the whole population can be reliably estimated from a subsample of individuals in a pre-screening study. Assessment of discrimination performance at the level of the individual and at the level of call led to different conclusions. Hence, studies interested in individual discrimination should optimize methods at the level of individuals. The description of calls by their frequency modulation leads to the best discrimination performance. In agreement with our expectations, discrimination performance decreased with population size. Increasing the number of calls per individual linearly increased the discrimination of individuals (but not the discrimination of calls), likely because it allows distinction between individuals with very similar calls. The available pre-screening index does not allow precise estimation of the population size that could be reliably monitored. Overall, projects applying acoustic monitoring at the individual level in population need to consider limitations regarding the population size that can be reliably monitored and fine-tune their methods according to their needs and limitations. PMID:28486488

Environmental factors affecting benthic macrofauna along a gradient of intermediate sandy beaches in northern Spain

NASA Astrophysics Data System (ADS)

Rodil, I. F.; Lastra, M.

2004-09-01

Ten sandy beaches along the north coast of Spain were studied during September 1999 to analyse the number of species, abundance and biomass of macroinfauna along a gradient of intermediate beach types and exposure range. Faunal samples were collected with metallic cylinders (25 cm diameter, 15 cm depth) at 10 equally spaced shore levels along six replicated transects separated randomly and extending from above the drift line to the low tide swash zone. Exposure rate, Dean's parameter ( Ω), beach state index (BSI) and relative tidal range (RTR) were estimated at each beach. Length and width of the beach, intertidal slope, sorting and median grain size and also swash amplitude and wave characteristics were measured. The number of species was between 10 and 29. Macrofaunal abundances ranged between 4962 and 71,228 ind. linear m -1 and between 31 and 329 ind. m -2, while biomass (ash free dry weight) ranged between 0.027 and 0.278 g m -2 and between 3 and 61 g linear m -1. The results show some significant trends: the number of species is the biotic variable most affected by physical and morphodynamic factors, increasing linearly with relative tidal range and decreasing with increasing average grain size. The same trend was observed from exposed to very exposed beaches and the biomass decreased exponentially with increasing average grain size. These trends agree with previous studies in different coasts in the world where coarse sands limit the benthic macrofauna. The morphodynamic parameters as Dean's parameter or Beach State Index did not show a predictive value. The results suggest that different characteristics of benthic macrofauna communities in intermediate beaches can be affected in different ways by the physical processes involved in beach morphodynamics.

Factors influencing particle number concentrations, size distributions and modal parameters at a roof-level and roadside site in Leicester, UK.

PubMed

Agus, Emily L; Young, David T; Lingard, Justin J N; Smalley, Robert J; Tate, James E; Goodman, Paul S; Tomlin, Alison S

2007-11-01

Measurements of urban particle number concentrations and size distributions in the range 5-1000 nm were taken at elevated (roof-level) and roadside sampling sites on Narborough Road in Leicester, UK, along with simultaneous measurements of traffic, NO(x), CO and 1,3-butadiene concentrations and meteorological parameters. A fitting program was used to determine the characteristics of up to five modal groups present in the particle size distributions. All particle modal concentrations peaked during the morning and evening rush hours. Additional events associated with the smallest mode, that were not observed to be connected to primary emissions, were also present suggesting that this mode consisted of newly formed secondary particles. These events included peaks in concentration which coincided with peaks in solar radiation, and lower concentrations of the larger modes. Investigation into the relationships between traffic flow and occupancy indicated three flow regimes; free-flow, unstable and congested. During free-flow conditions, positive linear relationships existed between traffic flow and particle modal number concentrations. However, during unstable and congested periods, this relationship was shown to break-down. Similar trends were observed for concentrations of the gas phase pollutants NO(x), CO and 1,3-butadiene. Strong linear relationships existed between NO(x), CO, 1,3-butadiene concentrations, nucleation and Aitken mode concentrations at both sampling locations, indicating a local traffic related emission source. At the roadside, both nucleation and Aitken mode are best represented by a decreasing exponential function with wind speed, whereas at the roof-level this relationship only occurred for Aitken mode particles. The differing relationships at the two sampling locations are most likely due to a combination of meteorological factors and distance from the local emission source.

An algorithm for fast elastic wave simulation using a vectorized finite difference operator

NASA Astrophysics Data System (ADS)

Malkoti, Ajay; Vedanti, Nimisha; Tiwari, Ram Krishna

2018-07-01

Modern geophysical imaging techniques exploit the full wavefield information which can be simulated numerically. These numerical simulations are computationally expensive due to several factors, such as a large number of time steps and nodes, big size of the derivative stencil and huge model size. Besides these constraints, it is also important to reformulate the numerical derivative operator for improved efficiency. In this paper, we have introduced a vectorized derivative operator over the staggered grid with shifted coordinate systems. The operator increases the efficiency of simulation by exploiting the fact that each variable can be represented in the form of a matrix. This operator allows updating all nodes of a variable defined on the staggered grid, in a manner similar to the collocated grid scheme and thereby reducing the computational run-time considerably. Here we demonstrate an application of this operator to simulate the seismic wave propagation in elastic media (Marmousi model), by discretizing the equations on a staggered grid. We have compared the performance of this operator on three programming languages, which reveals that it can increase the execution speed by a factor of at least 2-3 times for FORTRAN and MATLAB; and nearly 100 times for Python. We have further carried out various tests in MATLAB to analyze the effect of model size and the number of time steps on total simulation run-time. We find that there is an additional, though small, computational overhead for each step and it depends on total number of time steps used in the simulation. A MATLAB code package, 'FDwave', for the proposed simulation scheme is available upon request.

Metastatic Lymph Node Burden and Survival in Oral Cavity Cancer

PubMed Central

Kim, Sungjin; Tighiouart, Mourad; Gudino, Cynthia; Mita, Alain; Scher, Kevin S.; Laury, Anna; Prasad, Ravi; Shiao, Stephen L.; Van Eyk, Jennifer E.; Zumsteg, Zachary S.

2017-01-01

Purpose Current staging systems for oral cavity cancers incorporate lymph node (LN) size and laterality, but place less weight on the total number of positive metastatic nodes. We investigated the independent impact of numerical metastatic LN burden on survival. Methods Adult patients with oral cavity squamous cell carcinoma undergoing upfront surgical resection for curative intent were identified in the National Cancer Data Base between 2004 and 2013. A neck dissection of a minimum of 10 LNs was required. Multivariable models were constructed to assess the association between the number of metastatic LNs and survival, adjusting for factors such as nodal size, laterality, extranodal extension, margin status, and adjuvant treatment. Results Overall, 14,554 patients met inclusion criteria (7,906 N0 patients; 6,648 node-positive patients). Mortality risk escalated continuously with increasing number of metastatic nodes without plateau, with the effect most pronounced with up to four LNs (HR, 1.34; 95% CI, 1.29 to 1.39; P < .001). Extranodal extension (HR, 1.41; 95% CI, 1.20 to 1.65; P < .001) and lower neck involvement (HR, 1.16; 95% CI, 1.06 to 1.27; P < .001) also predicted increased mortality. Increasing number of nodes examined was associated with improved survival, plateauing at 35 LNs (HR, 0.98; 95% CI, 0.98 to 0.99; P < .001). In multivariable models accounting for the number of metastatic nodes, contralateral LN involvement (N2c status) and LN size were not associated with mortality. A novel nodal staging system derived by recursive partitioning analysis exhibited greater concordance than the American Joint Committee on Cancer (8th edition) system. Conclusion The number of metastatic nodes is a critical predictor of oral cavity cancer mortality, eclipsing other features such as LN size and contralaterality in prognostic value. More robust incorporation of numerical metastatic LN burden may augment staging and better inform adjuvant treatment decisions. PMID:28880746

Optimal reproduction in salmon spawning substrates linked to grain size and fish length

NASA Astrophysics Data System (ADS)

Riebe, Clifford S.; Sklar, Leonard S.; Overstreet, Brandon T.; Wooster, John K.

2014-02-01

Millions of dollars are spent annually on revitalizing salmon spawning in riverbeds where redd building by female salmon is inhibited by sediment that is too big for fish to move. Yet the conditions necessary for productive spawning remain unclear. There is no gauge for quantifying how grain size influences the reproductive potential of coarse-bedded rivers. Hence, managers lack a quantitative basis for optimizing spawning habitat restoration for reproductive value. To overcome this limitation, we studied spawning by Chinook, sockeye, and pink salmon (Oncorhynchus tshawytscha, O. nerka, and O. gorbuscha) in creeks and rivers of California and the Pacific Northwest. Our analysis shows that coarse substrates have been substantially undervalued as spawning habitat in previous work. We present a field-calibrated approach for estimating the number of redds and eggs a substrate can accommodate from measurements of grain size and fish length. Bigger fish can move larger sediment and thus use more riverbed area for spawning. They also tend to have higher fecundity, and so can deposit more eggs per redd. However, because redd area increases with fish length, the number of eggs a substrate can accommodate is maximized for moderate-sized fish. This previously unrecognized tradeoff raises the possibility that differences in grain size help regulate river-to-river differences in salmon size. Thus, population diversity and species resilience may be linked to lithologic, geomorphic, and climatic factors that determine grain size in rivers. Our approach provides a tool for managing grain-size distributions in support of optimal reproductive potential and species resilience.

Understanding the effect of lactose particle size on the properties of DPI formulations using experimental design.

PubMed

Guenette, Estelle; Barrett, Andrew; Kraus, Debbie; Brody, Rachel; Harding, Ljiljana; Magee, Gavin

2009-10-01

Medicines for delivering therapeutic agents to the lung as dry powders primarily consist of a carrier and a micronised active pharmaceutical ingredient (API). The performance of an inhaled formulation will depend on a number of factors amongst which the particle size distribution (PSD) plays a key role. It is suggested that increasing the number of fine particles in the carrier can improve the aerosolisation of the API. In addition the effect of PSD upon a bulk powder is also broadly understood in terms of powder flow. Other aspects of functionality that different size fractions of the carrier affect are not clearly understood; for example, it is not yet clearly known how different size fractions contribute to the different functionalities of the carrier. It is the purpose of this investigation to examine the effects of different lactose size fractions on fine particle dose, formulation stability and the ability to process and fill the material in the preferred device. In order to understand the true impact of the size fractions of lactose on the performance of dry powder inhaled (DPI) products, a statistically designed study has been conducted. The study comprised various DPI blend formulations prepared using lactose monohydrate carrier systems consisting of mixtures of four size fractions. Interactive mixtures were prepared containing 1% (w/w) salbutamol sulphate. The experimental design enabled the evaluation of the effect of lactose size fractions on processing and performance attributes of the formulation. Furthermore, the results of the study demonstrate that an experimental design approach can be used successfully to support dry powder formulation development.

Characterization of an in vivo diode dosimetry system for clinical use

PubMed Central

Huang, Kai; Bice, William S.; Hidalgo‐Salvatierra, Oscar

2003-01-01

An in vivo dosimetry system that uses p‐type semiconductor diodes with buildup caps was characterized for clinical use on accelerators ranging in energy from 4 to 18 MV. The dose per pulse dependence was investigated. This was done by altering the source‐surface distance, field size, and wedge for photons. The off‐axis correction and effect of changing repetition rate were also investigated. A model was developed to fit the measured two‐dimensional diode correction factors. PACS number(s): 87.66.–a, 87.52.–g PMID:12777148

Early risk and protective factors for problem gambling: A systematic review and meta-analysis of longitudinal studies.

PubMed

Dowling, N A; Merkouris, S S; Greenwood, C J; Oldenhof, E; Toumbourou, J W; Youssef, G J

2017-02-01

This systematic review aimed to identify early risk and protective factors (in childhood, adolescence or young adulthood) longitudinally associated with the subsequent development of gambling problems. A systematic search of peer-reviewed and grey literature from 1990 to 2015 identified 15 studies published in 23 articles. Meta-analyses quantified the effect size of 13 individual risk factors (alcohol use frequency, antisocial behaviours, depression, male gender, cannabis use, illicit drug use, impulsivity, number of gambling activities, problem gambling severity, sensation seeking, tobacco use, violence, undercontrolled temperament), one relationship risk factor (peer antisocial behaviours), one community risk factor (poor academic performance), one individual protective factor (socio-economic status) and two relationship protective factors (parent supervision, social problems). Effect sizes were on average small to medium and sensitivity analyses revealed that the results were generally robust to the quality of methodological approaches of the included articles. These findings highlight the need for global prevention efforts that reduce risk factors and screen young people with high-risk profiles. There is insufficient investigation of protective factors to adequately guide prevention initiatives. Future longitudinal research is required to identify additional risk and protective factors associated with problem gambling, particularly within the relationship, community, and societal levels of the socio-ecological model. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Allee effect in the selection for prime-numbered cycles in periodical cicadas.

PubMed

Tanaka, Yumi; Yoshimura, Jin; Simon, Chris; Cooley, John R; Tainaka, Kei-ichi

2009-06-02

Periodical cicadas are well known for their prime-numbered life cycles (17 and 13 years) and their mass periodical emergences. The origination and persistence of prime-numbered cycles are explained by the hybridization hypothesis on the basis of their lower likelihood of hybridization with other cycles. Recently, we showed by using an integer-based numerical model that prime-numbered cycles are indeed selected for among 10- to 20-year cycles. Here, we develop a real-number-based model to investigate the factors affecting the selection of prime-numbered cycles. We include an Allee effect in our model, such that a critical population size is set as an extinction threshold. We compare the real-number models with and without the Allee effect. The results show that in the presence of an Allee effect, prime-numbered life cycles are most likely to persist and to be selected under a wide range of extinction thresholds.

The structure factor of primes

NASA Astrophysics Data System (ADS)

Zhang, G.; Martelli, F.; Torquato, S.

2018-03-01

Although the prime numbers are deterministic, they can be viewed, by some measures, as pseudo-random numbers. In this article, we numerically study the pair statistics of the primes using statistical-mechanical methods, particularly the structure factor S(k) in an interval M ≤slant p ≤slant M + L with M large, and L/M smaller than unity. We show that the structure factor of the prime-number configurations in such intervals exhibits well-defined Bragg-like peaks along with a small ‘diffuse’ contribution. This indicates that primes are appreciably more correlated and ordered than previously thought. Our numerical results definitively suggest an explicit formula for the locations and heights of the peaks. This formula predicts infinitely many peaks in any non-zero interval, similar to the behavior of quasicrystals. However, primes differ from quasicrystals in that the ratio between the location of any two predicted peaks is rational. We also show numerically that the diffuse part decays slowly as M and L increases. This suggests that the diffuse part vanishes in an appropriate infinite-system-size limit.

Amyloplast Membrane Protein SUBSTANDARD STARCH GRAIN6 Controls Starch Grain Size in Rice Endosperm1

PubMed Central

Matsushima, Ryo; Maekawa, Masahiko; Kusano, Miyako; Tomita, Katsura; Kondo, Hideki; Nishimura, Hideki; Crofts, Naoko; Fujita, Naoko; Sakamoto, Wataru

2016-01-01

Starch is a biologically and commercially important polymer of glucose. Starch is organized into starch grains (SGs) inside amyloplasts. The SG size differs depending on the plant species and is one of the most important factors for industrial applications of starch. There is limited information on genetic factors regulating SG sizes. In this study, we report the rice (Oryza sativa) mutant substandard starch grain6 (ssg6), which develops enlarged SGs in endosperm. Enlarged SGs are observed starting at 3 d after flowering. During endosperm development, a number of smaller SGs appear and coexist with enlarged SGs in the same cells. The ssg6 mutation also affects SG morphologies in pollen. The SSG6 gene was identified by map-based cloning and microarray analysis. SSG6 encodes a protein homologous to aminotransferase. SSG6 differs from other rice homologs in that it has a transmembrane domain. SSG6-green fluorescent protein is localized in the amyloplast membrane surrounding SGs in rice endosperm, pollen, and pericarp. The results of this study suggest that SSG6 is a novel protein that controls SG size. SSG6 will be a useful molecular tool for future starch breeding and applications. PMID:26792122

Predisposing Factors of Liver Necrosis after Transcatheter Arterial Chemoembolization in Liver Metastases from Neuroendocrine Tumor

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

Joskin, Julien, E-mail: j.joskin@gmail.com; Baere, Thierry de, E-mail: Thierry.DEBAERE@igr.fr; Auperin, Anne, E-mail: Anne.AUPERIN@igr.fr

PurposeTo investigate predictive factors for liver necrosis after transcatheter arterial chemoembolization (TACE) of neuroendocrine liver metastases.MethodsA total of 164 patients receiving 374 TACE were reviewed retrospectively to analyze predictive factors of liver necrosis. We analyzed patient age and sex; metastasis number and location; percentage of liver involvement; baseline liver function test; and pretreatment imaging abnormalities such as bile duct dilatation (BDD), portal vein narrowing (PVN), and portal vein thrombosis (PVT). We analyzed TACE technique such as Lipiodol or drug-eluting beads (DEB) as the drug’s vector; dose of chemotherapy; diameter of DEB; and number, frequency, and selectivity of TACE.ResultsLiver necrosis developedmore » after 23 (6.1 %) of 374 TACE. In multivariate analysis, DEB > 300 μm in size induced more liver necrosis compared to Lipiodol (odds ratio [OR] 35.20; p < 0.0001) or with DEB < 300 μm in size (OR 19.95; p < 0.010). Pretreatment BDD (OR 119.64; p < 0.0001) and PVT (OR 9.83; p = 0.030) were predictive of liver necrosis. BDD or PVT responsible for liver necrosis were present before TACE in 59 % (13 of 22) and were induced by a previous TACE in 41 % (9 of 22) of cases.ConclusionDEB > 300 μm in size, BDD, and PVT are responsible for increased rate of liver necrosis after TACE. Careful analysis of BDD or PVT on pretreatment images as well as images taken between two courses can help avoid TACE complications.« less

A comparison of facial expression properties in five hylobatid species.

PubMed

Scheider, Linda; Liebal, Katja; Oña, Leonardo; Burrows, Anne; Waller, Bridget

2014-07-01

Little is known about facial communication of lesser apes (family Hylobatidae) and how their facial expressions (and use of) relate to social organization. We investigated facial expressions (defined as combinations of facial movements) in social interactions of mated pairs in five different hylobatid species belonging to three different genera using a recently developed objective coding system, the Facial Action Coding System for hylobatid species (GibbonFACS). We described three important properties of their facial expressions and compared them between genera. First, we compared the rate of facial expressions, which was defined as the number of facial expressions per units of time. Second, we compared their repertoire size, defined as the number of different types of facial expressions used, independent of their frequency. Third, we compared the diversity of expression, defined as the repertoire weighted by the rate of use for each type of facial expression. We observed a higher rate and diversity of facial expression, but no larger repertoire, in Symphalangus (siamangs) compared to Hylobates and Nomascus species. In line with previous research, these results suggest siamangs differ from other hylobatids in certain aspects of their social behavior. To investigate whether differences in facial expressions are linked to hylobatid socio-ecology, we used a Phylogenetic General Least Square (PGLS) regression analysis to correlate those properties with two social factors: group-size and level of monogamy. No relationship between the properties of facial expressions and these socio-ecological factors was found. One explanation could be that facial expressions in hylobatid species are subject to phylogenetic inertia and do not differ sufficiently between species to reveal correlations with factors such as group size and monogamy level. © 2014 Wiley Periodicals, Inc.

Methodological reporting of randomized clinical trials in respiratory research in 2010.

PubMed

Lu, Yi; Yao, Qiuju; Gu, Jie; Shen, Ce

2013-09-01

Although randomized controlled trials (RCTs) are considered the highest level of evidence, they are also subject to bias, due to a lack of adequately reported randomization, and therefore the reporting should be as explicit as possible for readers to determine the significance of the contents. We evaluated the methodological quality of RCTs in respiratory research in high ranking clinical journals, published in 2010. We assessed the methodological quality, including generation of the allocation sequence, allocation concealment, double-blinding, sample-size calculation, intention-to-treat analysis, flow diagrams, number of medical centers involved, diseases, funding sources, types of interventions, trial registration, number of times the papers have been cited, journal impact factor, journal type, and journal endorsement of the CONSORT (Consolidated Standards of Reporting Trials) rules, in RCTs published in 12 top ranking clinical respiratory journals and 5 top ranking general medical journals. We included 176 trials, of which 93 (53%) reported adequate generation of the allocation sequence, 66 (38%) reported adequate allocation concealment, 79 (45%) were double-blind, 123 (70%) reported adequate sample-size calculation, 88 (50%) reported intention-to-treat analysis, and 122 (69%) included a flow diagram. Multivariate logistic regression analysis revealed that journal impact factor ≥ 5 was the only variable that significantly influenced adequate allocation sequence generation. Trial registration and journal impact factor ≥ 5 significantly influenced adequate allocation concealment. Medical interventions, trial registration, and journal endorsement of the CONSORT statement influenced adequate double-blinding. Publication in one of the general medical journal influenced adequate sample-size calculation. The methodological quality of RCTs in respiratory research needs improvement. Stricter enforcement of the CONSORT statement should enhance the quality of RCTs.

Small, medium, large or supersize? The development and evaluation of interventions targeted at portion size

PubMed Central

Vermeer, W M; Steenhuis, I H M; Poelman, M P

2014-01-01

In the past decades, portion sizes of high-caloric foods and drinks have increased and can be considered an important environmental obesogenic factor. This paper describes a research project in which the feasibility and effectiveness of environmental interventions targeted at portion size was evaluated. The studies that we conducted revealed that portion size labeling, offering a larger variety of portion sizes, and proportional pricing (that is, a comparable price per unit regardless of the size) were considered feasible to implement according to both consumers and point-of-purchase representatives. Studies into the effectiveness of these interventions demonstrated that the impact of portion size labeling on the (intended) consumption of soft drinks was, at most, modest. Furthermore, the introduction of smaller portion sizes of hot meals in worksite cafeterias in addition to the existing size stimulated a moderate number of consumers to replace their large meals by a small meal. Elaborating on these findings, we advocate further research into communication and marketing strategies related to portion size interventions; the development of environmental portion size interventions as well as educational interventions that improve people's ability to deal with a ‘super-sized' environment; the implementation of regulation with respect to portion size labeling, and the use of nudges to stimulate consumers to select healthier portion sizes. PMID:25033959

Size-dependent selective mechanisms on males and females and the evolution of sexual size dimorphism in frogs.

PubMed

Nali, Renato C; Zamudio, Kelly R; Haddad, Célio F B; Prado, Cynthia P A

2014-12-01

Sexual size dimorphism (SSD) varies in animals from male biased to female biased. The evolution of SSD is potentially influenced by a number of factors, such as territoriality, fecundity, and temporal breeding patterns (explosive vs. prolonged). In general, frogs show female-biased SSD with broad variance among species. Using comparative methods, we examine how different selective forces affect male and female sizes, and we test hypotheses about size-dependent mechanisms shaping SSD in frogs. Male size was weakly associated with SSD in all size classes, and we found no significant association among SSD, male size, temporal breeding pattern, and male territoriality. In contrast, female size best explained SSD variation across all size classes but especially for small-bodied species. We found a stronger evolutionary association between female body size and fecundity, and this fecundity advantage was highest in explosively breeding species. Our data indicate that the fecundity advantage associated with female body size may not be linear, such that intermediate and large females benefit less with body size increases. Therefore, size-dependent selection in females associated with fecundity and breeding patterns is an important mechanism driving SSD evolution in frogs. Our study underscores the fact that lineage-specific ecology and behavior should be incorporated in comparative analyses of animal SSD.

Small, medium, large or supersize? The development and evaluation of interventions targeted at portion size.

PubMed

Vermeer, W M; Steenhuis, I H M; Poelman, M P

2014-07-01

In the past decades, portion sizes of high-caloric foods and drinks have increased and can be considered an important environmental obesogenic factor. This paper describes a research project in which the feasibility and effectiveness of environmental interventions targeted at portion size was evaluated. The studies that we conducted revealed that portion size labeling, offering a larger variety of portion sizes, and proportional pricing (that is, a comparable price per unit regardless of the size) were considered feasible to implement according to both consumers and point-of-purchase representatives. Studies into the effectiveness of these interventions demonstrated that the impact of portion size labeling on the (intended) consumption of soft drinks was, at most, modest. Furthermore, the introduction of smaller portion sizes of hot meals in worksite cafeterias in addition to the existing size stimulated a moderate number of consumers to replace their large meals by a small meal. Elaborating on these findings, we advocate further research into communication and marketing strategies related to portion size interventions; the development of environmental portion size interventions as well as educational interventions that improve people's ability to deal with a 'super-sized' environment; the implementation of regulation with respect to portion size labeling, and the use of nudges to stimulate consumers to select healthier portion sizes.

Long-term cloud condensation nuclei number concentration, particle number size distribution and chemical composition measurements at regionally representative observatories

NASA Astrophysics Data System (ADS)

Schmale, Julia; Henning, Silvia; Decesari, Stefano; Henzing, Bas; Keskinen, Helmi; Sellegri, Karine; Ovadnevaite, Jurgita; Pöhlker, Mira L.; Brito, Joel; Bougiatioti, Aikaterini; Kristensson, Adam; Kalivitis, Nikos; Stavroulas, Iasonas; Carbone, Samara; Jefferson, Anne; Park, Minsu; Schlag, Patrick; Iwamoto, Yoko; Aalto, Pasi; Äijälä, Mikko; Bukowiecki, Nicolas; Ehn, Mikael; Frank, Göran; Fröhlich, Roman; Frumau, Arnoud; Herrmann, Erik; Herrmann, Hartmut; Holzinger, Rupert; Kos, Gerard; Kulmala, Markku; Mihalopoulos, Nikolaos; Nenes, Athanasios; O'Dowd, Colin; Petäjä, Tuukka; Picard, David; Pöhlker, Christopher; Pöschl, Ulrich; Poulain, Laurent; Prévôt, André Stephan Henry; Swietlicki, Erik; Andreae, Meinrat O.; Artaxo, Paulo; Wiedensohler, Alfred; Ogren, John; Matsuki, Atsushi; Yum, Seong Soo; Stratmann, Frank; Baltensperger, Urs; Gysel, Martin

2018-02-01

Aerosol-cloud interactions (ACI) constitute the single largest uncertainty in anthropogenic radiative forcing. To reduce the uncertainties and gain more confidence in the simulation of ACI, models need to be evaluated against observations, in particular against measurements of cloud condensation nuclei (CCN). Here we present a data set - ready to be used for model validation - of long-term observations of CCN number concentrations, particle number size distributions and chemical composition from 12 sites on 3 continents. Studied environments include coastal background, rural background, alpine sites, remote forests and an urban surrounding. Expectedly, CCN characteristics are highly variable across site categories. However, they also vary within them, most strongly in the coastal background group, where CCN number concentrations can vary by up to a factor of 30 within one season. In terms of particle activation behaviour, most continental stations exhibit very similar activation ratios (relative to particles > 20 nm) across the range of 0.1 to 1.0 % supersaturation. At the coastal sites the transition from particles being CCN inactive to becoming CCN active occurs over a wider range of the supersaturation spectrum. Several stations show strong seasonal cycles of CCN number concentrations and particle number size distributions, e.g. at Barrow (Arctic haze in spring), at the alpine stations (stronger influence of polluted boundary layer air masses in summer), the rain forest (wet and dry season) or Finokalia (wildfire influence in autumn). The rural background and urban sites exhibit relatively little variability throughout the year, while short-term variability can be high especially at the urban site. The average hygroscopicity parameter, κ, calculated from the chemical composition of submicron particles was highest at the coastal site of Mace Head (0.6) and lowest at the rain forest station ATTO (0.2-0.3). We performed closure studies based on κ-Köhler theory to predict CCN number concentrations. The ratio of predicted to measured CCN concentrations is between 0.87 and 1.4 for five different types of κ. The temporal variability is also well captured, with Pearson correlation coefficients exceeding 0.87. Information on CCN number concentrations at many locations is important to better characterise ACI and their radiative forcing. But long-term comprehensive aerosol particle characterisations are labour intensive and costly. Hence, we recommend operating migrating-CCNCs to conduct collocated CCN number concentration and particle number size distribution measurements at individual locations throughout one year at least to derive a seasonally resolved hygroscopicity parameter. This way, CCN number concentrations can only be calculated based on continued particle number size distribution information and greater spatial coverage of long-term measurements can be achieved.

Identifying maternal and infant factors associated with newborn size in rural Bangladesh by partial least squares (PLS) regression analysis

PubMed Central

Rahman, Md. Jahanur; Shamim, Abu Ahmed; Klemm, Rolf D. W.; Labrique, Alain B.; Rashid, Mahbubur; Christian, Parul; West, Keith P.

2017-01-01

Birth weight, length and circumferences of the head, chest and arm are key measures of newborn size and health in developing countries. We assessed maternal socio-demographic factors associated with multiple measures of newborn size in a large rural population in Bangladesh using partial least squares (PLS) regression method. PLS regression, combining features from principal component analysis and multiple linear regression, is a multivariate technique with an ability to handle multicollinearity while simultaneously handling multiple dependent variables. We analyzed maternal and infant data from singletons (n = 14,506) born during a double-masked, cluster-randomized, placebo-controlled maternal vitamin A or β-carotene supplementation trial in rural northwest Bangladesh. PLS regression results identified numerous maternal factors (parity, age, early pregnancy MUAC, living standard index, years of education, number of antenatal care visits, preterm delivery and infant sex) significantly (p<0.001) associated with newborn size. Among them, preterm delivery had the largest negative influence on newborn size (Standardized β = -0.29 − -0.19; p<0.001). Scatter plots of the scores of first two PLS components also revealed an interaction between newborn sex and preterm delivery on birth size. PLS regression was found to be more parsimonious than both ordinary least squares regression and principal component regression. It also provided more stable estimates than the ordinary least squares regression and provided the effect measure of the covariates with greater accuracy as it accounts for the correlation among the covariates and outcomes. Therefore, PLS regression is recommended when either there are multiple outcome measurements in the same study, or the covariates are correlated, or both situations exist in a dataset. PMID:29261760

Identifying maternal and infant factors associated with newborn size in rural Bangladesh by partial least squares (PLS) regression analysis.

PubMed

Kabir, Alamgir; Rahman, Md Jahanur; Shamim, Abu Ahmed; Klemm, Rolf D W; Labrique, Alain B; Rashid, Mahbubur; Christian, Parul; West, Keith P

2017-01-01

Birth weight, length and circumferences of the head, chest and arm are key measures of newborn size and health in developing countries. We assessed maternal socio-demographic factors associated with multiple measures of newborn size in a large rural population in Bangladesh using partial least squares (PLS) regression method. PLS regression, combining features from principal component analysis and multiple linear regression, is a multivariate technique with an ability to handle multicollinearity while simultaneously handling multiple dependent variables. We analyzed maternal and infant data from singletons (n = 14,506) born during a double-masked, cluster-randomized, placebo-controlled maternal vitamin A or β-carotene supplementation trial in rural northwest Bangladesh. PLS regression results identified numerous maternal factors (parity, age, early pregnancy MUAC, living standard index, years of education, number of antenatal care visits, preterm delivery and infant sex) significantly (p<0.001) associated with newborn size. Among them, preterm delivery had the largest negative influence on newborn size (Standardized β = -0.29 - -0.19; p<0.001). Scatter plots of the scores of first two PLS components also revealed an interaction between newborn sex and preterm delivery on birth size. PLS regression was found to be more parsimonious than both ordinary least squares regression and principal component regression. It also provided more stable estimates than the ordinary least squares regression and provided the effect measure of the covariates with greater accuracy as it accounts for the correlation among the covariates and outcomes. Therefore, PLS regression is recommended when either there are multiple outcome measurements in the same study, or the covariates are correlated, or both situations exist in a dataset.

No evidence of trade-offs in the evolution of sperm numbers and sperm size in mammals.

PubMed

Tourmente, M; Delbarco Trillo, J; Roldan, E R S

2015-10-01

Post-copulatory sexual selection, in the form sperm competition, has influenced the evolution of several male reproductive traits. However, theory predicts that sperm competition would lead to trade-offs between numbers and size of spermatozoa because increased costs per cell would result in a reduction of sperm number if both traits share the same energetic budget. Theoretical models have proposed that, in large animals, increased sperm size would have minimal fitness advantage compared with increased sperm numbers. Thus, sperm numbers would evolve more rapidly than sperm size under sperm competition pressure. We tested in mammals whether sperm competition maximizes sperm numbers and size, and whether there is a trade-off between these traits. Our results showed that sperm competition maximizes sperm numbers in eutherian and metatherian mammals. There was no evidence of a trade-off between sperm numbers and sperm size in any of the two mammalian clades as we did not observe any significant relationship between sperm numbers and sperm size once the effect of sperm competition was taken into account. Maximization of both numbers and size in mammals may occur because each trait is crucial at different stages in sperm's life; for example size-determined sperm velocity is a key determinant of fertilization success. In addition, numbers and size may also be influenced by diverse energetic budgets required at different stages of sperm formation. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Common factor analysis versus principal component analysis: choice for symptom cluster research.

