SPRUCE Plant-Available Nutrients Assessed with Ion-Exchange Resins in Experimental Plots, Beginning in 2013

DOE Data Explorer

Iversen, C. M. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Latimer, J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Burnham, A. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Brice, D. J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Childs, J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Vander Stel, H. M. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A

2017-01-01

This data set consists of observations of plant-available nutrients assessed using ion-exchange resin capsules incubated serially in aerobic and anaerobic peat layers beginning in 2013 in the SPRUCE experimental plots at four depths in hummock microtopography and two depths in hollow microtopography. Data will be periodically added to until the conclusion of the SPRUCE experiment.

Nocturnal Near-Surface Temperature, but not Flow Dynamics, can be Predicted by Microtopography in a Mid-Range Mountain Valley

NASA Astrophysics Data System (ADS)

Pfister, Lena; Sigmund, Armin; Olesch, Johannes; Thomas, Christoph K.

2017-11-01

We investigate nocturnal flow dynamics and temperature behaviour near the surface of a 170-m long gentle slope in a mid-range mountain valley. In contrast to many existing studies focusing on locations with significant topographic variations, gentle slopes cover a greater spatial extent of the Earth's surface. Air temperatures were measured using the high-resolution distributed-temperature-sensing method within a two-dimensional fibre-optic array in the lowest metre above the surface. The main objectives are to characterize the spatio-temporal patterns in the near-surface temperature and flow dynamics, and quantify their responses to the microtopography and land cover. For the duration of the experiment, including even clear-sky nights with weak winds and strong radiative forcing, the classical cold-air drainage predicted by theory could not be detected. In contrast, we show that the airflow for the two dominant flow modes originates non-locally. The most abundant flow mode is characterized by vertically-decoupled layers featuring a near-surface flow perpendicular to the slope and strong stable stratification, which contradicts the expectation of a gravity-driven downslope flow of locally produced cold air. Differences in microtopography and land cover clearly affect spatio-temporal temperature perturbations. The second most abundant flow mode is characterized by strong mixing, leading to vertical coupling with airflow directed down the local slope. Here variations of microtopography and land cover lead to negligible near-surface temperature perturbations. We conclude that spatio-temporal temperature perturbations, but not flow dynamics, can be predicted by microtopography, which complicates the prediction of advective-heat components and the existence and dynamics of cold-air pools in gently sloped terrain in the absence of observations.

Wetland Microtopographic Structure is Revealed with Terrestrial Laser Scanning

NASA Astrophysics Data System (ADS)

Diamond, J.; Stovall, A. E.; Mclaughlin, D. L.; Slesak, R.

2017-12-01

Wetland microtopographic structure and its function has been the subject of research for decades, and several investigations suggest that microtopography is generated by autogenic ecohydrologic processes. But due to the difficulty of capturing the true spatial variability of wetland microtopography, many of the hypotheses for self-organization have remained elusive to test. We employ a novel method of Terrestrial Laser Scanning (TLS) that reveals an unprecedented high-resolution (<0.5 cm) glimpse at the true spatial structure of wetland microtopography in 10 black ash (Fraxinus nigra) stands of northern Minnesota, USA. Here we present the first efforts to synthesize this information and show that TLS provides a good representation of real microtopographic structure, where TLS accurately measured hummock height, but occlusion of low points led to a slight negative bias. We further show that TLS can accurately locate microtopographic high points (hummocks), as well as estimate their height and area. Using these new data, we estimate distributions in both microtopographic elevation and hummock area in each wetland and relate these to monitored hydrologic regime; in doing so, we test hypotheses linking emergent microtopographic patterns to putative hydrologic controls. Finally, we discuss future efforts to enumerate consequent influences of microtopography on wetland systems (soil properties and vegetation composition).

Control of cell nucleus shapes via micropillar patterns.

PubMed

Pan, Zhen; Yan, Ce; Peng, Rong; Zhao, Yingchun; He, Yao; Ding, Jiandong

2012-02-01

We herein report a material technique to control the shapes of cell nuclei by the design of the microtopography of substrates to which the cells adhere. Poly(D,L-lactide-co-glycolide) (PLGA) micropillars or micropits of a series of height or depth were fabricated, and some surprising self deformation of the nuclei of bone marrow stromal cells (BMSCs) was found in the case of micropillars with a sufficient height. Despite severe nucleus deformation, BMSCs kept the ability of proliferation and differentiation. We further demonstrated that the shapes of cell nuclei could be regulated by the appropriate micropillar patterns. Besides circular and elliptoid shapes, some unusual nucleus shapes of BMSCs have been achieved, such as square, cross, dumbbell, and asymmetric sphere-protrusion. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Tuning the surface microstructure of titanate coatings on titanium implants for enhancing bioactivity of implants

PubMed Central

Wang, Hui; Lai, Yue-Kun; Zheng, Ru-Yue; Bian, Ye; Zhang, Ke-Qin; Lin, Chang-Jian

2015-01-01

Biological performance of artificial implant materials is closely related to their surface characteristics, such as microtopography, and composition. Therefore, convenient fabrication of artificial implant materials with a cell-friendly surface structure and suitable composition was of great significance for current tissue engineering. In this work, titanate materials with a nanotubular structure were successfully fabricated through a simple chemical treatment. Immersion test in a simulated body fluid and in vitro cell culture were used to evaluate the biological performance of the treated samples. The results demonstrate that the titanate layer with a nanotubular structure on Ti substrates can promote the apatite-inducing ability remarkably and greatly enhance cellular responses. This highlights the potential of such titanate biomaterials with the special nanoscale structure and effective surface composition for biomedical applications such as bone implants. PMID:26089665

Characterization of microtopography and its influence on vegetation patterns in created wetlands

USGS Publications Warehouse

Moser, K.; Ahn, C.; Noe, G.

2007-01-01

Created wetlands are increasingly used to mitigate wetland loss. Thus, identifying wetland creation methods that enhance ecosystem development might increase the likelihood of mitigation success. Noting that the microtopographic variation found in natural wetland settings may not commonly be found in created wetlands, this study explores relationships between induced microtopography, hydrology, and plant species richness/ diversity in non-tidal freshwater wetlands, comparing results from two created wetland complexes with those from a mature reference wetland complex in northern Virginia. Elevation, steel rod oxidation depth, and species cover were measured along replicate multiscale (0.5 m-, 1 m-, 2 m-, and 4 m-diameter) tangentially conjoined circular transects in each wetland. Microtopography was surveyed using a total station and results used to derive three roughness indices: tortuosity, limiting slope, and limiting elevation difference. Steel rod oxidation depth was used to estimate water table depth, with data collected four times during the growing season for each study site. Plant species cover was estimated visually in 0.2 m2 plots surveyed at peak growth and used to assess species richness, diversity, and wetland prevalence index. Differences in each attribute were examined among disked and non-disked created wetlands and compared to a natural wetland as a reference. Disked and non-disked created wetlands differed in microtopography, both in terms of limiting elevation difference and tortuosity. However, both were within the range of microtopography encompassed by natural wetlands. Disked wetlands supported higher plant diversity and species richness than either natural or non-disked wetlands, as well as greater within-site species assemblage variability than non-disked wetlands. Irrespective of creation method, plant diversity in created wetlands was correlated with tortuosity and limiting elevation difference, similar to correlations observed for natural wetlands. Vegetation was more hydrophytic at disked sites than at non-disked sites, and of equivalent wetland indicator status to natural sites, even though all sites appeared comparable in terms of hydrology. Results suggest that disking may enhance vegetation community development, thus better supporting the goals of wetland mitigation. ?? 2007, The Society of Wetland Scientists.

TiO2 -enriched polymeric powder coatings support human mesenchymal cell spreading and osteogenic differentiation.

PubMed

Mozumder, Mohammad Sayem; Zhu, Jesse; Perinpanayagam, Hiran

2011-06-01

Novel polymeric powder coatings (PPC) were prepared by ultrafine powder coating technology and shown to support human mesenchymal cell attachment and growth. PPC surfaces enriched with nano-TiO(2) (nTiO(2)) showed enhanced cellular responses, and were compared to commercially pure titanium (cpTi). After cell attachment and growth, osteogenic differentiation and bone matrix formation ensures osseointegration for implantable biomaterials. Therefore, the objective of this study was to determine if mesenchymal cells grown on PPC could undergo osteogenic differentiation by inducing Runx2 and bone matrix proteins, and then initiate mineralization. Atomic force microscopy revealed intricate three-dimensional micro-topographies, and the measures of nano-roughness and porosity were similar for all PPC surfaces. Scanning electron microscopy showed that the cells attached and spread out over all of the surfaces. After 1 week in osteogenic media, RT-PCR analysis showed the induction of Runx2, the up-regulation of type I collagen, and the initial detection of alkaline phosphatase and bone sialoprotein. After 4 weeks, Alizarin Red staining showed mineral deposition. However, cell spreading and osteogenic differentiation were significantly (P < 0.05) higher on the cpTi controls than on the PPC surfaces. Furthermore, spreading and differentiation were consistently higher on the titanium-enriched PPC-2, -3 and -4 than on the titanium-free PPC-1. Therefore, despite the presence of complex micro-topographies and nano-features, titanium-enrichment enhanced the cellular response, and pure titanium still provided the best substrate. These findings confirm the cytocompatibility of these novel polymeric coatings and suggest that titanium-enrichment and nTiO(2) additives may enhance their performance.

Large sand waves on the Atlantic Outer Continental Shelf around Wilmington Canyon, off Eastern United States

USGS Publications Warehouse

Knebel, H.J.; Folger, D.W.

1976-01-01

New seismic-reflection data show that large sand waves near the head of Wilmington Canyon on the Atlantic Outer Continental Shelf have a spacing of 100-650 m and a relief of 2-9 m. The bedforms trend northwest and are asymmetrical, the steeper slopes being toward the south or west. Vibracore sediments indicate that the waves apparently have formed on a substrate of relict nearshore sediments. Although the age of the original bedforms is unknown, the asymmetry is consistent with the dominant westerly to southerly drift in this area which has been determined by other methods; the asymmetry, therefore, is probably modern. Observations in the sand-wave area from a submersible during August 1975, revealed weak bottom currents, sediment bioturbation, unrippled microtopography, and lack of scour. Thus, the asymmetry may be maintained by periodic water motion, possibly associated with storms or perhaps with flow in the canyon head. ?? 1976.

An interactive survey panel regarding the effects of mice (Microtus spec.) on a young ecosystem

NASA Astrophysics Data System (ADS)

Zaplata, Markus; Maurer, Thomas; Boldt-Burisch, Katja; Schaaf, Wolfgang; Hinz, Christoph

2015-04-01

Apparent disturbance caused by soil megafauna took place for the very first time in 2014, after nine years of spontaneous vegetative succession of the constructed watershed Chicken Creek catchment (6 ha). This watershed was designed to investigate the initial phase of soil and ecosystem development under natural conditions including the detailed study of hydrologic processes and water-substrate-plant-atmosphere interactions. In autumn 2014, we recorded the primarily common vole (Microtus arvalis Pallas) activities (calamity), which altered the microtopography of the substrate surface: We counted mouse holes and diggings (for storage organs) at the same spatial units (permanent plots, >100 # of 5 m × 5 m) where we monitor the vegetation since the onset of the catchment. We are hence capable of analysing the effect of abundant vegetarian mice and biogenic macropores, e.g. on the occurrence and performance of the more than 150 vascular plant species present by comparing the respective coverage in 2013 (the pre-mice year) versus 2014, with or without accounting for the confounding effect of succession. Additionally elaborated insight on the 3-D architecture of the mice underground corridors and the nesting places (in situ) enables to extrapolate mass and volume of the moved substrate and the number of the nests of mice for the whole catchment. We report these results, anticipating a return service: Here, we ask for your expectation regarding the significance of the mice-made disturbance on the vegetation of the young ecosystem.

A Subgrid Approach for Modeling Microtopography Effects on Overland Flow: Application to Polygonal Tundra: Modeling Archive

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

Ahmad Jan; Ethan Coon; Scott Painter

This Modeling Archive is in support of an NGEE Arctic manuscript under review. A new subgrid model was implemented in the Advanced Terrestrial Simulator (ATS) to capture micro-topography effects on surface flow. A comparison of the fine-scale simulations on seven individual ice-wedge polygons and a cluster of polygons was made between the results of the subgrid model and no-subgrid model. Our finding confirms that the effects of small-scale spatial heterogeneities can be captured in the coarsened models. The dataset contains meshes, inputfiles, subgrid parameters used in the simulations. Python scripts for post-processing and files for geometric analyses are also included.

Spatial patterns of ecohydrologic properties on a hillslope-alluvial fan transect, central New Mexico

USGS Publications Warehouse

Bedford, D.R.; Small, E.E.

2008-01-01

Spatial patterns of soil properties are linked to patchy vegetation in arid and semi-arid landscapes. The patterns of soil properties are generally assumed to be linked to the ecohydrological functioning of patchy dryland vegetation ecosystems. We studied the effects of vegetation canopy, its spatial pattern, and landforms on soil properties affecting overland flow and infiltration in shrublands at the Sevilleta National Wildlife Refuge/LTER in central New Mexico, USA. We studied the patterns of microtopography and saturated conductivity (Ksat), and generally found it to be affected by vegetation canopy and pattern, as well as landform type. On gently sloping alluvial fans, both microtopography and Ksat are high under vegetation canopy and decay with distance from plant center. On steeper hillslope landforms, only microtopography was significantly higher under vegetation canopy, while there was no significant difference in Ksat between vegetation and interspaces. Using geostatistics, we found that the spatial pattern of soil properties was determined by the spatial pattern of vegetation. Most importantly, the effects of vegetation were present in the unvegetated interspaces 2-4 times the extent of vegetation canopy, on the order of 2-3??m. Our results have implications for the understanding the ecohydrologic function of semi-arid ecosystems as well as the parameterization of hydrologic models. ?? 2007 Elsevier B.V. All rights reserved.

Changes in micro-relief during different water erosive stages of purple soil under simulated rainfall.

PubMed

Luo, Jian; Zheng, Zicheng; Li, Tingxuan; He, Shuqin

2018-02-22

This study investigated the variation characteristics of micro-topography during successive erosive stages of water erosion: splash erosion (SpE), sheet erosion (ShE), and rill erosion (RE). Micro-topography was quantified using surface elevation change, soil roughness (SR) and multifractal model. Results showed that the area of soil surface elevation decay increased gradually with the development of water erosion. With rainfall, the combined effects of the detachment by raindrop impact and the transport of runoff decreased SR, whereas rill erosion contributed to increase SR. With the increase in slope gradient, soil erosion area gradually decreased at the splash erosion stage. By contrast, soil erosion area initially decreased and then increased at the sheet and rill erosion stages. The width of the D q spectra (ΔD) values increased at the splash erosion stage and then decreased at the sheet and rill erosion stages on the 10° slope, opposite to that on the 15° slope. The ΔD values decreased with the evolution of water erosive stages on the 20° slope. The slope had an enhancing effect on the evolution of water erosion. In this study, we clarified the essence of micro-topography and laid a theoretical foundation for further understanding diverse hydrological processes.

Microtopography enhances nitrogen cycling and removal in created mitigation wetlands

USGS Publications Warehouse

Wolf, K.L.; Ahn, C.; Noe, G.B.

2011-01-01

Natural wetlands often have a heterogeneous soil surface topography, or microtopography (MT), that creates microsites of variable hydrology, vegetation, and soil biogeochemistry. Created mitigation wetlands are designed to mimic natural wetlands in structure and function, and recent mitigation projects have incorporated MT as one way to attain this goal. Microtopography may influence nitrogen (N) cycling in wetlands by providing adjacent areas of aerobic and anaerobic conditions and by increasing carbon storage, which together facilitate N cycling and removal. This study investigated three created wetlands in the Virginia Piedmont that incorporated disking-induced MT during construction. One site had paired disked and undisked plots, allowing an evaluation of the effects of this design feature on N flux rates. Microtopography was measured using conventional survey equipment along a 1-m circular transect and was described using two indices: tortuosity (T), describing soil surface roughness and relief, and limiting elevation difference (LD), describing soil surface relief. Ammonification, nitrification, and net N mineralization were determined with in situ incubation of modified ion-exchange resin cores and denitrification potential was determined using denitrification enzyme assay (DEA). Results demonstrated that disked plots had significantly greater LD than undisked plots one year after construction. Autogenic sources of MT (e.g. tussock-forming vegetation) in concert with variable hydrology and sedimentation maintained and in some cases enhanced MT in study wetlands. Tortuosity and LD values remained the same in one wetland when compared over a two-year period, suggesting a dynamic equilibrium of MT-forming and -eroding processes at play. Microtopography values also increased when comparing the original induced MT of a one-year old wetland with MT of older created wetlands (five and eight years old) with disking-induced MT, indicating that MT can increase by natural processes over time. When examined along a hydrologic gradient, LD increased with proximity to an overflow point as a result of differential sediment deposition and erosion during flood events. Nitrification increased with T and denitrification potential increased with LD, indicating that microtopographic heterogeneity enhances coupled N fluxes. The resulting N flux patterns may be explained by the increase in oxygen availability elicited by greater T (enhancing nitrification) and by the adjacent zones of aerobic and anaerobic conditions elicited by greater LD (enhancing coupled nitrification and denitrification potential). Findings of this study support the incorporation of MT into the design and regulatory evaluation of created wetlands in order to enhance N cycling and removal. ?? 2011.

SPRUCE Representing Northern Peatland Microtopography and Hydrology within the Community Land Model: Modeling Archive

DOE Data Explorer

Shi, X. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Thornton, P. E. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Ricciuto, D. M. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Hanson, P. J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Mao, J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Sebestyen, S. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Griffiths, N. A. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Bisht, G. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.

2016-09-01

Here we provide model code, inputs, outputs and evaluation datasets for a new configuration of the Community Land Model (CLM) for SPRUCE, which includes a fully prognostic water table calculation for SPRUCE. Our structural and process changes to CLM focus on modifications needed to represent the hydrologic cycle of bogs environment with perched water tables, as well as distinct hydrologic dynamics and vegetation communities of the raised hummock and sunken hollow microtopography characteristic of SPRUCE and other peatland bogs. The modified model was parameterized and independently evaluated against observations from an ombrotrophic raised-dome bog in northern Minnesota (S1-Bog), the site for the Spruce and Peatland Responses Under Climatic and Environmental Change experiment (SPRUCE).

Biophysical regulation of epigenetic state and cell reprogramming

NASA Astrophysics Data System (ADS)

Downing, Timothy L.; Soto, Jennifer; Morez, Constant; Houssin, Timothee; Fritz, Ashley; Yuan, Falei; Chu, Julia; Patel, Shyam; Schaffer, David V.; Li, Song

2013-12-01

Biochemical factors can help reprogram somatic cells into pluripotent stem cells, yet the role of biophysical factors during reprogramming is unknown. Here, we show that biophysical cues, in the form of parallel microgrooves on the surface of cell-adhesive substrates, can replace the effects of small-molecule epigenetic modifiers and significantly improve reprogramming efficiency. The mechanism relies on the mechanomodulation of the cells’ epigenetic state. Specifically, decreased histone deacetylase activity and upregulation of the expression of WD repeat domain 5 (WDR5)—a subunit of H3 methyltranferase—by microgrooved surfaces lead to increased histone H3 acetylation and methylation. We also show that microtopography promotes a mesenchymal-to-epithelial transition in adult fibroblasts. Nanofibrous scaffolds with aligned fibre orientation produce effects similar to those produced by microgrooves, suggesting that changes in cell morphology may be responsible for modulation of the epigenetic state. These findings have important implications in cell biology and in the optimization of biomaterials for cell-engineering applications.

Integrated surface/subsurface permafrost thermal hydrology: Model formulation and proof-of-concept simulations

DOE PAGES

Painter, Scott L.; Coon, Ethan T.; Atchley, Adam L.; ...

2016-08-11

The need to understand potential climate impacts and feedbacks in Arctic regions has prompted recent interest in modeling of permafrost dynamics in a warming climate. A new fine-scale integrated surface/subsurface thermal hydrology modeling capability is described and demonstrated in proof-of-concept simulations. The new modeling capability combines a surface energy balance model with recently developed three-dimensional subsurface thermal hydrology models and new models for nonisothermal surface water flows and snow distribution in the microtopography. Surface water flows are modeled using the diffusion wave equation extended to include energy transport and phase change of ponded water. Variation of snow depth in themore » microtopography, physically the result of wind scour, is also modeled heuristically with a diffusion wave equation. The multiple surface and subsurface processes are implemented by leveraging highly parallel community software. Fully integrated thermal hydrology simulations on the tilted open book catchment, an important test case for integrated surface/subsurface flow modeling, are presented. Fine-scale 100-year projections of the integrated permafrost thermal hydrological system on an ice wedge polygon at Barrow Alaska in a warming climate are also presented. Finally, these simulations demonstrate the feasibility of microtopography-resolving, process-rich simulations as a tool to help understand possible future evolution of the carbon-rich Arctic tundra in a warming climate.« less

The use of UAV to document sloping landscapes to produce digital elevation models to examine environmental degradation

NASA Astrophysics Data System (ADS)

Themistocleous, K.; Agapiou, A.; Papadavid, G.; Christoforou, M.; Hadjimitsis, D. G.

2015-10-01

This paper focuses on the use of Unmanned Aerial Vehicles (UAVs) over the study area of Pissouri in Cyprus to document the sloping landscapes of the area. The study area has been affected by overgrazing, which has led to shifts in the vegetation patterns and changing microtopography of the soil. The UAV images were used to generate digital elevation models (DEMs) to examine the changes in microtopography. Next to that orthophotos were used to detect changes in vegetation patterns. The combined data of the digital elevation models and the orthophotos will be used to detect the occurrence of catastrophic shifts and mechanisms for desertification in the study area due to overgrazing. This study is part of the "CASCADE- Catastrophic shifts in dryland" project.

Nonlinear effects of microtopography on macroscopic rainfall-runoff partitioning a the hillslope scale: a modelling study

NASA Astrophysics Data System (ADS)

Caviedes-Voullième, Daniel; Domin, Andrea; Hinz, Christoph

2017-04-01

The quantitative description and prediction of hydrological response of hillslopes or hillslope-scale catchments to rainfall events is becoming evermore relevant. At the hillslope scale, the onset of runoff and the overall rainfall-runoff transformation are controlled by multiple interacting small-scale processes, that, when acting together produce a response described in terms of hydrological variables well-defined at the catchment and hillslope scales. We hypothesize that small scale features such microtopography of the land surface will will govern large scale signatures of temporal runoff evolution. This can be tested directly by numerical modelling of well-defined surface geometries and adequate process description. It requires a modelling approach consistent with fundamental fluid mechanics, well-designed numerical methods, and computational efficiency. In this work, an idealized rectangular domain representing a hillslope with an idealized 2D sinusoidal microtopography is studied by simulating surface water redistribution by means of a 2D diffusive-wave (zero-inertia) shallow water model. By studying more than 500 surfaces and performing extensive sensitivity analysis forced by a single rainfall pulse, the dependency of characteristic hydrological responses to microtopographical properties was assessed. Despite of the simplicity of periodic surface and the rain event, results indicate complex surface flow dynamics during the onset of runoff observed at the macro and micro scales. Macro scale regimes were defined in terms of characteristics hydrograph shapes and those were related to surface geometry. The reference regime was defined for smooth topography and consisted of a simple hydrograph with smoothly rising and falling limbs with an intermediate steady state. In constrast, rough surface geometry yields stepwise rising limbs and shorter steady states. Furthermore, the increase in total infiltration over the whole domain relative to the smooth reference case shows a strong non-linear dependency on slope and the ratio of the characteristic wavelength and amplitude of microtopography. The coupled analysis of spatial and hydrological results also suggests that the hydrological behaviour can be explained by the spatiotemporal variations triggered by surface connectivity. This study significantly extents previous work on 1D domains, as our results reveal complexities that require 2D representation of the runoff processes.

FTO gene variant modulates the neural correlates of visual food perception.

PubMed

Kühn, Anne B; Feis, Delia-Lisa; Schilbach, Leonhard; Kracht, Lutz; Hess, Martin E; Mauer, Jan; Brüning, Jens C; Tittgemeyer, Marc

2016-03-01

Variations in the fat mass and obesity associated (FTO) gene are currently the strongest known genetic factor predisposing humans to non-monogenic obesity. Recent experiments have linked these variants to a broad spectrum of behavioural alterations, including food choice and substance abuse. Yet, the underlying neurobiological mechanisms by which these genetic variations influence body weight remain elusive. Here, we explore the brain structural substrate of the obesity-predisposing rs9939609 T/A variant of the FTO gene in non-obese subjects by means of multivariate classification and use fMRI to investigate genotype-specific differences in neural food-cue reactivity by analysing correlates of a visual food perception task. Our findings demonstrate that MRI-derived measures of morphology along middle and posterior fusiform gyrus (FFG) are highly predictive for FTO at-risk allele carriers, who also show enhanced neural responses elicited by food cues in the same posterior FFG area. In brief, these findings provide first-time evidence for FTO-specific differences in both brain structure and function already in non-obese individuals, thereby contributing to a mechanistic understanding of why FTO is a predisposing factor for obesity. Copyright © 2015 Elsevier Inc. All rights reserved.

Simulating effects of microtopography on wetland specific yield and hydroperiod

USGS Publications Warehouse

Summer, David M.; Wang, Xixi

2011-01-01

Specific yield and hydroperiod have proven to be useful parameters in hydrologic analysis of wetlands. Specific yield is a critical parameter to quantitatively relate hydrologic fluxes (e.g., rainfall, evapotranspiration, and runoff) and water level changes. Hydroperiod measures the temporal variability and frequency of land-surface inundation. Conventionally, hydrologic analyses used these concepts without considering the effects of land surface microtopography and assumed a smoothly-varying land surface. However, these microtopographic effects could result in small-scale variations in land surface inundation and water depth above or below the land surface, which in turn affect ecologic and hydrologic processes of wetlands. The objective of this chapter is to develop a physically-based approach for estimating specific yield and hydroperiod that enables the consideration of microtopographic features of wetlands, and to illustrate the approach at sites in the Florida Everglades. The results indicate that the physically-based approach can better capture the variations of specific yield with water level, in particular when the water level falls between the minimum and maximum land surface elevations. The suggested approach for hydroperiod computation predicted that the wetlands might be completely dry or completely wet much less frequently than suggested by the conventional approach neglecting microtopography. One reasonable generalization may be that the hydroperiod approaches presented in this chapter can be a more accurate prediction tool for water resources management to meet the specific hydroperiod threshold as required by a species of plant or animal of interest.

Anisotropy-based crystalline oxide-on-semiconductor material

DOEpatents

McKee, Rodney Allen; Walker, Frederick Joseph

2000-01-01

A semiconductor structure and device for use in a semiconductor application utilizes a substrate of semiconductor-based material, such as silicon, and a thin film of a crystalline oxide whose unit cells are capable of exhibiting anisotropic behavior overlying the substrate surface. Within the structure, the unit cells of the crystalline oxide are exposed to an in-plane stain which influences the geometric shape of the unit cells and thereby arranges a directional-dependent quality of the unit cells in a predisposed orientation relative to the substrate. This predisposition of the directional-dependent quality of the unit cells enables the device to take beneficial advantage of characteristics of the structure during operation. For example, in the instance in which the crystalline oxide of the structure is a perovskite, a spinel or an oxide of similarly-related cubic structure, the structure can, within an appropriate semiconductor device, exhibit ferroelectric, piezoelectric, pyroelectric, electro-optic, ferromagnetic, antiferromagnetic, magneto-optic or large dielectric properties that synergistically couple to the underlying semiconductor substrate.

Fabrication of a platform to isolate the influences of surface nanotopography from chemistry on bacterial attachment and growth.

PubMed

Pegalajar-Jurado, Adoracion; Easton, Christopher D; Crawford, Russell J; McArthur, Sally L

2015-03-26

Billions of dollars are spent annually worldwide to combat the adverse effects of bacterial attachment and biofilm formation in industries as varied as maritime, food, and health. While advances in the fabrication of antifouling surfaces have been reported recently, a number of the essential aspects responsible for the formation of biofilms remain unresolved, including the important initial stages of bacterial attachment to a substrate surface. The reduction of bacterial attachment to surfaces is a key concept in the prevention or minimization of biofilm formation. The chemical and physical characteristics of both the substrate and bacteria are important in understanding the attachment process, but substrate modification is likely the most practical route to enable the extent of bacterial attachment taking place to be effectively controlled. The microtopography and chemistry of the surface are known to influence bacterial attachment. The role of surface chemistry versus nanotopography and their interplay, however, remain unclear. Most methods used for imparting nanotopographical patterns onto a surface also induce changes in the surface chemistry and vice versa. In this study, the authors combine colloidal lithography and plasma polymerization to fabricate homogeneous, reproducible, and periodic nanotopographies with a controllable surface chemistry. The attachment of Escherichia coli bacteria onto carboxyl (plasma polymerized acrylic acid, ppAAc) and hydrocarbon (plasma polymerized octadiene, ppOct) rich plasma polymer films on either flat or colloidal array surfaces revealed that the surface chemistry plays a critical role in bacterial attachment, whereas the effect of surface nanotopography on the bacterial attachment appears to be more difficult to define. This platform represents a promising approach to allow a greater understanding of the role that surface chemistry and nanotopography play on bacterial attachment and the subsequent biofouling of the surface.

[Corrosion resistant properties of different anodized microtopographies on titanium surfaces].

PubMed

Fangjun, Huo; Li, Xie; Xingye, Tong; Yueting, Wang; Weihua, Guo; Weidong, Tian

2015-12-01

To investigate the corrosion resistant properties of titanium samples prepared by anodic oxidation with different surface morphologies. Pure titanium substrates were treated by anodic oxidation to obtain porous titanium films in micron, submicron, and micron-submicron scales. The surface morphologies, coating cross-sectional morphologies, crystalline structures, and surface roughness of these samples were characterized. Electrochemical technique was used to measure the corrosion potential (Ecorr), current density of corrosion (Icorr), and polarization resistance (Rp) of these samples in a simulated body fluid. Pure titanium could be modified to exhibit different surface morphologies by the anodic oxidation technique. The Tafel curve results showed that the technique can improve the corrosion resistance of pure titanium. Furthermore, the corrosion resistance varied with different surface morphologies. The submicron porous surface sample demonstrated the best corrosion resistance, with maximal Ecorr and Rp and minimal Icorr. Anodic oxidation technology can improve the corrosion resistance of pure titanium in a simulated body fluid. The submicron porous surface sample exhibited the best corrosion resistance because of its small surface area and thick barrier layer.

The influence of microtopography on soil nutrients in created mitigation wetlands

USGS Publications Warehouse

Moser, K.F.; Ahn, C.; Noe, G.B.

2009-01-01

This study explores the relationship between microtopography and soil nutrients (and trace elements), comparing results for created and reference wetlands in Virginia, and examining the effects of disking during wetland creation. Replicate multiscale tangentially conjoined circular transects were used to quantify microtopography both in terms of elevation and by two microtopographic indices. Corresponding soil samples were analyzed for moisture content, total C and N, KCl-extractable NH4-N and NO3-N, and Mehlich-3 extractable P, Ca, Mg, K, Al, Fe, and Mn. Means and variances of soil nutrient/element concentrations were compared between created and natural wetlands and between disked and nondisked created wetlands. Natural sites had higher and more variable soil moisture, higher extractable P and Fe, lower Mn than created wetlands, and comparatively high variability in nutrient concentrations. Disked sites had higher soil moisture, NH4-N, Fe, and Mn than did nondisked sites. Consistently low variances (Levene test for inequality) suggested that nondisked sites had minimal nutrient heterogeneity. Across sites, low P availability was inferred by the molar ratio (Mehlich-3 [P/(Al + Fe)] < 0.06); strong intercorrelations among total C, total N, and extractable Fe, Al, and P suggested that humic-metal-P complexes may be important for P retention and availability. Correlations between nutrient/element concentrations and microtopographic indices suggested increased Mn and decreased K and Al availability with increased surface roughness. Disking appears to enhance water and nutrient retention, as well as nutrient heterogeneity otherwise absent from created wetlands, thus potentially promoting ecosystem development. ?? 2008 Society for Ecological Restoration International.

Quantifying soil surface change in degraded drylands: shrub encroachment and effects of fire and vegetation removal in a desert grassland

USGS Publications Warehouse

Sankey, Joel B.; Ravi, Sujith; Wallace, Cynthia S.A.; Webb, Robert H.; Huxman, Travis E.

2012-01-01

Woody plant encroachment, a worldwide phenomenon, is a major driver of land degradation in desert grasslands. Woody plant encroachment by shrub functional types ultimately leads to the formation of a patchy landscape with fertile shrub patches interspaced with nutrient-depleted bare soil patches. This is considered to be an irreversible process of land and soil degradation. Recent studies have indicated that in the early stages of shrub encroachment, when there is sufficient herbaceous connectivity, fires (prescribed or natural) might provide some reversibility to the shrub encroachment process by negatively affecting shrub demography and homogenizing soil resources across patches within weeks to months after burning. A comprehensive understanding of longer term changes in microtopography and spatial patterning of soil properties following fire in shrub-encroached grasslands is desirable. Here, we investigate the changes in microtopography with LiDAR (light detection and ranging), vegetation recovery, and spatial pattering of soil properties in replicated burned, clipped, and control areas in a shrub-grass transition zone in the northern Chihuahuan Desert four years after prescribed fire or clipping. Results indicate a greater homogeneity in soil, microtopography, and vegetation patterning on burned relative to clipped and control treatments. Findings provide further evidence that disturbance by prescribed fire may allow for reversal of the shrub encroachment process, if the event occurs in the early stages of the vegetation shift. Improved understanding of longer-term effects of fire and associated changes in soil patterning can inform the use and role of fire in the context of changing disturbance regimes and climate.

Microtopography recreation benefits ecosystem restoration

Treesearch

Wei Wei; Liding Chen; Lei Yang; F. Fred Samadani; Ge Sun

2012-01-01

Within the context of global warming and accelerated human activities, the surrounding environments of many terrestrial ecosystems worldwide have become increasingly deteriorated, such that finding suitable methods and effective environmental technology to confront climate change and prevent land degradation is critical to the health and sustainability of the earth. In...

Biofilm attachment reduction on bioinspired, dynamic, micro-wrinkling surfaces

NASA Astrophysics Data System (ADS)

Epstein, Alexander K.; Hong, Donggyoon; Kim, Philseok; Aizenberg, Joanna

2013-09-01

Most bacteria live in multicellular communities known as biofilms that are adherent to surfaces in our environment, from sea beds to plumbing systems. Biofilms are often associated with clinical infections, nosocomial deaths and industrial damage such as bio-corrosion and clogging of pipes. As mature biofilms are extremely challenging to eradicate once formed, prevention is advantageous over treatment. However, conventional surface chemistry strategies are either generally transient, due to chemical masking, or toxic, as in the case of leaching marine antifouling paints. Inspired by the nonfouling skins of echinoderms and other marine organisms, which possess highly dynamic surface structures that mechanically frustrate bio-attachment, we have developed and tested a synthetic platform based on both uniaxial mechanical strain and buckling-induced elastomer microtopography. Bacterial biofilm attachment to the dynamic substrates was studied under an array of parameters, including strain amplitude and timescale (1-100 mm s-1), surface wrinkle length scale, bacterial species and cell geometry, and growth time. The optimal conditions for achieving up to ˜ 80% Pseudomonas aeruginosa biofilm reduction after 24 h growth and ˜ 60% reduction after 48 h were combinatorially elucidated to occur at 20% strain amplitude, a timescale of less than ˜ 5 min between strain cycles and a topography length scale corresponding to the cell dimension of ˜ 1 μm. Divergent effects on the attachment of P. aeruginosa, Staphylococcus aureus and Escherichia coli biofilms showed that the dynamic substrate also provides a new means of species-specific biofilm inhibition, or inversely, selection for a desired type of bacteria, without reliance on any toxic or transient surface chemical treatments.

Functional visual sensitivity to ultraviolet wavelengths in the Pileated Woodpecker (Dryocopus pileatus), and its influence on foraging substrate selection.

PubMed

O'Daniels, Sean T; Kesler, Dylan C; Mihail, Jeanne D; Webb, Elisabeth B; Werner, Scott J

2017-05-15

Most diurnal birds are presumed visually sensitive to near ultraviolet (UV) wavelengths, however, controlled behavioral studies investigating UV sensitivity remain few. Although woodpeckers are important as primary cavity excavators and nuisance animals, published work on their visual systems is limited. We developed a novel foraging-based behavioral assay designed to test UV sensitivity in the Pileated Woodpecker (Dryocopus pileatus). We acclimated 21 wild-caught woodpeckers to foraging for frozen mealworms within 1.2m sections of peeled cedar (Thuja spp.) poles. We then tested the functional significance of UV cues by placing frozen mealworms behind UV-reflective covers, UV-absorptive covers, or decayed red pine substrates within the same 1.2m poles in independent experiments. Behavioral responses were greater toward both UV-reflective and UV-absorptive substrates in three experiments. Study subjects therefore reliably differentiated and attended to two distinct UV conditions of a foraging substrate. Cue-naïve subjects showed a preference for UV-absorptive substrates, suggesting that woodpeckers may be pre-disposed to foraging from such substrates. Behavioral responses were greater toward decayed pine substrates (UV-reflective) than sound pine substrates suggesting that decayed pine can be a useful foraging cue. The finding that cue-naïve subjects selected UV-absorbing foraging substrates has implications for ecological interactions of woodpeckers with fungi. Woodpeckers transport fungal spores, and communication methods analogous to those of plant-pollinator mutualisms (i.e. UV-absorbing patterns) may have evolved to support woodpecker-fungus mutualisms. Published by Elsevier Inc.

Functional visual sensitivity to ultraviolet wavelengths in the Pileated Woodpecker (Dryocopus pileatus), and its influence on foraging substrate selection

USGS Publications Warehouse

O'Daniels, Sean T.; Kesler, Dylan C.; Mihail, Jeanne D.; Webb, Elisabeth B.; Werner, Scott J.

2017-01-01

Most diurnal birds are presumed visually sensitive to near ultraviolet (UV) wavelengths, however, controlled behavioral studies investigating UV sensitivity remain few. Although woodpeckers are important as primary cavity excavators and nuisance animals, published work on their visual systems is limited. We developed a novel foraging-based behavioral assay designed to test UV sensitivity in the Pileated Woodpecker (Dryocopus pileatus). We acclimated 21 wild-caught woodpeckers to foraging for frozen mealworms within 1.2 m sections of peeled cedar (Thuja spp.) poles. We then tested the functional significance of UV cues by placing frozen mealworms behind UV-reflective covers, UV-absorptive covers, or decayed red pine substrates within the same 1.2 m poles in independent experiments. Behavioral responses were greater toward both UV-reflective and UV-absorptive substrates in three experiments. Study subjects therefore reliably differentiated and attended to two distinct UV conditions of a foraging substrate. Cue-naïve subjects showed a preference for UV-absorptive substrates, suggesting that woodpeckers may be pre-disposed to foraging from such substrates. Behavioral responses were greater toward decayed pine substrates (UV-reflective) than sound pine substrates suggesting that decayed pine can be a useful foraging cue. The finding that cue-naïve subjects selected UV-absorbing foraging substrates has implications for ecological interactions of woodpeckers with fungi. Woodpeckers transport fungal spores, and communication methods analogous to those of plant-pollinator mutualisms (i.e. UV-absorbing patterns) may have evolved to support woodpecker-fungus mutualisms.

Long-term eutrophication prompts tradeoffs in nitrous oxide and methane emission in a New England salt marsh

EPA Science Inventory

Eutrophication is a common problem facing urban estuaries and may stimulate changes in microtopography, plant communities, and microbial processes that drive greenhouse gas (GHG) fluxes. Since coastal wetlands are known to sequester abundant carbon and GHGs relative to terrestri...

Insight into sediment transport processes on saline rangeland hillslopes using three-dimensional soil microtopography changes

USDA-ARS?s Scientific Manuscript database

In arid and semi-arid rangeland environments, an accurate understanding of runoff generation and sediment transport processes is key to developing effective management actions and addressing ecosystem response to changes. Yet, many primary processes (namely sheet and splash and concentrated flow ero...

Multiple Beam Interferometry in Elementary Teaching

ERIC Educational Resources Information Center

Tolansky, S.

1970-01-01

Discusses a relatively simple technique for demonstrating multiple beam interferometry. The technique can be applied to measuring (1) radii of curvature of lenses, (2) surface finish of glass, and (3) differential phase change on reflection. Microtopographies, modulated fringe systems and opaque objects may also be observed by this technique.…

Cell-like features imprinted in the physical nano- and micro-topography of the environment modify the responses to anti-cancer drugs of endometrial cancer cells.

PubMed

Tan, Li Hui; Sykes, Peter H; Alkaisi, Maan M; Evans, John J

2017-02-14

Topographical features of cells at nanometre resolution were fabricated in polystyrene. The study investigated the effect of physical topography on the response of cancer cells to the common anticancer drugs, paclitaxel and doxorubicin. Human endometrial cancer cells (Ishikawa) were incubated on substrates containing cell-like features that had been fabricated using our bioimprint methodology to create moulds of cells with positive (convex) and negative (concave) topography. Control cultures were performed on flat substrates. Effects of the drugs on caspase-3 expression, proliferating nuclear antigen (PCNA) expression, cell number and vascular endothelial growth factor (VEGF) secretion were determined. Results revealed that the topography influenced the cell responses in a drug-dependent manner i.e. paclitaxel effects were sensitive to topography differently to those of doxorubicin. In addition, function signalling pathways were sensitive to the detailed topography i.e. positive imprint and negative imprint induced distinct response patterns. The results in this study show for the first time that a culture surface with cell-like topography, that has both nano- and micro-resolution, influences endometrial cancer cell responses to chemotherapy drugs. The effects are dependent on the topography and also on the chemotherapy drug. In particular, the platforms described have potential to provide substrates with high physical relevancy on which to undertake preclinical testing of new drugs. The method also allows for use of different cell types to provide cell-specific topography. The results imply that physical architecture of the cancer cell environment may be a suitable prospective target to enhance clinical activity of traditional drugs. Additionally or alternatively we provide compelling support for the notion that understanding the physical component of the nano- and micro-environment may encourage a redirection of drug development. Further, our observation that the cells distinguish between the different cell-like topographies (positive and negative bioimprints) indicates that a realistic topography is advantageous as growth platforms in experiment design.

The importance of pH and sand substrate in the revegetation of saline non-waterlogged peat fields.

PubMed

Montemayor, Marilou B; Price, Jonathan; Rochefort, Line

2015-11-01

A partially peat-extracted coastal bog contaminated by seawater was barren and required revegetation as a wetland. Peat fields were rectangular in shape, cambered in cross-section profile, and separated by drainage ditches. Common to all peat fields were symmetrical patterns in micro-topography with slopes between differences in elevation. Saline non-waterlogged slopes of ∼5% occurred as a symmetrical pair on each side of the crest of the cambered profile, at one end of each peat field. Three rows were laid across this slope (Top, Middle, and Bottom rows) and transplanted with naturally-growing plant species with their sand substrate, in three experiments, and grown for a year. In the Spartina pectinata experiment, bare root stem sections were also planted. Another experiment was conducted to determine changes in the characteristics of a volume of sand when incubated in saline peat fields. We found the salinity of peat increased with moisture downslope, and pH decreased with increase in salinity. S. pectinata grew best when planted with its sand substrate compared with bare root stem section, and when planted in Bottom rows. Juncus balticus had excellent growth in all rows. Unexpectedly, Festuca rubra that was inconspicuous beneath the J. balticus canopy in the natural donor site grew densely within the J. balticus sods. Agrostis stolonifera grew well but seemed to show intolerance to the surrounding acidic peat by curling up its stolons. The pH of the incubated sand volume was much higher than the surrounding peat. These studies suggest that recognition of plant niches and pH manipulation are important in the revegetation of disturbed Sphagnum peatlands that are found abundantly in the northern hemisphere. Results are also relevant to the reclamation of other disturbed lands. Copyright © 2015 Elsevier Ltd. All rights reserved.

Kcne2 Deletion Creates a Multisystem Syndrome Predisposing to Sudden Cardiac Death

PubMed Central

Hu, Zhaoyang; Kant, Ritu; Anand, Marie; King, Elizabeth C.; Krogh-Madsen, Trine; Christini, David J.; Abbott, Geoffrey W.

2014-01-01

Background Sudden cardiac death (SCD) is the leading global cause of mortality, exhibiting increased incidence in diabetics. Ion channel gene perturbations provide a well-established ventricular arrhythmogenic substrate for SCD. However, most arrhythmia susceptibility genes - including the KCNE2 K+ channel β subunit - are expressed in multiple tissues, suggesting potential multiplex SCD substrates. Methods and Results Using “whole transcript” transcriptomics, we uncovered cardiac angiotensinogen upregulation and remodeling of cardiac angiotensinogen interaction networks in P21 Kcne2−/− mouse pups, and adrenal remodeling consistent with metabolic syndrome in adult Kcne2−/− mice. This led to the discovery that Kcne2 disruption causes multiple acknowledged SCD substrates of extracardiac origin: diabetes, hypercholesterolemia, hyperkalemia, anemia and elevated angiotensin II. Kcne2 deletion was also prerequisite for aging-dependent QT prolongation, ventricular fibrillation and SCD immediately following transient ischemia, and fasting-dependent hypoglycemia, myocardial ischemia and atrioventricular block. Conclusions Disruption of a single, widely expressed arrhythmia susceptibility gene can generate a multisystem syndrome comprising manifold electrical and systemic substrates and triggers of SCD. This paradigm is expected to apply to other arrhythmia susceptibility genes, the majority of which encode ubiquitously expressed ion channel subunits or regulatory proteins. PMID:24403551

Characterisation of soil microtopography effects on runoff and soil erosion rates under simulated rainfall

USDA-ARS?s Scientific Manuscript database

Soil surface roughness is commonly identified as one of the dominant factors governing runoff and interrill erosion. Yet, because of difficulties in acquiring the data, most studies pay little attention to soil surface roughness. This is particularly true for soil erosion models which commonly don't...

Modeling of two-dimensional overland flow in a vegetative filter

Treesearch

Matthew J. Helmers; Dean E. Eisenhauer; Thomas G. Franti; Michael G. Dosskey

2002-01-01

Water transports sediment and other pollutants through vegetative filters. It is often assumed that the overland flow is uniformly distributed across the vegetative filter, but this research indicates otherwise. The objective of this study was to model the two-dimensional overland water flow through a vegetative filter, accounting for variation in microtopography,...

Evaluating the SWAT model for a low-gradient forested watershed in coastal South Carolina

Treesearch

D.M. Amatya; M.K. Jha.

2011-01-01

Modeling the hydrology of low�]gradient forested watersheds on shallow, poorly drained soils of the coastal plain is a challenging task due to complexities in watershed delineation, microtopography, evapotranspiration, runoff generation processes and pathways including flooding and submergence caused by tropical storms, and complexity of vegetation species....

Simulation of Runoff Hydrograph on Soil Surfaces with Different Microtopography Using a Travel Time Method at the Plot Scale

PubMed Central

Zhao, Longshan; Wu, Faqi

2015-01-01

In this study, a simple travel time-based runoff model was proposed to simulate a runoff hydrograph on soil surfaces with different microtopographies. Three main parameters, i.e., rainfall intensity (I), mean flow velocity (v m) and ponding time of depression (t p), were inputted into this model. The soil surface was divided into numerous grid cells, and the flow length of each grid cell (l i) was then calculated from a digital elevation model (DEM). The flow velocity in each grid cell (v i) was derived from the upstream flow accumulation area using v m. The total flow travel time through each grid cell to the surface outlet was the sum of the sum of flow travel times along the flow path (i.e., the sum of l i/v i) and t p. The runoff rate at the slope outlet for each respective travel time was estimated by finding the sum of the rain rate from all contributing cells for all time intervals. The results show positive agreement between the measured and predicted runoff hydrographs. PMID:26103635

Simulation of Runoff Hydrograph on Soil Surfaces with Different Microtopography Using a Travel Time Method at the Plot Scale.

PubMed

Zhao, Longshan; Wu, Faqi

2015-01-01

In this study, a simple travel time-based runoff model was proposed to simulate a runoff hydrograph on soil surfaces with different microtopographies. Three main parameters, i.e., rainfall intensity (I), mean flow velocity (vm) and ponding time of depression (tp), were inputted into this model. The soil surface was divided into numerous grid cells, and the flow length of each grid cell (li) was then calculated from a digital elevation model (DEM). The flow velocity in each grid cell (vi) was derived from the upstream flow accumulation area using vm. The total flow travel time through each grid cell to the surface outlet was the sum of the sum of flow travel times along the flow path (i.e., the sum of li/vi) and tp. The runoff rate at the slope outlet for each respective travel time was estimated by finding the sum of the rain rate from all contributing cells for all time intervals. The results show positive agreement between the measured and predicted runoff hydrographs.

Effects of Unsaturated Microtopography on Nitrate Concentrations in Tundra Ecosystems: Examples from Polygonal Terrain and Degraded Peat Plateaus

NASA Astrophysics Data System (ADS)

Heikoop, J. M.; Arendt, C. A.; Newman, B. D.; Charsley-Groffman, L.; Perkins, G.; Wilson, C. J.; Wullschleger, S.

2017-12-01

Under the auspices of the Next Generation Ecosystem Experiment - Arctic, we have been studying hydrogeochemical signals in Alaskan tundra ecosystems underlain by continuous permafrost (Barrow Environmental Observatory (BEO)) and discontinuous permafrost (Seward Peninsula). The Barrow site comprises largely saturated tundra associated with the low gradient Arctic Coastal Plain. Polygonal microtopography, however, can result in slightly raised areas that are unsaturated. In these areas we have previously demonstrated production and accumulation of nitrate, which, based on nitrate isotopic analysis, derives from microbial degradation. Our Seward Peninsula site is located in a much steeper and generally well-drained watershed. In lower-gradient areas at the top and bottom of the watershed, however, the tundra is generally saturated, likely because of the presence of underlying discontinuous permafrost inhibiting infiltration. These settings also contain microtopographic features, though in the form of degraded peat plateaus surrounded by wet graminoid sag ponds. Despite being very different microtopographic features in a very different setting with distinct vegetation, qualitatively similar nitrate accumulation patterns as seen in polygonal terrain were observed. The highest nitrate pore water concentration observed in an unsaturated peat plateau was approximately 5 mg/L, whereas subsurface pore water concentrations in surrounding sag ponds were generally below the limit of detection. Nitrate isotopes indicate this nitrate results from microbial mineralization and nitrification based on comparison to the nitrate isotopic composition of reduced nitrogen sources in the environment and the oxygen isotope composition of site pore water. Nitrate concentrations were most similar to those found in low-center polygon rims and flat-centered polygon centers at the BEO, but were significantly lower than the maximum concentrations seen in the highest and driest polygonal features, the centers of high-centered polygons. Combined, these results suggest that moisture content is a significant control on nitrate production and accumulation in tundra ecosystems and that unsaturated microtopography represents hot spots for microbial decomposition.

Microtopographic control on the ground thermal regime in ice wedge polygons

NASA Astrophysics Data System (ADS)

Abolt, Charles J.; Young, Michael H.; Atchley, Adam L.; Harp, Dylan R.

2018-06-01

The goal of this research is to constrain the influence of ice wedge polygon microtopography on near-surface ground temperatures. Ice wedge polygon microtopography is prone to rapid deformation in a changing climate, and cracking in the ice wedge depends on thermal conditions at the top of the permafrost; therefore, feedbacks between microtopography and ground temperature can shed light on the potential for future ice wedge cracking in the Arctic. We first report on a year of sub-daily ground temperature observations at 5 depths and 9 locations throughout a cluster of low-centered polygons near Prudhoe Bay, Alaska, and demonstrate that the rims become the coldest zone of the polygon during winter, due to thinner snowpack. We then calibrate a polygon-scale numerical model of coupled thermal and hydrologic processes against this dataset, achieving an RMSE of less than 1.1 °C between observed and simulated ground temperature. Finally, we conduct a sensitivity analysis of the model by systematically manipulating the height of the rims and the depth of the troughs and tracking the effects on ice wedge temperature. The results indicate that winter temperatures in the ice wedge are sensitive to both rim height and trough depth, but more sensitive to rim height. Rims act as preferential outlets of subsurface heat; increasing rim size decreases winter temperatures in the ice wedge. Deeper troughs lead to increased snow entrapment, promoting insulation of the ice wedge. The potential for ice wedge cracking is therefore reduced if rims are destroyed or if troughs subside, due to warmer conditions in the ice wedge. These findings can help explain the origins of secondary ice wedges in modern and ancient polygons. The findings also imply that the potential for re-establishing rims in modern thermokarst-affected terrain will be limited by reduced cracking activity in the ice wedges, even if regional air temperatures stabilize.

RhoA-Mediated Functions in C3H10T1/2 Osteoprogenitors Are Substrate Topography Dependent.

PubMed

Ogino, Yoichiro; Liang, Ruiwei; Mendonça, Daniela B S; Mendonça, Gustavo; Nagasawa, Masako; Koyano, Kiyoshi; Cooper, Lyndon F

2016-03-01

Surface topography broadly influences cellular responses. Adherent cell activities are regulated, in part, by RhoA, a member of the Rho-family of GTPases. In this study, we evaluated the influence of surface topography on RhoA activity and associated cellular functions. The murine mesenchymal stem cell line C3H10T1/2 cells (osteoprogenitor cells) were cultured on titanium substrates with smooth topography (S), microtopography (M), and nanotopography (N) to evaluate the effect of surface topography on RhoA-mediated functions (cell spreading, adhesion, migration, and osteogenic differentiation). The influence of RhoA activity in the context of surface topography was also elucidated using RhoA pharmacologic inhibitor. Following adhesion, M and N adherent cells developed multiple projections, while S adherent cells had flattened and widespread morphology. RhoA inhibitor induced remarkable longer and thinner cytoplasmic projections on all surfaces. Cell adhesion and osteogenic differentiation was topography dependent with S < M and N surfaces. RhoA inhibition increased adhesion on S and M surfaces, but not N surfaces. Cell migration in a wound healing assay was greater on S versus M versus N surfaces and RhoA inhibitor increased S adherent cell migration, but not N adherent cell migration. RhoA inhibitor enhanced osteogenic differentiation in S adherent cells, but not M or N adherent cells. RhoA activity was surface topography roughness dependent (S < M, N). RhoA activity and -mediated functions are influenced by surface topography. Smooth surface adherent cells appear highly sensitive to RhoA function, while nano-scale topography adherent cell may utilize alternative cellular signaling pathway(s) to influence adherent cellular functions regardless of RhoA activity. © 2015 Wiley Periodicals, Inc.

Influence of microtopography on soil chemistry and understory riparian vegetation

Treesearch

Irene M. Unger; Rose-Marie Muzika

2008-01-01

The success of riparian forest restoration efforts depends in part on an understanding of the relationship between soil characteristics and vegetation patterns and how these change with site conditions. To examine these relationships for floodplains in northern Missouri, we chose three unchannelized streams as study areas. A sampling grid was established at two plots...

Streamflow response from an ombrotrophic mire

Treesearch

E.S. Verry; K.N. Brooks; P.K. Barten

1988-01-01

Streamflow response to a rainstorm exceeding a 100-year return interval is documented in relation to the peat profile and microtopography. The water tab1e:discharge relation is corrected for specific yield and found to closely parallel the stage:discharge relationship for a level reservoir for flows up to a 25-year return interval. A faster water table:discharge...

Representing northern peatland microtopography and hydrology within the Community Land Model

Treesearch

X. Shi; P.E. Thornton; D.M. Ricciuto; P J. Hanson; J. Mao; Stephen Sebestyen; N.A. Griffiths; G. Bisht

2015-01-01

Predictive understanding of northern peatland hydrology is a necessary precursor to understanding the fate of massive carbon stores in these systems under the influence of present and future climate change. Current models have begun to address microtopographic controls on peatland hydrology, but none have included a prognostic calculation of peatland water table depth...

Impacts of tracked vehicles on sediment from a desert soil

Treesearch

Erek H. Fuchs; Karl M. Wood; Tim L. Jones; Brent Racher

2003-01-01

Off-road military vehicle traffic is a major consideration in the management of military lands. The objective of this study was to determine the impacts of military tracked M1A1 heavy combat tank vehicles on sediment loss from runoff, surface plant cover, and surface microtopography in a desert military training environment. A randomized block design was used which had...

Vascular and non-vascular plant community response to silvicultural practices and resultant microtopography creation in a forested wetland

Treesearch

Heidi M. Anderson; Margeret R. Gale; Martin F. Jurgensen; Carl C. Trettin

2007-01-01

Forested wetlands are important ecosystems valued for their indigenous plant communities, spatial heterogeneity, wildlife habitat, water quality, and timber resources. When harvested for timber, plant composition in these wetlands may change due to alteration in microsite habitats. Harvest severity also may affect plant composition. In this study, a mineral conifer...

Response of two semiarid grasslands to a second fire application

Treesearch

Carleton S. White; Rosemary L. Pendleton; Burton K. Pendleton

2006-01-01

Prescribed fire was used in two semiarid grasslands to reduce shrub cover, promote grass production, and reduce erosional loss that represents a potential non­point-source of sediment to degrade water quality. This study measured transported soil sediment, dynamics in soil surface microtopography, cover of the woody shrub, grass, and bare ground cover classes, and soil...

A comparison between measured surface microtopography and observed scattering in the extreme ultraviolet

NASA Technical Reports Server (NTRS)

Green, James; Jelinsky, Sharon; Bowyer, Stuart; Malina, Roger F.

1988-01-01

The paper presents comparative measurements of surface roughness on prepared samples. These measurements have been made with both Talystep profilometers and WYKO interferometers. In addition, the scattering distribution from these samples was measured at extreme ultraviolet wavelengths. The utility of the WYKO interferometer and Talystep device for specifying extreme ultraviolet mirror surface quality is discussed.

Micro-Topographies Promote Late Chondrogenic Differentiation Markers in the ATDC5 Cell Line.

PubMed

Le, Bach Q; Vasilevich, Aliaksei; Vermeulen, Steven; Hulshof, Frits; Stamatialis, Dimitrios F; van Blitterswijk, Clemens A; de Boer, Jan

2017-05-01

Chemical and mechanical cues are well-established influencers of in vitro chondrogenic differentiation of ATDC5 cells. Here, we investigate the role of topographical cues in this differentiation process, a study not been explored before. Previously, using a library of surface micro-topographies we found some distinct patterns that induced alkaline phosphatase (ALP) production in human mesenchymal stromal cells. ALP is also a marker for hypertrophy, the end stage of chondrogenic differentiation preceding bone formation. Thus, we hypothesized that these patterns could influence end-stage chondrogenic differentiation of ATDC5 cells. In this study, we randomly selected seven topographies among the ALP influencing hits. Cells grown on these surfaces displayed varying nuclear shape and actin filament structure. When stimulated with insulin-transferrin-selenium (ITS) medium, nodule formation occurred and in some cases showed alignment to the topographical patterns. Gene expression analysis of cells growing on topographical surfaces in the presence of ITS medium revealed a downregulation of early markers and upregulation of late markers of chondrogenic differentiation compared to cells grown on a flat surface. In conclusion, we demonstrated that surface topography in addition to other cues can promote hypertrophic differentiation suitable for bone tissue engineering.

Ecosystem structure and function in the SPRUCE chambers at fine resolution

NASA Astrophysics Data System (ADS)

Glenn, N. F.; Graham, J.; Spaete, L.; Hanson, P. J.

2017-12-01

The Spruce and Peatland Responses Under Climatic and Environmental change (SPRUCE; operated by DOE's Oak Ridge National Laboratory) aims to assess biological and ecological responses in a peat bog to a range of increased temperatures and the presence of elevated atmospheric CO2 concentrations. We are using terrestrial laser scanning (TLS) to monitor vegetation productivity and hummock-hollow structure at cm-scale in the SPRUCE plots to complement in-situ measurements of gross and net primary production. The hummock-hollow peatland microtopography is associated with fluctuating water levels and sphagnum mosses, and ultimately controls C and methane cycling. We estimate tree growth by calculating increases in tree height and canopy voxel volume between years with the TLS data. Microtopography is also characterized over time with TLS but by using gridded cells to classify regions into hummocks or hollows. Spectroscopy to quantify water content in the sphagnum is used to further classify these microtopographic regions. As multiple years of data collection occur, we will couple our fine-scale remote sensing measurements with in-situ measurements of CO2 and CH4 flux measures to capture species-specific productivity responses to warming and increased CO2.

Survival and growth of restored Piedmont riparian forests as affected by site preparation, planting stock, and planting aids

Treesearch

Chelsea M. Curtis; W. Michael Aust; John R. Seiler; Brian D. Strahm

2015-01-01

Forest mitigation sites may have poor survival and growth of planted trees due to poor drainage, compacted soils, and lack of microtopography. The effects of five replications of five forestry mechanical site preparation techniques (Flat, Rip, Bed, Pit, and Mound), four regeneration sources (Direct seed, Bare root, Tubelings, and Gallon), and three planting aids (None...

Hydrology and microtopography control carbon dynamics in wetlands: Implications in partitioning ecosystem respiration in a coastal plain forested wetland

Treesearch

Guofang Miao; Asko Noormets; Jean-Christophe Domec; Montserrat Fuentes; Carl C. Trettin; Ge Sun; Steve G. McNulty; John S. King

2017-01-01

Wetlands store a disproportionately large fraction of organic carbon relative to their areal coverage, and thus play an important role in global climate mitigation. As destabilization of these stores through land use or en- vironmental change represents a signi fi cant climate feedback, it is important to understand the functional regulation of respiratory processes...

Microtopographic Evidence of Hillslope Susceptibility to Active Layer Detachments and Rapid Soil Erosion in Permafrost-dominated Watersheds

NASA Astrophysics Data System (ADS)

Rowland, J. C.; Shelef, E.; Sutfin, N. A.; Piliouras, A.; Andresen, C. G.; Wilson, C. J.

2017-12-01

Movement and storage rates of soil and carbon along permafrost-dominated hillslopes may vary dramatically from long-term steady creeping, at centimeters per year, to rapid gullying, land sliding, and active layer detachments of meter to decimeter sized portions of hillslopes. The rate and drivers of hillslope soil processes may have strong feedbacks on microtopography and hydrology that in turn strongly influence vegetation dynamics and biogeochemistry within watersheds. We observed evidence of both steady soil creep and more catastrophic soil erosion processes occurring across three small watersheds in the southern Seward Peninsula, AK. In these watersheds, we inferred active soil creep processes from the occurrence of solifluction lobes with partially buried shrubs and tilted survey benchmarks on slopes lacking lobes. More dramatic and rapid erosion of soils was evidenced by active layer detachments, extensional cracks in the tundra vegetation, gullying, and both small- and large-scale soil failure scarps. The margins and heads of valley hollows exhibited failure scars up to 4m in height. The spatial distribution of actively eroding areas suggests that some portions of hilllslopes may be more susceptible to rapid erosion. Coring of hillslope soils suggests a possible association between more actively eroding areas and the presence of an ice-rich layer (> 50%) at depths of approximately 90 cm down to the inferred top of bedrock at depths at 170 to 200 cm. We observed that the surface of these hillslope regions appears to have greater microtopographic roughness with a more chaotic and "lumpy" surface than portions of the hillslope were no massive ice layers were encountered. We hypothesize that the extensional cracking and chaotic surface roughness may arise from small-scale soil failures triggered when the seasonal thaw depth intersects the ice-rich layer. It may be possible to identify hillslope regions underlain by ice-rich layers with greater susceptibility for localized erosion and deformation based on a quantitative characterization of the hillslope microtopography. Using drone-based LiDAR topographic data to be acquired in late summer of 2017, we will quantitatively explore the relationship between microtopography and hillslope ice-content.

Formation of tussocks by sedges: effects of hydroperiod and nutrients.

PubMed

Lawrence, Beth A; Zedler, Joy B

2011-07-01

Tussock formation is a global phenomenon that enhances microtopography and increases biodiversity by adding structure to ecological communities, but little is known about tussock development in relation to environmental factors. To further efforts to restore wetland microtopography and associated functions, we investigated Carex stricta tussock size in relation to elevation (a proxy for water depth) at a range of sites in southern Wisconsin, USA, and tested the effect of five hydroperiods and N+P addition (15 g N/m2 + 0.37 g P/m2) on tussock formation during a three-year mesocosm experiment. Wet meadows dominated by C. stricta averaged 4.9 tussocks/m2, with a mean volume of 1160 cm3 and height of 15 cm. Within sites, taller tussocks occurred at lower elevations, suggesting a structural adaptation to anoxic conditions. In our mesocosm experiment, C. stricta accelerated tussock formation when inundated, and it increased overall productivity with N + P addition. Within two growing seasons, continuous inundation (+18 cm) in the mesocosms led to tussocks that were nearly as tall as in our field survey (mean height in mesocosms, 10 +/- 1.3 cm; maximum, 17 cm). Plants grown with constant low water (-18 cm) only formed short mounds (mean height = 2 +/- 0.4 cm). After three growing seasons, the volume of the largest tussocks (3274 +/- 376 cm3, grown with +18 cm water depth and N + P addition) was 12 times that of the smallest (275 +/- 38 cm3, grown with -18 cm water depth and no N + P). Though tussock composition varied among hydroperiods, tussocks were predominantly organic (74-94% of dry mass) and composed of leaf bases (46-59%), fine roots (10-31%), and duff (5-13%). Only the plants subjected to high water levels produced the vertically oriented rhizomes and ascending shoot bases that were prevalent in field-collected tussocks. Under continuous or periodic inundation, tussocks achieved similar heights and accumulated similar levels of organic matter (range: 163-394 g C/m2), and we conclude that these hydroperiods can accelerate tussock formation. Thus, C. stricta has high utility for restoring wetland microtopography and associated functions, including carbon accumulation.

Fine-root growth in a forested bog is seasonally dynamic, but shallowly distributed in nutrient-poor peat

DOE PAGES

Iversen, Colleen M.; Childs, Joanne; Norby, Richard J.; ...

2017-03-30

Fine roots contribute to ecosystem carbon, water, and nutrient fluxes through resource acquisition, respiration, exudation, and turnover, but are understudied in peatlands. Here, we aimed to determine how the amount and timing of fine-root growth in a forested, ombrotrophic bog varied across gradients of vegetation density, peat microtopography, and changes in environmental conditions across the growing season and throughout the peat profile. We quantified fine-root peak standing crop and growth using non-destructive minirhizotron technology over a two-year period, focusing on the dominant woody species in the bog: Picea mariana, Larix laricina, Rhododendron groenlandicum, and Chamaedaphne calyculata. The fine roots ofmore » trees and shrubs were concentrated in raised hummock microtopography, with more tree roots associated with greater tree densities and a unimodal peak in shrub roots at intermediate tree densities. Fine-root growth tended to be seasonally dynamic, but shallowly distributed, in a thin layer of nutrient-poor, aerobic peat above the growing season water table level. Finally, the dynamics and distribution of fine roots in this forested ombrotrophic bog varied across space and time in response to biological, edaphic, and climatic conditions, and we expect these relationships to be sensitive to projected environmental changes in northern peatlands.« less

Spatial models reveal the microclimatic buffering capacity of old-growth forests

PubMed Central

Frey, Sarah J. K.; Hadley, Adam S.; Johnson, Sherri L.; Schulze, Mark; Jones, Julia A.; Betts, Matthew G.

2016-01-01

Climate change is predicted to cause widespread declines in biodiversity, but these predictions are derived from coarse-resolution climate models applied at global scales. Such models lack the capacity to incorporate microclimate variability, which is critical to biodiversity microrefugia. In forested montane regions, microclimate is thought to be influenced by combined effects of elevation, microtopography, and vegetation, but their relative effects at fine spatial scales are poorly known. We used boosted regression trees to model the spatial distribution of fine-scale, under-canopy air temperatures in mountainous terrain. Spatial models predicted observed independent test data well (r = 0.87). As expected, elevation strongly predicted temperatures, but vegetation and microtopography also exerted critical effects. Old-growth vegetation characteristics, measured using LiDAR (light detection and ranging), appeared to have an insulating effect; maximum spring monthly temperatures decreased by 2.5°C across the observed gradient in old-growth structure. These cooling effects across a gradient in forest structure are of similar magnitude to 50-year forecasts of the Intergovernmental Panel on Climate Change and therefore have the potential to mitigate climate warming at local scales. Management strategies to conserve old-growth characteristics and to curb current rates of primary forest loss could maintain microrefugia, enhancing biodiversity persistence in mountainous systems under climate warming. PMID:27152339

Factors associated with premature skin aging (photoaging) before the age of 55: a population-based study.

PubMed

Green, A C; Hughes, M C B; McBride, P; Fourtanier, A

2011-02-01

Precise factors associated with premature skin aging, or photoaging, in the general population are unknown. To examine the risk factors for photoaging in a Queensland community. A cross-sectional study of 1,400 randomly selected residents aged 20-54 years, using casts of the back of the hand (surface microtopography) and dermatological assessment of photoaging. 83% of the participants had premature skin aging, worsening after the age of 30. Severe neck wrinkling was 3 times more likely in men and some 4 times more likely in fair-skinned people (odds ratio, OR=3.86, 95% confidence interval, CI=2.40-6.23). Red hair and mainly outdoor work or leisure raised the odds of microtopographic photoaging. Current smoking was strongly associated with facial comedones and telangiectasia, and among current smokers, the microtopography grade was significantly associated with moderate and heavy smoking measured by pack-years of exposure, with OR=3.18 (95% CI=1.38-7.35) in the heaviest (>20 pack-years) smoking category compared with 1-7 pack-years. Premature skin aging is common in the subtropics, more severe in men and the fair-skinned. It is associated with high sun exposure during leisure or work, and moderate to heavy smoking, and therefore is preventable. Copyright © 2010 S. Karger AG, Basel.

Effects of titanium surface topography on morphology and in vitro activity of human gingival fibroblasts.

PubMed

Ramaglia, L; Capece, G; Di Spigna, G; Bruno, M P; Buonocore, N; Postiglione, L

2013-01-01

The aim of the present study was to evaluate in vitro the biological behavior of human gingival fibroblasts cultured on two different titanium surfaces. Titanium test disks were prepared with a machined, relatively smooth (S) surface or a rough surface (O) obtained by a double acid etching procedure. Primary cultures of human gingival fibroblasts were plated on the experimental titanium disks and cultured up to 14 days. Titanium disk surfaces were analysed by scanning electron microscopy (SEM). Cell proliferation and a quantitative analysis by ELISA in situ of ECM components as CoI, FN and TN were performed. Results have shown different effects of titanium surface microtopography on cell expression and differentiation. At 96 hours of culture on experimental surfaces human gingival fibroblasts displayed a favourable cell attachment and proliferation on both surfaces although showing some differences. Both the relatively smooth and the etched surfaces interacted actively with in vitro cultures of human gingival fibroblasts, promoting cell proliferation and differentiation. Results suggested that the microtopography of a double acid-etched rough surface may induce a greater Co I and FN production, thus conditioning in vivo the biological behaviour of human gingival fibroblasts during the process of peri-implant soft tissue healing.

Advanced in-production hotspot prediction and monitoring with micro-topography

NASA Astrophysics Data System (ADS)

Fanton, P.; Hasan, T.; Lakcher, A.; Le-Gratiet, B.; Prentice, C.; Simiz, J.-G.; La Greca, R.; Depre, L.; Hunsche, S.

2017-03-01

At 28nm technology node and below, hot spot prediction and process window control across production wafers have become increasingly critical to prevent hotspots from becoming yield-limiting defects. We previously established proof of concept for a systematic approach to identify the most critical pattern locations, i.e. hotspots, in a reticle layout by computational lithography and combining process window characteristics of these patterns with across-wafer process variation data to predict where hotspots may become yield impacting defects [1,2]. The current paper establishes the impact of micro-topography on a 28nm metal layer, and its correlation with hotspot best focus variations across a production chip layout. Detailed topography measurements are obtained from an offline tool, and pattern-dependent best focus (BF) shifts are determined from litho simulations that include mask-3D effects. We also establish hotspot metrology and defect verification by SEM image contour extraction and contour analysis. This enables detection of catastrophic defects as well as quantitative characterization of pattern variability, i.e. local and global CD uniformity, across a wafer to establish hotspot defect and variability maps. Finally, we combine defect prediction and verification capabilities for process monitoring by on-product, guided hotspot metrology, i.e. with sampling locations being determined from the defect prediction model and achieved prediction accuracy (capture rate) around 75%

Fine-root growth in a forested bog is seasonally dynamic, but shallowly distributed in nutrient-poor peat

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

Iversen, Colleen M.; Childs, Joanne; Norby, Richard J.

Fine roots contribute to ecosystem carbon, water, and nutrient fluxes through resource acquisition, respiration, exudation, and turnover, but are understudied in peatlands. Here, we aimed to determine how the amount and timing of fine-root growth in a forested, ombrotrophic bog varied across gradients of vegetation density, peat microtopography, and changes in environmental conditions across the growing season and throughout the peat profile. We quantified fine-root peak standing crop and growth using non-destructive minirhizotron technology over a two-year period, focusing on the dominant woody species in the bog: Picea mariana, Larix laricina, Rhododendron groenlandicum, and Chamaedaphne calyculata. The fine roots ofmore » trees and shrubs were concentrated in raised hummock microtopography, with more tree roots associated with greater tree densities and a unimodal peak in shrub roots at intermediate tree densities. Fine-root growth tended to be seasonally dynamic, but shallowly distributed, in a thin layer of nutrient-poor, aerobic peat above the growing season water table level. Finally, the dynamics and distribution of fine roots in this forested ombrotrophic bog varied across space and time in response to biological, edaphic, and climatic conditions, and we expect these relationships to be sensitive to projected environmental changes in northern peatlands.« less

Spatial models reveal the microclimatic buffering capacity of old-growth forests.

PubMed

Frey, Sarah J K; Hadley, Adam S; Johnson, Sherri L; Schulze, Mark; Jones, Julia A; Betts, Matthew G

2016-04-01

Climate change is predicted to cause widespread declines in biodiversity, but these predictions are derived from coarse-resolution climate models applied at global scales. Such models lack the capacity to incorporate microclimate variability, which is critical to biodiversity microrefugia. In forested montane regions, microclimate is thought to be influenced by combined effects of elevation, microtopography, and vegetation, but their relative effects at fine spatial scales are poorly known. We used boosted regression trees to model the spatial distribution of fine-scale, under-canopy air temperatures in mountainous terrain. Spatial models predicted observed independent test data well (r = 0.87). As expected, elevation strongly predicted temperatures, but vegetation and microtopography also exerted critical effects. Old-growth vegetation characteristics, measured using LiDAR (light detection and ranging), appeared to have an insulating effect; maximum spring monthly temperatures decreased by 2.5°C across the observed gradient in old-growth structure. These cooling effects across a gradient in forest structure are of similar magnitude to 50-year forecasts of the Intergovernmental Panel on Climate Change and therefore have the potential to mitigate climate warming at local scales. Management strategies to conserve old-growth characteristics and to curb current rates of primary forest loss could maintain microrefugia, enhancing biodiversity persistence in mountainous systems under climate warming.

Disturbance metrics predict a wetland Vegetation Index of Biotic Integrity

USGS Publications Warehouse

Stapanian, Martin A.; Mack, John; Adams, Jean V.; Gara, Brian; Micacchion, Mick

2013-01-01

Indices of biological integrity of wetlands based on vascular plants (VIBIs) have been developed in many areas in the USA. Knowledge of the best predictors of VIBIs would enable management agencies to make better decisions regarding mitigation site selection and performance monitoring criteria. We use a novel statistical technique to develop predictive models for an established index of wetland vegetation integrity (Ohio VIBI), using as independent variables 20 indices and metrics of habitat quality, wetland disturbance, and buffer area land use from 149 wetlands in Ohio, USA. For emergent and forest wetlands, predictive models explained 61% and 54% of the variability, respectively, in Ohio VIBI scores. In both cases the most important predictor of Ohio VIBI score was a metric that assessed habitat alteration and development in the wetland. Of secondary importance as a predictor was a metric that assessed microtopography, interspersion, and quality of vegetation communities in the wetland. Metrics and indices assessing disturbance and land use of the buffer area were generally poor predictors of Ohio VIBI scores. Our results suggest that vegetation integrity of emergent and forest wetlands could be most directly enhanced by minimizing substrate and habitat disturbance within the wetland. Such efforts could include reducing or eliminating any practices that disturb the soil profile, such as nutrient enrichment from adjacent farm land, mowing, grazing, or cutting or removing woody plants.

Management and Case Outcome of Gastric Impaction in Four Raptors: A Case Series.

PubMed

Applegate, Jeffrey R; Van Wettere, Arnaud; Christiansen, Emily F; Degernes, Laurel A

2017-03-01

Four captive raptors, an American kestrel ( Falco sparverius ), peregrine falcon ( Falco peregrinus ), golden eagle ( Aquila chrysaetos ), and barn owl ( Tyto alba ), were diagnosed with ventricular and/or proventricular foreign material impactions consisting of artificial turf substrate, paper and plastic substrate, grass, and newspaper. Partial or total anorexia was reported in all birds and decreased casting in 2 birds. Survey radiographs confirmed presence of gastric enlargement in all 4 birds. The kestrel and eagle were treated unsuccessfully with gastroscopy and gastric lavage, respectively, followed by surgical intervention to remove the ventricular impactions. Both birds died of undetermined causes after surgery. The peregrine falcon died before medical or surgical intervention was started, and the owl was managed successfully with oral mineral oil and liquid diet to facilitate egestion of the foreign material as a pellet. Lead poisoning was suspected as the predisposing cause for foreign body ingestion in the eagle, but underlying causes for pica in the other birds were not determined. Radiographs can provide useful diagnostic information in sick raptors that exhibit vomiting or changes in appetite or casting frequency, and may help guide treatment decisions of impacted birds. Careful consideration of substrate, enrichment items, and access to potential foreign material that could be ingested may be the best pre-emptive management strategy in captive raptors.

SPRUCE S1 Bog Plant-Available Nutrients Assessed with Ion-Exchange Resins from 2011-2012 in the Southern End of the S1 Bog

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

Iversen, C. M.; Ontl, T. A.; Brice, D. J.

This data set consists of observations of plant-available nutrients assessed using ion-exchange resin capsules incubated serially in aerobic and anaerobic peat layers beginning in 2011. Data were collected from 2011 to 2012 (prior to the construction of the SPRUCE experimental plots) at the southern end of the S1 Bog at three depths in hollow microtopography only.

Nutrient Addition Leads to a Weaker CO2 Sink and Higher CH4 Emissions through Vegetation-Microclimate Feedbacks at Mer Bleue Bog, Canada

NASA Astrophysics Data System (ADS)

Bubier, J. L.; Arnkil, S.; Humphreys, E.; Juutinen, S.; Larmola, T.; Moore, T. R.

2015-12-01

Atmospheric nitrogen (N) deposition has led to nutrient enrichment in wetlands globally, affecting plant community composition, carbon (C) cycling, and microbial dynamics. Nutrient-limited boreal bogs are long-term sinks of carbon dioxide (CO2), but sources of methane (CH4), an important greenhouse gas. We fertilized Mer Bleue Bog, a Sphagnum moss and evergreen shrub-dominated ombrotrophic bog near Ottawa, Ontario, for 10-15 years with N as NO3 and NH4 at 5, 10 and 20 times ambient N deposition (0.6-0.8 g N m-2 y-1), with and without phosphorus (P) and potassium (K). Treatments were applied to triplicate plots (3 x 3 m) from May - August 2000-2015 and control plots received distilled water. We measured net ecosystem CO2 exchange (NEE), ecosystem photosynthesis and respiration, and CH4 flux with climate-controlled chambers; leaf-level CO2 exchange and biochemistry; substrate-induced respiration, CH4 production and consumption potentials with laboratory incubations; plant species composition and abundance; and microclimate (peat temperature, moisture, light interception). After 15 years, we have found that NEE has decreased, and CH4 emissions have increased, in the highest nutrient treatments owing to changes in vegetation, microtopography, and peat characteristics. Vegetation changes include a loss of Sphagnum moss and introduction of new deciduous species. Simulated atmospheric N deposition has not benefitted the photosynthetic apparatus of the dominant evergreen shrubs, but resulted in higher foliar respiration, contributing to a weaker ecosystem CO2 sink. Loss of moss has led to wetter near-surface substrate, higher rates of decomposition and CH4 emission, and a shift in microbial communities. Thus, elevated atmospheric deposition of nutrients may endanger C storage in peatlands through a complex suite of feedbacks and interactions among vegetation, microclimate, and microbial communities.

