407 resultados para Rana latouchii


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This study investigated how harvest and water management affected the ecology of the Pig Frog, Rana grylio. It also examined how mercury levels in leg muscle tissue vary spatially across the Everglades. Rana grylio is an intermediate link in the Everglades food web. Although common, this inconspicuous species can be affected by three forms of anthropogenic disturbance: harvest, water management and mercury contamination. This frog is harvested both commercially and recreationally for its legs, is aquatic and thus may be susceptible to water management practices, and can transfer mercury throughout the Everglades food web. ^ This two-year study took place in three major regions: Everglades National Park (ENP), Water Conservation Areas 3A (A), and Water Conservation Area 3B (B). The study categorized the three sites by their relative harvest level and hydroperiod. During the spring of 2001, areas of the Everglades dried completely. On a regional and local scale Pig Frog abundance was highest in Site A, the longest hydroperiod, heavily harvested site, followed by ENP and B. More frogs were found along survey transects and in capture-recapture plots before the dry-down than after the dry-down in Sites ENP and B. Individual growth patterns were similar across all sites, suggesting differences in body size may be due to selective harvest. Frogs from Site A, the flooded and harvested site, had no differences in survival rates between adults and juveniles. Site B populations shifted from a juvenile to adult dominated population after the dry-down. Dry-downs appeared to affect survival rates more than harvest. ^ Total mercury in frog leg tissue was highest in protected areas of Everglades National Park with a maximum concentration of 2.3 mg/kg wet mass where harvesting is prohibited. Similar spatial patterns in mercury levels were found among pig frogs and other wildlife throughout parts of the Everglades. Pig Frogs may be transferring substantial levels of mercury to other wildlife species in ENP. ^ In summary, although it was found that abundance and survival were reduced by dry-down, lack of adult size classes in Site A, suggest harvest also plays a role in regulating population structure. ^

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The skin is one of the largest organs of the human body and accounts for about 16% of body weight. The body protection against the external environment microorganisms is one of its most important functions, however is necessary that the skin remain intact for this function be exercised, so that when there is an injury on the skin, the process of restructuring needs to be starts, however this restructuration may also be compromised due to some diseases, justifying even more the need for the development of topical products that promote or accelerate the skin healing. Thus the aim of this study was to extract bullfrog oil and to develop a suitable topical emulsion. Two different oil samples were extracted by hot or organic solvent process. Titration techniques and gas chromatography- mass spectrometry were used to characterize the bullfrog oil. The required hydrophile-lipophile balance (HLBr) of bullfrog oil was determined and a pseudo-ternary phase diagram was constructed. The stability of the topical emulsion was evaluated. Then, cellular viability was determined by MTT assay using normal fibroblasts (3T3) and melanoma (B16F10) cells lines. The hot extraction yield was 60.6%. The major polyunsaturated compounds found were Eicosapentaenoic acid (17.6%) and Arachidonic acid (8.4%). HLBr study demonstrated the presence of stable systems with HLB ranging from 12.1 to 13.5 and the pseudo-ternary phase diagram showed mainly emulsion systems (62%). Topical emulsion showed 390 nm, polydispersity 0.05, zeta potential -25 mV and remained stable for ninety days. The bullfrog oil and topical emulsion did not showed citotoxicity in normal fibroblasts cells. However, these systems showed significantly inhibition of melanoma cells growth. In conclusion, the bullfrog oil presented desirable chemical characteristics required to be used for the development of a pharmaceutical and cosmetic products.

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Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

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Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

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Ranas clasificadas como ranas pipiens representan a un grupo de especies relacionadas. En este trabajo se compararon cuatro poblaciones de este grupo viviendo en Costa Rica en alturas y en medios ambientes diferentes en cuanto a morfología y compatibilidad reproductiva. No existe una diferencia significativa entre la forma del rostro en las poblaciones estudiadas, pero al tamaño promedio de ambos sexos disminuye a un “cline” (grado) con incremento de altura. Cruces artificiales indican una reducción significativa en la compatibilidad reproductiva entre la población más alta y las más bajas. Se propone que el cambio clinal en tamaño y la incompatibilidad reproductiva de la población alta representa una divergencia genética y posiblemente una especie nueva en proceso de formación. Se propone también que una “especiación” parecida pueda estar ocurriendo en otras montañas y volcanes de América Central en varios grupos de organismos.

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Se estudiaron veinticuatro ejemplares de la rana neotropical rana palmipes spix, con el fin de conocer si una población de ranas que habita en aguas de contenido de cloruro de sodio mayor que el normal poseen una habilidad mas alta para concentrar sal, que una población que habita en agua de menor concentración. Las normalidades del agua en los dos sitios de colección tuvieron valores muy próximas para llegar a conclusiones definitivas. Sin embargo, en base de la información obtenida, se concluye que las ranas que viven en el agua de salinidad mas alta están eliminando orina con un contenido de sal parecido a las ranas que viven en agua mas dulce, y que por eso se supone que las ranas que viven en agua de mayor salinidad puedan eliminar mas orina por unidad del tamaño del cuerpo.