PubMed

Kim, Hee-Ju

2008-03-01

The purpose of this paper is to examine differences between two factor analytical methods and their relevance for symptom cluster research: common factor analysis (CFA) versus principal component analysis (PCA). Literature was critically reviewed to elucidate the differences between CFA and PCA. A secondary analysis (N = 84) was utilized to show the actual result differences from the two methods. CFA analyzes only the reliable common variance of data, while PCA analyzes all the variance of data. An underlying hypothetical process or construct is involved in CFA but not in PCA. PCA tends to increase factor loadings especially in a study with a small number of variables and/or low estimated communality. Thus, PCA is not appropriate for examining the structure of data. If the study purpose is to explain correlations among variables and to examine the structure of the data (this is usual for most cases in symptom cluster research), CFA provides a more accurate result. If the purpose of a study is to summarize data with a smaller number of variables, PCA is the choice. PCA can also be used as an initial step in CFA because it provides information regarding the maximum number and nature of factors. In using factor analysis for symptom cluster research, several issues need to be considered, including subjectivity of solution, sample size, symptom selection, and level of measure.

[Rating and ranking of medical journals: a randomised controlled evaluation of impact factor and number of listed journals].

PubMed

Göbel, U; Niem, V

2012-01-01

The impact factor is a purely bibliometric parameter built on a number of publications and their citations that occur within clearly defined periods. Appropriate interpretation of the impact factor is important as it is also used worldwide for the evaluation of research performance. It is assumed that the number of medical journals reflects the extent of diseases and patient populations involved and that the number is correlated with the level of the impact factor. 174 category lists (Subject Categories) are included in the area Health Sciences of the ISI Web of Knowledge of Thomson Reuters, 71 of which belong to the field of medicine and 50 of which have a clinical and/or application-oriented focus. These alphabetically arranged 50 category lists were consecutively numbered, randomized by odd and even numbers, respectively, into 2 equal-sized groups and then grouped according to organ specialities, sub-specialities and cross-disciplinary fields. By tossing up a coin it was decided which group should be evaluated first. Only then the category lists were downloaded and the number of journals, as well as the impact factors of journals ranking number 1 and 2, as well as the impact factors of journals at the end of the first third and at the end of the first half of each category list were compared. The number of journals per category list varies considerably between 5 and 252. The lists of organ specialties and cross-disciplinary fields include more than three times as many journals as those of the sub-specialities; the highest numbers of journals are listed for the cross-disciplinary fields. The level of impact factor of journals that rank number 1 in the lists varies considerably and ranges from 3,058 to 94,333; a similar variability exists for the journals at rank 2. On the other hand, the impact factor of journals at the end of the first third of the lists varies from 1,214 and 3,953, and for those journals at the end of the first half of a respective category list it varies from 0,609 and 2,872. The slope of the straight correlation line between the level of impact factors of journals at rank 1 and 2 with the number of listed journals varies from 0,0756 and 0,2651 (correlation coefficients between 0,49 and 0,96). For the journals ranking further down in the lists the straight correlation lines run almost horizontally or with inverse slope. This current analysis adds to the knowledge for an appropriate interpretation of the impact factor. Generally, greater importance should be given to the ranking of a journal within a corresponding category list. © Georg Thieme Verlag KG Stuttgart · New York.

Numerical analysis of a dielectrophoresis field-flow fractionation device for the separation of multiple cell types.

PubMed

Shamloo, Amir; Kamali, Ali

2017-10-01

In this study, a dielectrophoresis field-flow fractionation device was analyzed using a numerical simulation method and the behaviors of a set of different cells were investigated. By reducing the alternating current frequency of the electrodes from the value used in the original setup configuration and increasing the number of exit channels, total discrimination in cell trajectories and subsequent separation of four cell types were achieved. Cells were differentiated based on their size and dielectric response that are represented in their real part of Clausius-Mossotti factor at different frequencies. A number of novel designs were also proposed based on the original setup configuration. It was seen that by reducing the length of the main channel and the number of electrodes at low frequencies and not changing the inlet flow velocities, cell separation was still achieved successfully, although with a slightly larger electrode voltage. The shorter main channel decreased the residence time for the cells on the chip and also reduced the overall size of the device-these were improvements over the original design. The obtained results can be used to analyze other cell types by knowing their size and dielectric properties to design geometries that can ensure separation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cooperative terrain model acquisition by a team of two or three point-robots

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

Rao, N.S.V.; Protopopescu, V.; Manickam, N.

1996-04-01

We address the model acquisition problem for an unknown planar terrain by a team of two or three robots. The terrain is cluttered by a finite number of polygonal obstacles whose shapes and positions are unknown. The robots are point-sized and equipped with visual sensors which acquire all visible parts of the terrain by scan operations executed from their locations. The robots communicate with each other via wireless connection. The performance is measured by the number of the sensor (scan) operations which are assumed to be the most time-consuming of all the robot operations. We employ the restricted visibility graphmore » methods in a hierarchical setup. For terrains with convex obstacles and for teams of n(= 2, 3) robots, we prove that the sensing time is reduced by a factor of 1/n. For terrains with concave corners, the performance of the algorithm depends on the number of concave regions and their depths. A hierarchical decomposition of the restricted visibility graph into n-connected and (n - 1)-or-less connected components is considered. The performance for the n(= 2, 3) robot team is expressed in terms of the sizes of n-connected components, and the sizes and diameters of (n - 1)-or-less connected components.« less

Physicochemical characterization of particulate emissions from a compression ignition engine employing two injection technologies and three fuels.

PubMed

Surawski, N C; Miljevic, B; Ayoko, G A; Roberts, B A; Elbagir, S; Fairfull-Smith, K E; Bottle, S E; Ristovski, Z D

2011-07-01

Alternative fuels and injection technologies are a necessary component of particulate emission reduction strategies for compression ignition engines. Consequently, this study undertakes a physicochemical characterization of diesel particulate matter (DPM) for engines equipped with alternative injection technologies (direct injection and common rail) and alternative fuels (ultra low sulfur diesel, a 20% biodiesel blend, and a synthetic diesel). Particle physical properties were addressed by measuring particle number size distributions, and particle chemical properties were addressed by measuring polycyclic aromatic hydrocarbons (PAHs) and reactive oxygen species (ROS). Particle volatility was determined by passing the polydisperse size distribution through a thermodenuder set to 300 °C. The results from this study, conducted over a four point test cycle, showed that both fuel type and injection technology have an impact on particle emissions, but injection technology was the more important factor. Significant particle number emission (54%-84%) reductions were achieved at half load operation (1% increase-43% decrease at full load) with the common rail injection system; however, the particles had a significantly higher PAH fraction (by a factor of 2 to 4) and ROS concentrations (by a factor of 6 to 16) both expressed on a test-cycle averaged basis. The results of this study have significant implications for the health effects of DPM emissions from both direct injection and common rail engines utilizing various alternative fuels.

Analysis of Demand for Decoders of Television Captioning for Deaf and Hearing-Impaired Children and Adults.

ERIC Educational Resources Information Center

Sherman, Renee Z.; Sherman, Joel D.

This market research report analyzed the published literature, the size of the deaf/severely hard-of-hearing population, factors that affect demand for closed-captioned television decoders, and the supply of decoders. The analysis found that the number of hearing-impaired people in the United States is between 16 and 21 million; hearing impairment…

Species performance: The relationship between nutrient availability, life history traits and stress [Chapter 8

Treesearch

Jeremy J. James

2012-01-01

Differences in species performance (i.e. how a species captures and utilizes resources to maintain and increase population size), influences the rate and direction of plant community change (Sheley et al., 2006). Species performance is determined by a number of interacting factors. This includes resource supply rates, physiological traits that determine how a species...

Sprout Singling in North Alabama Hardwoods

Treesearch

Kozma Naka; Philip G. Cannon

2004-01-01

Many commercial hardwood species grow quite well in northern Alabama and most regenerate by stump sprouts after harvest. The number of sprouts on a stump depends on several factors such as species and stump size. To determine if the practice of singling (removing all but the single best sprout from a stump) might be a means of accelerating the growth rate of one stem...

American Indian Organizational Education in Chicago: The Community Board Training Project, 1979-1989

ERIC Educational Resources Information Center

Laukaitis, John J.

2009-01-01

American Indian organizations in Chicago grew both in size and number during the 1970s. The lasting impact of War on Poverty programs and the passing of the Indian Education Act of 1972 and the Comprehensive Employment and Training Act of 1973 served as significant factors for the development of these organizations. Alternative American Indian…

Indicators of the Education Potential of the Population of Russia

ERIC Educational Resources Information Center

Tikhomirov, N. P.; Ushchev, V. I.

2007-01-01

The steady tendencies toward the decline in the size of Russia's population in the twenty-first century, owing to the effect of global political, social, and economic factors, are giving rise to a number of fundamental problems that have to do with the erosion of the conditions that are essential not only for the stable development of society, but…

Explaining outputs of primary health care: population and practice factors.

PubMed Central

Baker, D; Klein, R

1991-01-01

OBJECTIVE--To examine whether variations in the activities of general practice among family health service authorities can be explained by the populations characteristics and the organisation and resourcing of general practice. DESIGN--The family health services authorities were treated as discrete primary health care systems. Nineteen performance indicators reflecting the size, distribution, and characteristics of the population served; the organisation of general practice (inputs); and the activities generated by general practitioners and their staff (output) were analysed by stepwise regression. SETTING--90 family health services authorities in England. MAIN OUTCOME MEASURES--Rates of cervical smear testing, immunisation, prescribing, and night visiting. RESULTS--53% of the variation in uptake of cervical cytology was accounted for by Jarman score (t = -3.3), list inflation (-0.41), the proportion of practitioners over 65 (-0.64), the number of ancillary staff per practitioner (2.5), and 70% of the variation in immunisation rates by standardised mortality ratios (-6.6), the proportion of practitioners aged over 65 (-4.8), and the number of practice nurses per practitioner (3.5). Standardised mortality ratios (8.4), the number of practitioners (2.3), and the proportion over 65 (2.2), and the number of ancillary staff per practitioner (-3.1) accounted for 69% of variation in prescribing rates. 54% of the variation in night visiting was explained by standardised mortality ratios (7.1), the proportion of practitioners with lists sizes below 1000 (-2.2), the proportion aged over 65 (-0.4), and the number of practice nurses per practitioner (-2.5). CONCLUSIONS--Family health services authorities are appropriate systems for studying output of general practice. Their performance indicators need to be refined and to be linked to other relevant factors, notably the performance of hospital, community, and social services. PMID:1653065

Patient population with multiple myeloma and transitions across different lines of therapy in the USA: an epidemiologic model.

PubMed

Cid Ruzafa, Javier; Merinopoulou, Evie; Baggaley, Rebecca F; Leighton, Pamela; Werther, Winifred; Felici, Diana; Cox, Andrew

2016-08-01

Multiple myeloma (MM) is a progressive, malignant neoplasia with a worldwide, age-standardized annual incidence of 1.5 per 100 000 individuals and 5-year prevalence around 230 000 patients. Main favorable prognostic factors are younger age, low/standard cytogenetic risk, and undergoing stem cell transplantation. Our aim was to estimate the size of the patient population with MM eligible to receive a new MM therapy at different lines of therapy in the USA. We constructed a compartmental, differential equation model representing the flow of MM patients from diagnosis to death, via two possible treatment pathways and distinguished in four groups based on prognostic factors. Parameters were obtained from published references, available statistics, and assumptions. The model was used to estimate number of diagnosed MM patients and number of patient transitions from one line of therapy to the next over 1 year. Model output included 95% credible intervals from probabilistic sensitivity analyses. The base-case estimates were 80 219 patients living with MM, including 70 375 on treatment, 780 symptomatic untreated patients, and 9064 asymptomatic untreated patients. Over a 1-year period, the number of MM patients on treatment line 1 was estimated at 23 629 (credible intervals 22 236-25 029), and the number of transitions from treatment line 1 to treatment line 2 was estimated at 14 423. The size of the patient population with MM on different lines of therapy and in patient subgroups of interest estimated from this epidemiologic model can be used to assess the number of patients who could benefit from new MM therapies and their corresponding budgetary impact. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Effects of varying food and density on reproduction in Diaptomus clavipes Schacht

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

Cooney, J.D.; Gehrs, C.W.; Bunting, D.L. II

1978-05-01

Experiments were conducted to determine the effects of varying food and density on the egg production of the calanoid copepod, Diaptomus clavipes Schacht. These experiments were performed at both the population and organismic level. An attempt was also made to evaluate the feasibility of using a flow-through system to study the effects of various environmental factors on egg production in copepods. It was found that food supply was an important factor determining rate of clutch production, number of eggs per clutch, and size of individual eggs. As food supply decreased, both the rate of clutch production and the number ofmore » eggs per clutch decreased, but the size of individual eggs increased. During periods of extreme food shortage, not only did egg production cease, but also the production of spermatophores by males. When starved females were placed under optimum feeding conditions, they produced eggs within a few days and were producing maximally within two weeks. Egg production in the flow-through system was reduced, due primarily to food shortage. The trout chow solution which was used as food was inadequate because it was not directly utilized by the copepods.« less

Density effect on great tit (Parus major) clutch size intensifies in a polluted environment.

PubMed

Eeva, Tapio; Lehikoinen, Esa

2013-12-01

Long-term data on a great tit (Parus major) population breeding in a metal-polluted zone around a copper-nickel smelter indicate that, against expectations, the clutch size of this species is decreasing even though metal emissions in the area have decreased considerably over the past two decades. Here, we document long-term population-level changes in the clutch size of P. major and explore if changes in population density, population numbers of competing species, timing of breeding, breeding habitat, or female age distribution can explain decreasing clutch sizes. Clutch size of P. major decreased by one egg in the polluted zone during the past 21 years, while there was no significant change in clutch size in the unpolluted reference zone over this time period. Density of P. major nests was similar in both environments but increased threefold during the study period in both areas (from 0.8 to 2.4 nest/ha). In the polluted zone, clutch size has decreased as a response to a considerable increase in population density, while a corresponding density change in the unpolluted zone did not have such an effect. The other factors studied did not explain the clutch size trend. Fledgling numbers in the polluted environment have been relatively low since the beginning of the study period, and they do not show a corresponding decrease to that noted for the clutch size over the same time period. Our study shows that responses of commonly measured life-history parameters to anthropogenic pollution depend on the structure of the breeding population. Interactions between pollution and intrinsic population characters should therefore be taken into account in environmental studies.

Teamwork in high-risk environments analogous to space

NASA Technical Reports Server (NTRS)

Kanki, Barbara G.

1990-01-01

Mountaineering expeditions combine a number of factors which make them potentially good analogs to the planetary exploration facet of long-duration space missions. A study of mountain climbing teams was conducted in order to evaluate the usefulness of the environment as a space analog and to specifically identify the factors and issues surrounding teamwork and 'successful' team performance in two mountaineering environments. This paper focuses on social/organizational factors, including team size and structure, leadership styles and authority structure which were found in the sample of 22 climb teams (122 individuals). The second major issue discussed is the construction of a valid performance measure in this high-risk environment.

Application of Response Surface Methods To Determine Conditions for Optimal Genomic Prediction

PubMed Central

Howard, Réka; Carriquiry, Alicia L.; Beavis, William D.

2017-01-01

An epistatic genetic architecture can have a significant impact on prediction accuracies of genomic prediction (GP) methods. Machine learning methods predict traits comprised of epistatic genetic architectures more accurately than statistical methods based on additive mixed linear models. The differences between these types of GP methods suggest a diagnostic for revealing genetic architectures underlying traits of interest. In addition to genetic architecture, the performance of GP methods may be influenced by the sample size of the training population, the number of QTL, and the proportion of phenotypic variability due to genotypic variability (heritability). Possible values for these factors and the number of combinations of the factor levels that influence the performance of GP methods can be large. Thus, efficient methods for identifying combinations of factor levels that produce most accurate GPs is needed. Herein, we employ response surface methods (RSMs) to find the experimental conditions that produce the most accurate GPs. We illustrate RSM with an example of simulated doubled haploid populations and identify the combination of factors that maximize the difference between prediction accuracies of best linear unbiased prediction (BLUP) and support vector machine (SVM) GP methods. The greatest impact on the response is due to the genetic architecture of the population, heritability of the trait, and the sample size. When epistasis is responsible for all of the genotypic variance and heritability is equal to one and the sample size of the training population is large, the advantage of using the SVM method vs. the BLUP method is greatest. However, except for values close to the maximum, most of the response surface shows little difference between the methods. We also determined that the conditions resulting in the greatest prediction accuracy for BLUP occurred when genetic architecture consists solely of additive effects, and heritability is equal to one. PMID:28720710

Evolution of vehicle exhaust particles in the atmosphere.

PubMed

Canagaratna, Manjula R; Onasch, Timothy B; Wood, Ezra C; Herndon, Scott C; Jayne, John T; Cross, Eben S; Miake-Lye, Richard C; Kolb, Charles E; Worsnop, Douglas R

2010-10-01

Aerosol mass spectrometer (AMS) measurements are used to characterize the evolution of exhaust particulate matter (PM) properties near and downwind of vehicle sources. The AMS provides time-resolved chemically speciated mass loadings and mass-weighted size distributions of nonrefractory PM smaller than 1 microm (NRPM1). Source measurements of aircraft PM show that black carbon particles inhibit nucleation by serving as condensation sinks for the volatile and semi-volatile exhaust gases. Real-world source measurements of ground vehicle PM are obtained by deploying an AMS aboard a mobile laboratory. Characteristic features of the exhaust PM chemical composition and size distribution are discussed. PM mass and number concentrations are used with above-background gas-phase carbon dioxide (CO2) concentrations to calculate on-road emission factors for individual vehicles. Highly variable ratios between particle number and mass concentrations are observed for individual vehicles. NRPM1 mass emission factors measured for on-road diesel vehicles are approximately 50% lower than those from dynamometer studies. Factor analysis of AMS data (FA-AMS) is applied for the first time to map variations in exhaust PM mass downwind of a highway. In this study, above-background vehicle PM concentrations are highest close to the highway and decrease by a factor of 2 by 200 m away from the highway. Comparison with the gas-phase CO2 concentrations indicates that these vehicle PM mass gradients are largely driven by dilution. Secondary aerosol species do not show a similar gradient in absolute mass concentrations; thus, their relative contribution to total ambient PM mass concentrations increases as a function of distance from the highway. FA-AMS of single particle and ensemble data at an urban receptor site shows that condensation of these secondary aerosol species onto vehicle exhaust particles results in spatial and temporal evolution of the size and composition of vehicle exhaust PM on urban and regional scales.

A new criterion for predicting rolling-element fatigue lives of through-hardened steels

NASA Technical Reports Server (NTRS)

Chevalier, J. L.; Zaretsky, E. V.; Parker, R. J.

1972-01-01

A carbide factor was derived based upon a statistical analysis which related rolling-element fatigue life to the total number of residual carbide particles per unit area, median residual carbide size, and percent residual carbide area. An equation was experimentally determined which predicts material hardness as a function of temperature. The limiting temperatures of all of the materials studied were dependent on initial room temperature hardness and tempering temperature. An equation was derived combining the effects of material hardness, carbide factor, and bearing temperature to predict rolling-element bearing life.

33 CFR 173.27 - Numbers: Display; size; color.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Numbers: Display; size; color... (CONTINUED) BOATING SAFETY VESSEL NUMBERING AND CASUALTY AND ACCIDENT REPORTING Numbering § 173.27 Numbers: Display; size; color. (a) Each number required by § 173.15 must: (1) Be painted on or permanently attached...

33 CFR 173.27 - Numbers: Display; size; color.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Numbers: Display; size; color... (CONTINUED) BOATING SAFETY VESSEL NUMBERING AND CASUALTY AND ACCIDENT REPORTING Numbering § 173.27 Numbers: Display; size; color. (a) Each number required by § 173.15 must: (1) Be painted on or permanently attached...

The effects of the distribution pattern of multiple voids within LDPE on partial discharge characteristics

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

Shin, D.S.; Han, M.K.; Lee, J.H.

1996-12-31

In this paper, the authors have investigated effects of the arrangement of the voids in LDPE samples on PD characteristics, such as phase-related magnitude of PD, number of discharges. The differences of the PD patterns may be attributed to the arrangements of the voids. They have also employed available statistical operators, such as discharge factor and cross correlation factor in order to analyze the PD characteristics. The authors could conclude that partial discharge characteristics show quite different patterns due to the arrangements of voids in spite of the same size. The experimental results suggest that it is important to knowmore » the arrangements of the multiple voids as well as to obtain the information about the number of defects in the insulators.« less

Size- and time-dependent growth properties of human induced pluripotent stem cells in the culture of single aggregate.

PubMed

Nath, Suman C; Horie, Masanobu; Nagamori, Eiji; Kino-Oka, Masahiro

2017-10-01

Aggregate culture of human induced pluripotent stem cells (hiPSCs) is a promising method to obtain high number of cells for cell therapy applications. This study quantitatively evaluated the effects of initial cell number and culture time on the growth of hiPSCs in the culture of single aggregate. Small size aggregates ((1.1 ± 0.4) × 10 1 -(2.8 ± 0.5) × 10 1 cells/aggregate) showed a lower growth rate in comparison to medium size aggregates ((8.8 ± 0.8) × 10 1 -(6.8 ± 1.1) × 10 2 cells/aggregate) during early-stage of culture (24-72 h). However, when small size aggregates were cultured in conditioned medium, their growth rate increased significantly. On the other hand, large size aggregates ((1.1 ± 0.2) × 10 3 -(3.5 ± 1.1) × 10 3 cells/aggregate) showed a lower growth rate and lower expression level of proliferation marker (ki-67) in the center region of aggregate in comparison to medium size aggregate during early-stage of culture. Medium size aggregates showed the highest growth rate during early-stage of culture. Furthermore, hiPSCs proliferation was dependent on culture time because the growth rate decreased significantly during late-stage of culture (72-120 h) at which point collagen type I accumulated on the periphery of aggregate, suggesting blockage of diffusive transport of nutrients, oxygen and metabolites into and out of the aggregates. Consideration of initial cell number and culture time are important to maintain balance between autocrine factors secretion and extracellular matrix accumulation on the aggregate periphery to achieve optimal growth of hiPSCs in the culture of single aggregate. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Effect of stress during handling, seawater acclimation, confinement, and induced spawning on plasma ion levels and somatolactin-expressing cells in mature female Liza ramada.

PubMed

Khalil, Noha A; Hashem, Amal M; Ibrahim, Amal A E; Mousa, Mostafa A

2012-08-01

The present experiments were designed to determine the effect of different stress factors; handling, seawater acclimation, confinement, and induced spawning on plasma cortisol, hydro mineral balance as well as changes in size, number and integrated intensity of somatolactin (SL)-expressing cells in Liza ramada mature females confined to fresh water ponds. The plasma levels of cortisol, PO(4)(3-), Na(+), and K(+) were higher, while Ca(2+) and Mg(2+) were lower than controls during transportation without anesthesia. By using clove oil (5 mg L(-1)) as an anesthetic during transportation, the plasma cortisol, PO(4) (3-), Na(+), and K(+) were similar to controls, while Ca(2+) and Mg(2+) were higher. During seawater acclimation, the plasma cortisol and minerals were significantly higher except Na(+) which was lower than controls. In addition, during induction of spawning, the plasma levels of cortisol, PO(4)(3-), Na(+), K(+), and Mg(2+) were significantly higher than controls. The SL-producing cells are located in the pars intermedia (PI) bordering the neurohypophysis. The stress affected the number, size, and immunostaining of SL-expressing cells. During seawater acclimation, the size and the integrated intensity of SL immunoreactivity were lower, but the number of these cells was higher than controls. Furthermore, the number, size, and the integrated intensity of SL immunoreactivity were significantly lower than controls during handling and after spawning, which was opposite to confinement. The response of SL-expressing cells in PI in parallel with changes in cortisol and hydro mineral balance induced by stress support the possible role of SL in the adaptive response of fish to stress. © 2012 WILEY PERIODICALS, INC.

Predicting Likelihood of Having Four or More Positive Nodes in Patient With Sentinel Lymph Node-Positive Breast Cancer: A Nomogram Validation Study

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

Unal, Bulent; Gur, Akif Serhat; Beriwal, Sushil

2009-11-15

Purpose: Katz suggested a nomogram for predicting having four or more positive nodes in sentinel lymph node (SLN)-positive breast cancer patients. The findings from this formula might influence adjuvant radiotherapy decisions. Our goal was to validate the accuracy of the Katz nomogram. Methods and Materials: We reviewed the records of 309 patients with breast cancer who had undergone completion axillary lymph node dissection. The factors associated with the likelihood of having four or more positive axillary nodes were evaluated in patients with one to three positive SLNs. The nomogram developed by Katz was applied to our data set. The areamore » under the curve of the corresponding receiver operating characteristics curve was calculated for the nomogram. Results: Of the 309 patients, 80 (25.9%) had four or more positive axillary lymph nodes. On multivariate analysis, the number of positive SLNs (p < .0001), overall metastasis size (p = .019), primary tumor size (p = .0001), and extracapsular extension (p = .01) were significant factors predicting for four or more positive nodes. For patients with <5% probability, 90.3% had fewer than four positive nodes and 9.7% had four or more positive nodes. The negative predictive value was 91.7%, and sensitivity was 80%. The nomogram was accurate and discriminating (area under the curve, .801). Conclusion: The probability of four or more involved nodes is significantly greater in patients who have an increased number of positive SLNs, increased overall metastasis size, increased tumor size, and extracapsular extension. The Katz nomogram was validated in our patients. This nomogram will be helpful to clinicians making adjuvant treatment recommendations to their patients.« less

Standing wave design and optimization of a simulated moving bed chromatography for separation of xylobiose and xylose under the constraints on product concentration and pressure drop.

PubMed

Lee, Chung-Gi; Choi, Jae-Hwan; Park, Chanhun; Wang, Nien-Hwa Linda; Mun, Sungyong

2017-12-08

The feasibility of a simulated moving bed (SMB) technology for the continuous separation of high-purity xylobiose (X2) from the output of a β-xylosidase X1→X2 reaction has recently been confirmed. To ensure high economical efficiency of the X2 production method based on the use of xylose (X1) as a starting material, it is essential to accomplish the comprehensive optimization of the X2-separation SMB process in such a way that its X2 productivity can be maximized while maintaining the X2 product concentration from the SMB as high as possible in consideration of a subsequent lyophilization step. To address this issue, a suitable SMB optimization tool for the aforementioned task was prepared based on standing wave design theory. The prepared tool was then used to optimize the SMB operation parameters, column configuration, total column number, adsorbent particle size, and X2 yield while meeting the constraints on X2 purity, X2 product concentration, and pressure drop. The results showed that the use of a larger particle size caused the productivity to be limited by the constraint on X2 product concentration, and a maximum productivity was attained by choosing the particle size such that the effect of the X2-concentration limiting factor could be balanced with that of pressure-drop limiting factor. If the target level of X2 product concentration was elevated, higher productivity could be achieved by decreasing particle size, raising the level of X2 yield, and increasing the column number in the zones containing the front and rear of X2 solute band. Copyright © 2017 Elsevier B.V. All rights reserved.

Analysis of horse movements from non-commercial horse properties in New Zealand.

PubMed

Rosanowski, S M; Cogger, N; Rogers, C W; Bolwell, C F; Benschop, J; Stevenson, M A

2013-09-01

To investigate property-level factors associated with the movement of horses from non-commercial horse properties, including the size and location of the property, number and reason for keeping horses. Using a cross-sectional survey 2,912 questionnaires were posted to randomly selected non-commercial horse properties listed in a rural property database. The survey collected information about the number of horses, and reasons for keeping horses on the property, and any movement of horses in the previous 12 months. Three property-level outcomes were investigated; the movement status of the property, the frequency of movement events, and the median distance travelled from a property. Associations were examined using logistic regression and Kruskal-Wallis analysis of variance. In total 62.0% (488/791) of respondents reported at least one movement event in the year prior to the survey, for a total of 22,050 movement events. The number of movement events from a property varied significantly by the number of horses on the property (p<0.02), while the median distance travelled per property varied significantly by both region (p<0.03) and property size (p<0.01). Region, property size, the number of horses kept, and keeping horses for competition, recreation, racing or as pets were all significantly associated with movement status in the multivariable analyses (p<0.001). This study showed that there are characteristics of non-commercial horse properties that influence movement behaviour. During an exotic disease outbreak the ability to identify properties with these characteristics for targeted control will enhance the effectiveness of control measures.

Lifetime and per year productivity of sows in four pig farms in the tropics of Mexico.

PubMed

Ek-Mex, Jesús Enrique; Segura-Correa, José Candelario; Alzina-López, Alejandro; Batista-Garcia, Laura

2015-03-01

The objectives of this study were to estimate the lifetime and per year productivity of sows and to determine the effect of some factor on those traits in four pig farms in the tropics of Mexico. Data from 7526 sows for lifetime number of piglets born alive per sow (LBA), lifetime kilograms of piglets at farrowing (LKF), number of piglets born alive per year (NPF/Y), and kilograms of piglets at farrowing per year (KPF/Y); and data from 7230 sows for lifetime number of piglets weaned (LPW), lifetime kilograms of piglets weaned (LKW), number of piglets weaned per year (NPW/Y), and kilograms of piglets weaned per year (KPW/Y) per sow were used. The statistical model for all traits included the fixed effects of farm, year of first farrowing, season of first farrowing, litter size at first farrowing, age at first farrowing, removal reason, simple interactions, and the error term. The means for LBA, LKF, NPF/Y, and KPF/Y were 45.1 piglets, 67.1 kg, 22.7 piglets, and 33.7 kg, respectively. The means for LPW, LKW, NPW/Y, and KPW/Y were 43.2 piglets, 251.9 kg, 21.5 piglets, and 125.1 kg, respectively. All factors were significant for all traits, except for age at first farrowing on LPW and LKW. Sows with large litter sizes and those that farrowed the first time, at an early age, had the highest lifetime and per year productivity. Therefore, more care and better management should be provided to those types of sows to improve the farms profit.

Household demographic determinants of Ebola epidemic risk.

PubMed

Adams, Ben

2016-03-07

A salient characteristic of Ebola, and some other infectious diseases such as Tuberculosis, is intense transmission among small groups of cohabitants and relatively limited indiscriminate transmission in the wider population. Here we consider a mathematical model for an Ebola epidemic in a population structured into households of equal size. We show that household size, a fundamental demographic unit, is a critical factor that determines the vulnerability of a community to epidemics, and the effort required to control them. Our analysis is based on the household reproduction number, but we also consider the basic reproduction number, intrinsic growth rate and final epidemic size. We show that, when other epidemiological parameters are kept the same, all of these quantifications of epidemic growth and size are increased by larger households and more intense within-household transmission. We go on to model epidemic control by case detection and isolation followed by household quarantine. We show that, if household quarantine is ineffective, the critical probability with which cases must be detected to halt an epidemic increases significantly with each increment in household size and may be a very challenging target for communities composed of large households. Effective quarantine may, however, mitigate the detrimental impact of large household sizes. We conclude that communities composed of large households are fundamentally more vulnerable to epidemics of infectious diseases primarily transmitted by close contact, and any assessment of control strategies for these epidemics should take into account the demographic structure of the population. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Laboratory Assessment of Factors That Affect Bacterial Adhesion to Contact Lenses

PubMed Central

Dutta, Debarun; Willcox, Mark DP

2013-01-01

Adhesion of pathogenic microbes, particularly bacteria, to contact lenses is implicated in contact lens related microbial adverse events. Various in vitro conditions such as type of bacteria, the size of initial inoculum, contact lens material, nutritional content of media, and incubation period can influence bacterial adhesion to contact lenses and the current study investigated the effect of these conditions on bacterial adhesion to contact lenses. There was no significant difference in numbers of bacteria that adhered to hydrogel etafilcon A or silicone hydrogel senofilcon A contact lenses. Pseudomonas aeruginosa adhered in higher numbers compared to Staphylococcus aureus. Within a genera/species, adhesion of different bacterial strains did not differ appreciably. The size of initial inoculum, nutritional content of media, and incubation period played significant roles in bacterial adhesion to lenses. A set of in vitro assay conditions to help standardize adhesion between studies have been recommended. PMID:24833224

Detecting a Weak Association by Testing its Multiple Perturbations: a Data Mining Approach

NASA Astrophysics Data System (ADS)

Lo, Min-Tzu; Lee, Wen-Chung

2014-05-01

Many risk factors/interventions in epidemiologic/biomedical studies are of minuscule effects. To detect such weak associations, one needs a study with a very large sample size (the number of subjects, n). The n of a study can be increased but unfortunately only to an extent. Here, we propose a novel method which hinges on increasing sample size in a different direction-the total number of variables (p). We construct a p-based `multiple perturbation test', and conduct power calculations and computer simulations to show that it can achieve a very high power to detect weak associations when p can be made very large. As a demonstration, we apply the method to analyze a genome-wide association study on age-related macular degeneration and identify two novel genetic variants that are significantly associated with the disease. The p-based method may set a stage for a new paradigm of statistical tests.

