2,698 research outputs found

    Dispersal of a Human-Cultivated Crop by Wild Chimpanzees (Pan troglodytes verus) in a Forest–Farm Matrix

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    This is the author accepted manuscript. The final version is available from Springer verlag via the DOI in this recordWith the conversion of natural habitats to farmland, nonhuman primates (hereafter primates) are increasingly exposed to agricultural crops. Although frugivorous primates are important seed dispersers that sometimes feed on agricultural fruits, evidence for dispersal of crops by primates is lacking. Here, we examine flexible feeding on cacao (Theobroma cacao) fruit and seed dispersal patterns by chimpanzees (Pan troglodytes verus) at Bossou in Guinea, and consequent cacao germination and survival. From direct observations, we confirm that cacao fruit is not an important food to chimpanzees, representing 0.23 % of focal animal feeding time. Chimpanzees ingest cacao pulp and either spit out the large seeds intact from unripe cacao fruit or swallow the seeds from ripe cacao fruits, which are consequently deposited in feces. From ecological surveys we show that chimpanzees distributed cacao extensively throughout their home range, at a mean distance of 407 m ± SE 0.6 (N = 90 clusters, range: 4–1130 m) from cacao plantations. As distance from the cacao plantation increased, cacao plants were more likely to survive. Other factors, including number of cacao plants in a cluster, plant height, and openness of the understory did not predict short-term cacao survival. Cacao plants within the forest did not produce fruit. By contrast, when chimpanzees deposited seeds in a plantation, cacao plants produced fruits as a result of farmers’ maintenance of the area. Our local-scale findings emphasize the complex behavioral and ecological interconnections between coexisting humans and primates in agricultural landscapes and generate interesting questions regarding primate niche construction and crop “ownership” related to who “plants” the crop.Fundação para a Ciência e a Tecnologia, PortugalMEX

    DNA conformational dynamics in the presence of catanionic mixtures

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    DNA conformational behavior in the presence of non-stoichiometric mixtures of two oppositely charged surfactants, cetyltrimethylammonium bromide and sodium octyl sulfate, was directly visualized in an aqueous solution with the use of a fluorescence microscopy technique. It was found that in the presence of cationic-rich catanionic mixtures, DNA molecules exhibit a conformational transition from elongated coil to compact globule states. Moreover, if the catanionic mixtures form positively charged vesicles, DNA is adsorbed onto the surface of the vesicles in a collapsed globular form. When anionic-rich catanionic mixtures are present in the solution, no change in the DNA conformational behavior was detected. Cryogenic transmission electron microscopy, as well as measurements of translational diffusion coefficients of individual DNA chains, supported our optical microscopy observations.http://www.sciencedirect.com/science/article/B6T36-3WRB313-V/1/07d45ede3443f93c49fe5d72c57fdfa

    Radial Temperature Profiles of X-Ray--Emitting Gas Within Clusters of Galaxies

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    Previous analyses of ASCA data of clusters of galaxies have found conflicting results regarding the slope of the temperature profile of the hot X-ray gas within clusters, mainly because of the large, energy-dependent point spread function (PSF) of the ASCA mirrors. We present a summary of all ASCA-determined cluster temperature profiles found in the literature, and find a discrepancy in the radial temperature trend of clusters based on which PSF-correction routine is used. This uncertainty in the cluster temperature profile in turn can lead to large uncertainties in the amount of dark matter in clusters. In this study, we have used ROSAT PSPC data to obtain independent relative temperature profiles for 26 clusters, most of which have had their temperature profiles determined by ASCA. Our aim is not to measure the actual temperature values of the clusters, but to use X-ray color profiles to search for a hardening or softening of the spectra with radius for comparison to ASCA-derived profiles. The radial color profiles indicate that outside of the cooling flow region, the temperature profiles of clusters are in general constant. Within 35% of the virial radius, we find a temperature drop of 20% at 10 keV and 12% at 5 keV can be ruled out at the 99% confidence level. A subsample of non-cooling flow clusters shows that the condition of isothermality applies at very small radii too, although cooling gas complicates this determination in the cooling flow subsample. The colors predicted from the temperature profiles of a series of hydrodynamical cluster simulations match the data very well, although they cannot be used to discriminate among different cosmologies. An additional result is that the color profiles show evidence for a central peak in metallicity in low temperature clusters.Comment: 39 pages, 15 embedded Postscript figures, uses aaspp4.sty, accepted for publication in Astrophysical Journa

    Prognostic value of adiponectin for cardiovascular disease and mortality.

