898 research outputs found
Mating Patterns and Post-Mating Isolation in Three Cryptic Species of the Engystomops Petersi Species Complex
Determining the extent of reproductive isolation in cryptic species with dynamic geographic ranges can yield important insights into the processes that generate and maintain genetic divergence in the absence of severe geographic barriers. We studied mating patterns, propensity to hybridize in nature and subsequent fertilization rates, as well as survival and development of hybrid F1 offspring for three nominal species of the Engystomops petersi species complex in Yasuní National Park, Ecuador. We found at least two species in four out of six locations sampled, and 14.3% of the wild pairs genotyped were mixed-species (heterospecific) crosses. We also found reduced fertilization rates in hybrid crosses between E. petersi females and E. “magnus” males, and between E. “magnus” females and E. “selva” males but not in the reciprocal crosses, suggesting asymmetric reproductive isolation for these species. Larval development times decreased in F1 hybrid crosses compared to same species (conspecific) crosses, but we did not find significant reduction in larval survival or early metamorph survival. Our results show evidence of post-mating isolation for at least two hybrid crosses of the cryptic species we studied. The general decrease in fertilization rates in heterospecific crosses suggests that sexual selection and reinforcement might have not only contributed to the pattern of call variation and behavioral isolation we see between species today, but they may also contribute to further signal divergence and behavioral evolution, especially in locations where hybridization is common and fertilization success is diminished
Mating Patterns and Post-Mating Isolation in Three Cryptic Species of the Engystomops Petersi Species Complex
Determining the extent of reproductive isolation in cryptic species with dynamic geographic ranges can yield important insights into the processes that generate and maintain genetic divergence in the absence of severe geographic barriers. We studied mating patterns, propensity to hybridize in nature and subsequent fertilization rates, as well as survival and development of hybrid F1 offspring for three nominal species of the Engystomops petersi species complex in Yasuní National Park, Ecuador. We found at least two species in four out of six locations sampled, and 14.3% of the wild pairs genotyped were mixed-species (heterospecific) crosses. We also found reduced fertilization rates in hybrid crosses between E. petersi females and E. “magnus” males, and between E. “magnus” females and E. “selva” males but not in the reciprocal crosses, suggesting asymmetric reproductive isolation for these species. Larval development times decreased in F1 hybrid crosses compared to same species (conspecific) crosses, but we did not find significant reduction in larval survival or early metamorph survival. Our results show evidence of post-mating isolation for at least two hybrid crosses of the cryptic species we studied. The general decrease in fertilization rates in heterospecific crosses suggests that sexual selection and reinforcement might have not only contributed to the pattern of call variation and behavioral isolation we see between species today, but they may also contribute to further signal divergence and behavioral evolution, especially in locations where hybridization is common and fertilization success is diminished
Advanced Communication Technology Satellite (ACTS) multibeam antenna analysis and experiment
One of the most important aspects of a satellite communication system design is the accurate estimation of antenna performance degradation. Pointing error, end coverage gain, peak gain degradation, etc. are the main concerns. The thermal or dynamic distortions of a reflector antenna structural system can affect the far-field antenna power distribution in a least four ways. (1) The antenna gain is reduced; (2) the main lobe of the antenna can be mispointed thus shifting the destination of the delivered power away from the desired locations; (3) the main lobe of the antenna pattern can be broadened, thus spreading the RF power over a larger area than desired; and (4) the antenna pattern sidelobes can increase, thus increasing the chances of interference among adjacent beams of multiple beam antenna system or with antenna beams of other satellites. The in-house developed NASA Lewis Research Center thermal/structural/RF analysis program was designed to accurately simulate the ACTS in-orbit thermal environment and predict the RF antenna performance. The program combines well establish computer programs (TRASYS, SINDA and NASTAN) with a dual reflector-physical optics RF analysis program. The ACTS multibeam antenna configuration is analyzed and several thermal cases are presented and compared with measurements (pre-flight)
Editorial: Nanobiophotonics and Related Novel Materials Aimed at Biosciences and Biomedicine
Editorial on the Research Topic
Nanobiophotonics and Related Novel Materials Aimed at Biosciences and Biomedicin
Comparative study about the use of two and three-dimensional methods in surface finishing characterization