Butterfly Larval Host Plant use in a Tropical Urban Context: Life History Associations, Herbivory, and Landscape Factors

PubMed Central

Tiple, Ashish D.; Khurad, Arun M.; Dennis, Roger L. H.

2011-01-01

This study examines butterfly larval host plants, herbivory and related life history attributes within Nagpur City, India. The larval host plants of 120 butterfly species are identified and their host specificity, life form, biotope, abundance and perennation recorded; of the 126 larval host plants, most are trees (49), with fewer herbs (43), shrubs (22), climbers (7) and stem parasites (2). They include 89 wild, 23 cultivated, 11 wild/cultivated and 3 exotic plant species; 78 are perennials, 43 annuals and 5 biannuals. Plants belonging to Poaceae and Fabaceae are most widely used by butterfly larvae. In addition to distinctions in host plant family affiliation, a number of significant differences between butterfly families have been identified in host use patterns: for life forms, biotopes, landforms, perennation, host specificity, egg batch size and ant associations. These differences arising from the development of a butterfly resource database have important implications for conserving butterfly species within the city area. Differences in overall butterfly population sizes within the city relate mainly to the number of host plants used, but other influences, including egg batch size and host specificity are identified. Much of the variation in population size is unaccounted for and points to the need to investigate larval host plant life history and strategies as population size is not simply dependent on host plant abundance. PMID:21864159

Experimental evaluation of the optical quality of DMD SLM for its application as Fourier holograms displaying device

NASA Astrophysics Data System (ADS)

Molodtsov, D. Y.; Cheremkhin, P. A.; Krasnov, V. V.; Rodin, V. G.

2016-04-01

In this paper, the optical quality of micromirror DMD spatial light modulator (SLM) is evaluated and its applicability as an output device for holographic filters in dispersive correlators is analyzed. The possibility of using of DMD SLM extracted from consumer DLP-projector was experimentally evaluated by displaying of Fourier holograms. Software for displaying of holograms was developed. Experiments on holograms reconstruction was conducted with a different number of holograms pixels (and different placement on SLM). Reduction of number of pixels of output hologram (i.e. size of minimum resolvable element) led to improvement of reconstructed image quality. The evaluation shows that not every DMD-chip has acceptable optical quality for its application as display device for Fourier holograms. It was determined that major factor of reconstructed image quality degradation is a curvature of surface of SLM or its safety glass. Ranging hologram size allowed to estimate approximate size of sufficiently flat area of SLM matrix. For tested SLM it was about 1.5 mm. Further hologram size increase led to significant reconstructed image quality degradation. Developed and applied a technique allows to quickly estimate maximum size of holograms that can be displayed with specific SLM without significant degradation of reconstructed image. Additionally it allows to identify areas on the SLM with increased curvature of the surface.

Factors associated with daily walking of dogs.

PubMed

Westgarth, Carri; Christian, Hayley E; Christley, Robert M

2015-05-19

Regular physical activity is beneficial to the health of both people and animals. The role of regular exercise undertaken together, such as dog walking, is a public health interest of mutual benefit. Exploration of barriers and incentives to regular dog walking by owners is now required so that effective interventions to promote it can be designed. This study explored a well-characterised cross-sectional dataset of 276 dogs and owners from Cheshire, UK, for evidence of factors associated with the dog being walked once or more per day. Factors independently associated with daily walking included: number of dogs owned (multiple (vs. single) dogs negatively associated); size (medium and possibly large dogs (vs. small) positively associated); and number of people in the household (more people negatively associated). Furthermore, a number of factors related to the dog-owner relationship and the dog's behaviour were associated with daily walking, including: having acquired the dog for a hobby (positively associated); dog lying on furniture (positively associated); dog lying on laps (negatively associated); growling at household members (negatively associated); and playing chase games with the dog (negatively associated). These findings are consistent with the hypothesis that the strength and nature of the human-dog relationship incentivises dog walking, and that behavioural and demographic factors may affect dog walking via this mechanism. Future studies need to investigate how dog demographic and behavioural factors, plus owner behavioural factors and perceptions of the dog, influence the dog-human relationship in respect to the perceived support and motivation a dog can provide for walking.

Electric wind in a Differential Mobility Analyzer

DOE PAGES

Palo, Marus; Meelis Eller; Uin, Janek; ...

2015-10-25

Electric wind -- the movement of gas, induced by ions moving in an electric field -- can be a distorting factor in size distribution measurements using Differential Mobility Analyzers (DMAs). The aim of this study was to determine the conditions under which electric wind occurs in the locally-built VLDMA (Very Long Differential Mobility Analyzer) and TSI Long-DMA (3081) and to describe the associated distortion of the measured spectra. Electric wind proved to be promoted by the increase of electric field strength, aerosol layer thickness, particle number concentration and particle size. The measured size spectra revealed three types of distortion: wideningmore » of the size distribution, shift of the mode of the distribution to smaller diameters and smoothing out the peaks of the multiply charged particles. Electric wind may therefore be a source of severe distortion of the spectrum when measuring large particles at high concentrations.« less

Mass and heat transfer in crushed oil shale

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

Carley, J.F.; Straub, J.S.; Ott, L.L.

1984-04-01

Heat and mass transfer between gases and oil-shale particles are both important for all proposed retorting processes. Past studies of transfer in packed beds, which have disagreed substantially in their results, have nearly all been done with beds of regular particles of uniform size, whereas oil-shale retorting involves particles of diverse shapes and widely ranging sizes. To resolve these questions, we have made 349 runs in which we measured mass-transfer rates from naphthalene particles of diverse shapes buried in packed beds through which air was passed at room temperature. This technique permits calculation of the mass-transfer coefficient for each activemore » particle in the bed rather than, as in most past studies, for the bed as a whole. The data were analyzed in two ways: (1) by the traditional correlation of Colburn j/sub D/ vs Reynolds number and (2) by multiple regression of the mass-transfer coefficient on air rate, traditional correlation of Colburn j/sub D/ vs Reynolds number and (3) by multiple regression of the mass-transfer coefficient on air rate, sizes of active and inert particles, void fraction, and temperature. Principal findings are: (1) local Reynolds number should be based on active particle size rather than average size for the bed; (2) no appreciable differences were seen between shallow beds and deep ones; (3) mass transfer was 26% faster for spheres and lozenges buried in shale than for all-sphere beds; (4) orientation of lozenges in shale beds has little effect on mass-transfer rate; (5) a useful summarizing equation for either mass or heat transfer in shale beds is log j.epsilon = -.0747 - .6344 log Re + .0592 log/sup 2/Re where j = either j/sub D/ or j/sub H/, the Chilton-Colburn j-factors for mass and heat transfer, Re = the Reynolds number defined for packed beds, and epsilon = the void fraction in the bed. 12 references, 15 figures.« less

On the competition among aerosol number, size and composition in predicting CCN variability: a multi-annual field study in an urbanized desert.

PubMed

Crosbie, E; Youn, J-S; Balch, B; Wonaschütz, A; Shingler, T; Wang, Z; Conant, W C; Betterton, E A; Sorooshian, A

2015-02-10

A 2-year data set of measured CCN (cloud condensation nuclei) concentrations at 0.2 % supersaturation is combined with aerosol size distribution and aerosol composition data to probe the effects of aerosol number concentrations, size distribution and composition on CCN patterns. Data were collected over a period of 2 years (2012-2014) in central Tucson, Arizona: a significant urban area surrounded by a sparsely populated desert. Average CCN concentrations are typically lowest in spring (233 cm -3 ), highest in winter (430 cm -3 ) and have a secondary peak during the North American monsoon season (July to September; 372 cm -3 ). There is significant variability outside of seasonal patterns, with extreme concentrations (1 and 99 % levels) ranging from 56 to 1945 cm -3 as measured during the winter, the season with highest variability. Modeled CCN concentrations based on fixed chemical composition achieve better closure in winter, with size and number alone able to predict 82% of the variance in CCN concentration. Changes in aerosol chemical composition are typically aligned with changes in size and aerosol number, such that hygroscopicity can be parameterized even though it is still variable. In summer, models based on fixed chemical composition explain at best only 41% (pre-monsoon) and 36% (monsoon) of the variance. This is attributed to the effects of secondary organic aerosol (SOA) production, the competition between new particle formation and condensational growth, the complex interaction of meteorology, regional and local emissions and multi-phase chemistry during the North American monsoon. Chemical composition is found to be an important factor for improving predictability in spring and on longer timescales in winter. Parameterized models typically exhibit improved predictive skill when there are strong relationships between CCN concentrations and the prevailing meteorology and dominant aerosol physicochemical processes, suggesting that similar findings could be possible in other locations with comparable climates and geography.

Mammalian Collection on Noah's Ark: The Effects of Beauty, Brain and Body Size

PubMed Central

Frynta, Daniel; Šimková, Olga; Lišková, Silvie; Landová, Eva

2013-01-01

The importance of today's zoological gardens as the so-called “Noah's Ark” grows as the natural habitat of many species quickly diminishes. Their potential to shelter a large amount of individuals from many species gives us the opportunity to reintroduce a species that disappeared in nature. However, the selection of animals to be kept in zoos worldwide is highly selective and depends on human decisions driven by both ecological criteria such as population size or vulnerability and audience-driven criteria such as aesthetic preferences. Thus we focused our study on the most commonly kept and bred animal class, the mammals, and we asked which factors affect various aspects of the mammalian collection of zoos. We analyzed the presence/absence, population size, and frequency per species of each of the 123 mammalian families kept in the worldwide zoo collection. Our aim was to explain these data using the human-perceived attractiveness of mammalian families, their body weight, relative brain size and species richness of the family. In agreement with various previous studies, we found that the body size and the attractiveness of mammals significantly affect all studied components of the mammalian collection of zoos. There is a higher probability of the large and attractive families to be kept. Once kept, these animals are presented in larger numbers in more zoos. On the contrary, the relative mean brain size only affects the primary selection whether to keep the family or not. It does not affect the zoo population size or the number of zoos that keep the family. PMID:23690985

Mammalian collection on Noah's Ark: the effects of beauty, brain and body size.

PubMed

Frynta, Daniel; Šimková, Olga; Lišková, Silvie; Landová, Eva

2013-01-01

The importance of today's zoological gardens as the so-called "Noah's Ark" grows as the natural habitat of many species quickly diminishes. Their potential to shelter a large amount of individuals from many species gives us the opportunity to reintroduce a species that disappeared in nature. However, the selection of animals to be kept in zoos worldwide is highly selective and depends on human decisions driven by both ecological criteria such as population size or vulnerability and audience-driven criteria such as aesthetic preferences. Thus we focused our study on the most commonly kept and bred animal class, the mammals, and we asked which factors affect various aspects of the mammalian collection of zoos. We analyzed the presence/absence, population size, and frequency per species of each of the 123 mammalian families kept in the worldwide zoo collection. Our aim was to explain these data using the human-perceived attractiveness of mammalian families, their body weight, relative brain size and species richness of the family. In agreement with various previous studies, we found that the body size and the attractiveness of mammals significantly affect all studied components of the mammalian collection of zoos. There is a higher probability of the large and attractive families to be kept. Once kept, these animals are presented in larger numbers in more zoos. On the contrary, the relative mean brain size only affects the primary selection whether to keep the family or not. It does not affect the zoo population size or the number of zoos that keep the family.

A Genetic Algorithm for Flow Shop Scheduling with Assembly Operations to Minimize Makespan

NASA Astrophysics Data System (ADS)

Bhongade, A. S.; Khodke, P. M.

2014-04-01

Manufacturing systems, in which, several parts are processed through machining workstations and later assembled to form final products, is common. Though scheduling of such problems are solved using heuristics, available solution approaches can provide solution for only moderate sized problems due to large computation time required. In this work, scheduling approach is developed for such flow-shop manufacturing system having machining workstations followed by assembly workstations. The initial schedule is generated using Disjunctive method and genetic algorithm (GA) is applied further for generating schedule for large sized problems. GA is found to give near optimal solution based on the deviation of makespan from lower bound. The lower bound of makespan of such problem is estimated and percent deviation of makespan from lower bounds is used as a performance measure to evaluate the schedules. Computational experiments are conducted on problems developed using fractional factorial orthogonal array, varying the number of parts per product, number of products, and number of workstations (ranging upto 1,520 number of operations). A statistical analysis indicated the significance of all the three factors considered. It is concluded that GA method can obtain optimal makespan.

All atypia diagnosed at stereotactic vacuum-assisted breast biopsy do not need surgical excision.

PubMed

de Mascarel, Isabelle; Brouste, Véronique; Asad-Syed, Maryam; Hurtevent, Gabrielle; Macgrogan, Gaëtan

2011-09-01

The necessity of excision is debatable when atypia are diagnosed at stereotactic vacuum-assisted breast biopsy (microbiopsy). Among the 287 surgical excisions performed at Institut Bergonié from 1999 to 2009, we selected a case-control study group of 151 excisions; 52 involving all the diagnosed cancers and 99 randomly selected among the 235 excisions without cancer, following atypical microbiopsy (24 flat epithelial atypia; 50 atypical ductal hyperplasia; 14 lobular neoplasia; 63 mixed lesions). Mammographical calcification (type, extension, complete removal) and histological criteria of epithelial atypia (type, number of foci, size/extension), topography and microcalcification extension at microbiopsy were compared according to the presence or absence of cancer at excision. Factors associated with cancer at excision were Breast Imaging Reporting and Data System (BI-RADS5) lesions, large and/or multiple foci of mammographical calcifications, histological type, number, size and extension of atypical foci. Flat epithelial atypia alone was never associated with cancer at excision. BI-RADS5, atypical ductal hyperplasia (alone or predominant) and >3 foci of atypia were identified as independent pejorative factors. There was never any cancer at excision when these pejorative factors were absent (n=31). Presence of one (n=59), two (n=23) or three (n=14) factors was associated with cancer in 24, 15 and 13 cases with an odds ratio=5.8 (95% CI: 3-11.2) for each additional factor. We recommend that mammographical data and histological characteristics be taken into account in the decision-making process after diagnosis of atypia on microbiopsy. With experienced senologists and strict histological criteria, some patients could be spared surgery resulting in significant patient, financial and time advantages.

An observational study of the hygroscopic properties of aerosols over the Pearl River Delta region

NASA Astrophysics Data System (ADS)

Tan, Haobo; Yin, Yan; Gu, Xuesong; Li, Fei; Chan, P. W.; Xu, Hanbing; Deng, Xuejiao; Wan, Qilin

2013-10-01

Hygroscopic growth can significantly affect size distribution and activation of aerosol particles, as well as their effects on human health, atmospheric visibility, and climate. In this study, an H-TDMA (Hygroscopic Tandem Differential Mobility Analyzer) was utilized to measure hygroscopic growth factor and mixing state of aerosol particles at the CAWNET station in Panyu, Guangzhou, China. A statistical analysis of the results show that, at relative humidity (RH) of 90%, for less-hygroscopic particles of 40-200 nm in diameter, the growth factor (gLH) was around 1.13, while the number fraction (NFLH) varied between 0.41 ± 0.136 and 0.26 ± 0.078; for more-hygroscopic particles, the growth factor (gMH) varied between 1.46 and 1.55 with the average equivalent ammonium sulfate ratio (ɛAS) ranging from 0.63 to 0.68. The differences in ɛAS among particle of different sizes reveal that more-hygroscopic inorganic salts, such as ammonium sulfate and ammonium nitrate, are of more effective condensation growth for Aitken mode particles. A combined analysis of the probability density function of growth factor (Gf-PDF) and simultaneous meteorological data shows that during clean periods with air masses moving from the north, the particles are more likely to have homogeneous chemical composition, while during polluted or pollution accumulation periods, variations in mean number weighted growth factor (gmean) and NFMH become more pronounced, indicating that locally-emitted aerosol particles tend to be in an externally mixed state and contain a certain proportion of less-hygroscopic particles. This study can help improve our understanding of aerosol hygroscopicity and its impact on the atmospheric visibility and environment.

Applying n-bit floating point numbers and integers, and the n-bit filter of HDF5 to reduce file sizes of remote sensing products in memory-sensitive environments

NASA Astrophysics Data System (ADS)

Zinke, Stephan

2017-02-01

Memory sensitive applications for remote sensing data require memory-optimized data types in remote sensing products. Hierarchical Data Format version 5 (HDF5) offers user defined floating point numbers and integers and the n-bit filter to create data types optimized for memory consumption. The European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) applies a compaction scheme to the disseminated products of the Day and Night Band (DNB) data of Suomi National Polar-orbiting Partnership (S-NPP) satellite's instrument Visible Infrared Imager Radiometer Suite (VIIRS) through the EUMETSAT Advanced Retransmission Service, converting the original 32 bits floating point numbers to user defined floating point numbers in combination with the n-bit filter for the radiance dataset of the product. The radiance dataset requires a floating point representation due to the high dynamic range of the DNB. A compression factor of 1.96 is reached by using an automatically determined exponent size and an 8 bits trailing significand and thus reducing the bandwidth requirements for dissemination. It is shown how the parameters needed for user defined floating point numbers are derived or determined automatically based on the data present in a product.

The ART of mating: alternative reproductive tactics and mating success in a nest-guarding fish.

PubMed

Mascolino, S; Benvenuto, C; Gubili, C; Sacchi, C; Boufana, B; Mariani, S

2016-12-01

Behavioural observations in the field of male Mediterranean damselfish Chromis chromis were combined with molecular analyses, using bi-parentally and maternally inherited markers, to investigate reproductive success patterns of alternative reproductive tactics (ARTs) in terms of number of eggs sired and number of females contributing to each nest. Cuckoldry was observed in every nest sampled, with at least two and up to seven sneaker males per nest. The nesting male, however, always significantly fertilized the greater number of eggs (on average 49%) in each clutch, whereas each sneaker fertilized around 7% of the clutch. The average number of females whose eggs were fertilized by nesting males was 6·76 (range 2-13), while each sneaker on average fertilized the eggs of 1·74 (range 1-8) females. Using this sibship reconstruction, some of the factors involved in the regulation of the dynamic equilibrium of reproductive success were investigated between the two ARTs shown by C. chromis males. Results show that the sneakers' reproductive success was positively linked to egg clutch size; the density of individuals in the nesting area negatively affected the size of egg clutches; the rate of defence behaviours performed by nesting males negatively influenced the number of females contributing to each nest. © 2016 The Fisheries Society of the British Isles.

A high-throughput method for generating uniform microislands for autaptic neuronal cultures

PubMed Central

Sgro, Allyson E.; Nowak, Amy L.; Austin, Naola S.; Custer, Kenneth L.; Allen, Peter B.; Chiu, Daniel T.; Bajjalieh, Sandra M.

2013-01-01

Generating microislands of culture substrate on coverslips by spray application of poly-D lysine is a commonly used method for culturing isolated neurons that form self (autaptic) synapses. This preparation has multiple advantages for studying synaptic transmission in isolation; however, generating microislands by spraying produces islands of non-uniform size and thus cultures vary widely in the number of islands containing single neurons. To address these problems, we developed a high-throughput method for reliably generating uniformly-shaped microislands of culture substrate. Stamp molds formed of poly(dimethylsiloxane) (PDMS) were fabricated with arrays of circles and used to generate stamps made of 9.2% agarose. The agarose stamps were capable of loading sufficient poly D-lysine and collagen dissolved in acetic acid to rapidly generate coverslips containing at least 64 microislands per coverslip. When hippocampal neurons were cultured on these coverslips, there were significantly more single-neuron islands per coverslip. We noted that single neurons tended to form one of three distinct neurite-arbor morphologies, which varied with island size and the location of the cell body on the island. To our surprise, the number of synapses per autaptic neuron did not correlate with arbor shape or island size, suggesting that other factors regulate the number of synapses formed by isolated neurons. The stamping method we report can be used to increase the number of single-neuron islands per culture and aid in the rapid visualization of microislands. PMID:21515305

[Prognostic factors for severe infection after flexible ureteroscopy: Clinical interest of urine culture the day before surgery?].

PubMed

Alezra, E; Lasselin, J; Forzini, T; François, T; Viart, L; Saint, F

2016-01-01

The objectives of this study have been to determine prognostic factors for acute pyelonephritis (AP) after flexible ureteroscopy (FU), to assess the frequency of readmission for AP and to study the usefulness of urinalysis the day before surgery. Between 2010 and 2013, 266 patients have had at least one ureteroscopy (n=325). All infectious complications and unplanned readmissions within the month after FU were retrospectively evaluated. Several data have been collected: age, sex, BMI, surgical indication (calculis or tumor), number of previous ureteroscopies, number of previous surgeries for calculis, stones number, size and location, bilateral interventions, operating time, preoperative ureteral stenting, postoperative stenting, hospitalization stay, urine culture the day before surgery (j-1) and prescription of antibiotic therapy the week before FU. Correlation between these variables and acute pyelonephritis (AP) the month following the USSR was tested (StatView 4.5, SAS Institute) (P<0.05 significant). We observed 24 postoperative APs (7.4%), 17 prior to hospital discharge and 7 requiring rehospitalization. In univariate analysis, the significant prognostic factors of postoperative AP have been: stone size (>14 mm) (P=0.03); operating time (70 minutes) (P<0.005); positive day - 1 urine culture (P<0.001); antibiotics treatment the week before FU (P<0.001). In multivariate analysis, antibiotics prescription during the week before USSR remained significant (P<0.002; RR 5.8 [1.9-15]). Acute pyelonephritis requiring unplanned admission after ureteroscopy is a rare complication (2.4%). Urinalysis one day before ureteroscopy could allow early antibiotic therapy and may reduce 63% of unplanned hospital admissions for acute pyelonephritis. 5. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Time-dependent solutions for a stochastic model of gene expression with molecule production in the form of a compound Poisson process.

PubMed

Jędrak, Jakub; Ochab-Marcinek, Anna

2016-09-01

We study a stochastic model of gene expression, in which protein production has a form of random bursts whose size distribution is arbitrary, whereas protein decay is a first-order reaction. We find exact analytical expressions for the time evolution of the cumulant-generating function for the most general case when both the burst size probability distribution and the model parameters depend on time in an arbitrary (e.g., oscillatory) manner, and for arbitrary initial conditions. We show that in the case of periodic external activation and constant protein degradation rate, the response of the gene is analogous to the resistor-capacitor low-pass filter, where slow oscillations of the external driving have a greater effect on gene expression than the fast ones. We also demonstrate that the nth cumulant of the protein number distribution depends on the nth moment of the burst size distribution. We use these results to show that different measures of noise (coefficient of variation, Fano factor, fractional change of variance) may vary in time in a different manner. Therefore, any biological hypothesis of evolutionary optimization based on the nonmonotonic dependence of a chosen measure of noise on time must justify why it assumes that biological evolution quantifies noise in that particular way. Finally, we show that not only for exponentially distributed burst sizes but also for a wider class of burst size distributions (e.g., Dirac delta and gamma) the control of gene expression level by burst frequency modulation gives rise to proportional scaling of variance of the protein number distribution to its mean, whereas the control by amplitude modulation implies proportionality of protein number variance to the mean squared.

Workplace exposure to nanoparticles from gas metal arc welding process

NASA Astrophysics Data System (ADS)

Zhang, Meibian; Jian, Le; Bin, Pingfan; Xing, Mingluan; Lou, Jianlin; Cong, Liming; Zou, Hua

2013-11-01

Workplace exposure to nanoparticles from gas metal arc welding (GMAW) process in an automobile manufacturing factory was investigated using a combination of multiple metrics and a comparison with background particles. The number concentration (NC), lung-deposited surface area concentration (SAC), estimated SAC and mass concentration (MC) of nanoparticles produced from the GMAW process were significantly higher than those of background particles before welding ( P < 0.01). A bimodal size distribution by mass for welding particles with two peak values (i.e., 10,000-18,000 and 560-320 nm) and a unimodal size distribution by number with 190.7-nm mode size or 154.9-nm geometric size were observed. Nanoparticles by number comprised 60.7 % of particles, whereas nanoparticles by mass only accounted for 18.2 % of the total particles. The morphology of welding particles was dominated by the formation of chain-like agglomerates of primary particles. The metal composition of these welding particles consisted primarily of Fe, Mn, and Zn. The size distribution, morphology, and elemental compositions of welding particles were significantly different from background particles. Working activities, sampling distances from the source, air velocity, engineering control measures, and background particles in working places had significant influences on concentrations of airborne nanoparticle. In addition, SAC showed a high correlation with NC and a relatively low correlation with MC. These findings indicate that the GMAW process is able to generate significant levels of nanoparticles. It is recommended that a combination of multiple metrics is measured as part of a well-designed sampling strategy for airborne nanoparticles. Key exposure factors, such as particle agglomeration/aggregation, background particles, working activities, temporal and spatial distributions of the particles, air velocity, engineering control measures, should be investigated when measuring workplace exposure to nanoparticles.

Unit Reynolds number, Mach number and pressure gradient effects on laminar-turbulent transition in two-dimensional boundary layers

NASA Astrophysics Data System (ADS)

Risius, Steffen; Costantini, Marco; Koch, Stefan; Hein, Stefan; Klein, Christian

2018-05-01

The influence of unit Reynolds number (Re_1=17.5× 106-80× 106 {m}^{-1}), Mach number (M= 0.35-0.77) and incompressible shape factor (H_{12} = 2.50-2.66) on laminar-turbulent boundary layer transition was systematically investigated in the Cryogenic Ludwieg-Tube Göttingen (DNW-KRG). For this investigation the existing two-dimensional wind tunnel model, PaLASTra, which offers a quasi-uniform streamwise pressure gradient, was modified to reduce the size of the flow separation region at its trailing edge. The streamwise temperature distribution and the location of laminar-turbulent transition were measured by means of temperature-sensitive paint (TSP) with a higher accuracy than attained in earlier measurements. It was found that for the modified PaLASTra model the transition Reynolds number (Re_{ {tr}}) exhibits a linear dependence on the pressure gradient, characterized by H_{12}. Due to this linear relation it was possible to quantify the so-called `unit Reynolds number effect', which is an increase of Re_{ {tr}} with Re_1. By a systematic variation of M, Re_1 and H_{12} in combination with a spectral analysis of freestream disturbances, a stabilizing effect of compressibility on boundary layer transition, as predicted by linear stability theory, was detected (`Mach number effect'). Furthermore, two expressions were derived which can be used to calculate the transition Reynolds number as a function of the amplitude of total pressure fluctuations, Re_1 and H_{12}. To determine critical N-factors, the measured transition locations were correlated with amplification rates, calculated by incompressible and compressible linear stability theory. By taking into account the spectral level of total pressure fluctuations at the frequency of the most amplified Tollmien-Schlichting wave at transition location, the scatter in the determined critical N-factors was reduced. Furthermore, the receptivity coefficients dependence on incidence angle of acoustic waves was used to correct the determined critical N-factors. Thereby, a found dependency of the determined critical N-factors on H_{12} decreased, leading to an average critical N-factor of about 9.5 with a standard deviation of σ ≈ 0.8.

In vitro propagation of male germline stem cells from piglets.

PubMed

Zheng, Yi; Tian, Xiue; Zhang, Yaqing; Qin, Jinzhou; An, Junhui; Zeng, Wenxian

2013-07-01

To study the effects of serum and growth factors on propagation of porcine male germline stem cells (MGSCs) in vitro and develop a culture system for these stem cells. Fresh testicular cells from neonatal piglets were obtained by mechanical dissociation and collagenase-trypsin digestion. After differential plating, non-adhering cells were cultured in media supplemented with different concentrations of serum (0, 1 %, 2 %, 5 %, 10 %). After 10 days of primary culture, the cells were maintained in media supplemented with different concentrations of growth factors (basic fibroblast growth factor and epidermal growth factor at 1, 5, 10 ng/ml). The number of MGSC-derived colonies with different sizes was determined in each treatment to assess the effects of serum concentrations and growth factors. The number of MGSC-derived colonies was significantly higher in the presence of 1 % rather than 10 % fetal bovine serum (FBS). Basic fibroblast growth factor (bFGF) at 1, 5 ng/ml and epidermal growth factor (EGF) at 5, 10 ng/ml significantly promoted colony formation. Immunocytochemistry, reverse transcriptase-polymerase chain reaction (RT-PCR) and xenotransplantation assays demonstrated the presence of functional stem cells in cultured cell population. In vitro propagation of porcine MGSCs could be maintained in the presence of 1 % FBS and supplementation of growth factors for 1 month.

Stress and inflammation reduce brain-derived neurotrophic factor expression in first-episode psychosis: a pathway to smaller hippocampal volume.

PubMed

Mondelli, Valeria; Cattaneo, Annamaria; Murri, Martino Belvederi; Di Forti, Marta; Handley, Rowena; Hepgul, Nilay; Miorelli, Ana; Navari, Serena; Papadopoulos, Andrew S; Aitchison, Katherine J; Morgan, Craig; Murray, Robin M; Dazzan, Paola; Pariante, Carmine M

2011-12-01

Reduced brain-derived neurotrophic factor (BDNF) levels have been reported in the serum and plasma of patients with psychosis. The aim of this cross-sectional case-control study was to investigate potential causes and consequences of reduced BDNF expression in these patients by examining the association between BDNF levels and measures of stress, inflammation, and hippocampal volume in first-episode psychosis. Brain-derived neurotrophic factor, interleukin (IL)-6, and tumor necrosis factor (TNF)-α messenger RNA levels were measured in the leukocytes of 49 first-episode psychosis patients (DSM-IV criteria) and 30 healthy controls, all aged 18 to 65 years, recruited between January 2006 and December 2008. Patients were recruited from inpatient and outpatient units of the South London and Maudsley National Health Service Foundation Trust in London, United Kingdom, and the healthy controls were recruited from the same catchment area via advertisement and volunteer databases. In these same subjects, we measured salivary cortisol levels and collected information about psychosocial stressors (number of childhood traumas, number of recent stressors, and perceived stress). Finally, hippocampal volume was measured using brain magnetic resonance imaging in a subsample of 19 patients. Patients had reduced BDNF (effect size, d = 1.3; P < .001) and increased IL-6 (effect size, d = 1.1; P < .001) and TNF-α (effect size, d = 1.7; P < .001) gene expression levels when compared with controls, as well as higher levels of psychosocial stressors. A linear regression analysis in patients showed that a history of childhood trauma and high levels of recent stressors predicted lower BDNF expression through an inflammation-mediated pathway (adjusted R(2) = 0.23, P = .009). In turn, lower BDNF expression, increased IL-6 expression, and increased cortisol levels all significantly and independently predicted a smaller left hippocampal volume (adjusted R(2) = 0.71, P < .001). Biological changes activated by stress represent a significant factor influencing brain structure and function in first-episode psychosis through an effect on BDNF. © Copyright 2011 Physicians Postgraduate Press, Inc.

Religious burning as a potential major source of atmospheric fine aerosols in summertime Lhasa on the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Cui, Yu Yan; Liu, Shang; Bai, Zhixuan; Bian, Jianchun; Li, Dan; Fan, Kaiyu; McKeen, Stuart A.; Watts, Laurel A.; Ciciora, Steven J.; Gao, Ru-Shan

2018-05-01

We carried out field measurements of aerosols in Lhasa, a major city in the Tibetan Plateau that has been experiencing fast urbanization and industrialization. Aerosol number size distribution was continuously measured using an optical particle size spectrometer near the center of Lhasa city during the Asian summer monsoon season in 2016. The mass concentration of fine particles was modulated by boundary layer dynamics, with an average of 11 μg m-3 and the high values exceeding 50 μg m-3 during religious holidays. Daytime high concentration coincided with the religious burning of biomass and incense in the temples during morning hours, which produced heavy smoke. Factor analysis revealed a factor that likely represented religious burning. The factor contributed 34% of the campaign-average fine particle mass and the contribution reached up to 80% during religious holidays. The mass size distribution of aerosols produced from religious burnings peaked at ∼500 nm, indicating that these particles could efficiently decrease visibility and promote health risk. Because of its significance, our results suggest that further studies of religious burning, a currently under-studied source, are needed in the Tibetan Plateau and in other regions of the world where religious burnings are frequently practiced.

Automatic numerical-spatial association in synaesthesia: An fMRI investigation.

