Influence of charge on filtration across renal basement membrane films in vitro

AbstractInfluence of charge on filtration across renal basement membrane films in vitro. The filtration of differently charged species of myoglobin and dextran across films of isolated basement membrane in vitro showed that the filtration behavior of both polymers was influenced by charge. Rejection increased with increasing negative charge. Titration of the isolated basement membrane revealed an isoionic point of pH 5.5 and an isoelectric point of pH 5.7. The net negative charge at pH 7.4 was 0.15 mEq/g protein; this charge was attributed to carboxylate anion. Glycosaminoglycan sulphate did not contribute significantly to the net charge. Filtration of narrow range dextran fractions across films of basement membrane at the isoelectric point markedly reduced differences in filtration due to charge confirming that the differences in behavior found at pH 7.4 were due to charge interactions between the solutes and the membranes. Physical characterization of the charged and uncharged dextran fractions revealed no substantial differences in size or shape for the differently charged species.Influence de la charge sur la filtration à travers des films de membrane basale rénale in vitro. La filtration d'espèces différemment chargées de myoglobine et de dextran à travers des films de membrane basale isolée in vitro a montré que le comportement de filtration des deux polymères était influencé par la charge. Le rejet s'élevait lorsque la charge négative augmentait. La titration de la membrane basale isolée a révélé un point isoionique de pH 5,5 et un point isoélectrique de pH 5,7. La charge négative nette à pH 7,4 était de 0,15 mEq/g protéines; cette charge a été attribuée à l'anion carboxylate. Le sulfate de glycosaminoglycan ne contribuait pas significativement à la charge nette. La filtration de fractions d'étendues étroites de dextran à travers des films de membrane basale au point isoélectrique réduisait de façon marquée les différences de filtration dûes à la charge, confirmant que ses différences de comportement trouvées à pH 7,4 étaient dûes à des interactions de charge entre les solutes et les membranes. La caratérisation physique des fractions de dextran chargées ou non n'a pas révélé de différence substantielle dans la taille ou la forme des espèces de charges différentes

Plant Macrofossils Associated with an Early Holocene Beaver Dam in Interior Alaska

Dynamic climate changes and expansion of new biomes characterize the late Pleistocene–early Holocene of eastern Beringia. Analysis of plant macrofossils from an early Holocene (ca. 9300 14C yrs BP) beaver dam in central Alaska provides insight into the local environment and vegetation. The plant macrofossil assemblage comprises remains of trees and shrubs, graminoids, and forbs, including Betula sp., Carex sp., Rubus sp., Eleocharis sp., Scirpus sp., Potamogeton sp., Najas flexilis and Typha latifolia, indicative of standing water of a beaver pond. Bryophytes from the beaver dam include Warnstorfia spp. and Drepanocladus aduncus, suggesting shallow, stagnant, or slow-moving water. The presence of Najas flexilis, Typha latifolia, and modern beaver (Castor canadensis) suggest that central Alaska had a warmer climate during the early Holocene.Changements climatiques dynamiques et expansion de nouveaux biomes caractérisent la période du Pléistocène supérieur et de l’Holocène inférieur de la Béringie de l’Est. L’analyse des macrofossiles de plantes provenant d’une digue de castor du centre de l’Alaska datant de l’Holocène inférieur (env. 9300 14C années BP) donne des indices sur l’environnement et la végétation de la région. L’assemblage de macrofossiles de plantes est composé d’arbres et d’arbustes, de graminoïdes et d’herbes non graminéennes, dont Betula sp., Carex sp., Rubus sp., Eleocharis sp., Scirpus sp., Potamogeton sp., Najas flexilis et Typha latifolia, ce qui signale la présence d’eau stagnante dans un étang de castor. Parmi les bryophytes de la digue de castor, notons Warnstorfia spp. et Drepanocladus aduncus, ce qui laisse supposer la présence d’eau peu profonde stagnante ou se déplaçant lentement. Par ailleurs, la présence de Najas flexilis, Typha latifolia et du castor contemporain (Castor canadensis) laissent croire que le climat du centre de l’Alaska était plus chaud pendant l’Holocène inférieur