Using mm-scale seafloor roughness to improve monitoring of macrobenthos by remote sensing

NASA Astrophysics Data System (ADS)

Feldens, Peter; Schönke, Mischa; Wilken, Dennis; Papenmeier, Svenja

2017-04-01

In this study, we determine seafloor roughness at mm-scales by laser line-scanning to improve the remote marine habitat monitoring of macrobenthic organisms. Towards this purpose, a new autonomous lander system has been developed. Remote sensing of the seafloor is required to obtain a comprehensive view of the marine environment. It allows for analyzing spatiotemporal dynamics, monitoring of natural seabed variations, and evaluating possible anthropogenic impacts, all being crucial in regard to marine spatial planning as well as the sustainable and economic use of the sea. One aspect of ongoing remote sensing research is the identification of marine life, including both fauna and flora. The monitoring of seafloor fauna - including benthic communities - is mainly done using optical imaging systems and sample retrieval. The identification of new remote sensing indicator variables characteristic for the physical nature of the respective habitat would allow an improved spatial monitoring. A poorly investigated indicator variable is mm-scale seafloor microtopography and -roughness, which can be measured by laser line scanning and in turn strongly affects acoustic scatter. Two field campaigns have been conducted offshore Sylt Island in 2015 and 2016 to measure the microtopography of seafloor covered by sand masons, blue mussels, and oysters and to collect multi-frequency acoustic data. The acoustic data and topography of the blue mussel and oyster fields are currently being analyzed. The mm-scale microtopography of sand mason covered seafloor were transformed into the frequency domain and the average of the magnitude at different spatial wavelengths was used as a measure of roughness. The presence of sand masons causes a measurable difference in roughness magnitude at spatial wavelengths between 0.02 m and 0.0036 m, with the magnitude depending on sand mason abundance. This effect was not detected by commonly used 1D roughness profiles but required consideration of the complete spectrum. The influenced spatial wavelengths correspond to acoustic frequencies of 75 kHz and 400 kHz that are common for acoustic monitoring purposes. The available results indicate that the development of habitat-specific indicator variables, e.g. related to the abundance of sand masons or mussels, is possible and that remote sensing may assist the monitoring of benthic habitats in the future.

Landscape biogeochemistry reflected in shifting distributions of chemical traits in the Amazon forest canopy

NASA Astrophysics Data System (ADS)

Asner, Gregory P.; Anderson, Christopher B.; Martin, Roberta E.; Tupayachi, Raul; Knapp, David E.; Sinca, Felipe

2015-07-01

Tropical forest functional diversity, which is a measure of the diversity of organismal interactions with the environment, is poorly understood despite its importance for linking evolutionary biology to ecosystem biogeochemistry. Functional diversity is reflected in functional traits such as the concentrations of different compounds in leaves or the density of leaf mass, which are related to plant activities such as plant defence, nutrient cycling, or growth. In the Amazonian lowlands, river movement and microtopography control nutrient mobility, which may influence functional trait distributions. Here we use airborne laser-guided imaging spectroscopy to develop maps of 16 forest canopy traits, throughout four large landscapes that harbour three common forest community types on the Madre de Dios and Tambopata rivers in southwestern Amazonia. Our maps, which are based on quantitative chemometric analysis of forest canopies with visible-to-near infrared (400-2,500 nm) spectroscopy, reveal substantial variation in canopy traits and their distributions within and among forested landscapes. Forest canopy trait distributions are arranged in a nested pattern, with location along rivers controlling trait variation between different landscapes, and microtopography controlling trait variation within landscapes. We suggest that processes of nutrient deposition and depletion drive increasing phosphorus limitation, and a corresponding increase in plant defence, in an eastward direction from the base of the Andes into the Amazon Basin.

The adsorption of oleate on powellite and fluorapatite: A joint experimental and theoretical simulation study

NASA Astrophysics Data System (ADS)

Zhen, Wang

2017-07-01

Flotation and adsorption performance of sodium oleate(NaOl)on powellite and fluorapatite were investigated in this work through micro-flotation tests, work of adhesion calculations, molecular dynamics simulation, micro-topography studies and FTIR measurements. The micro-flotation results show a similar flotation behaviors of powellite and fluorapatite under alkaline conditions, but a considerable difference in mineral recoveries in the pH range 2-7, which demonstrates the possibilities for separating powillite from fluorapatite under acidic conditions. The great difference in mineral recovery displays a good accordance with the obvious difference in the work of adhesion of powellite and fluorapatite at NaOl dosage range of 40-80 mg/L, obtained from flotation and contact angle measurements, respectively. The more negative interaction energy (ΔE) between NaOl and powellite/water interface from molecular dynamics simulation reveals a more easily adsorption of NaOl onto powellite than onto fluorapatite, which excellently matches with the results of flotation and work of adhesion. The results of micro-topography study shows that the adsorption of NaOl on powellite is mainly ascribed to the chemisorption of oleate ions with Ca2+ on powellite lattice or the precipitation of calcium dioleate agglomerates on powellite surface when it was in the solution without or with Ca2+, respectively. The FTIR measurements further confirm the chemisorption of oleate ions with Ca2+ active sites on powellite surface.

Long-term impacts of peatland restoration on the net ecosystem exchange (NEE) of blanket bogs in Northern Scotland.

NASA Astrophysics Data System (ADS)

Hambley, Graham; Hill, Timothy; Saunders, Matthew; Arn Teh, Yit

2016-04-01

Unmanaged peatlands represent an important long-term C sink and thus play an important part of the global C cycle. Despite covering only 12 % of the UK land area, peatlands are estimated to store approximately 20 times more carbon than the UK's forests, which cover 13% of the land area. The Flow Country of Northern Scotland is the largest area of contiguous blanket bog in the UK, and one of the biggest in Europe, covering an area in excess of 4000 km2 and plays a key role in mediating regional atmospheric exchanges of greenhouse gases (GHGs) such as carbon dioxide (CO2), and water vapour (H2O). However, these peatlands underwent significant afforestation in the 1980s, when over 670 km2 of blanket bog were drained and planted with Sitka spruce (Picea sitchensis) and Lodgepole pine (Pinus contorta). This resulted in modifications to hydrology, micro-topography, vegetation and soil properties all of which are known to influence the production, emission and sequestration of key GHGs. Since the late 1990s restoration work has been carried out to remove forest plantations and raise water tables, by drain blocking, to encourage the recolonisation of Sphagnum species and restore ecosystem functioning. Here, we report findings of NEE and its constituent fluxes, GPP and Reco, from a study investigating the impacts of restoration on C dynamics over a chronosequence of restored peatlands. The research explored the role of environmental variables and microtopography in modulating land-atmosphere exchanges, using a multi-scale sampling approach that incorporated eddy covariance measurements with dynamic flux chambers. Key age classes sampled included an undrained peatland; an older restored peatland (17 years old); and a more recently restored site (12 years old). The oldest restored site showed the strongest uptake of C, with an annual assimilation rate of 858 g C m-2 yr-1 compared to assimilation rates of 501g C m-2 yr-1 and 575g C m-2 yr-1 from the younger restored site and undrained sites, respectively. Although the oldest restored site had the highest assimilation rate, it was also associated with the highest Reco rate (846 g C m-2 yr-1), while the younger restoration site had a smaller Reco rate of 581 g C m-2 yr-1. The lowest Reco rates were observed at the undrained site (461 g C m-2 yr-1). Observed differences in these rates are driven by differences in temperature and soil moisture content associated with man-made microtopography. Thus, although peatland restoration in this region actively increases CO2 assimilation it also enhances Reco due to the presence of man-made microtopographic features. Although restoration results in peatland ecosystem functioning beginning to return to these sites after 17 years, these data suggest that more aggressive restoration practices (e.g. re-levelling of the soil surface to restore the original peatland microtopography) are required to reinstate C flux rates that are comparable to unmanaged peatlands. Further longer-term observational data are also required to better model and predict the recovery trajectory of these restored ecosystems at multi-decadal timescales, and in order to produce more robust ecosystem carbon budgets.

3D Micro-topography of Transferred Laboratory and Natural Ice Crystal Surfaces Imaged by Cryo and Environmental Scanning Electron Microscopy

NASA Astrophysics Data System (ADS)

Magee, N. B.; Boaggio, K.; Bancroft, L.; Bandamede, M.

2015-12-01

Recent work has highlighted micro-scale roughness on the surfaces of ice crystals grown and imaged in-situ within the chambers of environmental scanning electron microscopes (ESEM). These observations appear to align with theoretical and satellite observations that suggest a prevalence of rough ice in cirrus clouds. However, the atmospheric application of the lab observations are indeterminate because the observations have been based only on crystals grown on substrates and in pure-water vapor environments. In this work, we present details and results from the development of a transfer technique which allows natural and lab-grown ice and snow crystals to be captured, preserved, and transferred into the ESEM for 3D imaging. Ice crystals were gathered from 1) natural snow, 2) a balloon-borne cirrus particle capture device, and 3) lab-grown ice crystals from a diffusion chamber. Ice crystals were captured in a pre-conditioned small-volume (~1 cm3) cryo-containment cell. The cell was then sealed closed and transferred to a specially-designed cryogenic dewer (filled with liquid nitrogen or crushed dry ice) for transport to a new Hitachi Field Emission, Variable Pressure SEM (SU-5000). The cryo-cell was then removed from the dewer and quickly placed onto the pre-conditioned cryo transfer stage attached to the ESEM (Quorum 3010T). Quantitative 3D topographical digital elevation models of ice surfaces are reported from SEM for the first time, including a variety of objective measures of statistical surface roughness. The surfaces of the transported crystals clearly exhibit signatures of mesoscopic roughening that are similar to examples of roughness seen in ESEM-grown crystals. For most transported crystals, the habits and crystal edges are more intricate that those observed for ice grown directly on substrates within the ESEM chamber. Portions of some crystals do appear smooth even at magnification greater than 1000x, a rare observation in our ESEM-grown crystals. The transported crystals hint at some significant differences in roughness morphology, but they do provide evidence that crystals grown in air/water mixtures and with minimal substrate influence also exhibit mesoscopic roughness with similarity to that observed in ESEM-grown crystals.

How sedge meadow soils, microtopography, and vegetation respond to sedimentation

USGS Publications Warehouse

Werner, K.J.; Zedler, Joy B.

2002-01-01

The expansion of urban and agricultural activities in watersheds of the Midwestern USA facilitates the conversion of species-rich sedge meadows to stands of Phalaris arundinacea and Typha spp. We document the role of sediment accumulation in this process based on field surveys of three sedge meadows dominated by Carex stricta, their adjacent Phalaris or Typha stands, and transitions from Carex to these invasive species. The complex microtopography of Carex tussocks facilitates the occurrence of other native species. Tussock surface area and species richness were positively correlated in two marshes (r2 = 0.57 and 0.41); on average, a 33-cm-tall tussock supported 7.6 species. Phalaris also grew in tussock form in wetter areas but did not support native species. We found an average of 10.5 Carex tussocks per 10-m transect, but only 3.5 Phalaris tussocks. Microtopographic relief, determined with a high-precision GPS, measured 11% greater in Carex meadows than Phalaris stands. Inflowing sediments reduced microtopographic variation and surface area for native species. We calculated a loss of one species per 1000 cm2 of lost tussock surface area, and loss of 1.2 species for every 10-cm addition of sediment over the sedge meadow surface. Alluvium overlying the sedge meadow soil had a smaller proportion of organic matter content and higher dry bulk density than the buried histic materials. We conclude that sedimentation contributes to the loss of native species in remnant wetlands. ?? 2002, The Society of Wetland Scientists.

UAV Remote Sensing Can Reveal the Effects of Low-Impact Seismic Lines on Surface Morphology, Hydrology, and Methane (CH4) Release in a Boreal Treed Bog

NASA Astrophysics Data System (ADS)

Lovitt, J.; Rahman, M. M.; Saraswati, S.; McDermid, G. J.; Strack, M.; Xu, B.

2018-03-01

Peatlands are globally significant stores of soil carbon, where local methane (CH4) emissions are strongly linked to water table position and microtopography. Historically, these factors have been difficult to measure in the field, constraining our capacity to observe local patterns of variability. In this paper, we show how remote sensing surveys conducted from unmanned aerial vehicle (UAV) platforms can be used to map microtopography and depth to water over large areas with good accuracy, paving the way for spatially explicit estimates of CH4 emissions. This approach enabled us to observe—for the first time—the effects of low-impact seismic lines (LIS; petroleum exploration corridors) on surface morphology and CH4 emissions in a treed-bog ecosystem in northern Alberta, Canada. Through compaction, LIS lines were found to flatten the observed range in microtopographic elevation by 46 cm and decrease mean depth to water by 15.4 cm, compared to surrounding undisturbed conditions. These alterations are projected to increase CH4 emissions by 20-120% relative to undisturbed areas in our study area, which translates to a total rise of 0.011-0.027 kg CH4 day-1 per linear kilometer of LIS ( 2 m wide). The 16 km of LIS present at our 61 ha study site were predicted to boost CH4 emissions by 20-70 kg between May and September 2016.

Tunable Microfibers Suppress Fibrotic Encapsulation via Inhibition of TGFβ Signaling

PubMed Central

Allen, Jessica; Ryu, Jubin; Maggi, Alessandro; Flores, Bianca; Greer, Julia R.

2016-01-01

Fibrotic encapsulation limits the efficacy and lifetime of implantable biomedical devices. Microtopography has shown promise in the regulation of myofibroblast differentiation, a key driver of fibrotic encapsulation. However, existing studies have not systematically isolated the requisite geometric parameters for suppression of myofibroblast differentiation via microtopography, and there has not been in vivo validation of this technology to date. To address these issues, a novel lamination method was developed to afford more control over topography dimensions. Specifically, in this study we focus on fiber length and its effect on myofibroblast differentiation. Fibroblasts cultured on films with microfibers exceeding 16 μm in length lost the characteristic morphology associated with myofibroblast differentiation, while shorter microfibers of 6 μm length failed to produce this phenotype. This increase in length corresponded to a 50% decrease in fiber stiffness, which acts as a mechanical cue to influence myofibroblast differentiation. Longer microfiber films suppressed expression of myofibroblast-specific genes (αSMA, Col1α2, and Col3α1) and TGFβ signaling components (TGFβ1, TβR2, and Smad3). About 16 μm long microfiber films subcutaneously implanted in a mouse wound-healing model generated a substantially thinner fibrotic capsule and less deposition of collagen in the wound bed. Together, these results identify a critical feature length threshold for microscale topography-mediated repression of fibrotic encapsulation. This study also demonstrates a simple and powerful strategy to improve surface biocompatibility and reduce fibrotic encapsulation around implanted materials. PMID:26507808

The effect of water table fluctuation on soil respiration in a lower coastal plain forested wetland in the southeastern U.S.

NASA Astrophysics Data System (ADS)

Miao, Guofang; Noormets, Asko; Domec, Jean-Christophe; Trettin, Carl C.; McNulty, Steve G.; Sun, Ge; King, John S.

2013-12-01

and environmental pressures on wetland hydrology may trigger changes in carbon (C) cycling, potentially exposing vast amounts of soil C to rapid decomposition. We measured soil CO2 efflux (Rs) continuously from 2009 to 2010 in a lower coastal plain forested wetland in North Carolina, U.S., to characterize its main environmental drivers. To understand and quantify the spatial variation due to microtopography and associated differences in hydrology, measurements were conducted at three microsites along a microtopographic gradient. The seasonal hysteresis in Rs differed by microtopographic location and was caused by the transitions between flooded and nonflooded conditions. Because flooded Rs was small, we reported Rs dynamics mainly during nonflooded periods. A nested model, modified from conventional Q10 (temperature sensitivity) model with dynamic parameters, provided a significantly better simulation on the observed variation of Rs. The model performed better with daily data, indicating that soil temperature (Ts) and water table depth (WTD) were the primary drivers for seasonal variation. The diel variation of Rs was high and independent of Ts and WTD, which both had small diel variations, suggesting the likely association with plant activity. Overall, the site-average soil CO2 efflux was approximately 960-1103 g C m-2 yr-1 in 2010, of which 93% was released during nonflooded periods. Our study indicates that Rs is highly linked to hydroperiod and microtopography in forested wetlands and droughts in wetlands will accelerate soil C loss.

Immune Modulation in the Treatment of Amyotrophic Lateral Sclerosis: A Review of Clinical Trials

PubMed Central

Khalid, Syed I.; Ampie, Leonel; Kelly, Ryan; Ladha, Shafeeq S.; Dardis, Christopher

2017-01-01

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by the degeneration of motor neurons. Though many molecular and genetic causes are thought to serve as predisposing or disease propagating factors, the underlying pathogenesis of the disease is not known. Recent discoveries have demonstrated the presence of inflammation propagating substrates in the central nervous system of patients afflicted with ALS. Over the past decade, this hypothesis has incited an effort to better understand the role of the immune system in ALS and has led to the trial of several potential immune-modulating therapies. Here, we briefly review advances in the role of such therapies. The clinical trials discussed here are currently ongoing or have been concluded at the time of writing. PMID:28993751

Neural substrates of trait impulsivity, anhedonia, and irritability: Mechanisms of heterotypic comorbidity between externalizing disorders and unipolar depression.

PubMed

Zisner, Aimee; Beauchaine, Theodore P

2016-11-01

Trait impulsivity, which is often defined as a strong preference for immediate over delayed rewards and results in behaviors that are socially inappropriate, maladaptive, and short-sighted, is a predisposing vulnerability to all externalizing spectrum disorders. In contrast, anhedonia is characterized by chronically low motivation and reduced capacity to experience pleasure, and is common to depressive disorders. Although externalizing and depressive disorders have virtually nonoverlapping diagnostic criteria in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, heterotypic comorbidity between them is common. Here, we review common neural substrates of trait impulsivity, anhedonia, and irritability, which include both low tonic mesolimbic dopamine activity and low phasic mesolimbic dopamine responding to incentives during reward anticipation and associative learning. We also consider how other neural networks, including bottom-up emotion generation systems and top-down emotion regulation systems, interact with mesolimbic dysfunction to result in alternative manifestations of psychiatric illness. Finally, we present a model that emphasizes a translational, transdiagnostic approach to understanding externalizing/depression comorbidity. This model should refine ways in which internalizing and externalizing disorders are studied, classified, and treated.

The research of axial corrosion fatigue on 10Ni3CrMoV steel

NASA Astrophysics Data System (ADS)

Xie, Xing; Yi, Hong; Xu, Jian; Xie, Kun

2017-09-01

Fatigue life had been studied with 10CrNi3MoV steel at different load ratios and in different environmental medias. The microstructure and micro-topography had been observed and analyzed by means of SEM, EDS and TEM. Our findings indicated that, the fatigue life of 10Ni3CrMoV steel in seawater was shorter than in air, the difference in longevity was larger with the decreasing of axis stress. Corrosion pits had a great influence on corrosion fatigue life.

Shrinkage vectors of a flowable composite in artificial cavity models with different boundary conditions: Ceramic and Teflon.

PubMed

Kaisarly, Dalia; El Gezawi, Moataz; Xu, Xiaohui; Rösch, Peter; Kunzelmann, Karl-Heinz

2018-01-01

Polymerization shrinkage of dental resin composites leads to stress build-up at the tooth-restoration interface that predisposes the restoration to debonding. In contrast to the heterogeneity of enamel and dentin, this study investigated the effect of boundary conditions in artificial cavity models such as ceramic and Teflon. Ceramic serves as a homogenous substrate that provides optimal bonding conditions, which we presented in the form of etched and silanized ceramic in addition to an etched, silanized and bonded ceramic cavity. In contrast, the Teflon cavity presented a non-adhesive boundary condition that provided an exaggerated condition of poor bonding as in the case of contamination during the application procedure or a poor bonding substrate such as sclerotic or deep dentin. The greatest 3D shrinkage vectors and movement in the axial direction were observed in the ceramic cavity with the bonding agent followed by the silanized ceramic cavity, and smallest shrinkage vectors and axial movements were observed in the Teflon cavity. The shrinkage vectors in the ceramic cavities exhibited downward movement toward the cavity bottom with great downward shrinkage of the free surface. The shrinkage vectors in the Teflon cavity pointed towards the center of the restoration with lateral movement greater at one side denoting the site of first detachment from the cavity walls. These results proved that the boundary conditions, in terms of bonding substrates, significantly influenced the shrinkage direction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Factors Predisposing Drug Abuse.

ERIC Educational Resources Information Center

Cheney, Carl D.; Phelps, Brady J.

The exact nature of the events which may predispose a person to substance abuse is not known. This paper provides a theoretical discussion and review which emphasizes three contexts which have been shown to predispose on individual to drug abuse: (1) prenatal exposure to a given substance; (2) environmental conditions present upon first exposure…

Sildenafil (Viagra) prolongs cardiac repolarization by blocking the rapid component of the delayed rectifier potassium current.

PubMed

Geelen, P; Drolet, B; Rail, J; Bérubé, J; Daleau, P; Rousseau, G; Cardinal, R; O'Hara, G E; Turgeon, J

2000-07-18

BACKGROUND-Several cases of unexpected death have been reported with sildenafil in patients predisposed to ischemic cardiac events. Although acute episodes of ischemia could account for some of these deaths, we hypothesized that sildenafil may have unsuspected electrophysiological effects predisposing some patients to proarrhythmia. METHODS AND RESULTS-Studies were undertaken in 10 isolated guinea pig hearts that demonstrated prolongation of cardiac repolarization in a reverse use-dependent manner by sildenafil 30 mcmol/L. Action potential duration increased 15% from baseline 117+/-3 to 134+/-2 ms with sildenafil during pacing at 250 ms cycle length, whereas a 6% increase from 99+/-2 to 105+/-2 ms was seen with pacing at 150 ms cycle length. Experiments in human ether-a-go-go-related gene (HERG)-transfected HEK293 cells (n=30) demonstrated concentration-dependent block of the rapid component (I(Kr)) of the delayed rectifier potassium current: activating current was 50% decreased at 100 mcmol/L. This effect was confirmed using HERG-transfected Chinese hamster ovary (CHO) cells, which exhibit no endogenous I(K)-like current. CONCLUSIONS-Sildenafil possesses direct cardiac electrophysiological effects similar to class III antiarrhythmic drugs. These effects are observed at concentrations that may be found in conditions of impaired drug elimination such as renal or hepatic insufficiency, during coadministration of another CYP3A substrate/inhibitor, or after drug overdose and offer a new potential explanation for sudden death during sildenafil treatment.

Effect of Macrogeometry on the Surface Topography of Dental Implants.

PubMed

Naves, Marina Melo; Menezes, Helder Henrique Machado; Magalhães, Denildo; Ferreira, Jessica Afonso; Ribeiro, Sara Ferreira; de Mello, José Daniel Biasoli; Costa, Henara Lillian

2015-01-01

Because the microtopography of titanium implants influences the biomaterial-tissue interaction, surface microtexturing treatments are frequently used for dental implants. However, surface treatment alone may not determine the final microtopography of a dental implant, which can also be influenced by the implant macrogeometry. This work analyzed the effects on surface roughness parameters of the same treatment applied by the same manufacturer to implants with differing macro-designs. Three groups of titanium implants with different macro-designs were investigated using laser interferometry and scanning electron microscopy. Relevant surface roughness parameters were calculated for different regions of each implant. Two flat disks (treated and untreated) were also investigated for comparison. The tops of the threads and the nonthreaded regions of all implants had very similar roughness parameters, independent of the geometry of the implant, which were also very similar to those of flat disks treated with the same process. In contrast, the flanks and valleys of the threads presented larger irregularities (Sa) with higher slopes (Sdq) and larger developed surface areas (Sdr) on all implants, particularly for implants with threads with smaller heights. The flanks and valleys displayed stronger textures (Str), particularly on the implants with threads with larger internal angles. Parameters associated with the height of the irregularities (Sa), the slope of the asperities (Sdq), the presence of a surface texture (Str), and the developed surface area of the irregularities (Sdr) were significantly affected by the macrogeometry of the implants. Flat disks subjected to the same surface treatment as dental implants reproduced only the surface topography of the flat regions of the implants.

Interaction of Land Management Intensity and Micro-topography Controls on Geochemistry of Raindrop-Liberated/Mobilized Soil Particles

NASA Astrophysics Data System (ADS)

Hou, T.; Filley, T. R.; Berry, T.; Singh, S.; Hughes, M.; Tong, Y.; Papanicolaou, T.; Wacha, K.; Wilson, C. G.; Chaubey, I.

2017-12-01

The dynamics of raindrop-induced breakdown of soil aggregates, a critical factor in the initial process of surface erosion and lateral redistribution of soil, are strongly tied to land use intensity. What is unclear however is the relative control of rain and mechanical disturbance on the development of landscape-level heterogeneity in surface soil geochemistry. We used artificial rainfall simulated experiments including an aggregate stability test and time course rainfall-erosional test to evaluate the role of management intensity and micro-topography on the geochemistry of raindrop-liberated/mobilized particles from landscapes in southeastern Iowa. Comparing restored prairie, conservation tillage, and conventional tillage sites we found, and with a trend toward increasing tillage intensity, a decrease in aggregate stability and raindrop-liberated particles that were lower in organic carbon, nitrogen, and plant-derived biopolymers, while containing higher proportions of microbially-processed nitrogen than the raindrop stable aggregates. Time evolution of the geochemistry (e.g. elemental, stable isotope, and biopolymer composition) of transported soil particles exhibited distinct patterns based upon both position of the hillslope and oriented soil roughness. Additionally, in the restored prairie, raindrop liberated particles had identical geochemical composition to the raindrop stable aggregates. Our results demonstrate that agricultural sites under intensive tillage have not only a greater potential to liberate and mobilize soil particles during storms, but the mobilized particles will have a distinct chemical character based on tillage intensity, hillslope position and oriented roughness thus lead to a greater potential for landscape level heterogeneity in surface and buried soil chemistry upon mobilization and burial.

Modelling Internal Heterogeneities in Debris-Covered Glaciers: the Potential to Link Morphology and Climate

NASA Astrophysics Data System (ADS)

Stuurman, C. M.; Holt, J.; Levy, J.

2016-12-01

On Earth and Mars, debris-covered glaciers (DCGs) often exhibit arcuate ridges transverse to the flow direction. Additionally, there exists some evidence linking internal structure (which is controlled in part by climate) in DCGs with surface microtopography. A better understanding of the relationship between englacial debris bands, compressional stresses, and debris-covered glacier microtopography will augment understanding of formational environments and mechanisms for terrestrial and martian DCGs. In order to better understand relationships between DCG surface morphology and internal debris bands, we combine field observations with finite-element modeling techniques to relate internal structure of DCGs to their surface morphologies. A geophysical survey including time-domain electromagnetic and ground-penetrating radar techniques of the Galena Creek Rock Glacier, WY was conducted over two field seasons in 2015/2016. Geomorphic analysis by surface observation and photogrammetry, including examination of a cirque-based thermokarst, was used to guide and complement geophysical sounding methods. Very clean ice below a 1 m thick layer of debris was directly observed on the walls of a 40 m diameter thermokarst pond near the accumulation zone. An englacial debris band 0.7 m thick dipping 30o intersected the wall of the pond. Transverse ridges occur at varying ridge-to-ridge wavelengths at different locations on the glacier. The GPR data supports the idea that surface ridges correlate with the intersection of debris layers and the surface. Modelling evidence is consistent with the observation of ridges at debris-layer/surface intersections, with compressional stresses buckling ice up-stream of the debris band.

32 CFR 644.389 - Army military-modified predisposal procedures where E.O. 11954 surveys have been made.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Army military-modified predisposal procedures where E.O. 11954 surveys have been made. 644.389 Section 644.389 National Defense Department of Defense... § 644.389 Army military—modified predisposal procedures where E.O. 11954 surveys have been made. (a) DEs...

The AXAF technology program: The optical flats tests

NASA Technical Reports Server (NTRS)

Williams, A. C.; Harper, J. D.; Reily, J. C.; Weisskopf, M. C.; Wyman, C. L.; Zombeck, M.

1984-01-01

The results of a technology program aimed at determining the limits of surface polishing for reflecting X-ray telescopes is presented. This program is part of the major task of developing the Advanced X-ray Astrophysical Facility (AXAF). By studying the optical properties of state-of-the-art polished flat surfaces, conclusions were drawn as to the potential capability of AXAF. Surface microtopography of the flats as well as their figure are studied by X-ray, visual, and mechanical techniques. These techniques and their results are described. The employed polishing techniques are more than adequate for the specifications of the AXAF mirrors.

SPRUCE S1 Bog Fine-root Production and Standing Crop Assessed With Minirhizotrons in the Southern and Northern Ends of the S1 Bog

DOE Data Explorer

Iversen, C. M. [Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA; Childs, J. [Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA; Norby, R. J. [Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA; Garrett, A. [Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA; Martin, A. [Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA; Spence, J. [Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA; Ontl, T. A. [Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA

2017-01-01

This data set reports fine-root peak growth and standing crop measurements from a forested, ombrotrophic bog as determined using non-destructive minirhizotron technology. Minirhizotron images were collected throughout the growing seasons of 2011 and 2012 at the southern and northern ends of the S1 bog across gradients of tree density in paired hummock and hollow microtopography. The dominant woody species in the bog, and focus of the investigation, were trees Picea mariana and Larix laricina, and ericaceous shrubs Rhododendron groenlandicum and Chamaedaphne calyculata.

An instrument system for long-term sediment transport studies on the continental shelf

USGS Publications Warehouse

Butman, Bradford; Folger, David W.

1979-01-01

A bottom-mounted instrument system has been designed and built to monitor processes of bottom sediment movement on the continental shelf. The system measures bottom current speed and direction, pressure, temperature, and light transmission and photographs the bottom. The system can be deployed for periods of 2–6 months to monitor intermitent processes of sediment movement such as storms and to assess seasonal variability. Deployments of the system on the U.S. east coast continental shelf show sediment resuspension and changes in bottom microtopography due to surface waves, tidal currents, and storms.

Connections between transport in events and transport at landscape-structuring timescales

NASA Astrophysics Data System (ADS)

Harman, C. J.; Lohse, K. A.; Troch, P. A.; Sivapalan, M.

2012-12-01

Complex spatial and temporal variability can arise in the critical zone when feedbacks occur at multiple time scales between transported materials and the landscape and soils through which it is transported. This is clearly illustrated where geomorphic transport processes, soil development, and vegetation interact in semi-arid shrublands. Here we use soil and terrain data and a numerical model of overland flow on semi-arid hillslopes to show that microtopography can generate spatial variations in the dominance of transport processes operating at different timescales, with consequences for the direction of resource redistribution between functional units within these ecosystems. Conceptual and numerical models of the redistribution of mineral, organic and water have mostly been developed on low-gradient alluvial fans and pediments. These have focused on the fluvial transport of resources from the inter-spaces between shrub canopies to the areas below the canopy in those few storm events that generate significant run-off. These processes are believed to produce a mosaic of resource islands in which biota are concentrated. We investigated the spatial distribution of soil properties (including organic matter and soil hydraulic properties), vegetation, and microtopography on two steeper hillslopes of contrasting lithology (one granite, one schist) in the Sonoran desert foothills of the Catalina Mountains. Three hypotheses were developed through iteration between fieldwork and data analysis. These tested whether there were significant differences in soil composition and hydraulic properties below- and between-canopy, whether the surface soil organic matter was directly associated with above-ground biomass, and whether soil organic matter distributions measured along transects below shrubs showed downslope asymmetries indicative of the processes that create them. Data from these sites were used in a numerical model to investigate how these structures could be related to the population of runoff events and processes that generate them. The results suggest that over the long term, slope-dependent transport processes (such as rainsplash, bioturbation and trampling) seem to play an important role in these steeper hillslopes in inverting the flow of resources. Over many storm and inter-storm periods, soil organic matter is transported downslope in plumes extending at least two canopy radii downslope from below woody-shrub canopies into the inter-space. This pattern was particularly evident where microtopography and soil properties create micro-sites protected from fluvial transport. While many of the patterns observed are similar to those from more stable geomorphic surfaces, the results suggest that long-term downslope transport processes in sloping terrain can disrupt the autogenic processes that reinforce the redistribution of resources under shrubs. This result has important implications for our understanding of the relationship between ecosystem function and landscape-scale transport in these environments.

Interplay between field observations and numerical modeling to understand temporal pulsing of tree root throw processes, Canadian Rockies, Canada

NASA Astrophysics Data System (ADS)

Martin, Y. E.; Johnson, E. A.; Chaikina, O.

2013-10-01

During the cycle of forest disturbance, regeneration, and maturity, tree mortality leading to topple is a regular occurrence. When tree topple occurs relatively soon after mortality and if the tree has attained some threshold diameter at breast height (dbh) at the time of death, then notable amounts of soil may be upheaved along with the root wad. This upheaval may result in sediment transfers and soil production. A combination of field evidence and numerical modeling is used herein to gain insights regarding the temporal dynamics of tree topple, associated root throw processes, and pit-mound microtopography. Results from our model of tree population dynamics demonstrate temporal patterns in root throw processes in subalpine forests of the Canadian Rockies, a region in which forests are affected largely by wildfire disturbance. As the forest regenerates after disturbance, the new cohort of trees has to reach a critical dbh before significant root plate upheaval can occur; in the subalpine forests of the Canadian Rockies, this may take up to ~ 102 years. Once trees begin to reach this critical dbh for root plate upheaval, a period of sporadic root throw arises that is caused by mortality of trees during competition. In due course, another wildfire will occur on the landscape and a period of much increased root throw activity then takes place for the next several decades; tree sizes and, therefore, the amount of sediment disturbance will be greater the longer the time period since the previous fire. Results of previous root throw studies covering a number of regional settings are used to guide an exercise in diffusion modeling with the aim of defining a range of reasonable diffusion coefficients for pit-mound degradation; the most appropriate values to fit the field data ranged from 0.01 m2 y- 1 to 0.1 m2 y- 1. A similar exercise is then undertaken that is guided by our field observations in subalpine forests of the Canadian Rockies. For these forests, the most appropriate range of diffusion coefficients is in the range 0.001 m2 y- 1 to 0.01 m2 y- 1. Finally, the model of tree population dynamics is combined with the model of pit-mound degradation to demonstrate the integration of these combined processes on the appearance of pit-mound microtopography and soil bioturbation in subalpine forests of the Canadian Rockies. We conclude that the appearance of notable pit-mound microtopography is limited to very specific time periods and is not visible for much of the time. Most of the hillslope plot is affected by root throw during the 1000-year model run time.

Remote ischemic preconditioning differentially attenuates post-ischemic cardiac arrhythmia in streptozotocin-induced diabetic versus nondiabetic rats.

PubMed

Hu, Zhaoyang; Chen, Mou; Zhang, Ping; Liu, Jin; Abbott, Geoffrey W

2017-04-26

Sudden cardiac death (SCD), a leading cause of global mortality, most commonly arises from a substrate of cardiac ischemia, but requires an additional trigger. Diabetes mellitus (DM) predisposes to SCD even after adjusting for other DM-linked cardiovascular pathology such as coronary artery disease. We previously showed that remote liver ischemia preconditioning (RLIPC) is highly protective against cardiac ischemia reperfusion injury (IRI) linked ventricular arrhythmias and myocardial infarction, via induction of the cardioprotective RISK pathway, and specifically, inhibitory phosphorylation of GSK-3β (Ser 9). We evaluated the impact of acute streptozotocin-induced DM on coronary artery ligation IRI-linked ventricular arrhythmogenesis and RLIPC therapy in rats. Post-IRI arrhythmia induction was similar in nondiabetic and DM rats, but, unexpectedly, DM rats exhibited lower incidence of SCD during reperfusion (41 vs. 100%), suggesting uncontrolled hyperglycemia does not acutely predispose to SCD. RLIPC was highly effective in both nondiabetic and DM rats at reducing incidence and duration of, and increasing latency to, all classes of ventricular tachyarrhythmias. In contrast, atrioventricular block (AVB) was highly responsive to RLIPC in nondiabetic rats (incidence reduced from 72 to 18%) but unresponsive in DM rats. RISK pathway induction was similar in nondiabetic and DM rats, thus not explaining the DM-specific resistance of AVB to therapy. Our findings uncover important acute DM-specific differences in responsiveness to remote preconditioning for ventricular tachyarrhythmias versus AVB, which may have clinical significance given that AVB is a malignant arrhythmia twofold more common in human diabetics than nondiabetics, and correlated to plasma glucose levels >10 mmol/L.

Need, Enabling, Predisposing, and Behavioral Determinants of Access to Preventative Care in Argentina: Analysis of the National Survey of Risk Factors

PubMed Central

Jahangir, Eiman; Irazola, Vilma; Rubinstein, Adolfo

2012-01-01

Introduction Health care utilization is an important step to disease management, providing opportunities for prevention and treatment. Anderson’s Health Behavior Model has defined utilization by need, predisposing, and enabling determinants. We hypothesize that need, predisposing, and enabling, highlighting behavioral factors are associated with utilization in Argentina. Methods We performed a logistic regression analysis of the 2005 and 2009 Argentinean Survey of Risk Factors, a cohort of 41,392 and 34,732 individuals, to explore the association between need, enabling, predisposing, and behavioral factors to blood pressure measurement in the last year. Results In the 2005 cohort, blood pressure measurement was associated with perception of health, insurance coverage, basic needs met, and income. Additionally, female sex, civil state, household type, older age groups, education, and alcohol use were associated with utilization. The 2009 cohort showed similar associations with only minor differences between the models. Conclusions We explored the association between utilization of clinical preventive services with need, enabling, predisposing, and behavioral factors. While predisposing and need determinants are associated with utilization, enabling factors such as insurance coverage provides an area for public intervention. These are important findings where policies should be focused to improve utilization of preventive services in Argentina. PMID:22984608

Sleep and dreaming are for important matters

PubMed Central

Perogamvros, L.; Dang-Vu, T. T.; Desseilles, M.; Schwartz, S.

2013-01-01

Recent studies in sleep and dreaming have described an activation of emotional and reward systems, as well as the processing of internal information during these states. Specifically, increased activity in the amygdala and across mesolimbic dopaminergic regions during REM sleep is likely to promote the consolidation of memory traces with high emotional/motivational value. Moreover, coordinated hippocampal-striatal replay during NREM sleep may contribute to the selective strengthening of memories for important events. In this review, we suggest that, via the activation of emotional/motivational circuits, sleep and dreaming may offer a neurobehavioral substrate for the offline reprocessing of emotions, associative learning, and exploratory behaviors, resulting in improved memory organization, waking emotion regulation, social skills, and creativity. Dysregulation of such motivational/emotional processes due to sleep disturbances (e.g., insomnia, sleep deprivation) would predispose to reward-related disorders, such as mood disorders, increased risk-taking and compulsive behaviors, and may have major health implications, especially in vulnerable populations. PMID:23898315

Microbial diversity in hummock and hollow soils of three wetlands on the Qinghai-Tibetan Plateau revealed by 16S rRNA pyrosequencing.

PubMed

Deng, Yongcui; Cui, Xiaoyong; Hernández, Marcela; Dumont, Marc G

2014-01-01

The wetlands of the Qinghai-Tibetan Plateau are believed to play an important role in global nutrient cycling, but the composition and diversity of microorganisms in this ecosystem are poorly characterized. An understanding of the effects of geography and microtopography on microbial populations will provide clues to the underlying mechanisms that structure microbial communities. In this study, we used pyrosequencing-based analysis of 16S rRNA gene sequences to assess and compare the composition of soil microbial communities present in hummock and hollow soils from three wetlands (Dangxiong, Hongyuan and Maduo) on the Qinghai-Tibetan Plateau, the world's highest plateau. A total of 36 bacterial phyla were detected. Proteobacteria (34.5% average relative abundance), Actinobacteria (17.3%) and Bacteroidetes (11%) had the highest relative abundances across all sites. Chloroflexi, Acidobacteria, Verrucomicrobia, Firmicutes, and Planctomycetes were also relatively abundant (1-10%). In addition, archaeal sequences belonging to Euryarchaea, Crenarchaea and Thaumarchaea were detected. Alphaproteobacteria sequences, especially of the order Rhodospirillales, were significantly more abundant in Maduo than Hongyuan and Dangxiong wetlands. Compared with Hongyuan soils, Dangxiong and Maduo had significantly higher relative abundances of Gammaproteobacteria sequences (mainly order Xanthomonadales). Hongyuan wetland had a relatively high abundance of methanogens (mainly genera Methanobacterium, Methanosarcina and Methanosaeta) and methanotrophs (mainly Methylocystis) compared with the other two wetlands. Principal coordinate analysis (PCoA) indicated that the microbial community structure differed between locations and microtopographies and canonical correspondence analysis indicated an association between microbial community structure and soil properties or geography. These insights into the microbial community structure and the main controlling factors in wetlands of the Qinghai-Tibetan Plateau provide a valuable background for further studies on biogeochemical processes in this distinct ecosystem.

Microbial Diversity in Hummock and Hollow Soils of Three Wetlands on the Qinghai-Tibetan Plateau Revealed by 16S rRNA Pyrosequencing

PubMed Central

Deng, Yongcui; Cui, Xiaoyong; Hernández, Marcela; Dumont, Marc G.

2014-01-01

The wetlands of the Qinghai-Tibetan Plateau are believed to play an important role in global nutrient cycling, but the composition and diversity of microorganisms in this ecosystem are poorly characterized. An understanding of the effects of geography and microtopography on microbial populations will provide clues to the underlying mechanisms that structure microbial communities. In this study, we used pyrosequencing-based analysis of 16S rRNA gene sequences to assess and compare the composition of soil microbial communities present in hummock and hollow soils from three wetlands (Dangxiong, Hongyuan and Maduo) on the Qinghai-Tibetan Plateau, the world’s highest plateau. A total of 36 bacterial phyla were detected. Proteobacteria (34.5% average relative abundance), Actinobacteria (17.3%) and Bacteroidetes (11%) had the highest relative abundances across all sites. Chloroflexi, Acidobacteria, Verrucomicrobia, Firmicutes, and Planctomycetes were also relatively abundant (1–10%). In addition, archaeal sequences belonging to Euryarchaea, Crenarchaea and Thaumarchaea were detected. Alphaproteobacteria sequences, especially of the order Rhodospirillales, were significantly more abundant in Maduo than Hongyuan and Dangxiong wetlands. Compared with Hongyuan soils, Dangxiong and Maduo had significantly higher relative abundances of Gammaproteobacteria sequences (mainly order Xanthomonadales). Hongyuan wetland had a relatively high abundance of methanogens (mainly genera Methanobacterium, Methanosarcina and Methanosaeta) and methanotrophs (mainly Methylocystis) compared with the other two wetlands. Principal coordinate analysis (PCoA) indicated that the microbial community structure differed between locations and microtopographies and canonical correspondence analysis indicated an association between microbial community structure and soil properties or geography. These insights into the microbial community structure and the main controlling factors in wetlands of the Qinghai-Tibetan Plateau provide a valuable background for further studies on biogeochemical processes in this distinct ecosystem. PMID:25078273

Combined use of LiDAR data and multispectral earth observation imagery for wetland habitat mapping

NASA Astrophysics Data System (ADS)

Rapinel, Sébastien; Hubert-Moy, Laurence; Clément, Bernard

2015-05-01

Although wetlands play a key role in controlling flooding and nonpoint source pollution, sequestering carbon and providing an abundance of ecological services, the inventory and characterization of wetland habitats are most often limited to small areas. This explains why the understanding of their ecological functioning is still insufficient for a reliable functional assessment on areas larger than a few hectares. While LiDAR data and multispectral Earth Observation (EO) images are often used separately to map wetland habitats, their combined use is currently being assessed for different habitat types. The aim of this study is to evaluate the combination of multispectral and multiseasonal imagery and LiDAR data to precisely map the distribution of wetland habitats. The image classification was performed combining an object-based approach and decision-tree modeling. Four multispectral images with high (SPOT-5) and very high spatial resolution (Quickbird, KOMPSAT-2, aerial photographs) were classified separately. Another classification was then applied integrating summer and winter multispectral image data and three layers derived from LiDAR data: vegetation height, microtopography and intensity return. The comparison of classification results shows that some habitats are better identified on the winter image and others on the summer image (overall accuracies = 58.5 and 57.6%). They also point out that classification accuracy is highly improved (overall accuracy = 86.5%) when combining LiDAR data and multispectral images. Moreover, this study highlights the advantage of integrating vegetation height, microtopography and intensity parameters in the classification process. This article demonstrates that information provided by the synergetic use of multispectral images and LiDAR data can help in wetland functional assessment

Response of deep soil moisture to land use and afforestation in the semi-arid Loess Plateau, China

NASA Astrophysics Data System (ADS)

Yang, Lei; Wei, Wei; Chen, Liding; Mo, Baoru

2012-12-01

SummarySoil moisture is an effective water source for plant growth in the semi-arid Loess Plateau of China. Characterizing the response of deep soil moisture to land use and afforestation is important for the sustainability of vegetation restoration in this region. In this paper, the dynamics of soil moisture were quantified to evaluate the effect of land use on soil moisture at a depth of 2 m. Specifically, the gravimetric soil moisture content was measured in the soil layer between 0 and 8 m for five land use types in the Longtan catchment of the western Loess Plateau. The land use types included traditional farmland, native grassland, and lands converted from traditional farmland (pasture grassland, shrubland and forestland). Results indicate that the deep soil moisture content decreased more than 35% after land use conversion, and a soil moisture deficit appeared in all types of land with introduced vegetation. The introduced vegetation decreased the soil moisture content to levels lower than the reference value representing no human impact in the entire 0-8 m soil profile. No significant differences appeared between different land use types and introduced vegetation covers, especially in deeper soil layers, regardless of which plant species were introduced. High planting density was found to be the main reason for the severe deficit of soil moisture. Landscape management activities such as tillage activities, micro-topography reconstruction, and fallowed farmland affected soil moisture in both shallow and deep soil layers. Tillage and micro-topography reconstruction can be used as effective countermeasures to reduce the soil moisture deficit due to their ability to increase soil moisture content. For sustainable vegetation restoration in a vulnerable semi-arid region, the plant density should be optimized with local soil moisture conditions and appropriate landscape management practices.

Spatial and Temporal Variation in Primary Productivity (NDVI) of Coastal Alaskan Tundra: Decreased Vegetation Growth Following Earlier Snowmelt

NASA Technical Reports Server (NTRS)

Gamon, John A.; Huemmrich, K. Fred; Stone, Robert S.; Tweedie, Craig E.

2015-01-01

In the Arctic, earlier snowmelt and longer growing seasons due to warming have been hypothesized to increase vegetation productivity. Using the Normalized Difference Vegetation Index (NDVI) from both field and satellite measurements as an indicator of vegetation phenology and productivity, we monitored spatial and temporal patterns of vegetation growth for a coastal wet sedge tundra site near Barrow, Alaska over three growing seasons (2000-2002). Contrary to expectation, earlier snowmelt did not lead to increased productivity. Instead, productivity was associated primarily with precipitation and soil moisture, and secondarily with growing degree days, which, during this period, led to reduced growth in years with earlier snowmelt. Additional moisture effects on productivity and species distribution, operating over a longer time scale, were evident in spatial NDVI patterns associated with microtopography. Lower, wetter regions dominated by graminoids were more productive than higher, drier locations having a higher percentage of lichens and mosses, despite the earlier snowmelt at the more elevated sites. These results call into question the oft-stated hypothesis that earlier arctic growing seasons will lead to greater vegetation productivity. Rather, they agree with an emerging body of evidence from recent field studies indicating that early-season, local environmental conditions, notably moisture and temperature, are primary factors determining arctic vegetation productivity. For this coastal arctic site, early growing season conditions are strongly influenced by microtopography, hydrology, and regional sea ice dynamics, and may not be easily predicted from snowmelt date or seasonal average air temperatures alone. Our comparison of field to satellite NDVI also highlights the value of in-situ monitoring of actual vegetation responses using field optical sampling to obtain detailed information on surface conditions not possible from satellite observations alone.

On the Representation of Subgrid Microtopography Effects in Process-based Hydrologic Models

NASA Astrophysics Data System (ADS)

Jan, A.; Painter, S. L.; Coon, E. T.

2017-12-01

Increased availability of high-resolution digital elevation are enabling process-based hydrologic modeling on finer and finer scales. However, spatial variability in surface elevation (microtopography) exists below the scale of a typical hyper-resolution grid cell and has the potential to play a significant role in water retention, runoff, and surface/subsurface interactions. Though the concept of microtopographic features (depressions, obstructions) and the associated implications on flow and discharge are well established, representing those effects in watershed-scale integrated surface/subsurface hydrology models remains a challenge. Using the complex and coupled hydrologic environment of the Arctic polygonal tundra as an example, we study the effects of submeter topography and present a subgrid model parameterized by small-scale spatial heterogeneities for use in hyper-resolution models with polygons at a scale of 15-20 meters forming the surface cells. The subgrid model alters the flow and storage terms in the diffusion wave equation for surface flow. We compare our results against sub-meter scale simulations (acts as a benchmark for our simulations) and hyper-resolution models without the subgrid representation. The initiation of runoff in the fine-scale simulations is delayed and the recession curve is slowed relative to simulated runoff using the hyper-resolution model with no subgrid representation. Our subgrid modeling approach improves the representation of runoff and water retention relative to models that ignore subgrid topography. We evaluate different strategies for parameterizing subgrid model and present a classification-based method to efficiently move forward to larger landscapes. This work was supported by the Interoperable Design of Extreme-scale Application Software (IDEAS) project and the Next-Generation Ecosystem Experiments-Arctic (NGEE Arctic) project. NGEE-Arctic is supported by the Office of Biological and Environmental Research in the DOE Office of Science.

Near-Surface Profiles of Water Stable Isotope Components and Indicated Transitional History of Ice-Wedge Polygons Near Barrow

NASA Astrophysics Data System (ADS)

Iwahana, G.; Wilson, C.; Newman, B. D.; Heikoop, J. M.; Busey, R.

2017-12-01

Wetlands associated with ice-wedge polygons are commonly distributed across the Arctic Coastal Plain of northern Alaska, a region underlain by continuous permafrost. Micro-topography of the ice-wedge polygons controls local hydrology, and the micro-topography could be altered due to factors such like surface vegetation, wetness, freeze-thaw cycles, and permafrost degradation/aggradation under climate change. Understanding status of the wetlands in the near future is important because it determines biogeochemical cycle, which drives release of greenhouse gases from the ground. However, transitional regime of the ice-wedge polygons under the changing climate is not fully understood. In this study, we analyzed geochemistry of water extracted from frozen soil cores sampled down to about 1m depth in 2014 March at NGEE-Arctic sites in the Barrow Environmental Observatory. The cores were sampled from troughs/rims/centers of five different low-centered or flat-centered polygons. The frozen cores are divided into 5-10cm cores for each location, thawed in sealed plastic bags, and then extracted water was stored in vials. Comparison between the profiles of geochemistry indicated connection of soil water in the active layer at different location in a polygon, while it revealed that distinctly different water has been stored in permafrost layer at troughs/rims/centers of some polygons. Profiles of volumetric water content (VWC) showed clear signals of freeze-up desiccation in the middle of saturated active layers as low VWC anomalies at most sampling points. Water in the active layer and near-surface permafrost was classified into four categories: ice wedge / fresh meteoric / transitional / highly fractionated water. The overall results suggested prolonged separation of water in the active layer at the center of low-centered polygons without lateral connection in water path in the past.

MBG-Modified β-TCP Scaffold Promotes Mesenchymal Stem Cells Adhesion and Osteogenic Differentiation via a FAK/MAPK Signaling Pathway.

PubMed

Liu, Yutong; Ma, Yifan; Zhang, Jing; Xie, Qing; Wang, Zi; Yu, Shuang; Yuan, Yuan; Liu, Changsheng

2017-09-13

The β-TCP scaffold has been widely used as a bone graft substitute, but the traditional PMMA molding method-induced undesirable mechanical strength and poor interconnectivity still have not been addressed until now. In this study, a MBG-based PU foam templating method was developed to fabricate β-TCP scaffolds with desirable microtopography. The MBG gel, as both binder and modifier, prepared by a modified sol-gel method with controlled viscosity is incorporated with β-TCP powder and thereafter is impregnated into PU foam. The resultant hybrid scaffolds exhibited interconnected macropores (200-500 μm) and distinctive micropores (0.2-1.5 μm), especially for the TCP/25MBG (with 25 wt % content MBG). As expected, the compression strength of β-TCP/MBG composite scaffolds was enhanced with increasing MBG content, and TCP/50MBG (with 50 wt % content MBG) exhibited almost 100-fold enhancement compared to the pure β-TCP. Intriguingly, the cell affinity and osteogenic capacity of rBMSCs were also dramatically improved the best on TCP/25MBG. Further investigation found that the subtle, grainy-like microtopography, not the chemical composition, of the TCP/25MBG favored the adsorption of Fn and expression of integrin α5β1 and further facilitated FA formation and the expression of p-FAK, following activation of the MAPK/ERK signaling pathway and ultimately upregulated expression of osteogenic genes. Further in vivo experiments confirmed the promoted osteogenesis of TCP/25MBG in vivo. The results suggest that such a novel MBG-based PU foam templating method offers new guidance to construct hierarchically porous scaffolds, and the prepared MBG-modified β-TCP scaffold will have great potential for future use in bone tissue regeneration.

Mechanisms That Generate Resource Pulses in a Fluctuating Wetland

PubMed Central

Botson, Bryan A.; Gawlik, Dale E.; Trexler, Joel C.

2016-01-01

Animals living in patchy environments may depend on resource pulses to meet the high energetic demands of breeding. We developed two primary a priori hypotheses to examine relationships between three categories of wading bird prey biomass and covariates hypothesized to affect the concentration of aquatic fauna, a pulsed resource for breeding wading bird populations during the dry season. The fish concentration hypothesis proposed that local-scale processes concentrate wet-season fish biomass into patches in the dry season, whereas the fish production hypothesis states that the amount of dry-season fish biomass reflects fish biomass production during the preceding wet season. We sampled prey in drying pools at 405 sites throughout the Florida Everglades between December and May from 2006–2010 to test these hypotheses. The models that explained variation in dry-season fish biomass included water-level recession rate, wet-season biomass, microtopography, submerged vegetation, and the interaction between wet-season biomass and recession rate. Crayfish (Procambarus spp.) biomass was positively associated with wet-season crayfish biomass, moderate water depth, dense submerged aquatic vegetation, thin flocculent layer and a short interval of time since the last dry-down. Grass shrimp (Palaemonetes paludosus) biomass increased with increasing rates of water level recession, supporting our impression that shrimp, like fish, form seasonal concentrations. Strong support for wet-season fish and crayfish biomass in the top models confirmed the importance of wet-season standing stock to concentrations of fish and crayfish the following dry season. Additionally, the importance of recession rate and microtopography showed that local scale abiotic factors transformed fish production into the high quality foraging patches on which apex predators depended. PMID:27448023

Controls of Parent Material and Topography on Soil Carbon Storage in the Critical Zone

NASA Astrophysics Data System (ADS)

Patton, N. R.; Seyfried, M. S.; Lohse, K. A.; Link, T. E.

2014-12-01

Semi-arid environments make up a large percentage of the world's terrestrial ecosystems, and climate is a major factor influencing soil carbon storage and release. However, the roles of local controls such as parent material, aspect and microtopography have received less attention and are important for consideration in soil carbon modeling. The purpose of this study is to understand the role that parent material, aspect and micro-topography play in storage and release of soil carbon along an elevation gradient in a semi-arid climate. Johnston Draw (JD) is a first order watershed within the Reynolds Creek Critical Zone Observatory in southwestern Idaho with underlining late cretaceous, granitic Idaho batholith bedrock. Upper Sheep Creek (USC) is a first order watershed consisting of basalt. Both watersheds were chosen for this project due to similar size, aspect, elevation, vegetation and for the contrast in parent material. Two transects, totaling approximately nine soil pits, were excavated on both the north and south facing slopes of each watershed running parallel to the water channel. Soil carbon was generally higher in basalt compared to the granite parent material in pits with similar aspect, elevation and vegetation. Preliminary data using soil organic matter (SOM) as a proxy for organic carbon (OC) and soil water dynamics showed that percent OC declines markedly with elevation in JD and soil depth at lower elevations and is more homogenous throughout the profile moving up elevation (1646 meters 4.3-9.7%; 1707 meters 6.87-3.83%). Similarly, aspect controls patterns of SOM at depth more strongly at lower elevations. Findings from our study suggest that parent material and topography may play as important roles in semi-arid ecosystems as climate factors in controlling soil carbon storage.

Isotopic and Geochemical Fingerprinting of a Polygonal Arctic Ecosystem

NASA Astrophysics Data System (ADS)

Throckmorton, H.; Heikoop, J. M.; Newman, B. D.; Wilson, C. J.; Wullschleger, S. D.

2015-12-01

Arctic tundra contain large C stocks and may be an important source of CO2 and CH4 over the next century due to a rapidly changing climate, degrading permafrost, and redistribution of water across high latitude landscapes. This presentation synthesizes geochemical and isotopic data and examines vertical and lateral factors and processes critical to predicting the C, N, and water balance of tundra ecosystems. Stable water isotope analyses (delta 2H and delta 18O) indicate that summer rain is the dominant source for active layer groundwater, with melting seasonal ice contributing to deeper pore waters in late summer. Microtopography and water table effects on geochemistry were apparent from a comprehensive spatial examination of active layer biogeochemistry, showing a number of significant differences in the concentrations of cations and anions for high- vs. low-centered polygons, microtopographic features (polygonal centers vs. troughs), and with depth. Results have implications for future nutrient availability with projected permafrost degradation and landscape evolution, suggesting greater availability of limiting nutrients (sulfate, phosphate, and nitrate) where polygons undergo a shift from low- to high-centered. Nitrate isotopes (delta 15N and delta 18O) indicated a predominantly microbial source for nitrate in high centered polygons active layers. However, atmospheric nitrate was preserved in permafrost, and may serve as a potential indicator of permafrost degradation. Additionally, results suggest that older, deeper C sources may be promoting a shift in methanogenic pathway, from predominantly acetoclastic to hydrogenotrophic. This mechanistic shift is attributed to the source and quality of available organic substrate. Overall, results showed substantial lateral and vertical variability in biogeochemical, biogeophysical, and hydrological processes across microtopographic- to landscape scales that needs to be accounted for in fine and intermediate scale models.

New insights into the effects of biomaterial chemistry and topography on the morphology of kidney epithelial cells.

PubMed

Hulshof, Frits; Schophuizen, Carolien; Mihajlovic, Milos; van Blitterswijk, Clemens; Masereeuw, Rosalinde; de Boer, Jan; Stamatialis, Dimitrios

2018-02-01

Increasing incidence of renal pathology in the western world calls for innovative research for the development of cell-based therapies such as a bioartificial kidney (BAK) device. To fulfil the multitude of kidney functions, the core component of the BAK is a living membrane consisting of a tight kidney cell monolayer with preserved functional organic ion transporters cultured on a polymeric membrane surface. This membrane, on one side, is in contact with blood and therefore should have excellent blood compatibility, whereas the other side should facilitate functional monolayer formation. This work investigated the effect of membrane chemistry and surface topography on kidney epithelial cells to improve the formation of a functional monolayer. To achieve this, microtopographies were fabricated with high resolution and reproducibility on polystyrene films and on polyethersulfone-polyvinyl pyrrolidone (PES-PVP) porous membranes. A conditionally immortalized proximal tubule epithelial cell line (ciPTEC) was cultured on both, and subsequently, the cell morphology and monolayer formation were assessed. Our results showed that L-dopamine coating of the PES-PVP was sufficient to support ciPTEC monolayer formation. The polystyrene topographies with large features were able to align the cells in various patterns without significantly disruption of monolayer formation; however, the PES-PVP topographies with large features disrupted the monolayer. In contrast, the PES-PVP membranes with small features and with large spacing supported well the ciPTEC monolayer formation. In addition, the topographical PES-PVP membranes were compatible as a substrate membrane to measure organic cation transporter activity in Transwell® systems. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Detecting disease-predisposing variants: the haplotype method.

PubMed Central

Valdes, A M; Thomson, G

1997-01-01

For many HLA-associated diseases, multiple alleles-- and, in some cases, multiple loci--have been suggested as the causative agents. The haplotype method for identifying disease-predisposing amino acids in a genetic region is a stratification analysis. We show that, for each haplotype combination containing all the amino acid sites involved in the disease process, the relative frequencies of amino acid variants at sites not involved in disease but in linkage disequilibrium with the disease-predisposing sites are expected to be the same in patients and controls. The haplotype method is robust to mode of inheritance and penetrance of the disease and can be used to determine unequivocally whether all amino acid sites involved in the disease have not been identified. Using a resampling technique, we developed a statistical test that takes account of the nonindependence of the sites sampled. Further, when multiple sites in the genetic region are involved in disease, the test statistic gives a closer fit to the null expectation when some--compared with none--of the true predisposing factors are included in the haplotype analysis. Although the haplotype method cannot distinguish between very highly correlated sites in one population, ethnic comparisons may help identify the true predisposing factors. The haplotype method was applied to insulin-dependent diabetes mellitus (IDDM) HLA class II DQA1-DQB1 data from Caucasian, African, and Japanese populations. Our results indicate that the combination DQA1#52 (Arg predisposing) DQB1#57 (Asp protective), which has been proposed as an important IDDM agent, does not include all the predisposing elements. With rheumatoid arthritis HLA class II DRB1 data, the results were consistent with the shared-epitope hypothesis. PMID:9042931

Effect of load ratio and saltwater corrosive environment on the initiation life of fatigue of 10Ni5CrMoV steel

NASA Astrophysics Data System (ADS)

Xie, Xing; Yi, Hong; Xu, Jian; Gen, Liming; Chen, Luyun

2017-09-01

Fatigue initiation life has been studied with 10CrNi5MoV steel for use in ocean engineering at different load ratios and in different environmental media. The microstructure and micro-topography have been observed and analyzed by means of SEM, EDS and EBSD. Our findings indicate that, the initiation life of 10Ni5CrMoV steel in seawater is shorter than that in air, and the difference in longevity is larger with the increasing of load ratio. Corrosion pits had a great influence on initial corrosion fatigue life.

Optical microtopographic inspection of asphalt pavement surfaces

NASA Astrophysics Data System (ADS)

Costa, Manuel F. M.; Freitas, E. F.; Torres, H.; Cerezo, V.

2017-08-01

Microtopographic and rugometric characterization of surfaces is routinely and effectively performed non-invasively by a number of different optical methods. Rough surfaces are also inspected using optical profilometers and microtopographer. The characterization of road asphalt pavement surfaces produced in different ways and compositions is fundamental for economical and safety reasons. Having complex structures, including topographically with different ranges of form error and roughness, the inspection of asphalt pavement surfaces is difficult to perform non-invasively. In this communication we will report on the optical non-contact rugometric characterization of the surface of different types of road pavements performed at the Microtopography Laboratory of the Physics Department of the University of Minho.

Remote sensing sensors and applications in environmental resources mapping and modeling

USGS Publications Warehouse

Melesse, Assefa M.; Weng, Qihao; Thenkabail, Prasad S.; Senay, Gabriel B.

2007-01-01

The history of remote sensing and development of different sensors for environmental and natural resources mapping and data acquisition is reviewed and reported. Application examples in urban studies, hydrological modeling such as land-cover and floodplain mapping, fractional vegetation cover and impervious surface area mapping, surface energy flux and micro-topography correlation studies is discussed. The review also discusses the use of remotely sensed-based rainfall and potential evapotranspiration for estimating crop water requirement satisfaction index and hence provides early warning information for growers. The review is not an exhaustive application of the remote sensing techniques rather a summary of some important applications in environmental studies and modeling.

SPRUCE S1 Bog Sphagnum CO2 Flux Measurements and Partitioning into Re and GPP

DOE Data Explorer

Walker, A. P. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Carter, K. R. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Hanson, P. J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Nettles, W. R. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Philips, J. R. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Sebestyen, S. D. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Weston, D. J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.

2015-06-01

This data set provides (1) the results of in-situ Sphagnum-peat hourly net ecosystem exchange (NEE) measured using a LICOR 8100 gas exchange system and (2) the component fluxes -- gross primary production (GPP) and ecosystem respiration (Re), derived using empirical regressions.NEE measurements were made from 6 June to 6 November 2014 and 20 March to 10 May 2015. Three 8100 chambers per dominant species (S. magellanicum or S. fallax) were placed in the S1 Bog in relatively open ground where there was no obvious hummock-hollow microtopography. The 8100 chambers were not located in the SPRUCE experimental enclosures.

The use of UAVs for monitoring land degradation

NASA Astrophysics Data System (ADS)

Themistocleous, Kyriacos

2017-10-01

Land degradation is one of the causes of desertification of drylands in the Mediterranean. UAVs can be used to monitor and document the various variables that cause desertification in drylands, including overgrazing, aridity, vegetation loss, etc. This paper examines the use of UAVs and accompanying sensors to monitor overgrazing, vegetation stress and aridity in the study area. UAV images can be used to generate digital elevation models (DEMs) to examine the changes in microtopography as well as ortho-photos were used to detect changes in vegetation patterns. The combined data of the digital elevation models and the orthophotos can be used to identify the mechanisms for desertification in the study area.

Role of Substance P in the Regulation of Glucose Metabolism via Insulin Signaling-Associated Pathways

PubMed Central

Bakirtzi, Kyriaki; Kokkotou, Efi; Stavrakis, Dimitris; Margolis, Kara Gross; Thomou, Thomas; Giorgadze, Nino; Kirkland, James L.

2011-01-01

Substance P (SP), encoded by the tachykinin 1 (Tac1) gene, is the most potent tachykinin ligand for the high-affinity neurokinin-1 receptor (NK-1R). We previously reported that NK-1R-deficient mice show less weight gain and reduced circulating levels of leptin and insulin in response to a high-fat diet (HFD) and demonstrated the presence of functional NK-1R in isolated human preadipocytes. Here we assessed the effects of SP on weight gain in response to HFD and determined glucose metabolism in Tac1-deficient (Tac1−/−) mice. The effect of SP on the expression of molecules that may predispose to reduced glucose uptake was also determined in isolated human mesenteric, omental, and sc preadipocytes. We show that although weight accumulation in response to HFD was similar between Tac1−/− mice and wild-type littermates, Tac1−/− mice demonstrated lower glucose and leptin and increased adiponectin blood levels and showed improved responses to insulin challenge after HFD. SP stimulated phosphorylation of c-Jun N-terminal kinase, protein kinase Cθ, mammalian target of rapamycin, and inhibitory serine insulin receptor substrate-1 phosphorylation in human preadipocytes in vitro. Preincubation of human mesenteric preadipocytes with the protein kinase Cθ pseudosubstrate inhibitor reduced insulin receptor substrate 1 phosphorylation in response to SP. Lastly, SP also induced insulin receptor substrate-1 phosphorylation in mature human sc adipocytes. Our results demonstrate an important role for SP in adipose tissue responses and obesity-associated pathologies. These novel SP effects on molecules that enhance insulin resistance at the adipocyte level may reflect an important role for this peptide in the pathophysiology of type 2 diabetes. PMID:22009727

Role of substance P in the regulation of glucose metabolism via insulin signaling-associated pathways.

PubMed

Karagiannides, Iordanes; Bakirtzi, Kyriaki; Kokkotou, Efi; Stavrakis, Dimitris; Margolis, Kara Gross; Thomou, Thomas; Giorgadze, Nino; Kirkland, James L; Pothoulakis, Charalabos

2011-12-01

Substance P (SP), encoded by the tachykinin 1 (Tac1) gene, is the most potent tachykinin ligand for the high-affinity neurokinin-1 receptor (NK-1R). We previously reported that NK-1R-deficient mice show less weight gain and reduced circulating levels of leptin and insulin in response to a high-fat diet (HFD) and demonstrated the presence of functional NK-1R in isolated human preadipocytes. Here we assessed the effects of SP on weight gain in response to HFD and determined glucose metabolism in Tac1-deficient (Tac1(-/-)) mice. The effect of SP on the expression of molecules that may predispose to reduced glucose uptake was also determined in isolated human mesenteric, omental, and sc preadipocytes. We show that although weight accumulation in response to HFD was similar between Tac1(-/-) mice and wild-type littermates, Tac1(-/-) mice demonstrated lower glucose and leptin and increased adiponectin blood levels and showed improved responses to insulin challenge after HFD. SP stimulated phosphorylation of c-Jun N-terminal kinase, protein kinase C, mammalian target of rapamycin, and inhibitory serine insulin receptor substrate-1 phosphorylation in human preadipocytes in vitro. Preincubation of human mesenteric preadipocytes with the protein kinase C pseudosubstrate inhibitor reduced insulin receptor substrate 1 phosphorylation in response to SP. Lastly, SP also induced insulin receptor substrate-1 phosphorylation in mature human sc adipocytes. Our results demonstrate an important role for SP in adipose tissue responses and obesity-associated pathologies. These novel SP effects on molecules that enhance insulin resistance at the adipocyte level may reflect an important role for this peptide in the pathophysiology of type 2 diabetes.

Quantification of Greenhouse Gas Emissions from the Predisposal Stage of Municipal Solid Waste Management.

PubMed

Zhou, Chuanbin; Jiang, Daqian; Zhao, Zhilan

2017-01-03

Municipal solid waste (MSW) disposal represents one of the largest sources of anthropogenic greenhouse gas (GHG) emissions. However, the biogenic GHG emissions in the predisposal stage of MSW management (i.e., the time from waste being dropped off in community or household garbage bins to being transported to disposal sites) are excluded from the IPCC inventory methodology and rarely discussed in academic literature. Herein, we quantify the effluxes of carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O) from garbage bins in five communities along the urban-rural gradient in Beijing in four seasons. We find that the annual average CO 2 , CH 4 , and N 2 O effluxes in the predisposal stage were (1.6 ± 0.9)10 3 , 0.049 ± 0.016, and 0.94 ± 0.54 mg kg -1 h -1 (dry matter basis) and had significant seasonal differences (24- to 159-fold) that were strongly correlated with temperature. According to our estimate, the N 2 O emission in the MSW predisposal stage amounts to 20% of that in the disposal stage in Beijing, making the predisposal stage a nontrivial source of waste-induced N 2 O emissions. Furthermore, the CO 2 and CH 4 emissions in the MSW predisposal account for 5% (maximum 10% in summer) of the total carbon contents in a Beijing's household food waste stream, which has significance in the assessment of MSW-related renewable energy potential and urban carbon cycles.

High-throughput behavioral phenotyping of drug and alcohol susceptibility traits in the expanded panel of BXD recombinant inbred strains

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

Philip, Vivek M; Ansah, T; Blaha, C,

Genetic reference populations, particularly the BXD recombinant inbred strains, are a valuable resource for the discovery of the bio-molecular substrates and genetic drivers responsible for trait variation and co- ariation. This approach can be profitably applied in the analysis of susceptibility and mechanisms of drug and alcohol use disorders for which many predisposing behaviors may predict occurrence and manifestation of increased preference for these substances. Many of these traits are modeled by common mouse behavioral assays, facilitating the detection of patterns and sources of genetic co-regulation of predisposing phenotypes and substance consumption. Members of the Tennessee Mouse Genome Consortium havemore » obtained behavioral phenotype data from 260 measures related to multiple behavioral assays across several domains: self-administration, response to, and withdrawal from cocaine, MDMA, morphine and alcohol; novelty seeking; behavioral despair and related neurological phenomena; pain sensitivity; stress sensitivity; anxiety; hyperactivity; and sleep/wake cycles. All traits have been measured in both sexes and the recently expanded panel of 69 additional BXD recombinant inbred strains (N=69). Sex differences and heritability estimates were obtained for each trait, and a comparison of early (N = 32) and recent BXD RI lines was performed. Primary data is publicly available for heritability, sex difference and genetic analyses using www.GeneNetwork.org. These analyses include QTL detection and genetic analysis of gene expression. Stored results from these analyses are available at http://ontologicaldiscovery.org for comparison to other genomic analysis results. Together with the results of related studies, these data form a public resource for integrative systems genetic analysis of neurobehavioral traits.« less

Contribution of early environmental stress to alcoholism vulnerability.

PubMed

Campbell, Joannalee C; Szumlinski, Karen K; Kippin, Tod E

2009-11-01

The most problematic aspects of alcohol abuse disorder are excessive alcohol consumption and the inability to refrain from alcohol consumption during attempted abstinence. The root causes that predispose certain individuals to these problems are poorly understood but are believed to be produced by a combination of genetic and environmental factors. Early environmental trauma alters neurodevelopmental trajectories that can predispose an individual to a number of neuropsychiatric disorders, including substance abuse. Prenatal stress (PNS) is a well-established protocol that produces perturbations in nervous system development, resulting in behavioral alterations that include hyperresponsiveness to stress, novelty, and psychomotor stimulant drugs (e.g., cocaine, amphetamine). Moreover, PNS animals exhibit enduring alterations in basal and cocaine-induced changes in dopamine and glutamate transmission within limbic structures, which exhibit pathology in drug addiction and alcoholism, suggesting that these alterations may contribute to an increased propensity to self-administer large amounts of drugs of abuse or to relapse after periods of drug withdrawal. Given that cocaine and alcohol have actions on common limbic neural substrates (albeit by different mechanisms), we hypothesized that PNS would elevate the motivation for, and consumption of, alcohol. Accordingly, we have found that male C57BL/6J mice subject to PNS exhibit higher operant responding and consume more alcohol during alcohol reinforcement as adults. Alterations in glutamate and dopamine neurotransmission within the forebrain structures appear to contribute to the PNS-induced predisposition to high alcohol intake and are induced by excessive alcohol intake. Accordingly, we are exploring the interactions between neurochemical changes produced by PNS and changes induced by consumption of alcohol in adulthood to model the biological bases of high vulnerability to alcohol abuse.

Contribution of early environmental stress to alcoholism vulnerability

PubMed Central

Campbell, Joannalee C.; Szumlinski, Karen K.; Kippin, Tod E.

2011-01-01

The most problematic aspects of alcohol abuse disorder are excessive alcohol consumption and the inability to refrain from alcohol consumption during attempted abstinence. The root causes that predispose certain individuals to these problems are poorly understood but are believed to be produced by a combination of genetic and environmental factors. Early environmental trauma alters neurodevelopmental trajectories that can predispose an individual to a number of neuropsychiatric disorders, including substance abuse. Prenatal stress (PNS) is a well-established protocol that produces perturbations in nervous system development, resulting in behavioral alterations that include hyperresponsiveness to stress, novelty, and psychomotor stimulant drugs (e.g., cocaine, amphetamine). Moreover, PNS animals exhibit enduring alterations in basal and cocaine-induced changes in dopamine and glutamate transmission within limbic structures, which exhibit pathology in drug addiction and alcoholism, suggesting that these alterations may contribute to an increased propensity to self-administer large amounts of drugs of abuse or to relapse after periods of drug withdrawal. Given that cocaine and alcohol have actions on common limbic neural substrates (albeit by different mechanisms), we hypothesized that PNS would elevate the motivation for, and consumption of, alcohol. Accordingly, we have found that male C57BL/6J mice subject to PNS exhibit higher operant responding and consume more alcohol during alcohol reinforcement as adults. Alterations in glutamate and dopamine neurotransmission within the forebrain structures appear to contribute to the PNS-induced predisposition to high alcohol intake and are induced by excessive alcohol intake. Accordingly, we are exploring the interactions between neurochemical changes produced by PNS and changes induced by consumption of alcohol in adulthood to model the biological bases of high vulnerability to alcohol abuse. PMID:19913199

Clinical Characteristics of 17 Patients with Moraxella Keratitis.

PubMed

Tobimatsu, Yui; Inada, Noriko; Shoji, Jun; Yamagami, Satoru

2018-01-08

To retrospectively investigate the clinical characteristics of Moraxella keratitis. We reviewed the medical records of 17 patients with Moraxella keratitis. Onset age, sex, predisposing factors, initial clinical presentations, culture and antimicrobial susceptibility testing, and management and outcome of medical treatment were investigated. Moraxella keratitis was more common in patients older than 40 years of age, and its representative initial presentation was a round-shaped ulcer with endothelial plaque (70.6%) and hypopyon (58.8%). Local predisposing factors were significantly more frequent than systemic predisposing factors (P < 0.005). Isolated strains of Moraxella (M. catarrhalis, M. osloensis, and other Moraxella spp.) were sensitive to all antibiotics tested except ampicillin. The common disease contraction period was <2 weeks. Moraxella keratitis (including the first report of M. osloensis keratitis) had local predisposing factors, high sensitivity to antibiotics, and a tendency to recover within 2 weeks.

Remote Sensing Sensors and Applications in Environmental Resources Mapping and Modelling

PubMed Central

Melesse, Assefa M.; Weng, Qihao; S.Thenkabail, Prasad; Senay, Gabriel B.

2007-01-01

The history of remote sensing and development of different sensors for environmental and natural resources mapping and data acquisition is reviewed and reported. Application examples in urban studies, hydrological modeling such as land-cover and floodplain mapping, fractional vegetation cover and impervious surface area mapping, surface energy flux and micro-topography correlation studies is discussed. The review also discusses the use of remotely sensed-based rainfall and potential evapotranspiration for estimating crop water requirement satisfaction index and hence provides early warning information for growers. The review is not an exhaustive application of the remote sensing techniques rather a summary of some important applications in environmental studies and modeling. PMID:28903290

Predisposing factors for atrial fibrillation in the elderly

PubMed Central

Wasmer, Kristina; Eckardt, Lars; Breithardt, Günter

2017-01-01

Atrial fibrillation (AF) in the elderly occurs as a consequence of cardiovascular aging and an age related increase of comorbidity. Several predisposing factors for AF have been identified for the overall AF population. Most of them, cardiovascular disease in particular, play a role in younger and older patients. The longer time period during which these risk factors can cause structural changes that ultimately lead to AF may, at least in part, explain the association between age and AF. In addition, less well defined age-related changes in cellular electrophysiologic properties and structure predispose to AF in the elderly. PMID:28592961

Correlates of specific childhood feeding problems.

PubMed

Field, D; Garland, M; Williams, K

2003-01-01

The correlates of specific childhood feeding problems are described to further examine possible predisposing factors for feeding problems. We report our experience with 349 participants evaluated by an interdisciplinary feeding team. A review of records was conducted and each participant was identified as having one or more of five functionally defined feeding problems: food refusal, food selectivity by type, food selectivity by texture, oral motor delays, or dysphagia. The prevalence of predisposing factors for these feeding problems was examined. Predisposing factors included developmental disabilities, gastrointestinal problems, cardiopulmonary problems, neurological problems, renal disease and anatomical anomalies. The frequencies of predisposing factors varied by feeding problem. Differences were found in the prevalence of the five feeding problems among children with three different developmental disabilities: autism, Down syndrome and cerebral palsy. Gastro-oesophageal reflux was the most prevalent condition found among all children in the sample and was the factor most often associated with food refusal. Neurological conditions and anatomical anomalies were highly associated with skill deficits, such as oral motor delays and dysphagia. Specific medical conditions and developmental disabilities are often associated with certain feeding problems. Information concerning predisposing factors of feeding problems can help providers employ appropriate primary, secondary and tertiary prevention measures to decrease the frequency or severity of some feeding problems.