PubMed

Arend, Isabel; Ashkenazi, Sarit; Yuen, Kenneth; Ofir, Shiran; Henik, Avishai

2017-01-27

A horizontal mental number line (MNL) is used to describe how quantities are represented across space. In humans, the neural correlates associated with such a representation are found in different areas of the posterior parietal cortex, especially, the intraparietal sulcus (IPS). In a phenomenon known as number-space synaesthesia, individuals visualise numbers in specific spatial locations. The experience of a MNL for number-space synaesthetes is explicit, idiosyncratic, and highly stable over time. It remains an open question whether the mechanisms underlying numerical-spatial association are shared by synaesthetes and nonsynaesthetes. We address the neural correlates of number-space association by examining the brain response in a number-space synaestheste (MkM) whose MNL differs dramatically in its ordinality and direction from that of a control group. MkM and 15 nonsynaesthetes compared the physical size of two numbers, while ignoring their numerical value, during an event-related functional magnetic resonance imaging session (fMRI). Two factors were analysed: the numerical distance effect (NDE; e.g., 2-4 small distance vs. 1-6 large distance), and the size congruity effect (e.g., 2-8 congruent vs. 2-8 incongruent). Only for MkM, the NDE elicited significant activity in the left and right IPS, supramarginal gyrus (bilateral), and in the left angular gyrus. These results strongly support the role of the parietal cortex in the automatic coding of space and quantity in number-space synaesthesia, even when numerical values are task-irrelevant. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Prognostic factors of early breast cancer].

PubMed

Almagro, Elena; González, Cynthia S; Espinosa, Enrique

2016-02-19

Decision about the administration of adjuvant therapy for early breast cancer depends on the evaluation of prognostic factors. Lymph node status, tumor size and grade of differentiation are classical variables in this regard, and can be complemented by hormonal receptor status and HER2 expression. These factors can be combined into prognostic indexes to better estimate the risk of relapse or death. Other factors are less important. Gene profiles have emerged in recent years to identify low-risk patients who can forgo adjuvant chemotherapy. A number of profiles are available and can be used in selected cases. In the future, gene profiling will be used to select patients for treatment with new targeted therapies. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

The determination of the real nano-scale sizes of bacteria in chernozem during microbial succession by means of hatching of a soil in aerobic and anaerobic conditions

NASA Astrophysics Data System (ADS)

Gorbacheva, M.

2012-04-01

M.A. Gorbacheva,L.M. Polyanskaya The Faculty of Soil Science, Moscow State University, Leninskie Gory, GSP-1, Moscow,119991,Russia In recent years there's been particular attention paid to the smallest life's forms- bacteria which size can be measured in nanometer. These are the forms of bacteria with diameter of 5-200 nm. Theoretical calculations based on the content of the minimum number of DNA, enzyme, lipids in and ribosome in cells indicates impossibility of existence of a living cells within diameter less than 300 nm. It is theoretically possible for a living cell to exist within possible diameter of approximately 140 nm. Using a fluorescence microscope there's been indicated in a number of samples from lakes, rivers, soil, snow and rain water that 200 nm is the smallest diameter of a living cell. Supposingly, such a small size of bacteria in soil is determined by natural conditions which limit their development by nutritious substances and stress-factors. Rejuvenescence of nanobacteria under unfavourable natural conditions and stress-factors is studied in laboratory environment. The object of the current study has become the samples of typical arable chernozem of the Central Chernozem State Biosphere Reserve in Kursk. The detailed morphological description of the soil profile and its basic analytical characteristics are widely represented in scientific publications. The soil is characterized by a high carbon content which makes up 3,96% ,3,8% , and 2,9% for the upper layers of the A horizon, and 0,79% for the layer of the B horizon. A microbial succession was studied under aerobic and anaerobic conditions by means of experiments with microcosms in upper A horizons and B horizon of a chernozem. The final aim is to identify the cells size of bacteria in aerobic and anaerobic soil conditions in chernozem during the microbial succession, by dampening and application of chitin by means of «cascade filtration» method. The study of the microcosms is important for understanding natural mechanisms in soil and will be useful for the development of new soil models in laboratory. Thus, by means of «cascade filtration» method there've been made some results on true size, quantity and biomass of bacteria. Development of a bacteria in various soil horizons and their layers in aerobic and anaerobic conditions and calculations of biomass of bacteria in upper layer horizon A and lower layer horizon B have also become the subjects of the studies. It was identified that the quantity of bacteria in aerobic conditions increase during the microbial succession while bacteria sized 230 and 380 nm were dominating. In anaerobic conditions the process of connecting cells sized 170 nm and bacteria is observed. Biomass of bacteria is higher in anaerobic conditions in upper layer horizon A because of elevated variety of bacteria. In horizon B in anaerobic conditions it is of maximum because of anaerobic situation in situ. Thus, distribution of bacteria's size depends on aeration of soil. That helps to acknowledge the receipt of theory of a great number of researchers about that fact that the size of bacteria in the soil in anaerobic conditions decrease under stress-factors. This work touches upon such a poorly investigated subject as nanobacteria in the soil. But this knowledge plays a significant role in land reclamation oil-cut and prognostication pollution of the soil by pathogenic bacteria.

Variation in working memory capacity, fluid intelligence, and episodic recall: a latent variable examination of differences in the dynamics of free recall.

PubMed

Unsworth, Nash

2009-09-01

A latent variable analysis was conducted to examine the nature of individual differences in the dynamics of free recall and cognitive abilities. Participants performed multiple measures of free recall, working memory capacity (WMC), and fluid intelligence (gF). For each free recall task, recall accuracy, recall latency, and number of intrusion errors were determined, and latent factors were derived for each. It was found that recall accuracy was negatively related to both recall latency and number of intrusions, and recall latency and number of intrusions were positively related. Furthermore, latent WMC and gF factors were positively related to recall accuracy, but negatively related to recall latency and number of intrusions. Finally, a cluster analysis revealed that subgroups of participants with deficits in focusing the search had deficits in recovering degraded representations or deficits in monitoring the products of retrieval. The results are consistent with the idea that variation in the dynamics of free recall, WMC, and gF are primarily due to differences in search set size, but differences in recovery and monitoring are also important.

Dogs Have the Most Neurons, Though Not the Largest Brain: Trade-Off between Body Mass and Number of Neurons in the Cerebral Cortex of Large Carnivoran Species

PubMed Central

Jardim-Messeder, Débora; Lambert, Kelly; Noctor, Stephen; Pestana, Fernanda M.; de Castro Leal, Maria E.; Bertelsen, Mads F.; Alagaili, Abdulaziz N.; Mohammad, Osama B.; Manger, Paul R.; Herculano-Houzel, Suzana

2017-01-01

Carnivorans are a diverse group of mammals that includes carnivorous, omnivorous and herbivorous, domesticated and wild species, with a large range of brain sizes. Carnivory is one of several factors expected to be cognitively demanding for carnivorans due to a requirement to outsmart larger prey. On the other hand, large carnivoran species have high hunting costs and unreliable feeding patterns, which, given the high metabolic cost of brain neurons, might put them at risk of metabolic constraints regarding how many brain neurons they can afford, especially in the cerebral cortex. For a given cortical size, do carnivoran species have more cortical neurons than the herbivorous species they prey upon? We find they do not; carnivorans (cat, mongoose, dog, hyena, lion) share with non-primates, including artiodactyls (the typical prey of large carnivorans), roughly the same relationship between cortical mass and number of neurons, which suggests that carnivorans are subject to the same evolutionary scaling rules as other non-primate clades. However, there are a few important exceptions. Carnivorans stand out in that the usual relationship between larger body, larger cortical mass and larger number of cortical neurons only applies to small and medium-sized species, and not beyond dogs: we find that the golden retriever dog has more cortical neurons than the striped hyena, African lion and even brown bear, even though the latter species have up to three times larger cortices than dogs. Remarkably, the brown bear cerebral cortex, the largest examined, only has as many neurons as the ten times smaller cat cerebral cortex, although it does have the expected ten times as many non-neuronal cells in the cerebral cortex compared to the cat. We also find that raccoons have dog-like numbers of neurons in their cat-sized brain, which makes them comparable to primates in neuronal density. Comparison of domestic and wild species suggests that the neuronal composition of carnivoran brains is not affected by domestication. Instead, large carnivorans appear to be particularly vulnerable to metabolic constraints that impose a trade-off between body size and number of cortical neurons. PMID:29311850

Dogs Have the Most Neurons, Though Not the Largest Brain: Trade-Off between Body Mass and Number of Neurons in the Cerebral Cortex of Large Carnivoran Species.

PubMed

Jardim-Messeder, Débora; Lambert, Kelly; Noctor, Stephen; Pestana, Fernanda M; de Castro Leal, Maria E; Bertelsen, Mads F; Alagaili, Abdulaziz N; Mohammad, Osama B; Manger, Paul R; Herculano-Houzel, Suzana

2017-01-01

Carnivorans are a diverse group of mammals that includes carnivorous, omnivorous and herbivorous, domesticated and wild species, with a large range of brain sizes. Carnivory is one of several factors expected to be cognitively demanding for carnivorans due to a requirement to outsmart larger prey. On the other hand, large carnivoran species have high hunting costs and unreliable feeding patterns, which, given the high metabolic cost of brain neurons, might put them at risk of metabolic constraints regarding how many brain neurons they can afford, especially in the cerebral cortex. For a given cortical size, do carnivoran species have more cortical neurons than the herbivorous species they prey upon? We find they do not; carnivorans (cat, mongoose, dog, hyena, lion) share with non-primates, including artiodactyls (the typical prey of large carnivorans), roughly the same relationship between cortical mass and number of neurons, which suggests that carnivorans are subject to the same evolutionary scaling rules as other non-primate clades. However, there are a few important exceptions. Carnivorans stand out in that the usual relationship between larger body, larger cortical mass and larger number of cortical neurons only applies to small and medium-sized species, and not beyond dogs: we find that the golden retriever dog has more cortical neurons than the striped hyena, African lion and even brown bear, even though the latter species have up to three times larger cortices than dogs. Remarkably, the brown bear cerebral cortex, the largest examined, only has as many neurons as the ten times smaller cat cerebral cortex, although it does have the expected ten times as many non-neuronal cells in the cerebral cortex compared to the cat. We also find that raccoons have dog-like numbers of neurons in their cat-sized brain, which makes them comparable to primates in neuronal density. Comparison of domestic and wild species suggests that the neuronal composition of carnivoran brains is not affected by domestication. Instead, large carnivorans appear to be particularly vulnerable to metabolic constraints that impose a trade-off between body size and number of cortical neurons.

Factors affecting first return to work following a compensable occupational back injury.

PubMed

Oleinick, A; Gluck, J V; Guire, K

1996-11-01

Occupational back injuries produced $27 billion in direct and indirect costs in 1988. Predictors of prolonged disability have generally been identified in selected clinical populations, but there have been few population-based studies using statewide registries from workers' compensation systems. This study uses a 1986 cohort of 8,628 Michigan workers with compensable back injuries followed to March 1, 1990. Cox proportional hazards analyses with nine categorical covariates identified factors predicting missed worktime for the first disability episode following the injury. The model distinguished factors affecting the acute (< or = 8 weeks) and chronic disability periods (> 8 weeks). The first disability episode following injury contains 69.6% of the missed worktime observed through follow-up. In the acute phase, which contributes 15.2% of first episode missed worktime, gender, age, number of dependents, industry (construction), occupation, and type of accident predict continued work disability. Marital status, weekly wage compensation rate, and establishment size do not. Beyond 8 weeks, age, establishment size and, to a lesser degree, wage compensation rate predict duration of work disability. Graphs show the predicted disability course for injured workers with specific covariate patterns. Future efforts to reduce missed worktime may require modifications in current clinical practice by patient age group and the development of new strategies to encourage small and medium-size employers to find ways to return their injured employees to work sooner. Recent federal statutes covering disabled workers will only partially correct the strong effect of employer establishment size.

Semi-implicit iterative methods for low Mach number turbulent reacting flows: Operator splitting versus approximate factorization

NASA Astrophysics Data System (ADS)

MacArt, Jonathan F.; Mueller, Michael E.

2016-12-01

Two formally second-order accurate, semi-implicit, iterative methods for the solution of scalar transport-reaction equations are developed for Direct Numerical Simulation (DNS) of low Mach number turbulent reacting flows. The first is a monolithic scheme based on a linearly implicit midpoint method utilizing an approximately factorized exact Jacobian of the transport and reaction operators. The second is an operator splitting scheme based on the Strang splitting approach. The accuracy properties of these schemes, as well as their stability, cost, and the effect of chemical mechanism size on relative performance, are assessed in two one-dimensional test configurations comprising an unsteady premixed flame and an unsteady nonpremixed ignition, which have substantially different Damköhler numbers and relative stiffness of transport to chemistry. All schemes demonstrate their formal order of accuracy in the fully-coupled convergence tests. Compared to a (non-)factorized scheme with a diagonal approximation to the chemical Jacobian, the monolithic, factorized scheme using the exact chemical Jacobian is shown to be both more stable and more economical. This is due to an improved convergence rate of the iterative procedure, and the difference between the two schemes in convergence rate grows as the time step increases. The stability properties of the Strang splitting scheme are demonstrated to outpace those of Lie splitting and monolithic schemes in simulations at high Damköhler number; however, in this regime, the monolithic scheme using the approximately factorized exact Jacobian is found to be the most economical at practical CFL numbers. The performance of the schemes is further evaluated in a simulation of a three-dimensional, spatially evolving, turbulent nonpremixed planar jet flame.

Trophic strategies, animal diversity and body size

USGS Publications Warehouse

Lafferty, Kevin D.; Kuris, Armand M.

2002-01-01

A primary difference between predators and parasites is the number of victims that an individual attacks throughout a life-history stage. A key division within natural enemies is whether a successful attack eliminates the fitness of the prey or the host. A third distinctive axis for parasites is whether the host must die to further parasite development. The presence or absence of intensity-dependent pathology is a fourth factor that separates macroparasites from microparasites; this also distinguishes between social and solitary predators. Combining these four dichotomies defines seven types of parasitism, seven corresponding parasites, three forms of predation and, when one considers obligate and facultative combinations of these forms, four types of predator. Here, we argue that the energetics underlying the relative and absolute sizes of natural enemies and their victims is the primary selective factor responsible for the evolution of these different trophic strategies.

Selection of rolling-element bearing steels for long-life applications

NASA Technical Reports Server (NTRS)

Zaretsky, Erwin V.

1989-01-01

Nearly four decades of research in bearing steel metallurgy and processing have resulted in improvements in bearing life by a factor of 100 over that obtained in the early 1940s. For critical applications such as aircraft, these improvements have resulted in longer lived, more reliable commercial aircraft engines. Material factors such as hardness, retained austenite, grain size and carbide size, number, and area can influence rolling-element fatigue life. Bearing steel processing such as double vacuum melting can have a greater effect on bearing life than material chemistry. The selection and specification of a bearing steel is dependent on the integration of all these considerations into the bearing design and application. The paper reviews rolling-element fatigue data and analysis which can enable the engineer or metallurgist to select a rolling-element bearing steel for critical applications where long life is required.

Selection of rolling-element bearing steels for long-life application

NASA Technical Reports Server (NTRS)

Zaretsky, E. V.

1986-01-01

Nearly four decades of research in bearing steel metallurgy and processing have resulted in improvements in bearing life by a factor of 100 over that obtained in the early 1940's. For critical applications such as aircraft, these improvements have resulted in longer lived, more reliable commercial aircraft engines. Material factors such as hardness, retained austenite, grain size and carbide size, number, and area can influence rolling-element fatigue life. Bearing steel processing such as double vacuum melting can have a greater efect on bearing life than material chemistry. The selection and specification of a bearing steel is dependent on the integration of all these considerations into the bearing design and application. The paper reviews rolling-element fatigue data and analysis which can enable the engineer or metallurgist to select a rolling-element bearing steel for critical applications where long life is required.

Effects of insulin-like growth factor 1 on pathologic processes in the cuprizone model of multiple sclerosis

NASA Astrophysics Data System (ADS)

Fedorishin, D.; Sorokina, I.; Tolstikova, T.; Akulov, A.; Glazacheva, V.; Nemirovich-Danchenko, N.; Khodanovich, M.; Yarnykh, V.

2017-08-01

The study aims to evaluate the effect of insulin-like growth factor 1 (IGF-1) on the demyelination and astrogliosis using the cuprizone murine model. Demyelination was induced in 14 adult male mice by 0.3% cuprizone in drinking water. Five animals from the cuprizone-treated group received subcutaneous injections of IGF-1. Seven animals were used as a control group. The extent of demyelination was evaluated as a decrease in the size of the corpus callosum on T2-weighted images that were received using an 11.7T animal MRI scanner. Brain sections were immunohistochemically stained for glial fibrillary acidic protein (GFAP), a marker of astrocytes. It was revealed that the cuprizone caused extensive demyelination and astroglyosis. IGF-1 treatment restored the size of the corpus callosum and the number of astrocytes in the corpus callosum and the anterior commissure to the control level.

The Determinants of Staff and Resident Activity in Residential Services for People with Severe Intellectual Disability: Moving beyond Size, Building Design, Location and Number of Staff.

ERIC Educational Resources Information Center

Felce, David

1998-01-01

Draws together the results of seven studies that investigated factors influencing the effects of service quality in community-based residential services for people with severe mental retardation. Results found that quality of staff and resident activity is dependent on an interaction between the structure, orientation, and procedures followed…

Why Did a U.S. Secondary School District Retain Teacher-Librarians in a Time of Economic Crisis? A Case Study

ERIC Educational Resources Information Center

Ewbank, Ann Dutton

2010-01-01

The number of U.S. teacher-librarians has greatly diminished despite advocacy efforts by stakeholders. This case study investigated the factors that led governing board members in a mid-sized urban high school district to retain certified teacher-librarian positions despite a major economic crisis. Themes constructed through the analysis were:…

Nongenetic risk factors for holoprosencephaly: An updated review of the epidemiologic literature.

PubMed

Summers, April D; Reefhuis, Jennita; Taliano, Joanna; Rasmussen, Sonja A

2018-05-15

Holoprosencephaly (HPE) is a major structural birth defect of the brain that occurs in approximately 1 in 10,000 live births. Although some genetic causes of HPE are known, a substantial proportion of cases have an unknown etiology. Due to the low birth prevalence and rarity of exposure to many potential risk factors for HPE, few epidemiologic studies have had sufficient sample size to examine risk factors. A 2010 review of the literature identified several risk factors that had been consistently identified as occurring more frequently among cases of HPE, including maternal diabetes, twinning, and a predominance of females, while also identifying a number of potential risk factors that had been less widely studied. In this article, we summarize a systematic literature review conducted to update the evidence for nongenetic risk factors for HPE. © 2018 Wiley Periodicals, Inc.

gone early, a Novel Germline Factor, Ensures the Proper Size of the Stem Cell Precursor Pool in the Drosophila Ovary

PubMed Central

Matsuoka, Shinya; Gupta, Swati; Suzuki, Emiko; Hiromi, Yasushi; Asaoka, Miho

2014-01-01

In order to sustain lifelong production of gametes, many animals have evolved a stem cell–based gametogenic program. In the Drosophila ovary, germline stem cells (GSCs) arise from a pool of primordial germ cells (PGCs) that remain undifferentiated even after gametogenesis has initiated. The decision of PGCs to differentiate or remain undifferentiated is regulated by somatic stromal cells: specifically, epidermal growth factor receptor (EGFR) signaling activated in the stromal cells determines the fraction of germ cells that remain undifferentiated by shaping a Decapentaplegic (Dpp) gradient that represses PGC differentiation. However, little is known about the contribution of germ cells to this process. Here we show that a novel germline factor, Gone early (Goe), limits the fraction of PGCs that initiate gametogenesis. goe encodes a non-peptidase homologue of the Neprilysin family metalloendopeptidases. At the onset of gametogenesis, Goe was localized on the germ cell membrane in the ovary, suggesting that it functions in a peptidase-independent manner in cell–cell communication at the cell surface. Overexpression of Goe in the germline decreased the number of PGCs that enter the gametogenic pathway, thereby increasing the proportion of undifferentiated PGCs. Inversely, depletion of Goe increased the number of PGCs initiating differentiation. Excess PGC differentiation in the goe mutant was augmented by halving the dose of argos, a somatically expressed inhibitor of EGFR signaling. This increase in PGC differentiation resulted in a massive decrease in the number of undifferentiated PGCs, and ultimately led to insufficient formation of GSCs. Thus, acting cooperatively with a somatic regulator of EGFR signaling, the germline factor goe plays a critical role in securing the proper size of the GSC precursor pool. Because goe can suppress EGFR signaling activity and is expressed in EGF-producing cells in various tissues, goe may function by attenuating EGFR signaling, and thereby affecting the stromal environment. PMID:25420147

Performance of the University of Denver Low Turbulence, Airborne Aerosol Inlet in ACE-Asia

NASA Astrophysics Data System (ADS)

Lafleur, B.; Wilson, J. C.; Seebaugh, W. R.; Gesler, D.; Hilbert, H.; Mullen, J.; Reeves, J. M.

2002-12-01

The University of Denver Low Turbulence Inlet (DULTI) was flown on the NCAR C-130 in ACE-Asia. This inlet delivered large sample flows at velocities of a few meters per second at the exit of the inlet. This flow was slowed from the true air speed of the aircraft (100 to 150 m/s) to a few meters per second in a short diffuser with porous walls. The flow in the diffusing section was laminar. The automatic control system kept the inlet operating at near isokinetic intake velocities and in laminar flow for nearly all the flight time. The DULTI permits super micron particles to be sampled and delivered with high efficiency to the interior of the aircraft where they can be measured or collected. Because most of the air entering the inlet is removed through the porous medium, the sample flow experiences inertial enhancements. Because these enhancements occur in laminar flow, they are calculable using FLUENT. Enhancement factors are defined as the ratio of the number of particles of a given size per unit mass of air in the sample to the number of particles of that size per unit mass of air in the ambient. Experimenters divide measured mixing ratios of the aerosol by the enhancement factor to get the ambient mixing ratio of the particles. The diffuser used in ACE-Asia differed from that used in PELTI (2000), TexAQS2000 (2000) and ITCT (2002). In this poster, the flow parameters measured in the inlet in flight are compared with those calculated from FLUENT. And enhancement factors are presented for flight conditions. The enhancement factors are found to depend upon the Stokes number of particles in the entrance to the inlet and the ratio of the mass flow rate of air removed by suction to the mass flow rate delivered as sample.

Particle and gaseous emissions from individual diesel and CNG buses

NASA Astrophysics Data System (ADS)

Hallquist, Å. M.; Jerksjö, M.; Fallgren, H.; Westerlund, J.; Sjödin, Å.

2012-10-01

In this study size-resolved particle and gaseous emissions from 28 individual diesel-fuelled and 7 compressed natural gas (CNG)-fuelled buses, selected from an in-use bus fleet, were characterised for real-world dilution scenarios. The method used was based on using CO2 as a tracer of exhaust gas dilution. The particles were sampled by using an extractive sampling method and analysed with high time resolution instrumentation EEPS (10 Hz) and CO2 with non-dispersive infrared gas analyser (LI-840, LI-COR Inc. 1 Hz). The gaseous constituents (CO, HC and NO) were measured by using a remote sensing device (AccuScan RSD 3000, Environmental System Products Inc.). Nitrogen oxides, NOx, were estimated from NO by using default NO2/NOx ratios from the road vehicle emission model HBEFA 3.1. The buses studied were diesel-fuelled Euro II-V and CNG-fuelled Enhanced Environmental Friendly Vehicles (EEVs) with different after-treatment, including selective catalytic reduction (SCR), exhaust gas recirculation (EGR) and with and without diesel particulate filter (DPF). The primary driving mode applied in this study was accelerating mode. However, regarding the particle emissions also a constant speed mode was analysed. The investigated CNG buses emitted on average higher number of particles but less mass compared to the diesel-fuelled buses. Emission factors for number of particles (EFPN) were EFPN, DPF = 8.0 ± 3.1 × 1014, EFPN, no DPF =2.8 ± 1.6 × 1015 and EFPN, CNG = 7.8 ± 5.7 × 1015 (kg fuel-1). In the accelerating mode size-resolved EFs showed unimodal number size distributions with peak diameters of 70-90 nm and 10 nm for diesel and CNG buses, respectively. For the constant speed mode bimodal average number size distributions were obtained for the diesel buses with peak modes of ~10 nm and ~60 nm. Emission factors for NOx expressed as NO2 equivalents for the diesel buses were on average 27 ± 7 g (kg fuel)-1 and for the CNG buses 41 ± 26 g (kg fuel)-1. An anti-relationship between EFNOx and EFPM was observed especially for buses with no DPF and there was a positive relationship between EFPM and EFCO.

A giant on the ground: another large-bodied Atractus (Serpentes: Dipsadinae) from Ecuadorian Andes, with comments on the dietary specializations of the goo-eaters snakes.

PubMed

Passos, Paulo; Scanferla, Agustín; Melo-Sampaio, Paulo R; Brito, Jorge; Almendariz, Ana

2018-05-17

Body-size is significantly correlated with the number of vertebrae (pleomerism) in multiple vertebrate lineages, indicating that somitogenesis process is an important factor dictating evolutionary change associated to phyletic allometry and, consequently, species fitness and diversification. However, the role of the evolution of extreme body sizes (dwarfism and gigantism) remains elusive in snakes, mainly with respect to postnatal ontogeny in dietary preferences associated with evolution of gigantism in many lineages. We described herein a new species in the highly diversified and species-rich genus Atractus on the basis of four specimens from the southeastern slopes of the Ecuadorian Andes. The new species is morphologically similar and apparently closely related to two other allopatric giant congeners (A. gigas and A. touzeti), from which it can be distinguished by their distinct dorsal and ventral coloration, the number of supralabial and infralabial scales, the number of maxillary teeth, and relative width of the head. In addition, we discuss on the ontogenetic trajectories hypotheses and dietary specializations related to evolution of gigantism in the goo-eaters genus Atractus.

An improved optimization algorithm and Bayes factor termination criterion for sequential projection pursuit

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

Webb-Robertson, Bobbie-Jo M.; Jarman, Kristin H.; Harvey, Scott D.

2005-05-28

A fundamental problem in analysis of highly multivariate spectral or chromatographic data is reduction of dimensionality. Principal components analysis (PCA), concerned with explaining the variance-covariance structure of the data, is a commonly used approach to dimension reduction. Recently an attractive alternative to PCA, sequential projection pursuit (SPP), has been introduced. Designed to elicit clustering tendencies in the data, SPP may be more appropriate when performing clustering or classification analysis. However, the existing genetic algorithm (GA) implementation of SPP has two shortcomings, computation time and inability to determine the number of factors necessary to explain the majority of the structure inmore » the data. We address both these shortcomings. First, we introduce a new SPP algorithm, a random scan sampling algorithm (RSSA), that significantly reduces computation time. We compare the computational burden of the RSS and GA implementation for SPP on a dataset containing Raman spectra of twelve organic compounds. Second, we propose a Bayes factor criterion, BFC, as an effective measure for selecting the number of factors needed to explain the majority of the structure in the data. We compare SPP to PCA on two datasets varying in type, size, and difficulty; in both cases SPP achieves a higher accuracy with a lower number of latent variables.« less

Estimation of the emission factors of particle number and mass fractions from traffic at a site where mean vehicle speeds vary over short distances

NASA Astrophysics Data System (ADS)

Jones, Alan M.; Harrison, Roy M.

Emission factors for particle number in three size ranges (11-30; 30-100 and >100 nm) as well as for PM 2.5, PM 2.5-10 and PM 10 mass have been estimated separately for heavy and light-duty vehicles in a heavily trafficked street canyon in London where traffic speeds vary considerably over short distances. Emissions of NO x were estimated from published emission factors, and emissions of other pollutants estimated from their ratio to NO x in the roadside concentration after subtraction of the simultaneously measured urban background. The estimated emission factors are compared with other published data. Despite many differences in the design and implementation of the various studies, the results for particulate matter are broadly similar. Estimates of particle number emissions in this study for light-duty vehicles are very close to other published data, whilst those for heavy-duty vehicles are lower than in the more comparable studies. It is suggested that a contributory factor may be the introduction of diesel particle oxidation traps on some of the bus fleet in London. Estimates of emission factors for particle mass (PM 2.5 and PM 2.5-10) are within the range of other published data, and total mass emissions estimated from the ratio of concentration to NO x are tolerably close to those estimated using emission factors from the National Atmospheric Emissions Inventory (NAEI). However, the method leads to an estimate of carbon monoxide emissions 3-6 times larger than that derived using the NAEI factors.

Importance of recurrence rating, morphology, hernial gap size, and risk factors in ventral and incisional hernia classification.

PubMed

Dietz, U A; Winkler, M S; Härtel, R W; Fleischhacker, A; Wiegering, A; Isbert, C; Jurowich, Ch; Heuschmann, P; Germer, C-T

2014-02-01

There is limited evidence on the natural course of ventral and incisional hernias and the results of hernia repair, what might partially be explained by the lack of an accepted classification system. The aim of the present study is to investigate the association of the criteria included in the Wuerzburg classification system of ventral and incisional hernias with postoperative complications and long-term recurrence. In a retrospective cohort study, the data on 330 consecutive patients who underwent surgery to repair ventral and incisional hernias were analyzed. The following four classification criteria were applied: (a) recurrence rating (ventral, incisional or incisional recurrent); (b) morphology (location); (c) size of the hernial gap; and (d) risk factors. The primary endpoint was the occurrence of a recurrence during follow-up. Secondary endpoints were incidence of postoperative complications. Independent association between classification criteria, type of surgical procedures and postoperative complications was calculated by multivariate logistic regression analysis and between classification criteria, type of surgical procedures and risk of long-term recurrence by Cox regression analysis. Follow-up lasted a mean 47.7 ± 23.53 months (median 45 months) or 3.9 ± 1.96 years. The criterion "recurrence rating" was found as predictive factor for postoperative complications in the multivariate analysis (OR 2.04; 95 % CI 1.09-3.84; incisional vs. ventral hernia). The criterion "morphology" had influence neither on the incidence of the critical event "recurrence during follow-up" nor on the incidence of postoperative complications. Hernial gap "width" predicted postoperative complications in the multivariate analysis (OR 1.98; 95 % CI 1.19-3.29; ≤5 vs. >5 cm). Length of the hernial gap was found to be an independent prognostic factor for the critical event "recurrence during follow-up" (HR 2.05; 95 % CI 1.25-3.37; ≤5 vs. >5 cm). The presence of 3 or more risk factors was a consistent predictor for "recurrence during follow-up" (HR 2.25; 95 % CI 1.28-9.92). Mesh repair was an independent protective factor for "recurrence during follow-up" compared to suture (HR 0.53; 95 % CI 0.32-0.86). The ventral and incisional hernia classification of Dietz et al. employs a clinically proven terminology and has an open classification structure. Hernial gap size and the number of risk factors are independent predictors for "recurrence during follow-up", whereas recurrence rating and hernial gap size correlated significantly with the incidence of postoperative complications. We propose the application of these criteria for future clinical research, as larger patient numbers will be needed to refine the results.

Tbx15 controls skeletal muscle fibre-type determination and muscle metabolism

PubMed Central

Lee, Kevin Y.; Singh, Manvendra K.; Ussar, Siegfried; Wetzel, Petra; Hirshman, Michael F.; Goodyear, Laurie J.; Kispert, Andreas; Kahn, C. Ronald

2015-01-01

Skeletal muscle is composed of both slow-twitch oxidative myofibers and fast-twitch glycolytic myofibers that differentially impact muscle metabolism, function and eventually whole-body physiology. Here we show that the mesodermal transcription factor T-box 15 (Tbx15) is highly and specifically expressed in glycolytic myofibers. Ablation of Tbx15 in vivo leads to a decrease in muscle size due to a decrease in the number of glycolytic fibres, associated with a small increase in the number of oxidative fibres. This shift in fibre composition results in muscles with slower myofiber contraction and relaxation, and also decreases whole-body oxygen consumption, reduces spontaneous activity, increases adiposity and glucose intolerance. Mechanistically, ablation of Tbx15 leads to activation of AMPK signalling and a decrease in Igf2 expression. Thus, Tbx15 is one of a limited number of transcription factors to be identified with a critical role in regulating glycolytic fibre identity and muscle metabolism. PMID:26299309

The changing food outlet distributions and local contextual factors in the United States

PubMed Central

2014-01-01

Background Little is known about the dynamics of the food outlet distributions associated with local contextual factors in the U.S. This study examines the changes in food stores/services at the 5-digit Zip Code Tabulated Area (ZCTA5) level in the U.S., and assesses contextual factors associated with the changes. Methods Data from 27,878 ZCTA5s in the contiguous United States without an extreme change in the number of 6 types of food stores/services (supermarkets, small-size grocery stores, convenience stores, fresh/specialty food markets, carry-out restaurants, and full-service restaurants) were used. ZCTA5s’ contextual factors were from the 2000 Census. Numbers of food stores/services were derived from the Census Business Pattern databases. Linear regression models assessed contextual factors’ influences (racial/ethnic compositions, poverty rate, urbanization level, and foreign-born population%) on 1-year changes in food stores/services during 2000–2001, adjusted for population size, total business change, and census regions. Results Small-size grocery stores and fresh/specialty food markets increased more and convenience stores decreased more in Hispanic-predominant than other areas. Among supermarket-free places, new supermarkets were less likely to be introduced into black-predominant than white-predominant areas (odds ratio (OR) = 0.52, 95% CI = 0.30-0.92). However, among areas without the following type of store at baseline, supermarket (OR = 0.48 (0.33-0.70)), small-size grocery stores (OR = 1.32 (1.08-1.62)), and fresh/specialty food markets (OR = 0.70 (0.53-0.92)) were less likely to be introduced into areas of low foreign-born population than into areas of high foreign-born population. Higher poverty rate was associated with a greater decrease in supermarket, a less decrease in small-size grocery stores, and a less increase in carry-out restaurants (all p for trends <0.001). Urban areas experienced more increases in full-service and carry-out restaurants than suburban areas. Conclusions Local area characteristics affect 1-year changes in food environment in the U.S. Hispanic population was associated with more food stores/services capable of supplying fresh food items. Black-predominant and poverty-afflicted areas had a greater decrease in supermarkets. Full-service and carry-out restaurants increased more in urban than suburban areas. Foreign-born population density was associated with introduction of grocery stores and fresh/specialty food markets into the areas. PMID:24433323

Novel method for on-road emission factor measurements using a plume capture trailer.

