Macro-Climatic Distribution Limits Show Both Niche Expansion and Niche Specialization among C4 Panicoids

Grasses are ancestrally tropical understory species whose current dominance in warm open habitats is linked to the evolution of C4 photosynthesis. C4 grasses maintain high rates of photosynthesis in warm and water stressed environments, and the syndrome is considered to induce niche shifts into these habitats while adaptation to cold ones may be compromised. Global biogeographic analyses of C4 grasses have, however, concentrated on diversity patterns, while paying little attention to distributional limits. Using phylogenetic contrast analyses, we compared macro-climatic distribution limits among ~1300 grasses from the subfamily Panicoideae, which includes 4/5 of the known photosynthetic transitions in grasses. We explored whether evolution of C4 photosynthesis correlates with niche expansions, niche changes, or stasis at subfamily level and within the two tribes Paniceae and Paspaleae. We compared the climatic extremes of growing season temperatures, aridity, and mean temperatures of the coldest months. We found support for all the known biogeographic distribution patterns of C4 species, these patterns were, however, formed both by niche expansion and niche changes. The only ubiquitous response to a change in the photosynthetic pathway within Panicoideae was a niche expansion of the C4 species into regions with higher growing season temperatures, but without a withdrawal from the inherited climate niche. Other patterns varied among the tribes, as macro-climatic niche evolution in the American tribe Paspaleae differed from the pattern supported in the globally distributed tribe Paniceae and at family level.Fil: Aagesen, Lone. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Biganzoli, Fernando. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bena, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Godoy Bürki, Ana Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Reinheimer, Renata. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Zuloaga, Fernando Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentin

Nutritional status and growth of indigenous Xavante children, Central Brazil

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to characterize the nutritional status of Xavante Indian children less than 10 years of age in Central Brazil and to evaluate the hypothesis of an association between child nutrition and socioeconomic differentiation in this population.</p> <p>Methods</p> <p>A cross-sectional study was conducted in July 2006 that included all children under the age of 10 from the Xavante village Pimentel Barbosa in Mato Grosso, Brazil. The data collected included weight, height, and sociodemographic information. Sociodemographic data were used to generate two indices ("income" and "wealth") and to determine the proportion of adults in each household. Descriptive analyses were performed for weight-for-age (W/A), height-for-age (H/A), and weight-for-height (W/H) using the NCHS and the WHO growth references. Univariate and multivariate analyses were conducted using H/A and W/A as a response variables.</p> <p>Results</p> <p>Of a total of 246 children under the age of ten residing in the village, 232 (94.3%) were evaluated. Following the NCHS reference, 5.6% of children under the age of ten presented low W/A and 14.7% presented low H/A. Among children under the age of five, deficit percentages for weight and height were 4.5% and 29.9%, respectively, following the WHO curves. Among children < 2 years of age, H/A index variability was found to be directly related to child's age and inversely related to the proportion of adults in the household. Maternal BMI was positively associated with growth for children from 2 to 4 years of age, explaining 11.5% of the z-score variability for the H/A index. For children 5 years of age and older, the wealth index and maternal height were positively associated with H/A. No significant associations were found using W/A as the dependent variable.</p> <p>Conclusion</p> <p>This study demonstrated that undernutrition, in particular linear growth deficit, is a notable health issue for Xavante children. These findings contrast with the nutritional profile observed among Brazilian children nationally, which is characterized by a sharp decline in child undernutrition in recent decades, even in the poorest regions of the country. This discrepancy calls attention to the persistent health disparities that exist between indigenous and non-indigenous people in Brazil.</p

AYUMS: an algorithm for completely automatic quantitation based on LC-MS/MS proteome data and its application to the analysis of signal transduction

BACKGROUND: Comprehensive description of the behavior of cellular components in a quantitative manner is essential for systematic understanding of biological events. Recent LC-MS/MS (tandem mass spectrometry coupled with liquid chromatography) technology, in combination with the SILAC (Stable Isotope Labeling by Amino acids in Cell culture) method, has enabled us to make relative quantitation at the proteome level. The recent report by Blagoev et al. (Nat. Biotechnol., 22, 1139–1145, 2004) indicated that this method was also applicable for the time-course analysis of cellular signaling events. Relative quatitation can easily be performed by calculating the ratio of peak intensities corresponding to differentially labeled peptides in the MS spectrum. As currently available software requires some GUI applications and is time-consuming, it is not suitable for processing large-scale proteome data. RESULTS: To resolve this difficulty, we developed an algorithm that automatically detects the peaks in each spectrum. Using this algorithm, we developed a software tool named AYUMS that automatically identifies the peaks corresponding to differentially labeled peptides, compares these peaks, calculates each of the peak ratios in mixed samples, and integrates them into one data sheet. This software has enabled us to dramatically save time for generation of the final report. CONCLUSION: AYUMS is a useful software tool for comprehensive quantitation of the proteome data generated by LC-MS/MS analysis. This software was developed using Java and runs on Linux, Windows, and Mac OS X. Please contact [email protected] if you are interested in the application. The project web page is

