The sexual and reproductive health of African American women has been compromised due to multiple experiences of racism, including discriminatory healthcare practices from slavery through the ...post-Civil Rights era. However, studies rarely consider how the historical underpinnings of racism negatively influence the present-day health outcomes of African American women. Although some improvements to ensure equitable healthcare have been made, these historical influences provide an unexplored context for illuminating present-day epidemiology of sexual and reproductive health disparities among African American women.
To account for the unique healthcare experiences influenced by racism, including healthcare provision, we searched online databases for peer-reviewed sources and books published in English only. We explored the link between historical and current experiences of racism and sexual and reproductive health outcomes.
The legacy of medical experimentation and inadequate healthcare coupled with social determinants has exacerbated African American women's complex relationship with healthcare systems. The social determinants of health associated with institutionalized and interpersonal racism, including poverty, unemployment, and residential segregation, may make African American women more vulnerable to disparate sexual and reproductive health outcomes.
The development of innovative models and strategies to improve the health of African American women may be informed by an understanding of the historical and enduring legacy of racism in the United States. Addressing sexual and reproductive health through a historical lens and ensuring the implementation of culturally appropriate programs, research, and treatment efforts will likely move public health toward achieving health equity. Furthermore, it is necessary to develop interventions that address the intersection of the social determinants of health that contribute to sexual and reproductive health inequities.
Abstract
The late-time spectra of Type Ia supernovae (SNe Ia) are powerful probes of the underlying physics of their explosions. We investigate the late-time optical and near-infrared spectra of ...seven SNe Ia obtained at the VLT with XShooter at >200 d after explosion. At these epochs, the inner Fe-rich ejecta can be studied. We use a line-fitting analysis to determine the relative line fluxes, velocity shifts, and line widths of prominent features contributing to the spectra (Fe ii, Ni ii, and Co iii). By focusing on Fe ii and Ni ii emission lines in the ∼7000–7500 Å region of the spectrum, we find that the ratio of stable Ni ii to mainly radioactively produced Fe ii for most SNe Ia in the sample is consistent with Chandrasekhar-mass delayed-detonation explosion models, as well as sub-Chandrasekhar mass explosions that have metallicity values above solar. The mean measured Ni/Fe abundance of our sample is consistent with the solar value. The more highly ionized Co iii emission lines are found to be more centrally located in the ejecta and have broader lines than the Fe ii and Ni ii features. Our analysis also strengthens previous results that SNe Ia with higher
Si ii velocities at maximum light preferentially display blueshifted Fe ii 7155 Å lines at late times. Our combined results lead us to speculate that the majority of normal SN Ia explosions produce ejecta distributions that deviate significantly from spherical symmetry.
▶ Evapotranspiration (ET) data are derived from a range of measurement systems including lysimeters, eddy covariance, Bowen ratio, water balance (gravimetric, neutron meter, other soil water ...sensing), sap flow, scintillometry and even satellite-based remote sensing and direct modeling. ▶ These measurement techniques require substantial experimental care and are prone to substantial biases in reported results. ▶ Basic principles of ET measurement systems are reviewed and causes of common error and biases endemic to systems are discussed. ▶ Recommendations are given for reducing error in ET retrievals. ▶ Upper limits on ET measurements and derived crop coefficients are proposed.
More and more evapotranspiration models, evapotranspiration crop coefficients and associated measurements of evapotranspiration (ET) are being reported in the literature and used to develop, calibrate and test important ET process models. ET data are derived from a range of measurement systems including lysimeters, eddy covariance, Bowen ratio, water balance (gravimetric, neutron meter, other soil water sensing), sap flow, scintillometry and even satellite-based remote sensing and direct modeling. All of these measurement techniques require substantial experimental care and are prone to substantial biases in reported results. Reporting of data containing measurement biases causes substantial confusion and impedance to the advancement of ET models and in the establishment of irrigation water requirements, and translates into substantial economic losses caused by misinformed water management.
Basic principles of ET measuring systems are reviewed and causes of common error and biases endemic to systems are discussed. Recommendations are given for reducing error in ET retrievals. Upper limits on ET measurements and derived crop coefficients are proposed to serve as guidelines. The descriptions of errors common to measurement systems are intended to help practitioners collect better data as well as to assist reviewers of manuscripts and users of data and derived products in assessing quality, integrity, validity and representativeness of reported information. This paper is the first part of a two-part series, where the second part describes recommendations for documentation to be associated with published ET data.
As the rate and magnitude of climate change accelerate, understanding the consequences becomes increasingly important. Species distribution models (SDMs) based on current ecological niche constraints ...are used to project future species distributions. These models contain assumptions that add to the uncertainty in model projections stemming from the structure of the models, the algorithms used to translate niche associations into distributional probabilities, the quality and quantity of data, and mismatches between the scales of modeling and data. We illustrate the application of SDMs using two climate models and two distributional algorithms, together with information on distributional shifts in vegetation types, to project fine-scale future distributions of 60 California landbird species. Most species are projected to decrease in distribution by 2070. Changes in total species richness vary over the state, with large losses of species in some "hotspots" of vulnerability. Differences in distributional shifts among species will change species co-occurrences, creating spatial variation in similarities between current and future assemblages. We use these analyses to consider how assumptions can be addressed and uncertainties reduced. SDMs can provide a useful way to incorporate future conditions into conservation and management practices and decisions, but the uncertainties of model projections must be balanced with the risks of taking the wrong actions or the costs of inaction. Doing this will require that the sources and magnitudes of uncertainty are documented, and that conservationists and resource managers be willing to act despite the uncertainties. The alternative, of ignoring the future, is not an option.
