a b s t r a c tBackground: Although there is substantial evidence of differential hypothalamic-pituitary-adrenal (HPA) axis activity in both generalized and abdominal obesity, consistent trends in obesity-related HPA axis perturbations have yet to be identified. Objectives: To systematically review the existing literature on HPA activity in obesity, identify possible explanations for inconsistencies in the literature, and suggest methodological improvements for future study. Data sources: Included papers used Pubmed, Google Scholar, and the University of California Library search engines with search terms body mass index (BMI), waist-to-hip ratio (WHR), waist circumference, sagittal diameter, abdominal versus peripheral body fat distribution, body fat percentage, DEXA, abdominal obesity, and cortisol with terms awakening response, slope, total daily output, reactivity, feedback sensitivity, long-term output, and 11␤-HSD expression. Study eligibility criteria: Empirical research papers were eligible provided that they included at least one type of obesity (general or abdominal), measured at least one relevant cortisol parameter, and a priori tested for a relationship between obesity and cortisol. Results: A general pattern of findings emerged where greater abdominal fat is associated with greater responsivity of the HPA axis, reflected in morning awakening and acute stress reactivity, but some studies did show underresponsiveness. When examined in adipocytes, there is a clear upregulation of cortisol output (due to greater expression of 11␤-HSD1), but in hepatic tissue this cortisol is downregulated. Overall obesity (BMI) appears to also be related to a hyperresponsive HPA axis in many but not all studies, such as when acute reactivity is examined. Limitations: The reviewed literature contains numerous inconsistencies and contradictions in research methodologies, sample characteristics, and results, which partially precluded the development of clear and reliable patterns of dysregulation in each investigated cortisol parameter. Conclusions and implications:The literature to date is inconclusive, which may well arise from differential effects of generalized obesity vs. abdominal obesity or from modulators such as sex, sex hormones, and chronic stress. While the relationship between obesity and adipocyte cortisol seems to be clear, further research is warranted to understand how adipocyte cortisol metabolism influences circulating cortisol levels and to establish consistent patterns of perturbations in adrenal cortisol activity in both generalized and abdominal obesity.

Severity of wildfires is a critical component of the fire regime and plays an important role in determining forest ecosystem response to fire disturbance. Predicting spatial distribution of potential fire severity can be valuable in guiding fire and fuel management planning. Spatial controls on fire severity patterns have attracted growing interest, but few studies have attempted to predict potential fire severity in fire-prone Eurasian boreal forests. Furthermore, the influences of fire weather variation on spatial heterogeneity of fire severity remain poorly understood at fine scales. We assessed the relative importance and influence of pre-fire vegetation, topography, and surface moisture availability (SMA) on fire severity in 21 lightning-ignited fires occurring in two different fire years (3 fires in 2000, 18 fires in 2010) of the Great Xing'an Mountains with an ensemble modeling approach of boosted regression tree (BRT). SMA was derived from 8-day moderate resolution imaging spectroradiometer (MODIS) evapotranspiration products. We predicted the potential distribution of fire severity in two fire years and evaluated the prediction accuracies. BRT modeling revealed that vegetation, topography, and SMA explained more than 70% of variations in fire severity (mean 83.0% for 2000, mean 73.8% for 2010). Our analysis showed that evergreen coniferous forests were more likely to experience higher severity fires than the dominant deciduous larch forests of this region, and deciduous broadleaf forests and shrublands usually burned at a significantly lower fire severity. High-severity fires tended to occur in gentle and well-drained slopes at high altitudes, especially those with north-facing aspects. SMA exhibited notable and consistent negative association with severity. Predicted fire severity from our model exhibited strong agreement with the observed fire severity (mean r 2 = 0.795 for 2000, 0.618 for 2010). Our results verified that spatial variation of fire severity within a burned patch is predictable at the landscape scale, and the prediction of potential fire severity could be improved by incorporating remotely sensed biophysical variables related to weather conditions.

The general problem of this experiment was to compare the electrical resistance of the subject during relaxation with his resistance during bodily tension. The electrical resistance of the human body has been studied by many investigators under various conditions. It has been studied with reference to the activity of the sweat glands by Darrow (i), Einthoven and Roos (3), Georgi (4), Markbreiter (6), Waller (11), and Wells and Forbes ( 14). It has been studied with reference to circulation by Jung (5), Sidis and Nelson (9), and Waller (11). Ebbecke (2), Feri (5), Jung (5), Darrow (1), Priedeaux (10), Sidis and Kalmus (8), Tarchanoff (5), and Veraguth (5) have studied it with reference to mechanical, chemical, and electrical stimulations. No one, so far as the writer has been able to ascertain, has made any thoroughgoing investigation of the relation existing between bodily tension and electrical resistance. This relationship should not be neglected, for if it is discovered that the electrical resistance does vary with bodily tension, it will be necessary to take this fact into consideration in performing experiments with the galvanic reflex and in interpreting the experiments hitherto performed. APPARATUSThe electrodes used in this experiment were made of zinc, and were about two centimeters long and a centimeter wide. These electrodes were covered with kaolin paste and an extremely weak solution of zinc sulphate. In the various series the electrodes were attached to different portions of 1 From the Psychological Laboratory of the University of Chicago. I am indebted to Dr. C. W. Darrow for aid in this experiment.

