19 research outputs found
Recommended from our members
Groundswell : Preparing for Internal Climate Migration
This report, which focuses on three regionsâSub-Saharan Africa, South Asia, and Latin America that together represent 55 percent of the developing worldâs populationâfinds that climate change will push tens of millions of people to migrate within their countries by 2050. It projects that without concrete climate and development action, just over 143 million peopleâor around 2.8 percent of the population of these three regionsâcould be forced to move within their own countries to escape the slow-onset impacts of climate change. They will migrate from less viable areas with lower water availability and crop productivity and from areas affected by rising sea level and storm surges. The poorest and most climate vulnerable areas will be hardest hit. These trends, alongside the emergence of âhotspotsâ of climate in- and out-migration, will have major implications for climate-sensitive sectors and for the adequacy of infrastructure and social support systems. The report finds that internal climate migration will likely rise through 2050 and then accelerate unless there are significant cuts in greenhouse gas emissions and robust development action
Multiancestry analysis of the HLA locus in Alzheimerâs and Parkinsonâs diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes
Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinsonâs disease (PD) and Alzheimerâs disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased AÎČ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues
The effectiveness of environmental policies on reducing deforestation in the Brazilian Amazon
Preserving forests is important in the fight against climate change. Indigenous peoples tend to be good stewards of forests so that they can be preserved for future generations. This research covers whether the policy of providing indigenous communities with land titles saves forests, using impact evaluation to compare 150 indigenous communities living on 400,000 km2 of rainforest (or 8 percent of the Legal Amazon) with and without land titles. When comparing indigenous communities with and without land titles, the difference between both groups is small. The reason for this finding is that remote indigenous territories are not yet threatened by deforestation and therefore do not show a significant difference between both groups. However, satellite images clearly show that some indigenous territories can act as a buffer against deforestation
Calcium isotope fractionation during coccolith formation in Emiliania huxleyi: Independence of growth and calcification rate
[1] Recently, calcium isotope fractionation in the coccolithophore Emiliania huxleyi was shown to exhibit a significant temperature dependency. An important subsequent question in this context is whether the observed fractionation patterns are caused by temperature itself or related growth rate changes. In order to separate growth and calcification rate effects from direct temperature effects, batch culture experiments with the coccolithophore E. huxleyi were conducted under varying light intensities. Despite large changes in cellular growth and calcification rates, calcium isotope fractionation remained constant. Independence of calcium isotope fractionation on growth and calcification was also obtained in two additional sets of experiments in which growth rates changed in response to varying calcium concentration and seawater salinity. These experiments also showed no direct effects of calcium concentration and salinity on calcium isotope fractionation. Values for calcium isotope fractionation of E. huxleyi coccoliths fell within a range of â1.0 to â1.6 (1000 lnα), confirming earlier results. This range is similar to that observed in several foraminiferal species and coccolith oozes, suggesting a rather homogeneous calcium isotopic composition in marine biogenic calcite. Our data further show that the calcium isotope fractionation does not change with changing isotopic composition of seawater. This is a basic requirement for reconstructing the calcium isotopic composition of the ocean over time
Cellular calcium pathways and isotope fractionation in Emiliania huxleyi
The marine calcifying algae Emiliania huxleyi (coccolithophores) was grown in laboratory cultures under varying conditions with respect to the environmental parameters of temperature and carbonate ion concentration [CO32-] concentration. The Ca isotope composition of E. huxleyi's coccoliths reveals new insights into fractionation processes during biomineralization. The temperature-dependent Ca isotope fractionation resembles previous calibrations of inorganic and biogenic calcite and aragonite. Unlike inorganically precipitated calcite, the [CO32-] concentration of the medium has no significant effect on the Ca isotope composition of the coccoliths. These results indicate a decoupling of the chemical properties of the bulk medium and the calcifying vesicle. Cellular Ca pathways of E. huxleyi indicate that fractionation cannot occur at the crystal surface, as occurs during inorganic precipitation. The dominant processes leading to the observed Ca isotope fractionation pattern in E. huxleyi are most likely the dehydration of the Ca aquocomplex at the plasma membrane and the attachment of dissolved Ca to proteins of Ca channels. The independence of Ca isotope fractionation from [CO32-] and the small temperature dependence of E. huxleyi are also important for defining the isotopic signature of the oceanic Ca sink. Since coccolithophores contribute to about half the global CaCO3 production, a relatively uniform isotopic composition of the oceanic Ca sink is further supported
Functional analysis of NKX3.1 in LNCaP prostate cancer cells by RNA interference
The function of the androgen-regulated homeobox protein NKX3.1 in prostate cancer is controversial. NKX3.1 is necessary for correct prostate development and undergoes frequent allelic loss in prostate cancer. However, no mutations occur in the coding region and some particularly aggressive cancers over-express the protein. Nevertheless NKX3.1 is often referred to as candidate tumor suppressor gene. Recent findings suggest a function in protection against oxidative damage involved in prostate carcinogenesis. Thus NKX3.1 may act differently at various stages of prostate cancer. Unlike a classical tumor suppressor NKX3.1 is up-regulated by androgens and down-regulated by phytoestrogens. In this study we performed RNAi based functional analysis by knocking down NKX3.1 expression in LNCaP prostate cancer cells and analyzing the impact of NKX3.1 on gene expression and cell proliferation. Knockdown of NKX3.1 evoked a massive down-regulation of NKX3.1 expression, followed by reduction in mRNA expression of the androdrogen receptor (AR) and the insulinlike growth factor receptor (IGF-1R). Western blot analysis showed strong decreases of NKX3.1, AR, and IGF-1R protein expression. Concomitantly, cell proliferation decreased and expression of prostate-specific antigen (PSA) mRNA and its secretion were diminished, whereas expression of IGF binding protein 3 (IGFBP-3) and MMP tissue inhibitor 3 (TIMP-3) was up-regulated. In tumor cells not deprived of NKX3.1 expression this gene still has a function which might differ from its role in prostate development and carcinogenesis. NKX3.1 knock-down altered the expression of genes highly relevant in prostate cancer cell proliferation and apoptosis. In LNCaP NKX3.1 most probably plays the role of an androgenregulated transcription factor whose down-regulation is paralleled by anti-proliferative and pro-apoptotic effects. Since NKX3.1 can regulate AR expression it may become a target for interference in hormone refractory prostate carcinoma