101 research outputs found
Adoption of \u3ci\u3eBrachiaria\u3c/i\u3e Grasses in Mexico and Central America: A Successful Story
In Latin America and the Caribbean (LAC) there has been a major effort to develop new pastures technologies, to increase livestock productivity for the extensive systems prevailing in the tropical lowlands. This multi-national and inter-institutional effort was initiated through the International Network for the Evaluation of Tropical Pastures (RIEPT, by its name in Spanish), which operated from 1976 to 1996 under CIAT leadership. This network became a platform for institutions to train technicians, share forage material from existing gene banks, study the behaviour of new germplasm under different environments, and established the exchange of scientific information to extrapolate research results (Toledo, 1982). Six hundred and forty five agronomists from 24 countries in LAC were trained by RIEPT, in subjects related to forage agronomy and pasture evaluation. Training was key for the success of RIEPT, because these professionals carried out evaluations of new and improved forages under contrasting ecosystems and provided feedback. In addition, during this period participating institutions in RIEPT released 11 selected grasses as commercial cultivars, most of them from the Brachiaria genus, as well as 16 forage legume cultivars (CIAT, 2003). In Central America and Mexico these cultivars were released between 1990 and 1996. Forage evaluation activities in this region continues at present through a joint research agenda between CIAT and ILRI, as well as between CIAT and the private seed sector. Of all pasture cultivars released; grasses from the Brachiaria genus currently dominate the market – accounting for approximately 84% of all grass seed sales in Mexico and Honduras, 90% in Nicaragua, 85% in Costa Rica, and 97% in Panama during the last 5 years (Holmann et al., 2004). The objective of this paper is to estimate the impact of the adoption of Brachiaria grasses released through RIEPT during the period 1990-2003 on milk and beef production and to describe how this was achieved
Basal and Frontal Accretion Processes versus BSR Characteristics along the Chilean Margin
Multichannel seismic reflection data recorded between Itata (36°S) and Coyhaique offshores (43°S) were processed to obtain seismic images. Analysis of the seismic profiles revealed that weak and discontinuous bottom simulating reflectors were associated to basal accretion processes, while strong and continuous bottom simulating reflectors were associated to frontal accretion processes. This can be explained considering that during basal accretion processes, extensional tectonic movements due to uplifting can favour fluid escapes giving origin to weaker and most discontinuous bottom simulating reflectors. During frontal accretion processes (folding and thrusting), high fluid circulation and stable tectonic conditions however can be responsible of stronger and most continuous bottom simulating reflectors. Along the Arauco-Valdivia offshores, steep accretionary prisms, normal faults, slope basins, and thicker underplated sediment bed were associated to basal accretion, while along the Itata, Chiloe and Coyhaique offshores, small accretionary prisms, folding, and thinner underplated sediment bed were associated to frontal accretion
The Effects of Cultivation Site on Forage Quality of Calliandra calothyrsus var. Patulul
An in vitro experiment was performed to compare the forage quality of foliage of Calliandra (Calliandra calothyrsus Meissner var. Patulul) cultivated on either low or medium-fertility soils in Colombia and Kenya, respectively. A grass-alone diet, with and without urea supplementation, and five legume-supplemented diets (1/3 of dietary dry matter) were tested with the rumen simulation technique (Rusitec) (n=4). The legume supplements consisted of Cratylia (Cratylia argentea), Calliandra from Colombia or Kenya, or 1:1 mixtures of Cratylia with Calliandra Colombia or Kenya. The tannin content of Calliandra Colombia was almost twice as high as that of Calliandra Kenya. Supplementation with urea or Cratylia alone, but not with Calliandra alone, increased ammonia concentration in the fermenter fluid. Unlike Calliandra Colombia, Calliandra Kenya in mixture with Cratylia increased ammonia concentration. The apparent degradation of organic matter increased with all types of supplementation, except with Calliandra Colombia alone. Although the foliage of Calliandra from the two cultivation sites had similar contents of organic matter, crude protein and neutral detergent fibre, they differed in␣nearly all fermentation properties. The material from Kenya showed a higher apparent nutrient degradability. These results indicate that C. calothyrsus var. Patulul cultivated at the Kenyan site had a clearly higher forage quality than foliage from the same variety cultivated in Colombia. However, both materials had a much lower forage quality than Cratylia. The Cratylia-related effects on ruminal fermentation were mainly the results of an increased supply of fermentable nitrogenous compounds as was obvious from the comparison with the urea-supplemented gras
Ethnicity and Cutaneous Melanoma in the City of Sao Paulo, Brazil: A Case-Control Study