Moraxella keratitis: predisposing factors and clinical review of 95 cases

PubMed Central

Das, S; Constantinou, M; Daniell, M; Taylor, H R

2006-01-01

Aim To analyse the clinical presentation, identify predisposing risk factors and evaluate the outcome of treatment of Moraxella keratitis. Methods A retrospective analysis was carried out of culture‐proved cases of Moraxella keratitis from hospital records during a 10‐year period (from December 1995 to November 2005) at the Corneal Unit of the Royal Victorian Eye and Ear Hospital, Melbourne, Australia. Results 95 episodes of Moraxella keratitis were identified in 92 patients. 3 (3.2%) patients had recurrent keratitis. The mean age of the patients was 70 (range 17–93) years. Multiple predisposing factors were identified in 23 (24%) eyes, including corneal graft (n = 15), previous herpes keratitis (n = 15) and eye lid diseases (n = 15). Adjunctive procedures were carried out in 42 eyes. These included botulinum toxin injection (n = 17), tarsorraphy (n = 12), penetrating keratoplasty (n = 8), enucleation (n = 3), tissue adhesive and bandage contact lens (n = 4), and conjunctival flap (n = 5). Polymicrobial infection was present in 17 eyes. Final visual acuity was counting finger or less in 25 (26%) eyes. Conclusions Local ocular predisposing factors play a major role in Moraxella keratitis. This infection has a poor visual outcome attributable to both the nature of the infection and the predisposing factors. PMID:16825274

Youth at Risk: In Search of a Definition.

ERIC Educational Resources Information Center

Tidwell, Romeria; Garrett, Susan Corona

1994-01-01

Reviews the definitions of the term "youth at risk" and their perspectives on predisposing conditions. Discusses implications for counseling. Asserts that the sound diagnosis and treatment of adolescents' problems involves careful identification of predisposing conditions and negative outcomes. Includes 16 citations. (Author/CRR)

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

Kumar, Jitendra; Collier, Nathan; Bisht, Gautam

Vast carbon stocks stored in permafrost soils of Arctic tundra are under risk of release to the atmosphere under warming climate scenarios. Ice-wedge polygons in the low-gradient polygonal tundra create a complex mosaic of microtopographic features. This microtopography plays a critical role in regulating the fine-scale variability in thermal and hydrological regimes in the polygonal tundra landscape underlain by continuous permafrost. Modeling of thermal regimes of this sensitive ecosystem is essential for understanding the landscape behavior under the current as well as changing climate. Here, we present an end-to-end effort for high-resolution numerical modeling of thermal hydrology at real-world fieldmore » sites, utilizing the best available data to characterize and parameterize the models. We also develop approaches to model the thermal hydrology of polygonal tundra and apply them at four study sites near Barrow, Alaska, spanning across low to transitional to high-centered polygons, representing a broad polygonal tundra landscape. A multiphase subsurface thermal hydrology model (PFLOTRAN) was developed and applied to study the thermal regimes at four sites. Using a high-resolution lidar digital elevation model (DEM), microtopographic features of the landscape were characterized and represented in the high-resolution model mesh. The best available soil data from field observations and literature were utilized to represent the complex heterogeneous subsurface in the numerical model. Simulation results demonstrate the ability of the developed modeling approach to capture – without recourse to model calibration – several aspects of the complex thermal regimes across the sites, and provide insights into the critical role of polygonal tundra microtopography in regulating the thermal dynamics of the carbon-rich permafrost soils. Moreover, areas of significant disagreement between model results and observations highlight the importance of field-based observations of soil thermal and hydraulic properties for modeling-based studies of permafrost thermal dynamics, and provide motivation and guidance for future observations that will help address model and data gaps affecting our current understanding of the system.« less

Representing northern peatland microtopography and hydrology within the Community Land Model

DOE PAGES

Shi, Xiaoying; Thornton, Peter E.; Ricciuto, Daniel M.; ...

2015-11-12

Predictive understanding of northern peatland hydrology is a necessary precursor to understanding the fate of massive carbon stores in these systems under the influence of present and future climate change. Current models have begun to address microtopographic controls on peatland hydrology, but none have included a prognostic calculation of peatland water table depth for a vegetated wetland, independent of prescribed regional water tables. We introduce here a new configuration of the Community Land Model (CLM) which includes a fully prognostic water table calculation for a vegetated peatland. Our structural and process changes to CLM focus on modifications needed to representmore » the hydrologic cycle of bogs environment with perched water tables, as well as distinct hydrologic dynamics and vegetation communities of the raised hummock and sunken hollow microtopography characteristic of peatland bogs. The modified model was parameterized and independently evaluated against observations from an ombrotrophic raised-dome bog in northern Minnesota (S1-Bog), the site for the Spruce and Peatland Responses Under Climatic and Environmental Change experiment (SPRUCE). Simulated water table levels compared well with site-level observations. The new model predicts hydrologic changes in response to planned warming at the SPRUCE site. At present, standing water is commonly observed in bog hollows after large rainfall events during the growing season, but simulations suggest a sharp decrease in water table levels due to increased evapotranspiration under the most extreme warming level, nearly eliminating the occurrence of standing water in the growing season. Simulated soil energy balance was strongly influenced by reduced winter snowpack under warming simulations, with the warming influence on soil temperature partly offset by the loss of insulating snowpack in early and late winter. Furthermore, the new model provides improved predictive capacity for seasonal hydrological dynamics in northern peatlands, and provides a useful foundation for investigation of northern peatland carbon exchange.« less

Representing northern peatland microtopography and hydrology within the Community Land Model

DOE PAGES

Shi, X.; Thornton, P. E.; Ricciuto, D. M.; ...

2015-02-20

Predictive understanding of northern peatland hydrology is a necessary precursor to understanding the fate of massive carbon stores in these systems under the influence of present and future climate change. Current models have begun to address microtopographic controls on peatland hydrology, but none have included a prognostic calculation of peatland water table depth for a vegetated wetland, independent of prescribed regional water tables. We introduce here a new configuration of the Community Land Model (CLM) which includes a fully prognostic water table calculation for a vegetated peatland. Our structural and process changes to CLM focus on modifications needed to representmore » the hydrologic cycle of bogs environment with perched water tables, as well as distinct hydrologic dynamics and vegetation communities of the raised hummock and sunken hollow microtopography characteristic of peatland bogs. The modified model was parameterized and independently evaluated against observations from an ombrotrophic raised-dome bog in northern Minnesota (S1-Bog), the site for the Spruce and Peatland Responses Under Climatic and Environmental Change experiment (SPRUCE). Simulated water table levels compared well with site-level observations. The new model predicts significant hydrologic changes in response to planned warming at the SPRUCE site. At present, standing water is commonly observed in bog hollows after large rainfall events during the growing season, but simulations suggest a sharp decrease in water table levels due to increased evapotranspiration under the most extreme warming level, nearly eliminating the occurrence of standing water in the growing season. Simulated soil energy balance was strongly influenced by reduced winter snowpack under warming simulations, with the warming influence on soil temperature partly offset by the loss of insulating snowpack in early and late winter. The new model provides improved predictive capacity for seasonal hydrological dynamics in northern peatlands, and provides a useful foundation for investigation of northern peatland carbon exchange.« less

Selective etching of injection molded zirconia-toughened alumina: Towards osseointegrated and antibacterial ceramic implants.

PubMed

Flamant, Quentin; Caravaca, Carlos; Meille, Sylvain; Gremillard, Laurent; Chevalier, Jérôme; Biotteau-Deheuvels, Katia; Kuntz, Meinhard; Chandrawati, Rona; Herrmann, Inge K; Spicer, Christopher D; Stevens, Molly M; Anglada, Marc

2016-12-01

Due to their outstanding mechanical properties and excellent biocompatibility, zirconia-toughened alumina (ZTA) ceramics have become the gold standard in orthopedics for the fabrication of ceramic bearing components over the last decade. However, ZTA is bioinert, which hampers its implantation in direct contact with bone. Furthermore, periprosthetic joint infections are now the leading cause of failure for joint arthroplasty prostheses. To address both issues, an improved surface design is required: a controlled micro- and nano-roughness can promote osseointegration and limit bacterial adhesion whereas surface porosity allows loading and delivery of antibacterial compounds. In this work, we developed an integrated strategy aiming to provide both osseointegrative and antibacterial properties to ZTA surfaces. The micro-topography was controlled by injection molding. Meanwhile a novel process involving the selective dissolution of zirconia (selective etching) was used to produce nano-roughness and interconnected nanoporosity. Potential utilization of the porosity for loading and delivery of antibiotic molecules was demonstrated, and the impact of selective etching on mechanical properties and hydrothermal stability was shown to be limited. The combination of injection molding and selective etching thus appears promising for fabricating a new generation of ZTA components implantable in direct contact with bone. Zirconia-toughened alumina (ZTA) is the current gold standard for the fabrication of orthopedic ceramic components. In the present work, we propose an innovative strategy to provide both osseointegrative and antibacterial properties to ZTA surfaces: we demonstrate that injection molding allows a flexible design of surface micro-topography and can be combined with selective etching, a novel process that induces nano-roughness and surface interconnected porosity without the need for coating, avoiding reliability issues. These surface modifications have the potential to improve osseointegration. Furthermore, our results show that the porosity can be used for drug delivery and suggest that the etched surface could reduce bacterial adhesion. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

COMPARATIVE EVALUATION OF RISK FACTORS FOR CARDIOVASCULAR DISEASE (CVD) IN GENETICALLY PREDISPOSED RATS

EPA Science Inventory

Rodent CVD models are increasingly used for understanding individual differences in susceptibility to environmental stressors such as air pollution. We characterized pathologies and a number of known human risk factors of CVD in genetically predisposed, male young adult Spontaneo...

Homozygous parent affected sib pair method for detecting disease predisposing variants: application to insulin dependent diabetes mellitus.

PubMed

Robinson, W P; Barbosa, J; Rich, S S; Thomson, G

1993-01-01

For complex genetic diseases involving incomplete penetrance, genetic heterogeneity, and multiple disease genes, it is often difficult to determine the molecular variant(s) responsible for the disease pathogenesis. Linkage and association studies may help identify genetic regions and molecular variants suspected of being directly responsible for disease predisposition or protection, but, especially for complex diseases, they are less useful for determining when a predisposing molecular variant has been identified. In this paper, we expand upon the simple concept that if a genetic factor predisposing to disease has been fully identified, then a parent homozygous for this factor should transmit either of his/her copies at random to any affected children. Closely linked markers are used to determine identity by descent values in affected sib pairs from a parent homozygous for a putative disease predisposing factor. The expected deviation of haplotype sharing from 50%, when not all haplotypes carrying this factor are in fact equally predisposing, has been algebraically determined for a single locus general disease model. Equations to determine expected sharing for multiple disease alleles or multiple disease locus models have been formulated. The recessive case is in practice limiting and therefore can be used to estimate the maximum proportion of putative susceptibility haplotypes which are in fact predisposing to disease when the mode of inheritance of a disease is unknown. This method has been applied to 27 DR3/DR3 parents and 50 DR4/DR4 parents who have at least 2 children affected with insulin dependent diabetes mellitus (IDDM). The transmission of both DR3 and DR4 haplotypes is statistically different from 50% (P < 0.05 and P < 0.001, respectively). An upper estimate for the proportion of DR3 haplotypes associated with a high IDDM susceptibility is 49%, and for DR4 haplotypes 38%. Our results show that the joint presence of non-Asp at DQ beta position 57 and Arg at DQ alpha position 52, which has been proposed as a strong IDDM predisposing factor, is insufficient to explain the HLA component of IDDM predisposition.

Predisposing, Precipitating, Perpetuating, Professional Help, and Prevention Factors of Eating Disorders.

ERIC Educational Resources Information Center

Moriarty, Dick; Chanko, Cathy

This report describes an eating disorder as a multi-dimensional physiological, psychological, social, and cultural illness. A chart describing the typical anorexic and bulimic is included which has on its horizontal axis the predisposing, precipitating, perpetuating, professional help, and prevention factors of anorexia nervosa and bulimia. On its…

Multiple Drug-Use Patterns Among a Group of High School Students: Regular Users vs. Nonusers of Specific Drug Types

ERIC Educational Resources Information Center

Seffrin, John R.; Seehafer, Roger W.

1976-01-01

Although no cause-effect relationship can be shown, regular drug use seems to predispose one to further drug experimentation and use, while non-use of a particular drug seems to predispose one to non-use of other drugs. (Author/MB)

Maternal air pollution exposure induces fetal neuroinflammation and predisposes offspring to obesity in aduthood in a sex-specific manner

EPA Science Inventory

Emerging evidence suggests environmental chemical exposures during critical windows of development may contribute to the escalating prevalence of obesity. We tested the hypothesis that prenatal air pollution exposure would predispose the offspring to weight gain in adulthood. Pre...

Rubinstein-Taybi syndrome predisposing to non-WNT, non-SHH, group 3 medulloblastoma.

PubMed

Bourdeaut, Franck; Miquel, Catherine; Richer, Wilfrid; Grill, Jacques; Zerah, Michel; Grison, Camille; Pierron, Gaelle; Amiel, Jeanne; Krucker, Clementine; Radvanyi, Francois; Brugieres, Laurence; Delattre, Olivier

2014-02-01

Medulloblastomas (MB) are classified in four subgroups: the well defined WNT and Sonic Hedgehog (SHH) subgroups, and the less defined groups 3 and 4. They occasionally occur in the context of a cancer predisposition syndrome. While germline APC mutations predispose to WNT MB, germline mutations in SUFU, PTCH1, and TP53 predispose to SHH tumors. We report on a child with a Rubinstein-Taybi syndrome (RTS) due to a germline deletion in CREBBP, who developed a MB. Biological profilings demonstrate that this tumor belongs to the group 3. RTS may therefore be the first predisposition syndrome identified for non-WNT/non-SHH MB. © 2013 Wiley Periodicals, Inc.

Screening for Alcohol Risk in Predominantly Hispanic Youths: Positive Rates and Behavioral Consequences

ERIC Educational Resources Information Center

Tomaka, Joe; Salaiz, Rebekah A.; Morales-Monks, Stormy; Thompson, Sharon; McKinnon, Sarah; O'Rourke, Kathleen

2012-01-01

The present study examined relationships between CAGE alcohol risk scores and predisposing factors for alcohol use, current alcohol use, and behavioral consequences in a large sample of secondary students. Students completed the CAGE, measures of demographics, potential predisposing factors, and consequences of alcohol use. More than 18% of…

Correlates of Home Health Care Services Use among the Elderly.

ERIC Educational Resources Information Center

Starrett, Richard A.; And Others

The use of health and social services is influenced by economic, community, geographic, organizational, societal, and environmental factors. A study was conducted to examine predisposing, enabling, and need-for-care factors related to the use of home health care services by a stratified random sample of 400 older adults. Predisposing factors…

Examining the Diet of Post-Migrant Hispanic Males Using the Precede-Proceed Model: Predisposing, Reinforcing, and Enabling Dietary Factors

ERIC Educational Resources Information Center

Castellanos, Diana Cuy; Downey, Laura; Graham-Kresge, Susan; Yadrick, Kathleen; Zoellner, Jamie; Connell, Carol L.

2013-01-01

Objective: To examine socio-environmental, behavioral, and predisposing, reinforcing, and enabling (PRE) factors contributing to post-migration dietary behavior change among a sample of traditional Hispanic males. Design: In this descriptive study, semistructured interviews, a group interview, and photovoice, followed by group interviews, were…

Contextual and individual determinants of periodontal disease: Multilevel analysis based on Andersen's model.

PubMed

Valente, Maria I B; Vettore, Mario V

2018-04-01

To investigate the relationship of contextual and individual factors with periodontal disease in dentate adults and older people using the Andersen's behavioural model. Secondary individual data from 6011 adults and 2369 older people from the Brazilian Oral Health Survey (2010) were combined with contextual data for 27 cities. Attachment loss (AL) categories for each sextant were coded and summed to obtain the periodontal disease measure. The association of predisposing, enabling and need characteristics at city and individual level with periodontal disease was assessed using an adapted version of the Andersen's behavioural model. Multilevel Poisson regression was used to estimate rate ratios (RR) and 95% CIs. Periodontal disease was associated with contextual predisposing (RR 0.93; 95% CI = 0.87-0.99) and enabling factors (RR 0.99; 95% CI = 0.98-0.99) in adults. Contextual predisposing was also associated with periodontal disease in older people (RR 0.82; 95% CI = 0.73-0.92). Individual predisposing (age, sex and schooling) and need characteristics (perceived treatment need) were common predictors of periodontal disease in adults and older people. Periodontal disease was also associated with behaviours in the latter age group. Contextual predisposing factors and individual characteristics influenced periodontal disease experience in adults and older people. Contextual enabling factors were also meaningful determinants of periodontal disease in the former age group. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Psychosocial correlates of healthful diets: baseline results from the Working Well Study.

PubMed

Kristal, A R; Patterson, R E; Glanz, K; Heimendinger, J; Hebert, J R; Feng, Z; Probart, C

1995-05-01

This report examines psychosocial factors related to selection of healthful diets. Understanding why people select healthful diets can lead to rational design and evaluation of nutrition intervention programs. Data are from 16,287 respondents to the baseline survey for the Working Well Trial, a randomized, controlled trial of worksite-based health promotion. The psychosocial constructs we measured were predisposing factors (beliefs, perceived benefits, and motivation; 5 items, Cronbach's alpha = 0.65) and enabling factors (barriers, norms, and social support; 6 items, Cronbach's alpha = 0.57). The healthful diet outcomes were intakes of fat, fiber, and servings of fruits and vegetables (from a food frequency questionnaire) and intention and self-efficacy to decrease fat and increase fruits and vegetables. Based on a 5-point scale (1 = low to 5 = high), the mean predisposing factor scale score was much higher than the enabling factor scale score (3.77 vs 2.50, P < 0.001). Comparing respondents in the highest category of the predisposing scale to those in the lowest, mean percentage of energy from fat was 22.4% lower (-9 percentage points), fiber was 85.2% higher (+4.6 g/1,000 kcal), and fruits and vegetables were 100% higher (+1.6 servings/day) (all trends, P < 0.001). Associations were similar, but much weaker, for the enabling scale. Multiple regression models, which included covariates related to diet and the predisposing and enabling scales, explained a total of between 13 and 26% of the variance in diet and intention to change diet. After control for covariates, the predisposing scale remained a significant and strong predictor of diet and intention to change diet but the enabling scale explained small and nonsignificant amounts of variance. Predisposing factors are strong predictors of current diet and intention to change diet. Final results from the Working Well Trial will provide more information on whether enabling factors can be enhanced by intervention and whether these changes result in healthier eating patterns.

Predisposing factors and susceptibility assessment for deep-seated gravitational slope deformations (DSGSDs): a case study (NW Alps, Italy)

NASA Astrophysics Data System (ADS)

Lo Russo, S.; Forno, M. G.; Taddia, G.; Gnavi, L.

2012-04-01

KEY WORDS: Deep-seated gravitational slope deformation (DSGSD); Risk; Hazard; Susceptibility; Piemonte; Italy Deep-seated gravitational slope deformations (DSGSDs) and "sackung" deformations are complex processes of gravitational movement that involve large volumes of rock, often several tens of meters thick and several kilometers long. The development and characteristics of deep-seated gravitational slope deformations (DSGSDs) have not yet been fully explained. If unrecognized, these deformations can cause serious damage to rigid infrastructures such as dams, tunnels, and water conduits. Early identification of these phenomena and their predisposing factors through detailed geological and geomorphological surveys is therefore necessary for the correct location, construction, and expansion of fixed infrastructures. The hazard evaluation component of landslide risk assessment combines measures of susceptibility and triggering variables. This approach may not be applicable to DSGSDs, given the difficulty of quantifying the probability of occurrence within a specified period of time without well-defined DSGSD triggering factors. Evaluation of DSGSDs should thus be restricted to the assessment of susceptibility. Zones of DSGSD susceptibility can be identified through geological and geomorphological analysis, by overlapping maps of the four main predisposing factors (lithology, neotectonic activity, relief energy, morphological deglaciation evidence). The attribution of a susceptibility level to a certain zone cannot replace a hazard evaluation, but it can be a good index of the potential presence of a DSGSD. A DSGSD is most likely in a territory characterized by the worst combination of predisposing factors (high susceptibility): poor rock mechanics, intense neotectonic activity (high seismicity, active faults), high energy relief, and evidence of past glacialism. The probability of a DSGSD correspondingly decreases if one or more of the predisposing factors are absent (low susceptibility). A case study of two DSGSDs located in the Rodoretto Valley (northwestern Alps, Italy) has been examined. After detailed field survey provided morphological identification of these features, the authors conducted a back-analysis to assess the susceptibility of the entire valley. Each main predisposing factor has been independently mapped, and the level of susceptibility to DSGSD has been identified through geographic information system (GIS) overlapping of the four maps. The results confirm the combined presence of four main predisposing factors for the examined DGSDs, indicating high susceptibility.

Mechanisms of atrial tachyarrhythmias associated with coronary artery occlusion in a chronic canine model.

PubMed

Nishida, Kunihiro; Qi, Xiao Yan; Wakili, Reza; Comtois, Philippe; Chartier, Denis; Harada, Masahide; Iwasaki, Yu-ki; Romeo, Philippe; Maguy, Ange; Dobrev, Dobromir; Michael, Georghia; Talajic, Mario; Nattel, Stanley

2011-01-18

Coronary artery disease predisposes to atrial fibrillation (AF), but the effects of chronic atrial ischemia/infarction on AF-related substrates are unknown. Regional right atrial myocardial infarction (MI) was created in 40 dogs by ligating an artery that supplies the right atrial free wall and not the ventricles; 35 sham dogs with the same artery isolated but not ligated were controls. Dogs were observed 8 days after MI and subjected to open-chest study, in vitro optical mapping, and/or cell isolation for patch-clamp and Ca(2+) imaging on day 8. Holter ECGs showed more spontaneous atrial ectopy in MI dogs (eg, 662±281 on day 7 versus 34±25 ectopic complexes per day at baseline; 52±21 versus 1±1 atrial tachycardia episodes per day). Triggered activity was increased in MI border zone cells, which had faster decay of caffeine-evoked Ca(2+) transients and enhanced (by ≈73%) Na(+)-Ca(2+) exchange current. Spontaneous Ca(2+) sparks (confocal microscopy) occurred under β-adrenergic stimulation in more MI dog cells (66±9%) than in control cells (29±4%; P<0.01). Burst pacing induced long-lasting AF in MI dogs (1146±259 versus 30±14 seconds in shams). Increased border zone conduction heterogeneity was confirmed by both bipolar electrode mapping in vivo and optical mapping. Optical mapping demonstrated stable border zone reentry in all 9 MI preparations but in none of 6 shams. Border zone tissue showed increased fibrous tissue content. Chronic atrial ischemia/infarction creates substrates for both spontaneous ectopy (Ca(2+)-release events, increased Na(+)-Ca(2+) exchange current) and sustained reentry (conduction abnormalities that anchor reentry). Thus, chronic atrial infarction in dogs promotes both AF triggers and the substrate for AF maintenance. These results provide novel insights into potential AF mechanisms in patients with coronary artery disease.

Effect of phase composition of calcium silicate phosphate component on properties of brushite based composite cements

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

Sopcak, T., E-mail: tsopcak@imr.saske.sk; Medvecky, L.; Giretova, M.

The composite cement mixtures were prepared by mixing brushite (B) with, the amorphous hydrated calcium silicate phosphate (CSPH) or annealed calcium silicate phosphate (CSP composed of Si-saturated hydroxyapatite, wollastonite and silica) phases and water as liquid component. The contents of the silicate-phosphate phase in composites were 10.30 and 50 wt%. The significant effect of both the Ca/P ratio and different solubility of calcium silicate phosphate component in starting cement systems on setting time and phase composition of the final composite cements was demonstrated. The compressive strength of the set cements increased with the filler addition and the highest value (~more » 48 MPa) exhibited the 50CSP/B cement composite. The final setting times of the composite cements decreased with the CSPH addition from about 25 to 17 min in 50CSHP/B and setting time of CSP/B composites was around 30 min. The higher content of silica in cements caused the precipitation of fine hydroxyapatite particles in the form of nanoneedles or thin plates perpendicularly oriented to sample surface. The analysis of in vitro cement cytotoxicity demonstrated the strong reduction in cytotoxicity of 10CSPH/B composite with time of cultivation (a low cytotoxicity after 9 days of culture) contrary to cements with higher calcium silicate-phosphate content. These results were attributed to the different surface topography of composite substrates and possible stimulation of cell proliferation by the slow continuously release of ions from 10CSPH/B cement. - Highlights: • Ca/P ratio and solubility of calcium silicate-phosphate components affect the self-setting properties of cements. • Strong relationship between the composite in vitro cytotoxicity and surface microtopography was demonstrated. • Plate-like morphology of coarser particles allowed cells to better adhere and proliferate as compared with nanoneedles.« less

Canine intervertebral disc disease: a review of etiologic and predisposing factors.

PubMed

Verheijen, J; Bouw, J

1982-01-01

In this report the literature on etiologic and predisposing factors of disc disease in the dog is reviewed and discussed. Hypochondroplasia is considered to be important in the etiology of disc disease. After some consideration on nomenclature and morphology, the genetic background of hypochondroplasia is described. The histochemical morphological and developmental similarities and differences between and within various dog breeds are discussed. Macroscopically visible features that predispose to disc disease are outlined. The biomechanical bow-string model of the vertebral column is reviewed. In the discussion the various literature data are interrelated to show how disc disease might be reduced by breeding measures without implicating the breed characteristics. Literature recommendations to help the individual dog are included.

Overnutrition and maternal obesity in sheep pregnancy alter the JNK-IRS-1 signaling cascades and cardiac function in the fetal heart

PubMed Central

Wang, Jingying; Ma, Heng; Tong, Chao; Zhang, Hanying; Lawlis, Gavin B.; Li, Yuanda; Zang, Mengwei; Ren, Jun; Nijland, Mark J.; Ford, Stephen P.; Nathanielsz, Peter W.; Li, Ji

2010-01-01

Maternal obesity in pregnancy predisposes offspring to insulin resistance and associated cardiovascular disease. Here, we used a well-established sheep model to investigate the effects of maternal obesity on cardiac functions. Multiparous ewes were assigned to a control (CON) diet [100% of National Research Council (NRC) recommendations] or an obesogenic (OB) diet (150% of NRC recommendations) from 60 d before conception to necropsy on d 135 of pregnancy. Fetal blood glucose and insulin were increased (P<0.01, n=8) in OB (35.09±2.03 mg/dl and 3.40±1.43 μU/ml, respectively) vs. CON ewes (23.80±1.38 mg/dl and 0.769±0.256 μU/ml). Phosphorylation of AMP-activated protein kinase (AMPK), a cardioprotective signaling pathway, was reduced (P<0.05), while the stress signaling pathway, p38 MAPK, was up-regulated (P<0.05) in OB maternal and fetal hearts. Phosphorylation of c-Jun N-terminal kinase (JNK) and insulin receptor substrate-1 (IRS-1) at Ser-307 were increased (P<0.05) in OB fetal heart associated with lower downstream PI3K-Akt activity (P<0.05), indicating impaired cardiac insulin signaling. Although OB fetal hearts exhibited a normal contractile function vs. CON fetal hearts during basal perfusion, they developed an impaired heart-rate-left-ventricular-developed pressure product in response to high workload stress. Taken together, fetuses of OB mothers demonstrate alterations in cardiac PI3K-Akt, AMPK, and JNK-IRS-1 signaling pathways that would predispose them to insulin resistance and cardiac dysfunction.—Wang, J., Ma, H., Tong, C., Zhang, H., Lawlis, G. B., Li, Y., Zang, M., Ren, J., Nijland, M. J., Ford, S. P., Nathanielsz, P. W., Li, J. Overnutrition and maternal obesity in sheep pregnancy alter the JNK-IRS-1 signaling cascades and cardiac function in the fetal heart. PMID:20110268

Age, Predisposing Diseases, and Ultrasonographic Findings in Determining Clinical Outcome of Acute Acalculous Inflammatory Gallbladder Diseases in Children

PubMed Central

2016-01-01

We evaluated clinical factors such as age, gender, predisposing diseases and ultrasonographic findings that determine clinical outcome of acute acalculous inflammatory gallbladder diseases in children. The patients were divided into the four age groups. From March 2004 through February 2014, clinical data from 131 children diagnosed as acute acalculous inflammatory gallbladder disease by ultrasonography were retrospectively reviewed. Systemic infectious diseases were the most common etiology of acute inflammatory gallbladder disease in children and were identified in 50 patients (38.2%). Kawasaki disease was the most common predisposing disease (28 patients, 21.4%). The incidence was highest in infancy and lowest in adolescence. The age groups were associated with different predisposing diseases; noninfectious systemic disease was the most common etiology in infancy and early childhood, whereas systemic infectious disease was the most common in middle childhood and adolescence (P = 0.001). Gallbladder wall thickening was more commonly found in malignancy (100%) and systemic infection (94.0%) (P = 0.002), whereas gallbladder distension was more frequent in noninfectious systemic diseases (60%) (P = 0.000). Ascites seen on ultrasonography was associated with a worse clinical course compared with no ascites (77.9% vs. 37.7%, P = 0.030), and the duration of hospitalization was longer in patients with ascites (11.6 ± 10.7 vs. 8.0 ± 6.6 days, P = 0.020). In conclusion, consideration of age and predisposing disease in addition to ultrasonographic gallbladder findings in children suspected of acute acalculous inflammatory gallbladder disease might result in better outcomes. PMID:27550491

Factors determining poor prognostic outcomes following diabetic hand infections

PubMed Central

Ince, Bilsev; Dadaci, Mehmet; Arslan, Abdullah; Altuntas, Zeynep; Evrenos, Mustafa Kursat; Fatih Karsli, Mehmet

2015-01-01

Background and Objective: Hand ulcers are seen in a small percentage of patients with diabetes. The predisposing factors of diabetic hand varies between different countries. However, the effects of predisposing factors on prognosis are not clear in diabetic hand infections. In this study, our aim was to determine the effects of predisposing factors on poor prognostic outcomes in patients with diabetes mellitus. Methods: Thirty-four patients with diabetes mellitus who were treated and followed up for a hand infection in between 2008 and 2014 were investigated retrospectively. Patients were evaluated according to predisposing factors defined in the literature that included disease period, age, gender, admission time, presence of neuropathy, smoking habits, HbA1c levels at admission time, peripheral vascular disease, end-stage renal disease (ESRD), and trauma. Death and minor/major amputation cases during treatment were defined as poor prognosis. Results: Patients who had ESRD, peripheral neuropathy, or an HbA1c level greater than 10% had significantly higher amputation rates. Conclusions: Peripheral neuropathy, ESRD, and HbA1c levels greater than 10% at the time of admission were determined as poor prognosis criteria for diabetic hand treatment. PMID:26150838

Factors Influencing Cecal Intubation Time during Retrograde Approach Single-Balloon Enteroscopy

PubMed Central

Chen, Peng-Jen; Shih, Yu-Lueng; Huang, Hsin-Hung; Hsieh, Tsai-Yuan

2014-01-01

Background and Aim. The predisposing factors for prolonged cecal intubation time (CIT) during colonoscopy have been well identified. However, the factors influencing CIT during retrograde SBE have not been addressed. The aim of this study was to determine the factors influencing CIT during retrograde SBE. Methods. We investigated patients who underwent retrograde SBE at a medical center from January 2011 to March 2014. The medical charts and SBE reports were reviewed. The patients' characteristics and procedure-associated data were recorded. These data were analyzed with univariate analysis as well as multivariate logistic regression analysis to identify the possible predisposing factors. Results. We enrolled 66 patients into this study. The median CIT was 17.4 minutes. With univariate analysis, there was no statistical difference in age, sex, BMI, or history of abdominal surgery, except for bowel preparation (P = 0.021). Multivariate logistic regression analysis showed that inadequate bowel preparation (odds ratio 30.2, 95% confidence interval 4.63–196.54; P < 0.001) was the independent predisposing factors for prolonged CIT during retrograde SBE. Conclusions. For experienced endoscopist, inadequate bowel preparation was the independent predisposing factor for prolonged CIT during retrograde SBE. PMID:25505904

Effect of soil property uncertainties on permafrost thaw projections: a calibration-constrained analysis: Modeling Archive

DOE Data Explorer

J.C. Rowland; D.R. Harp; C.J. Wilson; A.L. Atchley; V.E. Romanovsky; E.T. Coon; S.L. Painter

2016-02-02

This Modeling Archive is in support of an NGEE Arctic publication available at doi:10.5194/tc-10-341-2016. This dataset contains an ensemble of thermal-hydro soil parameters including porosity, thermal conductivity, thermal conductivity shape parameters, and residual saturation of peat and mineral soil. The ensemble was generated using a Null-Space Monte Carlo analysis of parameter uncertainty based on a calibration to soil temperatures collected at the Barrow Environmental Observatory site by the NGEE team. The micro-topography of ice wedge polygons present at the site is included in the analysis using three 1D column models to represent polygon center, rim and trough features. The Arctic Terrestrial Simulator (ATS) was used in the calibration to model multiphase thermal and hydrological processes in the subsurface.

Early Detection of Skin Cancer by Microtopography

NASA Astrophysics Data System (ADS)

del Carmen López-Pacheco, María; Acevedo-Martínez, Claudia; Pereira da Cunha Martins Costa, Manuel Filipe; Domínguez-Cherit, Judith; Pichardo, Patricia; Pérez-Zapata, Aura Judith; Ramón-Gallegos, Eva

2004-09-01

The objective of this work was to determine the ruggedness of the skin with benign and malignant lesions. Latex impressions were taken from lesions of skin's patients and were analyzed by the MICROTOP 03.MFC inspection system. For the melanoma lesion it was observed that the average rugosity of this tumor was increased 67% compared with the rugosity of healthy skin. These measures allow us to distinguish significantly from other tumors, as it is the case of the basal cell carcinoma (49%), and benign lesions as the epidermoid cyst (37%) and the seborrhea keratosis (4%). It was observed a direct relation between the rugosity and the malignancy of the lesions. These results indicate that the rugosity is a characteristic that could be useful in the diagnosis of skin cancer.

Don't Think, Just Feel the Music: Individuals with Strong Pavlovian-to-Instrumental Transfer Effects Rely Less on Model-based Reinforcement Learning.

PubMed

Sebold, Miriam; Schad, Daniel J; Nebe, Stephan; Garbusow, Maria; Jünger, Elisabeth; Kroemer, Nils B; Kathmann, Norbert; Zimmermann, Ulrich S; Smolka, Michael N; Rapp, Michael A; Heinz, Andreas; Huys, Quentin J M

2016-07-01

Behavioral choice can be characterized along two axes. One axis distinguishes reflexive, model-free systems that slowly accumulate values through experience and a model-based system that uses knowledge to reason prospectively. The second axis distinguishes Pavlovian valuation of stimuli from instrumental valuation of actions or stimulus-action pairs. This results in four values and many possible interactions between them, with important consequences for accounts of individual variation. We here explored whether individual variation along one axis was related to individual variation along the other. Specifically, we asked whether individuals' balance between model-based and model-free learning was related to their tendency to show Pavlovian interferences with instrumental decisions. In two independent samples with a total of 243 participants, Pavlovian-instrumental transfer effects were negatively correlated with the strength of model-based reasoning in a two-step task. This suggests a potential common underlying substrate predisposing individuals to both have strong Pavlovian interference and be less model-based and provides a framework within which to interpret the observation of both effects in addiction.

Testing of Co-Fermentation of Poultry Manure and Corn Silage

NASA Astrophysics Data System (ADS)

Jędrczak, Andrzej; Królik, Dariusz; Sądecka, Zofia; Myszograj, Sylwia; Suchowska-Kisielewicz, Monika; Bojarski, Jacek

2014-12-01

The development of the production of poultry meat is connected with an increase in the quantity of the manure. The chemical characteristics predisposes this waste to processing by methane fermentation method. This study investigated the influence of ammonia and volatile fat acids on mesophilic anaerobic digestion of poultry manure. The aim of the studies was: to determine the degree of biodegradation of the poultry manure as well as manure and corn silage mixed in various proportions in the process of mesophilic fermentation, to evaluate the impact of mineral nitrogen and volatile fat acids on the course of fermentation, and to establish optimum proportions of these types of waste. The tests confirmed the positive effect of co-fermentation of poultry manure with corn silage. The most favourable ratio for mixing the substrates is the equal percentage of their dry matter in the mixture. With such waste mixing proportions, the degree of degradation of organic substances contained in the manure amounted to 61.8% and was higher than in the mono-digestion of manure and corn silage.

Neural Reward and Punishment Sensitivity in Cigarette Smokers

PubMed Central

Potts, Geoffrey F.; Bloom, Erika; Evans, David E.; Drobes, David J.

2014-01-01

Background Nicotine addiction remains a major public health problem but the neural substrates of addictive behavior remain unknown. One characteristic of smoking behavior is impulsive choice, selecting the immediate reward of smoking despite the potential long-term negative consequences. This suggests that drug users, including cigarette smokers, may be more sensitive to rewards and less sensitive to punishment. Methods We used event-related potentials (ERPs) to test the hypothesis that smokers are more responsive to reward signals and less responsive to punishment, potentially predisposing them to risky behavior. We conducted two experiments, one using a reward prediction design to elicit a Medial Frontal Negativity (MFN) and one using a reward- and punishment-motivated flanker task to elicit an Error Related Negativity (ERN), ERP components thought to index activity in the cortical projection of the dopaminergic reward system. Results and Conclusions The smokers had a greater MFN response to unpredicted rewards, and non-smokers, but not smokers, had a larger ERN on punishment motivated trials indicating that smokers are more reward sensitive and less punishment sensitive than nonsmokers, overestimating the appetitive value and underestimating aversive outcomes of stimuli and actions. PMID:25292454

NEPRILYSIN REGULATES PULMONARY ARTERY SMOOTH MUSCLE CELL PHENOTYPE THROUGH A PDGF RECEPTOR DEPENDENT MECHANISM

PubMed Central

Karoor, Vijaya; Oka, Masahiko; Walchak, Sandra J.; Hersh, Louis B.; Miller, York E.; Dempsey, Edward C.

2013-01-01

Reduced neprilysin (NEP), a cell surface metallopeptidase, which cleaves and inactivates pro-inflammatory and vasoactive peptides, predisposes the lung vasculature to exaggerated remodeling in response to hypoxia. We hypothesize that loss of NEP in pulmonary artery smooth muscle cells (PASMCs) results in increased migration and proliferation. PASMCs isolated from NEP−/− mice exhibited enhanced migration and proliferation in response to serum and PDGF, which was attenuated by NEP replacement. Inhibition of NEP by overexpression of a peptidase dead mutant or knockdown by siRNA in NEP+/+ cells increased migration and proliferation. Loss of NEP led to an increase in Src kinase activity and phosphorylation of PTEN resulting in activation of the PDGF receptor (PDGFR). Knockdown of Src kinase with siRNA or inhibition with PP2 a src kinase inhibitor decreased PDGFRY751 phosphorylation and attenuated migration and proliferation in NEP−/− SMCs. NEP substrates, endothelin-1(ET-1) or fibroblast growth factor-2 (FGF2), increased activation of Src and PDGFR in NEP+/+ cells, which was decreased by an ETAR antagonist, neutralizing antibody to FGF2 and Src inhibitor. Similar to the observations in PASMCs levels of p-PDGFR, p-Src and p-PTEN were elevated in NEP−/− lungs. ETAR antagonist also attenuated the enhanced responses in NEP−/−PASMCs and lungs. Taken together our results suggest a novel mechanism for regulation of PDGFR signaling by NEP substrates involving Src and PTEN. Strategies that increase lung NEP activity/expression or target key downstream effectors, like Src, PTEN or PDGFR, may be of therapeutic benefit in pulmonary vascular disease. PMID:23381789

Predisposing and Enabling Factors Associated with Mammography Use among Hispanic and Non-Hispanic White Women Living in a Rural Area

ERIC Educational Resources Information Center

Tejeda, Silvia; Thompson, Beti; Coronado, Gloria D.; Martin, Diane P.; Heagerty, Patrick J.

2009-01-01

Context: Women who do not receive regular mammograms are more likely than others to have breast cancer diagnosed at an advanced stage. Purpose: To examine predisposing and enabling factors associated with mammography use among Hispanic and non-Hispanic White women. Methods: Baseline data were used from a larger study on cancer prevention in rural…

The Influence of Predisposing, Enabling and Need Factors on Condom Use in Ivory Coast

ERIC Educational Resources Information Center

Ngamini Ngui, Andre

2010-01-01

The main objective of this study was to identify key determinants of condom use in Ivory Coast. Data stem from Ivory Coast Demographic Health Survey (DHS) conducted by ORC Macro in 2005 among a representative sample of 9,686 persons aged 15 - 49. Following the behavioral model, we use logistic regression to assess the effect of predisposing,…

Unerupted lower third molar extractions and their risks for mandibular fracture.

PubMed

Corrêa, Ana Paula Simões; Faverani, Leonardo Perez; Ramalho-Ferreira, Gabriel; Ferreira, Sabrina; Ávila Souza, Francisley; de Oliveira Puttini, Igor; Rangel Garcia-Júnior, Idelmo

2014-05-01

As every surgical procedure extraction of third molars can result in several complications, among them the mandibular angle fracture. Predisposing factors for fracture should be analyzed during and after the surgery. This paper aims to discuss the predisposing factors to the occurrence of mandibular angle fractures during and after the procedure for third molars extraction, as well as surgical principles to avoid this complication.

Identifying Some Factors That Might Predispose Drug Abuse among Learners in a South African Township School

ERIC Educational Resources Information Center

Grobler, R.; Khatite, M.

2012-01-01

This study inquires into some of the factors that might predispose the use and abuse of drugs among secondary school learners in a township school. The objective of this research is to identify these factors and to offer a few suggestions on how the abuse may be prevented. A quantitative research strategy is used and a document analysis technique…

Computed tomography assessment of hip joints in asymptomatic individuals in relation to femoroacetabular impingement.

PubMed

Kang, Alan C L; Gooding, Andrew J; Coates, Mark H; Goh, Tony D; Armour, Paul; Rietveld, John

2010-06-01

Femoroacetabular impingement has become a well-recognized entity predisposing to acetabular labral tears and chondral damage, and subsequently development of osteoarthritis of the hip joint. In the authors' experience, it is common to see bony abnormalities predisposing to femoroacetabular impingement in the contralateral asymptomatic hips in patients with unilateral femoroacetabular impingement. This study was undertaken to investigate the prevalence of bony abnormalities predisposing to femoroacetabular impingement in asymptomatic individuals without exposing study participants to unnecessary radiation. Cross-sectional study; Level of evidence, 4. Fifty individuals (100 hip joints), ranging from 15 to 40 years of age, who were seen at a local hospital between March and August 2008 with abdominal trauma or nonspecific abdominal pain in whom abdominal computed tomography was performed to aid diagnosis were prospectively studied. These patients were not known to have any history of hip-related problems. Raw data from the abdominal computed tomography scan, performed on a 64-slice multidetector computed tomography scanner, were reformatted using bone algorithm into several different planes. Several measurements and observations of the hip joints were made in relation to femoroacetabular impingement. The 100 hip joints from 50 patients with no history of hip problems demonstrated that 39% of the joints (31% of female, 48% of male joints) have at least 1 morphologic aspect predisposing to femoroacetabular impingement. The majority (66% to 100% ) of the findings were bilateral; 33% of female and 52% of male asymptomatic participants in our study had at least 1 predisposing factor for femoroacetabular impingement in 1 or both of their hip joints. Based on the data collected from this study, the acetabular crossover sign had a 71% sensitivity and 88% specificity for detecting acetabular retroversion. Nonquantitative assessment of the femoral head at the anterior, anterolateral, and lateral head/neck junctions demonstrated that 74% of the joints had an aspherical femoral head. The study demonstrated substantial prevalence of bony characteristics predisposing to femoroacetabular impingement in asymptomatic individuals according to the established measurement parameters in current literature.

Identifying the predisposing factors, signs and symptoms of overreaching and overtraining in physical education professionals

PubMed Central

Viana, Ricardo B.; Gentil, Paulo; Lorenço, Vinício S.; Vieira, Carlos A.; Campos, Mário H.; Santos, Douglas A.T.; Silva, Wellington F.; Andrade, Marilia S.; Vancini, Rodrigo L.

2018-01-01

Background It is possible that physical education professionals, especially those who participate in aerobic activities, have predisposing factors, signs and symptoms of overreaching (OVR) and overtraining (OVT) due to a high load and volume of exercise followed by suboptimal recovery time. The present study aimed to identify the predisposing factors, signs and symptoms of OVR and OVT in physical education professionals. Methods A questionnaire consisting of 42 questions (10 questions group) about predisposing factors and signs/symptoms was answered by 132 physical education professionals from both sexes (83 men and 49 women) who were allocated into a resistance training group (RG, n = 74), aerobic training group (AG, n = 20) and resistance and aerobic training group (RAG, n = 38). A mean score was calculated ranging from 1 (completely absent) to 5 (severe) for each question group. A low occurrence of predisposing factors and signs and symptoms of OVR and OVT was considered to be a question group score 4 or lower. Profile of Mood State Questionnaire (POMS) was also applied. Results A mean score of 2.5 ± 0.7, 2.7 ± 0.7 and 2.7 ± 0.8 was found for all question groups for RG, AG and RAG, respectively. Of the total sample, 40.6% trained at least five times/week. The POMS revealed that 67.5% of the RG (n = 50), 80% of the AG (n = 16) and 60.5% of the RAG (n = 23) were classified as having no mood disorders and a standard graphic iceberg was presented. There were no statistical differences (p > 0.05) in the total mood disorders among RG (13.9 ± 24.5), AG (10.3 ± 25.1) and RAG (14.6 ± 27.9) groups. Conclusion Despite the volume of training/body working performed by the physical education professionals surveyed being greater than the recommended to achieve improvements on physical fitness, they did not show predisposing factors, signs or symptoms of OVR and OVT.

Micro-topography and reactivity of implant surfaces: an in vitro study in simulated body fluid (SBF).

PubMed

Gandolfi, M G; Taddei, P; Siboni, F; Perrotti, V; Iezzi, G; Piattelli, A; Prati, C

2015-02-01

The creation of micro-textured dental implant surfaces possessing a stimulating activity represents a challenge in implant dentistry; particularly, the formation of a thin, biologically active, calcium-phosphate layer on their surface could help to strengthen the bond to the surrounding bone. The aim of the present study was to characterize in terms of macrostructure, micro-topography and reactivity in simulated body fluid (SBF), the surface of titanium (Ti) implants blasted with TiO2 particles, acid etched with hydrofluoric acid, and activated with Ca and Mg-containing nanoparticles. Sandblasted and acid-etched implants were analyzed by ESEM-EDX (environmental scanning electron microscope with energy dispersive X-ray system) to study the micromorphology of the surface and to perform elemental X-ray microanalysis (microchemical analyses) and element mapping. ESEM-EDX analyses were performed at time 0 and after a 28-day soaking period in SBF Hank's balanced salt solution (HBSS) following ISO 23317 (implants for surgery—in vitro evaluation for apatite-forming ability of implant materials). Microchemical analyses (weight % and atomic %) and element mapping were carried out to evaluate the relative element content, element distribution, and calcium/phosphorus (Ca/P) atomic ratio. Raman spectroscopy was used to assess the possible presence of impurities due to manufacturing and to investigate the phases formed upon HBSS soaking. Micro-morphological analyses showed a micro-textured, highly rough surface with microgrooves. Microchemical analyses showed compositional differences among the apical, middle, and distal thirds. The micro-Raman analyses of the as-received implant showed the presence of amorphous Ti oxide and traces of anatase, calcite, and a carbonaceous material derived from the decomposition of an organic component of lipidic nature (presumably used as lubricant). A uniform layer of Ca-poor calcium phosphates (CaPs) (Ca/P ratio <1.47) was observed after soaking in HBSS; the detection of the 961 cm⁻¹ Raman band confirms this finding. These implants showed a micro-textured surface supporting the formation of CaPs when immersed in SBF. These properties may likely favor bone anchorage and healing by stimulation of mineralizing cells.

Effects of spatial and temporal resolution on simulated feedbacks from polygonal tundra.

NASA Astrophysics Data System (ADS)

Coon, E.; Atchley, A. L.; Painter, S. L.; Karra, S.; Moulton, J. D.; Wilson, C. J.; Liljedahl, A.

2014-12-01

Earth system land models typically resolve permafrost regions at spatial resolutions grossly larger than the scales of topographic variation. This observation leads to two critical questions: How much error is introduced by this lack of resolution, and what is the effect of this approximation on other coupled components of the Earth system, notably the energy balance and carbon cycle? Here we use the Arctic Terrestrial Simulator (ATS) to run micro-topography resolving simulations of polygonal ground, driven by meteorological data from Barrow, AK, to address these questions. ATS couples surface and subsurface processes, including thermal hydrology, surface energy balance, and a snow model. Comparisons are made between one-dimensional "column model" simulations (similar to, for instance, CLM or other land models typically used in Earth System models) and higher-dimensional simulations which resolve micro-topography, allowing for distributed surface runoff, horizontal flow in the subsurface, and uneven snow distribution. Additionally, we drive models with meteorological data averaged over different time scales from daily to weekly moving windows. In each case, we compare fluxes important to the surface energy balance including albedo, latent and sensible heat fluxes, and land-to-atmosphere long-wave radiation. Results indicate that spatial topography variation and temporal variability are important in several ways. Snow distribution greatly affects the surface energy balance, fundamentally changing the partitioning of incoming solar radiation between the subsurface and the atmosphere. This has significant effects on soil moisture and temperature, with implications for vegetation and decomposition. Resolving temporal variability is especially important in spring, when early warm days can alter the onset of snowmelt by days to weeks. We show that high-resolution simulations are valuable in evaluating current land models, especially in areas of polygonal ground. This work was supported by LANL Laboratory Directed Research and Development Project LDRD201200068DR and by the The Next-Generation Ecosystem Experiments (NGEE Arctic) project. NGEE-Arctic is supported by the Office of Biological and Environmental Research in the DOE Office of Science. LA-UR-14-26227.

Effects of experimental warming and elevated CO2 on surface methane and CO­2 fluxes from a boreal black spruce peatland

NASA Astrophysics Data System (ADS)

Gill, A. L.; Finzi, A.; Giasson, M. A.

2015-12-01

High latitude peatlands represent a major terrestrial carbon store sensitive to climate change, as well as a globally significant methane source. While elevated atmospheric carbon dioxide concentrations and warming temperatures may increase peat respiration and C losses to the atmosphere, reductions in peatland water tables associated with increased growing season evapotranspiration may alter the nature of trace gas emission and increase peat C losses as CO2 relative to methane (CH4). As CH4 is a greenhouse gas with twenty times the warming potential of CO2, it is critical to understand how surface fluxes of CO2 and CH4 will be influenced by factors associated with global climate change. We used automated soil respiration chambers to assess the influence of elevated atmospheric CO2 and whole ecosystem warming on peatland CH4 and CO2 fluxes at the SPRUCE (Spruce and Peatland Responses Under Climatic and Environmental Change) Experiment in northern Minnesota. Belowground warming treatments were initiated in July 2014 and whole ecosystem warming and elevated CO2 treatments began in August 2015. Here we report soil iCO2 and iCH4 flux responses to the first year of belowground warming and the first two months of whole ecosystem manipulation. We also leverage the spatial and temporal density of measurements across the twenty autochambers to assess how physical (i.e., plant species composition, microtopography) and environmental (i.e., peat temperature, water table position, oxygen availability) factors influence observed rates of CH4 and CO2 loss. We find that methane fluxes increased significantly across warming treatments following the first year of belowground warming, while belowground warming alone had little influence on soil CO2 fluxes. Peat microtopography strongly influenced trace gas emission rates, with higher CH4 fluxes in hollow locations and higher CO2 fluxes in hummock locations. While there was no difference in the isotopic composition of the methane fluxes between hollow and hummock locations, δ13CH4 was more depleted in the early and late growing season, indicating a transition from hydrogenotrophic to acetoclastic methanogenesis during periods of high photosynthetic input.

Modeling the spatiotemporal variability in subsurface thermal regimes across a low-relief polygonal tundra landscape

DOE PAGES

Kumar, Jitendra; Collier, Nathan; Bisht, Gautam; ...

2016-09-27

Vast carbon stocks stored in permafrost soils of Arctic tundra are under risk of release to the atmosphere under warming climate scenarios. Ice-wedge polygons in the low-gradient polygonal tundra create a complex mosaic of microtopographic features. This microtopography plays a critical role in regulating the fine-scale variability in thermal and hydrological regimes in the polygonal tundra landscape underlain by continuous permafrost. Modeling of thermal regimes of this sensitive ecosystem is essential for understanding the landscape behavior under the current as well as changing climate. Here, we present an end-to-end effort for high-resolution numerical modeling of thermal hydrology at real-world fieldmore » sites, utilizing the best available data to characterize and parameterize the models. We also develop approaches to model the thermal hydrology of polygonal tundra and apply them at four study sites near Barrow, Alaska, spanning across low to transitional to high-centered polygons, representing a broad polygonal tundra landscape. A multiphase subsurface thermal hydrology model (PFLOTRAN) was developed and applied to study the thermal regimes at four sites. Using a high-resolution lidar digital elevation model (DEM), microtopographic features of the landscape were characterized and represented in the high-resolution model mesh. The best available soil data from field observations and literature were utilized to represent the complex heterogeneous subsurface in the numerical model. Simulation results demonstrate the ability of the developed modeling approach to capture – without recourse to model calibration – several aspects of the complex thermal regimes across the sites, and provide insights into the critical role of polygonal tundra microtopography in regulating the thermal dynamics of the carbon-rich permafrost soils. Moreover, areas of significant disagreement between model results and observations highlight the importance of field-based observations of soil thermal and hydraulic properties for modeling-based studies of permafrost thermal dynamics, and provide motivation and guidance for future observations that will help address model and data gaps affecting our current understanding of the system.« less

The distribution of organic material and its contribution to the micro-topography of particles from wettable and water repellent soils

NASA Astrophysics Data System (ADS)

Bryant, Rob; Cheng, Shuying; Doerr, Stefan H.; Wright, Chris J.; Bayer, Julia V.; Williams, Rhodri P.

2010-05-01

Organic coatings on mineral particles will mask the physic-chemical properties of the underlying mineral surface. Surface images and force measurements obtained using atomic force microscopy (AFM) provide information about the nature of and variability in surfaces properties at the micro- to nano-scale. As AFM technology and data processing advance it is anticipated that a significant amount of information will be obtained simultaneously from individual contacts made at high frequency in non-contact or tapping mode operation. For present purposes the surfaces of model materials (smooth glass surfaces and acid-washed sand (AWS)) provide an indication of the dependency of the so-called AFM phase image on the topographic image (which is obtained synoptically). Pixel wise correlation of these images reveals how the modulation of an AFM probe is affected when topographic features are encountered. Adsorption of soil-derived humic acid (HA) or lecithin (LE), used here as an example for natural organic material, on these surfaces provides a soft and compliant, albeit partial, covering on the mineral which modifies the topography and the response of an AFM tip as it partially indents the soft regions (which contributes depth to the phase image). This produces a broadening on the data domain in the topographic/phase scatter diagram. Two dimensional classifications of these data, together with those obtained from sand particles drawn from water repellent and wettable soils, suggest that these large adsorbate molecules appear to have little preference to attach to particular topographic features or elevations. It appears that they may effectively remain on the surface at the point of initial contact. If organic adsorbates present a hydrophobic outer surface, then it seems possible that elevated features will not be immune from this and provide scope for a local, albeit, small contribution to the expression of super-hydrophobicity. It is therefore speculated here that the water repellency of a soil is the result of not only of particle surface chemistry and soil pore space geometry, but also of the micro-topography generated by organic material adsorbed on particle surfaces.

Early identification of patients at risk of acute lung injury: evaluation of lung injury prediction score in a multicenter cohort study.

PubMed

Gajic, Ognjen; Dabbagh, Ousama; Park, Pauline K; Adesanya, Adebola; Chang, Steven Y; Hou, Peter; Anderson, Harry; Hoth, J Jason; Mikkelsen, Mark E; Gentile, Nina T; Gong, Michelle N; Talmor, Daniel; Bajwa, Ednan; Watkins, Timothy R; Festic, Emir; Yilmaz, Murat; Iscimen, Remzi; Kaufman, David A; Esper, Annette M; Sadikot, Ruxana; Douglas, Ivor; Sevransky, Jonathan; Malinchoc, Michael

2011-02-15

Accurate, early identification of patients at risk for developing acute lung injury (ALI) provides the opportunity to test and implement secondary prevention strategies. To determine the frequency and outcome of ALI development in patients at risk and validate a lung injury prediction score (LIPS). In this prospective multicenter observational cohort study, predisposing conditions and risk modifiers predictive of ALI development were identified from routine clinical data available during initial evaluation. The discrimination of the model was assessed with area under receiver operating curve (AUC). The risk of death from ALI was determined after adjustment for severity of illness and predisposing conditions. Twenty-two hospitals enrolled 5,584 patients at risk. ALI developed a median of 2 (interquartile range 1-4) days after initial evaluation in 377 (6.8%; 148 ALI-only, 229 adult respiratory distress syndrome) patients. The frequency of ALI varied according to predisposing conditions (from 3% in pancreatitis to 26% after smoke inhalation). LIPS discriminated patients who developed ALI from those who did not with an AUC of 0.80 (95% confidence interval, 0.78-0.82). When adjusted for severity of illness and predisposing conditions, development of ALI increased the risk of in-hospital death (odds ratio, 4.1; 95% confidence interval, 2.9-5.7). ALI occurrence varies according to predisposing conditions and carries an independently poor prognosis. Using routinely available clinical data, LIPS identifies patients at high risk for ALI early in the course of their illness. This model will alert clinicians about the risk of ALI and facilitate testing and implementation of ALI prevention strategies. Clinical trial registered with www.clinicaltrials.gov (NCT00889772).

Predisposing characteristics, enabling resources and need as predictors of utilization and clinical outcomes for veterans receiving mental health services.

PubMed

Fasoli, DiJon R; Glickman, Mark E; Eisen, Susan V

2010-04-01

Though demand for mental health services (MHS) among US veterans is increasing, MHS utilization per veteran is decreasing. With health and social service needs competing for limited resources, it is important to understand the association between patient factors, MHS utilization, and clinical outcomes. We use a framework based on Andersen's behavioral model of health service utilization to examine predisposing characteristics, enabling resources, and clinical need as predictors of MHS utilization and clinical outcomes. This was a prospective observational study of veterans receiving inpatient or outpatient MHS through Veterans Administration programs. Clinician ratings (Global Assessment of Functioning [GAF]) and self-report assessments (Behavior and Symptom Identification Scale-24) were completed for 421 veterans at enrollment and 3 months later. Linear and logistic regression analyses were conducted to examine: (1) predisposing characteristics, enabling resources, and need as predictors of MHS inpatient, residential, and outpatient utilization and (2) the association between individual characteristics, utilization, and clinical outcomes. Being older, female, having greater clinical need, lack of enabling resources (employment, stable housing, and social support), and easy access to treatment significantly predicted greater MHS utilization at 3-month follow-up. Less clinical need and no inpatient psychiatric hospitalization predicted better GAF and Behavior and Symptom Identification Scale-24 scores. White race and residential treatment also predicted better GAF scores. Neither enabling resources, nor number of outpatient mental health visits predicted clinical outcomes. This application of Andersen's behavioral model of health service utilization confirmed associations between some predisposing characteristics, need, and enabling resources on MHS utilization but only predisposing characteristics, need, and utilization were associated with clinical outcomes.

Contextual and individual factors associated with dental services utilisation by Brazilian adults: A multilevel analysis

PubMed Central

2018-01-01

Background Inequalities in the utilisation of dental services in Brazil are remarkable. The aim of this study was to evaluate the association of contextual and individual factors with the utilisation of dental services by Brazilian adults using the Andersen’s behavioural model. Methods Individual-level data from 27,017 adults residents in the State capitals who were interviewed in the 2013 Brazilian National Health Survey were pooled with contextual city-level data. The outcomes were non-utilisation of dental services and last dental visit over 12 months ago. Individual predisposing variables were age, sex, race/skin colour, schooling and social network. Individual enabling variables included income, health insurance and registration in primary health care. Individual need variables were self-perceived dental health and self-reported missing teeth. Multilevel logistic regression models were performed to estimate odds ratio (OR) and 95% confidence intervals (95% CIs) of the association of contextual and individual predisposing, enabling and need-related variables with dental services outcomes. Results Predisposing (OR = 0.89; 95% CI 0.81–0.97) and enabling (OR = 0.90; 95% CI 0.85–0.96) contextual factors were associated with non-utilisation of dental services. Individual predisposing (sex, race/skin colour, schooling), enabling (income, health insurance) and need (self-perceived oral health, missing teeth) were associated with non-utilisation of dental services and last dental visit over 12 months ago. The latter was also associated with other individual predisposing (age, social network) and need (eating difficulties due to oral problems) characteristics. Conclusions Individual and contextual determinants influenced dental services utilisation in Brazilian adults. These factors should be on the policy agenda and considered in the organisation of health services aiming to reduce oral health inequalities related to access and utilisation of dental services. PMID:29420660

Contextual and individual factors associated with dental services utilisation by Brazilian adults: A multilevel analysis.

PubMed

Herkrath, Fernando José; Vettore, Mario Vianna; Werneck, Guilherme Loureiro

2018-01-01

Inequalities in the utilisation of dental services in Brazil are remarkable. The aim of this study was to evaluate the association of contextual and individual factors with the utilisation of dental services by Brazilian adults using the Andersen's behavioural model. Individual-level data from 27,017 adults residents in the State capitals who were interviewed in the 2013 Brazilian National Health Survey were pooled with contextual city-level data. The outcomes were non-utilisation of dental services and last dental visit over 12 months ago. Individual predisposing variables were age, sex, race/skin colour, schooling and social network. Individual enabling variables included income, health insurance and registration in primary health care. Individual need variables were self-perceived dental health and self-reported missing teeth. Multilevel logistic regression models were performed to estimate odds ratio (OR) and 95% confidence intervals (95% CIs) of the association of contextual and individual predisposing, enabling and need-related variables with dental services outcomes. Predisposing (OR = 0.89; 95% CI 0.81-0.97) and enabling (OR = 0.90; 95% CI 0.85-0.96) contextual factors were associated with non-utilisation of dental services. Individual predisposing (sex, race/skin colour, schooling), enabling (income, health insurance) and need (self-perceived oral health, missing teeth) were associated with non-utilisation of dental services and last dental visit over 12 months ago. The latter was also associated with other individual predisposing (age, social network) and need (eating difficulties due to oral problems) characteristics. Individual and contextual determinants influenced dental services utilisation in Brazilian adults. These factors should be on the policy agenda and considered in the organisation of health services aiming to reduce oral health inequalities related to access and utilisation of dental services.

Early Identification of Patients at Risk of Acute Lung Injury

PubMed Central

Gajic, Ognjen; Dabbagh, Ousama; Park, Pauline K.; Adesanya, Adebola; Chang, Steven Y.; Hou, Peter; Anderson, Harry; Hoth, J. Jason; Mikkelsen, Mark E.; Gentile, Nina T.; Gong, Michelle N.; Talmor, Daniel; Bajwa, Ednan; Watkins, Timothy R.; Festic, Emir; Yilmaz, Murat; Iscimen, Remzi; Kaufman, David A.; Esper, Annette M.; Sadikot, Ruxana; Douglas, Ivor; Sevransky, Jonathan

2011-01-01

Rationale: Accurate, early identification of patients at risk for developing acute lung injury (ALI) provides the opportunity to test and implement secondary prevention strategies. Objectives: To determine the frequency and outcome of ALI development in patients at risk and validate a lung injury prediction score (LIPS). Methods: In this prospective multicenter observational cohort study, predisposing conditions and risk modifiers predictive of ALI development were identified from routine clinical data available during initial evaluation. The discrimination of the model was assessed with area under receiver operating curve (AUC). The risk of death from ALI was determined after adjustment for severity of illness and predisposing conditions. Measurements and Main Results: Twenty-two hospitals enrolled 5,584 patients at risk. ALI developed a median of 2 (interquartile range 1–4) days after initial evaluation in 377 (6.8%; 148 ALI-only, 229 adult respiratory distress syndrome) patients. The frequency of ALI varied according to predisposing conditions (from 3% in pancreatitis to 26% after smoke inhalation). LIPS discriminated patients who developed ALI from those who did not with an AUC of 0.80 (95% confidence interval, 0.78–0.82). When adjusted for severity of illness and predisposing conditions, development of ALI increased the risk of in-hospital death (odds ratio, 4.1; 95% confidence interval, 2.9–5.7). Conclusions: ALI occurrence varies according to predisposing conditions and carries an independently poor prognosis. Using routinely available clinical data, LIPS identifies patients at high risk for ALI early in the course of their illness. This model will alert clinicians about the risk of ALI and facilitate testing and implementation of ALI prevention strategies. Clinical trial registered with www.clinicaltrials.gov (NCT00889772). PMID:20802164

Splenic Abscess Associated with Endocarditis in a Patient on Hemodialysis: A Case Report

PubMed Central

Kim, Hyun Soo; Cho, Min Seok; Hwang, Seung Hwan; Ma, Seong Kwon; Kim, Soo Wan; Kim, Nam Ho

2005-01-01

Splenic abscess is an unusual condition usually seen in immunocompromised patients or associated with intravenous drug abuses. Several conditions including trauma, immunodeficiency, corticosteroid and/or immunosuppressive therapy and diabetes mellitus have been listed under the predisposing factors for a splenic abscess. Splenic abscess in a patient on hemodialysis is a rare but life-threatening condition if not corrected. We describe a case of splenic abscess with bacterial endocarditis on maintenance hemodialysis. He had staphylococcal septicemia secondary to bacterial endocarditis at the mitral valve from the dialysis accesssite infection. Although hematologic seeding from endocarditis has been the predisposing factor for splenic abscess, we postulate that access-site infections may predispose hemodialysis patients to splenic abscess. Splenic abscess may be considered as one of the causes when patients on hemodialysis develop unexplained fever. PMID:15832007

Cervical spine joint hypermobility: a possible predisposing factor for new daily persistent headache.

PubMed

Rozen, T D; Roth, J M; Denenberg, N

2006-10-01

The objective of this study was to suggest that joint hypermobility (specifically of the cervical spine) is a predisposing factor for the development of new daily persistent headache (NDPH). Twelve individuals (10 female, 2 male) with primary NDPH were evaluated by one of two physical therapists. Each patient was tested for active cervical range of motion and for the presence of excessive intersegmental vertebral motion in the cervical spine. All patients were screened utilizing the Beighton score, which determines degree of systemic hypermobility. Eleven of the 12 NDPH patients were found to have cervical spine joint hypermobility. Ten of the 12 NDPH patients had evidence of widespread joint hypermobility with the Beighton score. Based on our findings we suggest that joint hypermobility, specifically of the cervical spine, may be a predisposing factor for the development of NDPH.

Genotyping of HLA-I and HLA-II alleles in Chinese patients with paraneoplastic pemphigus.

PubMed

Liu, Q; Bu, D-F; Li, D; Zhu, X-J

2008-03-01

Class I and class II HLA genes are thought to play a role in the immunopathogenesis of bullous dermatoses such as pemphigus vulgaris and pemphigus foliaceus, but we know little about the genetic background of paraneoplastic pemphigus (PNP) in Chinese patients. To identify class I and class II HLA alleles by genotyping in Chinese patients with PNP, and to find out the possible association between HLA alleles and disease susceptibility. Nineteen Chinese patients with PNP were enrolled in this study. HLA-A, B, C, DRB1 and DQB1 alleles were typed by polymerase chain reaction and a colour-coded sequence-specific oligonucleotide probes method. The frequencies of HLA-B*4002/B*4004, B*51, B*52, Cw*14, DQB1*0301, DRB1*08 and DRB1*11 were relatively prevalent in Chinese Han patients with PNP in comparison with normal controls. After correction for multiple comparisons, Cw*14 remained statistically significant, and the other alleles were unremarkable in these patients. The genetic background predisposing to PNP may be different in patients from various races and areas. HLA-Cw*14 may be the predisposing allele to PNP in Chinese patients, which is different from the predisposing allele in French patients with PNP and the alleles predisposing to pemphigus vulgaris and pemphigus foliaceus.

POLE mutations in families predisposed to cutaneous melanoma.

PubMed

Aoude, Lauren G; Heitzer, Ellen; Johansson, Peter; Gartside, Michael; Wadt, Karin; Pritchard, Antonia L; Palmer, Jane M; Symmons, Judith; Gerdes, Anne-Marie; Montgomery, Grant W; Martin, Nicholas G; Tomlinson, Ian; Kearsey, Stephen; Hayward, Nicholas K

2015-12-01

Germline mutations in the exonuclease domain of POLE have been shown to predispose to colorectal cancers and adenomas. POLE is an enzyme involved in DNA repair and chromosomal DNA replication. In order to assess whether such mutations might also predispose to cutaneous melanoma, we interrogated whole-genome and exome data from probands of 34 melanoma families lacking pathogenic mutations in known high penetrance melanoma susceptibility genes: CDKN2A, CDK4, BAP1, TERT, POT1, ACD and TERF2IP. We found a novel germline mutation, POLE p.(Trp347Cys), in a 7-case cutaneous melanoma family. Functional assays in S. pombe showed that this mutation led to an increased DNA mutation rate comparable to that seen with a Pol ε mutant with no exonuclease activity. We then performed targeted sequencing of POLE in 1243 cutaneous melanoma cases and found that a further ten probands had novel or rare variants in the exonuclease domain of POLE. Although this frequency is not significantly higher than that in unselected Caucasian controls, we observed multiple cancer types in the melanoma families, suggesting that some germline POLE mutations may predispose to a broad spectrum of cancers, including melanoma. In addition, we found the first mutation outside the exonuclease domain, p.(Gln520Arg), in a family with an extensive history of colorectal cancer.

Historical descriptions of some soils and landscapes of Texas

NASA Astrophysics Data System (ADS)

Schulze, Darrell G.

Europeans explorers, immigrants, and travelers have been crisscrossing Texas for almost 5 centuries, recording their observations of soils and landscapes through the lens of their own times. In the early 16th century, Cabeza de Vaca was struck by how the natives among whom he lived used soil as a part of their diet. In the 17th century, as a member of the La Salle expedition to Texas, Henri Joutel described the soils and landscapes he saw in considerable detail, perhaps with an eye to possible future French settlement. To 19th century immigrants, the soil was the source of their future wealth, but also, so they thought, of the source of the various illnesses that inflicted them. With their distinctive micro-topography and large cracks when dry, Vertisols have elicited some of the most interesting early descriptions of Texas soils.

Infective Endocarditis in Children in Italy from 2000 to 2015.

PubMed

Esposito, Susanna; Mayer, Alessandra; Krzysztofiak, Andrzej; Garazzino, Silvia; Lipreri, Rita; Galli, Luisa; Osimani, Patrizia; Fossali, Emilio; Di Gangi, Maria; Lancella, Laura; Denina, Marco; Pattarino, Giulia; Montagnani, Carlotta; Salvini, Filippo; Villani, Alberto; Principi, Nicola; Italian Pediatric Infective Endocarditis Registry

2016-01-01

The Italian Society for Pediatric Infectious Diseases created a registry on children with infective endocarditis (IE) hospitalized in Italy. A cross-sectional survey was conducted on patients hospitalized due to IE in Italian paediatric wards between January 1, 2000, and June 30, 2015. Over the 15-year study period, 47 IE episodes were observed (19 males; age range, 2-17 years). Viridans Streptococci were the most common pathogens among patients with predisposing cardiac conditions and Staphylococcus aureus among those without (37.9% vs. 5.5%, p = 0.018, and 6.9% vs. 27.8%, p = 0.089, respectively). Six of the 7 (85.7%) S. aureus strains were methicillin-resistant. The majority of patients with and without predisposing cardiac conditions recovered without any complications. In Italy, paediatric IE develops without any previous predisposing factors in a number of children, methicillin-resistant S. aureus has emerged as a common causative agent and the therapeutic approach is extremely variable.

Ocular infections caused by Scedosporium apiospermum: A case series.

PubMed

Ramakrishnan, Seema; Mandlik, Kunal; Sathe, Tejashree Sanket; Gubert, Joseph; Krishnan, Thiruvengada; Baskaran, Prabu

2018-01-01

The aim of our retrospective study is to report a case series of ocular infections caused by a rare fungus, Scedosporium apiospermum, in a South Indian population. Thirteen cases of culture-positive S. apiospermum infections diagnosed between January 2011 and March 2016 were included in this study. The parameters evaluated were predisposing factors, treatment and final clinical outcome. The most common mode of presentation was keratitis (84.6%) followed by sclerokeratitis (15.3%). The predisposing factors involved were unspecified foreign body injury (30.7%), organic matter injury (15.3%), uncontrolled diabetes (7.6%), and recent manual small-incision cataract surgery (7.6%). Five cases (38.46%) had no predisposing factor. Of the 11 keratitis cases, nine (69.2%) responded well to combination medical therapy while one case (7.6%) required therapeutic keratoplasty. One case was lost to follow-up. Both cases which presented with sclerokeratitis showed no response to medico-surgical treatment progressing to panophthalmitis and evisceration.

Predisposing factors for early retirement in patients with schizophrenia in Germany.

PubMed

Schnabel, Reinhard; Friedel, Heiko; Erfurth, Andreas; Angermayer, Matthias; Clouth, Johannes; Eichmann, Florian

2008-08-01

Although early retirement causes major changes in the life of schizophrenic patients and is among the major cost factors to be covered by payers, the causes leading to early retirement of schizophrenic patients have not been investigated in detail. Therefore, the objective of this retrospective non-interventional case-control study was to generate hypotheses on predisposing factors for early retirement in schizophrenia. Logistic regression was used to explore potential predisposing parameters with regard to their effect on the outcome early retirement. As the study results indicate, schizophrenia severity, assistance or care in the patient's everyday life, age and antipsychotic treatment with typical antipsychotics are linked to the occurrence of early retirement. Further research should be planned to confirm or refute the hypotheses determined in this retrospective analysis and to determine whether atypical antipsychotics could help to avoid early retirement and to improve the situation of schizophrenic patients.

Phenotypic and genotypic heterogeneity of Lynch syndrome: a complex diagnostic challenge.

PubMed

Lynch, Henry T; Lanspa, Stephen; Shaw, Trudy; Casey, Murray Joseph; Rendell, Marc; Stacey, Mark; Townley, Theresa; Snyder, Carrie; Hitchins, Megan; Bailey-Wilson, Joan

2018-07-01

Lynch syndrome is the hereditary disorder that most frequently predisposes to colorectal cancer as well as predisposing to a number of extracolonic cancers, most prominently endometrial cancer. It is caused by germline mutations in the mismatch repair genes. Both its phenotype and genotype show marked heterogeneity. This review gives a historical overview of the syndrome, its heterogeneity, its genomic landscape, and its implications for complex diagnosis, genetic counseling and putative implications for immunotherapy.

Vulvovaginal Candidiasis in Aminu Kano Teaching Hospital, North-West Nigeria: Hospital-Based Epidemiological Study

PubMed Central

Ugwa, EA

2015-01-01

Background: Vulvovaginal candidiasis (VVC) remains a common problem worldwide and the role of douching as a predisposing factor is unclear. Aim: This study was undertaken to highlight the prevalence and predisposing factors of VVC in North-west Nigeria. Subjects and Methods: This was a prospective study done at Aminu Kano Teaching Hospital (AKTH), North-west. AKTH is a 500-bed tertiary hospital located in Kano, the most populous state in Nigeria. Ethical clearance was obtained. Three hundred patients with VVC were recruited from the gynecologic and general outpatients’ clinics of AKTH. Research structured questionnaires were used to obtain sociodemographic and clinical information. The data obtained were analyzed using SPSS version 16.0 statistical software (SPSS Inc., Chicago IL, USA). Frequency, mean and simple percentages were used to analyze data. Result: Candida albicans was the most frequent cause of the positive high vaginal swabs constituting 84.5% (316/374) while Proteus vulgaris was the least frequent cause constituting 0.53% (2/374). Fifty-three percent (143/270) of those with VVC were aged 26–35 years; the married were 80% (216/270) and those who were unmarried were 20% (54/270). Douching was the commonest predisposing factor occurring in 42.5% (115/270) of cases. Conclusion: VVC was the most prevalent cause of vaginosis in North-west Nigeria, and douching was the commonest predisposing factor. PMID:26229716

Does a PBL-based medical curriculum predispose training in specific career paths? A systematic review of the literature.

PubMed

Tsigarides, Jordan; Wingfield, Laura R; Kulendran, Myutan

2017-01-07

North American medical schools have used problem-based learning (PBL) structured medical education for more than 60 years. However, it has only recently been introduced in other medical schools outside of North America. Since its inception, there has been the debate on whether the PBL learning process predisposes students to select certain career paths. To review available evidence to determine the predisposition of specific career paths when undertaking a PBL-based medical curriculum. The career path trajectory was determined as measured by official Matching Programs, self-reported questionnaires and surveys, and formally defined career development milestones. A systematic literature review was performed. PubMed, Medline, Cochrane and ERIC databases were analysed in addition to reference lists for appropriate inclusion. Eleven studies fitting the inclusion criteria were identified. The majority of studies showed that PBL did not predispose a student to a career in a specific speciality (n = 7 out of 11 studies, 64%). However, three studies reported a significantly increased number of PBL graduates working in primary care compared to those from a non-PBL curriculum. PBL has been shown not to predispose medical students to a career in General Practice or any other speciality. Furthermore, a greater number of similar studies are required before a definitive conclusion can be made in the future.

Exposure to an obesogenic diet during adolescence leads to abnormal maturation of neural and behavioral substrates underpinning fear and anxiety.

PubMed

Vega-Torres, Julio David; Haddad, Elizabeth; Lee, Jeong Bin; Kalyan-Masih, Priya; Maldonado George, Wanda I; López Pérez, Leonardo; Piñero Vázquez, Darla M; Arroyo Torres, Yaría; Santiago Santana, José M; Obenaus, Andre; Figueroa, Johnny D

2018-05-01

Post-traumatic stress disorder (PTSD) and obesity are highly prevalent in adolescents. Emerging findings from our laboratory and others are consistent with the novel hypothesis that obese individuals may be predisposed to developing PTSD. Given that aberrant fear responses are pivotal in the pathogenesis of PTSD, the objective of this study was to determine the impact of an obesogenic Western-like high-fat diet (WD) on neural substrates associated with fear. Adolescent Lewis rats (n = 72) were fed with either the experimental WD (41.4% kcal from fat) or the control diet. The fear-potentiated startle paradigm was used to determine sustained and phasic fear responses. Diffusion tensor imaging metrics and T2 relaxation times were used to determine the structural integrity of the fear circuitry including the medial prefrontal cortex (mPFC) and the basolateral complex of the amygdala (BLA). The rats that consumed the WD exhibited attenuated fear learning and fear extinction. These behavioral impairments were associated with oversaturation of the fear circuitry and astrogliosis. The BLA T2 relaxation times were significantly decreased in the WD rats relative to the controls. We found elevated fractional anisotropy in the mPFC of the rats that consumed the WD. We show that consumption of a WD may lead to long-lasting damage to components of the fear circuitry. Our findings demonstrate that consumption of an obesogenic diet during adolescence has a profound impact in the maturation of the fear neurocircuitry. The implications of this research are significant as they identify potential biomarkers of risk for psychopathology in the growing obese population. Copyright © 2018 Elsevier Inc. All rights reserved.

Evaluation of potential variables contributing to the development and duration of plantar lesions in a population of aquarium-maintained African penguins (Spheniscus demersus).

PubMed

Erlacher-Reid, Claire; Dunn, J Lawrence; Camp, Tracy; Macha, Laurie; Mazzaro, Lisa; Tuttle, Allison D

2012-01-01

Bumblefoot (pododermatitis), often described as the most significant environmental disease of captive penguins, is commonly due to excessive pressure or trauma on the plantar surface of the avian foot, resulting in inflammation or necrosis and causing severe swelling, abrasions, or cracks in the skin. Although not formally evaluated in penguins, contributing factors for bumblefoot are thought to be similar to those initiating the condition in raptors and poultry. These factors include substrate, body weight, and lack of exercise. The primary purpose of this retrospective study was to evaluate variables potentially contributing to the development and duration of plantar lesions in aquarium-maintained African penguins (Spheniscus demersus), including sex, weight, age, season, exhibit activity, and territory substrate. Results indicate that males develop significantly more plantar lesions than females. Penguins weighing between 3.51 and 4.0 kg develop plantar lesions significantly more often than penguins weighing between 2.5 and 3.5 kg, and because male African penguins ordinarily weigh significantly more than females, weight is likely a contributing factor in the development of lesions in males compared with females. Significantly more plantar lesions were observed in penguins standing for greater than 50% of their time on exhibit than swimming. Penguins occupying smooth concrete territories developed more plantar lesions compared with penguins occupying grate territories. Recommendations for minimizing bumblefoot in African penguins include training penguins for monthly foot examinations for early detection of plantar lesions predisposing for the disease, encouraging swimming activity, and replacing smooth surfaces on exhibit with surfaces providing variable degrees of pressure and texture on the feet. © 2011 Wiley Periodicals, Inc.