PubMed

Morawska, L; Ristovski, Z D; Johnson, G R; Jayaratne, E R; Mengersen, K

2007-01-15

The method outlined provides for emission factor measurements to be made for unmodified vehicles driving under real world conditions at minimal cost. The method consists of a plume capture trailer towed behind a test vehicle. The trailer collects a sample of the naturally diluted plume in a 200 L conductive bag and this is delivered immediately to a mobile laboratory for subsequent analysis of particulate and gaseous emissions. The method offers low test turnaround times with the potential to complete much larger numbers of emission factor measurements than have been possible using dynamometer testing. Samples can be collected at distances up to 3 m from the exhaust pipe allowing investigation of early dilution processes. Particle size distribution measurements, as well as particle number and mass emission factor measurements, based on naturally diluted plumes are presented. A dilution profile relating the plume dilution ratio to distance from the vehicle tail pipe for a diesel passenger vehicle is also presented. Such profiles are an essential input for new mechanistic roadway air quality models.

Sizes of lipid domains: What do we know from artificial lipid membranes? What are the possible shared features with membrane rafts in cells?

PubMed

Rosetti, Carla M; Mangiarotti, Agustín; Wilke, Natalia

2017-05-01

In model lipid membranes with phase coexistence, domain sizes distribute in a very wide range, from the nanometer (reported in vesicles and supported films) to the micrometer (observed in many model membranes). Domain growth by coalescence and Ostwald ripening is slow (minutes to hours), the domain size being correlated with the size of the capture region. Domain sizes thus strongly depend on the number of domains which, in the case of a nucleation process, depends on the oversaturation of the system, on line tension and on the perturbation rate in relation to the membrane dynamics. Here, an overview is given of the factors that affect nucleation or spinodal decomposition and domain growth, and their influence on the distribution of domain sizes in different model membranes is discussed. The parameters analyzed respond to very general physical rules, and we therefore propose a similar behavior for the rafts in the plasma membrane of cells, but with obstructed mobility and with a continuously changing environment. Copyright © 2017 Elsevier B.V. All rights reserved.

The empirical case against the ‘demographic turn’ in Palaeolithic archaeology

PubMed Central

Collard, Mark; Vaesen, Krist; Cosgrove, Richard; Roebroeks, Wil

2016-01-01

Recently, it has become commonplace to interpret major transitions and other patterns in the Palaeolithic archaeological record in terms of population size. Increases in cultural complexity are claimed to result from increases in population size; decreases in cultural complexity are suggested to be due to decreases in population size; and periods of no change are attributed to low numbers or frequent extirpation. In this paper, we argue that this approach is not defensible. We show that the available empirical evidence does not support the idea that cultural complexity in hunter–gatherers is governed by population size. Instead, ethnographic and archaeological data suggest that hunter–gatherer cultural complexity is most strongly influenced by environmental factors. Because all hominins were hunter–gatherers until the Holocene, this means using population size to interpret patterns in the Palaeolithic archaeological record is problematic. In future, the population size hypothesis should be viewed as one of several competing hypotheses and its predictions formally tested alongside those of its competitors. This article is part of the themed issue ‘Major transitions in human evolution’. PMID:27298472

The importance of plot size and the number of sampling seasons on capturing macrofungal species richness.

PubMed

Li, Huili; Ostermann, Anne; Karunarathna, Samantha C; Xu, Jianchu; Hyde, Kevin D; Mortimer, Peter E

2018-07-01

The species-area relationship is an important factor in the study of species diversity, conservation biology, and landscape ecology. A deeper understanding of this relationship is necessary, in order to provide recommendations on how to improve the quality of data collection on macrofungal diversity in different land use systems in future studies, a systematic assessment of methodological parameters, in particular optimal plot sizes. The species-area relationship of macrofungi in tropical and temperate climatic zones and four different land use systems were investigated by determining the macrofungal species richness in plot sizes ranging from 100 m 2 to 10 000 m 2 over two sampling seasons. We found that the effect of plot size on recorded species richness significantly differed between land use systems with the exception of monoculture systems. For both climate zones, land use system needs to be considered when determining optimal plot size. Using an optimal plot size was more important than temporal replication (over two sampling seasons) in accurately recording species richness. Copyright © 2018 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Combining waterfowl and breeding bird survey data to estimate wood duck breeding population size in the Atlantic Flyway

USGS Publications Warehouse

Guthrie Zimmerman,; Sauer, John; Fleming, Kathy; Link, William; Pamela R. Garrettson,

2015-01-01

We combined data from the Atlantic Flyway Breeding Waterfowl Survey (AFBWS) and the North American Breeding Bird Survey (BBS) to estimate the number of wood ducks (Aix sponsa) in the United States portion of the Atlantic Flyway from 1993 to 2013. The AFBWS is a plot-based survey that covers most of the northern and central portions of the Flyway; when analyzed with adjustments for survey time of day effects, these data can be used to estimate population size. The BBS provides an index of wood duck abundance along roadside routes. Although factors influencing change in BBS counts over time can be controlled in BBS analysis, BBS indices alone cannot be used to derive population size estimates. We used AFBWS data to scale BBS indices for Bird Conservation Regions (BCR), basing the scaling factors on the ratio of estimated AFBWS population sizes to regional BBS indices for portions of BCRs that were common to both surveys. We summed scaled BBS results for portions of the Flyway not covered by the AFBWS with AFBWS population estimates to estimate a mean yearly total of 1,295,875 (mean 95% CI: 1,013,940–1,727,922) wood ducks. Scaling factors varied among BCRs from 16.7 to 148.0; the mean scaling factor was 68.9 (mean 95% CI: 53.5–90.9). Flyway-wide, population estimates from the combined analysis were consistent with alternative estimates derived from harvest data, and also provide population estimates within states and BCRs. We recommend their use in harvest and habitat management within the Atlantic Flyway.

Particle behavior simulation in thermophoresis phenomena by direct simulation Monte Carlo method

NASA Astrophysics Data System (ADS)

Wada, Takao

2014-07-01

A particle motion considering thermophoretic force is simulated by using direct simulation Monte Carlo (DSMC) method. Thermophoresis phenomena, which occur for a particle size of 1 μm, are treated in this paper. The problem of thermophoresis simulation is computation time which is proportional to the collision frequency. Note that the time step interval becomes much small for the simulation considering the motion of large size particle. Thermophoretic forces calculated by DSMC method were reported, but the particle motion was not computed because of the small time step interval. In this paper, the molecule-particle collision model, which computes the collision between a particle and multi molecules in a collision event, is considered. The momentum transfer to the particle is computed with a collision weight factor, where the collision weight factor means the number of molecules colliding with a particle in a collision event. The large time step interval is adopted by considering the collision weight factor. Furthermore, the large time step interval is about million times longer than the conventional time step interval of the DSMC method when a particle size is 1 μm. Therefore, the computation time becomes about one-millionth. We simulate the graphite particle motion considering thermophoretic force by DSMC-Neutrals (Particle-PLUS neutral module) with above the collision weight factor, where DSMC-Neutrals is commercial software adopting DSMC method. The size and the shape of the particle are 1 μm and a sphere, respectively. The particle-particle collision is ignored. We compute the thermophoretic forces in Ar and H2 gases of a pressure range from 0.1 to 100 mTorr. The results agree well with Gallis' analytical results. Note that Gallis' analytical result for continuum limit is the same as Waldmann's result.

Exploring the Factor Structure of Neurocognitive Measures in Older Individuals

PubMed Central

Santos, Nadine Correia; Costa, Patrício Soares; Amorim, Liliana; Moreira, Pedro Silva; Cunha, Pedro; Cotter, Jorge; Sousa, Nuno

2015-01-01

Here we focus on factor analysis from a best practices point of view, by investigating the factor structure of neuropsychological tests and using the results obtained to illustrate on choosing a reasonable solution. The sample (n=1051 individuals) was randomly divided into two groups: one for exploratory factor analysis (EFA) and principal component analysis (PCA), to investigate the number of factors underlying the neurocognitive variables; the second to test the “best fit” model via confirmatory factor analysis (CFA). For the exploratory step, three extraction (maximum likelihood, principal axis factoring and principal components) and two rotation (orthogonal and oblique) methods were used. The analysis methodology allowed exploring how different cognitive/psychological tests correlated/discriminated between dimensions, indicating that to capture latent structures in similar sample sizes and measures, with approximately normal data distribution, reflective models with oblimin rotation might prove the most adequate. PMID:25880732

Utilization and farmers' knowledge on pigeonpea diversity in Benin, West Africa.

PubMed

Ayenan, Mathieu Anatole Tele; Danquah, Agyemang; Ahoton, Léonard Essehou; Ofori, Kwadwo

2017-06-20

Understanding factors driving farmers' uses of crop genetic resources is a key component not only to design appropriate conservation strategies but also to promote sustainable production. However, in Benin, limited information is available on farmers' knowledge related to pigeonpea uses and conservation. This study aimed at i) identifying and investigating the different uses of pigeonpea in relation with socio-cultural factors, namely age, gender, ethnic group and respondents' residence, ii) assessing pigeonpea varieties richness at household level and iii) evaluating the extent and distribution of pigeonpea varieties. Three hundred and two farmers were surveyed using structured questionnaire. Direct observation, field visit and focus group discussion were carried out. Association between number of varieties maintained at household level and socio-cultural variables was tested. Mann-Whitney test was used to assess whether the number of varieties held by households headed by men and women were different. Distribution and extent of diversity was assessed through four cells analysis. Farmers in Benin mainly grow pigeonpea for its grains for home consumption. Pigeonpea's stem and leaves are used for medicinal purposes to treat malaria, dizziness, measles, and eye infection. The ethnic group and the locality of residence of farmers influenced on the use of pigeonpea for medicinal purposes (P < 0.01). There was no significant association (P > 0.05) between the number of varieties held by household and the age of the respondent, number of years of experience in pigeonpea cultivation, the size of household, number of family members engaged in agricultural activities and gender. Farmers used criteria including seed colors, seed size, plant height, maturity groups and cooking time to classify their varieties. Varieties with white seed coat color were the most grown while varieties with black, red or mottled seed coat color are being abandoned and deserve to be conserved. Knowledge on medicinal uses of pigeonpea is vertically transmitted within community and pigeonpea varieties maintenance at household level does not depend on socio-cultural factors. This study will contribute to raise awareness on the various utilization of pigeonpea. In addition, it provides the basis for designing conservation strategies of pigeonpea genetic resources.

Models of epidemics: when contact repetition and clustering should be included

PubMed Central

Smieszek, Timo; Fiebig, Lena; Scholz, Roland W

2009-01-01

Background The spread of infectious disease is determined by biological factors, e.g. the duration of the infectious period, and social factors, e.g. the arrangement of potentially contagious contacts. Repetitiveness and clustering of contacts are known to be relevant factors influencing the transmission of droplet or contact transmitted diseases. However, we do not yet completely know under what conditions repetitiveness and clustering should be included for realistically modelling disease spread. Methods We compare two different types of individual-based models: One assumes random mixing without repetition of contacts, whereas the other assumes that the same contacts repeat day-by-day. The latter exists in two variants, with and without clustering. We systematically test and compare how the total size of an outbreak differs between these model types depending on the key parameters transmission probability, number of contacts per day, duration of the infectious period, different levels of clustering and varying proportions of repetitive contacts. Results The simulation runs under different parameter constellations provide the following results: The difference between both model types is highest for low numbers of contacts per day and low transmission probabilities. The number of contacts and the transmission probability have a higher influence on this difference than the duration of the infectious period. Even when only minor parts of the daily contacts are repetitive and clustered can there be relevant differences compared to a purely random mixing model. Conclusion We show that random mixing models provide acceptable estimates of the total outbreak size if the number of contacts per day is high or if the per-contact transmission probability is high, as seen in typical childhood diseases such as measles. In the case of very short infectious periods, for instance, as in Norovirus, models assuming repeating contacts will also behave similarly as random mixing models. If the number of daily contacts or the transmission probability is low, as assumed for MRSA or Ebola, particular consideration should be given to the actual structure of potentially contagious contacts when designing the model. PMID:19563624

Perinatal Medical Variables Predict Executive Function within a Sample of Preschoolers Born Very Low Birth Weight

PubMed Central

Duvall, Susanne W.; Erickson, Sarah J.; MacLean, Peggy; Lowe, Jean R.

2014-01-01

The goal was to identify perinatal predictors of early executive dysfunction in preschoolers born very low birth weight. Fifty-seven preschoolers completed three executive function tasks (Dimensional Change Card Sort-Separated (inhibition, working memory and cognitive flexibility), Bear Dragon (inhibition and working memory) and Gift Delay Open (inhibition)). Relationships between executive function and perinatal medical severity factors (gestational age, days on ventilation, size for gestational age, maternal steroids and number of surgeries), and chronological age were investigated by multiple linear regression and logistic regression. Different perinatal medical severity factors were predictive of executive function tasks, with gestational age predicting Bear Dragon and Gift Open; and number of surgeries and maternal steroids predicting performance on Dimensional Change Card Sort-Separated. By understanding the relationship between perinatal medical severity factors and preschool executive outcomes, we may be able to identify children at highest risk for future executive dysfunction, thereby focusing targeted early intervention services. PMID:25117418

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

Shim, Yunsic; Amar, Jacques G.

While temperature-accelerated dynamics (TAD) is a powerful method for carrying out non-equilibrium simulations of systems over extended time scales, the computational cost of serial TAD increases approximately as N{sup 3} where N is the number of atoms. In addition, although a parallel TAD method based on domain decomposition [Y. Shim et al., Phys. Rev. B 76, 205439 (2007)] has been shown to provide significantly improved scaling, the dynamics in such an approach is only approximate while the size of activated events is limited by the spatial decomposition size. Accordingly, it is of interest to develop methods to improve the scalingmore » of serial TAD. As a first step in understanding the factors which determine the scaling behavior, we first present results for the overall scaling of serial TAD and its components, which were obtained from simulations of Ag/Ag(100) growth and Ag/Ag(100) annealing, and compare with theoretical predictions. We then discuss two methods based on localization which may be used to address two of the primary “bottlenecks” to the scaling of serial TAD with system size. By implementing both of these methods, we find that for intermediate system-sizes, the scaling is improved by almost a factor of N{sup 1/2}. Some additional possible methods to improve the scaling of TAD are also discussed.« less

Improved scaling of temperature-accelerated dynamics using localization

NASA Astrophysics Data System (ADS)

Shim, Yunsic; Amar, Jacques G.

2016-07-01

While temperature-accelerated dynamics (TAD) is a powerful method for carrying out non-equilibrium simulations of systems over extended time scales, the computational cost of serial TAD increases approximately as N3 where N is the number of atoms. In addition, although a parallel TAD method based on domain decomposition [Y. Shim et al., Phys. Rev. B 76, 205439 (2007)] has been shown to provide significantly improved scaling, the dynamics in such an approach is only approximate while the size of activated events is limited by the spatial decomposition size. Accordingly, it is of interest to develop methods to improve the scaling of serial TAD. As a first step in understanding the factors which determine the scaling behavior, we first present results for the overall scaling of serial TAD and its components, which were obtained from simulations of Ag/Ag(100) growth and Ag/Ag(100) annealing, and compare with theoretical predictions. We then discuss two methods based on localization which may be used to address two of the primary "bottlenecks" to the scaling of serial TAD with system size. By implementing both of these methods, we find that for intermediate system-sizes, the scaling is improved by almost a factor of N1/2. Some additional possible methods to improve the scaling of TAD are also discussed.

Recent population size, trends, and limiting factors for the double-crested Cormorant in Western North America

USGS Publications Warehouse

Adkins, Jessica Y.; Roby, Daniel D.; Lyons, Donald E.; Courtot, Karen N.; Collis, Ken; Carter, Harry R.; Shuford, W. David; Capitolo, Phillip J.

2014-01-01

The status of the double-crested cormorant (Phalacrocorax auritus) in western North America was last evaluated during 1987–2003. In the interim, concern has grown over the potential impact of predation by double-crested cormorants on juvenile salmonids (Oncorhynchusspp.), particularly in the Columbia Basin and along the Pacific coast where some salmonids are listed for protection under the United States Endangered Species Act. Recent re-evaluations of double-crested cormorant management at the local, flyway, and federal level warrant further examination of the current population size and trends in western North America. We collected colony size data for the western population (British Columbia, Washington, Oregon, Idaho, California, Nevada, Utah, Arizona, and the portions of Montana, Wyoming, Colorado and New Mexico west of the Continental Divide) by conducting aircraft-, boat-, or ground-based surveys and by cooperating with government agencies, universities, and non-profit organizations. In 2009, we estimated approximately 31,200 breeding pairs in the western population. We estimated that cormorant numbers in the Pacific Region (British Columbia, Washington, Oregon, and California) increased 72% from 1987–1992 to circa 2009. Based on the best available data for this period, the average annual growth rate (λ) of the number of breeding birds in the Pacific Region was 1.03, versus 1.07 for the population east of the Continental Divide during recent decades. Most of the increase in the Pacific Region can be attributed to an increase in the size of the nesting colony on East Sand Island in the Columbia River estuary, which accounts for about 39% of all breeding pairs in the western population and is the largest known breeding colony for the species (12,087 breeding pairs estimated in 2009). In contrast, numbers of breeding pairs estimated in coastal British Columbia and Washington have declined by approximately 66% during this same period. Disturbance at breeding colonies by bald eagles (Haliaeetus leucocephalus) and humans are likely limiting factors on the growth of the western population at present. Because of differences in biology and management, the western population of double-crested cormorants warrants consideration as a separate management unit from the population east of the Continental Divide.

Stimuli Reduce the Dimensionality of Cortical Activity

PubMed Central

Mazzucato, Luca; Fontanini, Alfredo; La Camera, Giancarlo

2016-01-01

The activity of ensembles of simultaneously recorded neurons can be represented as a set of points in the space of firing rates. Even though the dimension of this space is equal to the ensemble size, neural activity can be effectively localized on smaller subspaces. The dimensionality of the neural space is an important determinant of the computational tasks supported by the neural activity. Here, we investigate the dimensionality of neural ensembles from the sensory cortex of alert rats during periods of ongoing (inter-trial) and stimulus-evoked activity. We find that dimensionality grows linearly with ensemble size, and grows significantly faster during ongoing activity compared to evoked activity. We explain these results using a spiking network model based on a clustered architecture. The model captures the difference in growth rate between ongoing and evoked activity and predicts a characteristic scaling with ensemble size that could be tested in high-density multi-electrode recordings. Moreover, we present a simple theory that predicts the existence of an upper bound on dimensionality. This upper bound is inversely proportional to the amount of pair-wise correlations and, compared to a homogeneous network without clusters, it is larger by a factor equal to the number of clusters. The empirical estimation of such bounds depends on the number and duration of trials and is well predicted by the theory. Together, these results provide a framework to analyze neural dimensionality in alert animals, its behavior under stimulus presentation, and its theoretical dependence on ensemble size, number of clusters, and correlations in spiking network models. PMID:26924968

Stimuli Reduce the Dimensionality of Cortical Activity.

PubMed

Mazzucato, Luca; Fontanini, Alfredo; La Camera, Giancarlo

2016-01-01

The activity of ensembles of simultaneously recorded neurons can be represented as a set of points in the space of firing rates. Even though the dimension of this space is equal to the ensemble size, neural activity can be effectively localized on smaller subspaces. The dimensionality of the neural space is an important determinant of the computational tasks supported by the neural activity. Here, we investigate the dimensionality of neural ensembles from the sensory cortex of alert rats during periods of ongoing (inter-trial) and stimulus-evoked activity. We find that dimensionality grows linearly with ensemble size, and grows significantly faster during ongoing activity compared to evoked activity. We explain these results using a spiking network model based on a clustered architecture. The model captures the difference in growth rate between ongoing and evoked activity and predicts a characteristic scaling with ensemble size that could be tested in high-density multi-electrode recordings. Moreover, we present a simple theory that predicts the existence of an upper bound on dimensionality. This upper bound is inversely proportional to the amount of pair-wise correlations and, compared to a homogeneous network without clusters, it is larger by a factor equal to the number of clusters. The empirical estimation of such bounds depends on the number and duration of trials and is well predicted by the theory. Together, these results provide a framework to analyze neural dimensionality in alert animals, its behavior under stimulus presentation, and its theoretical dependence on ensemble size, number of clusters, and correlations in spiking network models.

Clinical and histopathological factors associated with Ki-67 expression in breast cancer patients

PubMed Central

ALCO, GUL; BOZDOGAN, ATILLA; SELAMOGLU, DERYA; PILANCI, KEZBAN NUR; TUZLALI, SITKI; ORDU, CETIN; IGDEM, SEFIK; OKKAN, SAIT; DINCER, MAKTAV; DEMIR, GOKHAN; OZMEN, VAHIT

2015-01-01

The aim of the present study was to identify the optimal Ki-67 cut-off value in breast cancer (BC) patients, and investigate the association of Ki-67 expression levels with other prognostic factors. Firstly, a retrospective search was performed to identify patients with stage I–III BC (n=462). A range of Ki-67 index values were then assigned to five groups (<10, 10–14, 15–19, 20–24 and ≥25%). The correlation between the Ki-67 index and other prognostic factors [age, tumor type, histological and nuclear grade, tumor size, multifocality, an in situ component, lymphovascular invasion (LVI), estrogen and progesterone receptor (ER/PR) expression, human epidermal growth factor receptor (HER-2) status, axillary involvement and tumor stage] were investigated in each group. The median Ki-67 value was revealed to be 20% (range, 1–95%). A young age (≤40 years old), tumor type, size and grade, LVI, ER/PR negativity and HER-2 positivity were revealed to be associated with the Ki-67 level. Furthermore, Ki-67 was demonstrated to be negatively correlated with ER/PR expression (P<0.001), but positively correlated with tumor size (P<0.001). The multivariate analysis revealed that a Ki-67 value of ≥15% was associated with the largest number of poor prognostic factors (P=0.036). In addition, a Ki-67 value of ≥15% was identified to be statistically significant in association with certain luminal subtypes. The rate of disease-free survival was higher in patients with luminal A subtype BC (P=0.036). Following the correlation analysis for the Ki-67 index and the other prognostic factors, a Ki-67 value of ≥15% was revealed to be the optimal cut-off level for BC patients. PMID:25663855

Does Podcast Use Enhance Critical Thinking in Nursing Education?

PubMed

Blum, Cynthia A

The purpose of this pilot interventional study was to examine relationships between adjunctive podcast viewing and nursing students' critical thinking (CT) abilities. Participants were last semester/preceptorship nursing students. The intervention group was given unrestricted access to a CT podcast. There was no statistical significance between Health Sciences Reasoning Test pretest and posttest scores, the number of times the podcast was viewed, and specific demographic factors. The results suggest that CT podcast viewing did not improve CT abilities. However, Likert scale results indicated students liked this method of learning. Demographic factors and sample size were limited, and further research is recommended.

Congruences between modular forms: raising the level and dropping Euler factors.

PubMed

Diamond, F

1997-10-14

We discuss the relationship among certain generalizations of results of Hida, Ribet, and Wiles on congruences between modular forms. Hida's result accounts for congruences in terms of the value of an L-function, and Ribet's result is related to the behavior of the period that appears there. Wiles' theory leads to a class number formula relating the value of the L-function to the size of a Galois cohomology group. The behavior of the period is used to deduce that a formula at "nonminimal level" is obtained from one at "minimal level" by dropping Euler factors from the L-function.

Serial Tissue Expansion at the Same Site in Pediatric Patients: Is the Subsequent Expansion Faster?

PubMed Central

Lee, Moon Ki; Park, Seong Oh; Choi, Tae Hyun

2017-01-01

Background Serial tissue expansion is performed to remove giant congenital melanocytic nevi. However, there have been no studies comparing the expansion rate between the subsequent and preceding expansions. In this study, we analyzed the rate of expansion in accordance with the number of surgeries, expander location, expander size, and sex. Methods A retrospective analysis was performed in pediatric patients who underwent tissue expansion for giant congenital melanocytic nevi. We tested four factors that may influence the expansion rate: The number of surgeries, expander location, expander size, and sex. The rate of expansion was calculated by dividing the ‘inflation amount’ by the ‘expander size’. Results The expansion rate, compared with the first-time group, was 1.25 times higher in the second-or-more group (P=0.04) and 1.84 times higher in the third-or-more group (P<0.01). The expansion rate was higher at the trunk than at other sites (P<0.01). There was a tendency of lower expansion rate for larger expanders (P=0.03). Sex did not affect the expansion rate. Conclusions There was a positive correlation between the number of surgeries and the expansion rate, a positive correlation between the expander location and the expansion rate, and a negative correlation between the expander size and the expansion rate. PMID:29076319

Enhanced heat transfer and frictional losses in heat exchanger tube with modified helical coiled inserts

NASA Astrophysics Data System (ADS)

Verma, Aditya; Kumar, Manoj; Patil, Anil Kumar

2018-04-01

The application of compact heat exchangers in any thermal system improves overall performance with a considerable reduction in size and weight. Inserts of different geometrical features have been used as turbulence promoting devices to increase the heat transfer rates. The present study deals with the experimental investigation of heat transfer and fluid flow characteristics of a tubular heat exchanger fitted with modified helical coiled inserts. Experiments have been carried out for a smooth tube without insert, tube fitted with helical coiled inserts, and modified helical coiled inserts. The helical coiled inserts are tested by varying the pitch ratio and wire diameter ratio from 0.5-1.5, and 0.063-0.125, respectively for the Reynolds number range of 1400 to 11,000. Experimental data have also been collected for the modified helical coiled inserts with gradually increasing pitch (GIP) and gradually decreasing pitch (GDP) configurations. The Nusselt number and friction factor values for helical coiled inserts are enhanced in the range of 1.42-2.62, 3.4-27.4, relative to smooth tube, respectively. The modified helical coiled insert showed enhancements in Nusselt number and friction factor values in the range of 1.49-3.14, 11.2-19.9, relative to smooth tube, respectively. The helical coiled and modified helical coiled inserts have thermo-hydraulic performance factor in the range of 0.59-1.29, 0.6-1.39, respectively. The empirical correlations of Nusselt number and friction factor for helical coiled inserts are proposed.

Multi-factorial analysis of class prediction error: estimating optimal number of biomarkers for various classification rules.

PubMed

Khondoker, Mizanur R; Bachmann, Till T; Mewissen, Muriel; Dickinson, Paul; Dobrzelecki, Bartosz; Campbell, Colin J; Mount, Andrew R; Walton, Anthony J; Crain, Jason; Schulze, Holger; Giraud, Gerard; Ross, Alan J; Ciani, Ilenia; Ember, Stuart W J; Tlili, Chaker; Terry, Jonathan G; Grant, Eilidh; McDonnell, Nicola; Ghazal, Peter

2010-12-01

Machine learning and statistical model based classifiers have increasingly been used with more complex and high dimensional biological data obtained from high-throughput technologies. Understanding the impact of various factors associated with large and complex microarray datasets on the predictive performance of classifiers is computationally intensive, under investigated, yet vital in determining the optimal number of biomarkers for various classification purposes aimed towards improved detection, diagnosis, and therapeutic monitoring of diseases. We investigate the impact of microarray based data characteristics on the predictive performance for various classification rules using simulation studies. Our investigation using Random Forest, Support Vector Machines, Linear Discriminant Analysis and k-Nearest Neighbour shows that the predictive performance of classifiers is strongly influenced by training set size, biological and technical variability, replication, fold change and correlation between biomarkers. Optimal number of biomarkers for a classification problem should therefore be estimated taking account of the impact of all these factors. A database of average generalization errors is built for various combinations of these factors. The database of generalization errors can be used for estimating the optimal number of biomarkers for given levels of predictive accuracy as a function of these factors. Examples show that curves from actual biological data resemble that of simulated data with corresponding levels of data characteristics. An R package optBiomarker implementing the method is freely available for academic use from the Comprehensive R Archive Network (http://www.cran.r-project.org/web/packages/optBiomarker/).

The extent of interorganizational resource sharing among local health departments: the association with organizational characteristics and institutional factors.

PubMed

Vest, Joshua R; Shah, Gulzar H

2012-11-01

Resource sharing, arrangements between local health departments (LHDs) for joint programs or to share staff, is a growing occurrence. The post-9/11 influx of federal funding and new public health preparedness responsibilities dramatically increased the occurrence of these inter-LHD relationships, and several states have pursed more intrastate collaboration. This article describes the current state of resource sharing among LHDs and identifies the factors associated with resource sharing. Using the National Association of County & City Health Officials' 2010 Profile Survey, we determined the self-reported number of shared programmatic activities and the number of shared organizational functions for a sample of LHDs. Negative binomial regression models described the relationships between factors suggested by interorganizational theory and the counts of sharing activities. We examined the extent of resource sharing using 2 different count variables: (1) number of shared programmatic activities and (2) number of shared organizational functions. About one-half of all LHDs are engaged in resource sharing. The extent of sharing was lower for those serving larger populations, with city jurisdictions, or of larger size. Sharing was more extensive for state-governed LHDs, those covering multiple jurisdictions, states with centralized governance, and in instances of financial constraint. Many LHDs are engaged in a greater extent of resource sharing than others. Leaders of LHDs can work within the context of these factors to leverage resource sharing to meet their organizational needs.

Self-reported teamwork in family health team practices in Ontario: organizational and cultural predictors of team climate.

PubMed

Howard, Michelle; Brazil, Kevin; Akhtar-Danesh, Noori; Agarwal, Gina

2011-05-01

To determine the organizational predictors of higher scores on team climate measures as an indicator of the functioning of a family health team (FHT). Cross-sectional study using a mailed survey. Family health teams in Ontario. Twenty-one of 144 consecutively approached FHTs; 628 team members were surveyed. Scores on the team climate inventory, which assessed organizational culture type (group, developmental, rational, or hierarchical); leadership perceptions; and organizational factors, such as use of electronic medical records (EMRs), team composition, governance of the FHT, location, meetings, and time since FHT initiation. All analyses were adjusted for clustering of respondents within the FHT using a mixed random-intercepts model. The response rate was 65.8% (413 of 628); 2 were excluded from analysis, for a total of 411 participants. At the time of survey completion, there was a median of 4 physicians, 11 other health professionals, and 4 management and clerical staff per FHT. The average team climate score was 3.8 out of a possible 5. In multivariable regression analysis, leadership score, group and developmental culture types, and use of more EMR capabilities were associated with higher team climate scores. Other organizational factors, such as number of sites and size of group, were not associated with the team climate score. Culture, leadership, and EMR functionality, rather than organizational composition of the teams (eg, number of professionals on staff, practice size), were the most important factors in predicting climate in primary care teams.

Family size preference and factors affecting the fertility rate in Hyogo, Japan.

PubMed

Matsumoto, Yasuyo; Yamabe, Shingo

2013-01-30

Japan has consistently shown a low fertility rate, which has been lower than the replacement level since 1974, and represents one of the least fertile countries in the world. This study was designed to determine the family size preference of and its effect on Japanese women. We conducted a questionnaire survey among women who visited the obstetrics and gynecology department of 18 hospitals and clinics in the Hyogo Prefecture, Japan, between October 2011 and February 2012. All the women were categorized according to age group and area of residence, and the survey results were statistically analyzed using a t test. A total of 1616 women were included in this study. There was no significant difference between the mean desired and actual marital ages (26.70 and 26.67 years, respectively). The mean desired number of children was 2.55, which was significantly more than the mean actual number of children (1.77) in all generations. The mean desired and actual numbers of children were more in the rural areas (2.73 and 2.09, respectively) than in the urban (2.54 and 1.70, respectively) and semi-urban areas (2.49 and 1.60, respectively). The mean number of family members was significantly greater in the rural areas (3.84) than in the urban (3.25) and semi-urban areas (3.05).The most important concern among women who had never delivered a baby was childbearing itself, followed by the expenses related to pregnancy and childbearing. The family size preference of the women in our study was higher than the actual numbers of children. The fertility intentions were low among the younger women but high among those living in rural areas with larger families.

