166 research outputs found
Helix surfaces in the special linear group
We characterize helix surfaces (constant angle surfaces) in the special
linear group . In particular, we give an explicit local
description of these surfaces in terms of a suitable curve and a 1-parameter
family of isometries of .Comment: Minor corrections. To appear in Annali di Matematica Pura e
Applicata. arXiv admin note: substantial text overlap with arXiv:1206.127
The filamentous fungi culture collection of the Department of Food Science (CCDCA), Federal University of Lavras, Brazil
Brazil has one of the highest levels of biological diversity due to its large geographical
area, high coverage by rainforests, and endemic biomes, such as the
Brazilian Atlantic Forest, Cerrado and Caatinga. Of the estimated 1.5 million
species of fungi only 5% are known. Much of this unknown biodiversity is in the
tropics, which is seriously threatened by some agricultural activities, reinforcing
the urgent need for biodiversity studies in these areas. The maintenance
and preservation of fungal cultures are important elements for such a requirment.
The establishment of a culture collection of filamentous fungi in the
Mycotoxins and Mycology Laboratory, Department of Food Science (CCDCA),
Federal University of Lavras (UFLA) commenced from the bases of species
maintenance, taxonomy, biotechnology and toxigenicity. The laboratory was established
in 2007 to preserve potentially mycotoxigenic fungi, especially ochratoxin
A and aflatoxins producers, which were isolated from food. Currently the
CCDCA has more than 1000 isolates of Aspergillus, Penicillium, Cladosporium,
Fusarium, Alternaria, Chaetomium, Mucor, Eurotium, and Neosartorya. A total
of 66 species are represented which were isolated from food, cave environments,
and soils of the Brazilian Atlantic Forest, Cerrado and Caatinga. A total of 328
cultures are preserved and maintained by periodic subculture, 137 by mineral
oil preservation, and 550 by filter paper preservation. The staff trains graduate
students in the taxonomy of major taxa of importance to agricultural research
and food science. Finally, the CCDCA and UFLA, Brazil, in collaboration with
the IBB-Biological Engineering Centre, Micoteca da Universidade do Minho,
Portugal, intend to develop a project on polyphasic studies of Aspergillus and
Penicillium isolated from various substrates, sources, and environments in Brazil.
To pursue this aim CCDCA intends to: a) preserve Aspergillus and Penicillium
strains for comparative studies between Brazilian regions and worldwide;
b) foster the study of Aspergillus and Penicillium for biotechnological and toxigenic
potential, and training in identification, preservation and distribution;
c) establish quality control of fungal assays; and d) establish the CCDCA as
a member of the global network of culture collections and participate in the
international forums and organisations related to culture collections
Effects of gender and race on prognosis after myocardial infarction: Adverse prognosis for women, particularly black women
Controversy has arisen concerning whether gender influences the prognosis after myocardial infarction. Although some studies have shown there to be no difference between the sexes, most have indicated a worse prognosis for women, attributing this to differences in baseline characteristics. It has been further suggested that black women have a particularly poor prognosis after infarction. To determine the contribution of gender and race to the course of infarction, 816 patients with confirmed myocardial infarction who were enrolled in the Multi-center Investigation of the Limitation of Infarct Size (MILIS) were analyzed. Of those patients, 226 were women and 590 were men, 142 were black and 674 were white.The cumulative mortality rate at 48 months was 36% for women versus 21% for men (p < 0.001, mean follow-up 32 months). The cumulative mortality rate by race was 34% for blacks versus 24% for whites (p < 0.005). Both women and blacks exhibited more baseline characteristics predictive of mortality than did their male or white counterparts. It was possible to account for the greater mortality rate of blacks by identifiable baseline variables; however, even after adjustment, the mortality rate for women remained significantly higher (p < 0.002). The poorer prognosis for women was influenced by a particularly high mortality rate among black women (48%); the mortality rate for white women was 32%, for black men 23% and for white men 21%. The mortality for black women was significantly greater than that of the other subgroups. Thus, findings in the MILIS population indicate that the prognosis after myocardial infarction is worse for women, particularly black women
Hybridization in human evolution: Insights from other organisms
During the late Pleistocene, isolated lineages of hominins exchanged genes thus influencing genomic variation in humans in both the past and present. However, the dynamics of this genetic exchange and associated phenotypic consequences through time remain poorly understood. Gene exchange across divergent lineages can result in myriad outcomes arising from these dynamics and the environmental conditions under which it occurs. Here we draw from our collective research across various organisms, illustrating some of the ways in which gene exchange can structure genomic/phenotypic diversity within/among species. We present a range of examples relevant to questions about the evolution of hominins. These examples are not meant to be exhaustive, but rather illustrative of the diverse evolutionary causes/consequences of hybridization, highlighting potential drivers of human evolution in the context of hybridization including: influences on adaptive evolution, climate change, developmental systems, sex-differences in behavior, Haldane’s rule and the large X-effect, and transgressive phenotypic variation.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151330/1/evan21787.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151330/2/evan21787_am.pd
Influences on gum feeding in primates
This chapter reviews the factors that may affect patterns of gum feeding by primates. These are then examined for mixed-species troops of saddleback (S. fuscicollis) and mustached (S. mystax) tamarins. An important distinction is made between gums produced by tree trunks and branches as a result of damage and those produced by seed pods as part of a dispersal strategy as these may be expected to differ in their biochemistry. Feeding on fruit and Parkia seed pod exudates was more prevalent in the morning whereas other exudates were eaten in the afternoon. This itinerary may represent a deliberate strategy to retain trunk gums in the gut overnight, thus maximising the potential for microbial fermentation of their β-linked oligosaccharides. Both types of exudates were eaten more in the dry than the wet season. Consumption was linked to seasonal changes in resource availability and not the tamarins’ reproductive status pro-viding no support for the suggestion that gums are eaten as a pri-mary calcium source in the later stages of gestation and lactation. The role of availability in determining patterns of consumption is further supported by the finding that dietary overlap for the trunk gums eaten was greater between species within mixed-species troops within years than it was within species between years. These data and those for pygmy marmosets (Cebuella pygmaea) suggest that patterns of primate gummivory may reflect the interaction of prefer-ence and availability for both those able to stimulate gum production and those not
Risky Business? Lethal Attack by a Jaguar Sheds Light on the Costs of Predator Mobbing for Capuchins (Cebus capucinus)
Risk factors for gastrointestinal parasite infections of dogs living around protected areas of the Atlantic Forest: implications for human and wildlife health
American College of Cardiology key data elements and definitions for measuring the clinical management and outcomes of patients with acute coronary syndromes.
Protocol for chromosome-specific probe construction using PRINS, micromanipulation and DOP-PCR techniques
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