GLUT 5 Is Not Over-Expressed in Breast Cancer Cells and Patient Breast Cancer Tissues

F18 2-Fluoro 2-deoxyglucose (FDG) has been the gold standard in positron emission tomography (PET) oncologic imaging since its introduction into the clinics several years ago. Seeking to complement FDG in the diagnosis of breast cancer using radio labeled fructose based analogs, we investigated the expression of the chief fructose transporter-GLUT 5 in breast cancer cells and human tissues. Our results indicate that GLUT 5 is not over-expressed in breast cancer tissues as assessed by an extensive immunohistochemistry study. RT-PCR studies showed that the GLUT 5 mRNA was present at minimal amounts in breast cancer cell lines. Further knocking down the expression of GLUT 5 in breast cancer cells using RNA interference did not affect the fructose uptake in these cell lines. Taken together these results are consistent with GLUT 5 not being essential for fructose uptake in breast cancer cells and tissues

Is there a divide between local medicinal knowledge and Western medicine? a case study among native Amazonians in Bolivia

Background: Interest in ethnomedicine has grown in the last decades, with much research focusing on how local medicinal knowledge can contribute to Western medicine. Researchers have emphasized the divide between practices used by local medical practitioners and Western doctors. However, researchers have also suggested that merging concepts and practices from local medicinal knowledge and Western science have the potential to improve public health and support medical independence of local people. In this article we study the relations between local and Western medicinal knowledge within a native Amazonian population, the Tsimane'. Methods: We used the following methods: 1) participant observation and semi-structured interviews to gather background information, 2) free-listing and pile-sorting to assess whether Tsimane' integrate local medicinal knowledge and Western medicine at the conceptual level, 3) surveys to assess to what extent Tsimane' combine local medicinal knowledge with Western medicine in actual treatments, and 4) a participatory workshop to assess the willingness of Tsimane' and Western medical specialists to cooperate with each other. Results: We found that when asked about medical treatments, Tsimane' do not include Western treatments in their lists, however on their daily practices, Tsimane' do use Western treatments in combination with ethnomedical treatments. We also found that Tsimane' healers and Western doctors express willingness to cooperate with each other and to promote synergy between local and Western medical systems. Conclusion: Our findings contrast with previous research emphasizing the divide between local medical practitioners and Western doctors and suggests that cooperation between both health systems might be possible

Identification of ORC1/CDC6-Interacting Factors in Trypanosoma brucei Reveals Critical Features of Origin Recognition Complex Architecture

DNA Replication initiates by formation of a pre-replication complex on sequences termed origins. In eukaryotes, the pre-replication complex is composed of the Origin Recognition Complex (ORC), Cdc6 and the MCM replicative helicase in conjunction with Cdt1. Eukaryotic ORC is considered to be composed of six subunits, named Orc1–6, and monomeric Cdc6 is closely related in sequence to Orc1. However, ORC has been little explored in protists, and only a single ORC protein, related to both Orc1 and Cdc6, has been shown to act in DNA replication in Trypanosoma brucei. Here we identify three highly diverged putative T. brucei ORC components that interact with ORC1/CDC6 and contribute to cell division. Two of these factors are so diverged that we cannot determine if they are eukaryotic ORC subunit orthologues, or are parasite-specific replication factors. The other we show to be a highly diverged Orc4 orthologue, demonstrating that this is one of the most widely conserved ORC subunits in protists and revealing it to be a key element of eukaryotic ORC architecture. Additionally, we have examined interactions amongst the T. brucei MCM subunits and show that this has the conventional eukaryotic heterohexameric structure, suggesting that divergence in the T. brucei replication machinery is limited to the earliest steps in origin licensing

Experimental Beetle Metapopulations Respond Positively to Dynamic Landscapes and Reduced Connectivity