Enhancement of antibiotic activity by efflux inhibitors against multidrug resistant Mycobacterium tuberculosis clinical isolates from Brazil

PubMed Central

Coelho, Tatiane; Machado, Diana; Couto, Isabel; Maschmann, Raquel; Ramos, Daniela; von Groll, Andrea; Rossetti, Maria L.; Silva, Pedro A.; Viveiros, Miguel

2015-01-01

Drug resistant tuberculosis continues to increase and new approaches for its treatment are necessary. The identification of M. tuberculosis clinical isolates presenting efflux as part of their resistant phenotype has a major impact in tuberculosis treatment. In this work, we used a checkerboard procedure combined with the tetrazolium microplate-based assay (TEMA) to study single combinations between antituberculosis drugs and efflux inhibitors (EIs) against multidrug resistant M. tuberculosis clinical isolates using the fully susceptible strain H37Rv as reference. Efflux activity was studied on a real-time basis by a fluorometric method that uses ethidium bromide as efflux substrate. Quantification of efflux pump genes mRNA transcriptional levels were performed by RT-qPCR. The fractional inhibitory concentrations (FIC) indicated synergistic activity for the interactions between isoniazid, rifampicin, amikacin, ofloxacin, and ethidium bromide plus the EIs verapamil, thioridazine and chlorpromazine. The FICs ranged from 0.25, indicating a four-fold reduction on the MICs, to 0.015, 64-fold reduction. The detection of active efflux by real-time fluorometry showed that all strains presented intrinsic efflux activity that contributes to the overall resistance which can be inhibited in the presence of the EIs. The quantification of the mRNA levels of the most important efflux pump genes on these strains shows that they are intrinsically predisposed to expel toxic compounds as the exposure to subinhibitory concentrations of antibiotics were not necessary to increase the pump mRNA levels when compared with the non-exposed counterpart. The results obtained in this study confirm that the intrinsic efflux activity contributes to the overall resistance in multidrug resistant clinical isolates of M. tuberculosis and that the inhibition of efflux pumps by the EIs can enhance the clinical effect of antibiotics that are their substrates. PMID:25972842

A role for suppressed skeletal muscle thermogenesis in pathways from weight fluctuations to the insulin resistance syndrome.

PubMed

Dulloo, A G

2005-08-01

An impressive body of epidemiological evidence suggests that a history of large perturbations in body weight earlier in life, independently of excess weight, is a risk factor for later development of insulin-related complications, namely central obesity, type 2 diabetes and cardiovascular disease. Such an increased risk has been reported in men and women who in young adulthood experienced weight fluctuations that involved weight recovery after weight loss caused by disease, famine or voluntary 'yoyo' dieting, and is particularly strong when the weight fluctuations occurred much earlier in life and are characterized by catch-up growth after foetal and/or neonatal growth retardation. As the phase of weight recovery/catch-up growth is associated with both hyperinsulinaemia and an accelerated rate for recovering fat mass (i.e. catch-up fat), the questions arise as to whether, why and how processes that regulate catch-up fat might predispose to hyperinsulinaemia and to insulin-related diseases. In addressing these issues, this paper first reviews evidence for the existence of an adipose-specific control of thermogenesis, whose suppression contributes to the phenomenon of catch-up fat during weight recovery/catch-up growth. It subsequently concentrates upon recent findings suggesting that: (i) such suppression of thermogenesis directed at catch-up fat is accompanied by a redistribution of glucose from skeletal muscle to white adipose tissue, and (ii) substrate cycling between de novo lipogenesis and lipid oxidation can operate as a thermogenic effector in skeletal muscle in response to signalling interactions between leptin and insulin - two key 'adiposity' hormones implicated in the peripheral control of substrate metabolism. These new findings are integrated into the proposal that, in its 'evolutionary adaptive' role to spare glucose for rapid rebuilding of the fat stores, suppressed thermogenesis in skeletal muscle - via inhibition of substrate cycling between de novo lipogenesis and lipid oxidation - confers to the phase of weight recovery/catch-up growth its high sensitivity towards the development of insulin resistance and hyperinsulinaemia, and hence towards diseases that are clustered around the insulin resistance syndrome.

The predisposing factors for the heterotopic ossification after cervical artificial disc replacement.

PubMed

Yi, Seong; Shin, Dong Ah; Kim, Keung Nyun; Choi, Gwihyun; Shin, Hyun Chul; Kim, Keun Su; Yoon, Do Heum

2013-09-01

Heterotopic ossification (HO) is defined as a formation of bone outside the skeletal system. The reported HO occurrence rate in cervical artificial disc replacement (ADR) is unexpectedly high and is known to vary. However, the predisposing factors for HO in cervical ADR have not yet been elucidated. Investigation of the predisposing factors of HO in cervical arthroplasty and the relationship between degeneration of the cervical spine and HO occurrence. Retrospective study to discover predisposing factors of HO in cervical arthroplasty. A total of 170 patients who underwent cervical ADR were enrolled including full follow-up clinical and radiologic data. Radiologic outcomes were assessed by identification of HOs according to McAfee's classifications. This study enrolled a total of 170 patients who underwent cervical ADR. Pre-existing degenerative change included anterior or posterior osteophytes, ossification of the anterior longitudinal ligament, posterior longitudinal ligament, or ligamentum nuchae. The relationships between basic patient data, pre-existing degenerative change, and HO were investigated using linear logistic regression analysis. Among all 170 patients, HO was found in 69 patients (40.6%). Among the postulated predisposing factors, only male gender and artificial disc device type were shown to be statistically significant. Unexpectedly, preoperative degenerative changes in the cervical spine exerted no significant influence on the occurrence of HOs. The odds ratio of male gender compared with female gender was 2.117. With regard to device type, the odds ratios of Mobi-C (LDR medical, Troyes, France) and ProDisc-C (Synthes, Inc., West Chester, PA, USA) were 5.262 and 7.449, respectively, compared with the Bryan disc. Definite differences in occurrence rate according to the gender of patients and the prosthesis type were identified in this study. Moreover, factors indefinably expected to influence HO in the past were not shown to be risk factors thereof, the results of which may be meaningful to future studies. Copyright © 2013 Elsevier Inc. All rights reserved.

Bowel Angioedema Associated With Iodinated Contrast Media: Incidence and Predisposing Factors.

PubMed

Seo, Nieun; Chung, Yong Eun; Lim, Joon Seok; Song, Mi Kyung; Kim, Myeong-Jin; Kim, Ki Whang

2017-09-01

Bowel angioedema is an acute adverse reaction to iodinated contrast media (CM) that involves the gastrointestinal tract. We aimed to investigate the incidence and predisposing factors of iodinated CM-associated bowel angioedema during computed tomography (CT) examinations. This study was approved by our institutional review board, and informed consent was waived due to its retrospective design. From July 2013 to July 2015, adult patients with a history of adverse reactions to iodinated CM during CT (group A, n = 427) and patients without adverse reactions matched for age and sex with the propensity-score matching method (group B, n = 427) were studied. Contrast media-associated bowel angioedema was determined when bowel wall thickness increased after contrast enhancement compared with the precontrast scan. Potential predisposing factors including patient demographics, symptoms and time of adverse reactions, and CM-related factors were compared between patients with and without angioedema in group A. In addition, the incidence of bowel angioedema was compared between groups A and B. The incidence of CM-associated bowel angioedema in group A was 3.3% (14/427) in the per-patient analysis and 2.6% (15/578) in the per-examination analysis. The CM-associated bowel angioedema involved the distal duodenum and/or proximal jejunum and showed long-segmental circumferential bowel wall thickening on CT. None of the studied predisposing factors was different between patients with and without bowel angioedema (P > 0.05). The incidence of CM-associated bowel angioedema in group B was 1.9% (8/427) and 1.7% (8/458) for per-patient and per-examination analyses, respectively, and these rates were not significantly different between groups A and B (P = 0.346 and P = 0.370, respectively). The incidence of CM-associated bowel angioedema during CT was 1.7% to 3.3%, and none of the studied predisposing factors was associated with bowel angioedema.

Differential Responses of Cecal Microbiota to Fishmeal, Eimeria and Clostridium perfringens in a Necrotic Enteritis Challenge Model in Chickens

PubMed Central

Rodgers, Nicholas; Swick, Robert A.; Moore, Robert J.

2014-01-01

Clostridium perfringens causes enteric diseases in animals and humans. In poultry, avian-specific C. perfringens strains cause necrotic enteritis, an economically significant poultry disease that costs the global industry over $2 billion annually in losses and control measures. With removal of antibiotic growth promoters in some countries this disease appears to be on the rise. In experimental conditions used to study disease pathogenesis and potential control measures, reproduction of the disease relies on the use of predisposing factors such as Eimeria infection and the use of high protein diets, indicating complex mechanisms involved in the onset of necrotic enteritis. The mechanisms by which the predisposing factors contribute to disease progression are not well understood but it has been suggested that they may cause perturbations in the microbiota within the gastrointestinal tract. We inspected changes in cecal microbiota and short chain fatty acids (SCFA) induced by Eimeria and fishmeal, in birds challenged or not challenged with C. perfringens. C. perfringens challenge in the absence of predisposing factors did not cause significant changes in either the alpha or beta diversity of the microbiota nor in concentrations of SCFA. Moreover, there was no C. perfringens detected in the cecal microbiota 2 days post-challenge without the presence of predisposing factors. In contrast, both fishmeal and Eimeria caused significant changes in microbiota, seen in both alpha and beta diversity and also enabled C. perfringens to establish itself post challenge. Eimeria had its strongest influence on intestinal microbiota and SCFA when combined with fishmeal. Out of 6 SCFAs measured, including butyric acid, none were significantly influenced by C. perfringens, but their levels were strongly modified following the use of both predisposing factors. There was little overlap in the changes caused following Eimeria and fishmeal treatments, possibly indicating multiple routes for progressing towards clinical symptoms of necrotic enteritis. PMID:25167074

A Novel Animal Model for Investigating the Neural Basis of Focal Dystonia

DTIC Science & Technology

2017-09-01

as the predisposing condition and dry eye as an environmental trigger to model blepharospasm in rodents. This reporting year we demonstrated that 7...benign essential blepharospasm, dry eye , motor plasticity, basal ganglia, deep brain stimulation, eyelids, blinking 16. SECURITY CLASSIFICATION OF: 17...basal ganglia create the predisposing condition and that  eye   irritation from  dry   eye   is the envi‐ ronmental trigger.  Our demonstration that

Isolated torsion of fallopian tube during pregnancy; report of two cases.

PubMed

Yalcin, O T; Hassa, H; Zeytinoglu, S; Isiksoy, S

1997-08-01

Isolated torsion of fallopian tube is very uncommon during pregnancy. Predisposing factors for torsion are hydrosalpinx, prior tubal operation, pelvic congestion, ovarian and paraovarian masses and trauma. Although the most important clinical symptom is abdominal pain in lower quadrants, the diagnosis is usually established during the operation performed for acute abdomen and salpingectomy is almost always necessary. Two cases of torsion of fallopian tube during pregnancy, one with hydrosalpinx, the other with paratubal cyst are presented and symptoms and predisposing factors are discussed.

Pathogenesis of NEC: Role of the Innate and Adaptive Immune Response

PubMed Central

Denning, Timothy L.; Bhatia, Amina M.; Kane, Andrea F.; Patel, Ravi M.; Denning, Patricia L.

2017-01-01

Necrotizing enterocolitis (NEC) is a devastating disease in premature infants with high case fatality and significant morbidity among survivors. Immaturity of intestinal host defenses predisposes the premature infant gut to injury. An abnormal bacterial colonization pattern with a deficiency of commensal bacteria may lead to a further breakdown of these host defense mechanisms, predisposing the infant to NEC. Here, we review the role of the innate and adaptive immune system in the pathophysiology of NEC. PMID:27940091

Why we cannot conclude that sexual orientation is primarily a biological phenomenon.

PubMed

Byne, W

1997-01-01

While all mental phenomena must have an ultimate biological substrate, the precise contribution of biological factors to the development of sexual orientation remains to be elucidated. Does biology merely provide the slate of neural circuitry upon which sexual orientation is inscribed by experience? Do biological factors directly wire the brain so that it will support a particular orientation? Or do biological factors influence sexual orientation only indirectly, perhaps by influencing personality variables that in turn influence how one interacts with and shapes the environment as it contributes to the social relationships and experiences that shape sexual orientation as it emerges developmentally? Recent neurostructural and genetic linkage evidence pertaining to sexual orientation must be viewed tentatively until it has been adequately corroborated and integrated with psychological and cultural models. Moreover, even a reliable and robust correlation between a biological marker and sexual orientation would be equally compatible with the second and third possibilities delineated above. Yet if the third possibility more closely approximates reality, the search for predisposing biological factors will result in incomplete and misleading findings until their interactions with environmental factors are taken into account and controlled for in adequate longitudinal studies.

Hypoglycemia in the preterm neonate: etiopathogenesis, diagnosis, management and long-term outcomes

PubMed Central

Sharma, Anudeepa; Davis, Ajuah

2017-01-01

Glucose, like oxygen, is of fundamental importance for any living being and it is the major energy source for the fetus and the neonate during gestation. The placenta ensures a steady supply of glucose to the fetus, while birth marks a sudden change in substrate delivery and a major change in metabolism. Hypoglycemia is one of the most common pathologies encountered in the neonatal intensive care unit and affects a wide range of neonates. Preterm, small for gestational age (GA) and intra-uterine growth restricted neonates are especially vulnerable due to their lack of metabolic reserves and associated co-morbidities. Nearly 30–60% of these high-risk infants are hypoglycemic and require immediate intervention. Preterm neonates are uniquely predisposed to developing hypoglycemia and its associated complications due to their limited glycogen and fat stores, inability to generate new glucose using gluconeogenesis pathways, have higher metabolic demands due to a relatively larger brain size, and are unable to mount a counter-regulatory response to hypoglycemia. In this review we will discuss the epidemiology; pathophysiology; clinical presentation; management and neurodevelopmental outcomes in affected infants and summarize evidence to develop a rational and scientific approach to this common problem. PMID:29184814

Neural reward and punishment sensitivity in cigarette smokers.

PubMed

Potts, Geoffrey F; Bloom, Erika L; Evans, David E; Drobes, David J

2014-11-01

Nicotine addiction remains a major public health problem but the neural substrates of addictive behavior remain unknown. One characteristic of smoking behavior is impulsive choice, selecting the immediate reward of smoking despite the potential long-term negative consequences. This suggests that drug users, including cigarette smokers, may be more sensitive to rewards and less sensitive to punishment. We used event-related potentials (ERPs) to test the hypothesis that smokers are more responsive to reward signals and less responsive to punishment, potentially predisposing them to risky behavior. We conducted two experiments, one using a reward prediction design to elicit a Medial Frontal Negativity (MFN) and one using a reward- and punishment-motivated flanker task to elicit an Error Related Negativity (ERN), ERP components thought to index activity in the cortical projection of the dopaminergic reward system. The smokers had a greater MFN response to unpredicted rewards, and non-smokers, but not smokers, had a larger ERN on punishment motivated trials indicating that smokers are more reward sensitive and less punishment sensitive than nonsmokers, overestimating the appetitive value and underestimating aversive outcomes of stimuli and actions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Evaluation of methods for characterizing surface topography of models for high Reynolds number wind-tunnels

NASA Technical Reports Server (NTRS)

Teague, E. C.; Vorburger, T. V.; Scire, F. E.; Baker, S. M.; Jensen, S. W.; Gloss, B. B.; Trahan, C.

1982-01-01

Current work by the National Bureau of Standards at the NASA National Transonic Facility (NTF) to evaluate the performance of stylus instruments for determining the topography of models under investigation is described along with instrumentation for characterization of the surface microtopography. Potential areas of surface effects are reviewed, and the need for finer surfaced models for the NTF high Reynolds number flows is stressed. Current stylus instruments have a radii as large as 25 microns, and three models with surface finishes of 4-6, 8-10, and 12-15 micro-in. rms surface finishes were fabricated for tests with a stylus with a tip radius of 1 micron and a 50 mg force. Work involving three-dimensional stylus profilometry is discussed in terms of stylus displacement being converted to digital signals, and the design of a light scattering instrument capable of measuring the surface finish on curved objects is presented.

Optical fabrication and testing; Proceedings of the Meeting, Singapore, Oct. 22-27, 1990

NASA Astrophysics Data System (ADS)

Lorenzen, Manfred; Campbell, Duncan R.; Johnson, Craig W.

1991-03-01

Various papers on optical fabrication and testing are presented. Individual topics addressed include: interferometry with laser diodes, new methods for economic production of prisms and lenses, interferometer accuracy and precision, optical testing with wavelength scanning interferometer, digital Talbot interferometer, high-sensitivity interferometric technique for strain measurements, absolute interferometric testing of spherical surfaces, contouring using gratings created on an LCD panel, three-dimensional inspection using laser-based dynamic fringe projection, noncontact optical microtopography, laser scan microscope and infrared laser scan microscope, photon scanning tunneling microscopy. Also discussed are: combination-matching problems in the layout design of minilaser rangefinder, design and testing of a cube-corner array for laser ranging, mode and far-field pattern of diode laser-phased arrays, new glasses for optics and optoelectronics, optical properties of Li-doped ZnO films, application and machining of Zerodur for optical purposes, finish machining of optical components in mass production.

Long-term observations of bottom conditions and sediment movement on the Atlantic continental shelf; time-lapse photography from instrumented tripod

USGS Publications Warehouse

Butman, Bradford; Bryden, Cynthia G.; Pfirman, Stephanie L.; Strahle, William J.; Noble, Marlene A.

1984-01-01

An instrument system that measures bottom current, temperature, light transmission, and pressure, and that photographs the bottom at 2- to 6-hour intervals has been developed to study sediment transport on the Atlantic Continental Shelf. Instruments have been deployed extensively along the United States East Coast Continental Shelf for periods of from 2 to 6 months to study the frequency, direction, and rate of bottom sediment movement, and the processes causing movement. The time-lapse photographs are used to (1) characterize the bottom benthic community and surface microtopography; (2) monitor changes in the bottom topography and near-bottom water column caused by currents and storms (for example, ripple generation and migration, sediment resuspension); and (3) monitor seasonal changes in the bottom benthic community and qualitative effects of this community on the bottom sediments.

Research of Adhesion Bonds Between Gas-Thermal Coating and Pre-Modified Base

NASA Astrophysics Data System (ADS)

Kovalevskaya, Z.; Zaitsev, K.; Klimenov, V.

2016-08-01

Nature of adhesive bonds between gas-thermal nickel alloy coating and carbon steel base was examined using laser profilometry, optical metallography, transmission and scanning electron microscopy. The steel surface was plastically pre-deformed by an ultrasonic tool. Proved that ultrasound pre-treatment modifies the steel surface. Increase of dislocation density and formation of sub micro-structure are base elements of surface modification. While using high-speed gas-flame, plasma and detonation modes of coatings, surface activation occurs and durable adhesion is formed. Ultrasonic pre-treatment of base material is effective when sprayed particles and base material interact through physical-chemical bond formation. Before applying high-speed gas flame and plasma sprayed coatings, authors recommend ultrasonic pretreatment, which creates periodic wavy topography with a stroke of 250 microns on the steel surface. Before applying detonation sprayed coatings, authors recommend ultrasound pretreatment that create modified surface with a uniform micro-topography.

Agrogenic degradation of soils in Krasnoyarsk forest-steppe

NASA Astrophysics Data System (ADS)

Shpedt, A. A.; Trubnikov, Yu. N.; Zharinova, N. Yu.

2017-10-01

Agrogenic degradation of soils in Krasnoyarsk forest-steppe was investigated. Paleocryogenic microtopography of microlows and microhighs in this area predetermined the formation of paragenetic soil series and variegated soil cover. Specific paleogeographic conditions, thin humus horizons and soil profiles, and long-term agricultural use of the land resulted in the formation of soils unstable to degradation processes and subjected to active wind and water erosion. Intensive mechanical soil disturbances during tillage and long-term incorporation of the underlying Late Pleistocene (Sartan) calcareous silty and clay loams into the upper soil horizons during tillage adversely affected the soil properties. We determined the contents of total and labile humus and easily decomposable organic matter and evaluated the degree of soil exhaustion. It was concluded that in the case of ignorance of the norms of land use and soil conservation practices, intense soil degradation would continue leading to complete destruction of the soil cover within large areas.

Preparation, characterization and antibacterial activity of oxidized κ-carrageenan.

PubMed

Zhu, Mingjin; Ge, Liming; Lyu, Yongbo; Zi, Yaxin; Li, Xinying; Li, Defu; Mu, Changdao

2017-10-15

The oxidized κ-carrageenans with different oxidation levels were prepared through the hydrogen peroxide and copper sulfate redox system. The oxidation level of oxidized κ-carrageenan was successfully controlled by adjusting the dosage of hydrogen peroxide. The results showed that the microtopography of oxidized κ-carrageenan changed from rough granules to smooth flakes, mainly resulting from the easily melting property of oxidized κ-carrageenan induced by introduced carboxyl and aldehyde groups. Especially, the antibacterial activity of oxidized κ-carrageenans against Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) was systematically investigated. The results showed that the oxidized κ-carrageenan could damage the bacterial cell wall and cytoplasmic membrane and suppress the growth of both Gram-positive and Gram-negative bacteria. The oxidized κ-carrageenan possessed broad-spectrum antibacterial activity, which may be used as a new antibacterial agent. Copyright © 2017 Elsevier Ltd. All rights reserved.

Measurement of surface microtopography

NASA Technical Reports Server (NTRS)

Wall, S. D.; Farr, T. G.; Muller, J.-P.; Lewis, P.; Leberl, F. W.

1991-01-01

Acquisition of ground truth data for use in microwave interaction modeling requires measurement of surface roughness sampled at intervals comparable to a fraction of the microwave wavelength and extensive enough to adequately represent the statistics of a surface unit. Sub-centimetric measurement accuracy is thus required over large areas, and existing techniques are usually inadequate. A technique is discussed for acquiring the necessary photogrammetric data using twin film cameras mounted on a helicopter. In an attempt to eliminate tedious data reduction, an automated technique was applied to the helicopter photographs, and results were compared to those produced by conventional stereogrammetry. Derived root-mean-square (RMS) roughness for the same stereo-pair was 7.5 cm for the automated technique versus 6.5 cm for the manual method. The principal source of error is probably due to vegetation in the scene, which affects the automated technique but is ignored by a human operator.

Single Crystals Grown Under Unconstrained Conditions

NASA Astrophysics Data System (ADS)

Sunagawa, Ichiro

Based on detailed investigations on morphology (evolution and variation in external forms), surface microtopography of crystal faces (spirals and etch figures), internal morphology (growth sectors, growth banding and associated impurity partitioning) and perfection (dislocations and other lattice defects) in single crystals, we can deduce how and by what mechanism the crystal grew and experienced fluctuation in growth parameters through its growth and post-growth history under unconstrained condition. The information is useful not only in finding appropriate way to growing highly perfect and homogeneous single crystals, but also in deciphering letters sent from the depth of the Earth and the Space. It is also useful in discriminating synthetic from natural gemstones. In this chapter, available methods to obtain molecular information are briefly summarized, and actual examples to demonstrate the importance of this type of investigations are selected from both natural minerals (diamond, quartz, hematite, corundum, beryl, phlogopite) and synthetic crystals (SiC, diamond, corundum, beryl).

Winter Waterbird Community Composition and Use at Created Wetlands in West Virginia, USA

PubMed Central

Peters, Michael L.

2017-01-01

Information on nonbreeding waterbirds using created wetlands in the Central Appalachian region of the United States is limited. We compared waterbird communities of two managed wetlands, created in 2013 and 2001, in West Virginia. We observed 27 species of waterbirds. Species richness and diversity were generally similar between the wetlands, but species composition and use differed. Branta canadensis (Canada Geese), Anas strepera (Gadwall), Bucephala albeola (Buffleheads), Aythya affinis (Lesser Scaup), and Aythya collaris (Ring-Necked Ducks) used the older wetland most frequently. Disparities in species use were the highest in March. The older wetland differed from the younger in supporting species such as diving ducks, possibly due to differences in size, vegetation, water depth, and microtopography. However, the ability to provide habitat for waterbirds during the winter was determined to be comparable between wetlands, despite their age difference. PMID:28386513

A novel approach to determine the efficacy of patterned surfaces for biofouling control in relation to its microfluidic environment.

PubMed

Halder, Partha; Nasabi, Mahyar; Lopez, Francisco Javier Tovar; Jayasuriya, Niranjali; Bhattacharya, Satinath; Deighton, Margaret; Mitchell, Arnan; Bhuiyan, Muhammed Ali

2013-01-01

Biofouling, the unwanted growth of sessile microorganisms on submerged surfaces, presents a serious problem for underwater structures. While biofouling can be controlled to various degrees with different microstructure-based patterned surfaces, understanding of the underlying mechanism is still imprecise. Researchers have long speculated that microtopographies might influence near-surface microfluidic conditions, thus microhydrodynamically preventing the settlement of microorganisms. It is therefore very important to identify the microfluidic environment developed on patterned surfaces and its relation with the antifouling behaviour of those surfaces. This study considered the wall shear stress distribution pattern as a significant aspect of this microfluidic environment. In this study, patterned surfaces with microwell arrays were assessed experimentally with a real-time biofilm development monitoring system using a novel microchannel-based flow cell reactor. Finally, computational fluid dynamics simulations were carried out to show how the microfluidic conditions were affecting the initial settlement of microorganisms.

Optical fabrication and testing; Proceedings of the Meeting, Singapore, Oct. 22-27, 1990

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

Lorenzen, M.; Campbell, D.R.; Johnson, C.W.

1991-01-01

Various papers on optical fabrication and testing are presented. Individual topics addressed include: interferometry with laser diodes, new methods for economic production of prisms and lenses, interferometer accuracy and precision, optical testing with wavelength scanning interferometer, digital Talbot interferometer, high-sensitivity interferometric technique for strain measurements, absolute interferometric testing of spherical surfaces, contouring using gratings created on an LCD panel, three-dimensional inspection using laser-based dynamic fringe projection, noncontact optical microtopography, laser scan microscope and infrared laser scan microscope, photon scanning tunneling microscopy. Also discussed are: combination-matching problems in the layout design of minilaser rangefinder, design and testing of a cube-corner arraymore » for laser ranging, mode and far-field pattern of diode laser-phased arrays, new glasses for optics and optoelectronics, optical properties of Li-doped ZnO films, application and machining of Zerodur for optical purposes, finish machining of optical components in mass production.« less

A common variant of CDKN2A (p16) predisposes to breast cancer

PubMed Central

Debniak, T; Gorski, B; Huzarski, T; Byrski, T; Cybulski, C; Mackiewicz, A; Gozdecka-Grodecka, S; Gronwald, J; Kowalska, E; Haus, O; Grzybowska, E; Stawicka, M; Swiec, M; Urbanski, K; Niepsuj, S; Wasko, B; Gozdz, S; Wandzel, P; Szczylik, C; Surdyka, D; Rozmiarek, A; Zambrano, O; Posmyk, M; Narod, S; Lubinski, J

2005-01-01

Background: A common missense variant of the CDKN2A gene (A148T) predisposes to malignant melanoma in Poland. An association between malignant melanoma and breast cancer has been reported in several families with CDKN2A mutations, Objective: To determine whether this variant also predisposes to breast cancer. Methods: Genotyping was undertaken in 4209 cases of breast cancer, unselected for family history, from 18 hospitals throughout Poland and in 3000 controls. Results: The odds ratio (OR) associated with the CDKN2A allele for women diagnosed with breast cancer before the age of 50 was 1.5 (p = 0.002) and after age 50 it was 1.3 (p = 0.2). The effect was particularly strong for patients diagnosed at or before the age of 30 (OR = 3.8; p = 0.0002). Conclusions: CDKN2A appears to be a low penetrance breast cancer susceptibility gene in Poland. The association should be confirmed in other populations. PMID:15879498

Clinical outcome in 94 cases of dermal haemangiosarcoma in dogs treated with surgical excision: 1993-2007*.

PubMed

Szivek, A; Burns, R E; Gericota, B; Affolter, V K; Kent, M S; Rodriguez, C O; Skorupski, K A

2012-03-01

Canine dermal haemangiosarcoma (HSA) is believed to have a better prognosis compared to HSA in other organs, but outcome has only been reported in a small number of dogs. The purpose of this study was to assess outcome and prognostic factors in a larger cohort of dogs with dermal HSA. Clinical data was collected retrospectively for 94 dogs and histopathology was reviewed in 53 dogs. Median overall survival time was 987 days. Dogs of predisposed breed with ventral location and histologic solar changes had longer survivals. Loco-regional recurrence occurred in 72/94 (77%) dogs. Predisposed breeds with ventral location and multiple masses were more likely to develop recurrence. Non-predisposed breeds with invasive tumours were more likely to develop metastasis. Results suggest that dogs with solar-induced dermal HSA may have high recurrence rates, but prolonged survivals. Dogs with non-solar tumours may be at increased risk for metastasis and shorter survival. © 2011 Blackwell Publishing Ltd.

Ocular infections caused by Scedosporium apiospermum: A case series

PubMed Central

Ramakrishnan, Seema; Mandlik, Kunal; Sathe, Tejashree Sanket; Gubert, Joseph; Krishnan, Thiruvengada; Baskaran, Prabu

2018-01-01

The aim of our retrospective study is to report a case series of ocular infections caused by a rare fungus, Scedosporium apiospermum, in a South Indian population. Thirteen cases of culture-positive S. apiospermum infections diagnosed between January 2011 and March 2016 were included in this study. The parameters evaluated were predisposing factors, treatment and final clinical outcome. The most common mode of presentation was keratitis (84.6%) followed by sclerokeratitis (15.3%). The predisposing factors involved were unspecified foreign body injury (30.7%), organic matter injury (15.3%), uncontrolled diabetes (7.6%), and recent manual small-incision cataract surgery (7.6%). Five cases (38.46%) had no predisposing factor. Of the 11 keratitis cases, nine (69.2%) responded well to combination medical therapy while one case (7.6%) required therapeutic keratoplasty. One case was lost to follow-up. Both cases which presented with sclerokeratitis showed no response to medico-surgical treatment progressing to panophthalmitis and evisceration. PMID:29283143

Perceptions of predisposing, enabling, and reinforcing factors influencing the use of a continuity of care document in special needs PLWH.

PubMed

Odlum, Michelle; Gordon, Peter; Camhi, Eli; Schnall, Rebecca; Teixeira, Paul; Bakken, Suzanne

2012-11-01

The provision of personal health information through electronic personal health management tools (EPHMT) has the potential to improve health outcomes. However, little is known about factors that affect EPHMT use in special needs people living with HIV/AIDS (PLWH). The purpose of this study was to describe PLWH perceptions of predisposing, enabling, and reinforcing factors affecting use of one type of EPHMT, a continuity of care document (CCD). Data were collected through focus groups and qualitative interviews with PLWH (n=35), health care providers (N=19) and care site managers (N=5). All participant types identified predisposing barriers to CCD use including literacy, privacy, and technology access and enabling factors to promote CCD use including user support and password simplicity. People living with HIV/AIDS also identified reinforcing factors for recurring CCD use including emergent situations and reducing test redundancy. Results inform methods to promote use of the CCD and other EPHMT by special needs PLWH.

Extremely high frequency of autoimmune-predisposing alleles in medieval specimens*

PubMed Central

Witas, H.W.; Jędrychowska-Dańska, K.; Zawicki, P.

2007-01-01

The precise etiology and reasons for the increase in incidence of autoimmune disorders still remain unclear, and although both genetic and environmental factors have been proven to shape individual predisposition, it is not known which of the factors, if not both, is responsible for the boom observed during the last decades. In order to establish whether a higher frequency of autoimmune-predisposing alleles may explain this increase we took advantage of ancient DNA methodology to establish the genetic predisposition, conferred by cytotoxic T lymphocyte associated antigen-4 (CTLA4) +49A/G and human leukocyte antigens (HLA) DQB157, in population inhabiting Poland in the Middle Ages. After successful typing of 42 individuals from a 12th~14th’s century archeological burial site, we found that frequencies of the predisposing alleles in the medieval population were higher than they are at present, suggesting thus that the recently observed incidence increase results most probably from factors of other than genetic nature. PMID:17610332

Syndromes with salivary dysfunction predispose to tooth wear: Case reports of congenital dysfunction of major salivary glands, Prader-Willi, congenital rubella, and Sjögren's syndromes.

PubMed

Young, W; Khan, F; Brandt, R; Savage, N; Razek, A A; Huang, Q

2001-07-01

Four cases-of congenital dysfunction of the major salivary glands as well as of Prader-Willi, congenital rubella, and Sjögren's syndromes-were identified in a series of 500 patients referred for excessive tooth wear. Although there was evidence of consumption of highly acidic drinks, some occlusal parafunction, and unacceptable toothbrushing habits, salivary dysfunction was the salient factor predisposing a patient to tooth wear in these syndromal cases. The 500 subjects have been characterized either as having medical conditions and medications that predispose them to xerostomia or lifestyles in which workplace- and sports-related dehydration lead to reduced salivary flow. Normal salivation, by buffering capacity, clearance by swallowing, pellicle formation, and capacity for remineralization of demineralized enamel, protects the teeth from extrinsic and intrinsic acids that initiate dental erosion. Thus, the syndromes, unrelated in many respects, underline the importance of normal salivation in the protection of teeth against tooth wear by erosion, attrition, and abrasion.

Urinary tract infection associated with conditions causing urinary tract obstruction and stasis, excluding urolithiasis and neuropathic bladder.

PubMed

Heyns, C F

2012-02-01

The aim of this study was to examine urinary tract infection (UTI) associated with conditions causing urinary tract obstruction and stasis, excluding urolithiasis and neuropathic bladder dysfunction. An electronic literature search was performed using the key words urinary tract infection (UTI), benign prostatic hyperplasia (BPH), hydronephrosis, obstruction, reflux, diverticulum, urethra, and stricture. In total, 520 abstracts were reviewed, 210 articles were studied in detail, and 36 were included as references. It is one of the axioms of Urological practice that urinary tract obstruction and stasis predispose to UTI. Experimental studies indicate that, whereas transurethral inoculates of bacteria are rapidly eliminated from the normal bladder, urethral obstruction leads to cystitis, pyelonephritis, and bacteremia. BPH is, next to urolithiasis, the most common cause of urinary tract obstruction predisposing to UTI. Urethral stricture remains a common cause of UTI in many parts of the world. Urinary stasis in diverticula of the urethra or bladder predisposes to UTI. Experimental studies have shown that, whereas the normal kidney is relatively resistant to infection by organisms injected intravenously, ureteric obstruction predisposes to pyelonephritis. It also causes renal dysfunction which impairs the excretion of antibiotics in the urine, making eradication of bacteria difficult. In patients with UTI and urinary tract obstruction, targeted antibiotic treatment according to urine culture should be complemented with urgent drainage (bladder catheterization, percutaneous nephrostomy or ureteric stenting) followed by definitive surgery to remove the cause of obstruction or stasis once infection is under control.

[Cognitive and emotional alterations in chronic insomnia].

PubMed

Medrano-Martínez, Pablo; Ramos-Platón, María J

2016-02-16

Little is known about the cognitive and emotional alterations associated with chronic insomnia. After reviewing the aetiology and pathophysiology of chronic insomnia, taking into account the patient's vulnerability and its inheritability, this study reports on the knowledge currently held about the cognitive deficits and emotional alterations observed in patients with chronic insomnia. Most aetiological models include factors that predispose an individual to insomnia, as well as precipitating and maintaining it. Predisposing factors can be of a biological or psychosocial nature. One predisposing factor that plays an important role is the vulnerability to insomnia, which is related to a non-adaptive way of coping with stress (focused on the emotion rather than on the problem) and the internalisation of negative emotions, which favours a state of physiological, cognitive and emotional hyperactivation that disrupts sleep and may lead to insomnia. This vulnerability is largely hereditary. Two phenotypes, based on the objective duration of sleep, have been described, the difference between them being the severity of the disorder. Insomniacs with an objective sleep time below six hours present significant cognitive deficits. These become manifest in tasks that require a large number of cognitive resources, complex attention tasks, changes in the focus of attention, the process of consolidation of memory during sleep, and working memory. These data suggest the existence of a prefrontal dysfunction. Comorbidity between insomnia and anxiety-depression is high. The anxiety-depression triggered by the internalisation of emotions predisposes the individual to insomnia and this, in turn, intensifies the depression.

[Prevalence and spectrum of diseases that predispose to sudden cardiac death in Mexican children: a sample obtained from The Federico Gomez Children's Hospital of Mexico].

PubMed

Cano-Hernández, Karla Sarahí; Nava-Townsend, Santiago; Sánchez-Boiso, Adriana; Sánchez-Urbina, Rocío; Contreras-Ramos, Alejandra; Erdmenger-Orellana, Julio Roberto; Tamayo-Espinosa, Tania; Becerra-Becerra, Rosario; Segura-Stanford, Begoña; Solano-Fiesco, Liborio; Balderrábano-Saucedo, Norma Alicia

2017-09-22

To determine the prevalence and spectrum of diseases that predispose to sudden cardiac death in Mexican children, and to identify the main early signs and symptoms that can enable the health personnel to suspect these diseases and to refer the patients to a tertiary hospital in a timely manner. Incidence, prevalence, and period prevalence, as well as early symptoms, clinical data, and follow-up were recorded on all children found with diseases that predispose to sudden cardiac death in The Children's Hospital of Mexico. The study included 59 patients, with a mean age of 8 ± 5 years old, with 40 cardiomyopathies, and 19 with inherited arrhythmogenic diseases. The period prevalence was 9.5/1,000 patients/year. The most common early symptoms were dyspnoea, palpitations, and syncope. A Mendelian inheritance pattern was found in 9 cases. Three patients died of sudden cardiac death during the period of the study. Diseases that predispose to sudden cardiac death in children are not very well known by the general medical community. Every child with dyspnoea, palpitations and/or syncope, should be referred for the intensive search of these diseases. A complete cardiological evaluation in all members of the family is indicated. Copyright © 2017 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

Predator-prey pursuit-evasion games in structurally complex environments.

PubMed

Morice, Sylvie; Pincebourde, Sylvain; Darboux, Frédéric; Kaiser, Wilfried; Casas, Jérôme

2013-11-01

Pursuit and evasion behaviors in many predator-prey encounters occur in a geometrically structured environment. The physical structures in the environment impose strong constraints on the perception and behavioral responses of both antagonists. Nevertheless, no experimental or theoretical study has tackled the issue of quantifying the role of the habitat's architecture on the joint trajectories during a predator-prey encounter. In this study, we report the influence of microtopography of forest leaf litter on the pursuit-evasion trajectories of wolf spiders Pardosa sp. attacking the wood cricket Nemobius sylvestris. Fourteen intact leaf litter samples of 1 m × 0.5 m were extracted from an oak-beech forest floor in summer and winter, with later samples having the most recently fallen leaves. Elevation was mapped at a spatial resolution of 0.5 mm using a laser scanner. Litter structuring patterns were identified by height transects and experimental semi-variograms. Detailed analysis of all visible leaf-fragments of one sample enabled us to relate the observed statistical patterns to the underlying geometry of individual elements. Video recording of pursuit-evasion sequences in arenas with flat paper or leaf litter enabled us to estimate attack and fleeing distances as a function of substrate. The compaction index, the length of contiguous flat surfaces, and the experimental variograms showed that the leaf litter was smoother in summer than in winter. Thus, weathering as well as biotic activities compacted and flattened the litter over time. We found good agreement between the size of the structuring unit of leaf litter and the distance over which attack and escape behaviors both were initiated (both ∼3 cm). There was a four-fold topographical effect on pursuit-escape sequences; compared with a flat surface, leaf litter (1) greatly reduced the likelihood of launching a pursuit, (2) reduced pursuit and escape distances by half, (3) put prey and predator on par in terms of pursuit and escape distances, and (4) reduced the likelihood of secondary pursuits, after initial escape of the prey, to nearly zero. Thus, geometry of the habitat strongly modulates the rules of pursuit-evasion in predator-prey interactions in the wild.

Past and Future Stability of Deep Peatland Carbon Stocks: Assessing the Nature and Fate of Carbon in a Northern Minnesota Ombrotrophic Peatland (Invited)

NASA Astrophysics Data System (ADS)

Hanson, P. J.; Chanton, J.; Iversen, C. M.; McFarlane, K. J.; Tfaily, M. M.; Xu, X.

2013-12-01

An ombrotrophic Picea-Sphagnum peatland located on the Marcell Experimental Forest in northern Minnesota is being prepared for experimental manipulations to evaluate carbon cycle responses to warming and elevated CO2. Pretreatment characterization of the peatland, which has a mean peat depth of ~3 meters, showed that belowground carbon (C) stocks were greater than 2200 MgC ha-1. This is easily 10× greater than the combined above- and belowground C stocks found in typical eastern deciduous forests. Carbon has accumulated under saturated, cool to cold conditions since the last glaciers receded some 10,000 years ago. Mean bulk-14C assessments show a modern C signature and decadal turnover time for peat in the raised hummock topography, as well as in the oxic acrotelm layer which extends to a depth of 30-cm below hollow microtopography. Deeper peat layers (below 30-cm depth) have C ages ranging from 1000- to 2000 years for relatively shallow layers, to between 7000 and 8000 years at 2.5 m depth. In contrast, the 14C signatures of dissolved inorganic C (DIC) and dissolved organic C (DOC), which reflect the substrates consumed by microbes, were relatively modern, even at depths of up to 2 meters. The modern 14C signatures indicate that microbial respiration at depth is fueled by surface inputs of DOC. Furthermore, the contrast in δ14C between solid-phase peat and DOC at deeper peat depths will allow researchers to quantify the effects of warming and elevated CO2 on the fate of peat stored in this ombrotrophic peatland for millennia. It is unclear whether C accumulation in peatlands will continue under warmer conditions associated with atmospheric and climatic change. Modeled projections for net peat C turnover throughout the peat profile will be discussed in the context of the planned warming manipulations. Initial hypotheses suggest that peat accumulation may be sustained for low levels of warming, but shift to a pattern of net carbon release as both CO2 and CH4 for warmer future climates.

Treatment effects on performance of N-fixing lichens in disturbed crusts of the Colorado Plateau

USGS Publications Warehouse

Davidson, Diane W.; Bowker, Mathew; George, Dylan; Phillips, Susan L.; Belnap, Jayne

2002-01-01

Biological soil crusts arrest soil erosion and supply nitrogen to arid ecosystems. To understand their recovery from disturbance, we studied performances of Collema spp. lichens relative to four experimental treatments plus microtopography of soil pedicels, oriented north-northwest to south-southeast in crusts. At sites in Needles (NDLS) and Island in the Sky (ISKY) districts of Canyonlands National Park, lichens were transplanted to NNW, SSE, ENE, WSW, and TOP pedicel faces and exposed to a full-factorial, randomized block experiment with four treatments: nutrient addition (P and K), soil stabilization with polyacrylamide resin (PAM), added cyanobacterial fiber, and biweekly watering.After 14.5 mo (NDLS) and 24 mo (ISKY), both visual rankings of lichen condition and measures of chlorophyll fluorescence were generally higher at ISKY than on more fertile but less stable soils at NDLS. On ENE and NNW pedicel faces, both these values and nitrogenase activity (NDLS only) exceeded corresponding values on WSW and SSE faces. Treatment effects were site specific and largely negative at NDLS; both nutrient and cyanobacterial addition led to poorer lichen condition, and added nutrients led to reduced fluorescence. Responses to nutrients may have been mediated partly by disturbance of unstable soils and by competition with cyanobacteria.In a separate experiment investigating recruitment responses to adding fungal spores or Nostoc cells, rates of Collema establishment responded significantly to the former but not the latter. Low establishment overall suggests that natural recruitment may occur mainly from iscidia or thallus fragments, not spores.Measured simultaneously on artificial soil pedicels at NDLS and ISKY, both deposition and erosion declined at NDLS across the four pedicel microaspects as: WSW > SSE > NNW > ENE (or ENE > NNW), during fall and spring trials. Patterns were similar at ISKY, but WSW ≈ SSE for spring deposition, and deposition did not differ by microaspect in fall. Greater deposition at ISKY, despite higher abundance of cyanobacteria, may be explained by stronger wind velocities.Together, microtopographic differences in erosion, microclimate, and nutrient regimes help explain variable lichen performance, but microtopography influenced lichen performance more consistently than did any treatment. Demonstrated effects of pedicel development in crust recovery concur with prior surveys showing greatest microbial biomass and/or cover on ENE and NNW exposures at various spatial scales.

TiO2 micro-nano-hybrid surface to alleviate biological aging of UV-photofunctionalized titanium

PubMed Central

Iwasa, Fuminori; Tsukimura, Naoki; Sugita, Yoshihiko; Kanuru, Rajita Kodali; Kubo, Katsutoshi; Hasnain, Hafiz; Att, Wael; Ogawa, Takahiro

2011-01-01

Bioactivity and osteoconductivity of titanium degrade over time after surface processing. This time-dependent degradation is substantial and defined as the biological aging of titanium. UV treatment has shown to reactivate the aged surfaces, a process known as photofunctionalization. This study determined whether there is a difference in the behavior of biological aging for titanium with micro-nano-hybrid topography and titanium with microtopography alone, following functionalization. Titanium disks were acid etched to create micropits on the surface. Micro-nano-hybrid surfaces were created by depositioning 300-nm diameter TiO2 nodules onto the micropits using a previously established self-assembly protocol. These disks were stored for 8 weeks in the dark to allow sufficient aging, then treated with UV light for 48 hours. Rat bone marrow–derived osteoblasts were cultured on fresh disks (immediately after UV treatment), 3-day-old disks (disks stored for 3 days after UV treatment), and 7-day- old disks. The rates of cell attachment, spread, proliferation, and levels of alkaline phosphatase activity, and calcium deposition were reduced by 30%–50% on micropit surfaces, depending on the age of the titanium. In contrast, 7-day-old hybrid surfaces maintained equivalent levels of bioactivity compared with the fresh surfaces. Both micropit and micro-nano-hybrid surfaces were superhydrophilic immediately after UV treatment. However, after 7 days, the micro-nano- hybrid surfaces became hydrorepellent, while the micropit surfaces remained hydrophilic. The sustained bioactivity levels of the micro-nano-hybrid surfaces were nullified by treating these surfaces with Cl−anions. A thin TiO2 coating on the micropit surface without the formation of nanonodules did not result in the prevention or alleviation of the time-dependent decrease in biological activity. In conclusion, the micro-nano-hybrid titanium surfaces may slow the rate of time-dependent degradation of titanium bioactivity after UV photofunctionalization compared with titanium surfaces with microtopography alone. This antibiological aging effect was largely regulated by its sustained electropositivity uniquely conferred in TiO2 nanonodules, and was independent of the degree of hydrophilicity. These results demonstrate the potential usefulness of these hybrid surfaces to effectively utilize the benefits of UV photofunctionalization and provide a model to explore the mechanisms underlying antibiological aging properties. PMID:21760728

TiO2 micro-nano-hybrid surface to alleviate biological aging of UV-photofunctionalized titanium.

PubMed

Iwasa, Fuminori; Tsukimura, Naoki; Sugita, Yoshihiko; Kanuru, Rajita Kodali; Kubo, Katsutoshi; Hasnain, Hafiz; Att, Wael; Ogawa, Takahiro

2011-01-01

Bioactivity and osteoconductivity of titanium degrade over time after surface processing. This time-dependent degradation is substantial and defined as the biological aging of titanium. UV treatment has shown to reactivate the aged surfaces, a process known as photofunctionalization. This study determined whether there is a difference in the behavior of biological aging for titanium with micro-nano-hybrid topography and titanium with microtopography alone, following functionalization. Titanium disks were acid etched to create micropits on the surface. Micro-nano-hybrid surfaces were created by depositioning 300-nm diameter TiO(2) nodules onto the micropits using a previously established self-assembly protocol. These disks were stored for 8 weeks in the dark to allow sufficient aging, then treated with UV light for 48 hours. Rat bone marrow-derived osteoblasts were cultured on fresh disks (immediately after UV treatment), 3-day-old disks (disks stored for 3 days after UV treatment), and 7-day- old disks. The rates of cell attachment, spread, proliferation, and levels of alkaline phosphatase activity, and calcium deposition were reduced by 30%-50% on micropit surfaces, depending on the age of the titanium. In contrast, 7-day-old hybrid surfaces maintained equivalent levels of bioactivity compared with the fresh surfaces. Both micropit and micro-nano-hybrid surfaces were superhydrophilic immediately after UV treatment. However, after 7 days, the micro-nano- hybrid surfaces became hydrorepellent, while the micropit surfaces remained hydrophilic. The sustained bioactivity levels of the micro-nano-hybrid surfaces were nullified by treating these surfaces with Cl(-)anions. A thin TiO(2) coating on the micropit surface without the formation of nanonodules did not result in the prevention or alleviation of the time-dependent decrease in biological activity. In conclusion, the micro-nano-hybrid titanium surfaces may slow the rate of time-dependent degradation of titanium bioactivity after UV photofunctionalization compared with titanium surfaces with microtopography alone. This antibiological aging effect was largely regulated by its sustained electropositivity uniquely conferred in TiO(2) nanonodules, and was independent of the degree of hydrophilicity. These results demonstrate the potential usefulness of these hybrid surfaces to effectively utilize the benefits of UV photofunctionalization and provide a model to explore the mechanisms underlying antibiological aging properties.

Historical landscape elements in preserving steppic species - vegetation responses on micro-topography and human disturbances

NASA Astrophysics Data System (ADS)

Deák, Balázs; Valkó, Orsolya; Török, Péter; Tóthmérész, Béla

2017-04-01

Land use changes of past centuries resulted in a considerable loss and isolation of grassland habitats worldwide which also led to a serious loss in ecosystem functions. In intensively used agricultural landscapes remnants of natural flora persisted only in small habitat islands embedded in a hostile matrix, which are inadequate for arable farming or construction. In the steppe zone of Eurasia burial mounds, so-called kurgans, have a great potential to preserve the natural flora and habitats and act as local biodiversity hotspots. Their special micro-topography and historical origin makes kurgans characteristic landscape elements of the steppe region. These features also result in a specific soil development and micro-climate, which makes kurgans especially adequate habitats for several steppe specialist plant species. Furthermore, they are proper objects for studying the effects of present and past human disturbances on the vegetation of semi-natural habitats. Exploration of the main factors driving biodiversity in isolated habitat fragments is crucial for understanding the ecological processes shaping their vegetation and for designing effective strategies for their protection. We surveyed the vegetation of 44 isolated kurgans in East-Hungary and studied the effects of habitat area, slope, recent disturbance, past destruction and the level of woody encroachment on the species richness and cover of grassland specialist and weedy species. We used model selection techniques and linear models for testing relevant factors affecting specialist species in grassland fragments. We found that the biodiversity conservation potential of kurgans is supported by their steep slopes, which provide adequate habitat conditions and micro-climate for steppic specialist plant species. By harbouring several grassland specialist species, kurgans have a great potential for preserving the natural species pool of even considerably altered agricultural landscapes, and can mitigate the negative consequences of landscape-level human disturbances. Our results suggest that specialist species are threatened both by recent disturbances and encroachment of alien woody species, especially black locust. Factors supporting specialist species suppressed weedy species by providing unfavourable environmental conditions and putting them at a competitive disadvantage. We identified that woody encroachment and current disturbances affect the vast majority of kurgans, posing a serious threat to grassland specialist species. Thus, there is an urgent need to integrate active conservation measures into the current passive protection of kurgans.

Inland notches micromorphology

NASA Astrophysics Data System (ADS)

Brook, Anna; Ben-Binyamin, Atzmon; Shtober-Zisu, Nurit

2017-04-01

Inland notches are well known phenomenon in Israel and can be found mostly along the mountainous backbone, developed in hard limestone or dolomite rocks within the Mediterranean climate zone and up to the desert fringe. LiDAR technology presents an opportunity to study the fine scale rock surface within the notch and its texture patterns. De-trending of the LiDAR reconstructed DEM to a local trend, surface roughness, was achieved by fitting a normalized surface to all measured ground points within the roughness neighborhood. Micro-topography plays an important role for modelling geomorphology dynamics, resulting in improved estimates for micro stream lines network and topographic erosion as well as mineral accumulation or deposition. Clearly, dissolution occurs whenever rock and solvent meet; thus water and moisture's crucial role in the decay of carbonate rocks results in texture and roughness variability. Study aims is to generate high resolution normalized DEM models using a terrestrial LiDAR, redefining the texture and roughness within the notch while assessing weathering processes caused by water. Plan curvature is the second derivative of slope taken perpendicular to its direction. It influences convergence and divergence of flow and it emphasizes the ridges and valleys across the surface. Concaved classified areas were tested against all planar curvature areas to distinguish them as unique areas based on their texture co-occurrence measures (GLCM). Overall negative curvature pixels show poor separability, in both TD and JM separation tests, while classes of curvature degree describe a positive trend showing medium and high concavity as unique areas. Study aims to link classified areas as the basic micro infrastructure for water flow, potential runoff flow and further accumulation of minerals. On the other hand, positive values of Plan curvature present the convexity of rock surface to imply diverging flow, thus describing the watershed line within the micro-topography. GLCM texture measure map distinct areas within the notch. Middle section of the notch has uniform texture neighborhood with relatively low mean elevation values (high values for homogeneity and energy). Bottom cavity of notch reveals a more chaotic texture, highlighting the spatial disorder with relatively high mean values. Entropy calculates how random the roughness values are, and as such, high values of this measure, at the cavity's bottom, suggest a potentially rapid erosion or disposition dynamics.

Water storage capacity of the natural river valley - how sedge communities influence it. Case study of Upper Biebrza Basin (Poland) based on ALS and TLS data

NASA Astrophysics Data System (ADS)

Brach, Marcin; Chormański, Jarosław

2014-05-01

The exact determination of water storage capacity in river valley is an important issue for hydrologists, ecologist and flood modellers. In case of natural river valley, the dense and complexity vegetation of the natural ecosystems can influence the proper identification of the water storage. Methods considered to be sufficient in other cases (urbanized, agricultural) may not produce correct results. Sedge communities in natural river valleys form characteristic tussocks, built from the species roots, other organic material and silt or mud. They are formed due to partial flooding during the inundation, so the plants can survive in hard, anaerobic conditions. They can growth even up to 0.5 meters, which is not so visible due to very dense vegetation in the valleys. These tussocks form a microtopography or a river valley. Currently, the most commonly used technology to register the terrain topography is an Airborne Laser Scanning (ALS), but in the case of the tussocks and the dense vegetation it generates high errors on elevation in the areas of the sedges (Carex appropinquata). This study concerns the Upper Biebrza Valley which is located in the northeastern Poland. For purpose of our work we used Terrestrial Laser Scanner (TLS) technology to determine microtopography of selected fields. Before measurements, the green part of the sedge was cut in selected measurements fields. It make possible to register only tussocks shape. Next, step was collection of the airborne ALS data of the valley with density of 8 points/sq m. The experimental field was divided on two sub-fields: one was cut and scanned using TLS before ALS collection, while the second after. Data collected as ALS and the TLS were then compared. The accuracy of the ALS data depends on the land cover of an area, while TLS accuracy is around 2 millimeters (when georeferenced it depends on the accuracy of reference points - in our case it was made using GPS RTK which gave us accuracy of few centimeters). The analysis shown that differences between ALS measurements and TLS on leaf free area is on average of 5 centimeters, while on areas which were not mowed it grows up to 0,5 m. Thanks to this studies we were able to determine water storage possibilities of valley while considering the tussocks shape.

A Novel Animal Model for Investigating the Neural Basis of Focal Dystonia

DTIC Science & Technology

2016-09-01

basal ganglia as the predisposing condition and dry eye as an environmental trigger. Based on experiments during the 1st year of the grant, our...experiments and preliminary recordings from the superior colliculus. 15. SUBJECT TERMS Dystonia, benign essential blepharospasm, dry eye , motor...that hypersynchronized, 7 Hz neuronal oscilla‐ tions of the basal ganglia created the predisposing condition and that  eye  irritation from  dry   eye  was

[Neurogenic oropharyngeal dysphagia is a frequent condition in patients admitted to the ICU].

PubMed

Pedersen, Anette Barbre; Kjærsgaard, Annette; Larsen, Jens Kjærgaard Rolighed; Nielsen, Lars Hedemann

2015-03-02

Neurogenic oropharyngeal dysphagia (NOD) is a frequent condition in neurological patients admitted to the ICU, particularly in patients with brainstem lesions. The CNS damage itself can predispose to dysphagia, but also the treatment and preventive measures may predispose to and exacerbate the condition. Frequent pneumonia in a neurological patient is a warning signal that should cause screening for dysphagia. Complications are serious and can be fatal. Neurological patients should be examined for NOD before decannulation. Treatment is difficult, so prevention and multidisciplinary neurological rehabilitation is important.

Neotectonic implications by geophysical surveys of topographic features identified by Airborne Laser Scanning in the Neusiedlersee/Ferto area (Austria/Hungary)

NASA Astrophysics Data System (ADS)

Timár, G.; Székely, B.; Zámolyi, A.; Houseman, G.; Stuart, G.; Grasemann, B.; Dombrádi, E.; Galsa, A.; Spahic, D.; Draganits, E.

2009-04-01

The area around the Lake Neudsiedlersee (Lake Fertő in Hungarian) was analysed to understand its neotectonic activity and gather possible explanations of the features of the topography and microtopography. The area consists of two, considerably different parts in terms of topography and geomorphology. The western and north-western shores of the lake are connected to the Leitha Mts., a low ridge (its relative height is about 300 meters) that connects the Alpine orogen in the SW with the Carpathians to NE bounded by active strike-slip faulting. In this part of the area, several outcrops were investigated, of which the one at St. Margarethen was systematically measured by multielectric sounding and GPR, and an other one at St. Georgen, north of Eisenstadt, was used for auxiliary data gathering. The eastern and southern shores, belonging to the Pannonian Basin, are mostly flatlands, parts of the Little Hungarian Plain with extremely low relief and no real natural drainage. The small variations of the surface altitude (less than ten meters), referred to as microtopography here, are due to elongated ridges and extremely shallow perennial or temporal playa lakes. In order to understand better the subsurface structure, a multimethod approach has been applied. Geophysical survey methods (vertical electric sounding, land seismics, gravity measurements) were carried out to describe the layer structure of this area, especially a zone, north of Illmitz, connected to interesting elements of microtopography. The identification of microtopographic features were carried out using high resolution digital elevation datasets, derived from Aerial Laser Scannings (ALS). Seismic measurements were carried out also in the lake itself to understand the structural geological settings of the lake bottom to the depth of ca. 50 meters. All of these measurements were made in the framework of a common student fieldwork of the Eötvös University, the University of Leeds and the University of Vienna. Fault lines that can be interpreted active in neotectonic point of view were found below the lake by water seismic. These faults displaced young sediments as well. Similar patterns were found at the outcrop of St. Margarethen near to the western shore of the lake and were followed underground by the geophysics. However, in the eastern shore the geophysics showed no sign of active tectonics in the upper fifty meters of the sediment. Changes in physical characteristics (resistivity, wave propagation velocity) were mapped in 3D and were connected to the ALS microtopographic features. The material of the small elevated zones occurred to be gravel and coarse sand and the basement of this layer was a low-resistivity clay. Previously these structures were interpreted as large-scale deformations bands; this solution is still feasible in the light of the results. A further possible interpretation of this structure is that the topographic undulations are connected to the former alluvial fan of the Paleo-Danube River, sedimented from north. ELTE-Leeds-UniWien Workgroup team: M. Al-Dakheel, H. Al-Nasser, M. Al-Shaks, M. Bolton, D. Cornwall, A. Deák, S. Devlin, M. Diel, Á. Domján, P. Dövényi, J. Elgenes, U. Exner, N. Foks, Z. Hámori, M. Hashim, F. Horváth, L. Jackson, T. Katona, K. Kelevitz, A. Kelly, E. Király, M. Kóbor, G. Kocsis, A. Kovács, G. Kovács, I. Kudó, P. Lőrinczy, E. Marinov, J. Mound, L. Pál, D. Palotás, T. Roome, Zs. Sári, G. Surányi, É. Szántó, V. Szabó, G. Taller, A. Weedon, V. Werovszky

Absence of the predisposing factors and signs and symptoms usually associated with overreaching and overtraining in physical fitness centers.

PubMed

Ackel-D'Elia, Carolina; Vancini, Rodrigo Luiz; Castelo, Adauto; Nouailhetas, Viviane Louise Andrée; Silva, Antonio Carlos da

2010-01-01

The aim of this study was to evaluate the occurrence of the well-known predisposing factors and signs and symptoms usually associated with either overreaching or overtraining syndrome in physical fitness centers in São Paulo City, Brazil. A questionnaire consisting of 13 question groups pertaining to either predisposing factors (1-7) or signs and symptoms (8-13) was given to 413 subjects. The general training schedule of the volunteers was characterized by workout sessions of 2.18 ± 0.04 h for a total of 11.0 ± 0.3 h/week for 33 ± 2 months independent of the type of exercise performed (walking, running, spinning, bodybuilding and stretching). A mean score was calculated ranging from 1 (completely absent) to 5 (severe) for each question group. A low occurrence was considered to be a question group score lower than 4, which was observed in all 13 question groups. The psychological evaluation by POMS Mood State Questionnaire indicated a normal non-inverted iceberg. The hematological parameters, creatine kinase activity, cortisol, total testosterone and free testosterone concentrations were within the normal ranges for the majority of the volunteers selected for this analysis (n = 60). According to the questionnaire score analysis, no predisposing factors or signs and symptoms usually associated with either overreaching or overtraining were detected among the members of physical fitness centers in São Paulo City, Brazil. This observation was corroborated by the absence of any significant hematological or stress hormone level alterations in blood analyses of the majority of the selected volunteers (n = 60).

Malnutrition at Age 3 Years and Externalizing Behavior Problems at Ages 8, 11, and 17 Years

PubMed Central

Liu, Jianghong; Raine, Adrian; Venables, Peter H.; Mednick, Sarnoff A.

2006-01-01

Objective Poor nutrition is thought to predispose to externalizing behavior problems, but to date there appear to have been no prospective longitudinal studies testing this hypothesis. This study assessed whether 1) poor nutrition at age 3 years predisposes to antisocial behavior at ages 8, 11, and 17 years, 2) such relationships are independent of psychosocial adversity, and 3) IQ mediates the relationship between nutrition and externalizing behavior problems. Method The participants were drawn from a birth cohort (N=1,795) in whom signs of malnutrition were assessed at age 3 years, cognitive measures were assessed at ages 3 and 11 years, and antisocial, aggressive, and hyperactive behavior was assessed at ages 8, 11, and 17 years. Results In relation to comparison subjects (N=1,206), the children with malnutrition signs at age 3 years (N=353) were more aggressive or hyperactive at age 8 years, had more externalizing problems at age 11, and had greater conduct disorder and excessive motor activity at age 17. The results were independent of psychosocial adversity and were not moderated by gender. There was a dose-response relationship between degree of malnutrition and degree of externalizing behavior at ages 8 and 17. Low IQ mediated the link between malnutrition and externalizing behavior at ages 8 and 11. Conclusions These results indicate that malnutrition predisposes to neurocognitive deficits, which in turn predispose to persistent externalizing behavior problems throughout childhood and adolescence. The findings suggest that reducing early malnutrition may help reduce later antisocial and aggressive behavior. PMID:15514400

Cardiovascular Disease Risk Varies by Birth Month in Canines.

PubMed

Boland, Mary Regina; Kraus, Marc S; Dziuk, Eddie; Gelzer, Anna R

2018-05-17

The canine heart is a robust physiological model for the human heart. Recently, birth month associations have been reported and replicated in humans using clinical health records. While animals respond readily to their environment in the wild, a systematic investigation of birth season dependencies among pets and specifically canines remains lacking. We obtained data from the Orthopedic Foundation of Animals on 129,778 canines representing 253 distinct breeds. Among canines that were not predisposed to cardiovascular disease, a clear birth season relationship is observed with peak risk occurring in June-August. Our findings indicate that acquired cardiovascular disease among canines, especially those that are not predisposed to cardiovascular disease, appears birth season dependent. The relative risk of cardiovascular disease for canines not predisposed to cardiovascular disease was as high as 1.47 among July pups. The overall adjusted odds ratio, when mixed breeds were excluded, for the birth season effect was 1.02 (95% CI: 1.002, 1.047, p = 0.032) after adjusting for breed and genetic cardiovascular predisposition effects. Studying birth season effects in model organisms can help to elucidate potential mechanisms behind the reported associations.

Diagnosis and medical treatment of otitis externa in the dog and cat.

PubMed

Jacobson, L S

2002-12-01

Otitis externa is no longer viewed as an isolated disease of the ear canal, but is a syndrome that is often a reflection of underlying dermatological disease. Causes are classified as predisposing (increase the risk of otitis); primary (directly induce otitis), secondary (contribute to otitis only in an abnormal ear or in conjunction with predisposing factors) and perpetuating (result from inflammation and pathology in ear, prevent resolution of otitis). Common primary causes include foreign bodies, hypersensitivity (particularly atopy and food allergy), keratinisation disorders (most commonly primary idiopathic seborrhoea and hypothyroidism) and earmites, particularly in cats. A systematic diagnostic procedure is required to identify causes and contributing factors. This should include history, clinical examination, otoscopy and cytology in all cases and culture and sensitivity as well as otitis media assessment and biopsy in severe and recurrent cases. Ancillary tests may be required depending on the underlying cause. Treatment consists of identifying and addressing predisposing and primary factors; cleaning the ear canal; topical therapy; systemic therapy where necessary; client education; follow-up; and preventive and maintenance therapy as required.

Association of poor childhood fear conditioning and adult crime.

PubMed

Gao, Yu; Raine, Adrian; Venables, Peter H; Dawson, Michael E; Mednick, Sarnoff A

2010-01-01

Amygdala dysfunction is theorized to give rise to poor fear conditioning, which in turn predisposes to crime, but it is not known whether poor conditioning precedes criminal offending. This study prospectively assessed whether poor fear conditioning early in life predisposes to adult crime in a large cohort. Electrodermal fear conditioning was assessed in a cohort of 1,795 children at age 3, and registration for criminal offending was ascertained at age 23. In a case-control design, 137 cohort members with a criminal record were matched on gender, ethnicity, and social adversity with 274 noncriminal comparison members. Statistical analyses compared childhood fear conditioning for the two groups. Criminal offenders showed significantly reduced electrodermal fear conditioning at age 3 compared to matched comparison subjects. Poor fear conditioning at age 3 predisposes to crime at age 23. Poor fear conditioning early in life implicates amygdala and ventral prefrontal cortex dysfunction and a lack of fear of socializing punishments in children who grow up to become criminals. These findings are consistent with a neurodevelopmental contribution to crime causation.

Assessing factors that may predispose Minnesota farms to wolf predation on cattle

USGS Publications Warehouse

Mech, L.D.; Harper, E.K.; Meier, T.J.; Paul, W.J.

2000-01-01

Wolf (Canis lupus) depredations on livestock cause considerable conflict and expense in Minnesota. Furthermore, claims are made that such depredations are fostered by the type of animal husbandry practiced. Thus, we tried to detect factors that might predispose farms in Minnesota to wolf depredations. We compared results of interviews with 41 cattle farmers experiencing chronic cattle losses to wolves (chronic farms) with results from 41 nearby matched farms with no wolf losses to determine farm characteristics or husbandry practices that differed and that therefore might have affected wolf depredations. We also used a Geographic Information System (GIS) to detect any habitat differences between the 2 types of farms. We found no differences between chronic and matched farms in the 11 farm characteristics and management practices that we surveyed, except that farms with chronic losses were larger, had more cattle, and had herds farther from human dwellings. Habitat types were the same around farms with and without losses. The role of proper carcass disposal as a possible factor predisposing farms to wolf depredations remains unclear

Expediting support for the pregnant mothers to obtain antenatal care at public health facilities in rural areas of Balochistan province, Pakistan.

PubMed

Ghaffar, Abdul; Pongpanich, Sathirakorn; Ghaffar, Najma; Chapman, Robert Sedgwick; Mureed, Sheh

2015-01-01

To identify, and compare relative importance of, factors associated with antenatal care (ANC) utilization in rural Balochistan, toward framing a policy to increase such utilization. This cross sectional study was conducted among 513 pregnant women in Jhal Magsi District, Balochistan, in 2011. A standardized interviewer-administered questionnaire was used. Predisposing, enabling, and reinforcing factors were evaluated with generalized linear models (Poisson distribution and log link). Prevalence of any ANC was only 14.4%. Predisposing, enabling, and reinforcing factors were all important determinants of ANC utilization. Reinforcing factors were clearly most important, husband's support for ANC was more important than support from other community members. Among predisposing factors, higher income, education, occupation, and better knowledge regarding benefits of ANC were positively and statistically significantly associated with ANC However increased number of children showed negative association. Complications free pregnancy showed positive significant association with ANC at public health facility among enabling factors. It is very important to increase antenatal care utilization in the study area and similar areas. Policy to achieve this should focus on enhancing support from the husband.

Community-acquired adult Escherichia coli meningitis leading to diagnosis of unrecognized retropharyngeal abscess and cervical spondylodiscitis: a case report.

PubMed

Kohlmann, Rebekka; Nefedev, Andrey; Kaase, Martin; Gatermann, Sören G

2015-12-12

Escherichia coli is a rare cause of community-acquired meningitis in adults unless predisposing factors are present (e.g., previous penetrating cranio-cerebral injury or neurosurgery, immunosuppression, chronic alcoholism, history of cancer, diabetes mellitus, advanced age). We describe the case of a 53-year-old woman, resident in Germany, suffering from community-acquired bacterial meningitis caused by CTX-M-9 type extended spectrum β-lactamase producing Escherichia coli. Because typical predisposing factors were not apparent, pathogen identification resulted in expanded diagnostics to exclude a distant or contiguous primary focus. By magnetic resonance tomography, a previously unrecognized large retropharyngeal abscess with cervical spondylodiscitis was detected. In retrospect, the patient had complained about neck pain for a few weeks prior to meningitis onset, but the symptoms were interpreted as being related to a herniated disk. Meningitis and osteomyelitis resolved completely under surgical treatment and meropenem therapy. In case of adult Escherichia coli meningitis, underlying diseases should always be carefully excluded, especially if predisposing factors are not apparent.

Broadening the spectrum of SMARCB1-associated malignant tumors: a case of uterine leiomyosarcoma in a patient with schwannomatosis.

PubMed

Paganini, Irene; Sestini, Roberta; Cacciatore, Matilde; Capone, Gabriele L; Candita, Luisa; Paolello, Concetta; Sbaraglia, Marta; Dei Tos, Angelo P; Rossi, Sabrina; Papi, Laura

2015-08-01

Schwannomatosis is a tumor predisposition syndrome characterized by development of multiple intracranial, spinal, and peripheral schwannomas. Constitutional alterations in either SMARCB1 or LZTR1 on 22q are responsible of the phenotype. We describe a 34-year-old woman who developed multiple benign peripheral sheath tumors and a uterine leiomyosarcoma. The patient carried a de novo constitutional alteration in exon 8 of SMARCB1, c.1118G > A, which destroyed the splice donor site of intron 8. Two schwannomas and the leiomyosarcoma of the patient retained the SMARCB1 mutation; in addition, the tumors showed loss of the normal chromosome 22. In conclusion, our findings enlarged the spectrum of SMARCB1-predisposing tumors and demonstrated, for the first time, the association of a malignant smooth muscle tumor to schwannomatosis. Therefore, clinicians should definitely be aware that a constitutional SMARCB1 mutation, which mainly predisposes to benign nerve sheath tumors, may also predispose to aggressive neoplasms throughout life, within an unexpected spectrum. Copyright © 2015 Elsevier Inc. All rights reserved.

Nested Inversion Polymorphisms Predispose Chromosome 22q11.2 to Meiotic Rearrangements.

PubMed

Demaerel, Wolfram; Hestand, Matthew S; Vergaelen, Elfi; Swillen, Ann; López-Sánchez, Marcos; Pérez-Jurado, Luis A; McDonald-McGinn, Donna M; Zackai, Elaine; Emanuel, Beverly S; Morrow, Bernice E; Breckpot, Jeroen; Devriendt, Koenraad; Vermeesch, Joris R

2017-10-05

Inversion polymorphisms between low-copy repeats (LCRs) might predispose chromosomes to meiotic non-allelic homologous recombination (NAHR) events and thus lead to genomic disorders. However, for the 22q11.2 deletion syndrome (22q11.2DS), the most common genomic disorder, no such inversions have been uncovered as of yet. Using fiber-FISH, we demonstrate that parents transmitting the de novo 3 Mb LCR22A-D 22q11.2 deletion, the reciprocal duplication, and the smaller 1.5 Mb LCR22A-B 22q11.2 deletion carry inversions of LCR22B-D or LCR22C-D. Hence, the inversions predispose chromosome 22q11.2 to meiotic rearrangements and increase the individual risk for transmitting rearrangements. Interestingly, the inversions are nested or flanking rather than coinciding with the deletion or duplication sizes. This finding raises the possibility that inversions are a prerequisite not only for 22q11.2 rearrangements but also for all NAHR-mediated genomic disorders. Copyright © 2017. Published by Elsevier Inc.

A magnetic resonance imaging study of abnormalities of the patella and patellar tendon that predispose children to acute patellofemoral dislocation.

PubMed

Yılmaz, Barış; Çiçek, Esin Derin; Şirin, Evrim; Özdemir, Güzelali; Karakuş, Özgün; Muratlı, Hasan Hilmi

This study compared 20 children hospitalised with acute patellofemoral dislocation with an age-matched healthy control group with no history of knee problems or patellar dislocation. The following morphological parameters were significantly different between the groups: the mean patellar width and length, mean sulcus depth, mean patellar tendon width and total patellar volume. The magnetic resonance imaging findings of this study suggested that structurally smaller than normal patella and patellar tendon volumes are predisposing factors for acute patellofemoral dislocation. Copyright © 2016 Elsevier Inc. All rights reserved.

Cleared for the visual approach: Human factor problems in air carrier operations

NASA Technical Reports Server (NTRS)

Monan, W. P.

1983-01-01

The study described herein, a set of 353 ASRS reports of unique aviation occurrences significantly involving visual approaches was examined to identify hazards and pitfalls embedded in the visual approach procedure and to consider operational practices that might help avoid future mishaps. Analysis of the report set identified nine aspects of the visual approach procedure that appeared to be predisposing conditions for inducing or exacerbating the effects of operational errors by flight crew members or controllers. Predisposing conditions, errors, and operational consequences of the errors are discussed. In a summary, operational policies that might mitigate the problems are examined.

Acute Intraoperative Pulmonary Aspiration

PubMed Central

Nason, Katie S.

2015-01-01

Synopsis Acute intraoperative aspiration is a potentially fatal complication with significant associated morbidity. Patients undergoing thoracic surgery are at increased risk for anesthesia-related aspiration, largely due to the predisposing conditions associated with this complication. Awareness of the risk factors, predisposing conditions, maneuvers to decrease risk and immediate management options by both the thoracic surgeon and the anesthesia team is imperative to reducing risk and optimizing patient outcomes associated with acute intraoperative pulmonary aspiration. Based on the root-cause analyses that many of the aspiration events can be traced back to provider factors, having an experienced anesthesiologist present for high-risk cases is also critical. PMID:26210926

Booker T. Washington and the Secret of Hypertension in African Americans.

PubMed

Mackowiak, Philip A

2016-10-01

Booker T. Washington rose from slavery to become one of the most admired Americans of his time. He died of long-standing malignant hypertension on November 14, 1915. At that time the medical profession was just beginning to recognize the importance of hypertension as a risk factor for cardiovascular disease. In spite of intensive research fueled by ongoing speculation, why Washington might have been predisposed to the ravages of hypertension, and African Americans continue to be so predisposed, is a secret yet to be told. Copyright © 2016 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

[Alexithymia--definition, causes and participation in the etiology of diseases].

PubMed

Orzechowska, Agata; Denys, Katarzyna; Gałecki, Piotr

2014-08-01

Alexithymia leads to an inability to recognize and identity feelings, use of language to describe the feelings and the inability to distinguish between emotions and bodily symptoms. Is treated as a stable personality trait, which along with other personality factors predispose to presence a variety of mental and physical diseases. Alexithymia is considered to be a personality trait which together with other environmental factors predispose to worsening of somatic diseases and may contribute to the emergence of mental disorders. The direction of this dependence is not exactly known for heterogeneity alexythymia etiology, and therefore requires further studies.

Mesenchymal stromal cells of osteosarcoma patients do not show evidence of neoplastic changes during long-term culture.

PubMed

Buddingh, Emilie P; Ruslan, S Eriaty N; Reijnders, Christianne M A; Szuhai, Karoly; Kuijjer, Marieke L; Roelofs, Helene; Hogendoorn, Pancras C W; Maarten Egeler, R; Cleton-Jansen, Anne-Marie; Lankester, Arjan C

2015-01-01

In vitro expanded mesenchymal stromal cells (MSCs) are increasingly used as experimental cellular therapy. However, there have been concerns regarding the safety of their use, particularly with regard to possible oncogenic transformation. MSCs are the hypothesized precursor cells of high-grade osteosarcoma, a tumor with often complex karyotypes occurring mainly in adolescents and young adults. To determine if MSCs from osteosarcoma patients could be predisposed to malignant transformation we cultured MSCs of nine osteosarcoma patients and five healthy donors for an average of 649 days (range 601-679 days). Also, we compared MSCs derived from osteosarcoma patients at diagnosis and from healthy donors using genome wide gene expression profiling. Upon increasing passage, increasing frequencies of binucleate cells were detected, but no increase in proliferation suggestive of malignant transformation occurred in MSCs from either patients or donors. Hematopoietic cell specific Lyn substrate 1 (HLCS1) was differentially expressed (fold change 0.25, P value 0.0005) between MSCs of osteosarcoma patients (n = 14) and healthy donors (n = 9). This study shows that although HCLS1 expression was downregulated in MSCs of osteosarcoma patients and binucleate cells were present in both patient and donor derived MSCs, there was no evidence of neoplastic changes to occur during long-term culture.

The Potential Cardiotoxic Effects of Exercise.

PubMed

La Gerche, André

2016-04-01

The emerging controversy related to the potential cardiotoxic effects of high doses of intense exercise need to be considered among the much stronger evidence that supports the pleomorphic benefits of exercise as a whole. However, there is fairly compelling evidence to support the association between long-term sport practice and an increased prevalence of atrial fibrillation and the fact that this relates to a chronic altered atrial substrate. This article was designed to challenge the reader with speculative science that suggests that exercise might promote permanent structural changes in the myocardium which can, in some individuals, predispose to arrhythmias. In terms of long-term health outcomes, it would seem that these small risks are outweighed by the many other benefits of exercise, including a likely decrease in atherosclerotic vascular events, although some recent results have brought into question whether the protective benefits of exercise on vascular events also extends to high-intensity exercise training. Above all else, in this article we sought to highlight current controversies to stimulate research on the many unanswered questions. In particular, there is a lack of adequately powered prospective studies from which we can measure health outcomes and their relationship to exercise-induced cardiac remodelling. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Ventral dermatitis in rowi (Apteryx rowi) due to cutaneous larval migrans.