Ocean's least productive waters are expanding Polovina, Jeffrey J.; Howell, Evan A.; Abecassis, Melanie
Geophysical research letters,
February 2008, Letnik:
35, Številka:
3
Journal Article
Recenzirano
Odprti dostop
A 9‐year time series of SeaWiFS remotely‐sensed ocean color data is used to examine temporal trends in the ocean's most oligotrophic waters, those with surface chlorophyll not exceeding 0.07 mg ...chl/m3. In the North and South Pacific, North and South Atlantic, outside the equatorial zone, the areas of low surface chlorophyll waters have expanded at average annual rates from 0.8 to 4.3%/yr and replaced about 0.8 million km2/yr of higher surface chlorophyll habitat with low surface chlorophyll water. It is estimated that the low surface chlorophyll areas in these oceans combined have expanded by 6.6 million km2 or by about 15.0% from 1998 through 2006. In both hemispheres, evidence shows a more rapid expansion of the low surface chlorophyll waters during the winter. The North Atlantic, which has the smallest oligotrophic gyre is expanding most rapidly, both annually at 4.3%/yr and seasonally, in the first quarter at 8.5%/yr. Mean sea surface temperature in each of these 4 subtropical gyres also increased over the 9‐year period. The expansion of the low chlorophyll waters is consistent with global warming scenarios based on increased vertical stratification in the mid‐latitudes, but the rates of expansion we observe already greatly exceed recent model predictions.
Activation of cannabinoid CB1 receptors (CB1R) by delta9-tetrahydrocannabinol (THC) produces a variety of negative effects with major consequences in cannabis users that constitute important ...drawbacks for the use of cannabinoids as therapeutic agents. For this reason, there is a tremendous medical interest in harnessing the beneficial effects of THC. Behavioral studies carried out in mice lacking 5-HT2A receptors (5-HT2AR) revealed a remarkable 5-HT2AR-dependent dissociation in the beneficial antinociceptive effects of THC and its detrimental amnesic properties. We found that specific effects of THC such as memory deficits, anxiolytic-like effects, and social interaction are under the control of 5-HT2AR, but its acute hypolocomotor, hypothermic, anxiogenic, and antinociceptive effects are not. In biochemical studies, we show that CB1R and 5-HT2AR form heteromers that are expressed and functionally active in specific brain regions involved in memory impairment. Remarkably, our functional data shows that costimulation of both receptors by agonists reduces cell signaling, antagonist binding to one receptor blocks signaling of the interacting receptor, and heteromer formation leads to a switch in G-protein coupling for 5-HT2AR from Gq to Gi proteins. Synthetic peptides with the sequence of transmembrane helices 5 and 6 of CB1R, fused to a cell-penetrating peptide, were able to disrupt receptor heteromerization in vivo, leading to a selective abrogation of memory impairments caused by exposure to THC. These data reveal a novel molecular mechanism for the functional interaction between CB1R and 5-HT2AR mediating cognitive impairment. CB1R-5-HT2AR heteromers are thus good targets to dissociate the cognitive deficits induced by THC from its beneficial antinociceptive properties.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A series of biobased phosphorus flame retardants has been prepared by converting starch-derived
-2,5-(hydroxymethyl)furan to the corresponding diacrylate followed by Michael addition of phosphite to ...generate derivatives with phosphorus moieties attached via P-C bonds. All compounds behave as effective flame retardants in DGEBA epoxy resin. The most effective is the DOPO derivative, 2,5-di(3-dopyl-propanoyl)methylfuran. When incorporated into a DGEBA blend at a level to provide 2% phosphorus, a material displaying a LOI of 30, an UL 94 rating of V0 and a 40% reduction in combustion peak heat release rate compared to that for resin containing no additive is obtained. The analogous compounds generated from bisphenol A and tetrabromobisphenol A exhibit similar flame-retarding properties.
Research has indicated that social support is a major buffer of postpartum depression. Yet little is known concerning women’s perceptions on social support during the postpartum period. The objective ...of this study was to explore postpartum women’s views and experiences with social support following childbirth. Four focus groups were conducted with an ethnically diverse sample of women (n = 33) in a large urban teaching hospital in New York City. Participants had completed participation in a postpartum depression randomized trial and were 6–12 months postpartum. Data transcripts were reviewed and analyzed for themes. The main themes identified in the focus group discussions were mother’s major needs and challenges postpartum, social support expectations and providers of support, how mothers mobilize support, and barriers to mobilizing support. Women across all groups identified receipt of instrumental support as essential to their physical and emotional recovery. Support from partners and families was expected and many women believed this support should be provided without asking. Racial/ethnic differences existed in the way women from different groups mobilized support from their support networks. Instrumental support plays a significant role in meeting women’s basic needs during the postpartum period. In addition, women’s expectations surrounding support can have an impact on their ability to mobilize support among their social networks. The results of this study suggest that identifying support needs and expectations of new mothers is important for mothers’ recovery after childbirth. Future postpartum depression prevention efforts should integrate a strong focus on social support.
Significant racial and ethnic disparities in maternal morbidity and mortality exist in the United States. Black women are 3 to 4 times more likely to die a pregnancy-related death as compared with ...white women. Growing research indicates that quality of health care, from preconception through postpartum care, may be a critical lever for improving outcomes for racial and ethnic minority women. This article reviews racial and ethnic disparities in severe maternal morbidities and mortality, underlying drivers of these disparities, and potential levers to reduce their occurrence.
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