DISEÑO DE ZANJAS CON VELOCIDAD DE INFILTRACIÓN VARIABLE PARA CONSERVACIÓN DE AGUAS Y SUELOS DE LA CUENCA DEL RÍO PURAPEL (CHILE)

Se desarrolló un procedimiento para dimensionar zanjas de infiltración dependiendo de un balance hídrico en la ladera, el cual está focalizado en dos elementos centrales; eventos extremos de precipitación y capacidad de infiltración variable. Este modelo de infiltración incorpora el análisis regional de frecuencia, técnicas geoestadísticas, la ecuación de infiltración de Green- Ampt para superficies con pendientes y un modelo de balance hídrico propuesto por Akan (2002). Los resultados del modelo de zanjas de infiltración con tasas variables de infiltración y diferentes texturas del suelo, permitieron obtener mediante métodos numéricos, los parámetros de diseño de una zanja: altura máxima de agua (calado) y el tiempo de almacenamiento. Este estudio proporciona una extensión práctica de las relaciones intensidad-duración frecuencia para zonas sin registro continuo de la lluvia y con escasez de datos hidrológicos y climatológicos, con el propósito de dimensionar estructuras de conservación de aguas y suelo. El modelo fue aplicado a la cuenca del Río Purapel en Chile central, para demostrar la facilidad del procedimiento sugerido

Effect of Melengestrol Acetate (Mga) on the Metabolic Profile in Heifers

AbstractFrom the analysis of 21 Cebu-Swiss heifers healthy, developing, with 235.55 ± 17.81kg of body weight (BW), 118.62 ± 3.97cm and 2.58 ± 0.35 of body condition (BC) scale of 1-5. They were divided into two groups: MGA (n = 10) and control (n = 11). For 55 days were given a constant diet (including 15 days of adaptation), based on concentrate and sorghum straw. The contribution of daily intake was 599.08g of crude protein and 12.18 Mcal. Blood samples were obtained every 5 days. The concentrations of cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein, urea, total protein and glucose were measured for spectrophotometric using the enzyme-colorimetric technique in plasma. The daily gain was balanced PV of 603.5 to 232.5 grams and height stopped from day 25. The CC did not show significant changes (P> 0.01). The mean concentration of plasma cholesterol was 107.59 ± 13.38 vs. 109.61 ± 11.72mg/dl (MGA and control, respectively) with a downward trend more pronounced from day 25. The concentration of triglycerides was 12.61 ± 6.91 vs. 16.19 ± 8.86mg/dl (MGA and control), no trend in the first 20 days and from day 25 there was an increase compared to the average of the previous days. The concentrations of HDL 63.73 ± 3.26 vs. 63.79 ± 10.27mg/dl (MGA and control) and 43.56 ± 6.24 vs. LDLc. 46.54 ± 14.89mg/dl (MGA and control) were irregular, but within normal ranges. The values of total protein were 5.70 ± 0.40 vs. 5.22 ± 0.31mg/dl (MGA and control), no trend the first 15 days and from day 20 increased in concentration compared to previous surveys. Urea levels were 14.79 ± 5.22 vs. 14.13 ± 4.8mg/dl (MGA and control) with a tendency to discharge. Glucose levels were 60.06 ± 7.62 vs. 58.24 ± 5.43mg/dl (MGA and control), with an irregular behavior in the normal range. The consumption of 0.5mg/dl of MGA for 40 days increased plasma concentrations of triglycerides and total protein, but did not affect cholesterol levels, HDL and LDL cholesterol, urea and glucose

Intrinsic decoherence and classical-quantum correspondence in two coupled delta-kicked rotors

We show that classical-quantum correspondence of center of mass motion in two coupled delta-kicked rotors can be obtained from intrinsic decoherence of the system itself which occurs due to the entanglement of the center of mass motion to the internal degree of freedom without coupling to external environment

Microfluidic-based immunohistochemistry for breast cancer diagnosis: a comparative clinical study.

Breast cancer is a highly heterogeneous disease. The efficacy of tailored therapeutic strategies relies on the precise detection of diagnostic biomarkers by immunohistochemistry (IHC). Therefore, considering the increasing incidence of breast cancer cases, a concomitantly time-efficient and accurate diagnosis is clinically highly relevant. Microfluidics is a promising innovative technology in the field of tissue diagnostic, enabling for rapid, reliable, and automated immunostaining. We previously reported the microfluidic-based HER2 (human epidermal growth factor receptor 2) detection in breast carcinomas to greatly correlate with the HER2 gene amplification level. Here, we aimed to develop a panel of microfluidic-based IHC protocols for prognostic and therapeutic markers routinely assessed for breast cancer diagnosis, namely HER2, estrogen/progesterone receptor (ER/PR), and Ki67 proliferation factor. The microfluidic IHC protocol for each marker was optimized to reach high staining quality comparable to the standard procedure, while concomitantly shortening the staining time to 16 min-excluding deparaffinization and antigen retrieval step-with a turnaround time reduction up to 7 folds. Comparison of the diagnostic score on 50 formaldehyde-fixed paraffin-embedded breast tumor resections by microfluidic versus standard staining showed high concordance (overall agreement: HER2 94%, ER 95.9%, PR 93.6%, Ki67 93.7%) and strong correlation (ρ coefficient: ER 0.89, PR 0.88, Ki67 0.87; p < 0.0001) for all the analyzed markers. Importantly, HER2 genetic reflex test for all discordant cases confirmed the scores obtained by the microfluidic technique. Overall, the microfluidic-based IHC represents a clinically validated equivalent approach to the standard chromogenic staining for rapid, accurate, and automated breast cancer diagnosis

