52 research outputs found

    Morphological Comparisons of Five Species of Tamarins in Peru

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    Tamarins of the genus Leontocebus (formerly Saguinus), subfamily Callitrichinae, represent one of the most diverse primate taxa but detailed information about their phylogeny is still lacking. Recent molecular phylogenetic analyses have led to the reclassification of many taxa. In Peru, ten subspecies of tamarins were reclassified as eight new species and four new subspecies based on genetic differences among these taxa. However, no one has attempted to determine whether these new “genetic species” have distinguishable morphological traits. To do this, we examined twenty crania and skins representing five Peruvian “genetic species” housed in the Mammals Collection at the Field Museum of Natural History in Chicago, Illinois. We measured thirty linear craniofacial characters using digital calipers and photographed the pelage of all specimens. We log-transformed and analyzed the data using the Discriminant Analysis module of SPSS 23. We qualitatively compared the pelage color and pattern of all furs. Our study demonstrates that the “genetic species” can be distinguished by their cranial anatomy. Thus, the “genetic species” represent morphologically distinct populations, as is expected if they represent evolutionarily distinct taxa.B.S. (Bachelor of Science

    Особливості планування і реалізації проектів ресторанного бізнесу

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    Ресторанний бізнес є однією із найбільш значущих складових індустрії гостинності. Водночас, ресторанний бізнес, з одного боку, є одним із засобів високоліквідного використання капіталу, а з іншого − середовищем із високим ступенем конкурентності. У всьому світі він є одним із найбільш розповсюджених видів малого бізнесу, тому заклади та підприємства ведуть між собою постійну боротьбу за сегментацію ринку, за пошук нових та за утримання постійних споживачів їхньої продукції та послуг. Всі заклади та підприємства повинні мати високий рівень конкурентоспроможності та мати свою унікальність

    Ancient DNA of the pygmy marmoset type specimen Cebuella pygmaea (Spix, 1823) resolves a taxonomic conundrum

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    The pygmy marmoset, the smallest of the anthropoid primates, has a broad distribution in Western Amazonia. Recent studies using molecular and morphological data have identified two distinct species separated by the Napo and Solimões-Amazonas rivers. However, reconciling this new biological evidence with current taxonomy, i.e., two subspecies, Cebuella pygmaea pygmaea (Spix, 1823) and Cebuella pygmaea niveiventris (Lönnberg, 1940), was problematic given the uncertainty as to whether Spix's pygmy marmoset (Cebuella pygmaea pygmaea) was collected north or south of the Napo and Solimões-Amazonas rivers, making it unclear to which of the two newly revealed species the name pygmaea would apply. Here, we present the first molecular data from Spix's type specimen of Cebuella pygmaea, as well as novel mitochondrial genomes from modern pygmy marmosets sampled near the type locality (Tabatinga) on both sides of the river. With these data, we can confirm the correct names of the two species identified, i.e., C. pygmaea for animals north of the Napo and Solimões-Amazonas rivers and C. niveiventris for animals south of these two rivers. Phylogenetic analyses of the novel genetic data placed into the context of cytochrome b gene sequences from across the range of pygmy marmosets further led us to reevaluate the geographical distribution for the two Cebuella species. We dated the split of these two species to 2.54 million years ago. We discuss additional, more recent, subdivisions within each lineage, as well as potential contact zones between the two species in the headwaters of these rivers

    The \u3cem\u3eChlamydomonas\u3c/em\u3e Genome Reveals the Evolution of Key Animal and Plant Functions

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    Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the ∼120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella

    Toward Large FOV High-Resolution X-Ray Imaging Spectrometer: Microwave Multiplexed Readout of 32 TES Microcalorimeters

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    We performed a small-scale demonstration at GSFC of high-resolution x-ray TES microcalorimeters read out using a microwave SQUID multiplexer. This work is part of our effort to develop detector and readout technologies for future space based x-ray instruments such as the microcalorimeter spectrometer envisaged for Lynx, a large mission concept under development for the Astro 2020 Decadal Survey. In this paper we describe our experiment, including details of a recently designed, microwave-optimized low-temperature setup that is thermally anchored to the 50 mK stage of our laboratory ADR. Using a ROACH2 FPGA at room temperature, we simultaneously read out 32 pixels of a GSFC-built detector array via a NIST-built multiplexer chip with Nb coplanar waveguide resonators coupled to RF SQUIDs. The resonators are spaced 6 MHz apart (at approx. 5.9 GHz) and have quality factors of approximately 15,000. Using flux-ramp modulation frequencies of 160 kHz we have achieved spectral resolutions of 3 eV FWHM on each pixel at 6 keV. We will present the measured system-level noise and maximum slew rates, and briefly describe the implications for future detector and readout design

