Multiple-Input Multiple-Output Gaussian Broadcast Channels with Common and Confidential Messages

This paper considers the problem of the multiple-input multiple-output (MIMO) Gaussian broadcast channel with two receivers (receivers 1 and 2) and two messages: a common message intended for both receivers and a confidential message intended only for receiver 1 but needing to be kept asymptotically perfectly secure from receiver 2. A matrix characterization of the secrecy capacity region is established via a channel enhancement argument. The enhanced channel is constructed by first splitting receiver 1 into two virtual receivers and then enhancing only the virtual receiver that decodes the confidential message. The secrecy capacity region of the enhanced channel is characterized using an extremal entropy inequality previously established for characterizing the capacity region of a degraded compound MIMO Gaussian broadcast channel.Comment: Submitted to the IEEE Transactions on Information Theory, July 200

Cell death caused by single-stranded oligodeoxynucleotide-mediated targeted genomic sequence modification

Targeted gene repair directed by single-stranded oligodeoxynucleotides (ssODNs) offers a promising tool for biotechnology and gene therapy. However, the methodology is currently limited by its low frequency of repair events, variability, and low viability of "corrected" cells. In this study, we showed that during ssODN-mediated gene repair reaction, a significant population of corrected cells failed to divide, and were much more prone to undergo apoptosis, as marked by processing of caspases and PARP-1. In addition, we found that apoptotic cell death triggered by ssODN-mediated gene repair was largely independent of the ATM/ATR kinase. Furthermore, we examined the potential involvement of the mismatch repair (MMR) proteins in this "correction reaction-induced" cell death. Result showed that while defective MMR greatly enhanced the efficiency of gene correction, compromising the MMR system did not yield any viable corrected clone, indicating that the MMR machinery, although plays a critical role in determining ssODN-directed repair, was not involved in the observed cellular genotoxic responses. © 2009. Mary Ann Liebert, Inc.published_or_final_versio

Microfluidic E. coli Detection

In both developed and developing countries, there is a need for a fast diagnostic system to detect pathogens within a fluid sample. In developing a microfluidic platform, which utilizes a microfluidic chip and an optical detection method, doors may be opened for new methods of determining pathogen concentration in fluid. Most biological reactions are not instantaneous. A flow-controlling mechanism with no power requirement may be implemented in the microfluidic platform. As a proof-of-concept, our device uses a microfluidic chip, smartphone, and microlens to detect E. coli concentrations in water. The detection method is based on the latex agglutination assay which relies on visual observations and judgment to determine the presence of pathogens in the water sample. Our approach provides a quantification of the traditional latex agglutination output, and the lower detection limit (105cells/mL) is competitive with that of the traditional agglutination method. In developing such a platform, a cheap and effective detection test for people in developing countries can be available worldwide for easy determination of whether or not a fluid sample is safe for use, and with several modifications, this platform could potentially be used to detect different pathogens, simultaneously

Prevalencia de niveles bajos de vitamina D y síndrome metabólico en pacientes que acuden a consulta en un Hospital de tercer nivel

La vitamina D está involucrada en procesos biológicos más allá de su clásico papel en la homeostasis del hueso. Actualmente, se está dando cada vez más importancia a su función en la fisiopatogénesis de las alteraciones metabólicas que afectan a la adiposidad y a la alteración del control glucémico y a los factores de riesgo cardiovascular (FRCV). Este hecho se traduce clínicamente en que unos niveles bajos de vitamina D podrían estar relacionados con un aumento en la prevalencia de síndrome metabólico (SM) y la presencia de enfermedades cardiovasculares (ECAV). Teniendo en cuenta que las ECAV suponen la principal causa de muerte a nivel global, según la Organización Mundial de la Salud, sería de vital importancia poder detectar a la población más susceptible de desarrollar estas enfermedades para poder realizar medidas de prevención y tratamiento en caso necesario. En este trabajo se va a estudiar la relación entre los niveles bajos de vitamina D con el SM y las ECAV en pacientes que acuden a acuden a la consulta del Servicio de Endocrinología del Hospital Ramón y Cajal. Se trata de un estudio descriptivo transversal, realizado con datos recogidos entre marzo 2015 y mayo 2017. La población estudiada presenta una deficiencia generalizada de vitamina D, deficiencia que depende de factores como sexo, edad, estacionalidad, así como de la presencia de diversas ECAV y sus marcadores fisiopatológicos. Existe una relación entre la presencia de niveles bajos de vitamina D y el SM. Casi la mitad de la muestra (el 49%) presentaba déficit de vitamina D y el 53% tenía SM. Los pacientes con SM presentaban valores medios de vitamina D significativamente más bajos que aquellos que no tenían SM. El fenotipo del SM en nuestro trabajo muestra como factores más prevalentes por orden de frecuencia: la disminución del colesterol HDL, seguido por la elevación de la glucemia, los triglicéridos, el incremento del perímetro de la cintura y la elevación de la presión arterial. Por lo que el abordaje terapéutico y nutricional de estos componentes junto con una elevación de la vitamina D supondrían una disminución en la prevalencia del SM. La asociación del déficit de vitamina D con la adiposidad y marcadores del metabolismo de la diabetes lleva a deducir que la suplementación con vitamina D podría contribuir a la prevención de la obesidad y la diabetes. El diseño descriptivo transversal de nuestro estudio no ha permitido establecer algunas relaciones causales, ya que no es posible conocer si fue primero la existencia del factor de riesgo o lo fue la enfermedad, pero sí hemos podido cumplir los objetivos principales planteados