Killing spectroscopy of closed timelike curves

We analyse the existence of closed timelike curves in spacetimes which possess an isometry. In particular we check which discrete quotients of such spaces lead to closed timelike curves. As a by-product of our analysis, we prove that the notion of existence or non-existence of closed timelike curves is a T-duality invariant notion, whenever the direction along which we apply such transformations is everywhere spacelike. Our formalism is straightforwardly applied to supersymmetric theories. We provide some new examples in the context of D-branes and generalized pp-waves.Comment: 1+35 pages, no figures; v2, new references added. Final version to appear in JHE

Functional characterization of a melon alcohol acyl-transferase gene family involved in the biosynthesis of ester volatiles. Identification of the crucial role of a threonine residue for enzyme activity

Volatile esters, a major class of compounds contributing to the aroma of many fruit, are synthesized by alcohol acyl-transferases (AAT). We demonstrate here that, in Charentais melon (Cucumis melo var. cantalupensis), AAT are encoded by a gene family of at least four members with amino acid identity ranging from 84% (Cm-AAT1/Cm-AAT2) and 58% (Cm-AAT1/Cm-AAT3) to only 22% (Cm-AAT1/Cm-AAT4). All encoded proteins, except Cm-AAT2, were enzymatically active upon expression in yeast and show differential substrate preferences. Cm-AAT1 protein produces a wide range of short and long-chain acyl esters but has strong preference for the formation of E-2-hexenyl acetate and hexyl hexanoate. Cm-AAT3 also accepts a wide range of substrates but with very strong preference for producing benzyl acetate. Cm-AAT4 is almost exclusively devoted to the formation of acetates, with strong preference for cinnamoyl acetate. Site directed mutagenesis demonstrated that the failure of Cm-AAT2 to produce volatile esters is related to the presence of a 268-alanine residue instead of threonine as in all active AAT proteins. Mutating 268-A into 268-T of Cm-AAT2 restored enzyme activity, while mutating 268-T into 268-A abolished activity of Cm-AAT1. Activities of all three proteins measured with the prefered substrates sharply increase during fruit ripening. The expression of all Cm-AAT genes is up-regulated during ripening and inhibited in antisense ACC oxidase melons and in fruit treated with the ethylene antagonist 1-methylcyclopropene (1-MCP), indicating a positive regulation by ethylene. The data presented in this work suggest that the multiplicity of AAT genes accounts for the great diversity of esters formed in melon

Criticality in confined ionic fluids

A theory of a confined two dimensional electrolyte is presented. The positive and negative ions, interacting by a $1/r$ potential, are constrained to move on an interface separating two solvents with dielectric constants $\epsilon_1$ and $\epsilon_2$. It is shown that the Debye-H\"uckel type of theory predicts that the this 2d Coulomb fluid should undergo a phase separation into a coexisting liquid (high density) and gas (low density) phases. We argue, however, that the formation of polymer-like chains of alternating positive and negative ions can prevent this phase transition from taking place.Comment: RevTex, no figures, in press Phys. Rev.

Freezing in the Sun

When the air is very cold, water at the surface of the ocean freezes, forming sea ice. Parts of the Arctic Ocean are covered by sea ice during the entire year. Often, snow falls onto the sea ice. Despite the cold, many plants and animals can live in the Arctic Ocean, some in the water, and some even in the sea ice. Particularly, algae can live in small bubbles in the sea ice. Like other plants, algae need energy to grow. This energy comes from food and sunlight. But how can the sunlight reach these little algae living inside the sea ice? From the sun, the light must pass through the atmosphere, the snow, and finally the sea ice itself. In this article, we describe how ice algae can live in this special environment and we explain what influences how much light reaches the algae to make them grow

Development of a planar multi-body model of the human knee joint

The aim of this work is to develop a dynamic model for the biological human knee joint. The model is formulated in the framework of multibody systems methodologies, as a system of two bodies, the femur and the tibia. For the purpose of describing the formulation, the relative motion of the tibia with respect to the femur is considered. Due to their higher stiffness compared to that of the articular cartilages, the femur and tibia are considered as rigid bodies. The femur and tibia cartilages are considered to be deformable structures with specific material characteristics. The rotation and gliding motions of the tibia relative to the femur can not be modeled with any conventional kinematic joint, but rather in terms of the action of the knee ligaments and potential contact between the bones. Based on medical imaging techniques, the femur and tibia profiles in the sagittal plane are extracted and used to define the interface geometric conditions for contact. When a contact is detected, a continuous non-linear contact force law is applied which calculates the contact forces developed at the interface as a function of the relative indentation between the two bodies. The four basic cruciate and collateral ligaments present in the knee are also taken into account in the proposed knee joint model, which are modeled as non-linear elastic springs. The forces produced in the ligaments, together with the contact forces, are introduced into the system’s equations of motion as external forces. In addition, an external force is applied on the center of mass of the tibia, in order to actuate the system mimicking a normal gait motion. Finally, numerical results obtained from computational simulations are used to address the assumptions and procedures adopted in this study.Fundação para a Ciência e a Tecnologia (FCT