The increasing number of works related to the surface texture characterization based on 3D information, makes convenient rethinking traditional methods based on two-dimensional measurements from profiles. This work compares results between measurements obtained using two and three-dimensional methods. It uses three kinds of data sources: reference surfaces, randomly generated surfaces and measured. Preliminary results are presented. These results must be completed trying to cover a wider number of possibilities according to the manufacturing process and the measurement instrumentation since results can vary quite significantly between them
Evaluation of Fat-free Mass Characteristics at Different Adiposity Levels: Impact of Weight Status Stratification Method
The method used to stratify weight status when evaluating fat-free mass (FFM) characteristics has primarily been based upon body mass index (BMI) and not body fat percent (BF%). As a result, it is unknown whether deviations in FFM characteristics are similar when stratifying weight status based upon BMI or BF%. Purpose: The purpose of this study was to evaluate FFM characteristics at different adiposity levels when stratifying weight status via BMI and BF%. Methods: 150 adults (50% males) participated in this study. 3-compartment (3C) model body composition was based upon body density (Db) via air displacement plethysmography (ADP) and total body water via bioimpedance analysis. FFM density (DFFM), residual (RFFM), and hydration (HFFM)were evaluated in all subjects. The Db obtained from a stand-alone assessment of ADP (2C-Db) and 3C model (3C-Db)were also compared between groups. Subjects were stratified based upon weight status (BMI and BF%). First, subjects were divided into a normal weight (NW-BMI), overweight (OW-BMI) or obese (OB-BMI) group, which were based upon BMI values of 18.5-24.99 kg/m2 (n=50), 25.0-29.99 kg/m2 (n=50), and ³ 30.0 kg/m2 (n=50), respectively. Next, subjects were divided into groups based upon BF% where normal weight BF% values (NW-BF%) for males and females were \u3c 25 and 35% (n=81), respectively, and obese BF% values (OB-BF%) were ³25 and 35% (n=69), respectively. Results: The DFFM ranged from 1.096 – 1.097 g/cm3 for all groups in both weight status stratification methods (all p \u3e 0.05). HFFM and RFFM were similar for all comparisons and ranged from 73.99 – 74.33% and 25.67 – 26.01%, respectively, for BMI groups and 74.02 – 74.26% and 25.74 – 25.98%, respectively, for BF% groups (all p \u3e 0.05). In contrast, the 3C-Db (1.050, 1.036, and 1.013 g/cm3) and 2C-Db (1.051, 1.036, and 1.014 g/cm3) were statistically significant for all comparisons between NW-BMI, OW-BMI, and OB-BMI respectively (all p \u3c 0.05). Furthermore, 3C-Db (1.051 and 1.011 g/cm3) and 2C-Db (1.052 and 1.012 g/cm3) were significantly different when comparing NW-BF% and OB-BF% (both p \u3c 0.05). CONCLUSIONS: Previous research has reported the FFM characteristics when stratifying weight status via BMI classification. As a result, it was unknown whether deviations in FFM characteristics existed when stratifying by BF%. Uniquely, the current study findings revealed that FFM characteristics are similar between groups regardless of the weight status stratification method (BMI or BF%)
An approach to predicting patient experience through machine learning and social network analysis.
OBJECTIVE:Improving the patient experience has become an essential component of any healthcare system\u27s performance metrics portfolio. In this study, we developed a machine learning model to predict a patient\u27s response to the Hospital Consumer Assessment of Healthcare Providers and Systems survey\u27s Doctor Communications domain questions while simultaneously identifying most impactful providers in a network. MATERIALS AND METHODS:This is an observational study of patients admitted to a single tertiary care hospital between 2016 and 2020. Using machine learning algorithms, electronic health record data were used to predict patient responses to Hospital Consumer Assessment of Healthcare Providers and Systems survey questions in the doctor domain, and patients who are at risk for responding negatively were identified. Model performance was assessed by area under receiver-operating characteristic curve. Social network analysis metrics were also used to identify providers most impactful to patient experience. RESULTS:Using a random forest algorithm, patients\u27 responses to the following 3 questions were predicted: During this hospital stay how often did doctors. 1) treat you with courtesy and respect? 2) explain things in a way that you could understand? 3) listen carefully to you? with areas under the receiver-operating characteristic curve of 0.876, 0.819, and 0.819, respectively. Social network analysis found that doctors with higher centrality appear to have an outsized influence on patient experience, as measured by rank in the random forest model in the doctor domain. CONCLUSIONS:A machine learning algorithm identified patients at risk of a negative experience. Furthermore, a doctor social network framework provides metrics for identifying those providers that are most influential on the patient experience
Rendimiento de dos variedades mejoradas de frijol, sembrados al voleo al espeque, en Moss Pam, Waspam, Río Coco
