208 research outputs found
Notes on the pigmentation pattern in the larval developmental stages of laboratory-reared milkfish
Milkfish fry were artificially bred and reared in the laboratory and the pigmentation pattern of the different developmental stages of the larvae are described in detail, with illustrations
Evaluating engrailed-2 and cytokines in urine with serum PSA as potential biomarkers in patients with prostatism at Moi Teaching and Referral Hospital, Eldoret, Kenya
Background: Prostatism is a clinical syndrome, occurring mostly in older men, usually caused by enlargement of the prostate gland and manifested by irritative and obstructive symptoms. Prostate cancer (CaP) is the most common non-cutaneous and the second leading cause of cancer related death in men. It is a disease in which cells in the prostate gland become abnormal and start to grow uncontrollably, forming tumours. The prostate specific antigen (PSA) test has been shown to be of low specificity and low sensitive and unable to differentiate the various forms of prostatism. Engrailed 2 and pro-inflammatory cytokines may be able to distinguish and stage protatism.Objective: To evaluate EN-2 and Cytokines in urine with serum PSA as potential biomarkers in patients with prostatism.Design: Cross sectional studySetting: Moi Teaching and Referral Hospital, Eldoret, Kenya.Subjects: Thirty nine (39) respondents were recruited in to the study. Thirteen (13) cases of prostate cancer and twenty six (26) controls were matched by age.Results: The mean age of cases was 73.1years and controls 71.1 years. Over 92.3% of the cases and 73.1% of controls had PSA values >4.0ng/ml. Both groups had elevated levels of urinary EN-2, which were statistically not significant. IL-6 and TNF-α expressions were higher in cases compared to controls with p-values of 0.0001 and 0.04 respectively. There was a good correlation between urinary IL-6 levels and urinary TNF-α levels (r=0.49)Conclusion: EN-2 expression in urine was not a predictive marker, however, IL-6 and TNF-α levels were elevated in urine of CaP patients. The potential for using these cytokines as urinary biomarkers to distinguish prostatism should be further explored
A physically based 3-D model of ice cliff evolution over debris-covered glaciers
We use high-resolution digital elevation models (DEMs) from unmanned aerial vehicle (UAV) surveys to document the evolution of four ice cliffs on the debris-covered tongue of Lirung Glacier, Nepal, over one ablation season. Observations show that out of four cliffs, three different patterns of evolution emerge: (i) reclining cliffs that flatten during the ablation season; (ii) stable cliffs that maintain a self-similar geometry; and (iii) growing cliffs, expanding laterally. We use the insights from this unique data set to develop a 3-D model of cliff backwasting and evolution that is validated against observations and an independent data set of volume losses. The model includes ablation at the cliff surface driven by energy exchange with the atmosphere, reburial of cliff cells by surrounding debris, and the effect of adjacent ponds. The cliff geometry is updated monthly to account for the modifications induced by each of those processes. Model results indicate that a major factor affecting the survival of steep cliffs is the coupling with ponded water at its base, which prevents progressive flattening and possible disappearance of a cliff. The radial growth observed at one cliff is explained by higher receipts of longwave and shortwave radiation, calculated taking into account atmospheric fluxes, shading, and the emission of longwave radiation from debris surfaces. The model is a clear step forward compared to existing static approaches that calculate atmospheric melt over an invariant cliff geometry and can be used for long-term simulations of cliff evolution and to test existing hypotheses about cliffs' survival
On divergent 3-vertices in noncommutative SU(2)gauge theory
We analyze divergencies in 2-point and 3-point functions for noncommutative
-expanded SU(2)-gauge theory with massless fermions. We show that,
after field redefinition and renormalization of couplings, one divergent term
remains.Comment: 7 page
Learning from model errors: Can land use, edaphic and very high-resolution topo-climatic factors improve macroecological models of mountain grasslands?
Aim: Assess the potential of new predictors (land use, edaphic factors and high-resolution topographic and climatic variables, i.e., topo-climatic) to improve the prediction of plant community functional traits (specific leaf area, vegetative height and seed mass) and species richness in models of mountain grasslands.