Melatonin reduced volume of cerebral infarct induced by photothrombosis in wild-type mice, not in Cyclooxygenase-1 gene knockout mice

Cyclooxygenase (COX) is crucial in inflammation and plays important role in cerebral ischemia. Anti-inflammatory effects of melatonin have been verified in previous studies. In this study, cerebral blood flow (CBF) was monitored during operation, infarct volume (IFV) was determined with 5-triphenyltetrazolium chloride (TTC) staining and MR image, and neurological functions were evaluated with turn in an alley and fall pole test in both COX-1-gene knockout and wide-type mice with or without melatonin administration 3 days after photothrombosis. CBF reduction, IFV and neurological deficits were not significantly different in COX-1 wild-type and COX-1 knockout mice. Melatonin (15 mg/kg) intraperitoneal injection decreased the CBF reduction, IFV and the latency to turn in an alley in COX-1 wide-type mice, whereas the neuroprotective effect of melatonin was attenuated in COX-1 knockout mice. We concluded that melatonin reduced susceptibility to photothrombotic stroke. COX-1 gene knockout does not alter the susceptibility to cerebral ischemia caused by photothrombosis. COX-1 plays an important role in the pathway of the protection of melatonin.published_or_final_versio

Effects of exogenous spermidine on photosynthesis, xanthophyll cycle and endogenous polyamines in cucumber seedlings exposed to salinity

The effects of exogenous spermidine (Spd, 1 mmol·L-1) on photosynthetic characteristics, xanthophylls cycle components and endogenous polyamines levels were investigated in cucumber seedlings subjected to salt stress (75 mmol·L-1 NaCl). Chlorophyll contents and net photosynthetic rate (PN) of cucumber seedlings showed a significant decrease under salinity but an increase with exogenous Spd application. Salt stress caused a remarkable decline in the maximum quantum efficiency (Fv/Fm) and the actual efficiency of photosystem II (ФPSⅡ), where an increase was observed in the constitutive loss processes (ΦNO). Application of exogenous Spd significantly decreased ФNO and enhanced regulated non-photochemical energy loss (ФNPQ) in the salt-stressed plants. Spd treatment caused an increase in the size of xanthophyll cycle pool (VAZ) and further enhanced de-epoxidation of the xanthophyll cycle (DEPS) under salt stress. These results suggest that exogenous Spd alleviated salt-mediated decline in photosynthetic efficiency through the enhanced involvement of the energy dissipation that is dependent on the xanthophyll cycle. In addition, foliar spray Spd significantly increased the free, bound and conjugated polyamines in the leaves of the salt stressed plants. Spd also increased the free putrescine (Put)/(Spd+Spm) ratio and decreased bound and conjugated Put/(Spd+Spm) under salinity. Thus, we conclude that Spd can alleviate salt-induced damage on cucumber seedlings by regulating the levels of endogenous polyamines, which was associated with an improvement in the photochemical efficiency of PSII of the salt stressed plants.Key words: Cucumber, endogenous polyamines, photosynthetic characteristics, salt stress, spermidine

Melt Emulsions: Influence of the Cooling Procedure on Crystallization and Recrystallization of Emulsion Droplets and their Influence on Dispersion Viscosity upon Storage

Emulsions with crystalline dispersed phase are widely used formulations in life sciences. Unfortunately, these products often are unstable resulting in changes of their rheological behavior. These changes could be linked to shape transformations of crystallized droplets, depending on the cooling rate in their production and temperature of storage. In a thermo-optical method, shape changes were investigated in a broad range of constant cooling rates or cooling rate ramps close to industrial processes. Cooling at slow to moderate cooling rates (0.1–50 K min$^{-1}$), as found in typical stirred vessel tanks, induced self-shaping of droplets during crystallization, which resulted in platelet-like particles and fibers, deviating greatly from the formerly spherical shape. In contrast, fast cooling as found in heat exchangers resulted in mostly spherical shapes less prone to recrystallization-induced instabilities

Nearest Neighbor Sampling of Point Sets using Random Rays

We propose a new framework for the sampling, compression, and analysis of distributions of point sets and other geometric objects embedded in Euclidean spaces. A set of randomly selected rays are projected onto their closest points in the data set, forming the ray signature. From the signature, statistical information about the data set, as well as certain geometrical information, can be extracted, independent of the ray set. We present promising results from "RayNN", a neural network for the classification of point clouds based on ray signatures