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The objective of this experiment was to evaluate the inclusion of meal of tilapia industrial waster in bullfrog tadpoles' diets (Rana Catesbeina Shaw, 1802). Two hundred fifty tadpoles with initial weight and length of 0,18 +/- 0,05g and 2,50 +/- 0,18 centimeters were used, respectively, they were used and distributed in 25 aquariums of 30 liter each in a complete randomized design with five treatments and five repetitions. The tadpoles were fed four times a day with diets containing 0, 5, 10 and 15% of inclusion of tilapia filleting and another diet with 0% of supplemented tilapia filleting with synthetic methionine, being supplied four times a day at ease. The experiment period was 30 days. The diets with tilapia filleting inclusion and methionine supplementation did not have influence in the final weight and length averages, feed survival and conversion of bullfrog tadpoles. It cam be used until 15% of tilapia filleting inclusion in the bullfrog tadpoles food. The synthetic methionine supplementation in diets for bullfrog tadpoles is not necessary in diets with levels over 0,471/4 of the total methionine.

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The Lernaea cyprinacea Linnaeus, 1758 copepodids experimental contamination on the Rana catesbeiana Shaw, 1802 ladpoles was analized. Sixty percent (12) of infested tadpoles was found parasitized. High mortality range, lower appetence, equilibrium loss and apathy were observed. The parasites showed the preference for the mouth and cloaca: in 72 hours lhe egg saes had already developed.

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Unusual event detection in crowded scenes remains challenging because of the diversity of events and noise. In this paper, we present a novel approach for unusual event detection via sparse reconstruction of dynamic textures over an overcomplete basis set, with the dynamic texture described by local binary patterns from three orthogonal planes (LBPTOP). The overcomplete basis set is learnt from the training data where only the normal items observed. In the detection process, given a new observation, we compute the sparse coefficients using the Dantzig Selector algorithm which was proposed in the literature of compressed sensing. Then the reconstruction errors are computed, based on which we detect the abnormal items. Our application can be used to detect both local and global abnormal events. We evaluate our algorithm on UCSD Abnormality Datasets for local anomaly detection, which is shown to outperform current state-of-the-art approaches, and we also get promising results for rapid escape detection using the PETS2009 dataset.

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In automatic facial expression recognition, an increasing number of techniques had been proposed for in the literature that exploits the temporal nature of facial expressions. As all facial expressions are known to evolve over time, it is crucially important for a classifier to be capable of modelling their dynamics. We establish that the method of sparse representation (SR) classifiers proves to be a suitable candidate for this purpose, and subsequently propose a framework for expression dynamics to be efficiently incorporated into its current formulation. We additionally show that for the SR method to be applied effectively, then a certain threshold on image dimensionality must be enforced (unlike in facial recognition problems). Thirdly, we determined that recognition rates may be significantly influenced by the size of the projection matrix \Phi. To demonstrate these, a battery of experiments had been conducted on the CK+ dataset for the recognition of the seven prototypic expressions - anger, contempt, disgust, fear, happiness, sadness and surprise - and comparisons have been made between the proposed temporal-SR against the static-SR framework and state-of-the-art support vector machine.

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Compressive Sensing (CS) is a popular signal processing technique, that can exactly reconstruct a signal given a small number of random projections of the original signal, provided that the signal is sufficiently sparse. We demonstrate the applicability of CS in the field of gait recognition as a very effective dimensionality reduction technique, using the gait energy image (GEI) as the feature extraction process. We compare the CS based approach to the principal component analysis (PCA) and show that the proposed method outperforms this baseline, particularly under situations where there are appearance changes in the subject. Applying CS to the gait features also avoids the need to train the models, by using a generalised random projection.

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Marketers spend considerable resources to motivate people to consume their products and services as a means of goal attainment (Bagozzi and Dholakia, 1999). Why people increase, decrease, or stop consuming some products is based largely on how well they perceive they are doing in pursuit of their goals (Carver and Scheier, 1992). Yet despite the importance for marketers in understanding how current performance influences a consumer’s future efforts, this topic has received little attention in marketing research. Goal researchers generally agree that feedback about how well or how poorly people are doing in achieving their goals affects their motivation (Bandura and Cervone, 1986; Locke and Latham, 1990). Yet there is less agreement about whether positive and negative performance feedback increases or decreases future effort (Locke and Latham, 1990). For instance, while a customer of a gym might cancel his membership after receiving negative feedback about his fitness, the same negative feedback might cause another customer to visit the gym more often to achieve better results. A similar logic can apply to many products and services from the use of cosmetics to investing in mutual funds. The present research offers managers key insights into how to engage customers and keep them motivated. Given that connecting customers with the company is a top research priority for managers (Marketing Science Institute, 2006), this article provides suggestions for performance metrics including four questions that managers can use to apply the findings.