Background: Over the last century the incidence of cutaneous melanoma has increased worldwide, a trend that has also been observed in Brazil. The identified risk factors for melanoma include the pattern of sun exposure, family history, and certain phenotypic features. In addition, the incidence of melanoma might be influenced by ethnicity. Like many countries, Brazil has high immigration rates and consequently a heterogenous population. However, Brazil is unique among such countries in that the ethnic heterogeneity of its population is primarily attributable to admixture. This study aimed to evaluate the contribution of European ethnicity to the risk of cutaneous melanoma in Brazil. Methodology/Principal Findings: We carried out a hospital-based case-control study in the metropolitan area of Sao Paulo, Brazil. We evaluated 424 hospitalized patients (202 melanoma patients and 222 control patients) regarding phenotypic features, sun exposure, and number of grandparents born in Europe. Through multivariate logistic regression analysis, we found the following variables to be independently associated with melanoma: grandparents born in Europe-Spain (OR = 3.01, 95% CI: 1.03-8.77), Italy (OR = 3.47, 95% CI: 1.41-8.57), a Germanic/Slavic country (OR = 3.06, 95% CI: 1.05-8.93), or >= 2 European countries (OR = 2.82, 95% CI: 1.06-7.47); eye color-light brown (OR = 1.99, 95% CI: 1.14-3.84) and green/blue (OR = 4.62; 95% CI 2.22-9.58); pigmented lesion removal (OR = 3.78; 95% CI: 2.21-6.49); no lifetime sunscreen use (OR = 3.08; 95% CI: 1.03-9.22); and lifetime severe sunburn (OR = 1.81; 95% CI: 1.03-3.19). Conclusions: Our results indicate that European ancestry is a risk factor for cutaneous melanoma. Such risk appears to be related not only to skin type, eye color, and tanning capacity but also to others specific characteristics of European populations introduced in the New World by European immigrants.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo - FAPESP [06-52041-9, 5-56069-2]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico - Brasil (National Counsel of Technological and Scientific Development - Brazil) - CNPq [478239/03-3]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico Brasil (National Counsel of Technological and Scientific Development Brazil) CNP
Predictors of enhancing human physical attractiveness: Data from 93 countries
People across the world and throughout history have gone to great lengths to enhance their physical appearance. Evolutionary psychologists and ethologists have largely attempted to explain this phenomenon via mating preferences and strategies. Here, we test one of the most popular evolutionary hypotheses for beauty-enhancing behaviors, drawn from mating market and parasite stress perspectives, in a large cross-cultural sample. We also test hypotheses drawn from other influential and non-mutually exclusive theoretical frameworks, from biosocial role theory to a cultural media perspective. Survey data from 93,158 human participants across 93 countries provide evidence that behaviors such as applying makeup or using other cosmetics, hair grooming, clothing style, caring for body hygiene, and exercising or following a specific diet for the specific purpose of improving ones physical attractiveness, are universal. Indeed, 99% of participants reported spending >10 min a day performing beauty-enhancing behaviors. The results largely support evolutionary hypotheses: more time was spent enhancing beauty by women (almost 4 h a day, on average) than by men (3.6 h a day), by the youngest participants (and contrary to predictions, also the oldest), by those with a relatively more severe history of infectious diseases, and by participants currently dating compared to those in established relationships. The strongest predictor of attractiveness-enhancing behaviors was social media usage. Other predictors, in order of effect size, included adhering to traditional gender roles, residing in countries with less gender equality, considering oneself as highly attractive or, conversely, highly unattractive, TV watching time, higher socioeconomic status, right-wing political beliefs, a lower level of education, and personal individualistic attitudes. This study provides novel insight into universal beauty-enhancing behaviors by unifying evolutionary theory with several other complementary perspectives
Desempenho do enwatbal para avaliar a umidade do solo e o uso da água em um sistema agroflorestal
The Physiology and Proteomics of Drought Tolerance in Maize: Early Stomatal Closure as a Cause of Lower Tolerance to Short-Term Dehydration?
Understanding the response of a crop to drought is the first step in the breeding of tolerant genotypes. In our study, two maize (Zea mays L.) genotypes with contrasting sensitivity to dehydration were subjected to moderate drought conditions. The subsequent analysis of their physiological parameters revealed a decreased stomatal conductance accompanied by a slighter decrease in the relative water content in the sensitive genotype. In contrast, the tolerant genotype maintained open stomata and active photosynthesis, even under dehydration conditions. Drought-induced changes in the leaf proteome were analyzed by two independent approaches, 2D gel electrophoresis and iTRAQ analysis, which provided compatible but only partially overlapping results. Drought caused the up-regulation of protective and stress-related proteins (mainly chaperones and dehydrins) in both genotypes. The differences in the levels of various detoxification proteins corresponded well with the observed changes in the activities of antioxidant enzymes. The number and levels of up-regulated protective proteins were generally lower in the sensitive genotype, implying a reduced level of proteosynthesis, which was also indicated by specific changes in the components of the translation machinery. Based on these results, we propose that the hypersensitive early stomatal closure in the sensitive genotype leads to the inhibition of photosynthesis and, subsequently, to a less efficient synthesis of the protective/detoxification proteins that are associated with drought tolerance
Viroplasm and large virus-like particles in the dinoflagellate Gymnodinium uberrimum
Virus-like particles (VLPs) measuring 385±5 nm in diameter are described in the freshwater dinoflagellate Gymnodinium uberrimum . The VLPs are found in association with, and “budding” from a vesicular viroplasmic area. A similar viroplasm was also found in a chrysophycean alga, Mallomonas sp. collected from the same general area in Saginaw Bay of Lake Huron. The nature of these VLPs and their virogenic stroma, in these algae from the Laurentian Great Lakes are discussed in the present report.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41733/1/709_2005_Article_BF01275735.pd
Immunodiagnostic confirmation of hydatid disease in patients with a presumptive diagnosis of infection
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