    Factors influencing terrestriality in primates of the Americas and Madagascar

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    Among mammals, the order Primates is exceptional in having a high taxonomic richness in which the taxa are arboreal, semiterrestrial, or terrestrial. Although habitual terrestriality is pervasive among the apes and African and Asian monkeys (catarrhines), it is largely absent among monkeys of the Americas (platyrrhines), as well as galagos, lemurs, and lorises (strepsirrhines), which are mostly arboreal. Numerous ecological drivers and species-specific factors are suggested to set the conditions for an evolutionary shift from arboreality to terrestriality, and current environmental conditions may provide analogous scenarios to those transitional periods. Therefore, we investigated predominantly arboreal, diurnal primate genera from the Americas and Madagascar that lack fully terrestrial taxa, to determine whether ecological drivers (habitat canopy cover, predation risk, maximum temperature, precipitation, primate species richness, human population density, and distance to roads) or species-specific traits (bodymass, group size, and degree of frugivory) associate with increased terrestriality. We collated 150,961 observation hours across 2,227 months from 47 species at 20 sites in Madagascar and 48 sites in the Americas. Multiple factors were associated with ground use in these otherwise arboreal species, including increased temperature, a decrease in canopy cover, a dietary shift away from frugivory, and larger group size. These factors mostly explain intraspecific differences in terrestriality. As humanity modifies habitats and causes climate change, our results suggest that species already inhabiting hot, sparsely canopied sites, and exhibiting more generalized diets, are more likely to shift toward greater ground use

    The landscape of somatic copy-number alteration across human cancers

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    available in PMC 2010 August 18.A powerful way to discover key genes with causal roles in oncogenesis is to identify genomic regions that undergo frequent alteration in human cancers. Here we present high-resolution analyses of somatic copy-number alterations (SCNAs) from 3,131 cancer specimens, belonging largely to 26 histological types. We identify 158 regions of focal SCNA that are altered at significant frequency across several cancer types, of which 122 cannot be explained by the presence of a known cancer target gene located within these regions. Several gene families are enriched among these regions of focal SCNA, including the BCL2 family of apoptosis regulators and the NF-κΒ pathway. We show that cancer cells containing amplifications surrounding the MCL1 and BCL2L1 anti-apoptotic genes depend on the expression of these genes for survival. Finally, we demonstrate that a large majority of SCNAs identified in individual cancer types are present in several cancer types.National Institutes of Health (U.S.) (Dana-Farber/Harvard Cancer Center and Pacific Northwest Prostate Cancer SPOREs, P50CA90578)National Institutes of Health (U.S.) (Dana-Farber/Harvard Cancer Center and Pacific Northwest Prostate Cancer SPOREs, R01CA109038))National Institutes of Health (U.S.) (Dana-Farber/Harvard Cancer Center and Pacific Northwest Prostate Cancer SPOREs, R01CA109467)National Institutes of Health (U.S.) (Dana-Farber/Harvard Cancer Center and Pacific Northwest Prostate Cancer SPOREs, P01CA085859)National Institutes of Health (U.S.) (Dana-Farber/Harvard Cancer Center and Pacific Northwest Prostate Cancer SPOREs, P01CA 098101)National Institutes of Health (U.S.) (Dana-Farber/Harvard Cancer Center and Pacific Northwest Prostate Cancer SPOREs, K08CA122833

    Is the karyotype of neotropical boid snakes really conserved? Cytotaxonomy, chromosomal rearrangements and karyotype organization in the Boidae family

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    Boids are primitive snakes from a basal lineage that is widely distributed in Neotropical region. Many of these species are both morphologically and biogeographically divergent, and the relationship among some species remains uncertain even with evolutionary and phylogenetic studies being proposed for the group. For a better understanding of the evolutionary relationship between these snakes, we cytogenetically analysed 7 species and 3 subspecies of Neotropical snakes from the Boidae family using different chromosomal markers. The karyotypes of Boa constrictor occidentalis, Corallus hortulanus, Eunectes notaeus, Epicrates cenchria and Epicrates assisi are presented here for the first time with the redescriptions of the karyotypes of Boa constrictor constrictor, B. c. amarali, Eunectes murinus and Epicrates crassus. The three subspecies of Boa, two species of Eunectes and three species of Epicrates exhibit 2n = 36 chromosomes. In contrast, C. hortulanus presented a totally different karyotype composition for the Boidae family, showing 2n = 40 chromosomes with a greater number of macrochromosomes. Furthermore, chromosomal mapping of telomeric sequences revealed the presence of interstitial telomeric sites (ITSs) on many chromosomes in addition to the terminal markings on all chromosomes of all taxa analysed, with the exception of E. notaeus. Thus, we demonstrate that the karyotypes of these snakes are not as highly conserved as previously thought. Moreover, we provide an overview of the current cytotaxonomy of the group. © 2016 Viana et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

    The landscape of somatic copy-number alteration across human cancers

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    A powerful way to discover key genes playing causal roles in oncogenesis is to identify genomic regions that undergo frequent alteration in human cancers. Here, we report high-resolution analyses of somatic copy-number alterations (SCNAs) from 3131 cancer specimens, belonging largely to 26 histological types. We identify 158 regions of focal SCNA that are altered at significant frequency across multiple cancer types, of which 122 cannot be explained by the presence of a known cancer target gene located within these regions. Several gene families are enriched among these regions of focal SCNA, including the BCL2 family of apoptosis regulators and the NF-κB pathway. We show that cancer cells harboring amplifications surrounding the MCL1 and BCL2L1 anti-apoptotic genes depend upon expression of these genes for survival. Finally, we demonstrate that a large majority of SCNAs identified in individual cancer types are present in multiple cancer types
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