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We show that imatinib, nilotinib, and dasatinib possess weak off-target activity against RAF and, therefore, drive paradoxical activation of BRAF and CRAF in a RAS-dependent manner. Critically, because RAS is activated by BCR-ABL, in drug-resistant chronic myeloid leukemia (CML) cells, RAS activity persists in the presence of these drugs, driving paradoxical activation of BRAF, CRAF, MEK, and ERK, and leading to an unexpected dependency on the pathway. Consequently, nilotinib synergizes with MEK inhibitors to kill drug-resistant CML cells and block tumor growth in mice. Thus, we show that imatinib, nilotinib, and dasatinib drive paradoxical RAF/MEK/ERK pathway activation and have uncovered a synthetic lethal interaction that can be used to kill drug-resistant CML cells in vitro and in vivo.

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Background The Global Burden of Disease Study 2013 (GBD 2013) aims to bring together all available epidemiological data using a coherent measurement framework, standardised estimation methods, and transparent data sources to enable comparisons of health loss over time and across causes, age–sex groups, and countries. The GBD can be used to generate summary measures such as disability-adjusted life-years (DALYs) and healthy life expectancy (HALE) that make possible comparative assessments of broad epidemiological patterns across countries and time. These summary measures can also be used to quantify the component of variation in epidemiology that is related to sociodemographic development. Methods We used the published GBD 2013 data for age-specific mortality, years of life lost due to premature mortality (YLLs), and years lived with disability (YLDs) to calculate DALYs and HALE for 1990, 1995, 2000, 2005, 2010, and 2013 for 188 countries. We calculated HALE using the Sullivan method; 95% uncertainty intervals (UIs) represent uncertainty in age-specific death rates and YLDs per person for each country, age, sex, and year. We estimated DALYs for 306 causes for each country as the sum of YLLs and YLDs; 95% UIs represent uncertainty in YLL and YLD rates. We quantified patterns of the epidemiological transition with a composite indicator of sociodemographic status, which we constructed from income per person, average years of schooling after age 15 years, and the total fertility rate and mean age of the population. We applied hierarchical regression to DALY rates by cause across countries to decompose variance related to the sociodemographic status variable, country, and time. Findings Worldwide, from 1990 to 2013, life expectancy at birth rose by 6·2 years (95% UI 5·6–6·6), from 65·3 years (65·0–65·6) in 1990 to 71·5 years (71·0–71·9) in 2013, HALE at birth rose by 5·4 years (4·9–5·8), from 56·9 years (54·5–59·1) to 62·3 years (59·7–64·8), total DALYs fell by 3·6% (0·3–7·4), and age-standardised DALY rates per 100 000 people fell by 26·7% (24·6–29·1). For communicable, maternal, neonatal, and nutritional disorders, global DALY numbers, crude rates, and age-standardised rates have all declined between 1990 and 2013, whereas for non–communicable diseases, global DALYs have been increasing, DALY rates have remained nearly constant, and age-standardised DALY rates declined during the same period. From 2005 to 2013, the number of DALYs increased for most specific non-communicable diseases, including cardiovascular diseases and neoplasms, in addition to dengue, food-borne trematodes, and leishmaniasis; DALYs decreased for nearly all other causes. By 2013, the five leading causes of DALYs were ischaemic heart disease, lower respiratory infections, cerebrovascular disease, low back and neck pain, and road injuries. Sociodemographic status explained more than 50% of the variance between countries and over time for diarrhoea, lower respiratory infections, and other common infectious diseases; maternal disorders; neonatal disorders; nutritional deficiencies; other communicable, maternal, neonatal, and nutritional diseases; musculoskeletal disorders; and other non-communicable diseases. However, sociodemographic status explained less than 10% of the variance in DALY rates for cardiovascular diseases; chronic respiratory diseases; cirrhosis; diabetes, urogenital, blood, and endocrine diseases; unintentional injuries; and self-harm and interpersonal violence. Predictably, increased sociodemographic status was associated with a shift in burden from YLLs to YLDs, driven by declines in YLLs and increases in YLDs from musculoskeletal disorders, neurological disorders, and mental and substance use disorders. In most country-specific estimates, the increase in life expectancy was greater than that in HALE. Leading causes of DALYs are highly variable across countries. Interpretation Global health is improving. Population growth and ageing have driven up numbers of DALYs, but crude rates have remained relatively constant, showing that progress in health does not mean fewer demands on health systems. The notion of an epidemiological transition—in which increasing sociodemographic status brings structured change in disease burden—is useful, but there is tremendous variation in burden of disease that is not associated with sociodemographic status. This further underscores the need for country-specific assessments of DALYs and HALE to appropriately inform health policy decisions and attendant actions.