PubMed

Gartrell, B D; Argilla, L; Finlayson, S; Gedye, K; Gonzalez Argandona, A K; Graham, I; Howe, L; Hunter, S; Lenting, B; Makan, T; McInnes, K; Michael, S; Morgan, K J; Scott, I; Sijbranda, D; van Zyl, N; Ward, J M

2015-04-01

The rowi is a critically endangered species of kiwi. Young birds on a crèche island showed loss of feathers from the ventral abdomen and a scurfy dermatitis of the abdominal skin and vent margin. Histology of skin biopsies identified cutaneous larval migrans, which was shown by molecular sequencing to be possibly from a species of Trichostrongylus as a cause of ventral dermatitis and occasional ulcerative vent dermatitis. The predisposing factors that led to this disease are suspected to be the novel exposure of the rowi to parasites from seabirds or marine mammals due to the island crèche and the limited management of roost boxes. This is the first instance of cutaneous larval migrans to be recorded in birds. Severe and fatal complications of the investigation resulted in the death of eight birds of aspergillosis and pulmonary complications associated with the use of bark as a substrate in hospital. Another bird died of renal failure during the period of hospitalisation despite oral and intravenous fluid therapy. The initiating cause of the renal failure was not determined. These complications have the potential to undermine the working relationship between wildlife veterinarians and conservation managers. This case highlights that intensive conservation management can result in increased opportunities for novel routes of cross-species pathogen transmission.

Transgenerational epigenetic effects on animal behaviour.

PubMed

Jensen, Per

2013-12-01

Over the last decade a shift in paradigm has occurred with respect to the interaction between environment and genes. It is now clear that animal genomes are regulated to a large extent as a result of input from environmental events and experiences, which cause short- and long-term modifications in epigenetic markings of DNA and histones. In this review, the evidence that such epigenetic modifications can affect the behaviour of animals is explored, and whether such acquired behaviour alterations can transfer across generation borders. First, the mechanisms by which experiences cause epigenetic modifications are examined. This includes, for example, methylation of cytosine in CpG positions and acetylation of histones, and studies showing that this can be modified by early experiences. Secondly, the evidence that specific modifications in the epigenome can be the cause of behaviour variation is reviewed. Thirdly, the extent to which this phenotypically active epigenetic variants can be inherited either through the germline or through reoccurring environmental conditions is examined. A particularly interesting observation is that epigenetic modifications are often linked to stress, and may possibly be mediated by steroid effects. Finally, the idea that transgenerationally stable epigenetic variants may serve as substrates for natural selection is explored, and it is speculated that they may even predispose for directed, non-random mutations. Copyright © 2013 Elsevier Ltd. All rights reserved.

Motivational Processes Underlying Substance Abuse Disorder.

PubMed

Meyer, Paul J; King, Christopher P; Ferrario, Carrie R

2016-01-01

Drug addiction is a syndrome of dysregulated motivation, evidenced by intense drug craving and compulsive drug-seeking behavior. In the search for 'common neurobiological substrates of addiction to different classes of drugs, behavioral neuroscientists have attempted to determine the neural basis for a number of motivational concepts and describe how they are changed by repeated drug use. Here, we describe these concepts and summarize previous work describing three major neural systems that play distinct roles in different conceptual aspects of motivation: (1) a nigrostriatal system that is involved in two forms of instrumental learning, (2) a ventral striatal system that is involved in Pavlovian incentive motivation and negative reinforcement, and (3) frontal cortical areas that regulate decision making and motivational processes. Within striatal systems, drug addiction can involve a transition from goal-oriented, incentive processes to automatic, habit-based responding. In the cortex, weak inhibitory control is a predisposing factor to, as well as a consequence of, repeated drug intake. However, these transitions are not absolute, and addiction can occur without a transition to habit-based responding, occurring as a result of the overvaluation of drug outcomes and hypersensitivity to incentive properties of drug-associated cues. Finally, we point out that addiction is not monolithic and can depend not only on individual differences between addicts, but also on the neurochernical action of specific drug classes.

The fate of (13)C-labelled and non-labelled inulin predisposed to large bowel fermentation in rats.

PubMed

Butts, Christine A; Paturi, Gunaranjan; Tavendale, Michael H; Hedderley, Duncan; Stoklosinski, Halina M; Herath, Thanuja D; Rosendale, Douglas; Roy, Nicole C; Monro, John A; Ansell, Juliet

2016-04-01

The fate of stable-isotope (13)C labelled and non-labelled inulin catabolism by the gut microbiota was assessed in a healthy rat model. Sprague-Dawley male rats were randomly assigned to diets containing either cellulose or inulin, and were fed these diets for 3 days. On day (d) 4, rats allocated to the inulin diet received (13)C-labelled inulin. The rats were then fed the respective non-labelled diets (cellulose or inulin) until sampling (d4, d5, d6, d7, d10 and d11). Post feeding of (13)C-labelled substrate, breath analysis showed that (13)C-inulin cleared from the host within a period of 36 hours. Faecal (13)C demonstrated the clearance of inulin from gut with a (13)C excess reaching maximum at 24 hours (d5) and then declining gradually. There were greater variations in caecal organic acid concentrations from d4 to d6, with higher concentrations of acetic, butyric and propionic acids observed in the rats fed inulin compared to those fed cellulose. Inulin influenced caecal microbial glycosidase activity, increased colon crypt depth, and decreased the faecal output and polysaccharide content compared to the cellulose diet. In summary, the presence of inulin in the diet positively influenced large bowel microbial fermentation.

Ventral dermatitis in rowi (Apteryx rowi) due to cutaneous larval migrans

PubMed Central

Gartrell, B.D.; Argilla, L.; Finlayson, S.; Gedye, K.; Gonzalez Argandona, A.K.; Graham, I.; Howe, L.; Hunter, S.; Lenting, B.; Makan, T.; McInnes, K.; Michael, S.; Morgan, K.J.; Scott, I.; Sijbranda, D.; van Zyl, N.; Ward, J.M.

2014-01-01

The rowi is a critically endangered species of kiwi. Young birds on a crèche island showed loss of feathers from the ventral abdomen and a scurfy dermatitis of the abdominal skin and vent margin. Histology of skin biopsies identified cutaneous larval migrans, which was shown by molecular sequencing to be possibly from a species of Trichostrongylus as a cause of ventral dermatitis and occasional ulcerative vent dermatitis. The predisposing factors that led to this disease are suspected to be the novel exposure of the rowi to parasites from seabirds or marine mammals due to the island crèche and the limited management of roost boxes. This is the first instance of cutaneous larval migrans to be recorded in birds. Severe and fatal complications of the investigation resulted in the death of eight birds of aspergillosis and pulmonary complications associated with the use of bark as a substrate in hospital. Another bird died of renal failure during the period of hospitalisation despite oral and intravenous fluid therapy. The initiating cause of the renal failure was not determined. These complications have the potential to undermine the working relationship between wildlife veterinarians and conservation managers. This case highlights that intensive conservation management can result in increased opportunities for novel routes of cross-species pathogen transmission. PMID:25830099

Absence of the predisposing factors and signs and symptoms usually associated with overreaching and overtraining in physical fitness centers

PubMed Central

Ackel‐D'Elia, Carolina; Vancini, Rodrigo Luiz; Castelo, Adauto; Nouailhetas, Viviane Louise Andrée; da Silva, Antonio Carlos

2010-01-01

OBJECTIVE: The aim of this study was to evaluate the occurrence of the well‐known predisposing factors and signs and symptoms usually associated with either overreaching or overtraining syndrome in physical fitness centers in São Paulo City, Brazil. METHOD: A questionnaire consisting of 13 question groups pertaining to either predisposing factors (1‐7) or signs and symptoms (8‐13) was given to 413 subjects. The general training schedule of the volunteers was characterized by workout sessions of 2.18 ± 0.04 h for a total of 11.0 ± 0.3 h/week for 33 ± 2 months independent of the type of exercise performed (walking, running, spinning, bodybuilding and stretching). A mean score was calculated ranging from 1 (completely absent) to 5 (severe) for each question group. A low occurrence was considered to be a question group score lower than 4, which was observed in all 13 question groups. RESULTS: The psychological evaluation by POMS Mood State Questionnaire indicated a normal non‐inverted iceberg. The hematological parameters, creatine kinase activity, cortisol, total testosterone and free testosterone concentrations were within the normal ranges for the majority of the volunteers selected for this analysis (n  =  60). CONCLUSION: According to the questionnaire score analysis, no predisposing factors or signs and symptoms usually associated with either overreaching or overtraining were detected among the members of physical fitness centers in São Paulo City, Brazil. This observation was corroborated by the absence of any significant hematological or stress hormone level alterations in blood analyses of the majority of the selected volunteers (n  =  60). PMID:21243291

Health care costs in the elderly in Germany: an analysis applying Andersen’s behavioral model of health care utilization

PubMed Central

2014-01-01

Background To analyze the association of health care costs with predisposing, enabling, and need factors, as defined by Andersen’s behavioral model of health care utilization, in the German elderly population. Methods Using a cross-sectional design, cost data of 3,124 participants aged 57–84 years in the 8-year-follow-up of the ESTHER cohort study were analyzed. Health care utilization in a 3-month period was assessed retrospectively through an interview conducted by trained study physicians at respondents’ homes. Unit costs were applied to calculate health care costs from the societal perspective. Socio-demographic and health-related variables were categorized as predisposing, enabling, or need factors as defined by the Andersen model. Multimorbidity was measured by the Cumulative Illness Rating Scale for Geriatrics (CIRS-G). Mental health status was measured by the SF-12 mental component summary (MCS) score. Sector-specific costs were analyzed by means of multiple Tobit regression models. Results Mean total costs per respondent were 889 € for the 3-month period. The CIRS-G score and the SF-12 MCS score representing the need factor in the Andersen model were consistently associated with total, inpatient, outpatient and nursing costs. Among the predisposing factors, age was positively associated with outpatient costs, nursing costs, and total costs, and the BMI was associated with outpatient costs. Conclusions Multimorbidity and mental health status, both reflecting the need factor in the Andersen model, were the dominant predictors of health care costs. Predisposing and enabling factors had comparatively little impact on health care costs, possibly due to the characteristics of the German social health insurance system. Overall, the variables used in the Andersen model explained only little of the total variance in health care costs. PMID:24524754

Stress-related sleep vulnerability and maladaptive sleep beliefs predict insomnia at long-term follow-up.

PubMed

Yang, Chien-Ming; Hung, Chih-Ying; Lee, Hsin-Chien

2014-09-15

Vulnerability to stress-related sleep disturbances and maladaptive sleep beliefs has been proposed to be predisposing factors for insomnia. Yet previous studies addressing these factors have been cross-sectional in nature and could not be used to infer the time sequences of the association. The current study used a six-year follow-up to examine the predisposing roles of these two factors and their interactions with major life stressors in the development of insomnia. One hundred seventeen college students recruited for a survey in 2006 participated in this follow-up survey in 2012. In 2006, they completed a packet of questionnaires including the Dysfunctional Beliefs and Attitudes about Sleep Questionnaire, 10-item version (DBAS-10), the Ford Insomnia Response to Stress Test (FIRST), and the Pittsburgh Sleep Quality Index (PSQI); in 2012 they completed the Insomnia Severity Index (ISI) and the modified Life Experiences Survey (LES). Fourteen of the participants were found to suffer from insomnia as measured by the ISI. Logistic regression showed that scores on both DBAS-10 and FIRST could predict insomnia at follow-up. When the interaction of DBAS-10 and LES and that of FIRST and LES were added, both DBAS-10 and FIRST remained significant predictors, while the interaction of FIRST and LES showed a near-significant trend in predicting insomnia. The results showed that both vulnerability to stress-related sleep disturbances and maladaptive sleep beliefs are predisposing factors for insomnia. The hypothesized interaction effect between sleep vulnerability and major life stressors was found to be marginal. The maladaptive sleep beliefs, on the other hand, showed a predisposing effect independent from the influences of negative life events. © 2014 American Academy of Sleep Medicine.

Arterial elastic fiber structure. Function and potential roles in acute aortic dissection.

PubMed

Pratt, B; Curci, J

2010-10-01

The lethality of acute aortic dissection is well recognized. Successful treatment and prevention of aortic dissection is going to be dependent upon an improved understanding of the molecular and physiologic events which predispose to dissection development and propagation. In this review, we will focus on the elastic fiber, one of the critical elements of the aortic wall matrix. Mechanical or functional failure of the elastin in the wall of the aorta likely predisposes to dissection as well as the post-dissection aortic degeneration with aneurysm formation. Insight into the role of the elastin and the elastic fiber in aortic dissection has recently been accelerated by research into the molecular mechanisms associated with hereditary propensity for aortic dissection, such as Marfan syndrome. These studies have implicated both structural and metabolic contributions of alterations in the scaffolding proteins in matrix elastic fibers. In particular, increased transforming growth factor-β (TGF-β) activity may play a prominent role in predisposing the aortic wall to dissection. The events which predispose to post-dissection aortic degeneration are somewhat less well defined. However, the loss of the structural integrity of the remaining elastic fibers leaves the wall weaker and prone to dilatation and rupture. It appears likely that the upregulation of several potent proteases, particularly those of the matrix metalloproteinase (MMP) family such as MMP-9, are participating in the subsequent matrix damage. Novel medical treatments based on this pathologic data have been proposed and in some cases have made it to clinical trials. The ongoing study evaluating whether therapeutic inhibition of TGF-β may be useful in reducing the risk of aortic dissection in patients at high risk represents one promising new strategy in the treatment of this deadly disease.

Predisposing cardiac conditions, interventional procedures, and antibiotic prophylaxis among patients with infective endocarditis.

PubMed

Chirillo, Fabio; Faggiano, Pompilio; Cecconi, Moreno; Moreo, Antonella; Squeri, Angelo; Gaddi, Oscar; Cecchi, Enrico

2016-09-01

Efficacy and safety of antibiotic prophylaxis (AP) for prevention of infective endocarditis (IE) in patients with predisposing cardiac condition (PCC) undergoing invasive procedures is still debated. We sought to assess the prevalence of PCC, the type of interventional procedures preceding the onset of symptoms, and the usefulness of AP in a large cohort of consecutive patients with definite IE. We examined 677 (median age 65.34 years; male 492 [73%]) consecutive patients with IE enrolled from July 2007 through 2010 into the Italian Registry of Infective Endocarditis. Predisposing cardiac condition was present in 341 patients (50%).Thirty-two patients (4.7%) underwent dental procedures. Of 20 patients with PCC undergoing dental procedure, 13 had assumed AP. Viridans group streptococci were isolated from blood cultures in 8 of 20 patients with PCC and prior dental procedure. Nondental procedures preceded IE in 139 patients (21%). They were significantly older and had more comordibities compared with patients undergoing dental procedures. Predisposing cardiac condition was identified in 91 patients. Perioperative antimicrobial prophylaxis was administered to 67 patients. Staphylococcus aureus was the most frequent causative agent. Cardiac surgery was necessary in 85 patients (20 with prior dental and 65 with nondental procedure). Surgical mortality (12% vs 0%, P = .03) and hospital mortality (23% vs 3%, P = .001) were significantly larger among patients with nondental procedures. In a large unselected cohort of patients with IE, the incidence of preceding dental procedures was minimal. The number of cases potentially preventable by means of AP was negligible. Nondental procedures were more frequent than dental procedures and were correlated with poorer prognosis. Copyright © 2016 Elsevier Inc. All rights reserved.

Health care costs in the elderly in Germany: an analysis applying Andersen's behavioral model of health care utilization.

PubMed

Heider, Dirk; Matschinger, Herbert; Müller, Heiko; Saum, Kai-Uwe; Quinzler, Renate; Haefeli, Walter Emil; Wild, Beate; Lehnert, Thomas; Brenner, Hermann; König, Hans-Helmut

2014-02-14

To analyze the association of health care costs with predisposing, enabling, and need factors, as defined by Andersen's behavioral model of health care utilization, in the German elderly population. Using a cross-sectional design, cost data of 3,124 participants aged 57-84 years in the 8-year-follow-up of the ESTHER cohort study were analyzed. Health care utilization in a 3-month period was assessed retrospectively through an interview conducted by trained study physicians at respondents' homes. Unit costs were applied to calculate health care costs from the societal perspective. Socio-demographic and health-related variables were categorized as predisposing, enabling, or need factors as defined by the Andersen model. Multimorbidity was measured by the Cumulative Illness Rating Scale for Geriatrics (CIRS-G). Mental health status was measured by the SF-12 mental component summary (MCS) score. Sector-specific costs were analyzed by means of multiple Tobit regression models. Mean total costs per respondent were 889 € for the 3-month period. The CIRS-G score and the SF-12 MCS score representing the need factor in the Andersen model were consistently associated with total, inpatient, outpatient and nursing costs. Among the predisposing factors, age was positively associated with outpatient costs, nursing costs, and total costs, and the BMI was associated with outpatient costs. Multimorbidity and mental health status, both reflecting the need factor in the Andersen model, were the dominant predictors of health care costs. Predisposing and enabling factors had comparatively little impact on health care costs, possibly due to the characteristics of the German social health insurance system. Overall, the variables used in the Andersen model explained only little of the total variance in health care costs.

Nipple Pain Incidence, the Predisposing Factors, the Recovery Period After Care Management, and the Exclusive Breastfeeding Outcome.

PubMed

Puapornpong, Pawin; Paritakul, Panwara; Suksamarnwong, Maysita; Srisuwan, Siriwan; Ketsuwan, Sukwadee

2017-04-01

Nipple pain is the most common complaint of breastfeeding mothers during the immediate postpartum period. Persistent nipple pain is associated with low breastfeeding rate at 6 months postpartum. To further explore the incidence of nipple pain, associated predisposing factors, time for recovery after management, and the impact on exclusive breastfeeding rates. Included in this study were 1,649 singleton, pregnant women who delivered and had their 1-week follow-up at the breastfeeding clinic during the period of January 2013 to December 2015. The mothers who experienced nipple pain were analyzed for the incidence, the predisposing factors, and the recovery period after care management. The breastfeeding outcome comparison of both, mothers with and without pain, was measured by the exclusive breastfeeding rate at the sixth week postpartum. The incidence of nipple pain was at 9.6% by day 7. A predisposing factor of nipple pain was primiparity (relative risk = 1.8, 95% confidence interval 1.3-2.5). The reasons for nipple pain were inappropriate positioning and latching (72.3%), tongue-tie (23.2%), and oversupply (4.4%). The recovery period after care management was 1-2 weeks. There were no statistically significant differences between the 6-week exclusive breastfeeding rates of the mothers with nipple pain with treatment and the mothers without nipple pain. Persistent nipple pain was a common problem. The active management, including early detection and treatment, would help the mothers recover within a 2-week period and there was no significant difference of exclusive breastfeeding rates between the mothers who had early care management and the mothers without nipple pain.

Juvenile and adult-onset psychogenic non-epileptic seizures.

PubMed

Asadi-Pooya, Ali A; Emami, Mehrdad

2013-09-01

Psychogenic non-epileptic seizures (PNES) tend to begin in adolescence and young adulthood, although the seizures can occur in a wide range of ages. In the current study, we investigated the age of onset in patients with PNES and tried to determine the correlation between the age of onset and the demographic and clinical characteristics and factors potentially predisposing to PNES. In this cross-sectional study, all patients with a clinical diagnosis of PNES were recruited at the outpatient epilepsy clinic at Shiraz University of Medical Sciences from 2008 to 2012. We dichotomized the patients into two groups; those with age of onset below 18 years (juvenile), and those with age of onset at 18-55 years (adult-onset). We studied the demographic and clinical characteristics and factors potentially predisposing to PNES between these two groups. Statistical analyses were performed using Chi square and Fisher's Exact tests and Mann-Whitney U test. Fifty-seven patients with juvenile and 129 people with adult-onset PNES were studied. Demographic characteristics of these two groups were not different significantly. Seizure characteristics and semiology in these two groups were not significantly different either. However, factors potentially predisposing to PNES were significantly different between these two groups. History of being abused, academic failure, epilepsy or family history of epilepsy were more frequently observed in juvenile PNES, while medical comorbidities were more frequent among patients with adult-onset PNES. Age of onset of PNES is not correlated with the clinical manifestations; however, factors potentially predisposing to PNES are significantly different in patients with juvenile compared to those with adult-onset PNES. Copyright © 2013 Elsevier B.V. All rights reserved.

Two necrotic enteritis predisposing factors, dietary fishmeal and Eimeria infection, induce large changes in the caecal microbiota of broiler chickens.

PubMed

Wu, Shu-Biao; Stanley, Dragana; Rodgers, Nicholas; Swick, Robert A; Moore, Robert J

2014-03-14

It is widely established that a high-protein fishmeal supplemented starter diet and Eimeria infection can predispose birds to the development of clinical necrotic enteritis symptoms following Clostridium perfringens infection. However, it has not been clearly established what changes these treatments cause to predispose birds to succumb to necrotic enteritis. We analysed caecal microbiota of 4 groups of broilers (n=12) using deep pyrosequencing of 16S rDNA amplicons: (1) control chicks fed a control diet, (2) Eimeria infected chicks fed control diet, (3) chicks fed fishmeal supplemented diet and lastly (4) both fishmeal fed and Eimeria infected chicks. We found that the high-protein fishmeal diet had a strong effect on the intestinal microbiota similar to the previously reported effect of C. perfringens infection. We noted major changes in the prevalence of various lactobacilli while the total culturable Lactobacillus counts remained stable. The Ruminococcaceae, Lachnospiraceae, unknown Clostridiales and Lactobacillaceae families were most affected by fishmeal with increases in a number of operational taxonomic units (OTUs) that had previously been linked to Crohn's disease and reductions in OTUs known to be butyrate producers. Eimeria induced very different changes in microbiota; Ruminococcaceae groups were reduced in number and three unknown Clostridium species were increased in abundance. Additionally, Eimeria did not significantly influence changes in pH, formic, propionic or isobutyric acid while fishmeal induced dramatic changes in all these measures. Both fishmeal feeding and Eimeria infection induced significant changes in the gut microbiota; these changes may play an important role in predisposing birds to necrotic enteritis. Copyright © 2014 Elsevier B.V. All rights reserved.

A heuristic approach to the analysis of enzymic catalysis: reaction of delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-alpha-aminobutyrate and delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-allylglycine catalyzed by isopenicillin N synthase isozymes.

PubMed

Blackburn, J M; Sutherland, J D; Baldwin, J E

1995-06-06

Isopenicillin N synthase (IPNS) catalyzes the oxidative cyclization of delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine to isopenicillin N. It is proposed that the multiple products produced from certain substrate analogues result from pathway branching after formation of a ferryl oxene intermediate. We have been interested in ascertaining the reasons for multiple product formation. One possibility is that the products are predisposed toward formation once the beta-lactam ring and the ferryl oxene are produced. Alternately, the products may be persuaded into being by the enzyme restricting conformations such that otherwise less favorable chemistry can take place. With the existing description of the IPNS catalytic cycle, this fundamental question has not been answerable. We describe here the application of a heuristic method to resolve this key issue. It was reasoned that by comparing the ratios of products formed by a set of perturbed IPNS variants it might be possible to generate qualitative information about the relative magnitude of certain activation parameters. If certain product ratios are affected but others are not, then it should be possible to say which steps in the reaction are dictated merely by chemical fundamentals and which steps are directly effected by the enzyme. In this paper we report the high-level expression, purification, and characterization of four IPNS isozymes. Comparison of the product ratios obtained on incubation of unnatural substrate analogues with four IPNS isozymes corresponding to perturbed active site variants shows substantial variation in some cases and little in others. Interpretation of the results obtained with delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-alpha-aminobutyrate (ACAB) allows conclusions to be drawn regarding the role of the enzyme in restricting available conformations of the natural substrate to disfavor certain otherwise chemically favorable pathways and hence products. The results obtained with delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-allylglycine, while rather more complex, substantiate the conclusions drawn from the ACAB data. A major conclusion is that, in the oxidation of ACV, IPNS is a negative catalyst of cepham formation but a positive catalyst of penam formation.

Self-organization at the frictional interface for green tribology.

PubMed

Nosonovsky, Michael

2010-10-28

Despite the fact that self-organization during friction has received relatively little attention from tribologists so far, it has the potential for the creation of self-healing and self-lubricating materials, which are important for green or environment-friendly tribology. The principles of the thermodynamics of irreversible processes and of the nonlinear theory of dynamical systems are used to investigate the formation of spatial and temporal structures during friction. The transition to the self-organized state with low friction and wear occurs through destabilization of steady-state (stationary) sliding. The criterion for destabilization is formulated and several examples are discussed: the formation of a protective film, microtopography evolution and slip waves. The pattern formation may involve self-organized criticality and reaction-diffusion systems. A special self-healing mechanism may be embedded into the material by coupling the corresponding required forces. The analysis provides the structure-property relationship, which can be applied for the design optimization of composite self-lubricating and self-healing materials for various ecologically friendly applications and green tribology.

Transformation of humus substances in the long-drained surface-gleyed soddy-podzolic soils under conditions of pronounced microrelief and different agrogenic loads

NASA Astrophysics Data System (ADS)

Ovchinnikova, M. F.

2016-08-01

The transformation of humus substances resulting from artificial drainage of the surface-gleyed soddy-podzolic soils under conditions of pronounced microtopography and different agrogenic loads was studied. The studied soil characteristics included acid-base conditions, the content and group composition of humus, the ratios between the fractions of humus acids, and optical density of humic acids. The features attesting to humus degradation were found in the soils of microdepressions periodically subjected to excessive surface moistening, in the soils of different landforms upon the construction of drainage trenches, and in the plowed non-fertilized soils. The response of humus characteristics to the changes in the ecological situation in the period of active application of agrochemicals for reclamation of the agrotechnogenically disturbed soils was traced. It was shown that the long-term dynamics of the particular parameters of the biological productivity of the soil depend on the hydrological and agrogenic factors, as well as on the weather conditions.

Typical Applications of Airborne LIDAR Technolagy in Geological Investigation

NASA Astrophysics Data System (ADS)

Zheng, X.; Xiao, C.

2018-05-01

The technology of airborne light detection and ranging (LiDAR), also referred to as Airborne Laser Scanning, is widely used for high-resolution topographic data acquisition (even under forest cover) with sub-meter planimetric and vertical accuracy. This contribution constructs the real digital terrain model to provide the direct observation data for the landscape analysis in geological domains. Based on the advantage of LiDAR, the authors mainly deal with the applications of LiDAR data to such fields as surface land collapse, landslide and fault structure extraction. The review conclusion shows that airborne LiDAR technology is becoming an indispensable tool for above mentioned issues, especially in the local and large scale investigations of micro-topography. The technology not only can identify the surface collapse, landslide boundary and subtle faulted landform, but also be able to extract the filling parameters of collapsed surface, the geomorphic parameters of landslide stability evaluation and cracks. This technology has extensive prospect of applications in geological investigation.

Hydrologic modeling to screen potential environmental management methods for malaria vector control in Niger

NASA Astrophysics Data System (ADS)

Gianotti, Rebecca L.; Bomblies, Arne; Eltahir, Elfatih A. B.

2009-08-01

This paper describes the first use of Hydrology-Entomology and Malaria Transmission Simulator (HYDREMATS), a physically based distributed hydrology model, to investigate environmental management methods for malaria vector control in the Sahelian village of Banizoumbou, Niger. The investigation showed that leveling of topographic depressions where temporary breeding habitats form during the rainy season, by altering pool basin microtopography, could reduce the pool persistence time to less than the time needed for establishment of mosquito breeding, approximately 7 days. Undertaking soil surface plowing can also reduce pool persistence time by increasing the infiltration rate through an existing pool basin. Reduction of the pool persistence time to less than the rainfall interstorm period increases the frequency of pool drying events, removing habitat for subadult mosquitoes. Both management approaches could potentially be considered within a given context. This investigation demonstrates that management methods that modify the hydrologic environment have significant potential to contribute to malaria vector control in water-limited, Sahelian Africa.

Relationship of Optical Anomalies, Zoning, and Microtopography in Vesuvianite from Jeffrey Mine, Asbestos, Quebec

NASA Astrophysics Data System (ADS)

Smith, Varina Campbell

The role of growth steps in inducing disequilibrium is investigated in crystals of vesuvianite from the Jeffrey mine, Asbestos, Quebec, using optical microscopy, atomic force microscopy, electron microprobe analysis, and single-crystal X-ray diffraction. The selective uptake of elements Fe and Al by asymmetric growth-steps on three crystallographic forms, {100}, {110}, and {121}, is documented. The prisms {100} and {110} show hillocks that display kinetically controlled oscillatory zoning along growth steps parallel to <010> and <11¯1>, but not on vicinal faces defined by [001] steps. Sector-specific zoning of extinction angles and 2V angles indicate different degrees of optical dissymmetrization in crystals spanning a range of growth habits. Unit-cell parameters and the presence of violating reflections confirm sectoral deviations from P4/nnc symmetry in the prismatic sectors. The partial loss of three glide planes follows the pattern expected from order of the cations Al and Fe induced by tangential selectivity at the edge of non-equivalent steps during layer-by-layer growth.

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

Jones, Benjamin M.; Grosse, Guido; Arp, Christopher D.

Fire-induced permafrost degradation is well documented in boreal forests, but the role of fires in initiating thermokarst development in Arctic tundra is less well understood. Here we show that Arctic tundra fires may induce widespread thaw subsidence of permafrost terrain in the first seven years following the disturbance. Quantitative analysis of airborne LiDAR data acquired two and seven years post-fire, detected permafrost thaw subsidence across 34% of the burned tundra area studied, compared to less than 1% in similar undisturbed, ice-rich tundra terrain units. The variability in thermokarst development appears to be influenced by the interaction of tundra fire burnmore » severity and near-surface, ground-ice content. Subsidence was greatest in severely burned, ice-rich upland terrain (yedoma), accounting for -50% of the detected subsidence, despite representing only 30% of the fire disturbed study area. Microtopography increased by 340% in this terrain unit as a result of ice wedge degradation. Increases in the frequency, magnitude, and severity of tundra fires will contribute to future thermokarst development and associated landscape change in Arctic tundra regions.« less

Chemical defence in mussels: antifouling effect of crude extracts of the periostracum of the blue mussel Mytilus edulis.

PubMed

Bers, A Valeria; D'Souza, Fraddry; Klijnstra, Job W; Willemsen, Peter R; Wahl, Martin

2006-01-01

Shells of the blue mussel Mytilus edulis remain free of fouling organisms as long as they possess an intact periostracum, and a multiple antifouling defence that comprises a ripple-like microtopography and the production of chemical antifouling compounds has been suggested previously. This study investigates the chemical defence strategy of blue mussels for the first time. Six crude extracts of the periostracum of intact shells were made using solvents of increasing polarity. These extracts were tested against common fouling organisms in laboratory based bioassays. Non-polar and moderately polar fractions showed the highest activities: the diethyl ether fraction strongly inhibited attachment of Balanus amphitrite cyprids and the marine bacteria Cobetia marina and Marinobacter hydrocarbonoclasticus. Attachment of the benthic diatom Amphora coffeaeformis was significantly reduced by the dichloromethane extract, whereas both ethyl acetate and diethyl ether fractions slowed diatom growth. These results provide the first evidence of surface bound compounds that may moderate surface colonisation.

Gout: a review of non-modifiable and modifiable risk factors

PubMed Central

MacFarlane, Lindsey A.; Kim, Seoyoung C.

2014-01-01

Gout is a common inflammatory arthritis triggered by the crystallization of uric acid within the joints. Gout affects millions worldwide and has an increasing prevalence. Recent research has been carried out to better qualify and quantify the risk factors predisposing individuals to gout. These can largely be broken into non-modifiable risk factors such as sex, age, race, and genetics, and modifiable risk factors such as diet and lifestyle. Increasing knowledge of factors predisposing certain individuals to gout could potentially lead to improved preventive practices. This review summarizes the non-modifiable and modifiable risk factors associated with development of gout. PMID:25437279

Dietary copper: a novel predisposing factor for oral submucous fibrosis?

PubMed

Arakeri, Gururaj; Brennan, Peter A

2013-03-01

Oral submucous fibrosis (OSMF) is known devastating disorder commonly seen in South Asian developing countries. It is directly linked to areca nut chewing and the contents of areca are subjected to multitude of investigations. Among all the contents of areca nut, the copper element has been extensively studied. Most of the published studies have validated its association with OSMF because of its local action. In this paper we postulate a novel biological pathway through which copper is thought to predispose oral mucosa to OSMF. The hypothesis is instructive in explaining various unexplored aspects of the disease. Copyright © 2012 Elsevier Ltd. All rights reserved.

Bilateral breast abscess: a rare complication of enteric fever.

PubMed

Singh, S; Pandya, Y; Rathod, J; Trivedi, S

2009-01-01

Breast abscess is usually caused by Staphylococcus aureus in pregnant or lactating females. Salmonella spp. is occasionally associated with abscess formation in various organs, but breast abscess is a very rare complication. In enteric fever dissemination to multiple organ systems following bacteraemia can lead to localized abscess. We report a case of bilateral breast abscess due to Salmonella Typhi in an unmarried 35-year-old female without any predisposing conditions. She presented with fever and painful swelling of both the breasts. S. typhi was isolated from both breasts. Such rare cause must be suspected in females without any evident predisposing factors for effective management.

Formal Home Care Utilization Patterns by Rural–Urban Community Residence

PubMed Central

Spector, William; Van Nostrand, Joan

2009-01-01

Background We examined formal home care utilization among civilian adults across metro and nonmetro residential categories before and after adjustment for predisposing, enabling, and need variables. Methods Two years of the Medical Expenditure Panel Survey (MEPS) were combined to produce a nationally representative sample of adults who resided in the community for a calendar year. We established 6 rural–urban categories based upon Urban Influence Codes and examined 2 dependent variables: (a) likelihood of using any formal home care and (b) number of provider days received by users. The Area Resource File provided county-level information. Logistic and negative binomial regression analyses were employed, with adjustments for the MEPS complex sampling design and the combined years. Results Under controls for predisposing, enabling, and need variables, differences in likelihood of any formal home care use disappear, but differences in number of provider days received by users emerged, with fewer provider days in remote areas than in metro and several other nonmetro types. Conclusions It is important to fully account for predisposing, enabling, and need factors when assessing rural and urban home care utilization patterns. The limited provider days in remote counties under controls suggest a possible access problem for adults in these areas. PMID:19196690

Incidence and predisposing factors of phlebitis in a surgery department.

PubMed

Rego Furtado, Luís Carlos do

This paper reports on a study conducted to determine the incidence of phlebitis related to peripheral cannulae, and its predisposing factors in a general surgery department. Phlebitis is a serious health problem that affects a large proportion of hospitalized patients receiving intravenous therapy. A data collection tool was developed based on the previous literature and was completed between 15 October and 30 November 2010 in a general surgery department. All patients with peripheral cannulae who fulfilled the inclusion criteria, and who agreed to participate in the study where monitored. This was a quantitative study, which used descriptive, inferential, and correlational analysis. A total of 171 patients and 286 peripheral cannulae were monitored. The average incidence of phlebitis was 61.5%, and factors such as diabetes and tobacco consumption were identified as relevant to the development of phlebitis. Other elements identified as predisposing to the development of phlebitis include administration of potassium chloride, the dwell time of the peripheral cannula, and the anatomical location of the cannula. Phlebitis associated with peripheral cannulae is still a current problem requiring knowledgeable staff who can prevent, recognize and act appropriately in a timely manner to minimize its severity.

Expediting support for the pregnant mothers to obtain antenatal care at public health facilities in rural areas of Balochistan province, Pakistan

PubMed Central

Ghaffar, Abdul; Pongpanich, Sathirakorn; Ghaffar, Najma; Chapman, Robert Sedgwick; Mureed, Sheh

2015-01-01

Objectives: To identify, and compare relative importance of, factors associated with antenatal care (ANC) utilization in rural Balochistan, toward framing a policy to increase such utilization. Methods: This cross sectional study was conducted among 513 pregnant women in Jhal Magsi District, Balochistan, in 2011. A standardized interviewer-administered questionnaire was used. Predisposing, enabling, and reinforcing factors were evaluated with generalized linear models (Poisson distribution and log link). Results: Prevalence of any ANC was only 14.4%. Predisposing, enabling, and reinforcing factors were all important determinants of ANC utilization. Reinforcing factors were clearly most important, husband’s support for ANC was more important than support from other community members. Among predisposing factors, higher income, education, occupation, and better knowledge regarding benefits of ANC were positively and statistically significantly associated with ANC However increased number of children showed negative association. Complications free pregnancy showed positive significant association with ANC at public health facility among enabling factors. Conclusion: It is very important to increase antenatal care utilization in the study area and similar areas. Policy to achieve this should focus on enhancing support from the husband. PMID:26150867

Recurrent candidal intertrigo: challenges and solutions

PubMed Central

Metin, Ahmet; Dilek, Nursel; Bilgili, Serap Gunes

2018-01-01

Intertrigo is a common inflammatory dermatosis of opposing skin surfaces that can be caused by a variety of infectious agents, most notably candida, under the effect of mechanical and environmental factors. Symptoms such as pain and itching significantly decrease quality of life, leading to high morbidity. A multitude of predisposing factors, particularly obesity, diabetes mellitus, and immunosuppressive conditions facilitate both the occurrence and recurrence of the disease. The diagnosis of candidal intertrigo is usually based on clinical appearance. However, a range of laboratory studies from simple tests to advanced methods can be carried out to confirm the diagnosis. Such tests are especially useful in treatment-resistant or recurrent cases for establishing a differential diagnosis. The first and key step of management is identification and correction of predisposing factors. Patients should be encouraged to lose weight, followed up properly after endocrinologic treatment and intestinal colonization or periorificial infections should be medically managed, especially in recurrent and resistant cases. Medical treatment of candidal intertrigo usually requires topical administration of nystatin and azole group antifungals. In this context, it is also possible to use magistral remedies safely and effectively. In case of predisposing immunosuppressive conditions or generalized infections, novel systemic agents with higher potency may be required. PMID:29713190

The role of anxiety in vaginismus: a case-control study.

PubMed

Watts, Gayle; Nettle, Daniel

2010-01-01

Previous research suggests that anxiety may play a large role in the symptoms of vaginismus. We aimed to (i) determine the degree of self-reported general anxiety in women with vaginismus; and (ii) establish whether general anxiety is a consequence of the condition or a predisposing factor. Participants reported state and trait anxiety, five-factor personality scores, history of anxiety disorders, and their perceptions of their symptoms and history. We compared responses of 244 self-identified women with vaginismus with a control group of 101 women using an online questionnaire. The women with vaginismus were higher in trait anxiety and neuroticism, and lower in extraversion, than the controls. There was also a trend toward a greater prevalence of diagnosed anxiety disorders in the vaginismus group. Levels of state anxiety were high among the women with vaginismus, particularly when they felt unsupported by their partners or pressured to cure the condition. Levels of general anxiety are elevated among women with vaginismus and the data suggest that anxiety-proneness may be a predisposing factor for the condition. We conclude that although vaginismus is a multidimensional condition, it may have common predisposing factors with anxiety disorders.

Association between alterations in global DNA methylation and predisposing factors in diabetes: a high pressure liquid chromatography based study.

PubMed

Maghbooli, Z; Hossein-Nezhad, A; Larijani, B; Pasalar, P; Keshtkar, A A

2015-08-01

The aim of this study was to investigate the relationship between inter-individual global DNA methylation and diabetes predisposing factors. The 5-methyl cytosine content was assessed by reverse phase high pressure liquid chromatography (RP-HPLC) of peripheral blood leukocytes obtained from 178 type 2 diabetes patients to determine individual global DNA methylation status. There was a positive significant correlation between diabetes duration and DNA methylation levels (P=0.002) with increasing levels of DNA methylation associated with age (P=0.047). There was no significant correlation between DNA methylation levels and HbA1c (P=0.15). No significant differences were observed between patients with and without diabetes predisposing factors including: hypertension (P=0.772), dyslipidemia (P=0.617), insulin resistance (homeostatic model assessment index) (P=0.156) and obesity (P=0.609). As such, the duration of diabetes (>10 years) was the most important predictor of global DNA methylation levels in diabetic patients after adjusting for age and sex (P=0.023). Our findings indicate that chronic hyperglycemic exposure plays an independent role in global DNA methylation levels in type 2 diabetes patients.

Study of Pre-disposing Factors of Acute Exacerbation of Chronic Obstructive Pulmonary Disease and Antibiotic Prescribing Pattern with Reference to Antibiotic Sensitivity Test.

PubMed

Shrestha, R; Shrestha, B; Shakya Shrestha, S; Pant, A; Prajapati, B; Karmacharya, B M

2015-01-01

Background Chronic Obstructive Pulmonary Disease (COPD) affects about 329 million people worldwide, which is nearly 5% of the entire global population. In the context of Nepal, COPD accounts for 43% of the non-communicable disease burden and 2.56% of hospitalizations. Various pre-disposing factors like bacterial, viral, fungal, smoking, occupational exposures and genetic factors have been proposed to precipitate COPD and its exacerbation though, the definitive pre-disposing factors and factors related to acute exacerbation have not been determined in the context of Nepal. Objective To find out the pre-disposing factors and the related causative agents for COPD. Method A cross sectional study was conducted in a tertiary care hospital. Patients of all age group who were diagnosed as COPD and admitted in the hospital were included in this study. Patients were interviewed using structured questionnaire. The sociodemographic data including personal and medical history were recorded from those participants. In addition, sputum from those patients was sent for culture to investigate the possible responsible pathogens as well as its antibiotic sensitivity pattern. Result A total of 150 patients having Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD) who have admitted from either emergency or out-patient department of the hospital were included in this study. Among the total number of patients, more than half of them were female (n=82). In addition, analysis of occupations shows that most of them were either farmer (36.0%) or housewife (30.7%). In total studied patients (n=150), most of them were using traditional firewood (83%) for cooking purpose and majority of patients (91%) were smokers. Most of the sputum samples show growth of gram-positive cocci (26.7%) and gram negative bacilli (27.5%). Considering the overall sensitivity pattern, the higher sensitivity was recorded for Co-trimoxazole and Ciprofloxacin while higher rate of resistance was noted for Penicillin group of drugs. The most widely used antibiotics were found to be Cephalosporin group of drugs (68%). Conclusion The present study revealed that the case of COPD is more in female and the commonest pre-disposing factor is found to be smoke/firewood. Cephalosporin group of drugs is the most commonly prescribed drug.

Monoamine oxidase-A physically interacts with presenilin-1(M146V) in the mouse cortex.

PubMed

Wei, Zelan; Gabriel, Geraldine G; Rui, Lewei; Cao, Xia; Pennington, Paul R; Chlan-Fourney, Jennifer; Nazarali, Adil J; Baker, Glen B; Mousseau, Darrell D

2012-01-01

The concentration of presenilin-1 (PS-1) protein at the mitochondrial-associated aspect of the endoplasmic reticulum supports the potential for a mitochondrial influence of PS-1. Given that carriers of certain Alzheimer's disease (AD)-related PS-1 variants are predisposed to clinical depression and that depression has been historically associated with the mitochondrial enzyme, monoamine oxidase-A (MAO-A), we investigated cortical MAO-A function in the AD-related PS-1(M146V) knock-in mouse. The MAO-A system was clearly altered in the PS-1(M146V) mouse as revealed by (a) a mismatch between MAO-A protein expression and MAO-A activity; (b) changes in MAO-A-mediated monoaminergic neurotransmitter metabolism; (c) changes in non-cognitive behavior following treatment with the irreversible MAO-A inhibitor clorgyline; and (d) an increase in the potency of clorgyline in these same mice. We next investigated whether PS-1(M146V) could be influencing MAO-A directly. We observed (a) an enhanced MAO-A activity in necropsied PS-1(M146V) mouse cortical extracts incubated with DAPT (a PS-1 substrate-competitor); (b) the proximity of PS-1 with MAO-A and mitochondrial markers in cortical sections and in primary cortical neurons; (c) the co-segregation and co-immunoprecipitation of PS-1 and MAO-A within the mitochondrial fraction; and (d) the co-immunoprecipitation of overexpressed PS-1(M146V) and MAO-A proteins from N2a lysates. The PS-1(ΔEx9) and PS-1(D257A) variants, known to have low substrate-binding capacity, co-immunoprecipitated weakly with MAO-A. These combined data support a physical interaction between PS-1 and MAO-A that could influence MAO-A activity and contribute to the monoaminergic disruptions common to disorders as seemingly diverse as depression and AD.

Effects of Small-scale Vegetation-related Roughness on Overland Flow and Infiltration in Semi-arid Grassland and Shrublands

NASA Astrophysics Data System (ADS)

Bedford, D.

2012-12-01

We studied the effects of small-scale roughness on overland flow/runoff and the spatial pattern of infiltration. Our semi-arid sites include a grassland and shrubland in Central New Mexico and a shrubland in the Eastern Mojave Desert. Vegetation exerts strong controls on small-scale surface roughness in the form of plant mounds and other microtopography such as depressions and rills. We quantified the effects of densely measured soil surface heterogeneity using model simulations of runoff and infiltration. Microtopographic roughness associated with vegetation patterns, on the scale of mm-cm's in height, has a larger effect on runoff and infiltration than spatially correlated saturated conductivity. The magnitude and pattern of the effect of roughness largely depends on the vegetation and landform type, and rainfall depth and intensity. In all cases, runoff and infiltration amount and patterns were most strongly affected by depression storage. In the grassland we studied in central New Mexico, soil surface roughness had a large effect on runoff and infiltration where vegetation mounds coalesced, forming large storage volumes that require filling and overtopping in order for overland flow to concentrate into runoff. Total discharge over rough surfaces was reduced 100-200% compared to simulations in which no surface roughness was accounted for. For shrublands, total discharge was reduced 30-40% by microtopography on gently sloping alluvial fans and only 10-20% on steep hillslopes. This difference is largely due to the lack of storage elements on steep slopes. For our sites, we found that overland flow can increase infiltration by up to 2.5 times the total rainfall by filling depressions. The redistribution of water via overland flow can affect up to 20% of an area but varies with vegetation type and landform. This infiltration augmentation by overland flow tends to occur near the edges of vegetation canopies where overland flow depths are deep and infiltration rates are moderate. Infiltration augmentation is greatest in microtopographic depressions and flow threads. These results show that some vegetation-landform settings are efficient at trapping and concentrating the primary limiting resource, and demonstrate the importance of micro-scale soil characteristics for the ecohydrologic function of semi-arid environments. Since other essential attributes for plant ecosystems, such as nutrients, likely co-vary with water availability, further research is needed to elucidate ecosystem dynamics that may lead to self-organized behavior and determine thresholds for ecosystem stability.

Spatial variation in below ground carbon cycling in a pristine peatland, driven by present and past vegetation

NASA Astrophysics Data System (ADS)

Mathijssen, Paul; Knorr, Klaus-Holger; Gałka, Mariusz; Borken, Werner

2017-04-01

Peat carbon cycling is controlled by both large scale factors, such as climate and hydrological setting, and small scale factors, such as microtopography, vegetation, litter quality, and rooting depth. These small scale factors commonly vary within peatlands, causing variation in the carbon balance at different locations within the same site. Understanding the relationship between small scale carbon cycling and vegetation helps us to assess the variation of carbon dynamics of peatlands, because vegetation composition acts as an integrator of factors such as microtopography, hydrology, and nutrient level. Variation in vegetation illustrates spatial variation of these underlying factors. Furthermore, the presence of certain plant species affects carbon cycling directly through litter quality or aeration through root tissues. In order to understand these within-site variations in terms of carbon cycling, we investigated carbon accumulation, decomposition, and biogeochemistry of pore waters along a transect of peat cores with changing vegetation and water levels in an ombrotrophic peatland in southern Patagonia. The transect ran from a Sphagnum magellanicum dominated spot with relatively high water table, to intermediately wet spots with mixed Sphagnum/shrubs vegetation, or dominated by Cyperaceae, eventually to a more elevated and drier spot dominated by cushion plants (mainly Astelia pumila). There were large differences in peat accumulation rates and peat densities, with faster peat growth and lower densities under Sphagnum, but overall carbon accumulation rates were quite similar in the various microenvironments. At most plots C/N ratios decreased with depth, concurrent with increasing humification index derived from FT-IR spectra. But under cushion plants this relation was opposite: more humification with depth, but also C/N ratios increases. This reflected the differing source material at depth under the cushion plants, and that the cushion plant peat layers were formed on top of Sphagnum peat. The divergent source material throughout a peat core makes it difficult to use C/N ratios to indicate peat decomposition rates. Although the low peat density and higher C/N ratios indicate that overall carbon turnover is slow at Sphagnum plots, pore water methane concentrations were elevated. At cushion plant plots, however, higher redox potentials exist until greater depths due to aerenchymous roots, inhibiting methane production and release. Our results demonstrate that large variation exists within pristine bogs, in terms of decomposition patterns, organic matter quality, and carbon turnover pathways, corresponding to variation in surface moisture levels and vegetation. Furthermore, variation in carbon cycling properties are maintained in buried peat layers and reflect more the organic material of that layer, than the current surface carbon dynamics.

Influence of micro-topography and crown characteristics on tree height estimations in tropical forests based on LiDAR canopy height models

NASA Astrophysics Data System (ADS)

Alexander, Cici; Korstjens, Amanda H.; Hill, Ross A.

2018-03-01

Tree or canopy height is an important attribute for carbon stock estimation, forest management and habitat quality assessment. Airborne Laser Scanning (ALS) based on Light Detection and Ranging (LiDAR) has advantages over other remote sensing techniques for describing the structure of forests. However, sloped terrain can be challenging for accurate estimation of tree locations and heights based on a Canopy Height Model (CHM) generated from ALS data; a CHM is a height-normalised Digital Surface Model (DSM) obtained by subtracting a Digital Terrain Model (DTM) from a DSM. On sloped terrain, points at the same elevation on a tree crown appear to increase in height in the downhill direction, based on the ground elevations at these points. A point will be incorrectly identified as the treetop by individual tree crown (ITC) recognition algorithms if its height is greater than that of the actual treetop in the CHM, which will be recorded as the tree height. In this study, the influence of terrain slope and crown characteristics on the detection of treetops and estimation of tree heights is assessed using ALS data in a tropical forest with complex terrain (i.e. micro-topography) and tree crown characteristics. Locations and heights of 11,442 trees based on a DSM are compared with those based on a CHM. The horizontal (DH) and vertical displacements (DV) increase with terrain slope (r = 0.47 and r = 0.54 respectively, p < 0.001). The overestimations in tree height are up to 16.6 m on slopes greater than 50° in our study area in Sumatra. The errors in locations (DH) and tree heights (DV) are modelled for trees with conical and spherical tree crowns. For a spherical tree crown, DH can be modelled as R sin θ, and DV as R (sec θ - 1). In this study, a model is developed for an idealised conical tree crown, DV = R (tan θ - tan ψ), where R is the crown radius, and θ and ψ are terrain and crown angles respectively. It is shown that errors occur only when terrain angle exceeds the crown angle, with the horizontal displacement equal to the crown radius. Errors in location are seen to be greater for spherical than conical trees on slopes where crown angles of conical trees are less than the terrain angle. The results are especially relevant for biomass and carbon stock estimations in tropical forests where there are trees with large crown radii on slopes.

What aspects of autism predispose to talent?

PubMed Central

Happé, Francesca; Vital, Pedro

2009-01-01

In this paper, we explore the question, why are striking special skills so much more common in autism spectrum conditions (ASC) than in other groups? Current cognitive accounts of ASC are briefly reviewed in relation to special skills. Difficulties in ‘theory of mind’ may contribute to originality in ASC, since individuals who do not automatically ‘read other minds’ may be better able to think outside prevailing fashions and popular theories. However, originality alone does not confer talent. Executive dysfunction has been suggested as the ‘releasing’ mechanism for special skills in ASC, but other groups with executive difficulties do not show raised incidence of talents. Detail-focused processing bias (‘weak coherence’, ‘enhanced perceptual functioning’) appears to be the most promising predisposing characteristic, or ‘starting engine’, for talent development. In support of this notion, we summarize data from a population-based twin study in which parents reported on their 8-year-olds' talents and their ASC-like traits. Across the whole sample, ASC-like traits, and specifically ‘restricted and repetitive behaviours and interests’ related to detail focus, were more pronounced in children reported to have talents outstripping older children. We suggest that detail-focused cognitive style predisposes to talent in savant domains in, and beyond, autism spectrum disorders. PMID:19528019

The Association of Birth Complications and Externalizing Behavior in Early Adolescents: Direct and Mediating Effects

PubMed Central

Liu, Jianghong; Raine, Adrian; Wuerker, Anne; Venables, Peter H.; Mednick, Sarnoff

2012-01-01

Prior studies have shown that birth complications interact with psychosocial risk factors in predisposing to increased externalizing behavior in childhood and criminal behavior in adulthood. However, little is known about the direct relationship between birth complications and externalizing behavior. Furthermore, the mechanism by which the birth complications predispose to externalizing behavior is not well explored. This study aims to assess whether birth complications predispose to early adolescent externalizing behavior and to test whether Intelligence Quotient (IQ) mediates relationships between predictor and outcome variables. We used data from a prospective, longitudinal birth cohort of 1,795 3-year-old boys and girls from Mauritius to test hypotheses. Birth complications were assessed from hospital record data, malnutrition from a pediatric exam at age 3 years, psychosocial adversity from parental interviews at age 3 years, and externalizing behavior problems from parental ratings at age 11 years. We found that babies with birth complications are more likely to develop externalizing behavior problems at age 11. Low IQ was associated with birth complications and was found to mediate the link between early predictors and later externalizing behavior. These prospective, longitudinal findings have potential clinical implications for the identification of early adolescent externalizing behavior and for public health attempts to prevent the occurrence of child externalizing behavior problems. PMID:22485069

Influenza A Virus as a Predisposing Factor for Cryptococcosis

PubMed Central

Oliveira, Lorena V. N.; Costa, Marliete C.; Magalhães, Thaís F. F.; Bastos, Rafael W.; Santos, Patrícia C.; Carneiro, Hellem C. S.; Ribeiro, Noelly Q.; Ferreira, Gabriella F.; Ribeiro, Lucas S.; Gonçalves, Ana P. F.; Fagundes, Caio T.; Pascoal-Xavier, Marcelo A.; Djordjevic, Julianne T.; Sorrell, Tania C.; Souza, Daniele G.; Machado, Alexandre M. V.; Santos, Daniel A.

2017-01-01

Influenza A virus (IAV) infects millions of people annually and predisposes to secondary bacterial infections. Inhalation of fungi within the Cryptococcus complex causes pulmonary disease with secondary meningo-encephalitis. Underlying pulmonary disease is a strong risk factor for development of C. gattii cryptococcosis though the effect of concurrent infection with IAV has not been studied. We developed an in vivo model of Influenza A H1N1 and C. gattii co-infection. Co-infection resulted in a major increase in morbidity and mortality, with severe lung damage and a high brain fungal burden when mice were infected in the acute phase of influenza multiplication. Furthermore, IAV alters the host response to C. gattii, leading to recruitment of significantly more neutrophils and macrophages into the lungs. Moreover, IAV induced the production of type 1 interferons (IFN-α4/β) and the levels of IFN-γ were significantly reduced, which can be associated with impairment of the immune response to Cryptococcus during co-infection. Phagocytosis, killing of cryptococci and production of reactive oxygen species (ROS) by IAV-infected macrophages were reduced, independent of previous IFN-γ stimulation, leading to increased proliferation of the fungus within macrophages. In conclusion, IAV infection is a predisposing factor for severe disease and adverse outcomes in mice co-infected with C. gattii. PMID:29018774

Post spinal puncture headache, an old problem and new concepts: review of articles about predisposing factors

PubMed Central

Jabbari, Ali; Alijanpour, Ebrahim; Mir, Mehrafza; Bani hashem, Nadia; Rabiea, Seyed Mozaffar; Rupani, Mohammad Ali

2013-01-01

Post spinal puncture headache (PSPH) is a well known complication of spinal anesthesia. It occurs after spinal anesthesia induction due to dural and arachnoid puncture and has a significant effect on the patient’s postoperative well being. This manuscript is based on an observational study that runs on Babol University of Medical Sciences and review of literatures about current concepts about the incidence, risk factors and predisposing factors of post spinal puncture headache. The overall incidence of post-dural puncture headache after intentional dural puncture varies form 0.1-36%, while it is about 3.1% by atraumatic spinal needle 25G Whitacre. 25G Quincke needle with a medium bevel cutting is popular with widespread use and the incidence of PSPH is about 25%, but its incidence obtained 17.3% by spinal needle 25G Quincke in our observation. The association of predisposing factors like female, young age, pregnancy, low body mass index, multiple dural puncture, inexpert operators and past medical history of chronic headache, expose the patient to PSPH. The identification of factors that predict the likelihood of PSPH is important so that measures can be taken to minimize this painful complication resulting from spinal anesthesia. PMID:24009943

Cemental tear: To know what we have neglected in dental practice.

PubMed

Jeng, Po-Yuan; Luzi, Arlinda Luzi; Pitarch, Rocio Marco; Chang, Mei-Chi; Wu, Yu-Hsueh; Jeng, Jiiang-Huei

2018-04-01

Cemental tear is a special kind of root surface fracture, contributing to periodontal and periapical breakdown. However, it is a challenge for doctors to diagnose, resulting in delayed or improper treatment. We reviewed the predisposing factors, location, radiographic/clinical characteristics, diagnosis and treatments of cemental tears. From the literature, patients with cemental tear were mainly males, over 60 year-old. Possible predisposing factors include gender, age, tooth type, traumatic occlusal force and vital teeth. Cemental tears were common in upper and lower anterior teeth, single or multiple, and can be present in cervical, middle and apical third of roots. Morphology of cemental tears can be either piece-shaped or U-shaped. Clinically, cemental tear shows a unitary periodontal pocket and signs/symptoms mimicking localized periodontitis, apical periodontitis and vertical root fractures. Treatment of cemental tears include scaling, root planning, root canal treatment, periodontal/periapical surgery, guided tissue regeneration, bone grafting, and intentional replantation. Recurrence of cemental tear is possible especially when the fracture involves root apex. Extraction is recommended for teeth with poor prognosis. In conclusion, cemental tears can involve both periodontal and periapical area. Dentists should understand the predisposing factors and clinical features of cemental tears for early diagnosis/treatment to prevent bone loss/tooth extraction. Copyright © 2017. Published by Elsevier B.V.

Assessing the significance of health information seeking in chronic condition management.

PubMed

Dean, Caress A; Geneus, Christian J; Rice, Shahida; Johns, Marquisha; Quasie-Woode, Delores; Broom, Kevin; Elder, Keith

2017-08-01

To examine the relationship between health information seeking and confidence in performing self-management activities, and to assess the influence of predisposing, enabling, and perceive need factors on confidence to perform self-management activities among adults with chronic conditions. The sample included 6724 adults from the 2007 Health Tracking Household Survey who were ≥18 years with a chronic condition. Binary logistic regression examined the relationship between health information seeking, predisposing, enabling, and perceive need factors and confidence in performing three self-management activities; prevent symptoms, tell doctor concerns, and know when to get medical care. Analyses indicated that 63.7% of adults sought health information. Rural residents who sought health information had 50% (95% CI: 0.28-0.89) lower odds of being confident to tell doctor concerns compared to urban residents who did not seek health information. The relationship between health information seeking and confidence to perform self-management varies by self-management activity. Rurality, education level, having a usual source of care, and perceived health status strongly predict confidence to perform self-management activities. Self-management strategies should incorporate health information seeking behavior that will enhance confidence to perform specific self-management activities, and should incorporate predisposing, enabling, and perceive need factors. Copyright © 2017 Elsevier B.V. All rights reserved.

A content analysis of precede-proceed constructs in stress management mobile apps

PubMed Central

Wilkinson, Jessica; West, Joshua H.; Bernhardt, Jay M.

2016-01-01

Background The emergence of Apple’s iPhone provides a platform for freelance developers to design third party apps, which greatly expands the functionality and utility of mobile devices for stress management. This study provides a basic overview of the stress management apps under the health and fitness category of the Apple App store and appraises each app’s potential for influencing behavior change. Methods Data for this study came from a content analysis of health and fitness app descriptions available in the App Store on iTunes. Trained research assistants used the Precede-Proceed Model (PPM) as a framework to guide the coding of paid stress management apps and to evaluate each app’s potential for effecting health behavior change. Results Most apps were rated as being plausible (96.9%) and intending to address stress management (98.5%), but only 63.3% were rated as recommendable to others for their use. Reinforcing apps were less common than predisposing and enabling apps. Less than one percent (0.39%) of apps included all three factors (predisposing, enabling and reinforcing). Conclusions Practitioners should be cautious when promoting the use of stress management apps, as most provide only health-related information (predisposing) or suggestions for enabling behavior, but almost none include all three theoretical factors recommended for behavior change. PMID:28293583

Assessment of Factors Influencing Communication in Clinical Pharmacy.

PubMed

Yao, Dongning; Jiang, Liang; Huang, Yuankai; Chen, Lei; Wang, Yitao; Xi, Xiaoyu

2018-01-01

This study aimed to identify and assess the factors that influence communication quality between clinical pharmacists and patients using a structural equation model based on the predisposing, reinforcing, and enabling constructs in educational/environmental diagnosis and evaluation-policy, regulatory, and organizational constructs in educational and ecological development model to identify the most effective path to increase their communication quality. A survey was conducted at 253 Class-A tertiary hospitals in China from March to December 2016. During on-site observations, verbal communications between clinical pharmacists ( n = 752) and patients were audio recorded, and communication quality was rated by an expert panel on an 8-item Quality of Communication Rating Scale. Clinical pharmacists completed questionnaires that examined the predisposing, enabling, and reinforcing factors that influenced communication quality. Finally, AMOS was employed to examine the relationships between the three factors and communication quality. The results indicated that all three factors positively affected communication quality, with correlation coefficients of .26, .13, and .17, respectively. The most influential predisposing factor was attitude (.77), the most influential enabling factors were self-efficacy (.71) and confidence (.72), and the most influential reinforcing factor was rewards (.74). The findings suggest that pharmacists' attitudes toward, perceived knowledge of, and skill and confidence in communication, and the rewards offered by pharmacy management are the most influential factors that influence communication quality.

Immune predispositions for cytomegalovirus retinitis in AIDS. The HNRC Group.

PubMed Central

Schrier, R D; Freeman, W R; Wiley, C A; McCutchan, J A

1995-01-01

CMV retinitis develops in approximately 28-35% of all AIDS patients at later stages of disease, often leading to blindness. To determine whether the subset of AIDS patients who developed CMV retinitis (CMV-R) were immunologically predisposed, T cell proliferation responses to CMV were examined prospectively in an HIV infected, HLA typed, longitudinal study population. Individuals who developed CMV-R had significantly lower T cell proliferation responses to CMV, both early and late in disease, compared to CD4 matched controls who have not developed CMV-R. Since HLA proteins influence T-cell recognition, phenotypes of 21 CMV-R patients were examined to determine whether certain HLA alleles were associated with low immune response and predisposed AIDS patients to CMV-R. HLA DR7 and B44 were at increased (nearly twice the expected) frequency in those with CMV-R. The combined association of either B44, 51 or DR7 with CMV-R was highly significant (P = .008, relative risk of CMV-R = 15) with correction for multiple comparisons. Low immune responses were twice as frequent in those with (61%) compared to those without (30%) predisposing alleles. Thus, AIDS patients with immunogenetically related hyporesponsiveness to CMV antigens may be at increased risk of retinitis. PMID:7706482

Healthcare Utilization by Older Age Groups in Northern States of Peninsular Malaysia: The Role of Predisposing, Enabling and Need Factors.

PubMed

Samsudin, Shamzaeffa; Abdullah, Norehan

2017-06-01

Determining factors that affect healthcare utilization by the elderly is vital for the health system to be more responsive in providing care to this vulnerable group. The main objective of this paper is to identify the effect of the predisposing, enabling, and need factors on doctor visits and in-patient care for the elderly residing in the northern region of Malaysia. A multistage cluster sampling was used in selecting the sample for the study. A total of 1414 respondents aged 60 and over were interviewed face-to-face using a structured questionnaire. A probit model was used in estimating the utilization equations. At a significance level of 0.05, except for age, all predisposing and enabling factors were not statistically significant in affecting the doctor visits. On the other hand, being a male, smoker, medical insurance holder or had not actively involved in social interaction within the reference period increases the likelihood of being in-patient. Health-related variables remain the most significant factors that determine healthcare utilization, including both doctor visits and in-patient stays, in the area of study, which suggests that government policies to improve population health may influence the level of healthcare use in the future.

Trematode infections in pregnant ewes can predispose to mastitis during the subsequent lactation period.

PubMed

Mavrogianni, V S; Papadopoulos, E; Spanos, S A; Mitsoura, A; Ptochos, S; Gougoulis, D A; Barbagianni, M S; Kyriazakis, I; Fthenakis, G C

2014-02-01

Objective was to investigate if trematode infections predispose ewes to mastitis and/or metritis. We used 80 trematode-infected ewes: primigravidae in group P-A and multigravidae in M-A remained untreated, primigravidae in P-B and multigravidae in M-B were drenched with netobimin and multigravidae in M-C were given rafoxanide. We collected faecal samples for parasitological examination, blood samples for β-hydroxybutyrate concentration measurement and uterine content, teat duct material and milk samples for bacteriological examination. We found significant differences in blood β-hydroxybutyrate concentrations between M-A, M-B and M-C during pregnancy (P ⩽ 0.002). We did not observe significant differences between groups regarding development of metritis (P>0.83). We found that for M-A, M-B and M-C ewes, respectively, median time to first case of mastitis was 5.75, 21 and 6.75 days after lambing (P = 0.003) and incidence risk of mastitis was 0.308, 0.069 and 0.222 (P = 0.047). We postulate that trematode infections predispose ewes to mastitis; perhaps, increased β-hydroxybutyrate blood concentrations adversely affect mammary cellular defences. This is the first report associating parasitic infections with mastitis in sheep. Copyright © 2013 Elsevier Ltd. All rights reserved.

Gaps in patient care practices to prevent hospital-acquired delirium.

PubMed

Alagiakrishnan, Kannayiram; Marrie, Thomas; Rolfson, Darryl; Coke, William; Camicioli, Richard; Duggan, D'Arcy; Launhardt, Bonnie; Fisher, Bruce; Gordon, Debbie; Hervas-Malo, Marilou; Magee, Bernice; Wiens, Cheryl

2009-10-01

To evaluate the current patient care practices that address the predisposing and precipitating factors contributing to the prevention of hospital-acquired delirium in the elderly. Prospective cohort (observational) study. Patients 65 years of age and older who were admitted to medical teaching units at the University of Alberta Hospital in Edmonton over a period of 7 months and who were at risk of delirium. Medical teaching units at the University of Alberta. Demographic data and information on predisposing factors for hospital-acquired delirium were obtained for all patients. Documented clinical practices that likely prevent common precipitants of delirium were also recorded. Of the 132 patients enrolled, 20 (15.2%) developed hospital-acquired delirium. At the time of admission several predisposing factors were not documented (eg, possible cognitive impairment 16 [12%], visual impairment 52 [39.4%], and functional status of activities of daily living 99 [75.0%]). Recorded precipitating factors included catheter use, screening for dehydration, and medications. Catheters were used in 35 (26.5%) patients, and fluid intake-and-output charting assessed dehydration in 57 (43.2%) patients. At the time of admission there was no documentation of hearing status in 69 (52.3%) patients and aspiration risk in 104 (78.8%) patients. After admission, reorientation measures were documented in only 16 (12.1%) patients. Although all patients had brief mental status evaluations performed once daily, this was not noted to occur twice daily (which would provide important information about fluctuation of mental status) and there was no formal attention span testing. In this study, hospital-acquired delirium was also associated with increased mortality (P < .004), increased length of stay (P < .007), and increased institutionalization (P < .027). Gaps were noted in patient care practices that might contribute to hospital-acquired delirium and also in measures to identify the development of delirium at an earlier stage. Effort should be made to educate health professionals to identify the predisposing and precipitating factors, and to screen for delirium. This might improve the prevention of delirium.

The Role of Forest Tent Caterpillar Defoliations and Partial Harvest in the Decline and Death of Sugar Maple

PubMed Central

Hartmann, Henrik; Messier, Christian

2008-01-01

Background and Aims Natural and anthropogenic disturbances can act as stresses on tree vigour. According to Manion's conceptual model of tree disease, the initial vigour of trees decreases as a result of predisposing factors that render these trees more vulnerable to severe inciting stresses, stresses that can then cause final vigour decline and subsequent tree death. This tree disease model was tested in sugar maple (Acer saccharum) by assessing the roles of natural and anthropogenic disturbances in tree decline and death. Methods Radial growth data from 377 sugar maple trees that had undergone both defoliations by insects and partial harvest were used to estimate longitudinal survival probabilities as a proxy for tree vigour. Radial growth rates and survival probabilities were compared among trees subjected to different levels of above- and below-ground disturbances, between periods of defoliation and harvest, and between live and dead trees. Key Results Manion's tree disease model correctly accounts for vigour decline and tree death in sugar maple; tree growth and vigour were negatively affected by a first defoliation, predisposing these trees to death later during the study period due to a second insect outbreak that initiated a final vigour decline. This decline was accelerated by the partial harvest disturbance in 1993. Even the most severe anthropogenic disturbances from partial harvest did not cause, unlike insect defoliation, any growth or vigour declines in live sugar maple. Conclusions Natural disturbances acted as predisposing and inciting stresses in tree sugar maple decline and death. Anthropogenic disturbances from a partial harvest at worst accelerated a decline in trees that were already weakened by predisposing and inciting stresses (i.e. repeated insect defoliations). Favourable climatic conditions just before and after the partial harvest may have alleviated possible negative effects on growth resulting from harvesting. PMID:18660493

Is valve choice a significant determinant of paravalular leak post-transcatheter aortic valve implantation? A systematic review and meta-analysis.

PubMed

O'Sullivan, Katie E; Gough, Aideen; Segurado, Ricardo; Barry, Mitchel; Sugrue, Declan; Hurley, John

2014-05-01

Paravalvular regurgitation (PVR) following transcatheter aortic valve implantation (TAVI) is associated with poor survival. The two main valve delivery systems used to date differ significantly in both structure and deployment technique. The primary objective of this study was to perform a systematic review and meta-analysis of studies identifying PVR in patients post-TAVI using Medtronic CoreValve (MCV) and Edward Sapien (ES) valves in order to identify whether a significant difference exists between valve types. The secondary objective was to identify additional factors predisposing to PVR to provide an overview of the other associated considerations. A systematic review and meta-analysis of the current literature to identify PVR rate in patients with MCV and ES valves was performed. We also sought to examine other factors predisposing to PVR. A total of 5910 patients were identified from 9 studies. PVR rates for MCV and ES were analysed. MCV was associated with a higher PVR rate of 15.75% [95% confidence interval (CI) 12.48-19.32] compared with ES 3.93% [95% CI 1.05-8.38]. We separately reviewed predisposing factors associated with PVR. A formal comparison of the MCV and ES valve leakage rates by mixed-effects meta-regression with a fixed-effect moderator variable for valve type (MCV or ES) suggested a statistically significant difference in leakage rate between the two valve types (P = 0.0002). Unfavourable anatomical and pathological factors as well as valve choice have an impact on rates of PVR. Additionally, certain anatomical features dictate valve choice. A direct comparison of all the predisposing factors at this time is not possible and will require prospective multivariate analysis. There is, however, a significant difference in the PVR rates between valves based on the published observational data available to date. The ES valve associated with a lower incidence of PVR overall; therefore, we conclude that valve choice is indeed a significant determinant of PVR post-TAVI.

Femoral medullary infarction secondary to canine total hip arthroplasty.

PubMed

Sebestyen, P; Marcellin-Little, D J; DeYoung, B A

2000-01-01

To evaluate the prevalence of femoral intramedullary infarction after total hip arthroplasty (THA) and to determine whether any specific femoral morphology predisposes to bone infarction. Retrospective clinical study. All dogs from our hospital population undergoing THA between 1984 and 1997 with radiographic follow-up available at 1 year or more postoperatively. A case control study was conducted within the THA group to determine risk factors predisposing to femoral infarction after THA. Medical records and radiographs were reviewed. Data were collected on clinical parameters, femoral morphology, prosthesis, and bone changes. Radiographic diagnosis was confirmed using histopathology in 11 femora. Radiographs of 50 age-matched control dogs weighing more than 20 kg with coxofemoral degenerative joint disease were randomly chosen to determine the prevalence of bone infarction in nonoperated dogs. Ninety-one dogs with 110 THA were included in the study. Fifteen of the 110 femora with THA had radiographic evidence of infarction (14%). Infarction was not present in any femora in the control group. There was no significant difference in the prevalence of infarction between dogs that received cemented or uncemented prostheses. Clinical signs were not reported in any patient that developed femoral infarction. Young age (P = .03) and a distance between the greater trochanter and nutrient foramen greater than 79 mm (P = .008) predisposed dogs to femoral infarction. Over time, three infarcts decreased in size radiographically, five remained unchanged, and three expanded. An osteosarcoma developed at the site of a bone infarct in one dog. Femoral intramedullary infarction occurred in 15 of 110 THA. Young age at the time of THA and a greater distance between the greater trochanter and the nutrient foramen predisposed to infarction. Intramedullary infarction occurs after canine THA. These bone infarcts do not appear to cause clinical signs; however, they may present a diagnostic challenge. Malignant transformation could potentially result from medullary infarction.

Pglyrp-Regulated Gut Microflora Prevotella falsenii, Parabacteroides distasonis and Bacteroides eggerthii Enhance and Alistipes finegoldii Attenuates Colitis in Mice

PubMed Central

Dziarski, Roman; Dowd, Scot E.; Gupta, Dipika

2016-01-01

Dysbiosis is a hallmark of inflammatory bowel disease (IBD), but it is unclear which specific intestinal bacteria predispose to and which protect from IBD and how they are regulated. Peptidoglycan recognition proteins (Pglyrps) are antibacterial, participate in maintaining intestinal microflora, and modulate inflammatory responses. Mice deficient in any one of the four Pglyrp genes are more sensitive to dextran sulfate sodium (DSS)-induced colitis, and stools from Pglyrp-deficient mice transferred to wild type (WT) germ-free mice predispose them to much more severe colitis than stools from WT mice. However, the identities of these Pglyrp-regulated bacteria that predispose Pglyrp-deficient mice to colitis or protect WT mice from colitis are not known. Here we identified significant changes in β-diversity of stool bacteria in Pglyrp-deficient mice compared with WT mice. The most consistent changes in microbiome in all Pglyrp-deficient mice were in Bacteroidales, from which we selected four species, two with increased abundance (Prevotella falsenii and Parabacteroides distasonis) and two with decreased abundance (Bacteroides eggerthii and Alistipes finegoldii). We then gavaged WT mice with stock type strains of these species to test the hypothesis that they predispose to or protect from DSS-induced colitis. P. falsenii, P. distasonis, and B. eggerthii all enhanced DSS-induced colitis in both WT mice with otherwise undisturbed intestinal microflora and in WT mice with antibiotic-depleted intestinal microflora. By contrast, A. finegoldii (which is the most abundant species in WT mice) attenuated DSS-induced colitis both in WT mice with otherwise undisturbed intestinal microflora and in WT mice with antibiotic-depleted intestinal microflora, similar to the colitis protective effect of the entire normal microflora. These results identify P. falsenii, P. distasonis, and B. eggerthii as colitis-promoting species and A. finegoldii as colitis-protective species. PMID:26727498

The role of BRCA1 in homologous recombination repair in response to replication stress: significance in tumorigenesis and cancer therapy

PubMed Central

2013-01-01

Germ line mutations in breast cancer gene 1 (BRCA1) predispose women to breast and ovarian cancers. Although BRCA1 is involved in many important biological processes, the function of BRCA1 in homologous recombination (HR) mediated repair is considered one of the major mechanisms contributing to its tumor suppression activity, and the cause of hypersensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors when BRCA1 is defective. Mounting evidence suggests that the mechanism of repairing DNA double strand breaks (DSBs) by HR is different than the mechanism operating when DNA replication is blocked. Although BRCA1 has been recognized as a central component in HR, the precise role of BRCA1 in HR, particularly under replication stress, has remained largely unknown. Given the fact that DNA lesions caused by replication blockages are the primary substrates for HR in mitotic cells, functional analysis of BRCA1 in HR repair in the context of replication stress should benefit our understanding of the molecular mechanisms underlying tumorigenesis associated with BRCA1 deficiencies, as well as the development of therapeutic approaches for cancer patients carrying BRCA1 mutations or reduced BRCA1 expression. This review focuses on the current advances in this setting and also discusses the significance in tumorigenesis and cancer therapy. PMID:23388117

Role of Sirt1 during the ageing process: relevance to protection of synapses in the brain.

PubMed

Godoy, Juan A; Zolezzi, Juan M; Braidy, Nady; Inestrosa, Nibaldo C

2014-12-01

Ageing is a stochastic process associated with a progressive decline in physiological functions which predispose to the pathogenesis of several neurodegenerative diseases. The intrinsic complexity of ageing remains a significant challenge to understand the cause of this natural phenomenon. At the molecular level, ageing is thought to be characterized by the accumulation of chronic oxidative damage to lipids, proteins and nucleic acids caused by free radicals. Increased oxidative stress and misfolded protein formations, combined with impaired compensatory mechanisms, may promote neurodegenerative disorders with age. Nutritional modulation through calorie restriction has been shown to be effective as an anti-ageing factor, promoting longevity and protecting against neurodegenerative pathology in yeast, nematodes and murine models. Calorie restriction increases the intracellular levels of the essential pyridine nucleotide, nicotinamide adenine dinucleotide (NAD(+)), a co-substrate for the sirtuin 1 (Sirt1, silent mating-type information regulator 2 homolog 1) activity and a cofactor for oxidative phosphorylation and ATP synthesis. Promotion of intracellular NAD(+) anabolism is speculated to induce neuroprotective effects against amyloid-β-peptide (Aβ) toxicity in some models for Alzheimer's disease (AD). The NAD(+)-dependent histone deacetylase, Sirt1, has been implicated in the ageing process. Sirt1 serves as a deacetylase for numerous proteins involved in several cellular pathways, including stress response and apoptosis, and plays a protective role in neurodegenerative disorders, such as AD.

Antiarrhythmic properties of atrial pacing.

PubMed

Kliś, Magdalena; Sławuta, Agnieszka; Gajek, Jacek

2017-01-01

Bradycardia, atrial stretch and dilatation, autonomic nervous system disorders, and the presence of triggers such as atrial premature contractions, are factors which predispose a person to paroxysmal AF. Atrial pacing not only eliminates bradycardia but also prevents atrial premature contractions and dispersion of refractoriness, which are a substrate for atrial fibrillation. As the prolonged duration of atrial activation during pacing, especially from locations changing the physiological pattern of this activation (right atrium lateral wall, right atrium appendage), negatively influences both a mechanical and an electrical function of the atria, the atrial pacing site affects an atrial arrhythmogenesis. A conventional atrial lead location in the right atrium appendage causes non-physiological activation propagation, resulting in a prolongation of the activation time of both atria. This location is optimal according to a passive fixation of the atrial lead but the available contemporary active fixation leads could potentially be located in any area of the atrium. There is growing evidence of the benefit of pacing, imitating the physiological propagation of impulses within the atria. It seems that the Bachmann's bundle pacing is the best pacing site within the atria, not only positively influencing the atrial mechanical function but also best fulfilling the so-called atrial resynchronization function, in particular in patients with interatrial conduction delay. It can be effectively achieved using only one atrial electrode, and the slight shortening of atrioventricular conduction provides an additional benefit of this atrial pacing site.

