57 research outputs found
Species and habitat biodiversity measure and conservation at different scale in small Mediterranean islands
Small islands are geographically and ecologically well-defined areas in which
biological processes are easier to schematize than in the mainland. There is a vast
range of biodiversity measures, due to the large concept of biodiversity and the
range of spatial, temporal and taxonomic scales used. Many existing measures
are well designed and informative. But, very often they are inadequate for purposes
beyond those for which they were specifically designed. Knowledge on
trends in biodiversity loss is hindered by the absence of reliable basic data for
most groups of organisms as well as habitats. Plants are primary producers and
key structural elements for most ecosystems and islands are among the best floristically
known territories in the Mediterranean.
Large-scale habitat measurements have been aided greatly by advances in remote
sensing and GIS software. However, the degree of resolution of this technique
is still not adequate for many purposes, such as monitoring many habitats
that occurs on the islands (e.g. temporary Mediterranean pools or ephemeral
therophytic grasslands). The measure of population size is not practical for many
taxa above all in islands that often have sectors of difficult access (e.g. sea cliffs).
Lists and distribution mapping of taxa are probably the most commonly used
surrogate for overall biodiversity at both local and broader scales. The species
level is an accepted standard, because the concept of species is well understood
also by the public, and policy makers. Information on the presence of higher
plants is available for many Mediterranean islands due to records of visiting naturalists,
and formal surveys undertaken by governments and NGOs (e.g. the
PIM initiative). In addition, in the islands the lack of records of a species is more
easily correlated to its disappearance from that territory than it is in the mainland.
Anyway, particular attention has to be put on measurements of rarity and
extinction risk. Most extinctions, after a first peak due to a specific phenomenon,
have a long after-effects, whereby the species may persist at low numbers with
a negligible chance of recovery and a severely diminished role in the ecosystem
Countries with Higher Levels of Gender Equality Show Larger National Sex Differences in Mathematics Anxiety and Relatively Lower Parental Mathematics Valuation for Girls.
Despite international advancements in gender equality across a variety of societal domains, the underrepresentation of girls and women in Science, Technology, Engineering, and Mathematics (STEM) related fields persists. In this study, we explored the possibility that the sex difference in mathematics anxiety contributes to this disparity. More specifically, we tested a number of predictions from the prominent gender stratification model, which is the leading psychological theory of cross-national patterns of sex differences in mathematics anxiety and performance. To this end, we analyzed data from 761,655 15-year old students across 68 nations who participated in the Programme for International Student Assessment (PISA). Most importantly and contra predictions, we showed that economically developed and more gender equal countries have a lower overall level of mathematics anxiety, and yet a larger national sex difference in mathematics anxiety relative to less developed countries. Further, although relatively more mothers work in STEM fields in more developed countries, these parents valued, on average, mathematical competence more in their sons than their daughters. The proportion of mothers working in STEM was unrelated to sex differences in mathematics anxiety or performance. We propose that the gender stratification model fails to account for these national patterns and that an alternative model is needed. In the discussion, we suggest how an interaction between socio-cultural values and sex-specific psychological traits can better explain these patterns. We also discuss implications for policies aiming to increase girls' STEM participation
Characterization of Cyclin E Expression in Multiple Myeloma and Its Functional Role in Seliciclib-Induced Apoptotic Cell Death
Multiple Myeloma (MM) is a lymphatic neoplasm characterized by clonal proliferation of malignant plasma cell that eventually develops resistance to chemotherapy. Drug resistance, differentiation block and increased survival of the MM tumor cells result from high genomic instability. Chromosomal translocations, the most common genomic alterations in MM, lead to dysregulation of cyclin D, a regulatory protein that governs the activation of key cell cycle regulator – cyclin dependent kinase (CDK). Genomic instability was reported to be affected by over expression of another CDK regulator - cyclin E (CCNE). This occurs early in tumorigenesis in various lymphatic malignancies including CLL, NHL and HL. We therefore sought to investigate the role of cyclin E in MM. CCNE1 expression was found to be heterogeneous in various MM cell lines (hMMCLs). Incubation of hMMCLs with seliciclib, a selective CDK-inhibitor, results in apoptosis which is accompanied by down regulation of MCL1 and p27. Ectopic over expression of CCNE1 resulted in reduced sensitivity of the MM tumor cells in comparison to the paternal cell line, whereas CCNE1 silencing with siRNA increased the cell sensitivity to seliciclib. Adhesion to FN of hMMCLs was prevented by seliciclib, eliminating adhesion–mediated drug resistance of MM cells. Combination of seliciclib with flavopiridol effectively reduced CCNE1 and CCND1 protein levels, increased subG1 apoptotic fraction and promoted MM cell death in BMSCs co-culture conditions, therefore over-coming stroma-mediated protection. We suggest that seliciclib may be considered as essential component of modern anti MM drug combination therapy