Ethical Issues Surrounding Weight Bias and Stigma in Healthcare

With the recognition of obesity as a global epidemic (World Health Organization [WHO], 2012), there has been increased interest in the study of weight bias and stigmatization (Ashmore, Friedman, Reichmann, & Musante, 2008; Puhl, Schwartz, & Brownell, 2005). Weight bias is a highly prevalent form of discrimination, perhaps as common as racial bias (Shkolnikova, 2008). Occurring in a wide variety of settings, weight bias may produce adverse effects in social relationships, education, employment, and health care (Durso & Latner, 2008), with the result that obese or overweight persons are socially marginalized and stigmatized

Dorsal Raphe Dopamine Neurons Modulate Arousal and Promote Wakefulness by Salient Stimuli

Ventral midbrain dopamine (DA) is unambiguously involved in motivation and behavioral arousal, yet the contributions of other DA populations to these processes are poorly understood. Here, we demonstrate that the dorsal raphe nucleus DA neurons are critical modulators of behavioral arousal and sleep-wake patterning. Using simultaneous fiber photometry and polysomnography, we observed time-delineated dorsal raphe nucleus dopaminergic (DRNDA) activity upon exposure to arousal-evoking salient cues, irrespective of their hedonic valence. We also observed broader fluctuations of DRNDA activity across sleep-wake cycles with highest activity during wakefulness. Both endogenous DRNDA activity and optogenetically driven DRNDA activity were associated with waking from sleep, with DA signal strength predictive of wake duration. Conversely, chemogenetic inhibition opposed wakefulness and promoted NREM sleep, even in the face of salient stimuli. Therefore, the DRNDA population is a critical contributor to wake-promoting pathways and is capable of modulating sleep-wake states according to the outside environment, wherein the perception of salient stimuli prompts vigilance and arousal

County-level hurricane exposure and birth rates: application of difference-in-differences analysis for confounding control

Abstract Background Epidemiological analyses of aggregated data are often used to evaluate theoretical health effects of natural disasters. Such analyses are susceptible to confounding by unmeasured differences between the exposed and unexposed populations. To demonstrate the difference-in-difference method our population included all recorded Florida live births that reached 20 weeks gestation and conceived after the first hurricane of 2004 or in 2003 (when no hurricanes made landfall). Hurricane exposure was categorized using ≥74 mile per hour hurricane wind speed as well as a 60 km spatial buffer based on weather data from the National Oceanic and Atmospheric Administration. The effect of exposure was quantified as live birth rate differences and 95 % confidence intervals [RD (95 % CI)]. To illustrate sensitivity of the results, the difference-in-differences estimates were compared to general linear models adjusted for census-level covariates. This analysis demonstrates difference-in-differences as a method to control for time-invariant confounders investigating hurricane exposure on live birth rates. Results Difference-in-differences analysis yielded consistently null associations across exposure metrics and hurricanes for the post hurricane rate difference between exposed and unexposed areas (e.g., Hurricane Ivan for 60 km spatial buffer [−0.02 births/1000 individuals (−0.51, 0.47)]. In contrast, general linear models suggested a positive association between hurricane exposure and birth rate [Hurricane Ivan for 60 km spatial buffer (2.80 births/1000 individuals (1.94, 3.67)] but not all models. Conclusions Ecological studies of associations between environmental exposures and health are susceptible to confounding due to unmeasured population attributes. Here we demonstrate an accessible method of control for time-invariant confounders for future research

The fifth adaptor protein complex.

Adaptor protein (AP) complexes sort cargo into vesicles for transport from one membrane compartment of the cell to another. Four distinct AP complexes have been identified, which are present in most eukaryotes. We report the existence of a fifth AP complex, AP-5. Tagged AP-5 localises to a late endosomal compartment in HeLa cells. AP-5 does not associate with clathrin and is insensitive to brefeldin A. Knocking down AP-5 subunits interferes with the trafficking of the cation-independent mannose 6-phosphate receptor and causes the cell to form swollen endosomal structures with emanating tubules. AP-5 subunits can be found in all five eukaryotic supergroups, but they have been co-ordinately lost in many organisms. Concatenated phylogenetic analysis provides robust resolution, for the first time, into the evolutionary order of emergence of the adaptor subunit families, showing AP-3 as the basal complex, followed by AP-5, AP-4, and AP-1 and AP-2. Thus, AP-5 is an evolutionarily ancient complex, which is involved in endosomal sorting, and which has links with hereditary spastic paraplegia

Women's Advocates Shelter: An Evaluation.

Prepared by the School of Architecture and Center for Urban and Regional Affairs, University of Minnesota, for the Minnesota Housing Finance Agency