Effects of blood vessel permeability on mechanical properties of bone under micro-gravity conditions

Loss of bone mass is one important physiological change observed in astronauts after medium and long-term exposure to microgravity conditions. The objective of the current study is to test the hypothesis that loss of bone mass under microgravity can be inhibited if the same micro-force distribution under earth gravity (body weight) is achieved by increasing the blood vessel permeability to increase the transcortical interstitial fluid flow. A method of exposure to bio-frequency spectrum (BFS) light (infrared to micrometer wavelength) was used to increase the blood vessel permeability. We tested the hypothesis by examining the bone mechanical properties (Young\u27s modulus) of rat femur and humerus for four groups of animals. (i) control, (ii) exposure to a bio-frequency spectrum (BFS) light, (iii) tail-suspension (simulating microgravity condition), and (iv) tail-suspension and exposure to a bio-frequency spectrum (BFS) light. Twenty-eight adult rats of ∼250 g were used and kept for 50 days before sacrificing. The average Young\u27s moduli for each group of rat femurs are (i) 1.78 GPa, (ii) 2.04 GPa, (iii) 2.03 GPa

Zero-Inflated Models to Identify Transcription Factor Binding Sites in ChIP-seq Experiments

It is essential to determine the protein-DNA binding sites to understand many biological processes. A transcription factor is a particular type of protein that binds to DNA and controls gene regulation in living organisms. Chromatin immunoprecipitation followed by highthroughput sequencing (ChIP-seq) is considered the gold standard in locating these binding sites and programs use to identify DNA-transcription factor binding sites are known as peak-callers. ChIP-seq data are known to exhibit considerable background noise and other biases. In this study, we propose a negative binomial model (NB), a zero-inflated Poisson model (ZIP) and a zero-inflated negative binomial model (ZINB) for peak-calling. Using real ChIP-seq datasets, we show that ZINB model is the best model for ChIP-seq data. Then we incorporate control data, GC count information, and mappability information into the ZINB regression model as covariates using two link functions. We implemented this approach in C++, and our peak-caller chooses the optimal parameter combination for a given dataset. Performace of our approach is compared with two frequently used peak-callers: QuEST and MACS

Titania Nanotubes/Hydroxyapatite Nanocomposites Produced with the Use of the Atomic Layer Deposition Technique: Estimation of Bioactivity and Nanomechanical Properties

Titanium dioxide nanotubes/hydroxyapatite nanocomposites were produced on a titanium alloy (Ti6Al4V/TNT/HA) and studied as a biocompatible coating for an implant surface modification. As a novel approach for this type of nanocomposite fabrication, the atomic layer deposition (ALD) method with an extremely low number of cycles was used to enrich titania nanotubes (TNT) with a very thin hydroxyapatite coating. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used for determination of the structure and the surface morphology of the fabricated nanocoatings. The biointegration activity of the layers was estimated based on fibroblasts’ proliferation on the TNT/HA surface. The antibacterial activity was determined by analyzing the ability of the layers to inhibit bacterial colonization and biofilm formation. Mechanical properties of the Ti6Al4V/TNT/HA samples were estimated by measuring the hardness, Young’s module, and susceptibility to scratching. The results revealed that the nanoporous titanium alloy coatings enriched with a very thin hydroxyapatite layer may be a promising way to achieve the desired balance between biofunctional and biomechanical properties of modern implants

Forecast verification of the Current Icing Potential (CIP) product to predict observed lightning in the vicinity of U.S. Spaceports