Characterization of ERK Docking Domain Inhibitors that Induce Apoptosis by Targeting Rsk-1 and Caspase-9
<p>Abstract</p> <p>Background</p> <p>The extracellular signal-regulated kinase-1 and 2 (ERK1/2) proteins play an important role in cancer cell proliferation and survival. ERK1/2 proteins also are important for normal cell functions. Thus, anti-cancer therapies that block all ERK1/2 signaling may result in undesirable toxicity to normal cells. As an alternative, we have used computational and biological approaches to identify low-molecular weight compounds that have the potential to interact with unique ERK1/2 docking sites and selectively inhibit interactions with substrates involved in promoting cell proliferation.</p> <p>Methods</p> <p>Colony formation and water soluble tetrazolium salt (WST) assays were used to determine the effects of test compounds on cell proliferation. Changes in phosphorylation and protein expression in response to test compound treatment were examined by immunoblotting and <it>in vitro </it>kinase assays. Apoptosis was determined with immunoblotting and caspase activity assays.</p> <p>Results</p> <p><it>In silico </it>modeling was used to identify compounds that were structurally similar to a previously identified parent compound, called <b>76</b>. From this screen, several compounds, termed <b>76.2</b>, <b>76.3</b>, and <b>76.4 </b>sharing a common thiazolidinedione core with an aminoethyl side group, inhibited proliferation and induced apoptosis of HeLa cells. However, the active compounds were less effective in inhibiting proliferation or inducing apoptosis in non-transformed epithelial cells. Induction of HeLa cell apoptosis appeared to be through intrinsic mechanisms involving caspase-9 activation and decreased phosphorylation of the pro-apoptotic Bad protein. Cell-based and <it>in vitro </it>kinase assays indicated that compounds <b>76.3 </b>and <b>76.4 </b>directly inhibited ERK-mediated phosphorylation of caspase-9 and the p90Rsk-1 kinase, which phosphorylates and inhibits Bad, more effectively than the parent compound <b>76</b>. Further examination of the test compound's mechanism of action showed little effects on related MAP kinases or other cell survival proteins.</p> <p>Conclusion</p> <p>These findings support the identification of a class of ERK-targeted molecules that can induce apoptosis in transformed cells by inhibiting ERK-mediated phosphorylation and inactivation of pro-apoptotic proteins.</p
The dual PI3K/mTOR inhibitor NVP-BEZ235 inhibits proliferation and induces apoptosis of burkitt lymphoma cells
HIV/SIV Infection Primes Monocytes and Dendritic Cells for Apoptosis
Subversion or exacerbation of antigen-presenting cells (APC) death modulates host/pathogen equilibrium. We demonstrated during in vitro differentiation of monocyte-derived macrophages and monocyte-derived dendritic cells (DCs) that HIV sensitizes the cells to undergo apoptosis in response to TRAIL and FasL, respectively. In addition, we found that HIV-1 increased the levels of pro-apoptotic Bax and Bak molecules and decreased the levels of anti-apoptotic Mcl-1 and FLIP proteins. To assess the relevance of these observations in the context of an experimental model of HIV infection, we investigated the death of APC during pathogenic SIV-infection in rhesus macaques (RMs). We demonstrated increased apoptosis, during the acute phase, of both peripheral blood DCs and monocytes (CD14+) from SIV+RMs, associated with a dysregulation in the balance of pro- and anti-apoptotic molecules. Caspase-inhibitor and death receptors antagonists prevented apoptosis of APCs from SIV+RMs. Furthermore, increased levels of FasL in the sera of pathogenic SIV+RMs were detected, compared to non-pathogenic SIV infection of African green monkey. We suggest that inappropriate apoptosis of antigen-presenting cells may contribute to dysregulation of cellular immunity early in the process of HIV/SIV infection
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Quantile Regression
Features: This work of 2 volumes (in both print and electronic formats) contains 300-350 signed entries by significant figures in the field
Immunological fingerprint of 4CMenB recombinant antigens via protein microarray reveals key immunosignatures correlating with bactericidal activity
Downregulation of Mcl-1 through GSK-3β activation contributes to arsenic trioxide-induced apoptosis in acute myeloid leukemia cells
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