Interactive effects of multiple environmental factors on metapopulation dynamics have received scant attention. We designed a laboratory study to test hypotheses regarding interactive effects of factors affecting the metapopulation dynamics of red flour beetle, Tribolium castaneum. Within a four-patch landscape we modified resource level (constant and diminishing), patch connectivity (high and low) and patch configuration (static and dynamic) to conduct a 23 factorial experiment, consisting of 8 metapopulations, each with 3 replicates. For comparison, two control populations consisting of isolated and static subpopulations were provided with resources at constant or diminishing levels. Longitudinal data from 22 tri-weekly counts of beetle abundance were analyzed using Bayesian Poisson generalized linear mixed models to estimate additive and interactive effects of factors affecting abundance. Constant resource levels, low connectivity and dynamic patches yielded greater levels of adult beetle abundance. For a given resource level, frequency of colonization exceeded extinction in landscapes with dynamic patches when connectivity was low, thereby promoting greater patch occupancy. Negative density dependence of pupae on adults occurred and was stronger in landscapes with low connectivity and constant resources; these metapopulations also demonstrated greatest stability. Metapopulations in control landscapes went extinct quickly, denoting lower persistence than comparable landscapes with low connectivity. When landscape carrying capacity was constant, habitat destruction coupled with low connectivity created asynchronous local dynamics and refugia within which cannibalism of pupae was reduced. Increasing connectivity may be counter-productive and habitat destruction/recreation may be beneficial to species in some contexts

Role of the IL-1 Pathway in Dopaminergic Neurodegeneration and Decreased Voluntary Movement

Interleukin-1 (IL-1), a proinflammatory cytokine synthesized and released by activated microglia, can cause dopaminergic neurodegeneration leading to Parkinsons disease (PD). However, it is uncertain whether IL-1 can act directly, or by exacerbating the harmful actions of other brain insults. To ascertain the role of the IL-1 pathway on dopaminergic neurodegeneration and motor skills during aging, we compared mice with impaired [caspase-1 knockout (casp1(-/-))] or overactivated IL-1 activity [IL-1 receptor antagonist knockout (IL-1ra(-/-))] to wild-type (wt) mice at young and middle age. Their motor skills were evaluated by the open-field and rotarod tests, and quantification of their dopamine neurons and activated microglia within the substantia nigra were performed by immunohistochemistry. IL-1ra(-/-) mice showed an age-related decline in motor skills, a reduced number of dopamine neurons, and an increase in activated microglia when compared to wt or casp1(-/-) mice. Casp1(-/-) mice had similar changes in motor skills and dopamine neurons, but fewer activated microglia cells than wt mice. Our results suggest that the overactivated IL-1 pathway occurring in IL-1ra(-/-) mice in the absence of inflammatory interventions (e.g., intracerebral injections performed in animal models of PD) increased activated microglia, decreased the number of dopaminergic neurons, and reduced their motor skills. Decreased IL-1 activity in casp1(-/-) mice did not yield clear protective effects when compared with wt mice. In summary, in the absence of overt brain insults, chronic activation of the IL-1 pathway may promote pathological aspects of PD per se, but its impairment does not appear to yield advantages over wt mice.Funding Agencies|John Curtin School of Medical Research, The Australian National University</p

Characterization of Leishmania donovani MCM4: Expression Patterns and Interaction with PCNA

Events leading to origin firing and fork elongation in eukaryotes involve several proteins which are mostly conserved across the various eukaryotic species. Nuclear DNA replication in trypanosomatids has thus far remained a largely uninvestigated area. While several eukaryotic replication protein orthologs have been annotated, many are missing, suggesting that novel replication mechanisms may apply in this group of organisms. Here, we characterize the expression of Leishmania donovani MCM4, and find that while it broadly resembles other eukaryotes, noteworthy differences exist. MCM4 is constitutively nuclear, signifying that, unlike what is seen in S.cerevisiae, varying subcellular localization of MCM4 is not a mode of replication regulation in Leishmania. Overexpression of MCM4 in Leishmania promastigotes causes progress through S phase faster than usual, implicating a role for MCM4 in the modulation of cell cycle progression. We find for the first time in eukaryotes, an interaction between any of the proteins of the MCM2-7 (MCM4) and PCNA. MCM4 colocalizes with PCNA in S phase cells, in keeping with the MCM2-7 complex being involved not only in replication initiation, but fork elongation as well. Analysis of a LdMCM4 mutant indicates that MCM4 interacts with PCNA via the PIP box motif of MCM4 - perhaps as an integral component of the MCM2-7 complex, although we have no direct evidence that MCM4 harboring a PIP box mutation can still functionally associate with the other members of the MCM2-7 complex- and the PIP box motif is important for cell survival and viability. In Leishmania, MCM4 may possibly help in recruiting PCNA to chromatin, a role assigned to MCM10 in other eukaryotes