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    Context: Low adiponectin concentrations are associated with the presence of an adverse cardiovascular disease (CVD) risk profile. Objective: We studied the predictive value of adiponectin levels for all-cause and CVD mortality and CVD morbidity. Design, Setting, and Participants: This was a population-based cohort study in Hoorn, The Netherlands, which started in 1989 and included 2484 participants, aged 50-75 yr. Main Outcome Measures: Hazard ratios (HRs) with 95% confidence interval per SD change in log-adiponectin for all-cause and CVD mortality and CVD morbidity were calculated. Results: Adiponectin was determined for 1077 men and 1248 women. Higher adiponectin reduced the risk of nonfatal CVD in women [HR with 95% confidence interval 0.72 (0.61-0.90) in women and 0.92 (0.79-1.06) in men], but not the risk of all-cause or CVD mortality. In contrast, after adjustment for cardiovascular risk factors, higher adiponectin was a significant predictor of all-cause and CVD mortality [HR for CVD mortality 1.45 (1.10-1.92) in women and 1.30 (1.04-1.63) in men]. Higher adiponectin was associated with an increased risk of CVD mortality in people with prevalent CVD [HR 1.27 (0.98-1.63)] and with reduced risk in people without [HR 0.90 (0.73-1.11)]. After adjustment for cardiovascular risk factors, the HRs for CVD mortality were 1.60 (1.14-2.23) for patients with and 1.38 (1.06-1.80) for patients without prevalent CVD. Conclusions: High levels of adiponectin predict mortality, in particular in patients with prevalent CVD. We hypothesize that adiponectin protects against metabolic and vascular diseases, but in patients already afflicted with CVD, adiponectin is compensatory up-regulated and, therefore, indicates a high mortality risk

    High energy-density capacitor based on ammonium salt type ionic liquids and their mixing effect by propylene carbonate

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    © The Electrochemical Society, Inc. 2005. All rights reserved. Except as provided under U.S. copyright law, this work may not be reproducted, resold, distributed, or modified without the express permission of The Electrochemical Society (ECS). The archival version of this work was published in JOURNAL OF THE ELECTROCHEMICAL SOCIETY 152 (4): A710-A715 2005.ArticleJournal of the Electrochemical Society. 152(4):A710-A715 (2005)journal articl

    Chimpanzee Personality and the Arginine Vasopressin Receptor 1A Genotype

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    Polymorphisms of the arginine vasopressin receptor 1a (AVPR1a) gene have been linked to various measures related to human social behavior, including sibling conflict and agreeableness. In chimpanzees, AVPR1a polymorphisms have been associated with traits important for social interactions, including sociability, joint attention, dominance, conscientiousness, and hierarchical personality dimensions named low alpha/stability, disinhibition, and negative emotionality/low dominance. We examined associations between AVPR1a and six personality domains and hierarchical personality dimensions in 129 chimpanzees (Pan troglodytes) living in Japan or in a sanctuary in Guinea. We fit three linear and three animal models. The first model included genotype, the second included sex and genotype, and the third included genotype, sex, and sex × genotype. All personality phenotypes were heritable. Chimpanzees possessing the long form of the allele were higher in conscientiousness, but only in models that did not include the other predictors; however, additional analyses suggested that this may have been a consequence of study design. In animal models that included sex and sex × genotype, chimpanzees homozygous for the short form of the allele were higher in extraversion. Taken with the findings of previous studies of chimpanzees and humans, the findings related to conscientiousness suggest that AVPR1a may be related to lower levels of impulsive aggression. The direction of the association between AVPR1a genotype and extraversion ran counter to what one would expect if AVPR1a was related to social behaviors. These results help us further understand the genetic basis of personality in chimpanzees

    First GIS analysis of modern stone tools used by wild chimpanzees (Pan troglodytes verus) in Bossou, Guinea, West Africa