Over 2 decades ago, social psychological research revealed that weight stigma may undermine educational achievement. This study documented that a greater proportion of college students were thin compared with the general population and that heavier females received less college financial support from parents than thinner females (Crandall, 1995). Although frequently cited, there is no current literature on these phenomena despite major changes since the 1990s including a much higher prevalence of obesity and the economic downturn known as the "Great Recession." Thus, in the interest of pursuing replicable science, the present study examined the role of weight stigma in higher education in 2 studies using ethnically diverse samples of first-year college students. We found that the average Body Mass Index (BMI) and BMI distribution in our samples were still significantly lower than a nationally representative sample, regardless of gender and ethnicity. We also found that, among females, self-funded students had higher BMIs than parent-funded students. In one sample, this was also the case for males. Together these findings suggest that not only are heavy young adults perhaps less likely to be in college than their thin counterparts, but they may also receive less support from their parents. This points to the possibility that weight stigma may undermine educational achievement in today's youth, which could have negative downstream consequences for lifelong socioeconomic, health, and well-being outcomes.

Boreal forests store a large proportion of the global terrestrial carbon (C), while wildfire plays a crucial role in determining their C storage and dynamics. The aboveground C (AC) pool is an important component of forest C stocks. To quantify the turning point (transforming from C source to C sink) and recovery time of postfire AC, and assess how stand density affects the AC, 175 plots from eight stand age classes were surveyed as a chronosequence in the Great Xing'an Mountains of Northeast China. Linear and nonlinear regression analyses were conducted to describe postfire AC recovery patterns. The results showed that (1) postfire AC exhibited a skewed U-shaped pattern with the turning point at approximately year 30, when the change rate of AC shifted from negative to positive, (2) it took more than 120 years for this forest ecosystem to recover 80% of AC in unburned old-growth (200 years) stands, and (3) there was an overall positive relationship between AC and stand density over the entire range of stand age classes; and such relationship was stronger during the early-and late-successional stages, but weaker (p > 0.05) during the midsuccessional stage. Although boreal larch forests have been C sinks under historical fire free intervals, predicted increases in fire frequency could potentially shift it to a C source. Understanding postfire AC dynamics in boreal larch forests is central to predicting C cycling response to wildfire and provides a framework for assessing ecosystem resilience to disturbance in this region. Plain Language SummaryBoreal forests store more than 32% of total global forest carbon (C), but this C pool is very susceptible to wildfires which are one of the most pervasive disturbances in the boreal biome. Identifying the dynamic trajectory and recovery pattern of postfire aboveground C (AC) storage is crucial for understanding the global ecological significance of wildfire disturbance. A total of 175 plots from eight stand age classes were surveyed in the Great Xing'an Mountains of Northeast China to quantify ecological resilience, and further examine the relationship between various components of AC and stand density throughout successional stages. Our data analysis showed that the AC pool could be a C source to the atmosphere for several decades following fire disturbances; and it would take more than a century for the AC to recover 80% of that in old-growth boreal larch forests in Northeastern China. Increases in fire frequency due to climate change and human activities will increase C emission, which may significantly influence the regional C budget. Stand density was considered as a positive factor on AC accumulation following wildfire, but this effect may be counteracted by variation in tree size due to site productivity in other successional stages. Key Points:• Postfire dynamics of aboveground carbon storage were depicted over a 200-year chronosequence in boreal larch forests • Aboveground carbon transformed from a source to a sink after 30 years, and it took over 120 years to recov...

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Studies have shown that the spatial distribution of severe thunderstorm warnings demonstrates variation beyond what can be attributed to weather and climate alone. Investigating spatial patterns of these variations can provide insight into nonmeteorological factors that might lead forecasters to issue warnings. Geographically weighted regression was performed on a set of demographic and land cover descriptors to ascertain their relationships with National Weather Service (NWS) severe thunderstorm warning polygons issued by 36 NWS forecast offices in the central and southeastern United States from 2008 to 2015. County warning area (CWA) boundaries and cities were predominant sources of variability in warning counts. Global explained variance in verified and unverified severe thunderstorm warnings ranged from 67% to 81% for population, median income, and percent imperviousness across the study area, which supports the spatial influence of these variables on warning issuance. Local regression coefficients indicated that verified and unverified warning counts increased disproportionately in larger cities relative to the global trend, particularly for NWS weather forecast office locations. However, local explained variance tended to be lower in cities, possibly due to greater complexity of social and economic factors shaping warning issuance. Impacts of thunderstorm type and anthropogenic modification of existing storms should also be considered when interpreting the results of this study.