Post-operative atrial fibrillation: a maze of mechanisms

PubMed Central

Maesen, Bart; Nijs, Jan; Maessen, Jos; Allessie, Maurits; Schotten, Ulrich

2012-01-01

Post-operative atrial fibrillation (POAF) is one of the most frequent complications of cardiac surgery and an important predictor of patient morbidity as well as of prolonged hospitalization. It significantly increases costs for hospitalization. Insights into the pathophysiological factors causing POAF have been provided by both experimental and clinical investigations and show that POAF is ‘multi-factorial’. Facilitating factors in the mechanism of the arrhythmia can be classified as acute factors caused by the surgical intervention and chronic factors related to structural heart disease and ageing of the heart. Furthermore, some proarrhythmic mechanisms specifically occur in the setting of POAF. For example, inflammation and beta-adrenergic activation have been shown to play a prominent role in POAF, while these mechanisms are less important in non-surgical AF. More recently, it has been shown that atrial fibrosis and the presence of an electrophysiological substrate capable of maintaining AF also promote the arrhythmia, indicating that POAF has some proarrhythmic mechanisms in common with other forms of AF. The clinical setting of POAF offers numerous opportunities to study its mechanisms. During cardiac surgery, biopsies can be taken and detailed electrophysiological measurements can be performed. Furthermore, the specific time course of POAF, with the delayed onset and the transient character of the arrhythmia, also provides important insight into its mechanisms. This review discusses the mechanistic interaction between predisposing factors and the electrophysiological mechanisms resulting in POAF and their therapeutic implications. PMID:21821851

The Aurora kinase inhibitor CCT137690 downregulates MYCN and sensitizes MYCN-amplified neuroblastoma in vivo

PubMed Central

Faisal, Amir; Vaughan, Lynsey; Bavetsias, Vassilios; Sun, Chongbo; Atrash, Butrus; Avery, Sian; Jamin, Yann; Robinson, Simon P.; Workman, Paul; Blagg, Julian; Raynaud, Florence I.; Eccles, Suzanne A.; Chesler, Louis; Linardopoulos, Spiros

2015-01-01

The Aurora kinases regulate key stages of mitosis including centrosome maturation, spindle assembly, chromosome segregation and cytokinesis. Aurora A and B overexpression has also been associated with various human cancers and as such, they have been extensively studied as novel anti-mitotic drug targets. Here we characterise the Aurora kinase inhibitor CCT137690, a highly selective, orally bioavailable imidazo[4,5-b]pyridine derivative that inhibits Aurora A and B kinases with low nanomolar IC50 values in both biochemical and cellular assays and exhibits anti-proliferative activity against a wide range of human solid tumour cell lines. CCT137690 efficiently inhibits histone H3 and TACC3 phosphorylation (Aurora B and Aurora A substrates, respectively) in HCT116 and HeLa cells. Continuous exposure of tumour cells to the inhibitor causes multipolar spindle formation, chromosome misalignment, polyploidy and apoptosis. This is accompanied by p53/p21/BAX induction, thymidine kinase 1 (TK1) downregulation and PARP cleavage. Furthermore, CCT137690 treatment of MYCN-amplified neuroblastoma cell lines inhibits cell proliferation and decreases MYCN protein expression. Importantly, in a transgenic mouse model of neuroblastoma (TH-MYCN) that overexpresses MYCN protein and is predisposed to spontaneous neuroblastoma formation, this compound significantly inhibits tumour growth. The potent preclinical activity of CCT137690 suggests that this inhibitor may benefit patients with MYCN amplified neuroblastoma. PMID:21885865

Motivational Processes Underlying Substance Abuse Disorder

PubMed Central

King, Christopher P.; Ferrario, Carrie R.

2016-01-01

Drug addiction is a syndrome of dysregulated motivation, evidenced by intense drug craving and compulsive drug-seeking behavior. In the search for common neurobiological substrates of addiction to different classes of drugs, behavioral neuroscientists have attempted to determine the neural basis for a number of motivational concepts and describe how they are changed by repeated drug use. Here, we describe these concepts and summarize previous work describing three major neural systems that play distinct roles in different conceptual aspects of motivation: (1) a nigrostriatal system that is involved in two forms of instrumental learning, (2) a ventral striatal system that is involved in Pavlovian incentive motivation and negative reinforcement, and (3) frontal cortical areas that regulate decision making and motivational processes. Within striatal systems, drug addiction can involve a transition from goal-oriented, incentive processes to automatic, habit-based responding. In the cortex, weak inhibitory control is a predisposing factor to, as well as a consequence of, repeated drug intake. However, these transitions are not absolute, and addiction can occur without a transition to habit-based responding, occurring as a result of the overvaluation of drug outcomes and hypersensitivity to incentive properties of drug-associated cues. Finally, we point out that addiction is not monolithic and can depend not only on individual differences between addicts, but also on the neurochemical action of specific drug classes. PMID:26475159

Evaluation of brine disposal from the Bryan Mound site of the Strategic Petroleum Reserve Program. Final report

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

Hann, R.W. Jr.; Randall, R.E.

1980-12-01

The purpose of this report is to describe the environmental conditions found by the principal investigators during the predisposal study conducted from September 1977 through February 1980 prior to the start of brine discharge in March 1980. The major areas of investigation are physical oceanography, analysis of the discharge plume, water and sediment quality, nekton, benthos, phytoplankton, zooplankton, and data management. Volume 1 describes the results of the predisposal study, and it is divided into eight chapters entitled: Physical Oceanography, Analsyis of the Discharge Plume, Water and Sediment Quality, Nekton, Benthos, Zooplankton, Phytoplankton, and Data Management. Volume 2 consists ofmore » appendices which contain additional supporting data in the form of figures and tables.« less

Impact of Survivorship-Based Research on Defining Clinical Care Guidelines

PubMed Central

Hudson, Melissa M.; Landier, Wendy; Ganz, Patricia A.

2011-01-01

The growing number of individuals living 5 or more years from cancer diagnosis underscores the importance of providing guidance about potential late treatment effects to clinicians caring for long-term cancer survivors. Late treatment effects are commonly experienced by cancer survivors, increase in prevalence with aging, produce substantial morbidity, and predispose to early mortality. Findings from survivorship research permit providers to anticipate health risks among predisposed survivors and facilitate their access to interventions to prevent, detect, or rehabilitate cancer-related morbidity. This manuscript reviews the impact that survivorship research has made in defining clinical care guidelines and the challenges that remain in developing and translating research findings into health screening recommendations that can optimize the quality and duration of survival after cancer. PMID:21980016

Seizures in an Alzheimer's disease patient as a complication of colonoscopy premedication with meperidine.

PubMed

Nagler, Jerry; Hammarth, Patricia M; Poppers, David M

2008-01-01

We describe the first reported case of generalized tonic-clonic seizures induced by meperidine premedication for a colonoscopy procedure in a 63-year-old woman with Alzheimer's disease. The active metabolite of meperidine, normeperidine, is postulated to be the precipitating cause of the seizures, although a cholinesterase inhibitor and an N-methyl-D: -aspartate receptor antagonist, both routinely used for treatment of Alzheimer's disease, may have contributed by reducing the seizure threshold. The neuronal changes which occur in Alzheimer's disease can themselves also predispose to seizures. We recommend avoidance of meperidine for all flexible endoscopic procedures on patients with Alzheimer's disease and in any patient with a condition that predisposes to seizures, and suggest the use of alternative opioids.

Evaluation of brine disposal from the Bryan Mound site of the Strategic Petroleum Reserve Program. Final report

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

Hann, R.W. Jr.; Randall, R.E.

1980-12-01

The purpose of this report is to describe the environmental conditions found by the principal investigators during the predisposal study conducted from September 1977 through February 1980 prior to the start of brine discharge in March 1980. The major areas of investigation are physical oceanography, analysis of the discharge plume, water and sediment quality, nekton, benthos, phytoplankton, zooplankton, and data management. Volume 1 describes the results of the predisposal study, and it is divided into eight chapters entitled: Physical Oceanography, Analysis of the Discharge Plume, Water and Sediment Quality, Nekton, Benthos, Zooplankton, Phytoplankton, and Data Management. Volume 2 consists ofmore » appendices which contain additional supporting data in the form of figures and tables.« less

[Vascular trombosis of renal graft: 9 cases].

PubMed

Kaaroud, Hayet; Béji, Soumaya; Ben Hamida, Fethi; Rais, Lamia; Ben Abdallah, Taieb; El Younsi, Fethi; Ben Moussa, Fatma; Abderrahim, Ezzedine; Bardi, Rafika; Ayed, Khaled; Chebil, Mohamed; Kheder, Adel

2008-04-01

Allograft renal thrombosis can occur in 1 to 6% of cases. Many predisposing factors has been identified especially alteration of coagulation. We analyzed in this study frequency and predisposing factors of renal graft thrombosis. We report a retrospective study including 319 renal transplant recipients. Nine patients (2.8%) presented veinous graft thrombosis in 5 cases and arterial thombosis in 4 cases. There were 6 men and 3 women aged of 30.6 years meanly (10-56) which developed the thrombosis 6 days (1-48) after the transplantation. All patients were detransplanted after 16.2 days and 1 patient died. Thrombosis constitute an important cause of graft loss. A perfect surgical technic and prophylactic treatment in high risk patients are necessary to reduce this complication.

Recent Arctic tundra fire initiates widespread thermokarst development.

PubMed

Jones, Benjamin M; Grosse, Guido; Arp, Christopher D; Miller, Eric; Liu, Lin; Hayes, Daniel J; Larsen, Christopher F

2015-10-29

Fire-induced permafrost degradation is well documented in boreal forests, but the role of fires in initiating thermokarst development in Arctic tundra is less well understood. Here we show that Arctic tundra fires may induce widespread thaw subsidence of permafrost terrain in the first seven years following the disturbance. Quantitative analysis of airborne LiDAR data acquired two and seven years post-fire, detected permafrost thaw subsidence across 34% of the burned tundra area studied, compared to less than 1% in similar undisturbed, ice-rich tundra terrain units. The variability in thermokarst development appears to be influenced by the interaction of tundra fire burn severity and near-surface, ground-ice content. Subsidence was greatest in severely burned, ice-rich upland terrain (yedoma), accounting for ~50% of the detected subsidence, despite representing only 30% of the fire disturbed study area. Microtopography increased by 340% in this terrain unit as a result of ice wedge degradation. Increases in the frequency, magnitude, and severity of tundra fires will contribute to future thermokarst development and associated landscape change in Arctic tundra regions.

Large-scale fabrication of micro-lens array by novel end-fly-cutting-servo diamond machining.

PubMed

Zhu, Zhiwei; To, Suet; Zhang, Shaojian

2015-08-10

Fast/slow tool servo (FTS/STS) diamond turning is a very promising technique for the generation of micro-lens array (MLA). However, it is still a challenge to process MLA in large scale due to certain inherent limitations of this technique. In the present study, a novel ultra-precision diamond cutting method, as the end-fly-cutting-servo (EFCS) system, is adopted and investigated for large-scale generation of MLA. After a detailed discussion of the characteristic advantages for processing MLA, the optimal toolpath generation strategy for the EFCS is developed with consideration of the geometry and installation pose of the diamond tool. A typical aspheric MLA over a large area is experimentally fabricated, and the resulting form accuracy, surface micro-topography and machining efficiency are critically investigated. The result indicates that the MLA with homogeneous quality over the whole area is obtained. Besides, high machining efficiency, extremely small volume of control points for the toolpath, and optimal usage of system dynamics of the machine tool during the whole cutting can be simultaneously achieved.

Tundra landform and vegetation productivity trend maps for the Arctic Coastal Plain of northern Alaska

NASA Astrophysics Data System (ADS)

Lara, Mark J.; Nitze, Ingmar; Grosse, Guido; McGuire, A. David

2018-04-01

Arctic tundra landscapes are composed of a complex mosaic of patterned ground features, varying in soil moisture, vegetation composition, and surface hydrology over small spatial scales (10-100 m). The importance of microtopography and associated geomorphic landforms in influencing ecosystem structure and function is well founded, however, spatial data products describing local to regional scale distribution of patterned ground or polygonal tundra geomorphology are largely unavailable. Thus, our understanding of local impacts on regional scale processes (e.g., carbon dynamics) may be limited. We produced two key spatiotemporal datasets spanning the Arctic Coastal Plain of northern Alaska (~60,000 km2) to evaluate climate-geomorphological controls on arctic tundra productivity change, using (1) a novel 30 m classification of polygonal tundra geomorphology and (2) decadal-trends in surface greenness using the Landsat archive (1999-2014). These datasets can be easily integrated and adapted in an array of local to regional applications such as (1) upscaling plot-level measurements (e.g., carbon/energy fluxes), (2) mapping of soils, vegetation, or permafrost, and/or (3) initializing ecosystem biogeochemistry, hydrology, and/or habitat modeling.

An Investigation of the Hypotheses for Formation of the Platy-Ridged Terrain in Elysium Planitia, Mars

NASA Astrophysics Data System (ADS)

Yue, Z.; Gou, S.; Michael, G.; Di, K.; Xie, H.; Gong, H.; Shao, Y.

2017-07-01

The origin of the platy-ridged-polygonized (PRP) terrains on Martian surface has long been debated. The terrain has generally been classified as water, pack ice, or basalt lava related flow. The crater counting results of the PRP terrains suggest they are geologically very young; therefore, they are significant in understanding the recent evolution of Mars. This work evaluated the current hypotheses through detailed analysis of the distribution and microtopographies with the High Resolution Imaging Science Experiment (HiRISE) images for the PRP terrains in Elysium Planitia, Mars. Quantitative measurements and statistics of the typical features of the PRP terrains were also made. In addition, we also found an analog site in Tarim Basin in Xinjiang, China. Our results suggest that mud flow is responsible for the formation of the PRP terrains on the Mars surface, although the hypothesis of low-viscosity basalt lava floods cannot be completely excluded. This finding implies that a regional environment suitable for liquid water may have existed in recent geologic time, which has great importance for future Mars scientific exploration.

Recent Arctic tundra fire initiates widespread thermokarst development

PubMed Central

Jones, Benjamin M.; Grosse, Guido; Arp, Christopher D.; Miller, Eric; Liu, Lin; Hayes, Daniel J.; Larsen, Christopher F.

2015-01-01

Fire-induced permafrost degradation is well documented in boreal forests, but the role of fires in initiating thermokarst development in Arctic tundra is less well understood. Here we show that Arctic tundra fires may induce widespread thaw subsidence of permafrost terrain in the first seven years following the disturbance. Quantitative analysis of airborne LiDAR data acquired two and seven years post-fire, detected permafrost thaw subsidence across 34% of the burned tundra area studied, compared to less than 1% in similar undisturbed, ice-rich tundra terrain units. The variability in thermokarst development appears to be influenced by the interaction of tundra fire burn severity and near-surface, ground-ice content. Subsidence was greatest in severely burned, ice-rich upland terrain (yedoma), accounting for ~50% of the detected subsidence, despite representing only 30% of the fire disturbed study area. Microtopography increased by 340% in this terrain unit as a result of ice wedge degradation. Increases in the frequency, magnitude, and severity of tundra fires will contribute to future thermokarst development and associated landscape change in Arctic tundra regions. PMID:26511650

Tundra landform and vegetation productivity trend maps for the Arctic Coastal Plain of northern Alaska.

PubMed

Lara, Mark J; Nitze, Ingmar; Grosse, Guido; McGuire, A David

2018-04-10

Arctic tundra landscapes are composed of a complex mosaic of patterned ground features, varying in soil moisture, vegetation composition, and surface hydrology over small spatial scales (10-100 m). The importance of microtopography and associated geomorphic landforms in influencing ecosystem structure and function is well founded, however, spatial data products describing local to regional scale distribution of patterned ground or polygonal tundra geomorphology are largely unavailable. Thus, our understanding of local impacts on regional scale processes (e.g., carbon dynamics) may be limited. We produced two key spatiotemporal datasets spanning the Arctic Coastal Plain of northern Alaska (~60,000 km 2 ) to evaluate climate-geomorphological controls on arctic tundra productivity change, using (1) a novel 30 m classification of polygonal tundra geomorphology and (2) decadal-trends in surface greenness using the Landsat archive (1999-2014). These datasets can be easily integrated and adapted in an array of local to regional applications such as (1) upscaling plot-level measurements (e.g., carbon/energy fluxes), (2) mapping of soils, vegetation, or permafrost, and/or (3) initializing ecosystem biogeochemistry, hydrology, and/or habitat modeling.

Distance and environmental difference in alpine plant communities

USGS Publications Warehouse

Malanson, George P.; Zimmerman, Dale L.; Fagre, Daniel B.

2017-01-01

Differences in plant communities are a response to the abiotic environment, species interactions, and dispersal. The role of geographic distance relative to the abiotic environment is explored for alpine tundra vegetation from 319 plots of four regions along the Rocky Mountain cordillera in the USA. The site by species data were ordinated using nonmetric multidimensional scaling to produce dependent variables for use in best-subsets regression. For independent variables, observations of local topography and microtopography were used as environmental indicators. Two methods of including distance in studies of vegetation and environment are used and contrasted. The relative importance of geographic distance in accounting for the pattern of alpine tundra similarity indicates that location is a factor in plant community composition. Mantel tests provide direct correlations between difference and distance but have known weaknesses. Moran spatial eigenvectors used in regression based approaches have greater geographic specificity, but require another step, ordination, in creating a vegetation variable. While the spatial eigenvectors are generally preferable, where species–environment relations are weak, as seems to be the case for the alpine sites studied here, the fewer abstractions of the Mantel test may be useful.

The Evolution of Silica Nanoparticle-polyester Coatings on Surfaces Exposed to Sunlight.

PubMed

Truong, Vi Khanh; Stefanovic, Miljan; Maclaughlin, Shane; Tobin, Mark; Vongsvivut, Jitraporn; Al Kobaisi, Mohammad; Crawford, Russell J; Ivanova, Elena P

2016-10-11

Corrosion of metallic surfaces is prevalent in the environment and is of great concern in many areas, including the military, transport, aviation, building and food industries, amongst others. Polyester and coatings containing both polyester and silica nanoparticles (SiO2NPs) have been widely used to protect steel substrata from corrosion. In this study, we utilized X-ray photoelectron spectroscopy, attenuated total reflection infrared micro-spectroscopy, water contact angle measurements, optical profiling and atomic force microscopy to provide an insight into how exposure to sunlight can cause changes in the micro- and nanoscale integrity of the coatings. No significant change in surface micro-topography was detected using optical profilometry, however, statistically significant nanoscale changes to the surface were detected using atomic force microscopy. Analysis of the X-ray photoelectron spectroscopy and attenuated total reflection infrared micro-spectroscopy data revealed that degradation of the ester groups had occurred through exposure to ultraviolet light to form COO·, -H2C·, -O·, -CO· radicals. During the degradation process, CO and CO2 were also produced.

Recent Arctic tundra fire initiates widespread thermokarst development

DOE PAGES

Jones, Benjamin M.; Grosse, Guido; Arp, Christopher D.; ...

2015-10-29

Fire-induced permafrost degradation is well documented in boreal forests, but the role of fires in initiating thermokarst development in Arctic tundra is less well understood. Here we show that Arctic tundra fires may induce widespread thaw subsidence of permafrost terrain in the first seven years following the disturbance. Quantitative analysis of airborne LiDAR data acquired two and seven years post-fire, detected permafrost thaw subsidence across 34% of the burned tundra area studied, compared to less than 1% in similar undisturbed, ice-rich tundra terrain units. The variability in thermokarst development appears to be influenced by the interaction of tundra fire burnmore » severity and near-surface, ground-ice content. Subsidence was greatest in severely burned, ice-rich upland terrain (yedoma), accounting for -50% of the detected subsidence, despite representing only 30% of the fire disturbed study area. Microtopography increased by 340% in this terrain unit as a result of ice wedge degradation. Increases in the frequency, magnitude, and severity of tundra fires will contribute to future thermokarst development and associated landscape change in Arctic tundra regions.« less

Measurement of surface water runoff from plots of two different sizes

NASA Astrophysics Data System (ADS)

Joel, Abraham; Messing, Ingmar; Seguel, Oscar; Casanova, Manuel

2002-05-01

Intensities and amounts of water infiltration and runoff on sloping land are governed by the rainfall pattern and soil hydraulic conductivity, as well as by the microtopography and soil surface conditions. These components are closely interrelated and occur simultaneously, and their particular contribution may change during a rainfall event, or their effects may vary at different field scales. The scale effect on the process of infiltration/runoff was studied under natural field and rainfall conditions for two plot sizes: small plots of 0·25 m2 and large plots of 50 m2. The measurements were carried out in the central region of Chile in a piedmont most recently used as natural pastureland. Three blocks, each having one large plot and five small plots, were established. Cumulative rainfall and runoff quantities were sampled every 5 min. Significant variations in runoff responses to rainfall rates were found for the two plot sizes. On average, large plots yielded only 40% of runoff quantities produced on small plots per unit area. This difference between plot sizes was observed even during periods of continuous runoff.

Effect of metal surface topography on mechanical bonding at simulated total hip stem-cement interfaces.

PubMed

Chen, C Q; Scott, W; Barker, T M

1999-01-01

Bonding and loosening mechanisms between bone cement and joint prostheses have not been well identified. In this study, the effects of simulated hip stem surface topography on the interfacial shear strength were examined. Six different surface topographies were used. They were described by several surface characterization parameters that may directly relate to the interfacial bonding strength: average surface roughness R(a), root mean square slope R(Deltaq), correlation length beta, and fluid retention index R(ri). The shear strengths between Palacos E bone cement and stainless steel rods were measured using an Instron materials testing machine. We found that cement can "flow" into the surface microtopography and establish good contact with the metal surface. The results show that the interfacial strength increases monotonically with the increase of R(Deltaq) instead of with R(a). The relationship between interfacial strength and surface parameters shows that a metal stem with an isotropic surface texture, higher R(Deltaq), and greater R(ri) gives a higher interfacial strength. Copyright 1999 John Wiley & Sons, Inc.

Recent Arctic tundra fire initiates widespread thermokarst development

USGS Publications Warehouse

Jones, Benjamin M.; Grosse, Guido; Arp, Christopher D.; Miller, Eric K.; Liu, Lingli; Hayes, Daniel J.; Larsen, Christopher F.

2015-01-01

Fire-induced permafrost degradation is well documented in boreal forests, but the role of fires in initiating thermokarst development in Arctic tundra is less well understood. Here we show that Arctic tundra fires may induce widespread thaw subsidence of permafrost terrain in the first seven years following the disturbance. Quantitative analysis of airborne LiDAR data acquired two and seven years post-fire, detected permafrost thaw subsidence across 34% of the burned tundra area studied, compared to less than 1% in similar undisturbed, ice-rich tundra terrain units. The variability in thermokarst development appears to be influenced by the interaction of tundra fire burn severity and near-surface, ground-ice content. Subsidence was greatest in severely burned, ice-rich upland terrain (yedoma), accounting for ~50% of the detected subsidence, despite representing only 30% of the fire disturbed study area. Microtopography increased by 340% in this terrain unit as a result of ice wedge degradation. Increases in the frequency, magnitude, and severity of tundra fires will contribute to future thermokarst development and associated landscape change in Arctic tundra regions.

Micro-topographic hydrologic variability due to vegetation acclimation under climate change

NASA Astrophysics Data System (ADS)

Le, P. V.; Kumar, P.

2012-12-01

Land surface micro-topography and vegetation cover have fundamental effects on the land-atmosphere interactions. The altered temperature and precipitation variability associated with climate change will affect the water and energy processes both directly and that mediated through vegetation. Since climate change induces vegetation acclimation that leads to shifts in evapotranspiration and heat fluxes, it further modifies microclimate and near-surface hydrological processes. In this study, we investigate the impacts of vegetation acclimation to climate change on micro-topographic hydrologic variability. The ability to accurately predict these impacts requires the simultaneous considerations of biochemical, ecophysiological and hydrological processes. A multilayer canopy-root-soil system model coupled with a conjunctive surface-subsurface flow model is used to capture the acclimatory responses and analyze the changes in dynamics of structure and connectivity of micro-topographic storage and in magnitudes of runoff. The study is performed using Light Detection and Ranging (LiDAR) topographic data in the Birds Point-New Madrid floodway in Missouri, U.S.A. The result indicates that both climate change and its associated vegetation acclimation play critical roles in altering the micro-topographic hydrological responses.

Urinary Tract Infection among Renal Transplant Recipients in Yemen

PubMed Central

Gondos, Adnan S.; Al-Moyed, Khaled A.; Al-Robasi, Abdul Baki A.; Al-Shamahy, Hassan A.; Alyousefi, Naelah A.

2015-01-01

Urinary tract infection (UTI) is the most common complication following kidney transplantation (KT), which could result in losing the graft. This study aims to identify the prevalence of bacterial UTI among KT recipients in Yemen and to determine the predisposing factors associated with post renal transplantation UTI. A cross sectional study included of 150 patients, who underwent KT was conducted between June 2010 and January 2011. A Morning mid-stream urine specimen was collected for culture and antibiotic susceptibility test from each recipient. Bacterial UTI was found in 50 patients (33.3%). The prevalence among females 40.3% was higher than males 29%. The UTI was higher in the age group between 41–50 years with a percentage of 28% and this result was statistically significant. Predisposing factors as diabetes mellitus, vesicoureteral reflux, neurogenic bladder and polycystic kidney showed significant association. High relative risks were found for polycystic kidney = 13.5 and neurogenic bladder = 13.5. The most prevalent bacteria to cause UTI was Escherichia coli represent 44%, followed by Staphylococcus saprophyticus 34%. Amikacin was the most effective antibiotic against gram-negative isolates while Ciprofloxacin was the most effective antibiotic against Staphylococcus saprophyticus. In conclusion, there is high prevalence of bacterial UTI among KT recipients in Yemen. Diabetes mellitus, vesicoureteral reflux, neurogenic bladder, polycystic kidney and calculi were the main predisposing factors. PMID:26657128

Promoting physical activity in the workplace: A systematic meta-review

PubMed Central

Jirathananuwat, Areeya; Pongpirul, Krit

2017-01-01

Introduction: Physically active (PA) people have a lower risk of various diseases, compared to those with sedentary lifestyles. Evidence on the effects of PA promoting programs in the workplace is large, and several systematic reviews (SR) and/or meta-analyses (MA) have been published. However, they have failed to consider factors that could influence interventions. This paper aimed to classify and describe interventions to promote PA in the workplace based on evidence from SR/MA. Method: A literature search for SR/MA was done using PubMed, Web of Science, and Science Direct (January 2006-February 2015). Quality assessment of SR/MA was performed using AMSTAR. The PRECEDE-PROCEED model was used for classifying the interventions into predisposing, enabling, reinforcing, environment, and policy domains of focus. Results: Eleven SR/MA included 220 primary studies, of which 139 (63%) were randomized controlled trials. Of 48 interventions identified, 22 (46%) and 17 (35%) focused on predisposing or enabling employees to have more PA, respectively. Of the 22 predisposing factors, 6 were information delivery, 5 were self-motivation, and 11 were program training. The enabling approaches were 12 instrument resources and 5 health service facilities. The reinforcing approaches were 4 incentive and 3 social support. The remaining interventions focused on the environmental development and policy regulation. Conclusions: This systematic meta-review classified interventions using appropriate framework and described the intervention pattern. PMID:28740029

Promoting physical activity in the workplace: A systematic meta-review.

PubMed

Jirathananuwat, Areeya; Pongpirul, Krit

2017-09-28

Physically active (PA) people have a lower risk of various diseases, compared to those with sedentary lifestyles. Evidence on the effects of PA promoting programs in the workplace is large, and several systematic reviews (SR) and/or meta-analyses (MA) have been published. However, they have failed to consider factors that could influence interventions. This paper aimed to classify and describe interventions to promote PA in the workplace based on evidence from SR/MA. A literature search for SR/MA was done using PubMed, Web of Science, and Science Direct (January 2006-February 2015). Quality assessment of SR/MA was performed using AMSTAR. The PRECEDE-PROCEED model was used for classifying the interventions into predisposing, enabling, reinforcing, environment, and policy domains of focus. Eleven SR/MA included 220 primary studies, of which 139 (63%) were randomized controlled trials. Of 48 interventions identified, 22 (46%) and 17 (35%) focused on predisposing or enabling employees to have more PA, respectively. Of the 22 predisposing factors, 6 were information delivery, 5 were self-motivation, and 11 were program training. The enabling approaches were 12 instrument resources and 5 health service facilities. The reinforcing approaches were 4 incentive and 3 social support. The remaining interventions focused on the environmental development and policy regulation. This systematic meta-review classified interventions using appropriate framework and described the intervention pattern.

Cigarette Smoke Attenuates the Nasal Host Response to Streptococcus pneumoniae and Predisposes to Invasive Pneumococcal Disease in Mice

PubMed Central

Shen, Pamela; Morissette, Mathieu C.; Vanderstocken, Gilles; Gao, Yang; Hassan, Muhammad; Roos, Abraham; Thayaparan, Danya; Merlano, Maria; Dorrington, Michael G.; Nikota, Jake K.; Bauer, Carla M. T.; Kwiecien, Jacek M.; Labiris, Renee; Bowdish, Dawn M. E.; Stevenson, Christopher S.

2016-01-01

Streptococcus pneumoniae is a leading cause of invasive bacterial infections, with nasal colonization an important first step in disease. While cigarette smoking is a strong risk factor for invasive pneumococcal disease, the underlying mechanisms remain unknown. This is partly due to a lack of clinically relevant animal models investigating nasal pneumococcal colonization in the context of cigarette smoke exposure. We present a model of nasal pneumococcal colonization in cigarette smoke-exposed mice and document, for the first time, that cigarette smoke predisposes to invasive pneumococcal infection and mortality in an animal model. Cigarette smoke increased the risk of bacteremia and meningitis without prior lung infection. Mechanistically, deficiency in interleukin 1α (IL-1α) or platelet-activating factor receptor (PAFR), an important host receptor thought to bind and facilitate pneumococcal invasiveness, did not rescue cigarette smoke-exposed mice from invasive pneumococcal disease. Importantly, we observed cigarette smoke to attenuate nasal inflammatory mediator expression, particularly that of neutrophil-recruiting chemokines, normally elicited by pneumococcal colonization. Smoking cessation during nasal pneumococcal colonization rescued nasal neutrophil recruitment and prevented invasive disease in mice. We propose that cigarette smoke predisposes to invasive pneumococcal disease by suppressing inflammatory processes of the upper respiratory tract. Given that smoking prevalence remains high worldwide, these findings are relevant to the continued efforts to reduce the invasive pneumococcal disease burden. PMID:26930709

“Viral déjà vu” elicits organ-specific immune disease independent of reactivity to self

PubMed Central

Merkler, Doron; Horvath, Edit; Bruck, Wolfgang; Zinkernagel, Rolf M.; del la Torre, Juan Carlos; Pinschewer, Daniel D.

2006-01-01

Autoimmune diseases are often precipitated by viral infections. Yet our current understanding fails to explain how viruses trigger organ-specific autoimmunity despite thymic tolerance extending to many nonlymphohematopoietic self antigens. Additionally, a key epidemiological finding needs to be explained: In genetically susceptible individuals, early childhood infections seem to predispose them to multiple sclerosis (MS) or type 1 diabetes years or even decades before clinical onset. In the present work, we show that the innate immune system of neonatal mice was sufficient to eliminate an attenuated lymphocytic choriomeningitis virus (LCMV) from most tissues except for the CNS, where the virus persisted in neurons (predisposing virus). Virus-specific cytotoxic T cells (CTLs) were neither deleted nor sufficiently primed to cause disease, but they were efficiently triggered in adulthood upon WT LCMV infection (precipitating virus). This defined sequence of viral infections caused severe CNS inflammation that was histomorphologically reminiscent of rasmussen encephalitis, a fatal human autoimmune disease. Yet disease in mice was mediated by antiviral CTLs targeting an epitope shared by the precipitating virus and the predisposing virus persisting in neurons (déjà vu). Thus the concept of “viral déjà vu” demonstrates how 2 related but independently encountered viral infections can cause organ-specific immune disease without molecular mimicry of self and without breaking self tolerance. PMID:16604192

Predictors of healthcare utilization among older Mexican Americans.

PubMed

Al Snih, Soham; Markides, Kyriakos S; Ray, Laura A; Freeman, Jean L; Ostir, Glenn V; Goodwin, James S

2006-01-01

To examine the effects of predisposing, enabling, and need factors on physician and hospital use among older Mexican Americans. A two-year prospective cohort study. Five Southwestern states: Texas, New Mexico, Colorado, Arizona, and California. A population-based sample of 1987 non-institutionalized Mexican American men and women age > or =65 years. Physician and hospital utilization. Predictor variables included predisposing, enabling, and need factors. Ordinary least square and logistic regression analysis were used to model the effects of predictor factors specified in the Andersen model of health service use on physician and hospital use. After two years of follow-up, predisposing and enabling factors accounted for <5% of the variance in physician and hospital use. Need factors explained 21% of the variance in physician use and 7% of the variance in hospital use. Older age; being female; insurance coverage; having arthritis, diabetes, heart attack, hypertension, stroke, or cancer; and number of medications were factors associated with higher physician utilization. Subjects with arthritis, diabetes, hip fracture, high depressive symptoms, activities of daily living (ADL) disability, or high number of medications increased the odds of having any hospitalization. Subjects with diabetes, heart attack, hip fracture, ADL disabled, and high number of medications had a greater number of hospital nights than their counterparts. Older age, female sex, insurance coverage, and prevalent medical conditions are determinants of healthcare use among older Mexican Americans.

Bacterial keratitis: predisposing factors, clinical and microbiological review of 300 cases

PubMed Central

Bourcier, T; Thomas, F; Borderie, V; Chaumeil, C; Laroche, L

2003-01-01

Aim: To identify predisposing factors and to define clinical and microbiological characteristics of bacterial keratitis in current practice. Methods: A retrospective analysis of the hospital records of patients presenting with bacterial keratitis and treated at the Quinze-Vingts National Center of Ophthalmology, Paris, France, was performed during a 20 month period. A bacterial keratitis was defined as a suppurative corneal infiltrate and overlying epithelial defect associated with presence of bacteria on corneal scraping and/or that was cured with antibiotic therapy. Risk factors, clinical and microbiological data were collected. Results: 300 cases (291 patients) of presumed bacterial keratitis were included. Potential predisposing factors, usually multiple, were identified in 90.6% of cases. Contact lens wear was the main risk factor (50.3%). Trauma or a history of keratopathy was found in 15% and 21% of cases, respectively. An organism was identified in 201 eyes (68%). 83% of the infections involved Gram positive bacteria, 17% involved Gram negative bacteria, and 2% were polymicrobial. Gram negative bacteria were associated with severe anterior chamber inflammation (p=0.004), as well as greater surface of infiltrates (p=0.01). 99% of ulcers resolved with treatment, but only 60% of patients had visual acuity better than the level at admission, and 5% had very poor visual outcome. Conclusions: Contact lens wear is the most important risk factor. Most community acquired bacterial ulcers resolve with appropriate treatment. PMID:12812878

Incidence and predisposing factors of common upper respiratory tract infections in vocal students during their professional training.

PubMed

Zimmer-Nowicka, Joanna; Januszewska-Stańczyk, Henryka

2011-07-01

Upper respiratory tract infections (URTI) are among the major causes of dysphonia. There are only scarce data available on the incidence and predisposing factors of URTI in young singers, in particular, during a period of intense voice training. The data were obtained from medical records and a 43-item questionnaire distributed among 94 students of the vocal faculty (66 females and 28 males-age: 23.5±3.7 years) at all levels of their studies. The questions were divided into several categories, that is, personal, anthropometric, demographic, history of vocal education, and both general and singer-specific health risk factors. The rate of URTI showed a steady decrease during vocal studies. The strongest factor predisposing to infections in the multivariate regression model was nonadherence to vocal hygiene. There was also a weak protective effect of a regular holiday rest and negative effect of allergy. The prevalence of several recognized risk factors of URTI was exceptionally high in the group of vocal students, for example, passive smoking (42.5%), poor dental status (39.4%), frequent gastric complaints (44.7%), and allergy (50%). Despite the persistence of many risk factors throughout the vocal studies, the frequency of URTI significantly decreases most likely because of vocal hygiene education and growing professional experience. Copyright © 2011 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Drought predisposes piñon-juniper woodlands to insect attacks and mortality.

PubMed

Gaylord, Monica L; Kolb, Thomas E; Pockman, William T; Plaut, Jennifer A; Yepez, Enrico A; Macalady, Alison K; Pangle, Robert E; McDowell, Nate G

2013-04-01

To test the hypothesis that drought predisposes trees to insect attacks, we quantified the effects of water availability on insect attacks, tree resistance mechanisms, and mortality of mature piñon pine (Pinus edulis) and one-seed juniper (Juniperus monosperma) using an experimental drought study in New Mexico, USA. The study had four replicated treatments (40 × 40 m plot/replicate): removal of 45% of ambient annual precipitation (H2 O-); irrigation to produce 125% of ambient annual precipitation (H2 O+); a drought control (C) to quantify the impact of the drought infrastructure; and ambient precipitation (A). Piñon began dying 1 yr after drought initiation, with higher mortality in the H2 O- treatment relative to other treatments. Beetles (bark/twig) were present in 92% of dead trees. Resin duct density and area were more strongly affected by treatments and more strongly associated with piñon mortality than direct measurements of resin flow. For juniper, treatments had no effect on insect resistance or attacks, but needle browning was highest in the H2 O- treatment. Our results provide strong evidence that ≥ 1 yr of severe drought predisposes piñon to insect attacks and increases mortality, whereas 3 yr of the same drought causes partial canopy loss in juniper. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Proton magnetic resonance spectroscopy shows lower intramyocellular lipid accumulation in middle-aged subjects predisposed to familial longevity.

PubMed

Wijsman, C A; van Opstal, A M; Kan, H E; Maier, A B; Westendorp, R G J; Slagboom, P E; Webb, A G; Mooijaart, S P; van Heemst, D

2012-02-01

Families predisposed to longevity show enhanced glucose tolerance and skeletal muscle insulin sensitivity compared with controls, independent of body composition and physical activity. Intramyocellular lipid (IMCL) accumulation in skeletal muscle has been associated with insulin resistance. Here, we assessed whether subjects enriched for familial longevity have lower IMCL levels. We determined IMCL levels in 48 subjects from the Leiden Longevity Study, comprising 24 offspring of nonagenarian siblings and 24 partners thereof as control subjects. IMCL levels were assessed noninvasively using short echo time proton magnetic resonance spectroscopy ((1)H-MRS) of the tibialis anterior muscle with a 7 Tesla human MR scanner. IMCL levels were calculated relative to the total creatine (tCr) CH3 signal. Physical activity was assessed using the International Physical Activity Questionnaire (IPAQ). After correction for age, sex, BMI, and physical activity, offspring of long-lived nonagenarian siblings tended to show lower IMCL levels compared with controls (IMCL/tCr: 3.1 ± 0.5 vs. 4.5 ± 0.5, respectively, P = 0.051). In a pairwise comparison, this difference reached statistical significance (P = 0.038). We conclude that offspring of nonagenarian siblings predisposed to longevity show lower IMCL levels compared with environmentally matched control subjects. Future research should focus on assessing what mechanisms may explain the lower IMCL levels in familial longevity.

Neurosarcoidosis

MedlinePlus

... and fund research into the disease mechanisms of sarcoidosis, predisposing factors, genetic underpinnings, and the potential for ... better ways to diagnose, treat, and ultimately cure sarcoidosis and neurosarcardoisis. Information from the National Library of ...

Assessing the impact of antidrug advertising on adolescent drug consumption: results from a behavioral economic model.

PubMed

Block, Lauren G; Morwitz, Vicki G; Putsis, William P; Sen, Subrata K

2002-08-01

This study examined whether adolescents' recall of antidrug advertising is associated with a decreased probability of using illicit drugs and, given drug use, a reduced volume of use. A behavioral economic model of influences on drug consumption was developed with survey data from a nationally representative sample of adolescents to determine the incremental impact of antidrug advertising. The findings provided evidence that recall of antidrug advertising was associated with a lower probability of marijuana and cocaine/crack use. Recall of such advertising was not associated with the decision of how much marijuana or cocaine/crack to use. Results suggest that individuals predisposed to try marijuana are also predisposed to try cocaine/crack. The present results provide support for the effectiveness of antidrug advertising programs.

Primary immunodeficiencies predisposed to Epstein-Barr virus-driven haematological diseases.

PubMed

Parvaneh, Nima; Filipovich, Alexandra H; Borkhardt, Arndt

2013-09-01

Epstein-Barr virus (EBV), a ubiquitous human herpesvirus, maintains lifelong subclinical persistent infections in humans. In the circulation, EBV primarily infects the B cells, and protective immunity is mediated by EBV-specific cytotoxic T cells (CTLs) and natural killer (NK) cells. However, EBV has been linked to several devastating diseases, such as haemophagocytic lymphohistiocytosis (HLH) and lymphoproliferative diseases in the immunocompromised host. Some types of primary immunodeficiencies (PIDs) are characterized by the development of EBV-associated complications as their predominant clinical feature. The study of such genetic diseases presents an ideal opportunity for a better understanding of the biology of the immune responses against EBV. Here, we summarize the range of PIDs that are predisposed to EBV-associated haematological diseases, describing their clinical picture and pathogenetic mechanisms. © 2013 John Wiley & Sons Ltd.

Sex differences in the effects of androgens acting in the central nervous system on metabolism

PubMed Central

Morford, Jamie; Mauvais-Jarvis, Franck

2016-01-01

One of the most sexually dimorphic aspects of metabolic regulation is the bidirectional modulation of glucose and energy homeostasis by testosterone in males and females. Testosterone deficiency predisposes men to metabolic dysfunction, with excess adiposity, insulin resistance, and type 2 diabetes, whereas androgen excess predisposes women to insulin resistance, adiposity, and type 2 diabetes. This review discusses how testosterone acts in the central nervous system, and especially the hypothalamus, to promote metabolic homeostasis or dysfunction in a sexually dimorphic manner. We compare the organizational actions of testosterone, which program the hypothalamic control of metabolic homeostasis during development, and the activational actions of testosterone, which affect metabolic function after puberty. We also discuss how the metabolic effect of testosterone is centrally mediated via the androgen receptor. PMID:28179813

Recurrent posttraumatic meningitis due to nontypable Haemophilus influenzae: case report and review of the literature.

PubMed

Kunze, W; Müller, L; Kilian, M; Schuhmann, M U; Baumann, L; Handrick, W

2008-02-01

We report a case of relapsing Haemophilus influenzae meningitis in a boy at the age of nearly 3 years and 4.2 years who had been successfully vaccinated against H. influenzae serotype b (Hib). The pathogen was a nonencapsulated (nontypable) H. influenzae strain of biotypes III and VI, respectively. A rhinobasal impalement injury with development of a posttraumatic encephalocele is considered to be the predisposing condition. Review of the literature reveals that in patients systemically infected by nonencapsulated H. influenzae strains predisposing factors such as cerebrospinal fluid-shunts, implants and traumas are often found. To obtain further information on potential new disease patterns H. influenzae isolates from cerebrospinal fluid should be examined for capsule production and, if relevant, further characterized by capsular typing.

Human natural killer cells prevent infectious mononucleosis features by targeting lytic Epstein-Barr virus infection

PubMed Central

Chijioke, Obinna; Müller, Anne; Feederle, Regina; Barros, Mario Henrique M.; Krieg, Carsten; Emmel, Vanessa; Marcenaro, Emanuela; Leung, Carol S.; Antsiferova, Olga; Landtwing, Vanessa; Bossart, Walter; Moretta, Alessandro; Hassan, Rocio; Boyman, Onur; Niedobitek, Gerald; Delecluse, Henri-Jacques; Capaul, Riccarda; Münz, Christian

2014-01-01

SUMMARY Primary infection with the human oncogenic Epstein Barr virus (EBV) can result in infectious mononucleosis (IM), a self-limiting disease caused by massive lymphocyte expansion, which predisposes for the development of distinct EBV-associated lymphomas. It remains unclear why some individuals experience this symptomatic primary EBV infection, while the majority acquires the virus asymptomatically. Using a mouse model with reconstituted human immune system components, we show here that depletion of human natural killer (NK) cells enhances IM symptoms and promotes EBV-associated tumorigenesis, mainly due to loss of immune control over lytic EBV infection. These data suggest that failure of innate immune control by human NK cells augments symptomatic lytic EBV infection, which drives lymphocyte expansion and predisposes for EBV-associated malignancies. PMID:24360958

Coexisting ankylosing spondylitis and rheumatoid arthritis: a case report with literature review.

PubMed

Guo, Ying-Ying; Yang, Li-Li; Cui, Hua-Dong; Zhao, Shuai; Zhang, Ning

2011-10-01

A 30-year-old female patient with coexisting ankylosing spondylitis and rheumatoid arthritis was diagnosed and treated. The human leukocyte antigen (HLA)-B27 is a predisposing factor of ankylosing spondylitis and HLA-DR4 is a predisposing factor of rheumatoid arthritis. This patient was HLA-B27 and HLA-DR4 positive, and ankylosing spondylitis manifested before rheumatoid arthritis. After disease modifying anti-rheumatic drugs successfully arrested ankylosing spondylitis activity the patient conceived and delivered a healthy baby. One year later, she developed peripheral polyarthritis and was diagnosed with rheumatoid arthritis. We hypothesized that pregnancy may be one of the environmental factors that can activate rheumatoid arthritis, and that disease modifying anti-rheumatic drugs play an important role in keeping the disease under control.

Extra-hepatic hepatocellular carcinoma presenting as obstructive jaundice.

PubMed

Batsis, J A; Halfdanarson, T R; Pitot, H

2006-10-01

Hepatocellular carcinoma is a neoplasm with a uniformly poor prognosis. Risk factors for its development include chronic hepatitis B or C infection, haemochromatosis and alpha-1-antitrypsin deficiency, but individuals with any type of chronic liver disease are predisposed. The incidence is significantly higher in Asia and Africa although it has been noted to be increasing in the United States. We present a patient with notable atypical clinical features for hepatocellular carcinoma. The patient had neither predisposing risk factors nor a primary liver lesion causing obstructive jaundice. After multiple tissue specimens were obtained, the final pathological diagnosis was established. Hepatocellular carcinoma generally requires a surgical cure, but patients who are icteric often portend poorer prognoses. For those at high risk, screening may be indicated to identify early curative treatment.

Restoring Psychology's Role in Peptic Ulcer

PubMed Central

Overmier, J Bruce; Murison, Robert

2013-01-01

This paper reviews the history of the transition from the belief that gastrointestinal ulcers are caused primarily by psychological factors to the current state of belief that they are caused primarily by infection and argues that neither is fully accurate. We argue that psychological factors play a significant role as predisposing to vulnerability, modulating of precipitation, and sustaining of gastric ulceration. We review data that challenge the assumption of a simple infectious disease model and adduce recent preclinical data that confirm the predisposing, modulatory, and sustaining roles for psychological factors. We note that others, too, are now challenging the adequacy of the contemporary simple bacterial infection model. We hope to replace the competition between psychology and medicine with cooperation in understanding and treating patients suffering gastric ulceration and ulcer. PMID:23457084

32 CFR 644.391 - Predisposal conference.

Code of Federal Regulations, 2010 CFR

2010-07-01

... economy of the local community. For this purpose, installations, in many cases, will be reported to GSA... will be developed in conjunction with appropriate using command and GSA representatives. Its purpose...

Modelling effects of tree population dynamics, tree throw and pit-mound formation/diffusion on microtopography over time in different forest settings

NASA Astrophysics Data System (ADS)

Martin, Y. E.; Johnson, E. A.; Gallaway, J.; Chaikina, O.

2011-12-01

Herein we conduct a followup investigation to an earlier research project in which we developed a numerical model of tree population dynamics, tree throw, and sediment transport associated with the formation of pit-mound features for Hawk Creek watershed, Canadian Rockies (Gallaway et al., 2009). We extend this earlier work by exploring the most appropriate transport relations to simulate the diffusion over time of newly-formed pit-pound features due to tree throw. We combine our earlier model with a landscape development model that can incorporate these diffusive transport relations. Using these combined models, changes in hillslope microtopography over time associated with the formation of pit-mound features and their decay will be investigated. The following ideas have motivated this particular study: (i) Rates of pit-mound degradation remain a source of almost complete speculation, as there is almost no long-term information on process rates. Therefore, we will attempt to tackle the issue of pit-mound degradation in a methodical way that can guide future field studies; (ii) The degree of visible pit-mound topography at any point in time on the landscape is a joint function of the rate of formation of new pit-mound features due to tree death/topple and their magnitude vs. the rate of decay of pit-mound features. An example of one interesting observation that arises is the following: it appears that pit-mound topography is often more pronounced in some eastern North American forests vs. field sites along the eastern slopes of the Canadian Rockies. Why is this the case? Our investigation begins by considering whether pit-mound decay might occur by linear or nonlinear diffusion. What differences might arise depending on which diffusive approach is adopted? What is the magnitude of transport rates associated with these possible forms of transport relations? We explore linear and nonlinear diffusion at varying rates and for different sizes of pit-mound pairs using a numerical modelling approach. Model results suggest that longevity of pit-mound features is dependent on: (i) magnitude/dimensions of initial pit-mound features for forests in different regions; (ii) defining appropriate pit-mound diffusion rates for these different forests (unfortunately, almost no appropriate field observations exist for calibration of these transport relations). In the next stage of this research, we will combine our earlier model of forest disturbance/tree population dynamics, tree throw and pit-mound formation with the numerical model LandMod (Martin, 1998, 2000, 2007); the latter will be used to simulate pit-mound diffusion over time. In this way, we can observe changes in hillslope microtopographic signatures over time that are found in different forest settings.

Surface-structural Control on Minor Element Zoning and Growth Mechanism in Synthetic Magmatic Clinopyroxene

NASA Astrophysics Data System (ADS)

Paquette, J.; Deakin, M.; Baker, D. R.

2006-12-01

Because in situ observations of actively growing surfaces are technically impractical, our understanding of crystal growth mechanisms at hydrothermal and magmatic conditions lags behind that of minerals that can be grown from aqueous solutions at or near room temperature. Growing silicate minerals from hydrous synthetic carbonate melts offers the opportunity to relate directly minor element incorporation to their surface microtopography. Natural hydrothermal diopside was used to seed experiments in which synthetic clinopyroxene crystals were grown at 800 degrees C and 10 kbars for 24 hours, from alkaline melts modelled after the lavas of the Tanzanian volcano Oldoinyo Lengai. The melts were prepared from Na2CO3, K2CO3, CaCO3, MgCO3 and Fe3O4 reagents. One run was anhydrous and the others contained either 2.5 or 5 wt. % H2O. Euhedral tabular crystals ranging in size from 100 to 300 ìm across were found in all three runs, hand-picked and freed from their carbonate matrix by overnight immersion in dilute acetic acid. The crystals consist of \\{110\\} prism, \\{100\\} and \\{001\\} pinacoids and a \\{111\\} dipyramid. AFM images resolved a distinct surface microtopography on each form: arrays of broad macrosteps on \\{100\\}, lens- shaped islands on \\{001\\} facets and striated fiber-like crystallites on \\{110\\}. EMP analyses of polished grain mounts show that compositional zoning of Na and Fe occurs not only among non-equivalent growth sectors but also within single \\{100\\} sectors. Electron microprobe maps of sequentially polished sections indicate that zoning within \\{100\\} sectors reflects differential uptake of Na and Fe on symmetrically non-equivalent steps. Near the crystal surface, the non- equivalent coeval vicinal faces of growth hillocks on \\{100\\} are either diopside-like, Na.007Ca1.00(Mg0.754Fe2+0.22Mn2+0.013Al_{0.003)Si2.00O6 , or acmitic, Ca0.63Na0.35(Mg0.64Fe3+ 0.36)Al0.01Si1.99O6 in composition. Step-specific incorporation of minor elements in a clinopyroxene face has only been documented once, in a hydrothermal diopside from Orford (Quebec), where Fe(II) and Mn(II) were differentially incorporated on steps oriented parallel to [010] on \\{100\\} faces. This natural example and our synthetic crystals reflect growth regimes where minor element incorporation was limited by surface-structural kinetics rather than diffusion- controlled kinetics. Such step-specific surface-structural control has never been reported in clinopyroxenes grown from silicate melts. Is it present, but more subtle, or do silicate melts promote a significantly different growth regime? Comparing zoning patterns in synthetic silicates grown from carbonate versus silicate melts could put new constraints on current models of element partitioning.

Gaps in patient care practices to prevent hospital-acquired delirium

PubMed Central

Alagiakrishnan, Kannayiram; Marrie, Thomas; Rolfson, Darryl; Coke, William; Camicioli, Richard; Duggan, D’Arcy; Launhardt, Bonnie; Fisher, Bruce; Gordon, Debbie; Hervas-Malo, Marilou; Magee, Bernice; Wiens, Cheryl

2009-01-01

ABSTRACT OBJECTIVE To evaluate the current patient care practices that address the predisposing and precipitating factors contributing to the prevention of hospital-acquired delirium in the elderly. DESIGN Prospective cohort (observational) study. PARTICIPANTS Patients 65 years of age and older who were admitted to medical teaching units at the University of Alberta Hospital in Edmonton over a period of 7 months and who were at risk of delirium. SETTING Medical teaching units at the University of Alberta. MAIN OUTCOME MEASURES Demographic data and information on predisposing factors for hospital-acquired delirium were obtained for all patients. Documented clinical practices that likely prevent common precipitants of delirium were also recorded. RESULTS Of the 132 patients enrolled, 20 (15.2%) developed hospital-acquired delirium. At the time of admission several predisposing factors were not documented (eg, possible cognitive impairment 16 [12%], visual impairment 52 [39.4%], and functional status of activities of daily living 99 [75.0%]). Recorded precipitating factors included catheter use, screening for dehydration, and medications. Catheters were used in 35 (26.5%) patients, and fluid intake-and-output charting assessed dehydration in 57 (43.2%) patients. At the time of admission there was no documentation of hearing status in 69 (52.3%) patients and aspiration risk in 104 (78.8%) patients. After admission, reorientation measures were documented in only 16 (12.1%) patients. Although all patients had brief mental status evaluations performed once daily, this was not noted to occur twice daily (which would provide important information about fluctuation of mental status) and there was no formal attention span testing. In this study, hospital-acquired delirium was also associated with increased mortality (P < .004), increased length of stay (P < .007), and increased institutionalization (P < .027). CONCLUSION Gaps were noted in patient care practices that might contribute to hospital-acquired delirium and also in measures to identify the development of delirium at an earlier stage. Effort should be made to educate health professionals to identify the predisposing and precipitating factors, and to screen for delirium. This might improve the prevention of delirium. PMID:19826141

PREVALENCE OF CELIAC DISEASE PREDISPOSING GENOTYPES, INCLUDING HLA-DQ2.2 VARIANT, IN BRAZILIAN CHILDREN.

PubMed

Selleski, Nicole; Almeida, Lucas Malta; Almeida, Fernanda Coutinho de; Pratesi, Claudia Beatriz; Nóbrega, Yanna Karla de Medeiros; Gandolfi, Lenora

2018-01-01

Celiac disease is an autoimmune enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. Almost all celiac patients carry immune recognition genes coding for HLA-DQ2.5 and DQ8 heterodimers. Over the last few years, great importance has been given to HLA-DQ2.2 as probable predisposing variant, although controversies still exist regarding its relevance. The aim of our study was to determine the possible existence of an association between HLA-DQ2.2 and celiac disease in Brazilian children by analyzing the prevalence of the predisposing variants for celiac disease in a representative group of children of a population in which this determination is still missing. HLA-DQ typing was performed in samples from a group of celiac (n=100) and non-celiac children (n=110). All samples were tested for the presence of the following variants: DQA1*05-DQB1*02 (DQ2.5), DQA1*03-DQB1*03:02 (DQ8) and DQA1*02:01-DQB1*02:02 (DQ2.2). Fisher`s exact test was used for statistical analysis. In the group of 100 celiac children, 78 (78%) were positive for DQ2, 13 (13 %) were DQ2/DQ8 and 6 (6%) were DQ8 positives. The HLA-DQ pattern in the 110 non-celiac children was as follows: positive for DQ2 in 33 (29.9%) samples, in 2 (1.8 %) was positive for DQ2/DQ8 and in 15 (13.6%) was positive for DQ8. We found significant differences between the distribution of some but not all of the analyzed alleles when comparing celiac and non-celiac children. The genotyping of celiac disease HLA-DQ predisposing alleles showed similarities with HLA-DQ patterns found in both European and non-European populations, which may be a reflection of the miscegenation, which gave origin to the current Brazilian population. No significant association was found between DQ2.2 variant and celiac disease in the studied population.

Genomic characterization of biliary tract cancers identifies driver genes and predisposing mutations.

PubMed

Wardell, Christopher P; Fujita, Masashi; Yamada, Toru; Simbolo, Michele; Fassan, Matteo; Karlic, Rosa; Polak, Paz; Kim, Jaegil; Hatanaka, Yutaka; Maejima, Kazuhiro; Lawlor, Rita T; Nakanishi, Yoshitsugu; Mitsuhashi, Tomoko; Fujimoto, Akihiro; Furuta, Mayuko; Ruzzenente, Andrea; Conci, Simone; Oosawa, Ayako; Sasaki-Oku, Aya; Nakano, Kaoru; Tanaka, Hiroko; Yamamoto, Yujiro; Michiaki, Kubo; Kawakami, Yoshiiku; Aikata, Hiroshi; Ueno, Masaki; Hayami, Shinya; Gotoh, Kunihito; Ariizumi, Shun-Ichi; Yamamoto, Masakazu; Yamaue, Hiroki; Chayama, Kazuaki; Miyano, Satoru; Getz, Gad; Scarpa, Aldo; Hirano, Satoshi; Nakamura, Toru; Nakagawa, Hidewaki

2018-05-01

Biliary tract cancers (BTCs) are clinically and pathologically heterogeneous and respond poorly to treatment. Genomic profiling can offer a clearer understanding of their carcinogenesis, classification and treatment strategy. We performed large-scale genome sequencing analyses on BTCs to investigate their somatic and germline driver events and characterize their genomic landscape. We analyzed 412 BTC samples from Japanese and Italian populations, 107 by whole-exome sequencing (WES), 39 by whole-genome sequencing (WGS), and a further 266 samples by targeted sequencing. The subtypes were 136 intrahepatic cholangiocarcinomas (ICCs), 101 distal cholangiocarcinomas (DCCs), 109 peri-hilar type cholangiocarcinomas (PHCs), and 66 gallbladder or cystic duct cancers (GBCs/CDCs). We identified somatic alterations and searched for driver genes in BTCs, finding pathogenic germline variants of cancer-predisposing genes. We predicted cell-of-origin for BTCs by combining somatic mutation patterns and epigenetic features. We identified 32 significantly and commonly mutated genes including TP53, KRAS, SMAD4, NF1, ARID1A, PBRM1, and ATR, some of which negatively affected patient prognosis. A novel deletion of MUC17 at 7q22.1 affected patient prognosis. Cell-of-origin predictions using WGS and epigenetic features suggest hepatocyte-origin of hepatitis-related ICCs. Deleterious germline mutations of cancer-predisposing genes such as BRCA1, BRCA2, RAD51D, MLH1, or MSH2 were detected in 11% (16/146) of BTC patients. BTCs have distinct genetic features including somatic events and germline predisposition. These findings could be useful to establish treatment and diagnostic strategies for BTCs based on genetic information. We here analyzed genomic features of 412 BTC samples from Japanese and Italian populations. A total of 32 significantly and commonly mutated genes were identified, some of which negatively affected patient prognosis, including a novel deletion of MUC17 at 7q22.1. Cell-of-origin predictions using WGS and epigenetic features suggest hepatocyte-origin of hepatitis-related ICCs. Deleterious germline mutations of cancer-predisposing genes were detected in 11% of patients with BTC. BTCs have distinct genetic features including somatic events and germline predisposition. Copyright © 2018 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Crash-type manual for pedestrians

DOT National Transportation Integrated Search

1996-01-01

Bicyclists or pedestrians are involved in approximately one out of six highway fatalities each year. This research was conducted in order to better understand the precipitating actions, predisposing factors and characteristic populations involved. So...

Runaway Children in America: A Review of the Literature.

ERIC Educational Resources Information Center

Burke, William H.; Burkhead, E. Jane

1989-01-01

The paper reviews the literature regarding runaway children, defines runaway youth, and discusses predisposing factors. Suggestions are offered for further research on the etiology and treatment of runaway behavior. (JDD)

Teenage Prostitution.

ERIC Educational Resources Information Center

Brown, Marjorie E.

1979-01-01

This paper explores: precipitating social conditions which might predispose an adolescent girl to deviant sexual activity; experiences which may initiate entrance into prostitution; and the treatment of sexual deviance in young girls by the Juvenile Justice System. (Author)

Accident proneness : a research review.

DOT National Transportation Integrated Search

1993-05-01

Accident proneness is a concept that refers to an enduring or stable personality characteristic that predisposes an individual toward having accidents (Haddon, Suchman, and Klein, 1964). The concept is controversial and has sustained a lively debate ...

32 CFR 644.391 - Predisposal conference.

Code of Federal Regulations, 2011 CFR

2011-07-01

... that the Report of Excess to GSA specifically identifies and excludes the real and personal property to... GSA will be summarized in the report, along with any other problems encountered or foreseen. (d) When...

Yeast Can Affect Behavior and Learning.

ERIC Educational Resources Information Center

Crook, William G.

1984-01-01

A pediatrician recounts his experiences in diagnosing and treating allergies to common yeast germs that may result in behavior and learning problems. He lists characteristics that may predispose children to yeast-connected health problems. (CL)

Mucocutaneous candidiasis in a mandrill (Mandrillus sphinx).

PubMed

Zöller, M; Silinski, S; Ludwig, C; Weig, M; Mätz-Rensing, K; Kaup, F-J

2012-01-01

An adult male mandrill (Mandrillus sphinx) suffered from chronic ulceration of the facial and gluteal skin and the oral and nasal mucosa. The ulcers were resistant to therapy and led to deterioration in the general condition of the animal. Microscopical examination revealed a severe, chronic, multifocal, granulomatous and eosinophilic dermatitis and panniculitis. There was also stomatitis and rhinitis with numerous intralesional fungal elements. These organisms were identified by immunohistochemistry, transmission electron microscopy, polymerase chain reaction and fungal culture as Candida albicans. Species identification was confirmed by MALDI-TOF mass spectrometry. A specific predisposing immunosuppressive factor for the deep chronic mucocutaneous candidiasis was not identified; however, social stress and/or a primary defect in cell-mediated immunity could not be excluded as possible causes for a predisposing immunodeficiency in the animal. Copyright © 2011 Elsevier Ltd. All rights reserved.

Tuberculosis of the ear, a professional disease?

PubMed

Sens, Patrícia Maria; Almeida, Clemente I R; Valle, Lupércio O do; Costa, Luís H C; Angeli, Miguel L S

2008-01-01

Tuberculosis is a rare cause of chronic suppurative otitis media and mastoiditis; the predisposing factors of this association, however, are not commonly described. There has been an alarming increase in the incidence of tuberculosis in Brazil, including tuberculous otitis media. These patients typically present multiple perforations of the tympanic membrane, an ear discharge, and progressive hearing loss. This diagnosis should be taken into account in patients that do not respond to routine therapy for fungal external otitis or bacterial otitis media. In this retrospective study, the authors describe four cases of patients with tuberculous otitis media. This sample consisted of two physicians, a chemical engineer and an underage child in whose family there were cases of active tuberculosis. Predisposing factors for tuberculous otitis were contact with family members that had tuberculosis, professional contact with patients and exposure to pathogenic microorganisms in airways.

Human natural killer cells prevent infectious mononucleosis features by targeting lytic Epstein-Barr virus infection.

PubMed

Chijioke, Obinna; Müller, Anne; Feederle, Regina; Barros, Mario Henrique M; Krieg, Carsten; Emmel, Vanessa; Marcenaro, Emanuela; Leung, Carol S; Antsiferova, Olga; Landtwing, Vanessa; Bossart, Walter; Moretta, Alessandro; Hassan, Rocio; Boyman, Onur; Niedobitek, Gerald; Delecluse, Henri-Jacques; Capaul, Riccarda; Münz, Christian

2013-12-26

Primary infection with the human oncogenic Epstein-Barr virus (EBV) can result in infectious mononucleosis (IM), a self-limiting disease caused by massive lymphocyte expansion that predisposes for the development of distinct EBV-associated lymphomas. Why some individuals experience this symptomatic primary EBV infection, whereas the majority acquires the virus asymptomatically, remains unclear. Using a mouse model with reconstituted human immune system components, we show that depletion of human natural killer (NK) cells enhances IM symptoms and promotes EBV-associated tumorigenesis mainly because of a loss of immune control over lytic EBV infection. These data suggest that failure of innate immune control by human NK cells augments symptomatic lytic EBV infection, which drives lymphocyte expansion and predisposes for EBV-associated malignancies. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Clinics in diagnostic imaging (163). Transient lateral patellar dislocation with trochlear dysplasia

PubMed Central

Zhang, Junwei; Lee, Chin Hwee

2015-01-01

A 14-year-old girl presented with left knee pain and swelling after an injury. Magnetic resonance (MR) imaging showed a transient lateral patellar dislocation with patellar osteochondral fracture, medial patellofemoral ligament tear and underlying femoral trochlear dysplasia. Open reduction and internal fixation of the osteochondral fracture, plication of the medial patellar retinaculum and lateral release were performed. As lateral patellar dislocation is often clinically unsuspected, an understanding of its characteristic imaging features is important in making the diagnosis. Knowledge of the various predisposing factors for patellar instability may also influence the choice of surgical management. We also discuss signs of acute injury and chronic instability observed on MR imaging, and the imaging features of anatomical variants that predispose an individual to lateral patellar dislocation. Treatment options and postsurgical imaging appearances are also briefly described. PMID:26512145

Gene-Environment Interactions Controlling Energy and Glucose Homeostasis and the Developmental Origins of Obesity

PubMed Central

Bouret, Sebastien; Levin, Barry E.; Ozanne, Susan E.

2015-01-01

Obesity and type 2 diabetes mellitus (T2DM) often occur together and affect a growing number of individuals in both the developed and developing worlds. Both are associated with a number of other serious illnesses that lead to increased rates of mortality. There is likely a polygenic mode of inheritance underlying both disorders, but it has become increasingly clear that the pre- and postnatal environments play critical roles in pushing predisposed individuals over the edge into a disease state. This review focuses on the many genetic and environmental variables that interact to cause predisposed individuals to become obese and diabetic. The brain and its interactions with the external and internal environment are a major focus given the prominent role these interactions play in the regulation of energy and glucose homeostasis in health and disease. PMID:25540138

Prematurity and low weight at birth as new conditions predisposing to an increased cardiovascular risk.

PubMed

Mercuro, Giuseppe; Bassareo, Pier Paolo; Flore, Giovanna; Fanos, Vassilios; Dentamaro, Ilaria; Scicchitano, Pietro; Laforgia, Nicola; Ciccone, Marco Matteo

2013-04-01

Although the survival rate for preterm subjects has improved considerably, due to the progress in the field of perinatal medicine, preterm birth is frequently the cause underlying a series of notorious complications: morphological, neurological, ophthalmological, and renal alterations. In addition, it has recently been demonstrated how low gestational age and reduced foetal growth contribute towards an increased cardiovascular risk in preterm neonates. In fact, cardiovascular mortality is higher among former preterm adults than those born at term. This condition is referred to as cardiovascular perinatal programming. In the light of the above, an early, constant, and prolonged cardiological followup programme should be implemented in former preterm individuals. The aim of this paper was to perform a comprehensive literature review about two new emerging conditions predisposing to an increased cardiovascular risk: prematurity and low weight at birth.

Necrotizing Sialometaplasia of the Hard Palate in a Patient Treated with Topical Nonsteroidal Anti-Inflammatory Drug.

PubMed

Gatti, Alessandro; Broccardo, Emanuele; Poglio, Giuseppe; Benech, Arnaldo

2016-01-01

Necrotizing sialometaplasia is a rare, benign, self-limiting, necrotizing process involving the minor salivary glands, mainly the mucoserous glands of the hard palate. It is thought to be the result of an ischemic event of the vasculature supplying the salivary gland lobules. Some predisposing factors such as smoking, use of alcohol, denture wearing, recent surgery, traumatic injuries, respiratory infections, systemic diseases bulimia, and anorexia have been described. Herein we present a case of necrotizing sialometaplasia of the hard palate in a patient without known predisposing factors, in our opinion, resulting from the use of topical anti-inflammatory drug. After diagnosis, the patient underwent treatment with chlorhexidine gluconate and a full palatal acrylic guard to protect the exposed bone from food residues during meals. After the sixth week the lesion regressed.

Diabetes and Associated Complications in the South Asian Population

PubMed Central

Shah, Arti; Kanaya, Alka M.

2014-01-01

The increasing prevalence of diabetes in South Asians has significant health and economic implications. South Asians are predisposed to the development of diabetes due to biologic and lifestyle factors. Furthermore, they experience significant morbidity and mortality from complications of diabetes, most notably coronary artery disease, cerebrovascular disease and chronic kidney disease. Therefore, understanding the pathophysiology and genetics of diabetes risk factors and its associated complications in South Asians is paramount to curbing the diabetes epidemic. With this understanding, the appropriate screening, preventative and therapeutic strategies can be implemented and further developed. In this review, we discuss in detail the biologic and lifestyle factors that predispose South Asians to diabetes and review the epidemiology and pathophysiology of microvascular and macrovascular complications of diabetes in South Asians. We also review the ongoing and completed diabetes prevention and management studies in South Asians. PMID:24643902

Child behavioural problems and body size among 2-6 year old children predisposed to overweight. results from the "healthy start" study.

PubMed

Olsen, Nanna J; Pedersen, Jeanett; Händel, Mina N; Stougaard, Maria; Mortensen, Erik L; Heitmann, Berit L

2013-01-01

Psychological adversities among young children may be associated with childhood overweight and obesity. We examined if an increased level of child behavioural problems was associated with body size among a selected group of 2-6 year old children, who were all predisposed to develop overweight. Cross-sectional analyses were conducted using baseline data from the "Healthy Start" intervention study. A total of 3058 children were invited to participate, and data from 583 children who were all predisposed for obesity was analyzed. The Danish version of the Strengths and Difficulties Questionnaire (SDQ) was used to assess child stress by the SDQ Total Difficulties (SDQ-TD) score and the Prosocial Behavior (PSB) score. Height and weight were measured, and BMI z-scores were calculated. A direct, but non-significant linear trend was found between SDQ-TD score and BMI z-score (β = 0.021, p = 0.11). Having an SDQ-TD score above the 90(th) percentile was associated with BMI z-score (β = 0.36, p = 0.05). PSB score was not associated with BMI z-score. Analyses were adjusted for parental socioeconomic status, parental BMI, family structure, dietary factors, physical activity, and family stress level. The results suggested a threshold effect between SDQ-TD score and BMI z-score, where BMI z-score was associated with childhood behavioural problems only for those with the highest scores of SDQ-TD. No significant association between PSB score and BMI z-score was found.

SYN2 is an autism predisposing gene: loss-of-function mutations alter synaptic vesicle cycling and axon outgrowth

PubMed Central

Corradi, Anna; Fadda, Manuela; Piton, Amélie; Patry, Lysanne; Marte, Antonella; Rossi, Pia; Cadieux-Dion, Maxime; Gauthier, Julie; Lapointe, Line; Mottron, Laurent; Valtorta, Flavia; Rouleau, Guy A.; Fassio, Anna; Benfenati, Fabio; Cossette, Patrick

2014-01-01

An increasing number of genes predisposing to autism spectrum disorders (ASDs) has been identified, many of which are implicated in synaptic function. This ‘synaptic autism pathway’ notably includes disruption of SYN1 that is associated with epilepsy, autism and abnormal behavior in both human and mice models. Synapsins constitute a multigene family of neuron-specific phosphoproteins (SYN1-3) present in the majority of synapses where they are implicated in the regulation of neurotransmitter release and synaptogenesis. Synapsins I and II, the major Syn isoforms in the adult brain, display partially overlapping functions and defects in both isoforms are associated with epilepsy and autistic-like behavior in mice. In this study, we show that nonsense (A94fs199X) and missense (Y236S and G464R) mutations in SYN2 are associated with ASD in humans. The phenotype is apparent in males. Female carriers of SYN2 mutations are unaffected, suggesting that SYN2 is another example of autosomal sex-limited expression in ASD. When expressed in SYN2  knockout neurons, wild-type human Syn II fully rescues the SYN2 knockout phenotype, whereas the nonsense mutant is not expressed and the missense mutants are virtually unable to modify the SYN2 knockout phenotype. These results identify for the first time SYN2  as a novel predisposing gene for ASD and strengthen the hypothesis that a disturbance of synaptic homeostasis underlies ASD. PMID:23956174

Delayed celiac disease diagnosis predisposes to reduced quality of life and incremental use of health care services and medicines: A prospective nationwide study

PubMed Central

Fuchs, Valma; Kurppa, Kalle; Huhtala, Heini; Mäki, Markku; Kekkonen, Leila; Kaukinen, Katri

2018-01-01

Background Celiac disease is challenging to recognize, predisposing to long diagnostic delay. Currently, associated factors and significance of the delay remain obscure. Objective The objective of this article is to investigate associated sociodemographic risk factors and health consequences of diagnostic delay in celiac disease. Methods Altogether 611 patients were surveyed at diagnosis and after one year on a gluten-free diet regarding sociodemographic variables, well-being and use of medicines and health care services. Quality of life was measured by a validated Psychological General Well-Being (PGWB) questionnaire. The results were compared between patients with and without delayed (≥3 years) diagnosis. Results A total of 332 (54%) individuals reported a delay of ≥3 years. Associated with the delay were being a student or homemaker, but not gender, marital or occupational status, site of diagnosis or place of residence. Patients with the delay also had decreased self-perceived health and poorer PGWB scores compared to those without delay; in anxiety and general health this was seen even on a gluten-free diet. Days of sickness and doctor visits as well as use of drugs for dyspepsia and antidepressants were increased in the delay group both before and after diagnosis. Conclusion A delay in celiac disease diagnosis predisposes to reduced well-being and incremental use of medicines and health care services, both before diagnosis and one year after diagnosis. PMID:29881612

Visual consequences of electronic reader use: a pilot study.

PubMed

Maducdoc, Marlon M; Haider, Asghar; Nalbandian, Angèle; Youm, Julie H; Morgan, Payam V; Crow, Robert W

2017-04-01

With the increasing prevalence of electronic readers (e-readers) for vocational and professional uses, it is important to discover if there are visual consequences in the use of these products. There are no studies in the literature quantifying the incidence or severity of eyestrain, nor are there clinical characteristics that may predispose to these symptoms with e-reader use. The primary objective of this pilot study was to assess the degree of eyestrain associated with e-reader use compared to traditional paper format. The secondary outcomes of this study were to assess the rate of eyestrain associated with e-reader use and identify any clinical characteristics that may be associated with the development of eyestrain. Forty-four students were randomly assigned to study (e-reader iPAD) and control (print) groups. Participant posture, luminosity of the room, and reading distance from reading device were measured during a 1-h session for both groups. At the end of the session, questionnaires were administered to determine symptoms. Significantly higher rates of eyestrain (p = 0.008) and irritation (p = 0.011) were found among the iPAD study group as compared to the print 'control' group. The study group was also 4.9 times more likely to report severe eyestrain (95 % CI [1.4, 16.9]). No clinical characteristics predisposing to eyestrain could be identified. These findings conclude that reading on e-readers may induce increased levels of irritation and eyestrain. Predisposing factors, etiology, and potential remedial interventions remain to be determined.

Brain abscess in children.

PubMed

Atiq, Mehnaz; Ahmed, Umair Syed; Allana, Salman Saleem; Chishti, Khalid N

2006-05-01

Brain abscess is a serious life-threatening complication of several diseases. The objective of this study was to look at the clinical profile of patients, predisposing conditions, microbiology and outcome of children suffering from brain abscess. Thirty children aged less than 15 years were reviewed. There were 15 males and 15 females. The mean age of presentation was 5.6+/-4.4 years. The duration of illness at the time of admission was 17.6+/-24.6 days. Typically patients presented with fever, vomiting, headache and seizures. The predisposing conditions found were cyanotic congenital heart disease in 11 (37%) of children, meningitis in 6 (20%), septicemia in 7 (23%) and no underlying cause was found in 5 (17%) children. The most common microbe in children with cyanotic congenital heart disease was of the Streptococcus milleri group (52%). Computerized tomography confirmed the diagnosis and the most common location of the abscess was the parietal lobe of the cerebral hemisphere. All abscesses were large, more than 2 cm in diameter and were aspirated surgically. Excision was performed in 6 children. Five children expired, one due to a intracranial bleeding and the others due to severe cerebral edema and tentorial herniation. Complications were seen in 20 children and 16 had sequelae, hemiparesis in 11 and seizure disorder in 5. Brain abscess is a serious infection with poor outcome if diagnosed late. Delayed surgical drainage has high morbidity and mortality. The threshold for diagnosis should be low, particularly in children with a predisposing condition like cyanotic congenital heart disease.

Burkholderia gladioli sepsis in newborns.

PubMed

Dursun, Arzu; Zenciroglu, Aysegul; Karagol, Belma Saygili; Hakan, Nilay; Okumus, Nurullah; Gol, Nese; Tanir, Gonul

2012-10-01

Burkholderia gladioli is a rare cause of bacteremia and sepsis in the absence of such predisposing factors as chronic granulomatous disease, cystic fibrosis, and immunosuppression. Little is known about B. gladioli infection in newborns. The aim of this study was to present the features of B. gladioli infection in newborns. Clinicopathological characteristics, patterns of antimicrobial susceptibility, predisposing factors, and outcomes of B. gladioli bloodstream infection were retrospectively analyzed in newborns treated between 2008 and 2011. During the 3-year study period, B. gladioli was isolated from the blood cultures of 14 patients (3.7 per 1,000 admissions). In all, 5 (35.7 %) of the 14 cases had a positive blood culture at the time of initial admission. Primary diagnoses in the neonates were severe major congenital anomalies, congenital leukemia, prematurity with respiratory distress syndrome, pneumonia, and parapneumonic pleural effusion. In total, 10 (71.4 %) of the patients underwent ≥2 invasive procedures. The overall in-hospital mortality rate was 21.4 %, whereas the mortality rate due to B. gladioli infection was 7 %. B. gladioli might be a causative microorganism of both early neonatal and nosocomial sepsis in newborns. To the best of our knowledge, this is the first study on B. gladioli infection in newborns. Invasive procedures and severe major congenital anomalies may be predisposing factors for B. gladioli bloodstream infection in neonates. Although it appears to have low pathogenic potential and an insidious clinical course in newborns, resistance to antibiotics may be a potential problem. Mortality was primarily associated with underlying diseases.

Gas gangrene caused by clostridium perfringens involving the liver, spleen, and heart in a man 20 years after an orthotopic liver transplant: a case report.

PubMed

Kitterer, Daniel; Braun, Niko; Jehs, Margit C; Schulte, Bernhard; Alscher, M Dominik; Latus, Joerg

2014-04-01

Despite advances in immunosuppression and liver transplant in the past, mortality and morbidity caused by infections remain major problems. We present a 71-year-old man who was admitted to our internal intensive care unit with septicemia. Upon admission, he had poorly localized epigastric pain and fever of 2 days ' duration. Twenty years earlier, he had undergone an orthotopic liver transplant. Testing revealed a high C-reactive protein level, elevated liver enzymes, and an acute kidney injury. A computer tomography scan showed 2 circular, non--rim-enhancing, totally emphysematous intrahepatic lesions. Additionally, gas could be seen in the portal veins mainly, as well as in the biliary system, in the right auricle, and the splenic veins. To the best of our knowledge, he showed no malignant lesion or predisposing trauma. Empirically, treatment with broad-spectrum antibiotics was begun, and the patient was transferred to the operating suite. When surgery began, blood cultures revealed the presence of gram-positive bacilli, which were identified as Clostridium perfringens. Seven hours after the surgery, the patient developed asystole and died. In septic patients presenting with severe hemolysis, Clostridium perfringens infection must be considered in the absence of a malignant lesion or a predisposing trauma; a previous episode of gastroenteritis might be a predisposing trauma by impairing the barrier of the intestinal flora, leading to Clostridium perfringens infection.