Location: The western Swiss Alps
Methods: Using 912 grassland plots, we constructed predictive models for community-weighted means of plant traits and species richness using high resolution (25 m) topo-climatic predictors traditionally used in previous modelling studies in this area. In addition, 78 new plots were sampled for evaluation and error assessment in four narrower sets of homogenous conditions based on predictions by the topo-climatic models within two elevation belts (montane and alpine). New, finer-scale predictors were generated from direct field measurements or very high-resolution (5 m) numerical data. We then used multimodel inference to test the capacity of these finer predictors to explain part of the residual variance in the initial topo-climatic models.
Results: We showed that the finer-scale predictors explained up to 44% of the residual variance in the classical topo-climatic models. The very high-resolution topographic position, soil C/N ratio and pH performed notably well in our analysis. Land use (farming intensity) was highlighted as potentially important in montane grasslands, but improvements were only significant for species richness predictions.
Main conclusions: Compared with classical topo-climatic models, the new, finer-scale predictors significantly improved the prediction of all traits and species richness in alpine plant communities and that of specific leaf area and richness in montane grasslands. The differences in the importance of the predictors, dependent on both trait and position along the elevation gradient, highlight the different factors that shape the distribution of species and communities along elevation gradients
Spatial modelling of soil water holding capacity improves models of plant distributions in mountain landscapes
Aims
The aims of this study were: 1) to test a new methodology to overcome the issue of the predictive capacity of soil water availability in geographic space due to measurement scarcity, 2) to model and generalize soil water availability spatially to a whole region, and 3) to test its predictive capacity in plant SDMs.
Methods
First, we modelled the measured Soil Water Holding Capacity (SWHC at different pFs) of 24 soils in a focal research area, using a weighted ensemble of small bivariate models (ESM). We then used these models to predict 256 locations of a larger region and used the differences in these pF predictions to calculate three different indices of soil water availability for plants (SWAP. These SWAP variables were added one by one to a set of conventional topo-climatic predictors to model 104 plant species distributions.
Results
We showed that adding SWAP to the SDMs could improve our ability to predict plant species distributions, and more specifically, pF1.8–pF4.2 became the third most important predictor across all plant models.
Conclusions
Soil water availability can contribute a significant increase in the predictive power of plant distribution models, by identifying important additional abiotic information to describe plant ecological niches
Explorando las Aulas de Clase de Inglés en Cañar: Currículo, instrucción y aprendizaje.//Exploring the English language classrooms in Cañar: Curriculum, instruction and learning.
La presente investigación tiene como propósito conocer cómo se lleva a cabo la enseñanza y aprendizaje del inglés en el marco del currículo actual en el último año de Bachillerato General Unificado (BGU) de ocho unidades educativas públicas y rurales en un cantón de la provincia de Cañar. En primer lugar, se determinó el nivel de suficiencia de inglés de los estudiantes de BGU, lo cual también permitió conocer en qué competencias lingüísticas existen mayores y menores dificultades. Luego se realizaron observaciones directas para identificar cómo la enseñanza del inglés se lleva cabo en las aulas de clase. Del mismo modo, grupos focales y entrevistas fueron realizados para conocer los puntos de vista de los estudiantes y de ocho profesores acerca de aspectos claves de la asignatura de inglés. Los resultados indicaron que los estudiantes tienen un bajo nivel de suficiencia y que en gran medida la enseñanza no está alineada al currículo de inglés. Para finalizar, se obtuvo que los estudiantes tienen puntos de vista positivos sobre el aprendizaje del inglés, resaltando la utilidad e importancia de este idioma, del mismo modo, para los docentes representa un reto la implementación del enfoque metodológico de enseñanza incorporado en el currículo, por ello, necesario medidas efectivas para mejorar la educación pública en inglés. AbstractThe purpose of this research is to find out how the teaching and learning of English is carried out within the framework of the current curriculum in the last year of the Unified General Baccalaureate (BGU) of eight public and rural educational units in a canton in the province of Cañar. In the first place, the level of English proficiency of the BGU students was determined, which also made it possible to know in which language skills there are greater and lesser difficulties. Direct observations were then made to identify how English is taught in classrooms. Similarly, focus groups and interviews were conducted to hear the views of students and eight teachers on key aspects of the English subject. The results indicated that the students have a low level of proficiency and that to a large extent the teaching is not aligned with the English curriculum. To conclude, it was obtained that the students have positive points of view on learning English, highlighting the usefulness and importance of this language, in the same way, for the teachers it represents a challenge to implement the methodological approach of teaching incorporated in the curriculum, for that reason, effective measures are necessary to improve public education in English