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    Stone tool use by wild chimpanzees of West Africa offers a unique opportunity to explore the evolutionary roots of technology during human evolution. However, detailed analyses of chimpanzee stone artifacts are still lacking, thus precluding a comparison with the earliest archaeological record. This paper presents the first systematic study of stone tools used by wild chimpanzees to crack open nuts in Bossou (Guinea-Conakry), and applies pioneering analytical techniques to such artifacts. Automatic morphometric GIS classification enabled to create maps of use wear over the stone tools (anvils, hammers, and hammers/anvils), which were blind tested with GIS spatial analysis of damage patterns identified visually. Our analysis shows that chimpanzee stone tool use wear can be systematized and specific damage patterns discerned, allowing to discriminate between active and passive pounders in lithic assemblages. In summary, our results demonstrate the heuristic potential of combined suites of GIS techniques for the analysis of battered artifacts, and have enabled creating a referential framework of analysis in which wild chimpanzee battered tools can for the first time be directly compared to the early archaeological record.Leverhulme Trust [IN-052]; MEXT [20002001, 24000001]; JSPS-U04-PWS; FCT-Portugal [SFRH/BD/36169/2007]; Wenner-Gren Foundation for Anthropological Researc

    Distinct expression patterns of the E3 ligase SIAH-1 and its partner Kid/KIF22 in normal tissues and in the breast tumoral processes

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    SIAH proteins are the human members of an highly conserved family of E3 ubiquitin ligases. Several data suggest that SIAH proteins may have a role in tumor suppression and apoptosis. Previously, we reported that SIAH-1 induces the degradation of Kid (KIF22), a chromokinesin protein implicated in the normal progression of mitosis and meiosis, by the ubiquitin proteasome pathway. In human breast cancer cells stably transfected with SIAH-1, Kid/KIF22 protein level was markedly reduced whereas, the Kid/KIF22 mRNA level was increased. This interaction has been further elucidated through analyzing SIAH and Kid/KIF22 expression in both paired normal and tumor tissues and cell lines. It was observed that SIAH-1 protein is widely expressed in different normal tissues, and in cells lines but showing some differences in western blotting profiles. Immunofluorescence microscopy shows that the intracellular distribution of SIAH-1 and Kid/KIF22 appears to be modified in human tumor tissues compared to normal controls. When mRNA expression of SIAH-1 and Kid/KIF22 was analyzed by real-time PCR in normal and cancer breast tissues from the same patient, a large variation in the number of mRNA copies was detected between the different samples. In most cases, SIAH-1 mRNA is decreased in tumor tissues compared to their normal counterparts. Interestingly, in all breast tumor tissues analyzed, variations in the Kid/KIF22 mRNA levels mirrored those seen with SIAH-1 mRNAs. This concerted variation of SIAH-1 and Kid/KIF22 messengers suggests the existence of an additional level of control than the previously described protein-protein interaction and protein stability regulation. Our observations also underline the need to re-evaluate the results of gene expression obtained by qRT-PCR and relate it to the protein expression and cellular localization when matched normal and tumoral tissues are analyzed

    Ram pressure stripping of the cool core of the Ophiuchus Cluster

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    (abridged) We report results from a Chandra study of the central regions of the nearby, X-ray bright, Ophiuchus Cluster (z = 0.03), the second-brightest cluster in the sky. Our study reveals a dramatic, close-up view of the stripping and potential destruction of a cool core within a rich cluster. The X-ray emission from the Ophiuchus Cluster core exhibits a comet-like morphology extending to the north, driven by merging activity, indicative of ram-pressure stripping caused by rapid motion through the ambient cluster gas. A cold front at the southern edge implies a velocity of 1000±\pm200 km/s (M~0.6). The X-ray emission from the cluster core is sharply peaked. As previously noted, the peak is offset by 4 arcsec (~2 kpc) from the optical center of the associated cD galaxy, indicating that ram pressure has slowed the core, allowing the relatively collisionless stars and dark matter to carry on ahead. The cluster exhibits the strongest central temperature gradient of any massive cluster observed to date: the temperature rises from 0.7 keV within 1 kpc of the brightness peak, to 10 keV by 30 kpc. A strong metallicity gradient is also observed within the same region. This supports a picture in which the outer parts of the cool core have been stripped by ram-pressure due to its rapid motion. The cooling time of the innermost gas is very short, ~5×107\times10^7 yrs. Within the central 10 kpc radius, multiple small-scale fronts and a complex thermodynamic structure are observed, indicating significant motions. Beyond the central 50 kpc, and out to a radius ~150 kpc, the cluster appears relatively isothermal and has near constant metallicity. The exception is a large, coherent ridge of enhanced metallicity observed to trail the cool core, and which is likely to have been stripped from it.Comment: Accepted to MNRAS. 11 pages, 9 figure
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