Technical note: Alternatives to reduce adipose tissue sampling bias.

PubMed

Cruz, G D; Wang, Y; Fadel, J G

2014-10-01

Understanding the mechanisms by which nutritional and pharmaceutical factors can manipulate adipose tissue growth and development in production animals has direct and indirect effects in the profitability of an enterprise. Adipocyte cellularity (number and size) is a key biological response that is commonly measured in animal science research. The variability and sampling of adipocyte cellularity within a muscle has been addressed in previous studies, but no attempt to critically investigate these issues has been proposed in the literature. The present study evaluated 2 sampling techniques (random and systematic) in an attempt to minimize sampling bias and to determine the minimum number of samples from 1 to 15 needed to represent the overall adipose tissue in the muscle. Both sampling procedures were applied on adipose tissue samples dissected from 30 longissimus muscles from cattle finished either on grass or grain. Briefly, adipose tissue samples were fixed with osmium tetroxide, and size and number of adipocytes were determined by a Coulter Counter. These results were then fit in a finite mixture model to obtain distribution parameters of each sample. To evaluate the benefits of increasing number of samples and the advantage of the new sampling technique, the concept of acceptance ratio was used; simply stated, the higher the acceptance ratio, the better the representation of the overall population. As expected, a great improvement on the estimation of the overall adipocyte cellularity parameters was observed using both sampling techniques when sample size number increased from 1 to 15 samples, considering both techniques' acceptance ratio increased from approximately 3 to 25%. When comparing sampling techniques, the systematic procedure slightly improved parameters estimation. The results suggest that more detailed research using other sampling techniques may provide better estimates for minimum sampling.

Analysis of factors affecting failure of glass cermet tunnel restorations in a multi-center study.

PubMed

Pilebro, C E; van Dijken, J W

2001-06-01

The aim of this study was to analyze factors influencing the failures of tunnel restorations performed with a glass cermet cement (Ketac Silver). Caries activity, lesion size, tunnel cavity opening size, partial or total tunnel, composite lamination or operating time showed no significant correlation to failure rate. Twelve dentists in eight clinics clinically experienced and familiar with the tunnel technique placed 374 restorations. The occlusal sections of fifty percent of the restorations were laminated with hybrid resin composite. The results of the yearly clinical and radiographic evaluations over the course of 3 years were correlated to factors that could influence the failure rate using logistic regression analysis. At the 3-year recall a cumulative number of 305 restorations were available. The cumulative replacement rate was 20%. The main reasons for replacement were marginal ridge fracture (14%) and dentin caries (3%). Another 7% of the restorations which had not been replaced were classified as failures because of untreated dentin caries. The only significant variable observed was the individual failure rate of the participating dentists varying between 9 and 50% (p=0.013).

Influence of light and plant size on the reproduction and growth of small palm tree species: Comparing two methods for measuring canopy openness.

PubMed

Amadeu, Luã S N; Sampaio, Mauricio B; Dos Santos, Flavio A M

2016-09-01

The reproduction and growth of large palms are influenced by many factors, including light and plant size, but few studies have examined smaller species (up to 2 m tall). We examined the effect of incident light and individual size on growth rates, the probability of reproduction, and the number of inflorescences of three small palm species and compared two methods for estimating canopy openness. We measured canopy openness above the crowns of 132 adult plants and in the centers of 72 subplots (10 × 10 m) where individuals were sampled. We also recorded individual size and the number of leaves and inflorescences produced in two years. Reproductive individuals of Butia paraguayensis tend to occur in illuminated microhabitats. Reproduction of Acrocomia emensis was correlated with stem diameter, but not with light. Reproduction was inversely related to individual size and light in Syagrus petraea, probably because this clonal palm invests heavily in sexual reproduction during its younger stages and clonal activity in older stages and may be adapted to the low-light conditions of the woodland understory. Growth was not predicted by light or individual size. Stronger correlations were found when incident light was measured directly above the crown, as opposed to the subplot center. The influences of light on reproduction are dependent on plant life histories, even among related and sympatric species. Light measurements directly above individual crowns provide better understanding of the reproductive effort rather than in subplot center. © 2016 Botanical Society of America.

Genetic factors affecting EBV copy number in lymphoblastoid cell lines derived from the 1000 Genome Project samples.

PubMed

Mandage, Rajendra; Telford, Marco; Rodríguez, Juan Antonio; Farré, Xavier; Layouni, Hafid; Marigorta, Urko M; Cundiff, Caitlin; Heredia-Genestar, Jose Maria; Navarro, Arcadi; Santpere, Gabriel

2017-01-01

Epstein-Barr virus (EBV), human herpes virus 4, has been classically associated with infectious mononucleosis, multiple sclerosis and several types of cancers. Many of these diseases show marked geographical differences in prevalence, which points to underlying genetic and/or environmental factors. Those factors may include a different susceptibility to EBV infection and viral copy number among human populations. Since EBV is commonly used to transform B-cells into lymphoblastoid cell lines (LCLs) we hypothesize that differences in EBV copy number among individual LCLs may reflect differential susceptibility to EBV infection. To test this hypothesis, we retrieved whole-genome sequenced EBV-mapping reads from 1,753 LCL samples derived from 19 populations worldwide that were sequenced within the context of the 1000 Genomes Project. An in silico methodology was developed to estimate the number of EBV copy number in LCLs and validated these estimations by real-time PCR. After experimentally confirming that EBV relative copy number remains stable over cell passages, we performed a genome wide association analysis (GWAS) to try detecting genetic variants of the host that may be associated with EBV copy number. Our GWAS has yielded several genomic regions suggestively associated with the number of EBV genomes per cell in LCLs, unraveling promising candidate genes such as CAND1, a known inhibitor of EBV replication. While this GWAS does not unequivocally establish the degree to which genetic makeup of individuals determine viral levels within their derived LCLs, for which a larger sample size will be needed, it potentially highlighted human genes affecting EBV-related processes, which constitute interesting candidates to follow up in the context of EBV related pathologies.

Expression of Glial Cell Line-Derived Neurotrophic Factor (GDNF) and the GDNF Family Receptor Alpha Subunit 1 in the Paravaginal Ganglia of Nulliparous and Primiparous Rabbits.

PubMed

García-Villamar, Verónica; Hernández-Aragón, Laura G; Chávez-Ríos, Jesús R; Ortega, Arturo; Martínez-Gómez, Margarita; Castelán, Francisco

2018-01-01

To evaluate the expression of glial cell line-derived neurotrophic factor (GDNF) and its receptor, GDNF family receptor alpha subunit 1 (GFRα-1) in the pelvic (middle third) vagina and, particularly, in the paravaginal ganglia of nulliparous and primiparous rabbits. Chinchilla-breed female rabbits were used. Primiparas were killed on postpartum day 3 and nulliparas upon reaching a similar age. The vaginal tracts were processed for histological analyses or frozen for Western blot assays. We measured the ganglionic area, the Abercrombie-corrected number of paravaginal neurons, the cross-sectional area of the neuronal somata, and the number of satellite glial cells (SGCs) per neuron. The relative expression of both GDNF and GFRα-1 were assessed by Western blotting, and the immunostaining was semiquantitated. Unpaired two-tailed Student t -test or Wilcoxon test was used to identify statistically significant differences (P≤0.05) between the groups. Our findings demonstrated that the ganglionic area, neuronal soma size, Abercrombie-corrected number of neurons, and number of SGCs per neuron were similar in nulliparas and primiparas. The relative expression of both GDNF and GFRα-1 was similar. Immunostaining for both GDNF and GFRα-1 was observed in several vaginal layers, and no differences were detected regarding GDNF and GFRα-1 immunostaining between the 2 groups. In the paravaginal ganglia, the expression of GDNF was increased in neurons, while that of GFRα-1 was augmented in the SGCs of primiparous rabbits. The present findings suggest an ongoing regenerative process related to the recovery of neuronal soma size in the paravaginal ganglia, in which GDNF and GFRα-1 could be involved in cross-talk between neurons and SGCs.

Correlation of quantitative histopathological morphology and quantitative radiological analysis during aseptic loosening of hip endoprostheses.

PubMed

Bertz, S; Kriegsmann, J; Eckardt, A; Delank, K-S; Drees, P; Hansen, T; Otto, M

2006-01-01

Aseptic hip prosthesis loosening is the most important long-term complication in total hip arthroplasty. Polyethylene (PE) wear is the dominant etiologic factor in aseptic loosening, which together with other factors induces mechanisms resulting in bone loss, and finally in implant loosening. The single-shot radiograph analysis (EBRA, abbreviation for the German term "Einzel-Bild-Röntgenanalyse") is a computerized method for early radiological prediction of aseptic loosening. In this study, EBRA parameters were correlated with histomorphological parameters of the periprosthetic membrane. Periprosthetic membranes obtained from 19 patients during revision surgery of loosened ABG I-type total hip pros-theses were analyzed histologically and morphometrically. The pre-existing EBRA parameters, the thickness of the PE debris lay-er and the dimension of inclination and anteversion, were compared with the density of macrophages and giant cells. Addi-tionally, the semiquantitatively determined density of lymphocytes, plasma cells, giant cells and the size of the necrotic areas were correlated with the EBRA results. All periprosthetic membranes were classified as debris-induced type membranes. We found a positive correlation between the number of giant cells and the thickness of the PE debris layer. There was no significant correlation between the number of macrophages or all semiquantitative parameters and EBRA parameters. The number of giant cells decreased with implant duration. The morphometrically measured number of foreign body giant cells more closely reflects the results of the EBRA. The semiquantitative estimation of giant cell density could not substitute for the morphometrical analysis. The density of macrophages, lymphocytes, plasma cells and the size of necrotic areas did not correlate with the EBRA parameters, indicating that there is no correlation with aseptic loosening.

Coronary artery calcium: a multi-institutional, multimanufacturer international standard for quantification at cardiac CT.

PubMed

McCollough, Cynthia H; Ulzheimer, Stefan; Halliburton, Sandra S; Shanneik, Kaiss; White, Richard D; Kalender, Willi A

2007-05-01

To develop a consensus standard for quantification of coronary artery calcium (CAC). A standard for CAC quantification was developed by a multi-institutional, multimanufacturer international consortium of cardiac radiologists, medical physicists, and industry representatives. This report specifically describes the standardization of scan acquisition and reconstruction parameters, the use of patient size-specific tube current values to achieve a prescribed image noise, and the use of the calcium mass score to eliminate scanner- and patient size-based variations. An anthropomorphic phantom containing calibration inserts and additional phantom rings were used to simulate small, medium-size, and large patients. The three phantoms were scanned by using the recommended protocols for various computed tomography (CT) systems to determine the calibration factors that relate measured CT numbers to calcium hydroxyapatite density and to determine the tube current values that yield comparable noise values. Calculation of the calcium mass score was standardized, and the variance in Agatston, volume, and mass scores was compared among CT systems. Use of the recommended scanning parameters resulted in similar noise for small, medium-size, and large phantoms with all multi-detector row CT scanners. Volume scores had greater interscanner variance than did Agatston and calcium mass scores. Use of a fixed calcium hydroxyapatite density threshold (100 mg/cm(3)), as compared with use of a fixed CT number threshold (130 HU), reduced interscanner variability in Agatston and calcium mass scores. With use of a density segmentation threshold, the calcium mass score had the smallest variance as a function of patient size. Standardized quantification of CAC yielded comparable image noise, spatial resolution, and mass scores among different patient sizes and different CT systems and facilitated reduced radiation dose for small and medium-size patients.

The influence of life history trade-offs and the size of the incubation gravels on egg size variation in sockeye salmon Onchorhynchus nerka

USGS Publications Warehouse

Quinn, Thomas P.; Hendry , Andrew P.; Wetzel, Lisa A.

1995-01-01

Egg size is a critical life history trait, reflecting female investment and affecting off- spring fitness. We investigated several factors which may influence variation in egg weight for sockeye salmon (Oncorhynchus nerka). Comparisons were based on col- lections from 18 Alaskan populations, among which adult migration distance and ju- venile rearing habitat were similar but the size composition of incubation gravels was different. Among populations, most of the variation in egg weight could be explained by a positive correlation with different measures of the size composition of incubation gravels (Pearson's r = 0.45-0.91). In contrast, egg weight was poorly correlated with female body length and with female snout length, a morphological feature used during intra-sexual competition. Within each of the Alaskan populations, however, egg weight and snout length were positively correlated with female body length and hence with each other. A positive association between snout length and egg weight was still evident even after the effects of covariance with body size were removed using resid- uals analysis: for all of the fish pooled and within 6 of the 16 populations. A signifi- cant relationship was not detected in the other populations but the trend was neverthe- less positive in 8 of the other 10. Examination of reproductive traits (gonad weight, egg weight, egg number, snout length and hump size) within another population iden- tified a trade-off between egg weight and egg number for females of a given body length. In contrast, positive correlations between reproductive traits were more com- mon, suggesting that energy-rich individuals produce large eggs and large secondary sexual characteristics rather than sacrificing one for the other.

2006 : Wood Products Used in New Residential Construction U.S. and Canada, with Comparisons to 1995, 1998 and 2003 : Executive Summary

Treesearch

Craig Adair; David B. McKeever

2009-01-01

The construction of new single family, multifamily, and manufactured housing is an important market for wood products in both the United States and Canada. Annual wood products consumption is dependent on many factors, including the number of new units started, the size of units started, architectural characteristics, and consumer preferences. In 2006, about 39 percent...

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

Padaki, S.; Drzal, L.T.

The consolidation process in composites made out of powder impregnated tapes differs from that of other material forms because of the distribution of fiber and matrix in the unconsolidated state. A number of factors (e.g. time, pressure, particle size, volume fraction and viscosity) affect the efficiency of the consolidation of these tapes. This paper describes the development of a mathematical process model that describes the best set of parameters required for the consolidation of a given prepreg tape.

Air quality impact and physicochemical aging of biomass burning aerosols during the 2007 San Diego wildfires.

PubMed

Zauscher, Melanie D; Wang, Ying; Moore, Meagan J K; Gaston, Cassandra J; Prather, Kimberly A

2013-07-16

Intense wildfires burning >360000 acres in San Diego during October, 2007 provided a unique opportunity to study the impact of wildfires on local air quality and biomass burning aerosol (BBA) aging. The size-resolved mixing state of individual particles was measured in real-time with an aerosol time-of-flight mass spectrometer (ATOFMS) for 10 days after the fires commenced. Particle concentrations were high county-wide due to the wildfires; 84% of 120-400 nm particles by number were identified as BBA, with particles <400 nm contributing to mass concentrations dangerous to public health, up to 148 μg/m(3). Evidence of potassium salts heterogeneously reacting with inorganic acids was observed with continuous high temporal resolution for the first time. Ten distinct chemical types shown as BBA factors were identified through positive matrix factorization coupled to single particle analysis, including particles comprised of potassium chloride and organic nitrogen during the beginning of the wildfires, ammonium nitrate and amines after an increase of relative humidity, and sulfate dominated when the air mass back trajectories passed through the Los Angeles port region. Understanding BBA aging processes and quantifying the size-resolved mass and number concentrations are important in determining the overall impact of wildfires on air quality, health, and climate.

Control of a Normal Shock Boundary Layer Interaction with Ramped Vanes of Various Sizes

NASA Astrophysics Data System (ADS)

Lee, Sang; Loth, Eric

2017-11-01

A novel vortex generator design positioned upstream of a normal shock and a subsequent diffuser was investigated using large eddy simulations. In particular, ``ramped-vane'' flow control devices with three difference heights relative to the incoming boundary layer thickness (0.34 δ 0.52 δ and 0.75 δ were placed in a supersonic boundary layer with a freestream Mach number of 1.3 and a Reynolds number of 2,400 based on momentum thickness. These devices are similar to subsonic vanes but are designed to be more mechanically robust while having low wave drag. The devices generated strong streamwise vortices that entrained high momentum fluid to the near-wall region and increased turbulent mixing. The devices also decreased shock-induced flow separation, which resulted in a higher downstream skin friction in the diffuser. In general, the largest ramped-vane (0.75 δ) produced the largest reductions in flow separation, shape factor and overall unsteadiness. However, the medium-sized ramped vane (0.52 δ) was able to also reduce both the separation area and the diffuser displacement thickness. The smallest device (0.34 δ) had a weak impact of the flow in the diffuser, though a 10% reduction in the shape factor was achieved.

Recovery of Weak Factor Loadings When Adding the Mean Structure in Confirmatory Factor Analysis: A Simulation Study

PubMed Central

Ximénez, Carmen

2016-01-01

This article extends previous research on the recovery of weak factor loadings in confirmatory factor analysis (CFA) by exploring the effects of adding the mean structure. This issue has not been examined in previous research. This study is based on the framework of Yung and Bentler (1999) and aims to examine the conditions that affect the recovery of weak factor loadings when the model includes the mean structure, compared to analyzing the covariance structure alone. A simulation study was conducted in which several constraints were defined for one-, two-, and three-factor models. Results show that adding the mean structure improves the recovery of weak factor loadings and reduces the asymptotic variances for the factor loadings, particularly for the models with a smaller number of factors and a small sample size. Therefore, under certain circumstances, modeling the means should be seriously considered for covariance models containing weak factor loadings. PMID:26779071

Histories of Puerto Rican parrot nests in the Caribbean National Forest/Luquillo Experimental Forest, 1973-2000

USGS Publications Warehouse

Wunderle, J.M.; Snyder, N.F.R.; Muiznieks, B.; Wiley, J.W.; Meyers, J.M.

2003-01-01

This publication summarizes the histories of all known Puerto Rican parrot nests in the Caribbean National Forest/Luquillo Experimental Forest from 1973 through 2000. Included for each nest, when known, are the identifies of the pair, clutch size, known fertile and infertile eggs, number of eggs that hatched, number of chicks that survived, sources of mortality, fostering (source, destination. or both), number of young fledged from the pair and from the nest, and percentage of days the nest was guarded. This information is useful for detecting and assessing potential changes in reproductive output and nest threats and is fundamental for understanding some of the demographic and genetic factors influencing the wild parrot population.

Theoretical study of electron transport along self-assembled graphitic nanowires

NASA Astrophysics Data System (ADS)

Paulsson, Magnus; Stafström, Sven

2000-11-01

Electron transport through stacks of polyaromatic hydrocarbons is studied theoretically using the Landauer formalism. The polyaromatic hydrocarbons can be synthesized in many different sizes and can form molecular stacks with a varying number of molecules and with a rather strong π-overlap along the stack. This allows for a large flexibility in the nanostructure of these materials and makes it possible to study the variation in the conductance with a number of different factors: a near-linear increase in the conductance as a function of the number of atoms in the individual molecule is observed. Furthermore, the conductance drops exponentially with the number of molecules in the stacks, from which it follows that an increase in the intermolecular hopping results in an increase in the conductance which is proportional to the intermolecular hopping to the power of 2(N-1), where N is the number of molecules in the stack.

A "hydrokinematic" method of measuring the glide efficiency of a human swimmer.

PubMed

Naemi, Roozbeh; Sanders, Ross H

2008-12-01

The aim of this study was to develop and test a method of quantifying the glide efficiency, defined as the ability of the body to maintain its velocity over time and to minimize deceleration through a rectilinear glide. The glide efficiency should be determined in a way that accounts for both the inertial and resistive characteristics of the gliding body as well as the instantaneous velocity. A displacement function (parametric curve) was obtained from the equation of motion of the body during a horizontal rectilinear glide. The values of the parameters in the displacement curve that provide the best fit to the displacement-time data of a body during a rectilinear horizontal glide represent the glide factor and the initial velocity of the particular glide interval. The glide factor is a measure of glide efficiency and indicates the ability of the body to minimize deceleration at each corresponding velocity. The glide efficiency depends on the hydrodynamic characteristic of the body, which is influenced by the body's shape as well as by the body's size. To distinguish the effects of size and shape on the glide efficiency, a size-related glide constant and a shape-related glide coefficient were determined as separate entities. The glide factor is the product of these two parameters. The goodness of fit statistics indicated that the representative displacement function found for each glide interval closely represents the real displacement data of a body in a rectilinear horizontal glide. The accuracy of the method was indicated by a relative standard error of calculation of less than 2.5%. Also the method was able to distinguish between subjects in their glide efficiency. It was found that the glide factor increased with decreasing velocity. The glide coefficient also increased with decreasing Reynolds number. The method is sufficiently accurate to distinguish between individual swimmers in terms of their glide efficiency. The separation of glide factor to a size-related glide constant and a shape-related glide coefficient enabled the effect of size and shape to be quantified.

The application of a linear algebra to the analysis of mutation rates.

PubMed

Jones, M E; Thomas, S M; Clarke, K

1999-07-07

Cells and bacteria growing in culture are subject to mutation, and as this mutation is the ultimate substrate for selection and evolution, the factors controlling the mutation rate are of some interest. The mutational event is not observed directly, but is inferred from the phenotype of the original mutant or of its descendants; the rate of mutation is inferred from the number of such mutant phenotypes. Such inference presumes a knowledge of the probability distribution for the size of a clone arising from a single mutation. We develop a mathematical formulation that assists in the design and analysis of experiments which investigate mutation rates and mutant clone size distribution, and we use it to analyse data for which the classical Luria-Delbrück clone-size distribution must be rejected. Copyright 1999 Academic Press.

Marketing environment dynamics and implications for pricing strategies: the case of home health care.

PubMed

Ponsford, B J; Barlow, D

1999-01-01

This research reviews the factors affecting the pricing or rate schedules of home health care agencies. A large number of factors affect costs and thus rate structures. The major factors include reimbursement structures with accompanying discount structures, administrative burdens, and risks. Channel issues include bargaining power, competition, and size. Staffing issues affect pricing and product through the provider level, productivity, and quality outcomes. Physician and patient issues include quality concerns and choices. These factors are discussed in light of overall marketing strategy and the interaction of pricing with other marketing controllables such as product, place/distribution, and promotion. Economic and accounting principles are also reviewed with consideration to understanding direct and indirect costs in order to enable negotiators to effectively price health care services.

Small field detector correction factors: effects of the flattening filter for Elekta and Varian linear accelerators

PubMed Central

Liu, Paul Z.Y.; Lee, Christopher; McKenzie, David R.; Suchowerska, Natalka

2016-01-01

Flattening filter‐free (FFF) beams are becoming the preferred beam type for stereotactic radiosurgery (SRS) and stereotactic ablative radiation therapy (SABR), as they enable an increase in dose rate and a decrease in treatment time. This work assesses the effects of the flattening filter on small field output factors for 6 MV beams generated by both Elekta and Varian linear accelerators, and determines differences between detector response in flattened (FF) and FFF beams. Relative output factors were measured with a range of detectors (diodes, ionization chambers, radiochromic film, and microDiamond) and referenced to the relative output factors measured with an air core fiber optic dosimeter (FOD), a scintillation dosimeter developed at Chris O'Brien Lifehouse, Sydney. Small field correction factors were generated for both FF and FFF beams. Diode measured detector response was compared with a recently published mathematical relation to predict diode response corrections in small fields. The effect of flattening filter removal on detector response was quantified using a ratio of relative detector responses in FFF and FF fields for the same field size. The removal of the flattening filter was found to have a small but measurable effect on ionization chamber response with maximum deviations of less than ±0.9% across all field sizes measured. Solid‐state detectors showed an increased dependence on the flattening filter of up to ±1.6%. Measured diode response was within ±1.1% of the published mathematical relation for all fields up to 30 mm, independent of linac type and presence or absence of a flattening filter. For 6 MV beams, detector correction factors between FFF and FF beams are interchangeable for a linac between FF and FFF modes, providing that an additional uncertainty of up to ±1.6% is accepted. PACS number(s): 87.55.km, 87.56.bd, 87.56.Da PMID:27167280

Are Physical Activity and Nutrition Indicators of the Checklist of Health Promotion Environments at Worksites (CHEW) Associated with Employee Obesity among Hotel Workers?

PubMed Central

Nigg, Claudio R.; Albright, Cheryl; Williams, Rebecca; Nichols, Carol; Renda, Gloria; Stevens, Victor J.; Vogt, Thomas M.

2010-01-01

Objective Worksites provide opportunities to reach more than 60% of adults in the United States, including populations diverse in race, ethnicity, gender, age, occupation, income, and health status. Employers that provide worksite weight management interventions have the potential to reduce sick leave, healthcare costs, and workers compensation costs, and increase employee morale and worker efficiency. Hotels specifically, represent a broad cross-section of job categories, and most hotels are staffed and operated similarly around the world. However, from our literature review, there have been no investigations of the association between the hotel environment and employees’ obesity. Methods For this study, we tested the relationship between environmental factors in hotels and employees’ body mass index (BMI). Results Overall no substantial correlations were found on any environmental variable. However, hotel size affected some relationships. Higher BMI was related to greater number of stairs, stair facilitation, and the healthy eating facilitation variables (excluding nutrition signs or posters) in medium sized hotels. Lower BMI was found with greater stair facilitation in small hotels; and with greater number of PA signs, lunchroom nutrition signs, and hotel nutrition signsin large hotels. Unionized status affected only two environmental variables. For unionized hotels, BMI was negatively correlated with PA signs and positively correlated with the healthy eating facilitation. Conclusions No logical pattern of association was found between workplace environmental factors and hotel employee BMI levels. Further research should investigate the interaction of the size and structure of the workplace with the impact of environmental efforts to reduce overweight and obesity. PMID:20061886

Prediction of Hematopoietic Stem Cell Transplantation Related Mortality- Lessons Learned from the In-Silico Approach: A European Society for Blood and Marrow Transplantation Acute Leukemia Working Party Data Mining Study.

PubMed

Shouval, Roni; Labopin, Myriam; Unger, Ron; Giebel, Sebastian; Ciceri, Fabio; Schmid, Christoph; Esteve, Jordi; Baron, Frederic; Gorin, Norbert Claude; Savani, Bipin; Shimoni, Avichai; Mohty, Mohamad; Nagler, Arnon

2016-01-01

Models for prediction of allogeneic hematopoietic stem transplantation (HSCT) related mortality partially account for transplant risk. Improving predictive accuracy requires understating of prediction limiting factors, such as the statistical methodology used, number and quality of features collected, or simply the population size. Using an in-silico approach (i.e., iterative computerized simulations), based on machine learning (ML) algorithms, we set out to analyze these factors. A cohort of 25,923 adult acute leukemia patients from the European Society for Blood and Marrow Transplantation (EBMT) registry was analyzed. Predictive objective was non-relapse mortality (NRM) 100 days following HSCT. Thousands of prediction models were developed under varying conditions: increasing sample size, specific subpopulations and an increasing number of variables, which were selected and ranked by separate feature selection algorithms. Depending on the algorithm, predictive performance plateaued on a population size of 6,611-8,814 patients, reaching a maximal area under the receiver operator characteristic curve (AUC) of 0.67. AUCs' of models developed on specific subpopulation ranged from 0.59 to 0.67 for patients in second complete remission and receiving reduced intensity conditioning, respectively. Only 3-5 variables were necessary to achieve near maximal AUCs. The top 3 ranking variables, shared by all algorithms were disease stage, donor type, and conditioning regimen. Our findings empirically demonstrate that with regards to NRM prediction, few variables "carry the weight" and that traditional HSCT data has been "worn out". "Breaking through" the predictive boundaries will likely require additional types of inputs.

Impact of Childbearing Decisions on Family Size of Korean Women with Systemic Lupus Erythematosus

PubMed Central

2016-01-01

Systemic lupus erythematosus (SLE) predominantly affects women in their reproductive years and has a significant impact on childbearing. We investigated the influence of personal decision on family size among Korean women with SLE and factors that affect the decisions. A case-control study comparing childbearing history and decisions of 112 SLE patients and 135 controls was performed. Women with SLE participating in the Network for Lupus Clinical Research in South Korea and matching controls between ages of 18-45, who are/were married or living with a partner were included. Data regarding socio-demographics, reproductive history, and childbearing decisions were collected through a survey using a standardized questionnaire and medical record review. More women with SLE reported at least one pregnancy (85.7% vs. 71.9%, P = 0.009) or at least one live birth (85.7% vs. 71.9%, P = 0.003) compared with controls. Mean number of pregnancies was significantly higher (2.4 ± 1.6 vs. 1.4 ± 1.3, P < 0.001), and mean number of live births was significantly lower in women with SLE (1.2 ± 0.8 vs. 1.6 ± 0.8, P < 0.001). Significantly more women with SLE made the decision not to have children compared with controls (54.5% vs. 40.7%, P = 0.031), and health-related concerns were the major cause of the decision. Other socio-demographic factors did not influence the decision to limit childbearing in SLE women. The disease-related concerns had significant impact on family size and childbearing decisions among Korean women with SLE. PMID:27134494

Impact of Childbearing Decisions on Family Size of Korean Women with Systemic Lupus Erythematosus.

PubMed

Kim, In Je; Kim, Hyoun-Ah; Suh, Chang-Hee; Park, Yong-Wook; Lee, Hye-Soon; Bang, So-Young; Bae, Sang-Cheol; Kang, Young Mo; Lee, Won Kyung; Park, Hyesook; Lee, Jisoo

2016-05-01

Systemic lupus erythematosus (SLE) predominantly affects women in their reproductive years and has a significant impact on childbearing. We investigated the influence of personal decision on family size among Korean women with SLE and factors that affect the decisions. A case-control study comparing childbearing history and decisions of 112 SLE patients and 135 controls was performed. Women with SLE participating in the Network for Lupus Clinical Research in South Korea and matching controls between ages of 18-45, who are/were married or living with a partner were included. Data regarding socio-demographics, reproductive history, and childbearing decisions were collected through a survey using a standardized questionnaire and medical record review. More women with SLE reported at least one pregnancy (85.7% vs. 71.9%, P = 0.009) or at least one live birth (85.7% vs. 71.9%, P = 0.003) compared with controls. Mean number of pregnancies was significantly higher (2.4 ± 1.6 vs. 1.4 ± 1.3, P < 0.001), and mean number of live births was significantly lower in women with SLE (1.2 ± 0.8 vs. 1.6 ± 0.8, P < 0.001). Significantly more women with SLE made the decision not to have children compared with controls (54.5% vs. 40.7%, P = 0.031), and health-related concerns were the major cause of the decision. Other socio-demographic factors did not influence the decision to limit childbearing in SLE women. The disease-related concerns had significant impact on family size and childbearing decisions among Korean women with SLE.

Bibliometric assessment of publication output of child and adolescent psychiatric/psychological affiliations between 2005 and 2010 based on the databases PubMed and Scopus.

PubMed

Albayrak, Ozgür; Föcker, Manuel; Wibker, Katrin; Hebebrand, Johannes

2012-06-01

We aimed to determine the quantitative scientific publication output of child and adolescent psychiatric/psychological affiliations during 2005-2010 by country based on both, "PubMed" and "Scopus" and performed a bibliometric qualitative evaluation for 2009 using "PubMed". We performed our search by affiliation related to child and adolescent psychiatric/psychological institutions using "PubMed". For the quantitative analysis for 2005-2010, we counted the number of abstracts. For the qualitative analysis for 2009 we derived the impact factor of each abstract's journal from "Journal Citation Reports". We related total impact factor scores to the gross domestic product (GDP) and population size of each country. Additionally, we used "Scopus" to determine the number of abstracts for each country that was identified via "PubMed" for 2009 and compared the ranking of countries between the two databases. 61 % of the publications between 2005 and 2010 originated from European countries and 26 % from the USA. After adjustment for GDP and population size, the ranking positions changed in favor of smaller European countries with a population size of less than 20 million inhabitants. The ranking of countries for the count of articles in 2009 as derived from "Scopus" was similar to that identified via the "PubMed" search. The performed search revealed only minor differences between "Scopus" and "PubMed" related to the ranking of countries. Our data indicate a sharp difference between countries with a high versus low GDP with regard to scientific publication output in child and adolescent psychiatry/psychology.

Are physical activity and nutrition indicators of the checklist of health promotion environments at worksites (CHEW) associated with employee obesity among hotel workers?

PubMed

Nigg, Claudio R; Albright, Cheryl; Williams, Rebecca; Nichols, Carol; Renda, Gloria; Stevens, Victor J; Vogt, Thomas M

2010-01-01

Worksites provide opportunities to reach more than 60% of adults in the United States, including populations diverse in race, ethnicity, gender, age, occupation, income, and health status. Employers that provide worksite weight management interventions have the potential to reduce sick leave, health care costs, and workers compensation costs, and increase employee morale and worker efficiency. Hotels specifically, represent a broad cross-section of job categories, and most hotels are staffed and operated similarly around the world. However, from our literature review, there have been no investigations of the association between the hotel environment and employees' obesity. For this study, we tested the relationship between environmental factors in hotels and employees' body mass index (BMI). Overall no substantial correlations were found on any environmental variable. However, hotel size affected some relationships. Higher BMI was related to greater number of stairs, stair facilitation, and the healthy eating facilitation variables (excluding nutrition signs or posters) in medium sized hotels. Lower BMI was found with greater stair facilitation in small hotels; and with greater number of physical activity (PA) signs, lunch room nutrition signs, and hotel nutrition signs in large hotels. Unionized status affected only two environmental variables. For unionized hotels, BMI was negatively correlated with PA signs and positively correlated with the healthy eating facilitation. No logical pattern of association was found between workplace environmental factors and hotel employee BMI levels. Further research should investigate the interaction of the size and structure of the workplace with the impact of environmental efforts to reduce overweight and obesity.