Environmental Disruption of Circadian Rhythm Predisposes Mice to Osteoarthritis-Like Changes in Knee Joint

PubMed Central

Voigt, Robin M; Ellman, Michael B; Summa, Keith C; Vitaterna, Martha Hotz; Keshavarizian, Ali; Turek, Fred W; Meng, Qing-Jun; Stein, Gary S.; van Wijnen, Andre J.; Chen, Di; Forsyth, Christopher B; Im, Hee-Jeong

2015-01-01

Circadian rhythm dysfunction is linked to many diseases, yet pathophysiological roles in articular cartilage homeostasis and degenerative joint disease including osteoarthritis (OA) remains to be investigated in vivo. Here, we tested whether environmental or genetic disruption of circadian homeostasis predisposes to OA-like pathological changes. Male mice were examined for circadian locomotor activity upon changes in the light:dark (LD) cycle or genetic disruption of circadian rhythms. Wild-type (WT) mice were maintained on a constant 12 hour:12 hour LD cycle (12:12 LD) or exposed to weekly 12 hour phase shifts. Alternatively, male circadian mutant mice (ClockΔ19 or Csnk1etau mutants) were compared with age-matched WT littermates that were maintained on a constant 12:12 LD cycle. Disruption of circadian rhythms promoted osteoarthritic changes by suppressing proteoglycan accumulation, upregulating matrix-degrading enzymes and downregulating anabolic mediators in the mouse knee joint. Mechanistically, these effects involved activation of the PKCδ-ERK-RUNX2/NFκB and β-catenin signaling pathways, stimulation of MMP-13 and ADAMTS-5, as well as suppression of the anabolic mediators SOX9 and TIMP-3 in articular chondrocytes of phase-shifted mice. Genetic disruption of circadian homeostasis does not predispose to OA-like pathological changes in joints. Our results, for the first time, provide compelling in vivo evidence that environmental disruption of circadian rhythms is a risk factor for the development of OA-like pathological changes in the mouse knee joint. PMID:25655021

Cerebrospinal Fluid Leak at Percutaneous Exit of Ventricular Catheter as a Crucial Risk Factor for External Ventricular Drainage-Related Infection in Adult Neurosurgical Patients.

PubMed

Park, Jaechan; Choi, Yeon-Ju; Ohk, Boram; Chang, Hyun-Ha

2018-01-01

The placement of a ventricular catheter for temporary cerebrospinal fluid (CSF) diversion is associated with a considerable risk of CSF infection. The authors investigated the effect of a CSF leak on CSF-related infection and the predisposing factors for a CSF leak. Fifty-two patients who underwent external ventricular drainage (EVD) for acute hydrocephalus associated with a subarachnoid hemorrhage or intraventricular hemorrhage (IVH) were enrolled in this prospective study. A CSF leak-detection paper (small sterilized filter paper) was applied at the percutaneous catheter exit site to check for any bloody CSF leak. In addition, radiologic and clinical data were collected. Four of the 52 patients (7.7%) developed an EVD-related CSF infection from organisms including Staphylococcus epidermidis (n = 3) and Staphylococcus hominis (n = 1). A prolonged CSF leak >1 day was detected in 9 patients (17.3%) and revealed as a significant risk factor for CSF infection with a 44.4% positive predictive value. Moreover, an IVH >10 mL was found in 11 patients (21.2%) and revealed as a significant predisposing factor for a CSF leak at the percutaneous catheter exit. A prolonged CSF leak for >1 day at the percutaneous catheter exit site is a crucial risk factor for EVD-related CSF infection and an IVH >10 mL is a predisposing factor for a CSF leak. Copyright © 2017 Elsevier Inc. All rights reserved.

Chronic exposure to cocaine binging predisposes to an accelerated course of dilated cardiomyopathy in conscious dogs following rapid ventricular pacing.

PubMed

Parikh, Pratik; Nikolaidis, Lazaros A; Stolarski, Carol; Shen, You-Tang; Shannon, Richard P

2005-12-01

Despite extensive study, the extent to which cocaine use predisposes to cardiac injury remains unknown. We hypothesized that chronic cocaine binging would increase susceptibility to a subsequent cardiac insult, even in the absence of demonstrable effects on baseline hemodynamics. We studied progression of dilated cardiomyopathy (DCM) induced by rapid ventricular pacing (240 beats per minute) in five conscious, chronically instrumented dogs, after exposure to repetitive cocaine binging (COC) in the form of four consecutive 1 mg/kg i.v. boluses daily for 8 days, to simulate human cocaine abuse. We compared the results with nine control dogs (CON) undergoing the exact pacing protocol, without prior cocaine exposure. Baseline hemodynamics were not significantly altered by chronic cocaine exposure. Following 2 weeks of pacing, COC dogs exhibited accelerated progression to DCM, depressed plasma nitric oxide levels (CON, 17 +/- 2 microM; COC, 10 +/- 2 microM, p < 0.05), and a significantly greater increase in plasma epinephrine (CON, 33 +/- 6 pg/ml; COC, 104 +/- 24 pg/ml). After only 2 weeks of pacing, COC dogs demonstrated progressive DCM of a magnitude comparable with end-stage pacing-induced DCM. Chronic cocaine binging increases susceptibility to a subsequent myocardial insult and accelerates progression of DCM in conscious dogs following rapid pacing. These data suggest that although chronic cocaine use alone may not affect myocardial function, it predisposes to greater susceptibility to a superimposed insult.

Neonatal overfeeding attenuates acute central pro-inflammatory effects of short-term high fat diet

PubMed Central

Cai, Guohui; Dinan, Tara; Barwood, Joanne M.; De Luca, Simone N.; Soch, Alita; Ziko, Ilvana; Chan, Stanley M. H.; Zeng, Xiao-Yi; Li, Songpei; Molero, Juan; Spencer, Sarah J.

2015-01-01

Neonatal obesity predisposes individuals to obesity throughout life. In rats, neonatal overfeeding also leads to early accelerated weight gain that persists into adulthood. The phenotype is associated with dysfunction in a number of systems including paraventricular nucleus of the hypothalamus (PVN) responses to psychological and immune stressors. However, in many cases weight gain in neonatally overfed rats stabilizes in early adulthood so the animal does not become more obese as it ages. Here we examined if neonatal overfeeding by suckling rats in small litters predisposes them to exacerbated metabolic and central inflammatory disturbances if they are also given a high fat diet in later life. In adulthood we gave the rats normal chow, 3 days, or 3 weeks high fat diet (45% kcal from fat) and measured peripheral indices of metabolic disturbance. We also investigated hypothalamic microglial changes, as an index of central inflammation, as well as PVN responses to lipopolysaccharide (LPS). Surprisingly, neonatal overfeeding did not predispose rats to the metabolic effects of a high fat diet. Weight changes and glucose metabolism were unaffected by the early life experience. However, short term (3 day) high fat diet was associated with more microglia in the hypothalamus and a markedly exacerbated PVN response to LPS in control rats; effects not seen in the neonatally overfed. Our findings indicate neonatally overfed animals are not more susceptible to the adverse metabolic effects of a short-term high fat diet but may be less able to respond to the central effects. PMID:25628527

Bronchopulmonary Actinomycosis Associated With Hiatal Hernia

PubMed Central

Andreani, Alessandro; Cavazza, Alberto; Marchioni, Alessandro; Richeldi, Luca; Paci, Massimiliano; Rossi, Giulio

2009-01-01

OBJECTIVES: To describe clinicoradiologic and histopathologic features of bronchopulmonary actinomycosis and to determine whether hiatal hernia (HH) is a potential predisposing factor for bronchopulmonary actinomycosis. PATIENTS AND METHODS: We reviewed the medical charts of 10 patients who had bronchopulmonary actinomycosis between November 1, 2002, and January 31, 2008. Complete clinical data, radiologic studies (chest radiographs and computed tomographic scans), and histopathologic features were assessed to investigate clinical manifestations and predisposing factors related to bronchopulmonary actinomycosis. RESULTS: The series consisted of 6 men and 4 women, with a mean age of 63.5 years; 8 of the patients were smokers. Cough and fever were the most common symptoms. Chest imaging showed mass-like consolidation in 4 patients, bronchial thickening or lung atelectasis with pleural thickening in 2 patients each, and perihilar irregular mass or multiple bilateral nodules in 1 patient each. Primary or metastatic lung cancer was suspected clinically in 8 of the 10 patients. Foreign body-related endobronchial actinomycosis was diagnosed in 6 patients, 5 of whom had HH; only 1 had gastroesophageal reflux-related symptoms. Because of bronchial obstruction, rigid bronchoscopy was performed in 3 patients, lobectomy in 2, and atypical resection in 1. Antibiotic therapy with amoxicillin was given to all patients, with resolution of actinomycosis. CONCLUSION: Bronchopulmonary actinomycosis is a rare condition that mimics pulmonary malignancy on clinical and radiologic grounds. Diagnosis relies on an accurate patient history and histopathologic examination. Although further confirmation is required, esophageal HH appears to be a potential predisposing factor. PMID:19181645

Pediatric stroke: clinical characteristics, acute care utilization patterns, and mortality.

PubMed

Statler, Kimberly D; Dong, Li; Nielsen, Denise M; Bratton, Susan L

2011-04-01

Acute care utilization patterns are not well described but may help inform care coordination and treatment for pediatric stroke. The Kids Inpatient Database was queried to describe demographics and clinical characteristics of children with stroke, compare acute care utilization for hemorrhagic vs. ischemic stroke and Children's vs. non-Children's Hospitals, and identify factors associated with aggressive care and in-hospital mortality. Using a retrospective cohort of children hospitalized with stroke, demographics, predisposing conditions, and intensive (mechanical ventilation, advanced monitoring, and blood product administration) or aggressive (pharmacological therapy and/or invasive interventions) care were compared by stroke and hospital types. Factors associated with aggressive care or in-hospital mortality were explored using logistic regression. Hemorrhagic stroke comprised 43% of stroke discharges, was more common in younger children, and carried greater mortality. Ischemic stroke was more common in older children and more frequently associated with a predisposing condition. Rates of intensive and aggressive care were low (30% and 15%), similar by stroke type, and greater at Children's Hospitals. Older age, hemorrhagic stroke, predisposing condition, and treatment at a Children's Hospital were associated with aggressive care. Hemorrhagic stroke and aggressive care were associated with in-hospital mortality. Acute care utilization is similar by stroke type but both intensive and aggressive care are more common at Children's Hospitals. Mortality remains relatively high after pediatric stroke. Widespread implementation of treatment guidelines improved outcomes in adult stroke. Adoption of recently published treatment recommendations for pediatric stroke may help standardize care and improve outcomes.

In vitro fertilization-induced pregnancies predispose to gastroesophageal reflux disease

PubMed Central

Kitapcioglu, Gul; Tavmergen Goker, Ege; Sahin, Gulnaz; Bor, Serhat

2015-01-01

Background Women conceiving following in vitro fertilization (IVF) likely have a variety of risk factors that predispose them to gastroesophageal reflux disease (GERD) in the future. Objective We aimed to investigate whether pregnancy through IVF may predispose to subsequent GERD compared with pregnancies without IVF. We also evaluate whether twin IVF pregnancies lead to additional risk for having GERD compared with singleton IVF pregnancies. Methods A validated reflux questionnaire was administered to 156 women with singleton (n = 102) or twin (n = 54) IVF birth (IVF group) and 111 women with a naturally conceived singleton birth (control group). All women included in the study were primiparas who had given birth at least 1 year prior to data collection. The diagnosis of GERD was based on the occurrence of typical symptoms (heartburn, regurgitation, or both) at least once a week. Results The prevalence of GERD was 13.5% and 4.5% in IVF and control groups (p = 0.015); in the IVF group, this was slightly higher, but not statistically significant, in women with twin compared with singleton pregnancies (14.8% vs. 12.7%, p = 0.749). Logistic regression analysis showed that IVF was strongly associated with subsequent GERD (OR, 3.30; 95% CI 1.20–9.04; p = 0.02). Conclusion The risk of developing GERD at least 1 year after delivery increased following IVF. Long-term follow-up studies are required to determine whether therapy during pregnancy can prevent this risk. PMID:27087950

Three New Alpha1-Antitrypsin Deficiency Variants Help to Define a C-Terminal Region Regulating Conformational Change and Polymerization

PubMed Central

Fra, Anna M.; Gooptu, Bibek; Ferrarotti, Ilaria; Miranda, Elena; Scabini, Roberta; Ronzoni, Riccardo; Benini, Federica; Corda, Luciano; Medicina, Daniela; Luisetti, Maurizio; Schiaffonati, Luisa

2012-01-01

Alpha1-antitrypsin (AAT) deficiency is a hereditary disorder associated with reduced AAT plasma levels, predisposing adults to pulmonary emphysema. The most common genetic AAT variants found in patients are the mildly deficient S and the severely deficient Z alleles, but several other pathogenic rare alleles have been reported. While the plasma AAT deficiency is a common trait of the disease, only a few AAT variants, including the prototypic Z AAT and some rare variants, form cytotoxic polymers in the endoplasmic reticulum of hepatocytes and predispose to liver disease. Here we report the identification of three new rare AAT variants associated to reduced plasma levels and characterize their molecular behaviour in cellular models. The variants, called Mpisa (Lys259Ile), Etaurisano (Lys368Glu) and Yorzinuovi (Pro391His), showed reduced secretion compared to control M AAT, and accumulated to different extents in the cells as ordered polymeric structures resembling those formed by the Z variant. Structural analysis of the mutations showed that they may facilitate polymerization both by loosening ‘latch’ interactions constraining the AAT reactive loop and through effects on core packing. In conclusion, the new AAT deficiency variants, besides increasing the risk of lung disease, may predispose to liver disease, particularly if associated with the common Z variant. The new mutations cluster structurally, thus defining a region of the AAT molecule critical for regulating its conformational state. PMID:22723858

The mycotoxin deoxynivalenol predisposes for the development of Clostridium perfringens-induced necrotic enteritis in broiler chickens.

PubMed

Antonissen, Gunther; Van Immerseel, Filip; Pasmans, Frank; Ducatelle, Richard; Haesebrouck, Freddy; Timbermont, Leen; Verlinden, Marc; Janssens, Geert Paul Jules; Eeckhaut, Venessa; Eeckhout, Mia; De Saeger, Sarah; Hessenberger, Sabine; Martel, An; Croubels, Siska

2014-01-01

Both mycotoxin contamination of feed and Clostridium perfringens-induced necrotic enteritis have an increasing global economic impact on poultry production. Especially the Fusarium mycotoxin deoxynivalenol (DON) is a common feed contaminant. This study aimed at examining the predisposing effect of DON on the development of necrotic enteritis in broiler chickens. An experimental Clostridium perfringens infection study revealed that DON, at a contamination level of 3,000 to 4,000 µg/kg feed, increased the percentage of birds with subclinical necrotic enteritis from 20±2.6% to 47±3.0% (P<0.001). DON significantly reduced the transepithelial electrical resistance in duodenal segments (P<0.001) and decreased duodenal villus height (P = 0.014) indicating intestinal barrier disruption and intestinal epithelial damage, respectively. This may lead to an increased permeability of the intestinal epithelium and decreased absorption of dietary proteins. Protein analysis of duodenal content indeed showed that DON contamination resulted in a significant increase in total protein concentration (P = 0.023). Furthermore, DON had no effect on in vitro growth, alpha toxin production and netB toxin transcription of Clostridium perfringens. In conclusion, feed contamination with DON at concentrations below the European maximum guidance level of 5,000 µg/kg feed, is a predisposing factor for the development of necrotic enteritis in broilers. These results are associated with a negative effect of DON on the intestinal barrier function and increased intestinal protein availability, which may stimulate growth and toxin production of Clostridium perfringens.

Pivotal Role of Inosine Triphosphate Pyrophosphatase in Maintaining Genome Stability and the Prevention of Apoptosis in Human Cells

PubMed Central

Lopez-Bertoni, Hernando; Luo, Xu; Pavlov, Youri I.

2012-01-01

Pure nucleotide precursor pools are a prerequisite for high-fidelity DNA replication and the suppression of mutagenesis and carcinogenesis. ITPases are nucleoside triphosphate pyrophosphatases that clean the precursor pools of the non-canonical triphosphates of inosine and xanthine. The precise role of the human ITPase, encoded by the ITPA gene, is not clearly defined. ITPA is clinically important because a widespread polymorphism, 94C>A, leads to null ITPase activity in erythrocytes and is associated with an adverse reaction to thiopurine drugs. We studied the cellular function of ITPA in HeLa cells using the purine analog 6-N hydroxylaminopurine (HAP), whose triphosphate is also a substrate for ITPA. In this study, we demonstrate that ITPA knockdown sensitizes HeLa cells to HAP-induced DNA breaks and apoptosis. The HAP-induced DNA damage and cytotoxicity observed in ITPA knockdown cells are rescued by an overexpression of the yeast ITPase encoded by the HAM1 gene. We further show that ITPA knockdown results in elevated mutagenesis in response to HAP treatment. Our studies reveal the significance of ITPA in preventing base analog-induced apoptosis, DNA damage and mutagenesis in human cells. This implies that individuals with defective ITPase are predisposed to genome damage by impurities in nucleotide pools, which is drastically augmented by therapy with purine analogs. They are also at an elevated risk for degenerative diseases and cancer. PMID:22384212

The gut microbiota and metabolic disease: current understanding and future perspectives.

PubMed

Arora, T; Bäckhed, F

2016-10-01

The human gut microbiota has been studied for more than a century. However, of nonculture-based techniques exploiting next-generation sequencing for analysing the microbiota, development has renewed research within the field during the past decade. The observation that the gut microbiota, as an environmental factor, contributes to adiposity has further increased interest in the field. The human microbiota is affected by the diet, and macronutrients serve as substrates for many microbially produced metabolites, such as short-chain fatty acids and bile acids, that may modulate host metabolism. Obesity predisposes towards type 2 diabetes and cardiovascular disease. Recently, it has been established that levels of butyrate-producing bacteria are reduced in patients with type 2 diabetes, whereas levels of Lactobacillus sp. are increased. Recent data suggest that the reduced levels of butyrate-producing bacteria might be causally linked to type 2 diabetes. Bariatric surgery, which promotes long-term weight loss and diabetes remission, alters the gut microbiota in both mice and humans. Furthermore, by transferring the microbiota from postbariatric surgery patients to mice, it has been demonstrated that an altered microbiota may contribute to the improved metabolic phenotype following this intervention. Thus, greater understanding of alterations of the gut microbiota, in combination with dietary patterns, may provide insights into how the gut microbiota contributes to disease progression and whether it can be exploited as a novel diagnostic, prognostic and therapeutic target. © 2016 The Association for the Publication of the Journal of Internal Medicine.

INF-γ encoding plasmid administration triggers bone loss and disrupts bone marrow microenvironment.

PubMed

Agas, Dimitrios; Gusmão Silva, Guilherme; Laus, Fulvio; Marchegiani, Andrea; Capitani, Melania; Vullo, Cecilia; Catone, Giuseppe; Lacava, Giovanna; Concetti, Antonio; Marchetti, Luigi; Sabbieti, Maria Giovanna

2017-02-01

IFN-γ is a pleotropic cytokine produced in the bone microenvironment. Although IFN-γ is known to play a critical role on bone remodeling, its function is not fully elucidated. Consistently, outcomes on the effects of IFN-γ recombinant protein on bone loss are contradictory among reports. In our work we explored, for the first time, the role of IFN-γ encoding plasmid (pIFN-γ) in a mouse model of osteopenia induced by ovariectomy and in the sham-operated counterpart to estimate its effects in skeletal homeostasis. Ovariectomy produced a dramatic decrease of bone mineral density (BMD). pINF-γ injected mice showed a pathologic bone and bone marrow phenotype; the disrupted cortical and trabecular bone microarchitecture was accompanied by an increased release of pro-inflammatory cytokine by bone marrow cells. Moreover, mesenchymal stem cells' (MSCs) commitment to osteoblast was found impaired, as evidenced by the decline of osterix-positive (Osx + ) cells within the mid-diaphyseal area of femurs. For instance, a reduction and redistribution of CXCL12 cells have been found, in accordance with bone marrow morphological alterations. As similar effects were observed both in sham-operated and in ovariectomized mice, our studies proved that an increased IFN-γ synthesis in bone marrow might be sufficient to induce inflammatory and catabolic responses even in the absence of pathologic predisposing substrates. In addition, the obtained data might raise questions about pIFN-γ's safety when it is used as vaccine adjuvant. © 2017 Society for Endocrinology.

Emerging targets for addiction neuropharmacology: From mechanisms to therapeutics.

PubMed

Ubaldi, Massimo; Cannella, Nazzareno; Ciccocioppo, Roberto

2016-01-01

Drug abuse represents a considerable burden of disease and has enormous economic impacts on societies. Over the years, few medications have been developed for clinical use. Their utilization is endowed with several limitations, including partial efficacy or significant side effects. On the other hand, the successful advancement of these compounds provides an important proof of concept for the feasibility of drug development programs in addiction. In recent years, a wealth of information has been generated on the psychological mechanisms, genetic or epigenetic predisposing factors, and neurobiological adaptations induced by drug consumption that interact with each other to contribute to disease progression. It is now clear that addiction develops through phases, from initial recreational use to excessive consumption and compulsive drug seeking, with a shift from positive to negative reinforcement driving motivated behaviors. A greater understanding of these mechanisms has opened new vistas in drug development programs. Researchers' attention has been shifted from investigation of classical targets associated with reward to biological substrates responsible for negative reinforcement, impulse loss of control, and maladaptive mechanisms resulting from protracted drug use. From this research, several new biological targets for the development of innovative therapies have started to emerge. This chapter offers an overview of targets currently under scrutiny for the development of new medications for addiction. This work is not exhaustive but rather it provides a few examples of how this research has advanced in recent years by virtue of studies carried out in our laboratory. © 2016 Elsevier B.V. All rights reserved.

Murine Electrophysiological Models of Cardiac Arrhythmogenesis

PubMed Central

2016-01-01

Cardiac arrhythmias can follow disruption of the normal cellular electrophysiological processes underlying excitable activity and their tissue propagation as coherent wavefronts from the primary sinoatrial node pacemaker, through the atria, conducting structures and ventricular myocardium. These physiological events are driven by interacting, voltage-dependent, processes of activation, inactivation, and recovery in the ion channels present in cardiomyocyte membranes. Generation and conduction of these events are further modulated by intracellular Ca2+ homeostasis, and metabolic and structural change. This review describes experimental studies on murine models for known clinical arrhythmic conditions in which these mechanisms were modified by genetic, physiological, or pharmacological manipulation. These exemplars yielded molecular, physiological, and structural phenotypes often directly translatable to their corresponding clinical conditions, which could be investigated at the molecular, cellular, tissue, organ, and whole animal levels. Arrhythmogenesis could be explored during normal pacing activity, regular stimulation, following imposed extra-stimuli, or during progressively incremented steady pacing frequencies. Arrhythmic substrate was identified with temporal and spatial functional heterogeneities predisposing to reentrant excitation phenomena. These could arise from abnormalities in cardiac pacing function, tissue electrical connectivity, and cellular excitation and recovery. Triggering events during or following recovery from action potential excitation could thereby lead to sustained arrhythmia. These surface membrane processes were modified by alterations in cellular Ca2+ homeostasis and energetics, as well as cellular and tissue structural change. Study of murine systems thus offers major insights into both our understanding of normal cardiac activity and its propagation, and their relationship to mechanisms generating clinical arrhythmias. PMID:27974512

A Review of Gaucher Disease Pathophysiology, Clinical Presentation and Treatments

PubMed Central

Stirnemann, Jérôme; Belmatoug, Nadia; Camou, Fabrice; Serratrice, Christine; Froissart, Roseline; Caillaud, Catherine; Levade, Thierry; Astudillo, Leonardo; Serratrice, Jacques; Brassier, Anaïs; Rose, Christian; Billette de Villemeur, Thierry; Berger, Marc G.

2017-01-01

Gaucher disease (GD, ORPHA355) is a rare, autosomal recessive genetic disorder. It is caused by a deficiency of the lysosomal enzyme, glucocerebrosidase, which leads to an accumulation of its substrate, glucosylceramide, in macrophages. In the general population, its incidence is approximately 1/40,000 to 1/60,000 births, rising to 1/800 in Ashkenazi Jews. The main cause of the cytopenia, splenomegaly, hepatomegaly, and bone lesions associated with the disease is considered to be the infiltration of the bone marrow, spleen, and liver by Gaucher cells. Type-1 Gaucher disease, which affects the majority of patients (90% in Europe and USA, but less in other regions), is characterized by effects on the viscera, whereas types 2 and 3 are also associated with neurological impairment, either severe in type 2 or variable in type 3. A diagnosis of GD can be confirmed by demonstrating the deficiency of acid glucocerebrosidase activity in leukocytes. Mutations in the GBA1 gene should be identified as they may be of prognostic value in some cases. Patients with type-1 GD—but also carriers of GBA1 mutation—have been found to be predisposed to developing Parkinson’s disease, and the risk of neoplasia associated with the disease is still subject to discussion. Disease-specific treatment consists of intravenous enzyme replacement therapy (ERT) using one of the currently available molecules (imiglucerase, velaglucerase, or taliglucerase). Orally administered inhibitors of glucosylceramide biosynthesis can also be used (miglustat or eliglustat). PMID:28218669

Breast Cancer and the Environment Research Program

Cancer.gov

The Breast Cancer and the Environment Research Program supports a multidisciplinary network of scientists, clinicians, and community partners to examine the effects of environmental exposures that may predispose a woman to breast cancer throughout her life.

Genome sequencing of Ewing sarcoma patients reveals genetic predisposition | Center for Cancer Research

Cancer.gov

The largest and most comprehensive genomic analysis of individuals with Ewing sarcoma performed to date reveals that some patients are genetically predisposed to developing the cancer.  Learn more...

Blueberries and Metabolic Syndrome

USDA-ARS?s Scientific Manuscript database

Metabolic Syndrome is a cluster of metabolic disorders that increase the risk of cardiovascular diseases. Type 2 diabetes, elevated blood pressure, and atherogenic dyslipidemia are among the metabolic alterations that predispose the individual to several adverse cardiovascular complications. The hea...

Predisposition Factors in Anorexia Nervosa.

ERIC Educational Resources Information Center

Nagel, K. L.; Jones, Karen H.

1992-01-01

Reviews literature concerned with investigating psychiatric disturbances and genetic variables hypothesized as predisposing factors in etiology of anorexia nervosa. Gives particular emphasis to research which discusses association between anorexia nervosa and depression. Reviews psychopharmacological evidence and family genetics studies. Offers…

Gingival recession: its causes and types, and the importance of orthodontic treatment

PubMed Central

Jati, Ana Suzy; Furquim, Laurindo Zanco; Consolaro, Alberto

2016-01-01

abstract Gingival recession has direct causes and predisposing factors. Orthodontic treatment is able to prevent recession and even contribute to its treatment, with or without periodontal approach, depending on the type and severity of gingival tissue damage. There is no evidence on the fact that orthodontic treatment alone might induce gingival recession, although it might lead the affected teeth (usually mandibular incisors or maxillary canines) to be involved in situations that act as predisposing factors, allowing direct causes to act and, therefore, trigger recession, especially when the buccal bone plate is very thin or presents with dehiscence. Several aspects regarding the relationship between orthodontic treatment and gingival recession have been addressed, and so has the importance of the periosteum to the mechanism of gingival recession formation. Clinical as well as experimental trials on the subject would help to clarify this matter, of which understanding is not very deep in the related literature. PMID:27409650

Haploinsufficiency of the genes encoding the tumor suppressor Pten predisposes zebrafish to hemangiosarcoma.

PubMed

Choorapoikayil, Suma; Kuiper, Raoul V; de Bruin, Alain; den Hertog, Jeroen

2012-03-01

PTEN is an essential tumor suppressor that antagonizes Akt/PKB signaling. The zebrafish genome encodes two Pten genes, ptena and ptenb. Here, we report that zebrafish mutants that retain a single wild-type copy of ptena or ptenb (ptena(+/-)ptenb(-/-) or ptena(-/-)ptenb(+/-)) are viable and fertile. ptena(+/-)ptenb(-/-) fish develop tumors at a relatively high incidence (10.2%) and most tumors developed close to the eye (26/30). Histopathologically, the tumor masses were associated with the retrobulbar vascular network and diagnosed as hemangiosarcomas. A single tumor was identified in 42 ptena(-/-)ptenb(+/-) fish and was also diagnosed as hemangiosarcoma. Immunohistochemistry indicated that the tumor cells in ptena(+/-)ptenb(-/-) and ptena(-/-)ptenb(+/-) fish proliferated rapidly and were of endothelial origin. Akt/PKB signaling was activated in the tumors, whereas Ptena was still detected in tumor tissue from ptena(+/-)ptenb(-/-) zebrafish. We conclude that haploinsufficiency of the genes encoding Pten predisposes to hemangiosarcoma in zebrafish.

Frequency of 3' VNTR Polymorphism in the Dopamine Transporter Gene SLC6A3 in Humans Predisposed to Antisocial Behavior.

PubMed

Cherepkova, E V; Aftanas, L I; Maksimov, N; Menshanov, P N

2016-11-01

Predisposition to antisocial behavior can be related to the presence of certain polymorphic variants of genes encoding dopaminergic system proteins. We studied the frequencies of allele variants and genotypes of variable number tandem repeat polymorphism in 3' untranslated region (3' VTNR) of the dopaminergic transporter SLC6A3 gene in Caucasian men committed socially dangerous violent and non-violent crimes. Alleles with 9 and 10 repeats were most frequent in both the control group and group of men predisposed to antisocial behavior. At the same time, the 10/10 genotype was more frequently observed in the group of men prone to antisocial non-violent behavior. Hence, the presence of certain variants of 3' VTNR polymorphism of SLC6A3 gene in men is associated with predisposition to certain forms of antisocial behavior.

Surgical management of recurrent urinary tract infections: a review

PubMed Central

Bergamin, Paul A.

2017-01-01

There are many causes of recurrent urinary tract infections (rUTI) which are amenable to surgical management. This usually follows a lengthy trial of conservative management. Aetiological classification of rUTI requiring surgical management may be divided into congenital or acquired. Predisposing factors are classified into two groups; those providing a source for organisms, or by maintaining favourable conditions for the proliferation of organisms. Sources of infections include calculi, fistulae or abscesses. Conditions which predispose to bacterial proliferation include malignancies, foreign bodies, high post void residuals, and neuropathic bladders. Removal of identified sources, treating the obstruction, and improving urinary drainage, are all goals of surgical management. Surgical options for rUTI management can range from minimally invasive procedures such as endoscopic or percutaneous, through to more invasive requiring laparoscopic or an open approach. Surgery remains a very important and viable solution. PMID:28791234

The stress and migraine interaction.

PubMed

Sauro, Khara M; Becker, Werner J

2009-10-01

There are several ways in which stress may interact with migraine in those predisposed to migraine attacks. These interactions may result from biochemical changes related to the physiological stress response, as, for example, the release of corticotrophin releasing hormone, or from changes induced by the psychological response to stressors. Stress is the factor listed most often by migraine sufferers as a trigger for their attacks, but in addition there is evidence that stress can help initiate migraine in those predisposed to the disorder, and may also contribute to migraine chronification. Migraine attacks themselves can act as a stressor, thereby potentially leading to a vicious circle of increasing migraine frequency. Since the important factor in the stress-migraine interaction is likely the individual's responses to stressors, rather than the stressors themselves, the acquisition of effective stress management skills has the potential to reduce the impact of stressors on those with migraine.

Rumen conditions that predispose cattle to pasture bloat.

PubMed

Majak, W; Howarth, R E; Cheng, K J; Hall, J W

1983-08-01

Rumen contents from the dorsal sac were examined before alfalfa ingestion to determine factors that predispose cattle to pasture bloat. Chlorophyll concentration, buoyancy of particulate matter, and rates of gas production were significantly higher in cattle that subsequently bloated than in those that did not. Higher chlorophyll in bloat cases indicated accumulation of suspended chloroplast particles in the dorsal sac, perhaps due to increased buoyancy of the particulate matter. The higher fermentation rates (in the presence of glucose) suggested that the latent capacity for gas production was due to microbial colonization of suspended feed particles. Chlorophyll 4 h after feeding was also higher in bloated as compared to unbloated animals. In short, the microbial colonization and retention of particulate matter provided active inocula for promoting rapid legume digestion. Consequently, gas production was enhanced when feeding commenced, but the fermentation gases were trapped by the buoyant, frothy ingesta, resulting in the condition of pasture bloat.

Diabetes and associated complications in the South Asian population.

PubMed

Shah, Arti; Kanaya, Alka M

2014-05-01

The rising prevalence of diabetes in South Asians has significant health and economic implications. South Asians are predisposed to the development of diabetes due to biologic causes which are exacerbated by lifestyle and environmental factors. Furthermore, they experience significant morbidity and mortality from complications of diabetes, most notably coronary artery disease, cerebrovascular disease, and chronic kidney disease. Therefore, understanding the pathophysiology and genetics of diabetes risk factors and its associated complications in South Asians is paramount to curbing the diabetes epidemic. With this understanding, the appropriate screening, preventative and therapeutic strategies can be implemented and further developed. In this review, we discuss in detail the biologic and lifestyle factors that predispose South Asians to diabetes and review the epidemiology and pathophysiology of microvascular and macrovascular complications of diabetes in South Asians. We also review the ongoing and completed diabetes prevention and management studies in South Asians.

Application of the PRECEDE model to understanding mental health promoting behaviors in Hong Kong.

PubMed

Mo, Phoenix K H; Mak, Winnie W S

2008-08-01

The burdens related to mental illness have been increasingly recognized in many countries. Nevertheless, research in positive mental health behaviors remains scarce. This study utilizes the Predisposing, Reinforcing, and Enabling Causes in Education Diagnosis and Evaluation (PRECEDE) model to identify factors associated with mental health promoting behaviors and to examine the effects of these behaviors on mental well-being and quality of life among 941 adults in Hong Kong. Structural equation modeling shows that sense of coherence (predisposing factor), social support (reinforcing factor), and daily hassles (enabling factor) are significantly related to mental health promoting behaviors, which are associated with mental well-being and quality of life. Results of bootstrap analyses confirm the mediating role of mental health promoting behaviors on well-being and quality of life. The study supports the application of the PRECEDE model in understanding mental health promoting behaviors and demonstrates its relationships with well-being and quality of life.

Risk Factors for Heat-related Illness in U.S. Workers: An OSHA Case Series.

PubMed

Tustin, Aaron W; Cannon, Dawn L; Arbury, Sheila B; Thomas, Richard J; Hodgson, Michael J

2018-05-30

The aim of this study was to describe risk factors for heat-related illness (HRI) in U.S. workers. We reviewed a subset of HRI enforcement investigations conducted by the Occupational Safety and Health Administration (OSHA) from 2011 through 2016. We assessed characteristics of the workers, employers, and events. We stratified cases by severity to assess whether risk factors were more prevalent in fatal HRIs. We analyzed 38 investigations involving 66 HRIs. Many workers had predisposing medical conditions or used predisposing medications. Comorbidities were more prevalent in workers who died. Most (73%) fatal HRIs occurred during the first week on the job. Common clinical findings in heat stroke cases included multiorgan failure, muscle breakdown, and systemic inflammation. Severe HRI is more likely when personal susceptibilities coexist with work-related and environmental risk factors. Almost all HRIs occur when employers do not adhere to preventive guidelines.

Right-sided infective endocarditis: recent epidemiologic changes

PubMed Central

Yuan, Shi-Min

2014-01-01

Background: Infective endocarditis (IE) has been increasingly reported, however, little is available regarding recent development of right-sided IE. Methods: Right-sided IE was comprehensively analyzed based on recent 5⅓-year literature. Results: Portal of entry, implanted foreign material, and repaired congenital heart defects were the main predisposing risk factors. Vegetation size on the right-sided valves was much smaller than those beyond the valves. Multiple logistic regression analysis revealed that predisposing risk factors, and vegetation size and locations were independent predictive risks of patients’ survival. Conclusions: Changes of right-sided IE in the past 5⅓ years included younger patient age, and increased vegetation size, but still prominent Staphylococcus aureus infections. Complication spectrum has changed into more valve insufficiency, more embolic events, reduced abscess formation, and considerably decreased valve perforations. With effective antibiotic regimens, prognoses of the patients seemed to be better than before. PMID:24482708

Gene-environment interactions controlling energy and glucose homeostasis and the developmental origins of obesity.

PubMed

Bouret, Sebastien; Levin, Barry E; Ozanne, Susan E

2015-01-01

Obesity and type 2 diabetes mellitus (T2DM) often occur together and affect a growing number of individuals in both the developed and developing worlds. Both are associated with a number of other serious illnesses that lead to increased rates of mortality. There is likely a polygenic mode of inheritance underlying both disorders, but it has become increasingly clear that the pre- and postnatal environments play critical roles in pushing predisposed individuals over the edge into a disease state. This review focuses on the many genetic and environmental variables that interact to cause predisposed individuals to become obese and diabetic. The brain and its interactions with the external and internal environment are a major focus given the prominent role these interactions play in the regulation of energy and glucose homeostasis in health and disease. Copyright © 2015 the American Physiological Society.

A novel haplotype of spinocerebellar ataxia type 6 contributes to the highest prevalence in western Japan.

PubMed

Terasawa, Hideo; Oda, Masaya; Morino, Hiroyuki; Miyachi, Takafumi; Izumi, Yuishin; Maruyama, Hirofumi; Matsumoto, Masayasu; Kawakami, Hideshi

2004-03-25

The highest prevalence rate of spinocerebellar ataxia type 6 (SCA6) in the worldwide population is in the Chugoku and Kansai areas of Western Japan, but the reason of this geographic characteristics is unclear. We investigated the predisposing haplotypes and their geographic distribution. Genotyping of five microsatellite markers and three single nucleotide polymorphisms linked to the CACNA1A gene in 150 Japanese SCA6 patients from unrelated 118 families revealed three major haplotypes, carrying a pool of one common haplotype core. A founder chromosome was thought to have historically diverged into at least three types. One of the major haplotypes newly identified showed a strong geographical cluster around the Seto Inland Sea in the Chugoku and Kansai areas of Western Japan, whereas the others were widely distributed throughout Japan. The distribution of predisposing haplotypes contributes to the geographical differences in prevalence of SCA6.

Effects of Obesity on Cardiovascular Hemodynamics, Cardiac Morphology, and Ventricular Function.

PubMed

Alpert, Martin A; Omran, Jad; Bostick, Brian P

2016-12-01

Obesity produces a variety of hemodynamic alterations that may cause changes in cardiac morphology which predispose to left and right ventricular dysfunction. Various neurohormonal and metabolic alterations commonly associated with obesity may contribute to these abnormalities of cardiac structure and function. These changes in cardiovascular hemodynamics, cardiac morphology, and ventricular function may, in severely obese patients, predispose to heart failure, even in the absence of other forms of heart disease (obesity cardiomyopathy). In normotensive obese patients, cardiac involvement is commonly characterized by elevated cardiac output, low peripheral vascular resistance, and increased left ventricular (LV) end-diastolic pressure. Sleep-disordered breathing may lead to pulmonary arterial hypertension and, in association with left heart failure, may contribute to elevation of right heart pressures. These alterations, in association with various neurohormonal and metabolic abnormalities, may produce LV hypertrophy; impaired LV diastolic function; and less commonly, LV systolic dysfunction. Many of these alterations are reversible with substantial voluntary weight loss.

[Pathogenesis of adhesions formation after intraabdominal operations].

PubMed

Voskanian, S É; Kyzlasov, P S

2011-01-01

The article describes the pathogenesis of adhesions formation after intraabdominal operations. Described predisposing factors leading of which is mechanical trauma, resulting from the use of surgical instruments, rough manipulations during surgery, damage to the mesothelium by dry gauze etc, which cause the adhesions. The pathogenesis of adhesions formation after intraabdominal surgery is presented in outline form, which described the changes occurring in the body starting with combination of predisposing factors and ending with the development of adhesions with blood vessels by 7-12 days after surgery. At the genetic level predisposition to adhesions formation and development of adhesive disease is treated as a manifestation of rapid acetylation phenotype, in which the intensity of fibrin formation exceeds normal rate of its catabolism. Thus, according to modem concepts, adhesive disease is a separate nosologic unit that dictates the necessity of its detailed study, development and introduction new universal methods of preventing the adhesions formation after intraabdominal operations.

Splenic infarction associated with sickle cell trait at low altitude.

PubMed

Seegars, Mary Beth; Brett, Allan S

2015-12-01

Sickle cell trait is widely known to be associated with splenic infarction at high altitudes. Although textbooks and reviews imply that this complication does not occur at low altitudes, we encountered such a case and identified several previous cases in the literature. An 18-year-old woman with sickle cell trait who resided near sea level presented with left upper quadrant abdominal pain and was found to have multiple splenic infarcts. She was otherwise well, with no comorbidities that would predispose to hypoxemia or vascular injury. A review of the literature revealed 12 previously published cases of low-altitude splenic infarction in patients with sickle trait; 7 of those patients had comorbidities that likely predisposed to splenic infarction. None. Spontaneous splenic infarction can occur in patients with sickle trait who live at low altitudes. It is unclear whether this complication is rare, or whether it is relatively common but under-recognized.

Factors Associated with HIV Viral Load in a Respondent Driven Sample in Los Angeles

PubMed Central

King, WD; Larkins, S; Hucks-Ortiz, C; Wang, J; Gorbach, P; Veniegas, R; Shoptaw, S

2008-01-01

This study used a modified version of the Behavioral Model for Vulnerable Populations to examine the predisposing, enabling, and need factors associated with detectable viral load (VL). HIV status was measured using saliva and confirmed by blood. Of 835 persons enrolled, 193 were HIV positive and provided VL counts. A multistage logistic regression demonstrated that the predisposing factors of homelessness and recent substance abuse, particularly methamphetamine abuse, had a negative association with VL. The negative association of homelessness was lessened with the introduction of enabling and need utilization factors in the model. In contrast, the negative association with recent substance abuse on VL was sustained in the final model. Provision of HIV care and medications attenuated the negative association of homelessness within this sample. Guided policy to address substance abuse among those who are HIV positive is needed to improve biological outcomes. PMID:18064555

What is dynapenia?

PubMed Central

Clark, Brian C.; Manini, Todd M.

2012-01-01

Dynapenia (pronounced dahy-nuh-pē-nē-a, Greek translation for poverty of strength, power, or force) is the age-associated loss of muscle strength that is not caused by neurologic or muscular diseases. Dynapenia predisposes older adults to an increased risk for functional limitations and mortality. For the past several decades, the literature has largely focused on muscle size as the primary cause of dynapenia; however, recent findings have clearly demonstrated that muscle size plays a relatively minor role. Conversely, subclinical deficits in the structure and function of the nervous system and/or impairments in the intrinsic force-generating properties of skeletal muscle are potential antecedents to dynapenia. This review highlights in the contributors to dynapenia and the etiology and risk factors that predispose individuals to dynapenia. In addition, we address the role of nutrition in the muscular and neurologic systems for the preservation of muscle strength throughout the life span. PMID:22469110

What is dynapenia?

PubMed

Clark, Brian C; Manini, Todd M

2012-05-01

Dynapenia (pronounced dahy-nuh-pē-nē-a, Greek translation for poverty of strength, power, or force) is the age-associated loss of muscle strength that is not caused by neurologic or muscular diseases. Dynapenia predisposes older adults to an increased risk for functional limitations and mortality. For the past several decades, the literature has largely focused on muscle size as the primary cause of dynapenia; however, recent findings have clearly demonstrated that muscle size plays a relatively minor role. Conversely, subclinical deficits in the structure and function of the nervous system and/or impairments in the intrinsic force-generating properties of skeletal muscle are potential antecedents to dynapenia. This review highlights in the contributors to dynapenia and the etiology and risk factors that predispose individuals to dynapenia. In addition, we address the role of nutrition in the muscular and neurologic systems for the preservation of muscle strength throughout the life span. Copyright © 2012 Elsevier Inc. All rights reserved.

Calcium oxalate crystal related kidney injury in a patient receiving Roux-en Y hepaticojejunostomy due to gall bladder cancer.

PubMed

Tsai, Jun-Li; Tsai, Shang-Feng

2017-03-29

Calcium oxalate nephropathy is rare in current practice. It was a common complication during jejunoileal bypass, but much less seen in modern gastric bypass surgery for morbid obesity. The major cause of it is enteric hyperoxaluria. We report on a patient here with acute kidney disease due to calcium oxalate nephropathy, rather than the conditions mentioned above. The male patient received a Roux-en Y hepaticojejunostomy and common bile duct drainage. In addition to enteric hyperoxaluria, chronic kidney disease related metabolic acidosis, chronic diarrhea related volume depletion, a high oxalate and low potassium diet, long term ascorbic acid intake and long term exposure to antibiotics, all predisposed him to having oxalate nephropathy. This is the first case with such conditions and we recommend that similarly diagnosed patients avoid all these predisposing factors, in order to avoid this rare disease and its undesired outcome.

He loves her, he loves her not: attachment style as a personality antecedent to men's ambivalent sexism.

PubMed

Hart, Joshua; Hung, Jacqueline A; Glick, Peter; Dinero, Rachel E

2012-11-01

The authors present an integrative account of how attachment insecurities relate to sexism. Two studies showed that attachment avoidance predisposes men to endorse hostile but to reject benevolent sexism (BS), whereas attachment anxiety predisposes men toward ambivalent (both hostile and benevolent) sexism. The authors also tested predicted mediators, finding that men's social dominance orientation (a competitive intergroup ideology) mediated the avoidance to hostile sexism link. In addition, romanticism (an idealized interpersonal ideology) mediated attachment insecurity to BS links: (a) Avoidant men tended to reject romanticism (i.e., were cynical about romance) and, in turn, were likely to reject BS, whereas (b) anxious men tended to endorse romanticism (i.e., were idealistic about romance) and, in turn, likely to endorse BS. The authors conclude that men's sexism stems in part from dispositional attachment working models, both directly and through the interpersonal and intergroup ideologies they generate.

Subclinical mastitis in dairy animals: incidence, economics, and predisposing factors.

PubMed

Sinha, Mukesh Kr; Thombare, N N; Mondal, Biswajit

2014-01-01

A study was conducted to assess the incidence and economics of subclinical form of bovine mastitis in Central Region of India. Daily milk records of 187 animals during three seasons were collected and subjected to analysis. The economic loss due to reduction in yield, clinical expenses, and additional resources used were quantified and aggregated. The losses due to mastitis in monetary terms were estimated to be INR1390 per lactation, among which around 49% was owing to loss of value from milk and 37% on account of veterinary expenses. Higher losses were observed in crossbred cows due to their high production potential that was affected during mastitis period. The cost of treating an animal was estimated to be INR509 which includes cost of medicine (31.10%) and services (5.47%). Inadequate sanitation, hygiene, and veterinary services were the main predisposing factors for incidence and spread of mastitis as perceived by the respondents.

A practical approach to the assessment of psychosocial and psychiatric comorbidity in the dermatology patient.

PubMed

Gupta, Madhulika A; Gupta, Aditya K

2013-01-01

It is well recognized that the clinical course of many dermatologic disorders is the result of a complex and sometimes reciprocal interaction between biological, psychiatric/psychological, and social factors that can have a predisposing, precipitating, and/or perpetuating role for the dermatologic disorder. Assessment of psychiatric and psychosocial comorbidity, which can be present in up to 30% of dermatology patients, is an important component of the overall clinical evaluation of the patient. This paper discusses a practical approach to the assessment of psychosocial and psychiatric factors, including suicide risk and parasuicidal behaviors in the dermatology patient. The approach further classifies these factors as predisposing, precipitating, and/or perpetuating, in order to aid the clinician with the possible secondary and tertiary prevention of some dermatologic disorders by management of their psychosocial and psychiatric comorbidity. Copyright © 2013 Elsevier Inc. All rights reserved.

Insight On Colorectal Carcinoma Infiltration by Studying Perilesional Extracellular Matrix

PubMed Central

Nebuloni, Manuela; Albarello, Luca; Andolfo, Annapaola; Magagnotti, Cinzia; Genovese, Luca; Locatelli, Irene; Tonon, Giovanni; Longhi, Erika; Zerbi, Pietro; Allevi, Raffaele; Podestà, Alessandro; Puricelli, Luca; Milani, Paolo; Soldarini, Armando; Salonia, Andrea; Alfano, Massimo

2016-01-01

The extracellular matrix (ECM) from perilesional and colorectal carcinoma (CRC), but not healthy colon, sustains proliferation and invasion of tumor cells. We investigated the biochemical and physical diversity of ECM in pair-wised comparisons of healthy, perilesional and CRC specimens. Progressive linearization and degree of organization of fibrils was observed from healthy to perilesional and CRC ECM, and was associated with a steady increase of stiffness and collagen crosslinking. In the perilesional ECM these modifications coincided with increased vascularization, whereas in the neoplastic ECM they were associated with altered modulation of matrisome proteins, increased content of hydroxylated lysine and lysyl oxidase. This study identifies the increased stiffness and crosslinking of the perilesional ECM predisposing an environment suitable for CRC invasion as a phenomenon associated with vascularization. The increased stiffness of colon areas may represent a new predictive marker of desmoplastic region predisposing to invasion, thus offering new potential application for monitoring adenoma with invasive potential. PMID:26940881

Posterior impingement syndromes of the ankle.

PubMed

Lee, Justin C; Calder, James D F; Healy, Jeremiah C

2008-06-01

Acute, or repetitive, compression of the posterior structures of the ankle may lead to posterior ankle impingement (PAI) syndrome, posteromedial ankle impingement (PoMI) syndrome, or Haglund's syndrome. The etiology of each of these conditions is quite different. Variations in posterior ankle osseous and soft tissue anatomy contribute to the etiology of PAI and Haglund's syndromes. The presence of an os trigonum or Stieda process is classically associated with PAI syndrome, whereas a prominent posterosuperior tubercle of the os calcis or Haglund's deformity is the osseous predisposing factor in Haglund's syndrome. PoMI has no defined predisposing anatomical variants but typically follows an inversion-supination injury of the ankle joint. This article discusses the biomechanics, clinical features, imaging, and management of each of these conditions. Magnetic resonance imaging (MRI) provides the optimal tool in posterior ankle assessment, and this review focuses on the MRI findings of each of the conditions just listed.

Effects of novelty on behavior in the adolescent and adult rat.

PubMed

Stansfield, Kirstie H; Kirstein, Cheryl L

2006-01-01

Adolescence is a time of high-risk behavior and increased exploration. This developmental period is marked by a greater probability of initiating drug use and is associated with an increased risk to develop addiction and dependency in adulthood. Human adolescents are predisposed towards an increased likelihood of risk taking behaviors (Zuckerman, 1986), including drug use or initiation. The purpose of the study was to examine differences in developmental risk taking behaviors. Adolescent and adult animals were exposed to a novel stimulus in a familiar environment to assess impulsive behaviors, novelty preference, and exploratory behaviors. Adolescent animals had greater novelty-induced locomotor activity, greater novelty preference, and showed higher approach and exploratory behaviors compared to adult animals. These data support the notion that adolescents may be predisposed toward sensation seeking and consequently, are more likely to engage in risk-taking behaviors, such as drug use initiation. Copyright 2005 Wiley Periodicals, Inc.

Assessing the Impact of Antidrug Advertising on Adolescent Drug Consumption: Results From a Behavioral Economic Model

PubMed Central

Block, Lauren G.; Morwitz, Vicki G.; Putsis, William P.; Sen, Subrata K.

2002-01-01

Objectives. This study examined whether adolescents’ recall of antidrug advertising is associated with a decreased probability of using illicit drugs and, given drug use, a reduced volume of use. Methods. A behavioral economic model of influences on drug consumption was developed with survey data from a nationally representative sample of adolescents to determine the incremental impact of antidrug advertising. Results. The findings provided evidence that recall of antidrug advertising was associated with a lower probability of marijuana and cocaine/crack use. Recall of such advertising was not associated with the decision of how much marijuana or cocaine/crack to use. Results suggest that individuals predisposed to try marijuana are also predisposed to try cocaine/crack. Conclusions. The present results provide support for the effectiveness of antidrug advertising programs. (Am J Public Health. 2002;92:1346–1351) PMID:12144995

The influence of small mammal burrowing activity on water storage at the Hanford Site

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

Landeen, D.S.

The amount and rate at which water may penetrate a protective barrier and come into contact with buried radioactive waste is a major concern. Because burrowing animals eventually will reside on the surface of any protective barrier, the effect these burrow systems may have on the loss or retention of water needs to be determined. The first section of this document summarizes the known literature relative to small mammals and the effects that burrowing activities have on water distribution, infiltration, and the overall impact of burrows on the ecosystem. Topics that are summarized include burrow air pressures, airflow, burrow humidity,more » microtopography, mounding, infiltration, climate, soil evaporation, and discussions of large pores relative to water distribution. The second section of this document provides the results of the study that was conducted at the Hanford Site to determine what effect small mammal burrows have on water storage. This Biointrusion task is identified in the Permanent Isolation Surface Barrier Development Plan in support of protective barriers. This particular animal intrusion task is one part of the overall animal intrusion task identified in Animal Intrusion Test Plan.« less

Microengineering of artificial capillaries

NASA Astrophysics Data System (ADS)

Moldovan, Nicanor I.

2002-11-01

Biocompatibility and functionality of implanted inorganic medical devices is limited by the local reaction of the organism, with a recently recognized contribution of nearby microvasculature. We explored the possibility to microengineer pre-embedded microvascular networks in the surface of inorganic devices. The implants would thus function as carriers of pre-assembled microvessels, ready to expand, and contribute to local angiogenesis. Based on our own studies on the role played by local microtopography in angiogenesis (the tunneling concept), we have shown the feasibility of endothelial cells cultivation in grooves created on the surface of the materials to be implanted, either polymeric or silicon. In order to develop this new technology, we devised an in situ approach to the study of the cellular behavior on micropatterned surfaces, by use of Laser Scanning Cytometry (LSC). In this report I will present our results regarding the LSC analysis of endothelial cells cultivated in grooves made on the surface of silicon wafers, and the consequences of this treatment on endothelial physiology. When comparing the growth of endothelial cells on line patterned and non-patterned areas, in terms of several morphological parameters of cell nuclei, our data support the conclusion that lateral confinement of endothelial cells induces a quiescent state, possibly by inhibiting their ability to proliferate.

Estimating eroded soil and predicting further erosion in Daisetsuzan National Park in Hokkaido, Japan

NASA Astrophysics Data System (ADS)

Kobayashi, Yusuke; Watanabe, Teiji

2017-04-01

This study has three objectives: (1) to estimate changes of the eroded volume of mountain trails from 2014 to 2016 by making DSMs, (2) to understand a relationship between the trail erosion and micro-topography, and (3) to predict the volume of soil that can be eroded in future. Trail erosion has been investigated near Mt. Hokkai-dake in Daisetzuzan National Park, Hokkaido, northern Japan, with a drone (UAV) from 2014 to 2016. Seven segments with the soil erosion from starting sites to ending sites were selected to make DSMs and Orthophotographs by Agisoft, which is one of the Structure from Motion (SfM) software. Then, at fourteen points in each of the seven segments were selected to estimate the volume of soil that can be eroded in the future by PANDA2, a soil compaction penetrometer. The eroded volume in the segment with the largest eroded value attained 274.67 m3 for the two-year period although extremely heavy rain hit this area in the 2016 summer. The result obtained by PANDA2 shows that soil more than 100 cm in depth will be potentially eroded at four points in three years to one hundred years.

Investigating the limits of filopodial sensing: a brief report using SEM to image the interaction between 10 nm high nano-topography and fibroblast filopodia.

PubMed

Dalby, M J; Riehle, M O; Johnstone, H; Affrossman, S; Curtis, A S G

2004-01-01

Having the ability to control cell behaviour would be of great advantage in tissue engineering. One method of gaining control over cell adhesion, proliferation, guidance and differentiation is use of topography. Whilst it has be known for some time that cells can be guided by micro-topography, it is only recently becoming clear that cells will respond strongly to nano-scale topography. The fact that cells will take cues from their micro- and nano-environment suggests that the cells are in some way 'spatially aware'. It is likely that cells probe the shape of their surroundings using filopodia, and that this initial filopodia/topography interaction may be critical to down-stream cell reactions to biomaterials, or indeed, the extracellular matrix. One intriguing question is how small a feature can cells sense? In order to investigate the limits of cell sensing, high-resolution scanning electron microscopy has been used to simultaneously view cell filopodia and 10 nm high nano-islands. Fluorescence microscopy has also been used to look at adhesion formation. The results showed distinct filopodial/nano-island interaction and changes in adhesion morphology.

Raman studies of the interactions of fibrous carbon nanomaterials with albumin

NASA Astrophysics Data System (ADS)

Wesełucha-Birczyńska, Aleksandra; Morajka, Krzysztof; Stodolak-Zych, Ewa; Długoń, Elżbieta; Dużyja, Maria; Lis, Tomasz; Gubernat, Maciej; Ziąbka, Magdalena; Błażewicz, Marta

2018-05-01

Adsorption or immobilization of proteins on synthetic surfaces is a key issue in the context of the biocompatibility of implant materials, especially those intended for the needs of cardiac surgery but also for the construction of biosensors or nanomaterials used as drug carriers. The subject of research was the analysis of Raman spectra of two types of fibrous carbon nanomaterials, of great potential for biomedical applications, incubated with human serum albumin (HSA). The first nanomaterial has been created on the layer of MWCNTs deposited by electrophoretic method (EPD) and then covered by thin film of pyrolytic carbon introduced by chemical vapor deposition process (CVD). The second material was formed from carbonized nanofibers prepared via electrospinning (ESCNFs) of polyacrylonitrile (PAN) precursor and then covered with pyrolytic carbon (CVD). The G-band blue-shift towards the position of about 1600 cm-1, observed for both studied surfaces, clearly indicates the albumin (HSA) adhesion to the surface. The G and G' (2D) peak shift was employed to assess the stress build up on the carbon nanomaterials. The surface nano- and micro-topography as well as the method of ordering the carbon nanomaterial has a significant influence on the mode of surface-protein interaction.

Landscape trajectories during the Lateglacial and the Holocene in the Loir River Valley (France) : the contribution of Geoarchaeology

NASA Astrophysics Data System (ADS)

Piana, Juliene

2015-04-01

A multidisciplinary research has been initiated in the Loir River valley where investigations revealed high-potential fluvial records and landforms for environmental and socio-environmental reconstructions. Investigations provide the opportunity to reconstruct landscape trajectories between climate, environmental and societal changes during the last 16000 years, using geoarchaeological and archaeogeographical approaches: sedimentology, soil micromorphology, geochemistry, archaeology, geomatics, geochronology (AGES Program: Ancient Geomorphological EvolutionS of Loire Basin hydrosystem). In the sector of Vaas (Sarthe, France) the research on the Lateglacial and the Holocene sedimentary sequences from the alluvial plain leads to a general overview of the valley evolution from the end of the Weichselian Upper Pleniglacial to the Present. Joined to archaeological (Protohistoric and Antic sites) and historical data (engineering archives, 18th century cadastral registers) this research highlights the importance of anthropogenic and geomorphological heritages in the current fluvial landscape (microtopography, wetlands, archaeological remains, land use). This knowledge constitutes a basis for skills transfer to planners and managers, in sustainable management of hydrological resources (reducing the vulnerability to flooding and low flows), preservation of biodiversity (wetlands protection) and valorization of landscapes (cultural tourism development).

Urokinase Receptor Counteracts Vascular Smooth Muscle Cell Functional Changes Induced by Surface Topography

PubMed Central

Kiyan, Yulia; Kurselis, Kestutis; Kiyan, Roman; Haller, Hermann; Chichkov, Boris N.; Dumler, Inna

2013-01-01

Current treatments for human coronary artery disease necessitate the development of the next generations of vascular bioimplants. Recent reports provide evidence that controlling cell orientation and morphology through topographical patterning might be beneficial for bioimplants and tissue engineering scaffolds. However, a concise understanding of cellular events underlying cell-biomaterial interaction remains missing. In this study, applying methods of laser material processing, we aimed to obtain useful markers to guide in the choice of better vascular biomaterials. Our data show that topographically treated human primary vascular smooth muscle cells (VSMC) have a distinct differentiation profile. In particular, cultivation of VSMC on the microgrooved biocompatible polymer E-shell induces VSMC modulation from synthetic to contractile phenotype and directs formation and maintaining of cell-cell communication and adhesion structures. We show that the urokinase receptor (uPAR) interferes with VSMC behavior on microstructured surfaces and serves as a critical regulator of VSMC functional fate. Our findings suggest that microtopography of the E-shell polymer could be important in determining VSMC phenotype and cytoskeleton organization. They further suggest uPAR as a useful target in the development of predictive models for clinical VSMC phenotyping on functional advanced biomaterials. PMID:23843899

Tundra landform and vegetation productivity trend maps for the Arctic Coastal Plain of northern Alaska

PubMed Central

Lara, Mark J.; Nitze, Ingmar; Grosse, Guido; McGuire, A. David

2018-01-01

Arctic tundra landscapes are composed of a complex mosaic of patterned ground features, varying in soil moisture, vegetation composition, and surface hydrology over small spatial scales (10–100 m). The importance of microtopography and associated geomorphic landforms in influencing ecosystem structure and function is well founded, however, spatial data products describing local to regional scale distribution of patterned ground or polygonal tundra geomorphology are largely unavailable. Thus, our understanding of local impacts on regional scale processes (e.g., carbon dynamics) may be limited. We produced two key spatiotemporal datasets spanning the Arctic Coastal Plain of northern Alaska (~60,000 km2) to evaluate climate-geomorphological controls on arctic tundra productivity change, using (1) a novel 30 m classification of polygonal tundra geomorphology and (2) decadal-trends in surface greenness using the Landsat archive (1999–2014). These datasets can be easily integrated and adapted in an array of local to regional applications such as (1) upscaling plot-level measurements (e.g., carbon/energy fluxes), (2) mapping of soils, vegetation, or permafrost, and/or (3) initializing ecosystem biogeochemistry, hydrology, and/or habitat modeling. PMID:29633984

Do hummocks provide a physiological advantage to even the most flood tolerant of tidal freshwater trees?

USGS Publications Warehouse

Duberstein, Jamie A.; Krauss, Ken W.; Conner, William H.; Bridges, William C.; Shelburne, Victor B.

2013-01-01

Hummock and hollow microtopography is pervasive in tidal freshwater swamps. Many tree species grow atop hummocks significantly more than in hollows, leading to the hypothesis that hummocks provide preferred locations for maximizing physiological proficiency of inhabiting trees that experience repeated flooding. We used thermal dissipation probes to measure the ecophysiological proficiency of a very flood-tolerant tree, Taxodium distichum, as manifested through in-situ changes in sapflow (a proxy for transpiration) in 11 trees on hummocks and 11 trees in hollows. Overall, sapflow increased significantly by 3.3 g H2O m−2 s−1 (11 %) in trees on both hummocks and hollows during flooding, contrary to our expectations. We found no significant differences in sapflow rates between T. distichum trees positioned on hummocks versus hollows in relation to discrete flood events. Coincidentally, hummock elevations were equivalent to the flood depths that promoted greatest physiological proficiency in T. distichum, suggesting a physiological role for the maintenance of hummock height in tidal swamps. While we reject our original hypotheses that flooding and positioning in hollows will reduce sapflow in T. distichum, this research reveals a potentially important feedback between hummock height, flood depth, and maximum tree physiological response.

Mesh infrastructure for coupled multiprocess geophysical simulations

DOE PAGES

Garimella, Rao V.; Perkins, William A.; Buksas, Mike W.; ...

2014-01-01

We have developed a sophisticated mesh infrastructure capability to support large scale multiphysics simulations such as subsurface flow and reactive contaminant transport at storage sites as well as the analysis of the effects of a warming climate on the terrestrial arctic. These simulations involve a wide range of coupled processes including overland flow, subsurface flow, freezing and thawing of ice rich soil, accumulation, redistribution and melting of snow, biogeochemical processes involving plant matter and finally, microtopography evolution due to melting and degradation of ice wedges below the surface. In addition to supporting the usual topological and geometric queries about themore » mesh, the mesh infrastructure adds capabilities such as identifying columnar structures in the mesh, enabling deforming of the mesh subject to constraints and enabling the simultaneous use of meshes of different dimensionality for subsurface and surface processes. The generic mesh interface is capable of using three different open source mesh frameworks (MSTK, MOAB and STKmesh) under the hood allowing the developers to directly compare them and choose one that is best suited for the application's needs. We demonstrate the results of some simulations using these capabilities as well as present a comparison of the performance of the different mesh frameworks.« less

Tundra landform and vegetation productivity trend maps for the Arctic Coastal Plain of northern Alaska

USGS Publications Warehouse

Lara, Mark J.; Nitze, Ingmar; Grosse, Guido; McGuire, A. David

2018-01-01

Arctic tundra landscapes are composed of a complex mosaic of patterned ground features, varying in soil moisture, vegetation composition, and surface hydrology over small spatial scales (10–100 m). The importance of microtopography and associated geomorphic landforms in influencing ecosystem structure and function is well founded, however, spatial data products describing local to regional scale distribution of patterned ground or polygonal tundra geomorphology are largely unavailable. Thus, our understanding of local impacts on regional scale processes (e.g., carbon dynamics) may be limited. We produced two key spatiotemporal datasets spanning the Arctic Coastal Plain of northern Alaska (~60,000 km2) to evaluate climate-geomorphological controls on arctic tundra productivity change, using (1) a novel 30 m classification of polygonal tundra geomorphology and (2) decadal-trends in surface greenness using the Landsat archive (1999–2014). These datasets can be easily integrated and adapted in an array of local to regional applications such as (1) upscaling plot-level measurements (e.g., carbon/energy fluxes), (2) mapping of soils, vegetation, or permafrost, and/or (3) initializing ecosystem biogeochemistry, hydrology, and/or habitat modeling.

Effect of enzymatic degradation of chitosan in polyhydroxybutyrate/chitosan/calcium phosphate composites on in vitro osteoblast response.

PubMed

Giretova, Maria; Medvecky, Lubomir; Stulajterova, Radoslava; Sopcak, Tibor; Briancin, Jaroslav; Tatarkova, Monika

2016-12-01

Polyhydroxybutyrate/chitosan/calcium phosphate composites are interesting biomaterials for utilization in regenerative medicine and they may by applied in reconstruction of deeper subchondral defects. Insufficient informations were found in recent papers about the influence of lysozyme degradation of chitosan in calcium phosphate/chitosan based composites on in vitro cytotoxicity and proliferation activity of osteoblasts. The effect of enzymatic chitosan degradation on osteoblasts proliferation was studied on composite films in which the porosity of origin 3D scaffolds was eliminated and the surface texture was modified. The significantly enhanced proliferation activity with faster population growth of osteoblasts were found on enzymatically degraded biopolymer composite films with α-tricalcium phosphate and nanohydroxyapatite. No cytotoxicity of composite films prepared from lysozyme degraded scaffolds containing a large fraction of low molecular weight chitosans (LMWC), was revealed after 10 days of cultivation. Contrary to above in the higher cytotoxicity origin untreated nanohydroxyapatite films and porous composite scaffolds. The results showed that the synergistic effect of surface distribution, morphology of nanohydroxyapatite particles, microtopography and the presence of LMWC due to chitosan degradation in composite films were responsible for compensation of the cytotoxicity of nanohydroxyapatite composite films or porous composite scaffolds.

Investigation of the Geochemical Preservation of ca. 3.0 Ga Permineralized and Encapsulated Microfossils by Nanoscale Secondary Ion Mass Spectrometry

NASA Astrophysics Data System (ADS)

Delarue, Frédéric; Robert, François; Sugitani, Kenichiro; Tartèse, Romain; Duhamel, Rémi; Derenne, Sylvie

2017-12-01

Observations of Archean organic-walled microfossils suggest that their fossilization took place through both encapsulation and permineralization. In this study, we investigated microfossils from the ca. 3.0 Ga Farrel Quartzite (Pilbara, Western Australia) using transmitted light microscopy, scanning electron microscopy, Raman microspectrometry, and nanoscale secondary ion mass spectrometry (NanoSIMS) ion microprobe analyses. In contrast to previous studies, we demonstrated that permineralized microfossils were not characterized by the micrometric spatial relationships between Si and C-N as observed in thin sections. Permineralized microfossils are composed of carbonaceous globules that did not survive the acid treatment, whereas encapsulated microfossils were characterized due to their resistance to the acid maceration procedure. We also investigated the microscale relationship between the 12C14N- and 12C2- ion emission as a proxy of the N/C atomic ratio in both permineralized and encapsulated microfossils. After considering any potential matrix and microtopography effects, we demonstrate that the encapsulated microfossils exhibit the highest level of geochemical preservation. This finding shows that the chemical heterogeneity of the microfossils, observed at a spatial resolution of a few hundreds of micrometers, can be related to fossilization processes.

Are prostatic calculi independent predictive factors of lower urinary tract symptoms?

PubMed

Park, Sung-Woo; Nam, Jong-Kil; Lee, Sang-Don; Chung, Moon-Kee

2010-03-01

We determined the correlation between prostatic calculi and lower urinary tract symptoms (LUTS), as well as the predisposing factors of prostatic calculi. Of the 1 527 patients who presented at our clinic for LUTS, 802 underwent complete evaluations, including transrectal ultrasonography, voided bladder-3 specimen and international prostatic symptoms score (IPSS). A total of 335 patients with prostatic calculi and 467 patients without prostatic calculi were divided into calculi and no calculi groups, respectively. Predictive factors of severe LUTS and prostatic calculi were determined using uni/multivariate analysis. The overall IPSS score was 15.7 +/- 9.2 and 14.1 +/- 9.2 in the calculi and no calculi group, respectively (P = 0.013). The maximum flow rate was 12.1 +/- 6.9 and 14.2 +/- 8.2 mL s(-1) in the calculi and no calculi group, respectively (P = 0.003). On univariate analysis for predicting factors of severe LUTS, differences on age (P = 0.042), prostatic calculi (P = 0.048) and prostatitis (P = 0.018) were statistically significant. However, on multivariate analysis, no factor was significant. On multivariate analysis for predisposing factors of prostatic calculi, differences on age (P < 0.001) and prostate volume (P = 0.001) were significant. To our knowledge, patients who have prostatic calculi complain of more severe LUTS. However, prostatic calculi are not an independent predictive factor of severe LUTS. Therefore, men with prostatic calculi have more severe LUTS not only because of prostatic calculi but also because of age and other factors. In addition, old age and large prostate volume are independent predisposing factors for prostatic calculi.

Clinical features and outcome of cerebral abscess in congenital heart disease.

PubMed

Mehnaz, Atiq; Syed, Ahmed Umair; Saleem, Allana Salman; Khalid, Chishti N

2006-01-01

Cerebral abscess is a serious life threatening complication of several diseases. The objective of this study was to look at the clinical profile, microbiology and outcome of children with cerebral abscess having an underlying congenital heart disease as compared to other predisposing conditions. Thirty children aged less than 15 years were reviewed. There were 15 males and 15 females. The mean age of presentation was 5.6 +/- 4.4 years. The duration of illness at the time of admission was 17.6 +/- 24.6 days. Typically patients presented with fever, vomiting, headache and seizures. The predisposing conditions found were cyanotic congenital heart disease in 11 (37%) of children, meningitis in 6 (20%), septicemia in 7 (23%) and no underlying cause was found in 5 (17%) children. The most common microbe in children with cyanotic congenital heart disease was of the Streptococcus milleri group (52%). Computerized tomography confirmed the diagnosis and the most common location of the abscess was the parietal lobe of the cerebral hemisphere. All abscesses were large, more than 2 cm in diameter and were aspirated surgically. Excision was performed in 6 children. Five children expired, one due to a intracranial bleeding and the others due to severe cerebral edema and tentorial herniation. Complications were seen in 20 children and 16 had sequelae, hemiparesis in 11 and seizure disorder in 5. Brain abscess is a serious infection with poor outcome if diagnosed late. Delayed surgical drainage has high morbidity and mortality. The threshold for diagnosis should be low particularly in children with a predisposing condition like cyanotic congenital heart disease.

Pathogenesis of rhegmatogenous retinal detachment: predisposing anatomy and cell biology.

PubMed

Mitry, Danny; Fleck, Brian W; Wright, Alan F; Campbell, Harry; Charteris, David G

2010-01-01

The pathogenesis of rhegmatogenous retinal detachment is complex, and our knowledge of the exact mechanism of vitreoretinal attachment and detachment remains incomplete. We performed a Medline, Ovid, and EMBASE search using search words rhegmatogenous, retinal detachment, vitreous, and retinal adhesion. All appropriate articles were reviewed, and the evidence was compiled. Cortical vitreous contains fibrillar collagens type II, V/XI, and IX. The inner limiting membrane of the retina contains collagens type I, IV, VI, and XVIII as well as numerous other glycoproteins and potential adhesion molecules. The distribution and age-related changes in the structure of these molecules play an important role in the formation of a retinal break, which may compromise and disrupt the normal mechanisms of neurosensory retinal adhesion. Rhegmatogenous retinal detachment development is intimately related to changes in the fibrillar structure of the aging vitreous culminating in posterior vitreous detachment with regions of persistent and tangential vitreoretinal traction predisposing to retinal tear formation. A complex interplay of factors such as weakening of vitreoretinal adhesion, posterior migration of the vitreous base, and molecular changes at the vitreoretinal interface are important in predisposing to focal areas of vitreoretinal traction precipitating rhegmatogenous retinal detachment. Once formed, the passage of liquefied vitreous through a retinal break may overwhelm normal neurosensory-retinal pigment epithelium adhesion perpetuating and extending detachment and causing visual loss. To understand the molecular events underlying rhegmatogenous retinal detachment so that new therapies can be developed, it is important to appreciate the structural organization of the vitreous, the biology underlying vitreous liquefaction and posterior vitreous detachment, and the mechanisms of vitreoretinal attachment and detachment.

The Mycotoxin Deoxynivalenol Predisposes for the Development of Clostridium perfringens-Induced Necrotic Enteritis in Broiler Chickens

PubMed Central

Antonissen, Gunther; Ducatelle, Richard; Haesebrouck, Freddy; Timbermont, Leen; Verlinden, Marc; Janssens, Geert Paul Jules; Eeckhaut, Venessa; Eeckhout, Mia; De Saeger, Sarah; Hessenberger, Sabine; Martel, An; Croubels, Siska

2014-01-01

Both mycotoxin contamination of feed and Clostridium perfringens-induced necrotic enteritis have an increasing global economic impact on poultry production. Especially the Fusarium mycotoxin deoxynivalenol (DON) is a common feed contaminant. This study aimed at examining the predisposing effect of DON on the development of necrotic enteritis in broiler chickens. An experimental Clostridium perfringens infection study revealed that DON, at a contamination level of 3,000 to 4,000 µg/kg feed, increased the percentage of birds with subclinical necrotic enteritis from 20±2.6% to 47±3.0% (P<0.001). DON significantly reduced the transepithelial electrical resistance in duodenal segments (P<0.001) and decreased duodenal villus height (P = 0.014) indicating intestinal barrier disruption and intestinal epithelial damage, respectively. This may lead to an increased permeability of the intestinal epithelium and decreased absorption of dietary proteins. Protein analysis of duodenal content indeed showed that DON contamination resulted in a significant increase in total protein concentration (P = 0.023). Furthermore, DON had no effect on in vitro growth, alpha toxin production and netB toxin transcription of Clostridium perfringens. In conclusion, feed contamination with DON at concentrations below the European maximum guidance level of 5,000 µg/kg feed, is a predisposing factor for the development of necrotic enteritis in broilers. These results are associated with a negative effect of DON on the intestinal barrier function and increased intestinal protein availability, which may stimulate growth and toxin production of Clostridium perfringens. PMID:25268498

Environmental disruption of circadian rhythm predisposes mice to osteoarthritis-like changes in knee joint.

PubMed

Kc, Ranjan; Li, Xin; Voigt, Robin M; Ellman, Michael B; Summa, Keith C; Vitaterna, Martha Hotz; Keshavarizian, Ali; Turek, Fred W; Meng, Qing-Jun; Stein, Gary S; van Wijnen, Andre J; Chen, Di; Forsyth, Christopher B; Im, Hee-Jeong

2015-09-01

Circadian rhythm dysfunction is linked to many diseases, yet pathophysiological roles in articular cartilage homeostasis and degenerative joint disease including osteoarthritis (OA) remains to be investigated in vivo. Here, we tested whether environmental or genetic disruption of circadian homeostasis predisposes to OA-like pathological changes. Male mice were examined for circadian locomotor activity upon changes in the light:dark (LD) cycle or genetic disruption of circadian rhythms. Wild-type (WT) mice were maintained on a constant 12 h:12 h LD cycle (12:12 LD) or exposed to weekly 12 h phase shifts. Alternatively, male circadian mutant mice (Clock(Δ19) or Csnk1e(tau) mutants) were compared with age-matched WT littermates that were maintained on a constant 12:12 LD cycle. Disruption of circadian rhythms promoted osteoarthritic changes by suppressing proteoglycan accumulation, upregulating matrix-degrading enzymes and downregulating anabolic mediators in the mouse knee joint. Mechanistically, these effects involved activation of the PKCδ-ERK-RUNX2/NFκB and β-catenin signaling pathways, stimulation of MMP-13 and ADAMTS-5, as well as suppression of the anabolic mediators SOX9 and TIMP-3 in articular chondrocytes of phase-shifted mice. Genetic disruption of circadian homeostasis does not predispose to OA-like pathological changes in joints. Our results, for the first time, provide compelling in vivo evidence that environmental disruption of circadian rhythms is a risk factor for the development of OA-like pathological changes in the mouse knee joint. © 2015 Wiley Periodicals, Inc.

Anaerobic infections in surgical wards: a two year study

PubMed Central

Ananth-Shenoy, Padmaja; Vishwanath, Shashidhar; Targain, Ryumzook; Shetty, Seema; Sunil-Rodrigues, Gabriel; Mukhopadhyay, Chiranjay; Chawla, Kiran

2016-01-01

Background and Objectives: Anaerobic bacteria are recognized as important pathogens in surgical infections. However, they are the most overlooked microorganisms by the clinic and the laboratory because of the tedious culture techniques with longer turn-around times. The study was aimed to analyze the frequency of anaerobic bacterial surgical infections and their predisposing factors. Materials and Methods: A retrospective study was conducted over a period of two years including patients with surgical infections. The specimens were processed by Gram staining, aerobic and anaerobic culture. The anaerobic bacteria were isolated using standard procedures. The predisposing factors and clinical presentation were studied in these patients. Results: A total of 261 specimens were received from patients with diverse infections from surgical wards. Ninety-one anaerobes were isolated from 64 (24.5%) surgical patients with a predominance of Gram-negative bacilli (37.4%). Anaerobic bacteria as monomicrobial isolates were seen in 21.9% isolates. Anaerobic bacterial isolation along with aerobic bacteria was seen in 71.9% of patients and polymicrobial anaerobic growth was detected in 6.3% of patients. Diabetes mellitus (28, 43.8%) was found to be the most frequent predisposing factor. Bacteroides fragilis group (20.9%) were the most frequent anaerobic Gram-negative bacilli followed by Prevotella spp. (12.1%). Peptostreptococcus anaerobius was the predominant anaerobic cocci isolated (14.3%). Necrotizing fascitis (34.4%) was the most common clinical presentation with anaerobic etiology followed by deep seated abscesses (23.4%). Conclusion: Anaerobic bacteria were isolated from a significant proportion of surgical infections. To avoid therapeutic failures, anaerobic bacteria in surgical infections need to be recognized by surgeons and laboratorians. PMID:27928485

Increased placental trophoblast inclusions in placenta accreta.

PubMed

Adler, E; Madankumar, R; Rosner, M; Reznik, S E

2014-12-01

Trophoblast inclusions (TIs) are often found in placentas of genetically abnormal gestations. Although best documented in placentas from molar pregnancies and chromosomal aneuploidy, TIs are also associated with more subtle genetic abnormalities, and possibly autism. Less than 3% of non-aneuploid, non-accreta placentas have TIs. We hypothesize that placental genetics may play a role in the development of placenta accreta and aim to study TIs as a potential surrogate indicator of abnormal placental genetics. Forty cases of placenta accreta in the third trimester were identified in a search of the medical records at one institution. Forty two third trimester control placentas were identified by a review of consecutively received single gestation placentas with no known genetic abnormalities and no diagnosis of placenta accreta. Forty percent of cases with placenta accreta demonstrated TIs compared to 2.4% of controls. More invasive placenta accretas (increta and percreta) were more likely to demonstrate TIs than accreta (47% versus 20%). Prior cesarean delivery was more likely in accreta patients than controls (67% versus 9.5%). Placenta accreta is thought to be the result of damage to the endometrium predisposing to abnormal decidualization and invasive trophoblast growth into the myometrium. However, the etiology of accreta is incompletely understood with accreta frequently occurring in women without predisposing factors and failing to occur in predisposed patients. This study has shown that TIs are present at increased rates in cases of PA. Further studies are needed to discern what underlying pathogenic mechanisms are in common between abnormal placentation and the formation of TIs. Published by Elsevier Ltd.

