HIV disclosure has been considered key to prevention and privileged as a “healthy” behavior for people living with HIV. Although research has documented potential negative outcomes of disclosure, we ...know little about its potential of these consequences to disrupt one's biography, or the intersectional and structural inequities that shape disclosure/nondisclosure and its outcomes. Exploring HIV disclosure as a discrete, measurable event cannot account for the experience of the self in illness, and how disclosure can fundamentally shift everyday reality and social relationships. To fill this gap, I employed the framework of structural intersectionality, and the medical sociology theory of biographical disruption to explore HIV disclosure among a sample of Black gay and bisexual men living with HIV in the Deep South. Between June 2019 and June 2020, I conducted in-depth qualitative interviews with 30 Black gay and bisexual men living with HIV in the Baton Rouge, Louisiana metropolitan area. Interviews were recorded and transcribed verbatim and analyzed using a grounded theory approach. Disruptions as a result of HIV disclosure included: assaults on self; disturbance to social and familial networks; and socioeconomic impacts. Further, findings illustrate that disruptions were not discrete events, but evolved over time, and that the nature of disruption was constituted by previous traumatic disruptions, social and structural contexts, and men's social location at the intersections of race, class, sexuality, HIV-status, and geography. I highlight that consequences of HIV disclosure among a sample of Black gay and bisexual men, were shaped by their unique social location and the persistence of intersecting structural inequities. Future research should account for preceding and cumulative experiences, how intersecting inequities constitute disclosure experiences, and that disclosure is a complex process occurring in the context of ongoing social relations.
•Black gay and bisexual men exist at the intersections of multiple axes of structural oppression.•HIV disclosure is an ongoing and evolving process occurring within ongoing social relations.•HIV disclosure interventions must account for preceding and cumulative experiences.•HIV disclosure outcomes are complex, nuanced, and shaped by social location.
In the United States, Black gay and bisexual men account for a quarter of HIV infections and face intersecting social and structural stigmas along the axes of race, sexuality and class. For those ...diagnosed with HIV, these inequities shape their lived experiences which include HIV disclosure. Public health has privileged HIV status disclosure as the appropriate moral and responsible choice to protect sex partners, reduce stigma and obtain social support. Though little is known about the emotional aspects of HIV disclosure for Black gay and bisexual men, or how they are shaped by social and structural contexts. Using the frameworks of healthism and emotion work, I explore HIV disclosure among a sample of 30 Black gay and bisexual men living with HIV in the Deep South. Drawing on in‐depth, qualitative interviews, I identify the emotion work that men engaged in to manage their own emotions and protect the emotions of others before, during and after disclosure or nondisclosure. These findings challenge public health research that has explored disclosure as discrete measurable events by illustrating how HIV disclosure is embedded in ongoing social and structural relations and provide insights that can guide new approaches focused on structural inequities that constitute HIV disclosure.
Understanding the drivers of nutrient distributions across heterogeneous tropical landscapes, and the implication of those distributions for ecosystem processes, remains a challenge in ...biogeochemistry. Guided by a high-resolution digital elevation model, we determined soil chemical characteristics, including rock-derived nutrient availability and total element concentrations, along 16 hillslopes with two different morphologies on a terra firme landscape in the lowland Peruvian Amazon. We assessed the role of geomorphic processes in rejuvenating soils, and the role of biotic processes in retaining nutrients in surface soils along toposequences. Our results show that the chemical weathering state of subsurface soils decreases down convex slopes, suggesting a role for erosion-driven rejuvenation. Total phosphorus (P) and calcium (Ca) are less depleted in surface soils than subsurface soils, in contrast to the vertical patterns observed for total magnesium (Mg) and potassium (K). Exchangeable Ca and Mg are highly concentrated in surface soils relative to the total available in the top meter of soil, which remains true as the total amount of these nutrients available in the top meter of soil increases along convex hillslopes. The combined results suggest that Ca is especially tightly cycled by this tropical forest ecosystem, and that steep, eroding hillslopes play a major role in the distribution and rejuvenation of rock-derived nutrients in regions far from marine aerosol and dust inputs. Geomorphically-mediated distributions of these nutrients, in turn, may underpin spatial variation in tropical forest carbon dynamics.
Airborne high fidelity imaging spectroscopy (HiFIS) holds great promise for bridging the gap between field studies of functional diversity, which are spatially limited, and satellite detection of ...ecosystem properties, which lacks resolution to understand within landscape dynamics. We use Carnegie Airborne Observatory HiFIS data combined with field collected foliar trait data to develop quantitative prediction models of foliar traits at the tree-crown level across over 1000 ha of humid tropical forest. We predicted foliar leaf mass per area (LMA) as well as foliar concentrations of nitrogen, phosphorus, calcium, magnesium and potassium for canopy emergent trees (R2: 0.45–0.67, relative RMSE: 11%–14%). Correlations between remotely sensed model coefficients for these foliar traits are similar to those found in laboratory studies, suggesting that the detection of these mineral nutrients is possible through their biochemical stoichiometry. Maps derived from HiFIS provide quantitative foliar trait information across a tropical forest landscape at fine spatial resolution, and along environmental gradients. Multi-nutrient maps implemented at the fine organismic scale will subsequently provide new insight to the functional biogeography and biological diversity of tropical forest ecosystems.