Government spaceports employ extensive lightning detection networks that may not be available at commercial spaceports. As the number of commercial space operations increases, the Federal Aviation Administration identified the need for a method to diagnose the threat of triggered lightning at commercial spaceports without in-situ measurements. Charge separation that produces lightning is generated by the existence of water in solid and liquid states interacting. This mixed phase environment is also conducive to structural aircraft icing. Anecdotal observations of the Aviation Weather Center’s Current Icing Potential (CIP) numerical weather prediction model indicated a potentially high correlation between lightning activity and forecast icing potential. Analysis of three years of USPLN lightning data at spaceports across the United States provided a measure of the lightning frequency at these locations. Relatively high statistical correlations between the CIP and lightning activity in both space and time were discovered, but so were negative correlations. Since it is not possible to define a correlation when one field is constant, such as CIP values greater than zero but with no observed lightning events, a forecast verification was conducted using a traditional contingency table of forecasted (CIP) versus observed lightning events. Forecast verification studies using CIP to predict lightning, and previous lightning to predict future lightning (a persistence forecast), were performed. Case studies were also conducted to determine the CIP’s ability to diagnose lightning hazards, particularly lightning initiation, in a hypothetical operational setting. The forecast verification study, covering two years of lightning activity, determined the CIP’s ability to diagnose lightning hazards was quite limited due to extensive overprediction. Critical Success Index (CSI) scores for CIP as a lightning predictor were less than 15% in all cases. In comparison, lightning persistence forecasts achieved CSI scores closer to 40%. During the case study analyses the CIP demonstrated a number of weaknesses. The CIP: 1) failed to capture lightning initiation, 2) overpredicted the extent of lightning, 3) missed whole regions of lightning, and 4) failed to capture lightning cessation. Queries of an aviation hazard database developed by ERAU and NASA showed CIP over predicted convection in general, not just lightning. It is difficult to draw any conclusions on the CIP’s ability to diagnose lightning triggered by a launch vehicle due to insufficient documented cases of this hazard

Fungicide Sensitivity in \u3cem\u3eP. Tritici-Repentis\u3c/em\u3e Diverse Population and Phenotyping of Spelt Wheat for Multiple Diseases

Pyraclostrobin, a QoI fungicide, is extensively used in the management of fungal leaf spot diseases. In this study, 215 P. tritici-repentis isolates collected from wheat fields in South Dakota were evaluated for their sensitivity to Pyraclostrobin. Of 215 isolates, 48 isolates (22%) exhibited insensitivity based on G143A mutation and EC50 values using spore germination assay. Our results indicate reduced sensitivity to insensitivity to pyraclostrobin in some isolates suggesting regular monitoring of the P. tritici-repentis population to QoI fungicides is essential to track the evolution of insensitive population. Spelt wheat (Triticum spelta L.) is an ancient cereal that is gaining small grain growers’ attention under an organic setup due to its high protein content, high fiber, and other health benefits. In this study, two hundred-eight spelt accessions from twenty countries were screened against leaf spot diseases and leaf rust at the seedling stage in the greenhouse. The genotypes exhibited varying responses ranging from susceptible to moderately susceptible, moderately resistant, and resistant. Spelt accessions resistant to leaf rust and leaf spots will be further evaluated for the agronomic traits in the field, and results will be shared with the growers to assist in selection of superior spelt genotypes. ToxA, a necrotrophic effector has been identified from the fungus Pyrenophora tritici-repentis that causes tan spot and was later identified from Parastagonospora nodorum and P. avenaria tritici. Recently, the ToxA gene has been identified in the fungus Bipolaris sorokiniana causing spot blotch in Australia and the winter wheat region of southcentral Texas. In this study, we have tested if B. sorokiniana population of South Dakota is having ToxA gene (BS ToxA) like P. tritici-repentis and P. nodorum. 53.5% (n=68) of 127 isolates amplified the ToxA gene. Further, the culture filtrates of isolates with the ToxA gene produced necrosis symptoms in ToxA sensitive wheat cultivars. Our results indicate that there is a diverse population of B. sorokiniana prevalent on wheat in South Dakota. To our knowledge, this is the first report of ToxA (BS ToxA) producing B. sorokiniana isolates in South Dakota

Revisión sistemática realista sobre las opciones de incentivos en Colombia para la gestión en salud

Los sistemas y los mercados de los servicios de salud tienen como prioridad en sus agendas de política el tema de la mejora del desempeño y la calidad de los servicios de salud a través de la incorporación de incentivos a los agentes de interés. Este trabajo responde a la pregunta de investigación sobre cómo transferir incentivos a diferentes agentes del sistema de salud en Colombia, con especial énfasis en los proveedores de servicios de salud, para mejorar su eficiencia, en términos de la calidad de los servicios de salud, minimizando las externalidades negativas. Para responder a esta inquietud se realiza una revisión sistemática realista con la extracción de información de 42 estudios. Se utiliza un modelo lógico iterativo y basado en procesos. Como resultado se identifican seis grandes mecanismos de intervención con distintos niveles de intensidad que tratan sobre la transferencia de incentivos, específicamente a proveedores de servicios de salud, teniendo en cuenta las externalidades y sus efectos en calidad y eficiencia