Risk markers for both chronic fatigue and irritable bowel syndromes: a prospective case-control study in primary care.

PubMed

Hamilton, W T; Gallagher, A M; Thomas, J M; White, P D

2009-11-01

Fatigue syndromes and irritable bowel syndrome (IBS) often occur together. Explanations include being different manifestations of the same condition and simply sharing some symptoms. A matched case-control study in UK primary care, using data collected prospectively in the General Practice Research Database (GPRD). The main outcome measures were: health-care utilization, specific symptoms and diagnoses. Risk markers were divided into distant (from 3 years to 1 year before diagnosis) and recent (1 year before diagnosis). A total of 4388 patients with any fatigue syndrome were matched to two groups of patients: those attending for IBS and those attending for another reason. Infections were specific risk markers for both syndromes, with viral infections being a risk marker for a fatigue syndrome [odds ratios (ORs) 2.3-6.3], with a higher risk closer to onset, and gastroenteritis a risk for IBS (OR 1.47, compared to a fatigue syndrome). Chronic fatigue syndrome (CFS) shared more distant risk markers with IBS than other fatigue syndromes, particularly other symptom-based disorders (OR 3.8) and depressive disorders (OR 2.3), but depressive disorders were a greater risk for CFS than IBS (OR 2.4). Viral infections were more of a recent risk marker for CFS compared to IBS (OR 2.8), with gastroenteritis a greater risk for IBS (OR 2.4). Both fatigue and irritable bowel syndromes share predisposing risk markers, but triggering risk markers differ. Fatigue syndromes are heterogeneous, with CFS sharing predisposing risks with IBS, suggesting a common predisposing pathophysiology.

Explaining use of food parenting practices: the importance of predisposing factors and parental cognitions.

PubMed

Gevers, Dorus Wm; van Assema, Patricia; de Vries, Nanne K; Kremers, Stef Pj

2017-09-01

The high energy intake from energy-dense foods among children in developed countries is undesirable. Improving food parenting practices has the potential to lower snack intakes among children. To inform the development of interventions, we aimed to predict food parenting practice patterns around snacking (i.e. 'high covert control and rewarding', 'low covert control and non-rewarding', 'high involvement and supportive' and 'low involvement and indulgent'). A cross-sectional survey was conducted. To predict the patterns of food parenting practices, multinomial logistic regression analyses were run with 888 parents. Predictors included predisposing factors (i.e. parents' and children's demographics and BMI, parents' personality, general parenting, and parenting practices used by their own parents) and parents' cognitions (i.e. perceived behaviour of other parents, subjective norms, attitudes, self-efficacy and outcome expectations). The Netherlands (October-November 2014). Dutch parents of children aged 4-12 years old. After backward elimination, nineteen factors had a statistically significant contribution to the model (Nagelkerke R 2=0·63). Overall, self-efficacy and outcome expectations were among the strongest explanatory factors. Considering the predisposing factors only, the general parenting factor nurturance most strongly predicted the food parenting clusters. Nurturance particularly distinguished highly involved parents from parents employing a pattern of low involvement. Parental cognitions and nurturance are important factors to explain the use of food parenting practices around snacking. The results suggest that intervention developers should attempt to increase self-efficacy and educate parents about what constitute effective and ineffective parenting practices. Promoting nurturance might be a prerequisite to achieve prolonged change.

Barriers and enablers to proper diabetic foot care amongst community dwellers in an Asian population: a qualitative study

PubMed Central

Cuttilan, Amit Nirmal; Pearce, Christopher J.

2017-01-01

Background Diabetic foot complications are common within Asian populations. They arise due to poor diabetic control and foot care. In this study, we aimed to identify the causes for proper and improper diabetic foot care. Methods A qualitative study consisting of key informant interviews with 17 healthcare professionals, including doctors and various allied health workers, was conducted. Participants included had at least five years of caring for diabetic foot patients either in public institutions or private clinics. Data collected was analyzed via thematic analysis. Results Diabetic patients were generally observed to have a mixture of proper and improper information and beliefs which eventually resulted in the extent of proper foot care. Factors which influenced the extent of proper and improper state of information and beliefs were classified into predisposing and precipitating factors. Predisposing factors were further categorised into modifiable factors (e.g., education level, socioeconomic status, social support) and non-modifiable factors (e.g., age, presence and severity of co-morbidities restricting ability to selfcare, past experiences). Precipitating factors were categorized into patient factors (e.g., degree of reception of information, presence of psychological barriers), provider factors (presence and degree of multi-disciplinary approach to care, presence of administrative inconveniences) and disease factors (presence of diabetic sensory neuropathy, complexity of disease process). Conclusions The extent of proper foot care amongst diabetic patients is influenced by numerous predisposing and precipitating factors. Further studies can look at further development of the described structure as well as quantitatively defining the various components and factors which make up the described system. PMID:28706922

Assessment of HIV testing among young methamphetamine users in Muse, Northern Shan State, Myanmar

PubMed Central

2014-01-01

Background Methamphetamine (MA) use has a strong correlation with risky sexual behaviors, and thus may be triggering the growing HIV epidemic in Myanmar. Although methamphetamine use is a serious public health concern, only a few studies have examined HIV testing among young drug users. This study aimed to examine how predisposing, enabling and need factors affect HIV testing among young MA users. Methods A cross-sectional study was conducted from January to March 2013 in Muse city in the Northern Shan State of Myanmar. Using a respondent-driven sampling method, 776 MA users aged 18-24 years were recruited. The main outcome of interest was whether participants had ever been tested for HIV. Descriptive statistics and multivariate logistic regression were applied in this study. Results Approximately 14.7% of young MA users had ever been tested for HIV. Significant positive predictors of HIV testing included predisposing factors such as being a female MA user, having had higher education, and currently living with one’s spouse/sexual partner. Significant enabling factors included being employed and having ever visited NGO clinics or met NGO workers. Significant need factors were having ever been diagnosed with an STI and having ever wanted to receive help to stop drug use. Conclusions Predisposing, enabling and need factors were significant contributors affecting uptake of HIV testing among young MA users. Integrating HIV testing into STI treatment programs, alongside general expansion of HIV testing services may be effective in increasing HIV testing uptake among young MA users. PMID:25042697

Factors predisposing nursing home resident to inappropriate transfer to emergency department. The FINE study protocol.

PubMed

Perrin, Amélie; Tavassoli, Neda; Mathieu, Céline; Hermabessière, Sophie; Houles, Mathieu; McCambridge, Cécile; Magre, Elodie; Fernandez, Sophie; Caquelard, Anne; Charpentier, Sandrine; Lauque, Dominique; Azema, Olivier; Bismuth, Serge; Chicoulaa, Bruno; Oustric, Stéphane; Costa, Nadège; Molinier, Laurent; Vellas, Bruno; Bérard, Emilie; Rolland, Yves

2017-09-01

Each year, around one out of two nursing home (NH) residents are hospitalized in France, and about half to the emergency department (ED). These transfers are frequently inappropriate. This paper describes the protocol of the FINE study. The first aim of this study is to identify the factors associated with inappropriate transfers to ED. FINE is a case-control observational study. Sixteen hospitals participate. Inclusion period lasts 7 days per season in each center for a total period of inclusion of one year. All the NH residents admitted in ED during these periods are included. Data are collected in 4 times: before transfer in the NH, at the ED, in hospital wards in case of patient's hospitalization and at the patient's return to NH. The appropriateness of ED transfers (i.e. case versus control NH residents) is determined by a multidisciplinary team of experts. Our primary objective is to determine the factors predisposing NH residents to inappropriate transfer to ED. Our secondary objectives are to assess the cost of the transfers to ED; study the evolution of NH residents' functional status and the psychotropic and inappropriate drugs prescription between before and after the transfer; calculate the prevalence of potentially avoidable transfers to ED; and identify the factors predisposing NH residents to potentially avoidable transfer to ED. A better understanding of the determinant factors of inappropriate transfers to ED of NH residents may lead to proposals of recommendations of better practice in NH and would allow implementing quality improvement programs in the health organization.

Streptococcus gallolyticus meningitis in adults: report of five cases and review of the literature.

PubMed

van Samkar, A; Brouwer, M C; Pannekoek, Y; van der Ende, A; van de Beek, D

2015-12-01

We describe the incidence and patient characteristics of Streptococcus gallolyticus meningitis. We identified S. gallolyticus meningitis in a nationwide cohort of patients with community-acquired bacterial meningitis, and performed a systematic review and meta-analysis of all reported adult cases in the literature. Five cases were identified (0.3%) in a cohort of 1561 episodes of bacterial meningitis. In one patient, bowel disease (colon polyps) was identified as a predisposing condition for S. gallolyticus infection, whereas no patients were diagnosed with endocarditis. In a combined analysis of our patients and 37 reported in the literature, we found that the median age was 59 years. Predisposing factors were present in 21 of 42 patients (50%), and mainly consisted of immunosuppressive therapy (seven patients), cancer (four patients), and alcoholism (four patients). Colon disease was identified in 15 of 24 patients (63%) and endocarditis in five of 27 patients (18%). Co-infection with Strongyloides stercoralis was identified in 14 of 34 patients (41%), ten of whom were infected with human immunodeficiency virus or human T-lymphotropic virus. Outcomes were described for 37 patients; eight died (22%) and one (3%) had neurological sequelae. S. gallolyticus is an uncommon cause of bacterial meningitis, with specific predisposing conditions. When it is identified, consultation with a cardiologist and gastroenterologist is warranted to rule out underlying endocarditis or colon disease. Stool examinations for Strongyloides stercoralis should be performed in patients who have travelled to or originate from endemic areas. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Perinatal iron deficiency predisposes the developing rat hippocampus to greater injury from mild to moderate hypoxia–ischemia

PubMed Central

Rao, Raghavendra; Tkac, Ivan; Townsend, Elise L; Ennis, Kathleen; Gruetter, Rolf; Georgieff, Michael K

2008-01-01

The hippocampus is injured in both hypoxia–ischemia (HI) and perinatal iron deficiency that are comorbidities in infants of diabetic mothers and intrauterine growth restricted infants. We hypothesized that preexisting perinatal iron deficiency predisposes the hippocampus to greater injury when exposed to a relatively mild HI injury. Iron-sufficient and iron-deficient rats (hematocrit 40% lower and brain iron concentration 55% lower) were subjected to unilateral HI injury of 15, 30, or 45 mins (n = 12 to 13/HI duration) on postnatal day 14. Sixteen metabolite concentrations were measured from an 11 μL volume on the ipsilateral (HI) and contralateral (control) hippocampi 1 week later using in vivo 1H NMR spectroscopy. The concentrations of creatine, glutamate, myo-inositol, and N-acetylaspartate were lower on the control side in the iron-deficient group (P < 0.02, each). Magnetic resonance imaging showed hippocampal injury in the majority of the iron-deficient rats (58% versus 11%, P < 0.0001) with worsening severity with increasing durations of HI (P = 0.0001). Glucose, glutamate, N-acetylaspartate, and taurine concentrations were decreased and glutamine, lactate and myo-inositol concentrations, and glutamate/glutamine ratio were increased on the HI side in the iron-deficient group (P < 0.01, each), mainly in the 30 and 45 mins HI subgroups (P < 0.02, each). These neurochemical changes likely reflect the histochemically detected neuronal injury and reactive astrocytosis in the iron-deficient group and suggest that perinatal iron deficiency predisposes the hippocampus to greater injury from exposure to a relatively mild HI insult. PMID:16868555

Risk factors for systemic reactions to bee venom in British beekeepers.

PubMed

Richter, Alex G; Nightingale, Peter; Huissoon, Aarnoud P; Krishna, Mamidipudi T

2011-02-01

There is a high incidence of systemic reactions (SRs) to bee stings in beekeepers, but the factors predisposing individuals to such responses are not well understood. To identify factors that predispose British beekeepers to SRs and to investigate how beekeepers access specialist services after SRs to bee venom. A link to an online survey was published in the bimonthly magazine and on the Web site of the British Beekeepers Association. The demographic results are presented using descriptive analysis, and a logistic regression model was used to determine risk factors for SRs. There were 852 responses to the questionnaire of which 63% were from male beekeepers; the most common age range was 51 to 60 years. Twenty-eight percent of all responders had experienced a large local reaction and 21% had experienced a SR. Factors that predisposed beekeepers to SRs included female sex, having a family member with bee venom allergy, more than 2 years of beekeeping before a SR, and premedication with an antihistamine before attending the hives. A total of 44% of beekeepers with SRs attended the emergency department because of their symptoms, 16.6% were reviewed by an allergy specialist, and only 18% carried an adrenaline autoinjector. Logistic regression analysis identified a number of novel factors to be associated with the development of SRs. Rates of attendance at the emergency department, allergy specialist review, and carriage of adrenaline were low, highlighting a need for education in the beekeeping community and among health care professionals. Copyright © 2011 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Predictors of Adolescent Health Care Utilization

ERIC Educational Resources Information Center

Vingilis, Evelyn; Wade, Terrance; Seeley, Jane

2007-01-01

This study, using Andersen's health care utilization model, examined how predisposing characteristics, enabling resources, need, personal health practices, and psychological factors influence health care utilization using a nationally representative, longitudinal sample of Canadian adolescents. Second, this study examined whether this process…

A realist review of mobile phone-based health interventions for non-communicable disease management in sub-Saharan Africa.

PubMed

Opoku, Daniel; Stephani, Victor; Quentin, Wilm

2017-02-06

The prevalence of non-communicable diseases (NCDs) is increasing in sub-Saharan Africa. At the same time, the use of mobile phones is rising, expanding the opportunities for the implementation of mobile phone-based health (mHealth) interventions. This review aims to understand how, why, for whom, and in what circumstances mHealth interventions against NCDs improve treatment and care in sub-Saharan Africa. Four main databases (PubMed, Cochrane Library, Web of Science, and Google Scholar) and references of included articles were searched for studies reporting effects of mHealth interventions on patients with NCDs in sub-Saharan Africa. All studies published up until May 2015 were included in the review. Following a realist review approach, middle-range theories were identified and integrated into a Framework for Understanding the Contribution of mHealth Interventions to Improved Access to Care for patients with NCDs in sub-Saharan Africa. The main indicators of the framework consist of predisposing characteristics, needs, enabling resources, perceived usefulness, and perceived ease of use. Studies were analyzed in depth to populate the framework. The search identified 6137 titles for screening, of which 20 were retained for the realist synthesis. The contribution of mHealth interventions to improved treatment and care is that they facilitate (remote) access to previously unavailable (specialized) services. Three contextual factors (predisposing characteristics, needs, and enabling resources) influence if patients and providers believe that mHealth interventions are useful and easy to use. Only if they believe mHealth to be useful and easy to use, will mHealth ultimately contribute to improved access to care. The analysis of included studies showed that the most important predisposing characteristics are a positive attitude and a common language of communication. The most relevant needs are a high burden of disease and a lack of capacity of first-contact providers. Essential enabling resources are the availability of a stable communications network, accessible maintenance services, and regulatory policies. Policy makers and program managers should consider predisposing characteristics and needs of patients and providers as well as the necessary enabling resources prior to the introduction of an mHealth intervention. Researchers would benefit from placing greater attention on the context in which mHealth interventions are being implemented instead of focusing (too strongly) on the technical aspects of these interventions.

The Impact of Healthcare Workers Job Environment on Their Mental-emotional Health. Coping Strategies: The Case of a Local General Hospital.

PubMed

Koinis, Aristotelis; Giannou, Vasiliki; Drantaki, Vasiliki; Angelaina, Sophia; Stratou, Elpida; Saridi, Maria

2015-04-13

Workplace stress can influence healthcare professionals' physical and emotional well-being by curbing their efficiency and having a negative impact on their overall quality of life. The aim of the present study was to investigate the impact that work environment in a local public general hospital can have on the health workers' mental-emotional health and find strategies in order to cope with negative consequences. The study took place from July 2010 to October 2010. Our sample consisted of 200 healthcare professionals aged 21-58 years working in a 240-bed general hospital and the response rate was 91.36%). Our research protocol was first approved by the hospital's review board. A standardized questionnaire that investigates strategies for coping with stressful conditions was used. A standardized questionnaire was used in the present study Coping Strategies for Stressful Events, evaluating the strategies that persons employ in order to overcome a stressful situation or event. The questionnaire was first tested for validity and reliability which were found satisfactory (Cronbach's α=0.862). Strict anonymity of the participants was guaranteed. The SPSS 16.0 software was used for the statistical analysis. Regression analysis showed that health professionals' emotional health can be influenced by strategies for dealing with stressful events, since positive re-assessment, quitting and seeking social support are predisposing factors regarding the three first quality of life factors of the World Health Organization Quality of Life - BREF. More specifically, for the physical health factor, positive re-assessment (t=3.370, P=0.001) and quitting (t=-2.564, P=0.011) are predisposing factors. For the 'mental health and spirituality' regression model, positive re-assessment (t=5.528, P=0.000) and seeking social support (t=-1.991, P=0.048) are also predisposing factors, while regarding social relationships positive re-assessment (t=4.289, P=0.000) is a predisposing factor. According to our findings, there was a notable lack of workplace stress management strategies, which the participants usually perceive as a lack of interest on behalf of the management regarding their emotional state. Some significant factors for lowering workplace stress were found to be the need to encourage and morally reward the staff and also to provide them with opportunities for further or continuous education.

New genes linked to lung cancer susceptibility in Asian women

Cancer.gov

An international group of scientists has identified three genes that predispose Asian women who have never smoked to lung cancer. The discovery of specific genetic variations, which have not previously been associated with lung cancer risk in other popul

Structure and Style in Career Decision Making.

ERIC Educational Resources Information Center

Kortas, Linda; And Others

1992-01-01

The Career Decision Scale, Assessment of Career Decision Making, and Cognitive Differentiation Grid were administered to 598 community college students. Results indicated a relationship between decision-making styles and vocational construct structure. Poorly developed vocational schemas predispose individuals toward dependent and intuitive…

Alcoholism and Suicide.

ERIC Educational Resources Information Center

Roy, Alec; Linnoila, Markku

1986-01-01

Reviews knowledge about suicide in alcoholism: how commonly suicide among alcoholics occurs; which alcoholics commit suicide and why; suicide among alcoholic women and alcoholic physicians; possible predisposing biological factors; possible linkages with depression, adverse life events, and personality disorder; and future research and directions.…

Melioidosis Acquired by Traveler to Nigeria

PubMed Central

Salam, Alex P.; Khan, Nisa; Malnick, Henry; Kenna, Dervla T.D.; Dance, David A.B.

2011-01-01

We describe melioidosis associated with travel to Nigeria in a woman with diabetes, a major predisposing factor for this infection. With the prevalence of diabetes projected to increase dramatically in many developing countries, the global reach of melioidosis may expand. PMID:21762592

The evaluation of unmanned aerial system-based photogrammetry and terrestrial laser scanning to generate DEMs of agricultural watersheds

NASA Astrophysics Data System (ADS)

Ouédraogo, Mohamar Moussa; Degré, Aurore; Debouche, Charles; Lisein, Jonathan

2014-06-01

Agricultural watersheds tend to be places of intensive farming activities that permanently modify their microtopography. The surface characteristics of the soil vary depending on the crops that are cultivated in these areas. Agricultural soil microtopography plays an important role in the quantification of runoff and sediment transport because the presence of crops, crop residues, furrows and ridges may impact the direction of water flow. To better assess such phenomena, 3-D reconstructions of high-resolution agricultural watershed topography are essential. Fine-resolution topographic data collection technologies can be used to discern highly detailed elevation variability in these areas. Knowledge of the strengths and weaknesses of existing technologies used for data collection on agricultural watersheds may be helpful in choosing an appropriate technology. This study assesses the suitability of terrestrial laser scanning (TLS) and unmanned aerial system (UAS) photogrammetry for collecting the fine-resolution topographic data required to generate accurate, high-resolution digital elevation models (DEMs) in a small watershed area (12 ha). Because of farming activity, 14 TLS scans (≈ 25 points m- 2) were collected without using high-definition surveying (HDS) targets, which are generally used to mesh adjacent scans. To evaluate the accuracy of the DEMs created from the TLS scan data, 1098 ground control points (GCPs) were surveyed using a real time kinematic global positioning system (RTK-GPS). Linear regressions were then applied to each DEM to remove vertical errors from the TLS point elevations, errors caused by the non-perpendicularity of the scanner's vertical axis to the local horizontal plane, and errors correlated with the distance to the scanner's position. The scans were then meshed to generate a DEMTLS with a 1 × 1 m spatial resolution. The Agisoft PhotoScan and MicMac software packages were used to process the aerial photographs and generate a DEMPSC (Agisoft PhotoScan) and DEMMCM (MicMac), respectively, with spatial resolutions of 1 × 1 m. Comparing the DEMs with the 1098 GCPs showed that the DEMTLS was the most accurate data product, with a root mean square error (RMSE) of 4.5 cm, followed by the DEMMCM and the DEMPSC, which had RMSE values of 9.0 and 13.9 cm, respectively. The DEMPSC had absolute errors along the border of the study area that ranged from 15.0 to 52.0 cm, indicating the presence of systematic errors. Although the derived DEMMCM was accurate, an error analysis along a transect showed that the errors in the DEMMCM data tended to increase in areas of lower elevation. Compared with TLS, UAS is a promising tool for data collection because of its flexibility and low operational cost. However, improvements are needed in the photogrammetric processing of the aerial photographs to remove non-linear distortions.

Validating modelled data on major and trace element deposition in southern Germany using Sphagnum moss

NASA Astrophysics Data System (ADS)

Kempter, Heike; Krachler, Michael; Shotyk, William; Zaccone, Claudio

2017-10-01

Sphagnum mosses were collected from four ombrotrophic bogs in two regions of southern Germany: Upper Bavaria (Oberbayern, OB) and the Northern Black Forest (Nordschwarzwald, NBF). Surfaces of Sphagnum carpets were marked with plastic mesh and, one year later, plant matter was harvested and productivity determined. Major and trace element concentrations (Ag, Al, As, Ba, Bi, Cd, Co, Cr, Cu, Fe, Mn, Mo, Pb, Rb, Sb, Sc, Sr, Th, Ti, Tl, U, V, Zn) were determined in acid digests using sector field ICP-MS. Up to 12 samples (40 × 40 cm) were collected per site, and 6-10 sites investigated per bog. Variation in element accumulation rates within a bog is mostly the result of the annual production rate of the Sphagnum mosses which masks not only the impact of site effects, such as microtopography and the presence of dwarf trees, but also local and regional conditions, including land use in the surrounding area, topography, etc. The difference in productivity between peat bogs results in distinctly higher element accumulation rates at the NBF bogs compared to those from OB for all studied elements. The comparison with the European Monitoring and Evaluation Program (EMEP; wet-only and total deposition) and Modelling of Air Pollutants and Ecosystem Impact (MAPESI; total deposition) data shows that accumulation rates obtained using Sphagnum are in the same range of published values for direct measurements of atmospheric deposition of As, Cd, Cu, Co, Pb, and V in both regions. The accordance is very dependent on how atmospheric deposition rates were obtained, as different models to calculate the deposition rates may yield different fluxes even for the same region. In future studies of atmospheric deposition of trace metals, both Sphagnum moss and deposition collectors have to be used on the same peat bog and results compared. Antimony, however, shows considerable discrepancy, because it is either under-estimated by Sphagnum moss or over-estimated by both atmospheric deposition models. Atmospheric deposition data obtained from sampling in open fields is unlikely to always perfectly match data obtained using living Sphagnum moss from bogs. In fact, plant uptake and biochemical utilization by living moss may affect accumulation rates of those elements that are essential for plant nutrition (macro and micronutrients), which is clearly seen in the data presented here for Mn, Fe and Zn. Furthermore, Sphagnum moss is a unique receptor, with its characteristic roughness and chemical complexity. These two aspects, combined with conditions found on the bog surface (variations in microtopography, shrubs, trees, wetness, snow cover, etc.), result in a unique type of interception and retention. Despite all these factors, the comparison with modelled data shows that Sphagnum moss is a good indicator of atmospheric deposition at least in a semi-quantitative manner and certainly reflects inputs to terrestrial ecosystems.

Preputial calculus in a neurologically-impaired child.

PubMed

Spataru, R I; Iozsa, D A; Ivanov, M

2015-02-01

Preputial calculi are rarely encountered in childhood. A 5-year-old boy with symptoms of chronic balanoposthitis. A preputial stone was documented and removed at circumcision. Uneventful postoperative recovery. In children, association between phimosis and neurologic impairment represent predisposing condition for preputial stone formation.

Ulcerative Vaginitis Due to Torulopsis Glabrata: A Case Report

PubMed Central

Clark, John F. J.; Faggett, Timothy; Peters, Barbara; Sampson, Calvin C.

1978-01-01

A patient with ulcerative vaginitis is presented. The differential diagnosis included malignant ulcer, chancroid, and granuloma venereum. Torulopsis glabrata vaginitis, which was subsequently proven, responded successfully to clotrimazole suppositories. Predisposing and related factors and isolation and identification procedures are discussed. PMID:569709

Fournier's gangrene: non-clostridial gas gangrene of the perineum and diabetes mellitus.

PubMed Central

Lamerton, A J

1986-01-01

Three successfully managed cases of Fournier's gangrene, all with diabetes, are reported. A simple bacteriological classification is offered and the importance of diabetes mellitus as a predisposing factor is stressed. Images Figure 1. Figure 2. Figure 3. PMID:3701767

Evaluation of Genetic Susceptibility to Childhood Allergy and Asthma in an African American Urban Population

EPA Science Inventory

Background: Asthma and allergy represent complex phenotypes, which disproportionately burden ethnic minorities in the United States. Strong evidence for genomic factors predisposing subjects to asthma/allergy is available. However, methods to utilize this information to identify ...

Headache and Decompression Sickness: Type I or Type II?

DTIC Science & Technology

2001-06-01

criteria for Type I instead of Type II DCS. This includes no clear alternative diagnosis, a localized headache along the suture, and no nerologic findings...page survey. Here, demographic information, exposure data, predisposing factors, symptom onset, symptoms and signs, diagnosis, disease progression

Heat Exhaustion in a Rat Model: Lithium as a Biochemical Probe.

DTIC Science & Technology

1988-11-08

thought to predispose to heat-induced illness include amount of exertion, prior conditioning, pre-existing cardiovascular disease, diabetes mellitus...results in altered distribution of body water, sodium depletion, potassium wasting, polyuria , and abnormal thermoregulation (2,3,8-17). Each of

Medical diagnostics for indoor mold exposure.

PubMed

Hurraß, Julia; Heinzow, Birger; Aurbach, Ute; Bergmann, Karl-Christian; Bufe, Albrecht; Buzina, Walter; Cornely, Oliver A; Engelhart, Steffen; Fischer, Guido; Gabrio, Thomas; Heinz, Werner; Herr, Caroline E W; Kleine-Tebbe, Jörg; Klimek, Ludger; Köberle, Martin; Lichtnecker, Herbert; Lob-Corzilius, Thomas; Merget, Rolf; Mülleneisen, Norbert; Nowak, Dennis; Rabe, Uta; Raulf, Monika; Seidl, Hans Peter; Steiß, Jens-Oliver; Szewszyk, Regine; Thomas, Peter; Valtanen, Kerttu; Wiesmüller, Gerhard A

2017-04-01

In April 2016, the German Society of Hygiene, Environmental Medicine and Preventative Medicine (Gesellschaft für Hygiene, Umweltmedizin und Präventivmedizin (GHUP)) together with other scientific medical societies, German and Austrian medical societies, physician unions and experts has provided an AWMF (Association of the Scientific Medical Societies) guideline 'Medical diagnostics for indoor mold exposure'. This guideline shall help physicians to advise and treat patients exposed indoors to mold. Indoor mold growth is a potential health risk, even without a quantitative and/or causal association between the occurrence of individual mold species and health effects. Apart from the allergic bronchopulmonary aspergillosis (ABPA) and the mycoses caused by mold, there is only sufficient evidence for the following associations between moisture/mold damages and different health effects: Allergic respiratory diseases, asthma (manifestation, progression, exacerbation), allergic rhinitis, exogenous allergic alveolitis and respiratory tract infections/bronchitis. In comparison to other environmental allergens, the sensitizing potential of molds is estimated to be low. Recent studies show a prevalence of sensitization of 3-10% in the total population of Europe. The evidence for associations to mucous membrane irritation and atopic eczema (manifestation, progression, exacerbation) is classified as limited or suspected. Inadequate or insufficient evidence for an association is given for COPD, acute idiopathic pulmonary hemorrhage in children, rheumatism/arthritis, sarcoidosis, and cancer. The risk of infections from indoor molds is low for healthy individuals. Only molds that are capable to form toxins can cause intoxications. The environmental and growth conditions and especially the substrate determine whether toxin formation occurs, but indoor air concentrations are always very low. In the case of indoor moisture/mold damages, everyone can be affected by odor effects and/or impairment of well-being. Predisposing factors for odor effects can be given by genetic and hormonal influences, imprinting, context and adaptation effects. Predisposing factors for impairment of well-being are environmental concerns, anxieties, conditioning and attributions as well as a variety of diseases. Risk groups that must be protected are patients with immunosuppression and with mucoviscidosis (cystic fibrosis) with regard to infections and individuals with mucoviscidosis and asthma with regard to allergies. If an association between mold exposure and health effects is suspected, the medical diagnosis includes medical history, physical examination, conventional allergy diagnosis, and if indicated, provocation tests. For the treatment of mold infections, it is referred to the AWMF guidelines for diagnosis and treatment of invasive Aspergillus infections. Regarding mycotoxins, there are currently no validated test methods that could be used in clinical diagnostics. From the perspective of preventive medicine, it is important that mold damages cannot be tolerated in indoor environments. Copyright © 2016 Elsevier GmbH. All rights reserved.

The Effects of Geography and Spatial Behavior on Health Care Utilization among the Residents of a Rural Region

PubMed Central

Arcury, Thomas A; Gesler, Wilbert M; Preisser, John S; Sherman, Jill; Spencer, John; Perin, Jamie

2005-01-01

Objective This analysis determines the importance of geography and spatial behavior as predisposing and enabling factors in rural health care utilization, controlling for demographic, social, cultural, and health status factors. Data Sources A survey of 1,059 adults in 12 rural Appalachian North Carolina counties. Study Design This cross-sectional study used a three-stage sampling design stratified by county and ethnicity. Preliminary analysis of health services utilization compared weighted proportions of number of health care visits in the previous 12 months for regular check-up care, chronic care, and acute care across geographic, sociodemographic, cultural, and health variables. Multivariable logistic models identified independent correlates of health services utilization. Data Collection Methods Respondents answered standard survey questions. They located places in which they engaged health related and normal day-to-day activities; these data were entered into a geographic information system for analysis. Principal Findings Several geographic and spatial behavior factors, including having a driver's license, use of provided rides, and distance for regular care, were significantly related to health care utilization for regular check-up and chronic care in the bivariate analysis. In the multivariate model, having a driver's license and distance for regular care remained significant, as did several predisposing (age, gender, ethnicity), enabling (household income), and need (physical and mental health measures, number of conditions). Geographic measures, as predisposing and enabling factors, were related to regular check-up and chronic care, but not to acute care visits. Conclusions These results show the importance of geographic and spatial behavior factors in rural health care utilization. They also indicate continuing inequity in rural health care utilization that must be addressed in public policy. PMID:15663706

Highlights Regarding Host Predisposing Factors to Recurrent Vulvovaginal Candidiasis: Chronic Stress and Reduced Antioxidant Capacity.

PubMed

Akimoto-Gunther, Luciene; Bonfim-Mendonça, Patrícia de Souza; Takahachi, Gisele; Irie, Mary Mayumi T; Miyamoto, Sônia; Consolaro, Márcia Edilaine Lopes; Svidzinsk, Terezinha I Estivalet

2016-01-01

We studied host factors that could predispose women to develop recurrent vulvovaginal candidiasis (RVVC), including glycemia, insulin resistance, chronic stress, antioxidant capacity, overall immune status, local inflammation and vaginal microbiota. The presence of yeasts in vaginal culture was screened in 277 women, with or without signs and symptoms of VVC and RVVC. The presence of an inflammatory process and microbiota were analyzed through vaginal bacterioscopy and cervical-vaginal cytology, respectively. Fasting-blood samples were collected by standard venipuncture for biochemical analyses. Flow cytometry was employed to obtain the T helper/T cytotoxic lymphocyte ratio, and insulin resistance was assessed by the HOMA index (HI). Yeasts were isolated from 71 (26%) women: 23 (32.4%) with a positive culture but without symptoms (COL), 22 (31%) in an acute episode (VVC), and 26 (36.6%) with RVVC. C. albicans was the main yeast isolated in all clinical profiles. The control group (negative culture) comprised 206 women. Diabetes mellitus and insulin resistance were more associated with the positive-culture groups (COL, VVC and RVVC) than with negative ones. The RVVC group showed lower mean levels of cortisol than the control group and lower antioxidant capacity than all other groups. The T Helper/T cytotoxic lymphocyte ratio was similar in all groups. The RVVC group showed a similar level of vaginal inflammation to the control group, and lower than in the COL and VVC groups. Only the CVV group showed a reduction in vaginal lactobacillus microbiota. Our data suggest that both chronic stress (decreased early-morning cortisol levels) and reduced antioxidant capacity can be host predisposing factors to RVVC.

Highlights Regarding Host Predisposing Factors to Recurrent Vulvovaginal Candidiasis: Chronic Stress and Reduced Antioxidant Capacity

PubMed Central

Akimoto-Gunther, Luciene; Bonfim-Mendonça, Patrícia de Souza; Takahachi, Gisele; Irie, Mary Mayumi T.; Miyamoto, Sônia; Consolaro, Márcia Edilaine Lopes; Svidzinsk, Terezinha I. Estivalet

2016-01-01

We studied host factors that could predispose women to develop recurrent vulvovaginal candidiasis (RVVC), including glycemia, insulin resistance, chronic stress, antioxidant capacity, overall immune status, local inflammation and vaginal microbiota. The presence of yeasts in vaginal culture was screened in 277 women, with or without signs and symptoms of VVC and RVVC. The presence of an inflammatory process and microbiota were analyzed through vaginal bacterioscopy and cervical-vaginal cytology, respectively. Fasting-blood samples were collected by standard venipuncture for biochemical analyses. Flow cytometry was employed to obtain the T helper/T cytotoxic lymphocyte ratio, and insulin resistance was assessed by the HOMA index (HI). Yeasts were isolated from 71 (26%) women: 23 (32.4%) with a positive culture but without symptoms (COL), 22 (31%) in an acute episode (VVC), and 26 (36.6%) with RVVC. C. albicans was the main yeast isolated in all clinical profiles. The control group (negative culture) comprised 206 women. Diabetes mellitus and insulin resistance were more associated with the positive-culture groups (COL, VVC and RVVC) than with negative ones. The RVVC group showed lower mean levels of cortisol than the control group and lower antioxidant capacity than all other groups. The T Helper/T cytotoxic lymphocyte ratio was similar in all groups. The RVVC group showed a similar level of vaginal inflammation to the control group, and lower than in the COL and VVC groups. Only the CVV group showed a reduction in vaginal lactobacillus microbiota. Our data suggest that both chronic stress (decreased early-morning cortisol levels) and reduced antioxidant capacity can be host predisposing factors to RVVC. PMID:27415762

N-acetyltransferase 2 (NAT2) gene polymorphism as a predisposing factor for phenytoin intoxication in tuberculous meningitis or tuberculoma patients having seizures - A pilot study.

PubMed

Adole, Prashant S; Kharbanda, Parampreet S; Sharma, Sadhna

2016-05-01

Simultaneous administration of phenytoin and isoniazid (INH) in tuberculous meningitis (TBM) or tuberculoma patients with seizures results in higher plasma phenytoin level and thus phenytoin intoxication. N-acetyltransferase 2 (NAT2) enzyme catalyses two acetylation reactions in INH metabolism and NAT2 gene polymorphism leads to slow and rapid acetylators. The present study was aimed to evaluate the effect of allelic variants of N-acetyltransferase 2 (NAT2) gene as a predisposing factor for phenytoin toxicity in patients with TBM or tuberculoma having seizures, and taking INH and phenytoin simultaneously. Sixty patients with TBM or tuberculoma with seizures and taking INH and phenytoin simultaneously for a minimum period of seven days were included in study. Plasma phenytoin was measured by high performance liquid chromatography. NAT2 gene polymorphism was studied using restriction fragment length polymorphism and allele specific PCR. The patients were grouped into those having phenytoin intoxication and those with normal phenytoin level, and also classified as rapid or slow acetylators by NAT2 genotyping. Genotypic analysis showed that of the seven SNPs (single nucleotide polymorphisms) of NAT2 gene studied, six mutations were found to be associated with phenytoin intoxication. For rs1041983 (C282T), rs1799929 (C481T), rs1799931 (G857A), rs1799930 (G590A), rs1208 (A803G) and rs1801280 (T341C) allelic variants, the proportion of homozygous mutant was higher in phenytoin intoxicated group than in phenytoin non-intoxicated group. Homozygous mutant allele of NAT2 gene at 481site may act as a predisposing factor for phenytoin intoxication among TBM or tuberculoma patients having seizures.

Are prostatic calculi independent predictive factors of lower urinary tract symptoms?

PubMed Central

Park, Sung-Woo; Nam, Jong-Kil; Lee, Sang-Don; Chung, Moon-Kee

2010-01-01

We determined the correlation between prostatic calculi and lower urinary tract symptoms (LUTS), as well as the predisposing factors of prostatic calculi. Of the 1 527 patients who presented at our clinic for LUTS, 802 underwent complete evaluations, including transrectal ultrasonography, voided bladder-3 specimen and international prostatic symptoms score (IPSS). A total of 335 patients with prostatic calculi and 467 patients without prostatic calculi were divided into calculi and no calculi groups, respectively. Predictive factors of severe LUTS and prostatic calculi were determined using uni/multivariate analysis. The overall IPSS score was 15.7 ± 9.2 and 14.1 ± 9.2 in the calculi and no calculi group, respectively (P = 0.013). The maximum flow rate was 12.1 ± 6.9 and 14.2 ± 8.2 mL s−1 in the calculi and no calculi group, respectively (P = 0.003). On univariate analysis for predicting factors of severe LUTS, differences on age (P = 0.042), prostatic calculi (P = 0.048) and prostatitis (P = 0.018) were statistically significant. However, on multivariate analysis, no factor was significant. On multivariate analysis for predisposing factors of prostatic calculi, differences on age (P < 0.001) and prostate volume (P = 0.001) were significant. To our knowledge, patients who have prostatic calculi complain of more severe LUTS. However, prostatic calculi are not an independent predictive factor of severe LUTS. Therefore, men with prostatic calculi have more severe LUTS not only because of prostatic calculi but also because of age and other factors. In addition, old age and large prostate volume are independent predisposing factors for prostatic calculi. PMID:19966831

Does genetic heterogeneity account for the divergent risk of type 2 diabetes in South Asian and white European populations?

PubMed

Sohani, Zahra N; Deng, Wei Q; Pare, Guillaume; Meyre, David; Gerstein, Hertzel C; Anand, Sonia S

2014-11-01

South Asians are up to four times more likely to develop type 2 diabetes than white Europeans. It is postulated that the higher prevalence results from greater genetic risk. To evaluate this hypothesis, we: (1) systematically reviewed the literature for single nucleotide polymorphisms (SNPs) predisposing to type 2 diabetes in South Asians; (2) compared risk estimates, risk alleles and risk allele frequencies of predisposing SNPs between South Asians and white Europeans; and (3) tested the association of novel SNPs discovered from South Asians in white Europeans. MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL) and the Cochrane registry were searched for studies of genetic variants associated with type 2 diabetes in South Asians. Meta-analysis estimates for common and novel bi-allelic SNPs in South Asians were compared with white Europeans from the DIAbetes Genetics Replication And Meta-analysis (DIAGRAM) consortium. The population burden from predisposing SNPs was assessed using a genotype score. Twenty-four SNPs from 21 loci were associated with type 2 diabetes in South Asians after meta-analysis. The majority of SNPs increase odds of the disorder by 15-35% per risk allele. No substantial differences appear to exist in risk estimates between South Asians and white Europeans from SNPs common to both groups, and the population burden also does not differ. Eight of the 24 are novel SNPs discovered from South Asian genome-wide association studies, some of which show nominal associations with type 2 diabetes in white Europeans. Based on current literature there is no strong evidence to indicate that South Asians possess a greater genetic risk of type 2 diabetes than white Europeans.

Cultural practices and sexual risk behaviour among adolescent orphans and non-orphans: a qualitative study on perceptions from a community in western Kenya

PubMed Central

2014-01-01

Background This study explored community perceptions of cultural beliefs and practices that may increase sexual risk behaviour of adolescents, to understand more about meaning they hold within the culture and how they expose adolescent orphans and non-orphans to higher risks in a high HIV and teenage pregnancy prevalence context. Methods Using a qualitative descriptive cross-sectional design 14 focus group discussions were conducted with 78 adolescents and 68 parents/guardians purposively selected to represent their communities. Thirteen key informant interviews were also conducted with community leaders, health care and child welfare workers, and adolescents who were also selected purposively. The two methods were used to explore how cultural beliefs and practices predispose adolescent orphans and non- orphans to risky sexual behaviours. Data were analysed through line-by-line coding, grouped into families and retrieved as themes and sub-themes. Results Identified cultural practices that predisposed adolescents orphans and non-orphans to risky sexual behaviours included: adolescent sleeping arrangements, funeral ceremonies, replacing a deceased married daughter with her younger sister in marriage, widow inheritance among boys, early marriage among girls, and preference for boys/sons. Cultural risks perceived to equally affect both orphans and non-orphans were sleeping arrangements, funeral ceremonies, and sister replacement. Factors associated more with orphans than non-orphans were widow inheritance among boys and a preference for boy over girl children. Conclusions Adolescent sexual risk reduction programs should be developed considering the specific cultural context, using strategies that empower communities to challenge the widely accepted cultural norms that may predispose young people in general to sexual risks while targeting those that unequally influence orphans. PMID:24467940

There's an app for that: content analysis of paid health and fitness apps.

PubMed

West, Joshua H; Hall, P Cougar; Hanson, Carl L; Barnes, Michael D; Giraud-Carrier, Christophe; Barrett, James

2012-05-14

The introduction of Apple's iPhone provided a platform for developers to design third-party apps, which greatly expanded the functionality and utility of mobile devices for public health. This study provides an overview of the developers' written descriptions of health and fitness apps and appraises each app's potential for influencing behavior change. Data for this study came from a content analysis of health and fitness app descriptions available on iTunes during February 2011. The Health Education Curriculum Analysis Tool (HECAT) and the Precede-Proceed Model (PPM) were used as frameworks to guide the coding of 3336 paid apps. Compared to apps with a cost less than US $0.99, apps exceeding US $0.99 were more likely to be scored as intending to promote health or prevent disease (92.55%, 1925/3336 vs 83.59%, 1411/3336; P<.001), to be credible or trustworthy (91.11%, 1895/3336 vs 86.14%, 1454/3349; P<.001), and more likely to be used personally or recommended to a health care client (72.93%, 1517/2644 vs 66.77%, 1127/2644; P<.001). Apps related to healthy eating, physical activity, and personal health and wellness were more common than apps for substance abuse, mental and emotional health, violence prevention and safety, and sexual and reproductive health. Reinforcing apps were less common than predisposing and enabling apps. Only 1.86% (62/3336) of apps included all 3 factors (ie, predisposing, enabling, and reinforcing). Development efforts could target public health behaviors for which few apps currently exist. Furthermore, practitioners should be cautious when promoting the use of apps as it appears most provide health-related information (predisposing) or make attempts at enabling behavior, with almost none including all theoretical factors recommended for behavior change.

Differential Ability of Pandemic and Seasonal H1N1 Influenza A Viruses To Alter the Function of Human Neutrophils.

PubMed

Malachowa, Natalia; Freedman, Brett; Sturdevant, Daniel E; Kobayashi, Scott D; Nair, Vinod; Feldmann, Friederike; Starr, Tregei; Steele-Mortimer, Olivia; Kash, John C; Taubenberger, Jeffery K; Feldmann, Heinz; DeLeo, Frank R

2018-01-01

Neutrophils are essential cells of host innate immunity. Although the role of neutrophils in defense against bacterial and fungal infections is well characterized, there is a relative paucity of information about their role against viral infections. Influenza A virus (IAV) infection can be associated with secondary bacterial coinfection, and it has long been posited that the ability of IAV to alter normal neutrophil function predisposes individuals to secondary bacterial infections. To better understand this phenomenon, we evaluated the interaction of pandemic or seasonal H1N1 IAV with human neutrophils isolated from healthy persons. These viruses were ingested by human neutrophils and elicited changes in neutrophil gene expression that are consistent with an interferon-mediated immune response. The viability of neutrophils following coculture with either pandemic or seasonal H1N1 IAV was similar for up to 18 h of culture. Notably, neutrophil exposure to seasonal (but not pandemic) IAV primed these leukocytes for enhanced functions, including production of reactive oxygen species and bactericidal activity. Taken together, our results are at variance with the universal idea that IAV impairs neutrophil function directly to predispose individuals to secondary bacterial infections. Rather, we suggest that some strains of IAV prime neutrophils for enhanced bacterial clearance. IMPORTANCE A long-standing notion is that IAV inhibits normal neutrophil function and thereby predisposes individuals to secondary bacterial infections. Here we report that seasonal H1N1 IAV primes human neutrophils for enhanced killing of Staphylococcus aureus . Moreover, we provide a comprehensive view of the changes in neutrophil gene expression during interaction with seasonal or pandemic IAV and report how these changes relate to functions such as bactericidal activity. This study expands our knowledge of IAV interactions with human neutrophils.

Differential Ability of Pandemic and Seasonal H1N1 Influenza A Viruses To Alter the Function of Human Neutrophils

PubMed Central

Malachowa, Natalia; Freedman, Brett; Sturdevant, Daniel E.; Kobayashi, Scott D.; Nair, Vinod; Feldmann, Friederike; Starr, Tregei; Steele-Mortimer, Olivia; Kash, John C.; Taubenberger, Jeffery K.; Feldmann, Heinz

2018-01-01

ABSTRACT Neutrophils are essential cells of host innate immunity. Although the role of neutrophils in defense against bacterial and fungal infections is well characterized, there is a relative paucity of information about their role against viral infections. Influenza A virus (IAV) infection can be associated with secondary bacterial coinfection, and it has long been posited that the ability of IAV to alter normal neutrophil function predisposes individuals to secondary bacterial infections. To better understand this phenomenon, we evaluated the interaction of pandemic or seasonal H1N1 IAV with human neutrophils isolated from healthy persons. These viruses were ingested by human neutrophils and elicited changes in neutrophil gene expression that are consistent with an interferon-mediated immune response. The viability of neutrophils following coculture with either pandemic or seasonal H1N1 IAV was similar for up to 18 h of culture. Notably, neutrophil exposure to seasonal (but not pandemic) IAV primed these leukocytes for enhanced functions, including production of reactive oxygen species and bactericidal activity. Taken together, our results are at variance with the universal idea that IAV impairs neutrophil function directly to predispose individuals to secondary bacterial infections. Rather, we suggest that some strains of IAV prime neutrophils for enhanced bacterial clearance. IMPORTANCE A long-standing notion is that IAV inhibits normal neutrophil function and thereby predisposes individuals to secondary bacterial infections. Here we report that seasonal H1N1 IAV primes human neutrophils for enhanced killing of Staphylococcus aureus. Moreover, we provide a comprehensive view of the changes in neutrophil gene expression during interaction with seasonal or pandemic IAV and report how these changes relate to functions such as bactericidal activity. This study expands our knowledge of IAV interactions with human neutrophils. PMID:29299535

Explaining the relationship between temperament and symptoms of psychiatric disorders from preschool to middle childhood: hybrid fixed and random effects models of Norwegian and Spanish children.

PubMed

Wichstrøm, Lars; Penelo, Eva; Rensvik Viddal, Kristine; de la Osa, Nuria; Ezpeleta, Lourdes

2018-03-01

Four explanations for the concurrent and prospective associations between temperament and psychopathology in children have been suggested: predisposition, complication/scar, common cause/continuity, and pathoplasty/exacerbation. Because the confounding effects of common causes have not been ruled out in prior work, the support for the various explanations is uncertain. Screen-stratified community samples of 4-year olds in Trondheim, Norway (n = 1,042), and 3-year olds in Barcelona, Spain (n = 622), were assessed biennially for symptoms of attention-deficit/hyperactivity (ADHD), oppositional defiant (ODD), conduct (CD), anxiety, and depressive disorders through interviewer-based psychiatric interviews across four waves of data collection. The parents completed child temperament ratings. The data were analyzed with random and fixed effects regression adjusted for all time-invariant unmeasured confounders (e.g., genetics, common methods bias, item overlap). In both Norway and Spain and across ages, negative affect predisposed children to symptoms of all disorders except CD, low effortful control predisposed children to ADHD and ODD-symptoms, and surgency predisposed children to increased ADHD-symptoms. Complication effects were observed in the Spanish children for ADHD-symptoms, which increased surgency and diminished effortful control, and for ODD-symptoms, which decreased surgency. The common cause and pathoplasty/exacerbation explanations were not supported. The present results are consistent with the view that temperament plays a causal role in the development of symptoms of psychiatric disorders in children. Because temperament is malleable, interventions targeting the affective, attentional, and behavioral regulatory components of temperament may reduce psychopathology in children. © 2017 The Authors. Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health.

Cultural practices and sexual risk behaviour among adolescent orphans and non-orphans: a qualitative study on perceptions from a community in Western Kenya.

PubMed

Juma, Milka; Askew, Ian; Alaii, Jane; Bartholomew, L Kay; van den Borne, Bart

2014-01-27

This study explored community perceptions of cultural beliefs and practices that may increase sexual risk behaviour of adolescents, to understand more about meaning they hold within the culture and how they expose adolescent orphans and non-orphans to higher risks in a high HIV and teenage pregnancy prevalence context. Using a qualitative descriptive cross-sectional design 14 focus group discussions were conducted with 78 adolescents and 68 parents/guardians purposively selected to represent their communities. Thirteen key informant interviews were also conducted with community leaders, health care and child welfare workers, and adolescents who were also selected purposively. The two methods were used to explore how cultural beliefs and practices predispose adolescent orphans and non- orphans to risky sexual behaviours. Data were analysed through line-by-line coding, grouped into families and retrieved as themes and sub-themes. Identified cultural practices that predisposed adolescents orphans and non-orphans to risky sexual behaviours included: adolescent sleeping arrangements, funeral ceremonies, replacing a deceased married daughter with her younger sister in marriage, widow inheritance among boys, early marriage among girls, and preference for boys/sons. Cultural risks perceived to equally affect both orphans and non-orphans were sleeping arrangements, funeral ceremonies, and sister replacement. Factors associated more with orphans than non-orphans were widow inheritance among boys and a preference for boy over girl children. Adolescent sexual risk reduction programs should be developed considering the specific cultural context, using strategies that empower communities to challenge the widely accepted cultural norms that may predispose young people in general to sexual risks while targeting those that unequally influence orphans.

Delirium after cardiac surgery: incidence and risk factors†

PubMed Central

Smulter, Nina; Lingehall, Helena Claesson; Gustafson, Yngve; Olofsson, Birgitta; Engström, Karl Gunnar

2013-01-01

OBJECTIVES Delirium after cardiac surgery is a problem with consequences for patients and healthcare. Preventive strategies from known risk factors may reduce the incidence and severity of delirium. The present aim was to explore risk factors behind delirium in older patients undergoing cardiac surgery with cardiopulmonary bypass. METHODS Patients (≥70 years) scheduled for routine cardiac surgery were included (n = 142). The patients were assessed and monitored pre-/postoperatively, and delirium was diagnosed from repeated assessments with the Mini-Mental State Examination and the Organic Brain Syndrome Scale, using the DSM-IV-TR criteria. Variables were analysed by uni-/multivariable logistic regression, including both preoperative variables (predisposing) and those extracted during surgery and in the early postoperative period (precipitating). RESULTS Delirium was diagnosed in 78 patients (54.9%). Delirium was independently associated with both predisposing and precipitating factors (P-value, odds ratio, upper/lower confidence interval): age (0.036, 1.1, 1.0/1.2), diabetes (0.032, 3.5, 1.1/11.0), gastritis/ulcer problems (0.050, 4.0, 1.0/16.1), volume load during operation (0.001, 2.8, 1.5/5.1), ventilator time in ICU (0.042, 1.2, 1.0/1.4), highest temperature recorded in ICU (0.044, 2.2, 1.0/4.8) and sodium concentration in ICU (0.038, 1.2, 1.0/1.4). CONCLUSIONS Delirium was common among older patients undergoing cardiac surgery. Both predisposing and precipitating factors contributed to delirium. When combined, the predictive strength of the model improved. Preventive strategies may be considered, in particular among the precipitating factors. Of interest, delirium was strongly associated with an increased volume load during surgery. PMID:23887126

Taeniasis in non-descript dogs in Ngorongoro, Tanzania: Prevalence and predisposing factors.

PubMed

Swai, Emmanuel S; Miran, Miran B; Kasuku, Ayubu A; Nzalawahe, Jahashi

2016-05-24

The prevalence of taeniasis was determined during the period January to April 2013 in a cross-sectional study of non-descript domestic dogs from the livestock-wildlife ecosystem of Ngorongoro, Tanzania. Taeniid eggs were determined by screening faecal samples using the formalin-ether sedimentation technique. Predisposing factors for dog infection were assessed in relation to demographic, husbandry and management data. Of the 205 faecal samples screened, 150 (73.2%) were positive for taeniid eggs. The prevalence of dogs harbouring taeniid eggs was 80%, 30.2% and 75.3% in the less than 1 year, 1-3 years and greater than 3 years of age groups, respectively. Age group and sex prevalence in dogs did not differ significantly (P > 0.05), although the females showed a marginally higher prevalence (73.8%) in comparison to the males (72.7%). Taeniid eggs were significantly more likely to be found in the faeces of dogs located in Waso (80.6%) and Endulen (75%) than in Malambo (63.2%, P < 0.05). The study revealed that dogs owned and raised by agro-pastoralists were at a lower risk of acquiring Taenia spp. infection (P = 0.001) than those that were raised by pastoralists. The majority of dog owners were not aware of the predisposing factors and the mode of transmission of taeniids. Dogs were frequently fed on viscera, trimmings and the heads of slaughtered animals, and they were not treated for parasitic infections. The findings of this study indicate that taeniasis is prevalent among non-descript dogs in Ngorongoro, underscoring the need for further research and active surveillance to better understand the transmission cycle of Taenia spp. in a wider geographical area in Tanzania.

A rare cause of gastrointestinal phytobezoars: diospyros lotus

PubMed Central

2012-01-01

Aim Diospyros Lotus (“Wild Date Palm of Trabzon or Persimmon”), which has been proven to cause phytobezoars, is a widely consumed fruit in the Black Sea and Northeast Anatolia regions of Turkey. The aim of the present study was to investigate the effects of Diospyros Lotus together with other predisposing factors, on the development of gastrointestinal phytobezoars and to discuss the treatment results in comparison to the literature. Material and method The records of 13 patients, who had been admitted to the General Surgery Clinic of Düzce Atatürk State Hospital between August 2008 and August 2011, were retrospectively reviewed. Demographic characteristics, predisposing factors, clinical and radiological findings, diagnostic and therapeutic methods, and the outcomes of the patients were recorded from the patient files. Written informed consent was obtained from each patient for publication of this research article and accompanying images. Results All the patients had a history of consuming Diospyros Lotus. Of the patients, 30,7% had a history of previous gastric surgery, 30,7% had diabetes mellitus and 23% had dental implants. None of the patients had hypothyroidism, which is another predisposing factor for phytobezoars. The phytobezoars were located in the stomach alone in 23% of the patients, whereas 15,3% was detected in the jejunum and stomach, 15,3% was detected in the jejunum alone, and 46,1% was detected in the ileum alone. All patients were treated with surgery, and there were no deaths. Conclusion Gastric phytobezoars are rare. Preventive measures have particular importance in the management of this condition, which is difficult to treat. For this purpose, excessive consumption of herbal nutrients containing a high amount of indigestible fibers such as Diospyros Lotus should be avoided in patients with a history of gastrointestinal surgery or poor oral and dental health. PMID:22721161

Acute Methanol Poisoning: Prevalence and Predisposing Factors of Haemorrhagic and Non-Haemorrhagic Brain Lesions.

PubMed

Zakharov, Sergey; Kotikova, Katerina; Vaneckova, Manuela; Seidl, Zdenek; Nurieva, Olga; Navratil, Tomas; Caganova, Blazena; Pelclova, Daniela

2016-08-01

The purpose was to study the prevalence and predisposing factors of brain lesions in survivors of acute methanol poisoning. Clinical data on 106 patients with methanol poisoning were collected during the Czech mass poisoning outbreak. Of 83 survivors, in 46 (55%) patients, follow-up examinations including magnetic resonance imaging of brain (MR) were performed 3-8 and 24-28 months after discharge from the hospital. Of 46 patients with a median age of 49 (interquartile range, 35-57) years, 24 (52%) patients had a total of 40 abnormal brain findings with haemorrhagic lesions detected in 15 (33%) and non-haemorrhagic lesions found in 9 (19%) patients. The patients with haemorrhagic brain lesions were more acidemic (lower arterial blood pH, higher base deficit) and had higher glycaemia and lactacidaemia on admission than those without haemorrhages (all p < 0.05). Thirteen of 32 (41%) of patients with systemic anticoagulation and 2 of 14 (14%) of patients without it had haemorrhagic lesions (p = 0.080). Bleeding complications during the treatment occurred in 4 of 15 (27%) patients, and 5 of 15 (33%) patients had conditions predisposing to haemorrhage in the group with haemorrhagic lesions. In three cases with a series of computer tomography (CT)/MR performed during hospitalization, the necrotic lesions in the brain remained non-haemorrhagic during hospitalization and haemorrhagic lesions were detected on the follow-up MR examinations only. No association between brain haemorrhages and systemic anticoagulation during dialysis was found: brain haemorrhages might occur in severely poisoned patients treated without systemic anticoagulation, whereas treatment with high doses of heparin might not lead to brain haemorrhages. © 2016 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

N-acetyltransferase 2 (NAT2) gene polymorphism as a predisposing factor for phenytoin intoxication in tuberculous meningitis or tuberculoma patients having seizures - A pilot study

PubMed Central

Adole, Prashant S.; Kharbanda, Parampreet S.; Sharma, Sadhna

2016-01-01

Background & objectives: Simultaneous administration of phenytoin and isoniazid (INH) in tuberculous meningitis (TBM) or tuberculoma patients with seizures results in higher plasma phenytoin level and thus phenytoin intoxication. N-acetyltransferase 2 (NAT2) enzyme catalyses two acetylation reactions in INH metabolism and NAT2 gene polymorphism leads to slow and rapid acetylators. The present study was aimed to evaluate the effect of allelic variants of N-acetyltransferase 2 (NAT2) gene as a predisposing factor for phenytoin toxicity in patients with TBM or tuberculoma having seizures, and taking INH and phenytoin simultaneously. Methods: Sixty patients with TBM or tuberculoma with seizures and taking INH and phenytoin simultaneously for a minimum period of seven days were included in study. Plasma phenytoin was measured by high performance liquid chromatography. NAT2 gene polymorphism was studied using restriction fragment length polymorphism and allele specific PCR. Results: The patients were grouped into those having phenytoin intoxication and those with normal phenytoin level, and also classified as rapid or slow acetylators by NAT2 genotyping. Genotypic analysis showed that of the seven SNPs (single nucleotide polymorphisms) of NAT2 gene studied, six mutations were found to be associated with phenytoin intoxication. For rs1041983 (C282T), rs1799929 (C481T), rs1799931 (G857A), rs1799930 (G590A), rs1208 (A803G) and rs1801280 (T341C) allelic variants, the proportion of homozygous mutant was higher in phenytoin intoxicated group than in phenytoin non-intoxicated group. Interpretation & conclusions: Homozygous mutant allele of NAT2 gene at 481site may act as a predisposing factor for phenytoin intoxication among TBM or tuberculoma patients having seizures. PMID:27488001

Factors predisposing to consecutive esotropia after surgery to correct intermittent exotropia.

PubMed

Jang, Jung Hyun; Park, Jung Min; Lee, Soo Jung

2012-10-01

To investigate the incidence of and factors predisposing to consecutive esotropia after intermittent exotropia surgery, and to prevent the onset of consecutive esotropia. We retrospectively surveyed 226 patients who had been followed up for more than 1 year after surgery for intermittent exotropia conducted between February 2005 and September 2010. Consecutive esotropia was defined as an esotropia of at least 10 prism diopters (PD) at distance or near at least once in 2 weeks after surgery. Presumed risk factors for consecutive esotropia were analyzed. Gender, age at surgery, average binocular spherical equivalent, anisometropia, high myopia, amblyopia, preoperative angle of deviation, vertical deviation, A-V pattern strabismus, exotropia type, type of surgery, stereopsis, and suppression were investigated to evaluate factors influencing the onset of consecutive esotropia. Consecutive esotropia occurred in 22 patients (9.7 %). Significant correlations with occurrence of the condition were found with high myopia (P = 0.013), amblyopia (P = 0.047), preoperative angle of deviation of 25-40 PD at distance (P = 0.016), deviation at distance - deviation at near > 10 PD (P = 0.041), lateral incomitance (P = 0.007), tenacious proximal convergence fusion type (P = 0.001), unilateral lateral rectus muscle recession and medial rectus muscle resection (P = 0.001). High myopia, amblyopia, and lateral incomitance were predisposing factors for consecutive esotropia. Furthermore, the preoperative angle of deviation at distance, differences between the angle of deviation at near and at distance, the type of intermittent exotropia, and the type of surgery affected the incidence of consecutive esotropia. More attention must be paid to patients with such factors.

Targeted Exome Sequencing of Krebs Cycle Genes Reveals Candidate Cancer-Predisposing Mutations in Pheochromocytomas and Paragangliomas.

PubMed

Remacha, Laura; Comino-Méndez, Iñaki; Richter, Susan; Contreras, Laura; Currás-Freixes, María; Pita, Guillermo; Letón, Rocío; Galarreta, Antonio; Torres-Pérez, Rafael; Honrado, Emiliano; Jiménez, Scherezade; Maestre, Lorena; Moran, Sebastian; Esteller, Manel; Satrústegui, Jorgina; Eisenhofer, Graeme; Robledo, Mercedes; Cascón, Alberto

2017-10-15

Purpose: Mutations in Krebs cycle genes are frequently found in patients with pheochromocytomas/paragangliomas. Disruption of SDH, FH or MDH2 enzymatic activities lead to accumulation of specific metabolites, which give rise to epigenetic changes in the genome that cause a characteristic hypermethylated phenotype. Tumors showing this phenotype, but no alterations in the known predisposing genes, could harbor mutations in other Krebs cycle genes. Experimental Design: We used downregulation and methylation of RBP1, as a marker of a hypermethylation phenotype, to select eleven pheochromocytomas and paragangliomas for targeted exome sequencing of a panel of Krebs cycle-related genes. Methylation profiling, metabolite assessment and additional analyses were also performed in selected cases. Results: One of the 11 tumors was found to carry a known cancer-predisposing somatic mutation in IDH1 A variant in GOT2 , c.357A>T, found in a patient with multiple tumors, was associated with higher tumor mRNA and protein expression levels, increased GOT2 enzymatic activity in lymphoblastic cells, and altered metabolite ratios both in tumors and in GOT2 knockdown HeLa cells transfected with the variant. Array methylation-based analysis uncovered a somatic epigenetic mutation in SDHC in a patient with multiple pheochromocytomas and a gastrointestinal stromal tumor. Finally, a truncating germline IDH3B mutation was found in a patient with a single paraganglioma showing an altered α-ketoglutarate/isocitrate ratio. Conclusions: This study further attests to the relevance of the Krebs cycle in the development of PCC and PGL, and points to a potential role of other metabolic enzymes involved in metabolite exchange between mitochondria and cytosol. Clin Cancer Res; 23(20); 6315-24. ©2017 AACR . ©2017 American Association for Cancer Research.

Prevalence of pseudobulbar affect symptoms and clinical correlates in nursing home residents.

PubMed

Foley, Kevin; Konetzka, R Tamara; Bunin, Anthony; Yonan, Charles

2016-07-01

Pseudobulbar affect (PBA) is a neurological disorder of emotional expression, characterized by uncontrollable episodes of crying or laughing in patients with certain neurological disorders affecting the brain. The purposes of this study were to estimate the prevalence of PBA in US nursing home residents and examine the relationship between PBA symptoms and other clinical correlates, including the use of psychopharmacological medications. A retrospective study was conducted between 2013 and 2014 with a convenience sample of residents from nine Michigan nursing homes. Chronic-care residents were included in the "predisposed population" if they had a neurological disorder affecting the brain and no evidence of psychosis, delirium, or disruptive behavior (per chart review). Residents were screened for PBA symptoms by a geropsychologist using the Center for Neurologic Study-Lability Scale (CNS-LS). Additional clinical information was collected using a diagnostic evaluation checklist and the most recent Minimum Data Set 3.0 assessment. Of 811 residents screened, complete data were available for 804, and 412 (51%) met the criteria for the "predisposed population." PBA symptom prevalence, based on having a CNS-LS score ≥13, was 17.5% in the predisposed population and 9.0% among all nursing home residents. Those with PBA symptoms were more likely to have a documented mood disorder and be using a psychopharmacological medication, including antipsychotics, than those without PBA symptoms. Pseudobulbar affect symptoms were present in 17.5% of nursing home residents with neurological conditions, and 9.0% of residents overall. Increasing awareness and improving diagnostic accuracy of PBA may help optimize treatment. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Prevalence of pseudobulbar affect symptoms and clinical correlates in nursing home residents

PubMed Central

Konetzka, R. Tamara; Bunin, Anthony; Yonan, Charles

2015-01-01

Objective Pseudobulbar affect (PBA) is a neurological disorder of emotional expression, characterized by uncontrollable episodes of crying or laughing in patients with certain neurological disorders affecting the brain. The purposes of this study were to estimate the prevalence of PBA in US nursing home residents and examine the relationship between PBA symptoms and other clinical correlates, including the use of psychopharmacological medications. Methods A retrospective study was conducted between 2013 and 2014 with a convenience sample of residents from nine Michigan nursing homes. Chronic‐care residents were included in the “predisposed population” if they had a neurological disorder affecting the brain and no evidence of psychosis, delirium, or disruptive behavior (per chart review). Residents were screened for PBA symptoms by a geropsychologist using the Center for Neurologic Study‐Lability Scale (CNS‐LS). Additional clinical information was collected using a diagnostic evaluation checklist and the most recent Minimum Data Set 3.0 assessment. Results Of 811 residents screened, complete data were available for 804, and 412 (51%) met the criteria for the “predisposed population.” PBA symptom prevalence, based on having a CNS‐LS score ≥13, was 17.5% in the predisposed population and 9.0% among all nursing home residents. Those with PBA symptoms were more likely to have a documented mood disorder and be using a psychopharmacological medication, including antipsychotics, than those without PBA symptoms. Conclusions Pseudobulbar affect symptoms were present in 17.5% of nursing home residents with neurological conditions, and 9.0% of residents overall. Increasing awareness and improving diagnostic accuracy of PBA may help optimize treatment. © 2015 The Authors. International Journal of Geriatric Psychiatry Published by John Wiley & Sons Ltd. PMID:26526856

What have positron emission tomography and 'Zippy' told us about the neuropharmacology of drug addiction?

PubMed

Cumming, Paul; Caprioli, Daniele; Dalley, Jeffrey W

2011-08-01

Translational molecular imaging with positron emission tomography (PET) and allied technologies offer unrivalled applications in the discovery of biomarkers and aetiological mechanisms relevant to human disease. Foremost among clinical PET findings during the past two decades of addiction research is the seminal discovery of reduced dopamine D(2/3) receptor expression in the striatum of drug addicts, which could indicate a predisposing factor and/or compensatory reaction to the chronic abuse of stimulant drugs. In parallel, recent years have witnessed significant improvements in the performance of small animal tomographs (microPET) and a refinement of animal models of addiction based on clinically relevant diagnostic criteria. This review surveys the utility of PET in the elucidation of neuropharmacological mechanisms underlying drug addiction. It considers the consequences of chronic drug exposure on regional brain metabolism and neurotransmitter function and identifies those areas where further research is needed, especially concerning the implementation of PET tracers targeting neurotransmitter systems other than dopamine, which increasingly have been implicated in the pathophysiology of drug addiction. In addition, this review considers the causal effects of behavioural traits such as impulsivity and novelty/sensation-seeking on the emergence of compulsive drug-taking. Previous research indicates that spontaneously high-impulsive rats--as exemplified by 'Zippy'--are pre-disposed to escalate intravenous cocaine self-administration, and subsequently to develop compulsive drug taking tendencies that endure despite concurrent adverse consequences of such behaviour, just as in human addiction. The discovery using microPET of pre-existing differences in dopamine D(2/3) receptor expression in the striatum of high-impulsive rats suggests a neural endophenotype that may likewise pre-dispose to stimulant addiction in humans. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Variation in Telangiectasia Predisposing Genes Is Associated With Overall Radiation Toxicity

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

Tanteles, George A.; Department of Cancer Studies and Molecular Medicine, University Hospitals of Leicester, Leicester Royal Infirmary, Leicester; Murray, Robert J.S.

2012-11-15

Purpose: In patients receiving radiotherapy for breast cancer where the heart is within the radiation field, cutaneous telangiectasiae could be a marker of potential radiation-induced heart disease. We hypothesized that single nucleotide polymorphisms (SNPs) in genes known to cause heritable telangiectasia-associated disorders could predispose to such late, normal tissue vascular damage. Methods and Materials: The relationship between cutaneous telangiectasia as a late normal tissue radiation injury phenotype in 633 breast cancer patients treated with radiotherapy was examined. Patients were clinically assessed for the presence of cutaneous telangiectasia and genotyped at nine SNPs in three candidate genes. Candidate SNPs were withinmore » the endoglin (ENG) and activin A receptor, type II-like 1 (ACVRL1) genes, mutations in which cause hereditary hemorrhagic telangiectasia and the ataxia-telangiectasia mutated (ATM) gene associated with ataxia-telangiectasia. Results: A total of 121 (19.1%) patients exhibited a degree of cutaneous telangiectasiae on clinical examination. Regression was used to examine the associations between the presence of telangiectasiae in patients who underwent breast-conserving surgery, controlling for the effects of boost and known brassiere size (n=388), and individual geno- or haplotypes. Inheritance of ACVRL1 SNPs marginally contributed to the risk of cutaneous telangiectasiae. Haplotypic analysis revealed a stronger association between inheritance of a ATM haplotype and the presence of cutaneous telangiectasiae, fibrosis and overall toxicity. No significant association was observed between telangiectasiae and the coinheritance of the candidate ENG SNPs. Conclusions: Genetic variation in the ATM gene influences reaction to radiotherapy through both vascular damage and increased fibrosis. The predisposing variation in the ATM gene will need to be better defined to optimize it as a predictive marker for assessing radiotherapy late effects.« less

Prevalence of high altitude pulmonary hypertension among the natives of Spiti Valley--a high altitude region in Himachal Pradesh, India.

PubMed

Negi, Prakash Chand; Marwaha, Rajeev; Asotra, Sanjeev; Kandoria, Arvind; Ganju, Neeraj; Sharma, Rajesh; Kumar, Ravi V; Bhardwaj, Rajeev

2014-12-01

The study aimed to determine the prevalence of high altitude pulmonary hypertension (HAPH) and its predisposing factors among natives of Spiti Valley. A cross-sectional survey study was done on the permanent natives of Spiti Valley residing at an altitude of 3000 m to 4200 m. Demographic characteristics, health behavior, anthropometrics, and blood pressure were recorded. Investigations included recording of 12 lead electrocardiogram (ECG), SaO2 with pulse oximeter, spirometry and echocardiography study, and measurement of Hb levels using the cynmethhemoglobin method. HAPH was diagnosed using criteria; tricuspid regurgitation (TR) gradient of ≥46 mmHg. ECG evidence of RV overload on 12 lead ECG was documented based on presence of 2 out of 3 criteria; R>S in V1, right axis deviation or RV strain, T wave inversion in V1 and V2. Data of 1087 subjects were analyzed who were free of cardiorespiratory diseases to determine the prevalence of HAPH and its predisposing factors. HAPH was recorded in 3.23% (95% C.I. of 0.9-8.1%) and ECG evidence of right ventricular (RV) overload was 1.5% in the study population. Prevalence of HAPH was not different in men and women 2.63% vs. 3.54% p<0.2. Age (Z statistics of 3.4 p<0.0006), hypoxemia (Z statistics of 2.9 p<0.002), and erythrocythemia (Z statistics of 4.7 p<0.003) were independently associated with HAPH. Altitude of residence was not found to be significantly associated with HAPH, although there was a trend of increasing prevalence with increasing altitude. It can be concluded that HAPH is prevalent in 3.23% of natives of Spiti Valley. Increasing age, erythrocythemia and hypoxemia are independent predisposing factors.

Vitamin C and E chronic supplementation differentially affect hepatic insulin signaling in rats.

PubMed

Ali, Mennatallah A; Eid, Rania M H M; Hanafi, Mervat Y

2018-02-01

Vitamin C and vitamin E supplementations and their beneficial effects on type 2 diabetes mellitus (T2DM) have been subjected to countless controversial data. Hence, our aim is to investigate the hepatic molecular mechanisms of any diabetic predisposing risk of the chronic administration of different doses of vitamin E or vitamin C in rats. The rats were supplemented with different doses of vitamin C or vitamin E for eight months. Vitamin C and vitamin E increased fasting blood glucose, insulin, and homeostasis model assessment index for insulin resistance (HOMA). Vitamin C disrupted glucose tolerance by attenuating upstream hepatic insulin action through impairing the phosphorylation and activation of insulin receptor and its subsequent substrates; however, vitamin E showed its effect downstream insulin receptor in the insulin signaling pathway, reducing hepatic glucose transporter-2 (GLUT2) and phosphorylated protein kinase (p-Akt). Moreover, both vitamins showed their antioxidant capabilities [nuclear factor-erythroid-2-related factor 2 (Nrf2), total and reduced glutathione] and their negative effect on Wnt pathway [phosphorylated glycogen synthase kinase-3β (p-GSK-3β)], by altering the previously mentioned parameters, inevitably leading to severe reduction of reactive oxygen species (ROS) below the physiological levels. In conclusion, a detrimental effect of chronic antioxidant vitamins supplementation was detected; leading to insulin resistance and impaired glucose tolerance obviously through different mechanisms. Overall, these findings indicate that the conventional view that vitamins promote health benefits and delay chronic illnesses and aging should be modified or applied with caution. Copyright © 2017. Published by Elsevier Inc.

Ubiquitin ligase gp78 increases solubility and facilitates degradation of the Z variant of {alpha}-1-antitrypsin

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

Shen Yuxian; Medical Biotechnology Center, University of Maryland Biotechnology Institute, Baltimore, MD; Ballar, Petek

2006-11-03

Deficiency of circulating {alpha}-1-antitrypsin (AAT) is the most widely recognized abnormality of a proteinase inhibitor that causes lung disease. AAT-deficiency is caused by mutations of the AAT gene that lead to AAT protein retention in the endoplasmic reticulum (ER). Moreover, the mutant AAT accumulated in the ER predisposes the homozygote to severe liver injuries, such as neonatal hepatitis, juvenile cirrhosis, and hepatocellular carcinoma. Despite the fact that mutant AAT protein is subject to ER-associated degradation (ERAD), yeast genetic studies have determined that the ubiquitination machinery, Hrd1/Der3p-cue1p-Ubc7/6p, which plays a prominent role in ERAD, is not involved in degradation of mutantmore » AAT. Here we report that gp78, a ubiquitin ligase (E3) pairing with mammalian Ubc7 for ERAD, ubiquitinates and facilitates degradation of ATZ, the classic deficiency variant of AAT having a Z mutation (Glu 342 Lys). Unexpectedly, gp78 over-expression also significantly increases ATZ solubility. p97/VCP, an AAA ATPase essential for retrotranslocation of misfolded proteins from the ER during ERAD, is involved in gp78-mediated degradation of ATZ. Surprisingly, unlike other ERAD substrates that cause ER stress leading to apoptosis when accumulated in the ER, ATZ, in fact, increases cell proliferation when over-expressed in cells. This effect can be partially inhibited by gp78 over-expression. These data indicate that gp78 assumes multiple unique quality control roles over ATZ, including the facilitation of degradation and inhibition of aggregation of ATZ.« less

Sex Differences in the Biology and Pathology of the Aging Heart.

PubMed

Keller, Kaitlyn M; Howlett, Susan E

2016-09-01

The knowledge that advanced age is a major risk factor for cardiovascular disease (CVD) has stimulated interest in cardiac aging. Understanding how the heart remodels with age can help us appreciate why older individuals are more likely to acquire heart disease. Growing evidence in both humans and animals shows that the heart exhibits distinct structural and functional changes as a consequence of age. These changes occur even in the absence of overt cardiovascular disease and are often maladaptive. For example, atrial hypertrophy and fibrosis may increase susceptibility to atrial fibrillation in older adults. Age-dependent increases in left ventricular fibrosis, stiffness, and wall thickness promote diastolic dysfunction, predisposing to heart failure with preserved ejection fraction. The influence of age on the heart is evident at rest but is even more prominent during exercise. There is also evidence for sex-specific variation in age-associated remodelling. For instance, there is some evidence that the number of ventricular myocytes declines with age through apoptosis in men but not in women. This helps explain why older men are more likely than women to experience heart failure with reduced ejection fraction. Emerging evidence from preclinical studies suggests that frailty rather than chronological age promotes adverse cardiac remodelling. Mechanisms implicated in cardiac aging include impaired calcium handling, excessive activation of the ß-adrenergic and renin-angiotensin systems, and mitochondrial dysfunction. Further research into cardiac aging in both sexes is needed, because it may be possible to modify disease treatment if the substrate upon which the disease first develops is better understood. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

The role of monoamine oxidase A in aggression: current translational developments and future challenges

PubMed Central

Godar, Sean C; Fite, Paula J; McFarlin, Kenneth M; Bortolato, Marco

2016-01-01

Drawing upon the recent resurgence of biological criminology, several studies have highlighted a critical role for genetic factors in the ontogeny of antisocial and violent conduct. In particular, converging lines of evidence have documented that these maladaptive manifestations of aggression are influenced by monoamine oxidase A (MAOA), the enzyme that catalyzes the degradation of brain serotonin, norepinephrine and dopamine. The interest on the link between MAOA and aggression was originally sparked by Han Brunner’s discovery of a syndrome characterized by marked antisocial behaviors in male carriers of a nonsense mutation of this gene. Subsequent studies showed that MAOA allelic variants associated with low enzyme activity moderate the impact of early-life maltreatment on aggression propensity. In spite of overwhelming evidence pointing to the relationship between MAOA and aggression, the neurobiological substrates of this link remain surprisingly elusive; very little is also known about the interventions that may reduce the severity of pathological aggression in genetically predisposed subjects. Animal models offer a unique experimental tool to investigate these issues; in particular, several lines of transgenic mice harboring total or partial loss-of-function Maoa mutations have been shown to recapitulate numerous psychological and neurofunctional endophenotypes observed in humans. This review summarizes the current knowledge on the link between MAOA and aggression; in particular, we will emphasize how an integrated translational strategy coordinating clinical and preclinical research may prove critical to elucidate important aspects of the pathophysiology of aggression, and identify potential targets for its diagnosis, prevention and treatment. PMID:26776902