Near-extremal and extremal quantum-corrected two-dimensional charged black holes
We consider charged black holes within dilaton gravity with
exponential-linear dependence of action coefficients on dilaton and minimal
coupling to quantum scalar fields. This includes, in particular, CGHS and RST
black holes in the uncharged limit. For non-extremal configuration quantum
correction to the total mass, Hawking temperature, electric potential and
metric are found explicitly and shown to obey the first generalized law. We
also demonstrate that quantum-corrected extremal black holes in these theories
do exist and correspond to the classically forbidden region of parameters in
the sense that the total mass ( is a charge). We show that in
the limit (where is the Hawking temperature) the mass and
geometry of non-extremal configuration go smoothly to those of the extremal
one, except from the narrow near-horizon region. In the vicinity of the horizon
the quantum-corrected geometry (however small quantum the coupling parameter
would be) of a non-extremal configuration tends to not the
quantum-corrected extremal one but to the special branch of solutions with the
constant dilaton (2D analog of the Bertotti-Robinson metric) instead.
Meanwhile, if exactly, the near-extremal configuration tends to the
extremal one. We also consider the dilaton theory which corresponds classically
to the spherically-symmetrical reduction from 4D case and show that for the
quantum-corrected extremal black hole .Comment: 25 pages. Typos corrected. To appear in Class. Quant. Gra
Supraglacial debris thickness and supply rate in High-Mountain Asia
Supraglacial debris strongly modulates glacier melt rates and can be decisive for ice dynamics and mountain hydrology. It is ubiquitous in High-Mountain Asia, yet because its thickness and supply rate from local topography are poorly known, our ability to forecast regional glacier change and streamflow is limited. Here we combined remote sensing and numerical modelling to resolve supraglacial debris thickness by altitude for 4689 glaciers in High-Mountain Asia, and debris-supply rate to 4141 of those glaciers. Our results reveal extensively thin supraglacial debris and high spatial variability in both debris thickness and supply rate. Debris-supply rate increases with the temperature and slope of debris-supply slopes regionally, and debris thickness increases as ice flow decreases locally. Our centennial-scale estimates of debris-supply rate are typically an order of magnitude or more lower than millennial-scale estimates of headwall-erosion rate from Beryllium-10 cosmogenic nuclides, potentially reflecting episodic debris supply to the region’s glaciers
Controls on the relative melt rates of debris-covered glacier surfaces
Supraglacial debris covers 7% of mountain glacier area globally and generally reduces glacier surface melt. Enhanced energy absorption at ice cliffs and supraglacial ponds scattered across the debris surface leads these features to contribute disproportionately to glacier-wide ablation. However, the degree to which cliffs and ponds actually increase melt rates remains unclear, as these features have only been studied in a detailed manner for selected locations, almost exclusively in High Mountain Asia. In this study we model the surface energy balance for debris-covered ice, ice cliffs, and supraglacial ponds with a set of automatic weather station records representing the global prevalence of debris-covered glacier ice. We generate 5000 random sets of values for physical parameters using probability distributions derived from literature, which we use to investigate relative melt rates and to isolate the melt responses of debris, cliffs and ponds to the site-specific meteorological forcing. Modelled sub-debris melt rates are primarily controlled by debris thickness and thermal conductivity. At a reference thickness of 0.1 m, sub-debris melt rates vary considerably, differing by up to a factor of four between sites, mainly attributable to air temperature differences. We find that melt rates for ice cliffs are consistently 2–3× the melt rate for clean glacier ice, but this melt enhancement decays with increasing clean ice melt rates. Energy absorption at supraglacial ponds is dominated by latent heat exchange and is therefore highly sensitive to wind speed and relative humidity, but is generally less than for clean ice. Our results provide reference melt enhancement factors for melt modelling of debris-covered glacier sites, globally, while highlighting the need for direct measurement of debris-covered glacier surface characteristics, physical parameters, and local meteorological conditions at a variety of sites around the world
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