Spatial information on forest functional composition is needed to inform management and conservation efforts, yet this information is lacking, particularly in tropical regions. Canopy foliar traits ...underpin the functional biodiversity of forests, and have been shown to be remotely measurable using airborne 350–2510 nm imaging spectrometers. We used newly acquired imaging spectroscopy data constrained with concurrent light detection and ranging (LiDAR) measurements from the Carnegie Airborne Observatory (CAO), and field measurements, to test the performance of the Spectranomics approach for foliar trait retrieval. The method was previously developed in Neotropical forests, and was tested here in the humid tropical forests of Malaysian Borneo. Multiple foliar chemical traits, as well as leaf mass per area (LMA), were estimated with demonstrable precision and accuracy. The results were similar to those observed for Neotropical forests, suggesting a more general use of the Spectranomics approach for mapping canopy traits in tropical forests. Future mapping studies using this approach can advance scientific investigations and applications based on imaging spectroscopy.
HIV stigma negatively affects the social experiences of people living with HIV (PLWH) and remains a challenge to HIV prevention, treatment, and care. Research has overwhelmingly focused on individual ...cognitive measures of HIV stigma (e.g., internalized, anticipated, and experienced). However, little research explores the interactions and societal structures through which HIV stigma is produced. Data from qualitative interviews with 30 black gay and bisexual men living with HIV in the U.S. Deep South revealed an interconnected and interdependent set of processes that produce and reproduce HIV stigma. These included social interactions (silence, euphemism, and gossip), witnessed acts of marginalization, word-of-mouth transmission of HIV misinformation, and laws and policies carried out within the education and criminal justice systems. Efforts to reduce stigma that focus on individual beliefs and attitudes are critical to improving the well-being of PLWH. However, reducing HIV stigma requires intervening on the social interactions and structures through which HIV stigma is produced and reproduced.
Accurate and spatially-explicit maps of tropical forest carbon stocks are needed to implement carbon offset mechanisms such as REDD+ (Reduced Deforestation and Degradation Plus). The Random Forest ...machine learning algorithm may aid carbon mapping applications using remotely-sensed data. However, Random Forest has never been compared to traditional and potentially more reliable techniques such as regionally stratified sampling and upscaling, and it has rarely been employed with spatial data. Here, we evaluated the performance of Random Forest in upscaling airborne LiDAR (Light Detection and Ranging)-based carbon estimates compared to the stratification approach over a 16-million hectare focal area of the Western Amazon. We considered two runs of Random Forest, both with and without spatial contextual modeling by including--in the latter case--x, and y position directly in the model. In each case, we set aside 8 million hectares (i.e., half of the focal area) for validation; this rigorous test of Random Forest went above and beyond the internal validation normally compiled by the algorithm (i.e., called "out-of-bag"), which proved insufficient for this spatial application. In this heterogeneous region of Northern Peru, the model with spatial context was the best preforming run of Random Forest, and explained 59% of LiDAR-based carbon estimates within the validation area, compared to 37% for stratification or 43% by Random Forest without spatial context. With the 60% improvement in explained variation, RMSE against validation LiDAR samples improved from 33 to 26 Mg C ha(-1) when using Random Forest with spatial context. Our results suggest that spatial context should be considered when using Random Forest, and that doing so may result in substantially improved carbon stock modeling for purposes of climate change mitigation.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The article is concerned with the radioprotection of a substantial radiosensitive population who present with cancer in early adulthood and will probably be treated with radiotherapy. A theory of ...radiation-induced health effects based on the induction of DNA double strand breaks is used to associate the radio-sensitivity of carriers of the BRCA1 and BRCA2 genes and the PALB2 gene with the defects in the homologous recombination repair of DNA damage found in the carriers. It is concluded that the defects in homologous recombination repair in these carriers will lead to an increased level of somatic mutations in all their cells and that this increased level of somatic mutations throughout their lifetime is, essentially, the reason that the carriers develop early onset cancer. This is a direct consequence of the more rapid accumulation of the cancer-inducing somatic mutations than the normal, slower accumulation in non-carriers. The radiotherapeutic treatment of these carriers needs to proceed with some care, taking account of their increased radio-sensitivity, and this suggests a need for international recognition and guidance of their radioprotection within the medical profession.
In the past several decades, field studies have shown that woody plants can access substantial volumes of water from the pores and fractures of bedrock1-3. If, like soil moisture, bedrock water ...storage serves as an important source of plant-available water, then conceptual paradigms regarding water and carbon cycling may need to be revised to incorporate bedrock properties and processes4-6. Here we present a lowerbound estimate of the contribution of bedrock water storage to transpiration across the continental United States using distributed, publicly available datasets. Temporal and spatial patterns of bedrock water use across the continental United States indicate that woody plants extensively access bedrock water for transpiration. Plants across diverse climates and biomes access bedrock water routinely and not just during extreme drought conditions. On an annual basis in California, the volumes of bedrock water transpiration exceed the volumes of water stored in human-made reservoirs, and woody vegetation that accesses bedrock water accounts for over 50% of the aboveground carbon stocks in the state. Our findings indicate that plants commonly access rock moisture, as opposed to groundwater, from bedrock and that, like soil moisture, rock moisture is a critical component of terrestrial water and carbon cycling.
More than 30 years into the HIV epidemic, men who have sex with men (MSM) continue to be disproportionately impacted. It is estimated that worldwide nearly half of MSM infected with HIV are unaware ...of their status, making HIV testing along with early linkage to care crucial to HIV prevention efforts. However, there remain significant barriers to HIV testing among MSM, due largely to complex issues of layered stigma that deter MSM from accessing traditional, clinic-based testing. We conducted a review and synthesis of the literature on strategies to increase uptake of HIV testing among MSM. We found that social network-based strategies, community-based testing, HIV self-testing, and modifications to the traditional clinic-based model can effectively reach a subset of MSM, but success was often context-specific and there are significant gaps in evidence. We provide recommendations for increasing HIV testing rates and status awareness among MSM.
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