A two-phase model of resource allocation in visual working memory.

PubMed

Ye, Chaoxiong; Hu, Zhonghua; Li, Hong; Ristaniemi, Tapani; Liu, Qiang; Liu, Taosheng

2017-10-01

Two broad theories of visual working memory (VWM) storage have emerged from current research, a discrete slot-based theory and a continuous resource theory. However, neither the discrete slot-based theory or continuous resource theory clearly stipulates how the mental commodity for VWM (discrete slot or continuous resource) is allocated. Allocation may be based on the number of items via stimulus-driven factors, or it may be based on task demands via voluntary control. Previous studies have obtained conflicting results regarding the automaticity versus controllability of such allocation. In the current study, we propose a two-phase allocation model, in which the mental commodity could be allocated only by stimulus-driven factors in the early consolidation phase. However, when there is sufficient time to complete the early phase, allocation can enter the late consolidation phase, where it can be flexibly and voluntarily controlled according to task demands. In an orientation recall task, we instructed participants to store either fewer items at high-precision or more items at low-precision. In 3 experiments, we systematically manipulated memory set size and exposure duration. We did not find an effect of task demands when the set size was high and exposure duration was short. However, when we either decreased the set size or increased the exposure duration, we found a trade-off between the number and precision of VWM representations. These results can be explained by a two-phase model, which can also account for previous conflicting findings in the literature. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Cross-species correlation between queen mating numbers and worker ovary sizes suggests kin conflict may influence ovary size evolution in honeybees

NASA Astrophysics Data System (ADS)

Rueppell, Olav; Phaincharoen, Mananya; Kuster, Ryan; Tingek, Salim

2011-09-01

During social evolution, the ovary size of reproductively specialized honey bee queens has dramatically increased while their workers have evolved much smaller ovaries. However, worker division of labor and reproductive competition under queenless conditions are influenced by worker ovary size. Little comparative information on ovary size exists in the different honey bee species. Here, we report ovariole numbers of freshly dissected workers from six Apis species from two locations in Southeast Asia. The average number of worker ovarioles differs significantly among species. It is strongly correlated with the average mating number of queens, irrespective of body size. Apis dorsata, in particular, is characterized by numerous matings and very large worker ovaries. The relation between queen mating number and ovary size across the six species suggests that individual selection via reproductive competition plays a role in worker ovary size evolution. This indicates that genetic diversity, generated by multiple mating, may bear a fitness cost at the colony level.

Population estimate of the preantral follicles and frequency of multioocyte follicles in prepubertal and adult bitches.

PubMed

Lunardon, N T; Silva-Santos, K C; Justino, R C; Dessunti, G T; Seneda, M M; Martins, M I M

2015-04-01

Oocytes from preantral follicles could be an alternative for in vitro maturation because most follicles are at the preantral stage. There are few studies that have sought to estimate the number of preantral follicles in bitches. Therefore, the aims of this study were to estimate the population of preantral follicles in the ovaries of small- and medium-sized prepubertal and adult bitches and compare the population of preantral follicles between the right and left ovaries and evaluate the frequency of multioocyte follicles (MOF). Eighty ovaries were collected by elective ovariohysterectomy from 40 healthy bitches. The bitches were divided into four groups: small-size prepubertal bitches (<10 kg, n = 20), medium-size prepubertal bitches (10-20 kg, n = 20), small-size adult bitches (<10 kg, n = 20), and medium-size adult bitches (10-20 kg, n = 20). Immediately after surgery, the ovaries were fixed in Bouin's solution and processed for histology. For each specimen, 70 histologic sections were cut and mounted on slides; then, the number of preantral follicles was estimated using a correction factor. The preantral follicles were classified according to the developmental stage. The data were analyzed using the Kruskal-Wallis test followed by Dunn's test for comparison between groups, and Fisher's exact test was used to evaluate the frequency of MOF (P ≤ 0.05). Considering the population of preantral follicles from the pair of ovaries, medium-size prepubertal bitches had the highest (P < 0.05) population of preantral follicles compared with the small and medium-size adult groups. There was a large variation in the numbers of preantral follicles among individuals of the same weight and within each group. There were differences between medium-size prepubertal and adult bitches regarding the population of preantral follicles in the right ovaries (145,482 ± 110,712 vs. 49,500 ± 44,821; P = 0.02); however, no differences were observed between the groups on the basis of comparisons of the number of preantral follicles in the left ovaries (P > 0.05). The prevalence of primordial MOF was higher in prepubertal bitches (47% vs. 28%), whereas adult bitches had a higher frequency of secondary MOF (49% vs. 25%; P < 0.05). We conclude that medium-size prepubertal bitches had the highest population of preantral follicles compared with small and medium-size adult bitches, and the use of only one ovary per bitch implied contrasting result. The presence of primordial MOF was higher in prepubertal bitches and at the secondary stage in adult bitches. Copyright © 2015 Elsevier Inc. All rights reserved.

Uranium resource assessment by the Geological Survey; methodology and plan to update the national resource base

USGS Publications Warehouse

Finch, Warren Irvin; McCammon, Richard B.

1987-01-01

Based on the Memorandum of Understanding {MOU) of September 20, 1984, between the U.S. Geological Survey of the U.S. Department of Interior and the Energy Information Administration {EIA) of the U.S. Department of Energy {DOE), the U.S. Geological Survey began to make estimates of the undiscovered uranium endowment of selected areas of the United States in 1985. A modified NURE {National Uranium Resource Evaluation) method will be used in place of the standard NURE method of the DOE that was used for the national assessment reported in October 1980. The modified method, here named the 'deposit-size-frequency' {DSF) method, is presented for the first time, and calculations by the two methods are compared using an illustrative example based on preliminary estimates for the first area to be evaluated under the MOU. The results demonstrate that the estimate of the endowment using the DSF method is significantly larger and more uncertain than the estimate obtained by the NURE method. We believe that the DSF method produces a more realistic estimate because the principal factor estimated in the endowment equation is disaggregated into more parts and is more closely tied to specific geologic knowledge than by the NURE method. The DSF method consists of modifying the standard NURE estimation equation, U=AxFxTxG, by replacing the factors FxT by a single factor that represents the tonnage for the total number of deposits in all size classes. Use of the DSF method requires that the size frequency of deposits in a known or control area has been established and that the relation of the size-frequency distribution of deposits to probable controlling geologic factors has been determined. Using these relations, the principal scientist {PS) first estimates the number and range of size classes and then, for each size class, estimates the lower limit, most likely value, and upper limit of the numbers of deposits in the favorable area. Once these probable estimates have been refined by elicitation of the PS, they are entered into the DSF equation, and the probability distribution of estimates of undiscovered uranium endowment is calculated using a slight modification of the program by Ford and McLaren (1980). The EIA study of the viability of the domestic uranium industry requires an annual appraisal of the U.S. uranium resource situation. During DOE's NURE Program, which was terminated in 1983, a thorough assessment of the Nation's resources was completed. A comprehensive reevaluation of uranium resource base for the entire United States is not possible for each annual appraisal. A few areas are in need of future study, however, because of new developments in either scientific knowledge, industry exploration, or both. Four geologic environments have been selected for study by the U.S. Geological Survey in the next several years: (1) surficial uranium deposits throughout the conterminous United States, (2) uranium in collapse-breccia pipes in the Grand Canyon region of Arizona, (3) uranium in Tertiary sedimentary rocks of the Northern Great Plains, and (4) uranium in metamorphic rocks of the Piedmont province in the eastern States. In addition to participation in the National uranium resource assessment, the U.S. Geological Survey will take part in activities of the Nuclear Energy Agency of the Organization for Economic Cooperation and Development and those of the International Atomic Energy Agency.

Meta-analysis and systematic review of the number of non-syndromic congenitally missing permanent teeth per affected individual and its influencing factors

PubMed Central

Rakhshan, Hamid

2016-01-01

Summary Background and purpose: Dental aplasia (or hypodontia) is a frequent and challenging anomaly and thus of interest to many dental fields. Although the number of missing teeth (NMT) in each person is a major clinical determinant of treatment need, there is no meta-analysis on this subject. Therefore, we aimed to investigate the relevant literature, including epidemiological studies and research on dental/orthodontic patients. Methods: Among 50 reports, the effects of ethnicities, regions, sample sizes/types, subjects’ minimum ages, journals’ scientific credit, publication year, and gender composition of samples on the number of missing permanent teeth (except the third molars) per person were statistically analysed (α = 0.05, 0.025, 0.01). Limitations: The inclusion of small studies and second-hand information might reduce the reliability. Nevertheless, these strategies increased the meta-sample size and favoured the generalisability. Moreover, data weighting was carried out to account for the effect of study sizes/precisions. Results: The NMT per affected person was 1.675 [95% confidence interval (CI) = 1.621–1.728], 1.987 (95% CI = 1.949–2.024), and 1.893 (95% CI = 1.864–1.923), in randomly selected subjects, dental/orthodontic patients, and both groups combined, respectively. The effects of ethnicities (P > 0.9), continents (P > 0.3), and time (adjusting for the population type, P = 0.7) were not significant. Dental/orthodontic patients exhibited a significantly greater NMT compared to randomly selected subjects (P < 0.012). Larger samples (P = 0.000) and enrolling younger individuals (P = 0.000) might inflate the observed NMT per person. Conclusions: Time, ethnic backgrounds, and continents seem unlikely influencing factors. Subjects younger than 13 years should be excluded. Larger samples should be investigated by more observers. PMID:25840586

Pollen foraging in colonies of Melipona bicolor (Apidae, Meliponini): effects of season, colony size and queen number.

PubMed

Hilário, S D; Imperatriz-Fonseca, V L

2009-01-01

We evaluated the ratio between the number of pollen foragers and the total number of bees entering colonies of Melipona bicolor, a facultative polygynous species of stingless bees. The variables considered in our analysis were: seasonality, colony size and the number of physogastric queens in each colony. The pollen forager ratios varied significantly between seasons; the ratio was higher in winter than in summer. However, colony size and number of queens per colony had no significant effect. We conclude that seasonal differences in pollen harvest are related to the production of sexuals and to the number of individuals and their body size.

Cell Number Regulator1 Affects Plant and Organ Size in Maize: Implications for Crop Yield Enhancement and Heterosis[C][W

PubMed Central

Guo, Mei; Rupe, Mary A.; Dieter, Jo Ann; Zou, Jijun; Spielbauer, Daniel; Duncan, Keith E.; Howard, Richard J.; Hou, Zhenglin; Simmons, Carl R.

2010-01-01

Genes involved in cell number regulation may affect plant growth and organ size and, ultimately, crop yield. The tomato (genus Solanum) fruit weight gene fw2.2, for instance, governs a quantitative trait locus that accounts for 30% of fruit size variation, with increased fruit size chiefly due to increased carpel ovary cell number. To expand investigation of how related genes may impact other crop plant or organ sizes, we identified the maize (Zea mays) gene family of putative fw2.2 orthologs, naming them Cell Number Regulator (CNR) genes. This family represents an ancient eukaryotic family of Cys-rich proteins containing the PLAC8 or DUF614 conserved motif. We focused on native expression and transgene analysis of the two maize members closest to Le-fw2.2, namely, CNR1 and CNR2. We show that CNR1 reduced overall plant size when ectopically overexpressed and that plant and organ size increased when its expression was cosuppressed or silenced. Leaf epidermal cell counts showed that the increased or decreased transgenic plant and organ size was due to changes in cell number, not cell size. CNR2 expression was found to be negatively correlated with tissue growth activity and hybrid seedling vigor. The effects of CNR1 on plant size and cell number are reminiscent of heterosis, which also increases plant size primarily through increased cell number. Regardless of whether CNRs and other cell number–influencing genes directly contribute to, or merely mimic, heterosis, they may aid generation of more vigorous and productive crop plants. PMID:20400678

Changes in seasonal climate outpace compensatory density-dependence in eastern brook trout

USGS Publications Warehouse

Bassar, Ronald D.; Letcher, Benjamin H.; Nislow, Keith H.; Whiteley, Andrew R.

2016-01-01

Understanding how multiple extrinsic (density-independent) factors and intrinsic (density-dependent) mechanisms influence population dynamics has become increasingly urgent in the face of rapidly changing climates. It is particularly unclear how multiple extrinsic factors with contrasting effects among seasons are related to declines in population numbers and changes in mean body size and whether there is a strong role for density-dependence. The primary goal of this study was to identify the roles of seasonal variation in climate driven environmental direct effects (mean stream flow and temperature) versus density-dependence on population size and mean body size in eastern brook trout (Salvelinus fontinalis). We use data from a 10-year capture-mark-recapture study of eastern brook trout in four streams in Western Massachusetts, USA to parameterize a discrete-time population projection model. The model integrates matrix modeling techniques used to characterize discrete population structures (age, habitat type and season) with integral projection models (IPMs) that characterize demographic rates as continuous functions of organismal traits (in this case body size). Using both stochastic and deterministic analyses we show that decreases in population size are due to changes in stream flow and temperature and that these changes are larger than what can be compensated for through density-dependent responses. We also show that the declines are due mostly to increasing mean stream temperatures decreasing the survival of the youngest age class. In contrast, increases in mean body size over the same period are the result of indirect changes in density with a lesser direct role of climate-driven environmental change.

Effect of surfactants on the deformation of single droplet in shear flow studied by dissipative particle dynamics

NASA Astrophysics Data System (ADS)

Zhang, Yuzhou; Xu, Junbo; He, Xianfeng

2018-07-01

The behaviour of a single droplet in shear flow is a fundamental problem in immiscible liquid-liquid multiphase fluid systems. In this article, the deformation and inclination angle of single droplet covered with surfactants in shear flow at moderate Reynolds number, when both the inertial effects and interfacial tension are the key governing factors, were simulated by dissipative particle dynamics (DPD). Weber number We was adopted to indicate the force state of the droplet and a linear relationship between the deformation parameter D and We was found when Reynolds number Re is about 1-10, which is similar to the relation of D and Capillary number Ca when Re ≪ 1. When the surfactant concentration is lower than the critical micelle concentration (CMC), the distribution of surfactants, the droplet inclination angle θ and the droplet deformation parameter D were investigated at different surfactant density at interface ds and shear rate ?. When the droplet size is close to the characteristic size of surfactant molecules, phase interfaces of water in oil (W/O) and oil in water (O/W) systems have different microstructures, which result in differences in the surfactant distribution, the droplet inclination angle and deformation of the two systems.

Deposition of biomass combustion aerosol particles in the human respiratory tract.

PubMed

Löndahl, Jakob; Pagels, Joakim; Boman, Christoffer; Swietlicki, Erik; Massling, Andreas; Rissler, Jenny; Blomberg, Anders; Bohgard, Mats; Sandström, Thomas

2008-08-01

Smoke from biomass combustion has been identified as a major environmental risk factor associated with adverse health effects globally. Deposition of the smoke particles in the lungs is a crucial factor for toxicological effects, but has not previously been studied experimentally. We investigated the size-dependent respiratory-tract deposition of aerosol particles from wood combustion in humans. Two combustion conditions were studied in a wood pellet burner: efficient ("complete") combustion and low-temperature (incomplete) combustion simulating "wood smoke." The size-dependent deposition fraction of 15-to 680-nm particles was measured for 10 healthy subjects with a novel setup. Both aerosols were extensively characterized with regard to chemical and physical particle properties. The deposition was additionally estimated with the ICRP model, modified for the determined aerosol properties, in order to validate the experiments and allow a generalization of the results. The measured total deposited fraction of particles from both efficient combustion and low-temperature combustion was 0.21-0.24 by number, surface, and mass. The deposition behavior can be explained by the size distributions of the particles and by their ability to grow by water uptake in the lungs, where the relative humidity is close to saturation. The experiments were in basic agreement with the model calculations. Our findings illustrate: (1) that particles from biomass combustion obtain a size in the respiratory tract at which the deposition probability is close to its minimum, (2) that particle water absorption has substantial impact on deposition, and (3) that deposition is markedly influenced by individual factors.

Communications between intraretinal and subretinal space on optical coherence tomography of neurosensory retinal detachment in diabetic macular edema

PubMed Central

Gupta, Aditi; Raman, Rajiv; Mohana, KP; Kulothungan, Vaitheeswaran; Sharma, Tarun

2013-01-01

Background: The pathogenesis of development and progression of neurosensory retinal detachment (NSD) in diabetic macular edema (DME) is not yet fully understood. The purpose of this study is to describe the spectral domain optical coherence tomography (SD-OCT) morphological characteristics of NSD associated with DME in the form of outer retinal communications and to assess the correlation between the size of communications and various factors. Materials and Methods: This was an observational retrospective nonconsecutive case series in a tertiary care eye institute. We imaged NSD and outer retinal communications in 17 eyes of 16 patients having NSD associated with DME using SD-OCT. We measured manually the size of the outer openings of these communications and studied its correlation with various factors. Statistical analysis (correlation test) was performed using the Statistical Package for Social Sciences (SPSS) software (version 14.0). The main outcome measures were correlation of the size of communications with dimensions of NSD, presence of subretinal hyper-reflective dots, and best-corrected visual acuity (BCVA). Results: The communications were seen as focal defects of the outer layers of elevated retina. With increasing size of communication, there was increase in height of NSD (r = 0.701, P = 0.002), horizontal diameter of NSD (r = 0.695, P = 0.002), and the number of hyper-reflective dots in the subretinal space (r = 0.729, P = 0.002). The minimum angle of resolution (logMAR) BCVA increased with the increasing size of communications (r = 0.827, P < 0.0001). Conclusions: Outer retinal communications between intra and subretinal space were noted in eyes having NSD associated with DME. The size of communications correlated positively with the size of NSD and subretinal detachment space hyper-reflective dots, and inversely with BCVA. PMID:24379554

Communications between intraretinal and subretinal space on optical coherence tomography of neurosensory retinal detachment in diabetic macular edema.

PubMed

Gupta, Aditi; Raman, Rajiv; Mohana, Kp; Kulothungan, Vaitheeswaran; Sharma, Tarun

2013-09-01

The pathogenesis of development and progression of neurosensory retinal detachment (NSD) in diabetic macular edema (DME) is not yet fully understood. The purpose of this study is to describe the spectral domain optical coherence tomography (SD-OCT) morphological characteristics of NSD associated with DME in the form of outer retinal communications and to assess the correlation between the size of communications and various factors. This was an observational retrospective nonconsecutive case series in a tertiary care eye institute. We imaged NSD and outer retinal communications in 17 eyes of 16 patients having NSD associated with DME using SD-OCT. We measured manually the size of the outer openings of these communications and studied its correlation with various factors. Statistical analysis (correlation test) was performed using the Statistical Package for Social Sciences (SPSS) software (version 14.0). The main outcome measures were correlation of the size of communications with dimensions of NSD, presence of subretinal hyper-reflective dots, and best-corrected visual acuity (BCVA). The communications were seen as focal defects of the outer layers of elevated retina. With increasing size of communication, there was increase in height of NSD (r = 0.701, P = 0.002), horizontal diameter of NSD (r = 0.695, P = 0.002), and the number of hyper-reflective dots in the subretinal space (r = 0.729, P = 0.002). The minimum angle of resolution (logMAR) BCVA increased with the increasing size of communications (r = 0.827, P < 0.0001). Outer retinal communications between intra and subretinal space were noted in eyes having NSD associated with DME. The size of communications correlated positively with the size of NSD and subretinal detachment space hyper-reflective dots, and inversely with BCVA.

Effects of calorie labeling and value size pricing on fast food meal choices: Results from an experimental trial

PubMed Central

Harnack, Lisa J; French, Simone A; Oakes, J Michael; Story, Mary T; Jeffery, Robert W; Rydell, Sarah A

2008-01-01

Background Although point-of-purchase calorie labeling at restaurants has been proposed as a strategy for improving consumer food choices, a limited number of studies have evaluated this approach. Likewise, little research has been conducted to evaluate the influence of value size pricing on restaurant meal choices. Methods To examine the effect of point-of-purchase calorie information and value size pricing on fast food meal choices a randomized 2 × 2 factorial experiment was conducted in which participants ordered a fast food meal from one of four menus that varied with respect to whether calorie information was provided and whether value size pricing was used. Study participants included 594 adolescents and adults who regularly ate at fast food restaurants. Study staff recorded the foods ordered and consumed by each participant. Participants also completed surveys to assess attitudes, beliefs and practices related to fast food and nutrition. Results No significant differences in the energy composition of meals ordered or eaten were found between menu conditions. The average energy content of meals ordered by those randomized to a menu that included calorie information and did not include value size pricing was 842 kcals compared with 827 kcals for those who ordered their meal from a menu that did not include calorie information but had value size pricing (control menu). Results were similar in most analyses conducted stratified by factors such as age, race and education level. Conclusion Additional research is needed to better evaluate the effects of calorie labeling and value size pricing on fast food meal choices. Studies in which participants are repeatedly exposed to these factors are needed since long term exposure may be required for behavior change. PMID:19061510

Effects of calorie labeling and value size pricing on fast food meal choices: results from an experimental trial.

PubMed

Harnack, Lisa J; French, Simone A; Oakes, J Michael; Story, Mary T; Jeffery, Robert W; Rydell, Sarah A

2008-12-05

Although point-of-purchase calorie labeling at restaurants has been proposed as a strategy for improving consumer food choices, a limited number of studies have evaluated this approach. Likewise, little research has been conducted to evaluate the influence of value size pricing on restaurant meal choices. To examine the effect of point-of-purchase calorie information and value size pricing on fast food meal choices a randomized 2 x 2 factorial experiment was conducted in which participants ordered a fast food meal from one of four menus that varied with respect to whether calorie information was provided and whether value size pricing was used. Study participants included 594 adolescents and adults who regularly ate at fast food restaurants. Study staff recorded the foods ordered and consumed by each participant. Participants also completed surveys to assess attitudes, beliefs and practices related to fast food and nutrition. No significant differences in the energy composition of meals ordered or eaten were found between menu conditions. The average energy content of meals ordered by those randomized to a menu that included calorie information and did not include value size pricing was 842 kcals compared with 827 kcals for those who ordered their meal from a menu that did not include calorie information but had value size pricing (control menu). Results were similar in most analyses conducted stratified by factors such as age, race and education level. Additional research is needed to better evaluate the effects of calorie labeling and value size pricing on fast food meal choices. Studies in which participants are repeatedly exposed to these factors are needed since long term exposure may be required for behavior change.

Heterogeneity of Mosquito (Diptera: Culicidae) Control Community Size, Research Productivity, and Arboviral Diseases Across the United States.

PubMed

Hamer, Gabriel L

2016-05-01

Multiple factors lead to extensive variation in mosquito and mosquito-borne virus control programs throughout the United States. This variation is related to differences in budgets, number of personnel, operational activities targeting nuisance or vector species, integration of Geographical Information Systems, and the degree of research and development to improve management interventions through collaboration with academic institutions. To highlight this heterogeneity, the current study evaluates associations among the size of a mosquito control community, the research productivity, and the mosquito-borne virus human disease burden among states within the continental United States. I used the attendance at state mosquito and vector control meetings as a proxy for the size of the mosquito control community in each state. To judge research productivity, I used all peer-reviewed publications on mosquitoes and mosquito-borne viruses using data originating in each state over a 5- and 20-yr period. Total neuroinvasive human disease cases caused by mosquito-borne viruses were aggregated for each state. These data were compared directly and after adjusting for differences in human population size for each state. Results revealed that mean meeting attendance was positively correlated with the number of publications in each state, but not after correcting for the size of the population in each state. Additionally, human disease cases were positively correlated with the number of publications in each state. Finally, mean meeting attendance and human disease cases were only marginally positively associated, and no correlation existed after correcting for human population size. These analyses indicated that the mosquito control community size, research productivity, and mosquito-borne viral human disease burden varied greatly among states. The mechanisms resulting in this variation were discussed and the consequences of this variation are important given the constantly changing environment due to invasive mosquito species and arboviruses, urbanization, immigration, global travel, and climate change. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Characteristics of dilute gas-solids suspensions in drag reducing flow

NASA Technical Reports Server (NTRS)

Kane, R. S.; Pfeffer, R.

1973-01-01

Measurements were performed on dilute flowing gas-solids suspensions and included data, with particles present, on gas friction factors, velocity profiles, turbulence intensity profiles, turbulent spectra, and particle velocity profiles. Glass beads of 10 to 60 micron diameter were suspended in air at Reynolds numbers of 10,000 to 25,000 and solids loading ratios from 0 to 4. Drag reduction was achieved for all particle sizes in vertical flow and for the smaller particle sizes in horizontal flow. The profile measurements in the vertical tube indicated that the presence of particles thickened the viscous sublayer. A quantitative theory based on particle-eddy interaction and viscous sublayer thickening has been proposed.

Small size of metastatic lymph nodes with extracapsular spread greatly impacts treatment outcomes in oral squamous cell carcinoma patients.

PubMed

Michikawa, C; Izumo, T; Sumino, J; Morita, T; Ohyama, Y; Michi, Y; Uzawa, N

2018-07-01

Extracapsular spread (ECS) of metastatic lymph nodes from oral carcinoma is the most significant prognostic predictor of a poor treatment outcome. However, only a few reports on prognostic factors in ECS-positive cases have been investigated. To address this problem, a detailed examination of ECS pathology was conducted to determine the prognostic factors of oral squamous cell carcinoma (OSCC) with ECS of metastatic lymph nodes. This study involved 63 OSCC patients with at least one pathologically metastatic node with ECS. Among the 229 metastatic lymph nodes, 149 exhibited ECS. Univariate analysis revealed that a poor outcome and recurrence were significantly associated with the number of ECS-positive nodes, density of ECS, and the minor axis of the smallest ECS-positive node. However, multivariate analysis identified only small size of ECS-positive nodes as a significant and independent factor predicting recurrence and a poor outcome. Thus, small size of ECS-positive nodes is the most important prognostic indicator for OSCC with ECS in metastatic lymph nodes. The classification of ECS status using the minor axis of ECS-positive nodes may be useful for further prediction of a poorer prognosis in OSCC cases. Standardization of ECS diagnosis and multicenter prospective studies will be required to confirm and refine these findings. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Relative efficiency and sample size for cluster randomized trials with variable cluster sizes.

PubMed

You, Zhiying; Williams, O Dale; Aban, Inmaculada; Kabagambe, Edmond Kato; Tiwari, Hemant K; Cutter, Gary

2011-02-01

The statistical power of cluster randomized trials depends on two sample size components, the number of clusters per group and the numbers of individuals within clusters (cluster size). Variable cluster sizes are common and this variation alone may have significant impact on study power. Previous approaches have taken this into account by either adjusting total sample size using a designated design effect or adjusting the number of clusters according to an assessment of the relative efficiency of unequal versus equal cluster sizes. This article defines a relative efficiency of unequal versus equal cluster sizes using noncentrality parameters, investigates properties of this measure, and proposes an approach for adjusting the required sample size accordingly. We focus on comparing two groups with normally distributed outcomes using t-test, and use the noncentrality parameter to define the relative efficiency of unequal versus equal cluster sizes and show that statistical power depends only on this parameter for a given number of clusters. We calculate the sample size required for an unequal cluster sizes trial to have the same power as one with equal cluster sizes. Relative efficiency based on the noncentrality parameter is straightforward to calculate and easy to interpret. It connects the required mean cluster size directly to the required sample size with equal cluster sizes. Consequently, our approach first determines the sample size requirements with equal cluster sizes for a pre-specified study power and then calculates the required mean cluster size while keeping the number of clusters unchanged. Our approach allows adjustment in mean cluster size alone or simultaneous adjustment in mean cluster size and number of clusters, and is a flexible alternative to and a useful complement to existing methods. Comparison indicated that we have defined a relative efficiency that is greater than the relative efficiency in the literature under some conditions. Our measure of relative efficiency might be less than the measure in the literature under some conditions, underestimating the relative efficiency. The relative efficiency of unequal versus equal cluster sizes defined using the noncentrality parameter suggests a sample size approach that is a flexible alternative and a useful complement to existing methods.

Synthesis and characterization of silver-nanoparticle-impregnated fiberglass and utility in water disinfection.

PubMed

Nangmenyi, Gordon; Yue, Zhongren; Mehrabi, Sharifeh; Mintz, Eric; Economy, James

2009-12-09

A number of researchers have deployed silver (Ag) nanoparticles through a number of techniques on various substrates including carbon, zeolites and polymers for water disinfection applications. However, Ag impregnated on an inorganic fiberglass surface through a simple electroless process was only recently reported for the first time. Fiberglass impregnated with Ag nanoparticles displays superior performance over carbon-based silver support systems but little is known about the factors that affect the architecture of the system, its interfacial properties and its consequent bactericidal activity. In this study, Ag content and particle size on a fiberglass substrate were manipulated by adjusting the AgNO(3) concentration, immersion time, temperature, solution pH and reduction temperature. The reduction chemistry of the Ag-nanoparticle-impregnated fiberglass is described and supported with thermal gravimetric analysis (TGA) and photoelectron spectroscopy (XPS) measurements. The Ag content along with the particle size and particle size distribution were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS) and x-ray diffraction (XRD). The Ag content on the fiberglass mats ranged from 0.04 to 4.7 wt% Ag/g-fiber with a size distribution of 10-900 nm under standard processing conditions. Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze the Ag desorption from the fiberglass substrate, while the bactericidal properties were evaluated against Escherichia coli (E. coli).

Synthesis and characterization of silver-nanoparticle-impregnated fiberglass and utility in water disinfection

NASA Astrophysics Data System (ADS)

Nangmenyi, Gordon; Yue, Zhongren; Mehrabi, Sharifeh; Mintz, Eric; Economy, James

2009-12-01

A number of researchers have deployed silver (Ag) nanoparticles through a number of techniques on various substrates including carbon, zeolites and polymers for water disinfection applications. However, Ag impregnated on an inorganic fiberglass surface through a simple electroless process was only recently reported for the first time. Fiberglass impregnated with Ag nanoparticles displays superior performance over carbon-based silver support systems but little is known about the factors that affect the architecture of the system, its interfacial properties and its consequent bactericidal activity. In this study, Ag content and particle size on a fiberglass substrate were manipulated by adjusting the AgNO3 concentration, immersion time, temperature, solution pH and reduction temperature. The reduction chemistry of the Ag-nanoparticle-impregnated fiberglass is described and supported with thermal gravimetric analysis (TGA) and photoelectron spectroscopy (XPS) measurements. The Ag content along with the particle size and particle size distribution were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS) and x-ray diffraction (XRD). The Ag content on the fiberglass mats ranged from 0.04 to 4.7 wt% Ag/g-fiber with a size distribution of 10-900 nm under standard processing conditions. Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze the Ag desorption from the fiberglass substrate, while the bactericidal properties were evaluated against Escherichia coli (E. coli).

Monitoring the impact of Bt maize on butterflies in the field: estimation of required sample sizes.

PubMed

Lang, Andreas

2004-01-01

The monitoring of genetically modified organisms (GMOs) after deliberate release is important in order to assess and evaluate possible environmental effects. Concerns have been raised that the transgenic crop, Bt maize, may affect butterflies occurring in field margins. Therefore, a monitoring of butterflies was suggested accompanying the commercial cultivation of Bt maize. In this study, baseline data on the butterfly species and their abundance in maize field margins is presented together with implications for butterfly monitoring. The study was conducted in Bavaria, South Germany, between 2000-2002. A total of 33 butterfly species was recorded in field margins. A small number of species dominated the community, and butterflies observed were mostly common species. Observation duration was the most important factor influencing the monitoring results. Field margin size affected the butterfly abundance, and habitat diversity had a tendency to influence species richness. Sample size and statistical power analyses indicated that a sample size in the range of 75 to 150 field margins for treatment (transgenic maize) and control (conventional maize) would detect (power of 80%) effects larger than 15% in species richness and the butterfly abundance pooled across species. However, a much higher number of field margins must be sampled in order to achieve a higher statistical power, to detect smaller effects, and to monitor single butterfly species.

Source appointment of fine particle number and volume concentration during severe haze pollution in Beijing in January 2013.

PubMed

Liu, Zirui; Wang, Yuesi; Hu, Bo; Ji, Dongsheng; Zhang, Junke; Wu, Fangkun; Wan, Xin; Wang, Yonghong

2016-04-01

Extreme haze episodes repeatedly shrouded Beijing during the winter of 2012-2013, causing major environmental and health problems. To better understand these extreme events, particle number size distribution (PNSD) and particle chemical composition (PCC) data collected in an intensive winter campaign in an urban site of Beijing were used to investigate the sources of ambient fine particles. Positive matrix factorization (PMF) analysis resolved a total of eight factors: two traffic factors, combustion factors, secondary aerosol, two accumulation mode aerosol factors, road dust, and long-range transported (LRT) dust. Traffic emissions (54%) and combustion aerosol (27%) were found to be the most important sources for particle number concentration, whereas combustion aerosol (33%) and accumulation mode aerosol (37%) dominated particle volume concentrations. Chemical compositions and sources of fine particles changed dynamically in the haze episodes. An enhanced role of secondary inorganic species was observed in the formation of haze pollution. Regional transport played an important role for high particles, contribution of which was on average up to 24-49% during the haze episodes. Secondary aerosols from urban background presented the largest contributions (45%) for the rapid increase of fine particles in the severest haze episode. In addition, the invasion of LRT dust aerosols further elevated the fine particles during the extreme haze episode. Our results showed a clear impact of regional transport on the local air pollution, suggesting the importance of regional-scale emission control measures in the local air quality management of Beijing.

Differential roles of fibrinogen and von Willebrand factor on clot formation and platelet adhesion in reconstituted and immune thrombocytopenia.

PubMed

Misgav, Mudi; Shenkman, Boris; Budnik, Ivan; Einav, Yulia; Martinowitz, Uri

2011-05-01

Bleeding tendencies in immune thrombocytopenia (ITP) do not always correlate with the number of platelets, suggesting platelet function variation. We used a model of normal whole blood thrombocytopenia to compare platelet function and other hemostatic variables with ITP patients. We further investigated the effect of in vitro spiking with von Willebrand factor (vWF) and fibrinogen on platelet function and hemostatic variables. The Cone and Plate(let) Analyzer was used to measure platelet adhesion (surface coverage [SC], %) and aggregation (average size, μm(2)) under defined shear rate (1200 s(-1)). Rotational thromboelastometry was used to determine variables of clot formation triggered by CaCl(2) and tissue factor. In both the model of thrombocytopenia as well as in ITP, the SC and to some extent the average size were correlated to the platelet number over a range of 5 to 80 × 10(6)/mL. The results obtained for most ITP samples were within the boundaries of the lower and upper limits set by the whole blood model of thrombocytopenia. The addition of 2 U/mL vWF (Haemate-P) to whole blood (calculated to plasma volume) results in an increase in the SC and average size without affecting clot formation. Spiking with fibrinogen (100 and 300 mg/dL) did not affect platelet deposition but improved clot formation. Using a model of whole blood thrombocytopenia enables us to establish reference variables for the Cone and Plate(let) Analyzer and rotational thromboelastometry and to assess platelet function and clot formation in the presence of severe thrombocytopenia. We demonstrated that in most cases of ITP, platelet function is comparable to normal platelets. This work also suggests that vWF and fibrinogen differentially affect primary and secondary hemostasis and therefore both may perform a function in the bleeding phenotype and possibly may be considered for treatment in patients with ITP. © 2011 International Anesthesia Research Society

Optimum 3D Matrix Stiffness for Maintenance of Cancer Stem Cells Is Dependent on Tissue Origin of Cancer Cells

PubMed Central

Jabbari, Esmaiel; Sarvestani, Samaneh K.; Daneshian, Leily; Moeinzadeh, Seyedsina

2015-01-01

Introduction The growth and expression of cancer stem cells (CSCs) depend on many factors in the tumor microenvironment. The objective of this work was to investigate the effect of cancer cells’ tissue origin on the optimum matrix stiffness for CSC growth and marker expression in a model polyethylene glycol diacrylate (PEGDA) hydrogel without the interference of other factors in the microenvironment. Methods Human MCF7 and MDA-MB-231 breast carcinoma, HCT116 colorectal and AGS gastric carcinoma, and U2OS osteosarcoma cells were used. The cells were encapsulated in PEGDA gels with compressive moduli in the 2-70 kPa range and optimized cell seeding density of 0.6x106 cells/mL. Micropatterning was used to optimize the growth of encapsulated cells with respect to average tumorsphere size. The CSC sub-population of the encapsulated cells was characterized by cell number, tumorsphere size and number density, and mRNA expression of CSC markers. Results The optimum matrix stiffness for growth and marker expression of CSC sub-population of cancer cells was 5 kPa for breast MCF7 and MDA231, 25 kPa for colorectal HCT116 and gastric AGS, and 50 kPa for bone U2OS cells. Conjugation of a CD44 binding peptide to the gel stopped tumorsphere formation by cancer cells from different tissue origin. The expression of YAP/TAZ transcription factors by the encapsulated cancer cells was highest at the optimum stiffness indicating a link between the Hippo transducers and CSC growth. The optimum average tumorsphere size for CSC growth and marker expression was 50 μm. Conclusion The marker expression results suggest that the CSC sub-population of cancer cells resides within a niche with optimum stiffness which depends on the cancer cells’ tissue origin. PMID:26168187

Analysis of five-year trends in self-reported language preference and issues of item non-response among Hispanic persons in a large cross-sectional health survey: implications for the measurement of an ethnic minority population

PubMed Central

2010-01-01

Background Significant differences in health outcomes have been documented among Hispanic persons, the fastest-growing demographic segment of the United States. The objective of this study was to examine trends in population growth and the collection of health data among Hispanic persons, including issues of language preference and survey completion using a national health survey to highlight issues of measurement of an increasingly important demographic segment of the United States. Design Data from the 2003-2007 United States Census and the Behavioral Risk Factor Surveillance System were used to compare trends in population growth and survey sample size as well as differences in survey response based on language preference among a Hispanic population. Percentages of item non-response on selected survey questions were compared for Hispanic respondents choosing to complete the survey in Spanish and those choosing to complete the survey in English. The mean number of attempts to complete the survey was also compared based on language preference among Hispanic respondents. Results The sample size of Hispanic persons in the Behavioral Risk Factor Surveillance System saw little growth compared to the actual growth of the Hispanic population in the United States. Significant differences in survey item non-response for nine of 15 survey questions were seen based on language preference. Hispanic respondents choosing to complete the survey in Spanish had a significantly fewer number of call attempts for survey completion compared to their Hispanic counterparts choosing to communicate in English. Conclusions Including additional measures of acculturation and increasing the sample size of Hispanic persons in a national health survey such as the Behavioral Risk Factor Surveillance System may result in more precise findings that could be used to better target prevention and health care needs for an ethnic minority population. PMID:20412575

Resting site use of giant pandas in Wanglang Nature Reserve.

PubMed

Kang, Dongwei; Wang, Xiaorong; Li, Junqing

2017-10-23

Little is known about the resting sites used by the giant panda (Ailuropoda melanoleuca), which restricts our understanding of their resting habits and limits conservation efforts. To enhance our understanding of resting site requirements and factors affecting the resting time of giant pandas, we investigated the characteristics of resting sites in the Wanglang Nature Reserve, Sichuan Province, China. The results indicated that the resting sites of giant pandas were characterised by a mean slope of 21°, mean nearest tree size of 53.75 cm, mean nearest shrub size of 2.82 cm, and mean nearest bamboo number of 56. We found that the resting sites were closer to bamboo than to trees and shrubs, suggesting that the resting site use of giant pandas is closely related to the presence of bamboo. Considering that giant pandas typically rest near a large-sized tree, protection of large trees in the forests is of considerable importance for the conservation of this species. Furthermore, slope was found to be an important factor affecting the resting time of giant pandas, as they tended to rest for a relatively longer time in sites with a smaller degree of slope.

First-principles study of the binding energy between nanostructures and its scaling with system size

NASA Astrophysics Data System (ADS)

Tao, Jianmin; Jiao, Yang; Mo, Yuxiang; Yang, Zeng-Hui; Zhu, Jian-Xin; Hyldgaard, Per; Perdew, John P.

2018-04-01

The equilibrium van der Waals binding energy is an important factor in the design of materials and devices. However, it presents great computational challenges for materials built up from nanostructures. Here we investigate the binding-energy scaling behavior from first-principles calculations. We show that the equilibrium binding energy per atom between identical nanostructures can scale up or down with nanostructure size, but can be parametrized for large N with an analytical formula (in meV/atom), Eb/N =a +b /N +c /N2+d /N3 , where N is the number of atoms in a nanostructure and a , b , c , and d are fitting parameters, depending on the properties of a nanostructure. The formula is consistent with a finite large-size limit of binding energy per atom. We find that there are two competing factors in the determination of the binding energy: Nonadditivities of van der Waals coefficients and center-to-center distance between nanostructures. To decode the detail, the nonadditivity of the static multipole polarizability is investigated from an accurate spherical-shell model. We find that the higher-order multipole polarizability displays ultrastrong intrinsic nonadditivity, no matter if the dipole polarizability is additive or not.

Propulsion Technology Demonstrator. [Demonstrating Novel CubeSat Technologies in Low Earth Orbit

NASA Technical Reports Server (NTRS)

Marmie, John; Martinez, Andres; Petro, Andrew

2015-01-01

NASA's Pathfinder Technology Demonstrator (PTD) project will test the operation of a variety of novel CubeSat technologies in low- Earth orbit, providing significant enhancements to the performance of these small and effective spacecraft. Each Pathfinder Technology Demonstrator mission consists of a 6-unit (6U) CubeSat weighing approximately 26 pounds (12 kilograms) and measuring 12 inches x 10 inches x 4 inches (30 centimeters x 25 centimeters x 10 centimeters), comparable in size to a common shoebox. CubeSats are a class of nanosatellites that use a standard size and form factor. The standard Cube- Sat size uses a "one unit" or "1U" measuring 4 inches x 4 inches x 4 inches (10x10x10 centimeters) and is extendable to larger sizes by "stacking" a number of the 1U blocks to form a larger spacecraft. Each PTD spacecraft will also be equipped with deployable solar arrays that provide an average of 44 watts of power while in orbit.

Neutron and weak-charge distributions of the 48Ca nucleus

DOE PAGES

Hagen, Gaute; Forssen, Christian; Nazarewicz, Witold; ...

2015-11-02

What is the size of the atomic nucleus? This deceivably simple question is difficult to answer. Although the electric charge distributions in atomic nuclei were measured accurately already half a century ago, our knowledge of the distribution of neutrons is still deficient. In addition to constraining the size of atomic nuclei, the neutron distribution also impacts the number of nuclei that can exist and the size of neutron stars. We present an ab initio calculation of the neutron distribution of the neutron-rich nucleus 48Ca. We show that the neutron skin (difference between the radii of the neutron and proton distributions)more » is significantly smaller than previously thought. We also make predictions for the electric dipole polarizability and the weak form factor; both quantities that are at present targeted by precision measurements. Here, based on ab initio results for 48Ca, we provide a constraint on the size of a neutron star.« less

Relationship between size and surface modification of silica particles and enhancement and suppression of inflammatory cytokine production by lipopolysaccharide- or peptidoglycan-stimulated RAW264.7 macrophages

NASA Astrophysics Data System (ADS)

Uemura, Eiichiro; Yoshioka, Yasuo; Hirai, Toshiro; Handa, Takayuki; Nagano, Kazuya; Higashisaka, Kazuma; Tsutsumi, Yasuo

2016-06-01

Although nanomaterials are used in an increasing number of commodities, the relationships between their immunotoxicity and physicochemical properties such as size or surface characteristics are not fully understood. Here we demonstrated that pretreatment with amorphous silica particles (SPs) of various sizes (diameters of 10-1000 nm), with or without amine surface modification, significantly decreased interleukin 6 production by RAW264.7 macrophages following lipopolysaccharide or peptidoglycan stimulation. Furthermore, nanosized, but not microsized, SPs significantly enhanced tumor necrosis factor-α production in macrophages stimulated with lipopolysaccharide. This altered cytokine response was distinct from the inflammatory responses induced by treatment with the SPs alone. Additionally, the uptake of SPs into macrophages by phagocytosis was found to be crucial for the suppression of macrophage immune response to occur, irrespective of particle size or surface modification. Together, these results suggest that SPs may not only increase susceptibility to microbial infection, but that they may also be potentially effective immunosuppressants.

Evolution of floral display in Eichhornia paniculata (Pontederiaceae): direct and correlated responses to selection on flower size and number.

PubMed

Worley, A C; Barrett, S C

2000-10-01

Trade-offs between flower size and number seem likely to influence the evolution of floral display and are an important assumption of several theoretical models. We assessed floral trade-offs by imposing two generations of selection on flower size and number in a greenhouse population of bee-pollinated Eichhornia paniculata. We established a control line and two replicate selection lines of 100 plants each for large flowers (S+), small flowers (S-), and many flowers per inflorescence (N+). We compared realized heritabilities and genetic correlations with estimates based on restricted-maximum-likelihood (REML) analysis of pedigrees. Responses to selection confirmed REML heritability estimates (flower size, h2 = 0.48; daily flower number, h2 = 0.10; total flower number, h2 = 0.23). Differences in nectar, pollen, and ovule production between S+ and S- lines supported an overall divergence in investment per flower. Both realized and REML estimates of the genetic correlation between daily and total flower number were r = 1.0. However, correlated responses to selection were inconsistent in their support of a trade-off. In both S- lines, correlated increases in flower number indicated a genetic correlation of r = -0.6 between flower size and number. In contrast, correlated responses in N+ and S+ lines were not significant, although flower size decreased in one N+ line. In addition, REML estimates of genetic correlations between flower size and number were positive, and did not differ from zero when variation in leaf area and age at first flowering were taken into account. These results likely reflect the combined effects of variation in genes controlling the resources available for flowering and genes with opposing effects on flower size and number. Our results suggest that the short-term evolution of floral display is not necessarily constrained by trade-offs between flower size and number, as is often assumed.

Finite-Size Effects of Binary Mutual Diffusion Coefficients from Molecular Dynamics

PubMed Central

2018-01-01

Molecular dynamics simulations were performed for the prediction of the finite-size effects of Maxwell-Stefan diffusion coefficients of molecular mixtures and a wide variety of binary Lennard–Jones systems. A strong dependency of computed diffusivities on the system size was observed. Computed diffusivities were found to increase with the number of molecules. We propose a correction for the extrapolation of Maxwell–Stefan diffusion coefficients to the thermodynamic limit, based on the study by Yeh and Hummer (J. Phys. Chem. B, 2004, 108, 15873−15879). The proposed correction is a function of the viscosity of the system, the size of the simulation box, and the thermodynamic factor, which is a measure for the nonideality of the mixture. Verification is carried out for more than 200 distinct binary Lennard–Jones systems, as well as 9 binary systems of methanol, water, ethanol, acetone, methylamine, and carbon tetrachloride. Significant deviations between finite-size Maxwell–Stefan diffusivities and the corresponding diffusivities at the thermodynamic limit were found for mixtures close to demixing. In these cases, the finite-size correction can be even larger than the simulated (finite-size) Maxwell–Stefan diffusivity. Our results show that considering these finite-size effects is crucial and that the suggested correction allows for reliable computations. PMID:29664633

Slip Correction Measurements of Certified PSL Nanoparticles Using a Nanometer Differential Mobility Analyzer (Nano-DMA) for Knudsen Number From 0.5 to 83

PubMed Central

Kim, Jung Hyeun; Mulholland, George W.; Kukuck, Scott R.; Pui, David Y. H.

2005-01-01

The slip correction factor has been investigated at reduced pressures and high Knudsen number using polystyrene latex (PSL) particles. Nano-differential mobility analyzers (NDMA) were used in determining the slip correction factor by measuring the electrical mobility of 100.7 nm, 269 nm, and 19.90 nm particles as a function of pressure. The aerosol was generated via electrospray to avoid multiplets for the 19.90 nm particles and to reduce the contaminant residue on the particle surface. System pressure was varied down to 8.27 kPa, enabling slip correction measurements for Knudsen numbers as large as 83. A condensation particle counter was modified for low pressure application. The slip correction factor obtained for the three particle sizes is fitted well by the equation: C = 1 + Kn (α + β exp(−γ/Kn)), with α = 1.165, β = 0.483, and γ = 0.997. The first quantitative uncertainty analysis for slip correction measurements was carried out. The expanded relative uncertainty (95 % confidence interval) in measuring slip correction factor was about 2 % for the 100.7 nm SRM particles, about 3 % for the 19.90 nm PSL particles, and about 2.5 % for the 269 nm SRM particles. The major sources of uncertainty are the diameter of particles, the geometric constant associated with NDMA, and the voltage. PMID:27308102

A Dynamical Model Reveals Gene Co-Localizations in Nucleus

PubMed Central

Yao, Ye; Lin, Wei; Hennessy, Conor; Fraser, Peter; Feng, Jianfeng

2011-01-01

Co-localization of networks of genes in the nucleus is thought to play an important role in determining gene expression patterns. Based upon experimental data, we built a dynamical model to test whether pure diffusion could account for the observed co-localization of genes within a defined subnuclear region. A simple standard Brownian motion model in two and three dimensions shows that preferential co-localization is possible for co-regulated genes without any direct interaction, and suggests the occurrence may be due to a limitation in the number of available transcription factors. Experimental data of chromatin movements demonstrates that fractional rather than standard Brownian motion is more appropriate to model gene mobilizations, and we tested our dynamical model against recent static experimental data, using a sub-diffusion process by which the genes tend to colocalize more easily. Moreover, in order to compare our model with recently obtained experimental data, we studied the association level between genes and factors, and presented data supporting the validation of this dynamic model. As further applications of our model, we applied it to test against more biological observations. We found that increasing transcription factor number, rather than factory number and nucleus size, might be the reason for decreasing gene co-localization. In the scenario of frequency- or amplitude-modulation of transcription factors, our model predicted that frequency-modulation may increase the co-localization between its targeted genes. PMID:21760760

On the structure-bounded growth processes in plant populations.

PubMed

Kilian, H G; Kazda, M; Király, F; Kaufmann, D; Kemkemer, R; Bartkowiak, D

2010-07-01

If growing cells in plants are considered to be composed of increments (ICs) an extended version of the law of mass action can be formulated. It evidences that growth of plants runs optimal if the reaction-entropy term (entropy times the absolute temperature) matches the contact energy of ICs. Since these energies are small, thermal molecular movements facilitate via relaxation the removal of structure disturbances. Stem diameter distributions exhibit extra fluctuations likely to be caused by permanent constraints. Since the signal-response system enables in principle perfect optimization only within finite-sized cell ensembles, plants comprising relatively large cell numbers form a network of size-limited subsystems. The maximal number of these constituents depends both on genetic and environmental factors. Accounting for logistical structure-dynamics interrelations, equations can be formulated to describe the bimodal growth curves of very different plants. The reproduction of the S-bended growth curves verifies that the relaxation modes with a broad structure-controlled distribution freeze successively until finally growth is fully blocked thus bringing about "continuous solidification".

System-size dependence of open-heavy-flavor production in nucleus-nucleus collisions at √sNN =200 GeV

NASA Astrophysics Data System (ADS)

Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Alexander, J.; Aoki, K.; Apadula, N.; Aphecetche, L.; Armendariz, R.; Aronson, S. H.; Asai, J.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Baksay, G.; Baksay, L.; Baldisseri, A.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Bathe, S.; Batsouli, S.; Baublis, V.; Baumgart, S.; Bazilevsky, A.; Belikov, S.; Bennett, R.; Berdnikov, Y.; Bickley, A. A.; Boissevain, J. G.; Borel, H.; Boyle, K.; Brooks, M. L.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Campbell, S.; Chang, B. S.; Charvet, J.-L.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Chujo, T.; Chung, P.; Churyn, A.; Cianciolo, V.; Cleven, C. R.; Cole, B. A.; Comets, M. P.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Das, K.; David, G.; Deaton, M. B.; Dehmelt, K.; Delagrange, H.; Denisov, A.; D'Enterria, D.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Dion, A.; Donadelli, M.; Drapier, O.; Drees, A.; Dubey, A. K.; Durham, J. M.; Durum, A.; Dzhordzhadze, V.; Efremenko, Y. V.; Egdemir, J.; Ellinghaus, F.; Emam, W. S.; Enokizono, A.; En'yo, H.; Esumi, S.; Eyser, K. O.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Gadrat, S.; Garishvili, I.; Glenn, A.; Gong, H.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Hachiya, T.; Hadj Henni, A.; Haegemann, C.; Haggerty, J. S.; Hamagaki, H.; Han, R.; Harada, H.; Hartouni, E. P.; Haruna, K.; Haslum, E.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Hiejima, H.; Hill, J. C.; Hobbs, R.; Hohlmann, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hornback, D.; Ichihara, T.; Iinuma, H.; Imai, K.; Inaba, M.; Inoue, Y.; Isenhower, D.; Isenhower, L.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Jacak, B. V.; Jia, J.; Jin, J.; Jinnouchi, O.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kaneta, M.; Kang, J. H.; Kanou, H.; Kawall, D.; Kazantsev, A. V.; Khanzadeev, A.; Kikuchi, J.; Kim, D. H.; Kim, D. J.; Kim, E.; Kinney, E.; Kiss, Á.; Kistenev, E.; Kiyomichi, A.; Klay, J.; Klein-Boesing, C.; Kochenda, L.; Kochetkov, V.; Komkov, B.; Konno, M.; Kotchetkov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kubart, J.; Kunde, G. J.; Kurihara, N.; Kurita, K.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, D. M.; Lee, M. K.; Lee, T.; Leitch, M. J.; Leite, M. A. L.; Lenzi, B.; Li, X.; Liška, T.; Litvinenko, A.; Liu, M. X.; Love, B.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mao, Y.; Mašek, L.; Masui, H.; Matathias, F.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; Miake, Y.; Mikeš, P.; Miki, K.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mishra, M.; Mitchell, J. T.; Mitrovski, M.; Morreale, A.; Morrison, D. P.; Moukhanova, T. V.; Mukhopadhyay, D.; Murata, J.; Nagamiya, S.; Nagata, Y.; Nagle, J. L.; Naglis, M.; Nakagawa, I.; Nakamiya, Y.; Nakamura, T.; Nakano, K.; Newby, J.; Nguyen, M.; Norman, B. E.; Nouicer, R.; Nyanin, A. S.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Ohnishi, H.; Oka, M.; Okada, K.; Omiwade, O. O.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pal, D.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, J.; Park, W. J.; Pate, S. F.; Pei, H.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Pinkenburg, C.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reuter, M.; Reygers, K.; Riabov, V.; Riabov, Y.; Roche, G.; Romana, A.; Rosati, M.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Rykov, V. L.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakai, S.; Sakata, H.; Samsonov, V.; Sato, S.; Sawada, S.; Seele, J.; Seidl, R.; Semenov, V.; Seto, R.; Sharma, D.; Shein, I.; Shevel, A.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, C. P.; Singh, V.; Skutnik, S.; Slunečka, M.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Suire, C.; Sziklai, J.; Tabaru, T.; Takagi, S.; Takagui, E. M.; Taketani, A.; Tanaka, Y.; Tanida, K.; Tannenbaum, M. J.; Taranenko, A.; Tarján, P.; Thomas, T. L.; Togawa, M.; Toia, A.; Tojo, J.; Tomášek, L.; Torii, H.; Towell, R. S.; Tram, V.-N.; Tserruya, I.; Tsuchimoto, Y.; Vale, C.; Valle, H.; van Hecke, H. W.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vrba, V.; Vznuzdaev, E.; Wagner, M.; Walker, D.; Wang, X. R.; Watanabe, Y.; Wessels, J.; White, S. N.; Winter, D.; Woody, C. L.; Wysocki, M.; Xie, W.; Yamaguchi, Y. L.; Yanovich, A.; Yasin, Z.; Ying, J.; Yokkaichi, S.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zaudtke, O.; Zhang, C.; Zhou, S.; Zimányi, J.; Zolin, L.; Phenix Collaboration

2014-09-01

The PHENIX Collaboration at the Relativistic Heavy Ion Collider has measured open-heavy-flavor production in Cu +Cu collisions at √sNN =200 GeV through the measurement of electrons at midrapidity that originate from semileptonic decays of charm and bottom hadrons. In peripheral Cu +Cu collisions an enhanced production of electrons is observed relative to p +p collisions scaled by the number of binary collisions. In the transverse momentum range from 1 to 5 GeV/c the nuclear modification factor is RAA˜1.4. As the system size increases to more central Cu +Cu collisions, the enhancement gradually disappears and turns into a suppression. For pT>3 GeV/c, the suppression reaches RAA˜0.8 in the most central collisions. The pT and centrality dependence of RAA in Cu +Cu collisions agree quantitatively with RAA in d +Au and Au +Au collisions, if compared at a similar number of participating nucleons .

Local politics and retail cannabis markets: the case of the Dutch coffeeshops.

PubMed

Wouters, Marije; Benschop, Annemieke; Korf, Dirk J

2010-07-01

Cannabis coffeeshops are concentrated in specific areas in the Netherlands; close to 80% of Dutch municipalities have no coffeeshops. We investigated why such wide local differences exist. Regression analyses were carried out on data regarding the number of coffeeshops per municipality, local council seat distribution and area demographic characteristics. A contrast analysis of municipalities with no/few vs. many coffeeshops was also performed. Whether a town has one or more coffeeshops can be predicted in part by its population size, but more strongly by political composition of the local council. The larger the percentage of progressive councillors, the greater the probability that coffeeshops are allowed. The number of coffeeshops in a town depends primarily on the demand for cannabis (reflected in factors like local population size); it generally has little to do with national-level party political preferences about drug policy. Both the demand for coffeeshops and local political preference influence coffeeshop policy in the Netherlands. Copyright (c) 2010 Elsevier B.V. All rights reserved.

A Rare Allele of GS2 Enhances Grain Size and Grain Yield in Rice.

PubMed

Hu, Jiang; Wang, Yuexing; Fang, Yunxia; Zeng, Longjun; Xu, Jie; Yu, Haiping; Shi, Zhenyuan; Pan, Jiangjie; Zhang, Dong; Kang, Shujing; Zhu, Li; Dong, Guojun; Guo, Longbiao; Zeng, Dali; Zhang, Guangheng; Xie, Lihong; Xiong, Guosheng; Li, Jiayang; Qian, Qian

2015-10-05

Grain size determines grain weight and affects grain quality. Several major quantitative trait loci (QTLs) regulating grain size have been cloned; however, our understanding of the underlying mechanism that regulates the size of rice grains remains fragmentary. Here, we report the cloning and characterization of a dominant QTL, grain size on chromosome 2 (GS2), which encodes Growth-Regulating Factor 4 (OsGRF4), a transcriptional regulator. GS2 localizes to the nucleus and may act as a transcription activator. A rare mutation of GS2 affecting the binding site of a microRNA, OsmiR396c, causes elevated expression of GS2/OsGRF4. The increase in GS2 expression leads to larger cells and increased numbers of cells, which thus enhances grain weight and yield. The introduction of this rare allele of GS2/OsGRF4 into rice cultivars could significantly enhance grain weight and increase grain yield, with possible applications in breeding high-yield rice varieties. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

Assessment of Risk Factors in Patients who presented to the Outpatient Clinic for Breast Cancer-Related Lymphedema

PubMed Central

Can, Aslı Gençay; Ekşioğlu, Emel; Bahtiyarca, Zeynep Tuba; Çakcı, Fatma Aytül

2016-01-01

Objective Lymphedema is one of the most debilitating outcomes of breast cancer treatment. We aimed to compare the demographic and clinical characteristics of breast cancer patients with and without lymphedema, to assess risk factors for lymphedema, and to evaluate treatment outcomes in lymphedema patients. Materials and Methods Demographic and clinical characteristics of 84 women with previous surgery for breast cancer who presented to the outpatient clinic between March 2014 and May 2015 were retrospectively extracted from patient records. Results Upper extremity lymphedema was detected in 34 of 84 patients (40.5%). The mean age, body mass index, the number of positive lymph nodes and the number of patients with postoperative radiotherapy were significantly higher among patients with lymphedema than those without (p<0.05). Educational level of patients with lymphedema was significantly lower than the other group (p<0.05). The correlation analysis revealed an association between age, educational level, body mass index, tumor stage, number of positive lymph nodes, postoperative radiotherapy and presence of lymphedema. Postoperative radiotherapy was detected as the only independent risk factor by logistic regression analysis. Fourteen out of 26 lymphedema patients were assigned to education, skin care, exercise and compression bandaging therapy. Upper extremity volumes and volume differences were significantly improved after treatment. Conclusion Advanced age, low educational level, obesity, tumor size, the number of positive lymph nodes and postoperative radiotherapy correlated with the development of lymphedema. Within these factors, postoperative radiotherapy was detected as an independent risk factor for the development of lymphedema. Patient education, skin care, exercise and compression bandage therapy are effective treatment options in breast cancer-related lymphedema. PMID:28331728

Chronic Sublethal Effects of San Francisco Bay Sediments on Nereis (Neanthes) Arenaceodentata: Non treatment Factors

DTIC Science & Technology

1992-09-01

example, grain size had no effect , while the number of worms added to each expo- sure vessel was critical. Direct transfer from 30 ppt to salinities !515... Effect of Salinity on Juvenile Worms ..................... 13 Effect of Ammonia on Juvenile Worms .................... 14 Resistance of Juvenile Worms to...experimental design used to evaluate salinity effects . Preliminary experiments indicated that nominal ammonia concentrations (0, 2.5, 5.0, 10, 20, and

Vascular Endothelial Growth Factor (VEGF) mRNA Isoforms are Altered in Bovine Granulosa Cells (GC) by Circulating Progestin Concentrations (P4) and May Indicate Follicle Status and Oocyte Competence

USDA-ARS?s Scientific Manuscript database

Previously, Melengestrol Acetate (MGA) fed for 14 d (0.5mg/cow/d; < 1 ng/ml P4) resulted in persistent follicles with increased size, decreased number of GC/follicular fluid (FF) volume, and less fertile oocytes. An experiment was conducted to determine effects of circulating P4 on amount of mRNA fo...

The Coast Artillery Journal. Volume 68, Number 2, February 1928

DTIC Science & Technology

1928-02-01

presentation makes it possible for the uninitated to picture readily a wiring diagram in its full meaning. For those who would compute rapidly, and to a...probably organic army artillery, thus computed , would be better, with, in addition, quotas of G. H. Q. Artillery provided for various sized groups of...the computation of antiaircraft deflections, and it is to satisfy their very natural curiosity with regard particularly to the improving factor and the

Parasitism as the main factor shaping peptide vocabularies in current organisms.

PubMed

Zemková, Michaela; Zahradník, Daniel; Mokrejš, Martin; Flegr, Jaroslav

2017-06-01

Self/non-self-discrimination by vertebrate immune systems is based on the recognition of the presence of peptides in proteins of a parasite that are not contained in the proteins of a host. Therefore, a reduction of the number of 'words' in its own peptide vocabulary could be an efficient evolutionary strategy of parasites for escaping recognition. Here, we compared peptide vocabularies of 30 endoparasitic and 17 free-living unicellular organisms and also eight multicellular parasitic and 16 multicellular free-living organisms. We found that both unicellular and multicellular parasites used a significantly lower number of different pentapeptides than free-living controls. Impoverished pentapeptide vocabularies in parasites were observed across all five clades that contain both the parasitic and free-living species. The effect of parasitism on a number of peptides used in an organism's proteins is larger than effects of all other studied factors, including the size of a proteome, the number of encoded proteins, etc. This decrease of pentapeptide diversity was partly compensated for by an increased number of hexapeptides. Our results support the hypothesis of parasitism-associated reduction of peptide vocabulary and suggest that T-cell receptors mostly recognize the five amino acids-long part of peptides that are presented in the groove of major histocompatibility complex molecules.

The cost of large numbers of hypothesis tests on power, effect size and sample size.

PubMed

Lazzeroni, L C; Ray, A

2012-01-01

Advances in high-throughput biology and computer science are driving an exponential increase in the number of hypothesis tests in genomics and other scientific disciplines. Studies using current genotyping platforms frequently include a million or more tests. In addition to the monetary cost, this increase imposes a statistical cost owing to the multiple testing corrections needed to avoid large numbers of false-positive results. To safeguard against the resulting loss of power, some have suggested sample sizes on the order of tens of thousands that can be impractical for many diseases or may lower the quality of phenotypic measurements. This study examines the relationship between the number of tests on the one hand and power, detectable effect size or required sample size on the other. We show that once the number of tests is large, power can be maintained at a constant level, with comparatively small increases in the effect size or sample size. For example at the 0.05 significance level, a 13% increase in sample size is needed to maintain 80% power for ten million tests compared with one million tests, whereas a 70% increase in sample size is needed for 10 tests compared with a single test. Relative costs are less when measured by increases in the detectable effect size. We provide an interactive Excel calculator to compute power, effect size or sample size when comparing study designs or genome platforms involving different numbers of hypothesis tests. The results are reassuring in an era of extreme multiple testing.