This article presents the agronomic behavior of the beans (Phaseolus vulgaris L.) in two varieties: (DOR-364 and M-46), that were established through the analysis of two planting methods (broadcast and handspike) to measure the production. The experiment was conducted in the academic farm of Snaky/URACCAN, located in the community of Moss Pam, municipality of Waspam, Rio Coco, North Autonomous Atlantic Region (RAAN). The bean crop is of great importance in the lives of indigenous communities, since just as the rice, it constitutes the most important grain in the family’s diets. It should be noted that the indigenous communities of the RAAN basically used two methods of planting (broadcast and handspike), however, productions is always low, so is necessary to make the study with the conditions that have been described. A bifactorial design in randomized complete blocks was used, where the factor A: is equivalent to the two varieties of beans (DOR-364 and H-46), and factor B, is equivalent to two methods of planting (broadcast and handspike). The evaluation was made on the morphometric characteristics presented in the vegetative and reproductive phase of the crop. The information processing was done with the statistical program InfoStat, making an investigation from the analysis of ANAVA and Kruskal-Wallis test. The results showed high germination viability (95%), with statistical differences between treatments in the variables: height and diameter, in the vegetative stage. In the reproductive stage the variables: number of pods/plants and seeds/pods/plants, were the one that presented statistical differences between treatments, contrary to the variables: number of flowers/plants and length of pods/plants, that showed no differences. Finally, the ANAVA with 95 percent of reliability found differences in the variable: performance. Is recommended to plant the variety H-46 using the broadcast method and that DOR-364 variety be planted by handspike, because it present the best production with 77.63 and 71.33 qq/mz.Este articulo presenta el comportamiento agronómico del frijol (Phaseolus vulgaris L.) en dos variedades:(DOR-364 y H-46), establecidos a través del análisis de dos métodos de siembra (al voleo y al espeque), para medir la variable rendimiento. El experimento se realizó en la finca académica SNAKY/URACCAN, ubicada en la comunidad Moss Pam, en el municipio de Waspam río Coco, Región Autónoma Atlántico Norte (RAAN). El cultivo de frijol es de gran relevancia en la vida de las comunidades indígenas, ya que constituye al igual que el arroz, el grano de mayor importancia en la dieta familiar. Es de mencionar que las comunidades indígenas de la RAAN utilizan básicamente dos métodos de siembra (al voleo y al espeque); no obstante, siempre los rendimientos son bajos, por lo que se hace necesario el estudio con las condiciones descritas. Se utilizó un diseño bifactorial en bloques completos al azar, en donde el factor A: equivale a las dos variedades de frijol (DOR-364 y H-46), y el factor B: dos métodos de siembra (al voleo y al espeque). La evaluación se hizo sobre las características morfométricas presentadas en la fase vegetativa y reproductiva del cultivo. El procesamiento de la información se hizo con el programa estadístico InfoStat, indagando desde el análisis del ANAVA y la prueba Kruskal-Wallis. Los resultados mostraron una alta viabilidad germinativa (95%), con diferencias estadísticas entre tratamientos en las variables altura y diámetro en la etapa vegetativa. En la etapa reproductiva las variables: número de vainas/plantas y granos/vainas/plantas, fueron las que presentaron diferencias estadísticas entre tratamientos, contrario a las variables número de flores/plantas y longitud de vainas/plantas que no mostraron diferencias. Finalmente el ANAVA con un 95 por ciento de confiabilidad encontró diferencias de medias en la variable rendimiento. Se recomienda el establecimiento de la variedad H-46 sea sembrada al voleo y la variedad DOR-364 sembrada al espeque, por presentar los mejores rendimientos con 77.63 y 71.33 qq/mz
Identification and expression pattern of a new carotenoid cleavage dioxygenase gene member from Bixa orellana
Carotenoid cleavage dioxygenases (CCDs) are a class of enzymes involved in the biosynthesis of a broad diversity of secondary metabolites known as apocarotenoids. In plants, CCDs are part of a genetic family with members which cleave specific double bonds of carotenoid molecules. CCDs are involved in the production of diverse and important metabolites such as vitamin A and abscisic acid (ABA). Bixa orellana L. is the main source of the natural pigment annatto or bixin, an apocarotenoid accumulated in large quantities in its seeds. Bixin biosynthesis has been studied and the involvement of a CCD has been confirmed in vitro. However, the CCD genes involved in the biosynthesis of the wide variety of apocarotenoids found in this plant have not been well documented. In this study, a new CCD1 gene member (BoCCD1) was identified and its expression was charaterized in different plant tissues of B. orellana plantlets and adult plants. The BoCCD1 sequence showed high homology with plant CCD1s involved mainly in the cleavage of carotenoids in several sites to generate multiple apocarotenoid products. Here, the expression profiles of the BoCCD1 gene were analysed and discussed in relation to total carotenoids and other important apocarotenoids such as bixin
Eco-Epidemiological and Immunological Features of Localized Cutaneous Leishmaniasis in Southeastern Mexico: Thirty Years of Study
The Yucatan Peninsula is considered an important endemic area of localized cutaneous leishmaniasis (LCL) caused by Leishmania (Leishmania) mexicana and mainly the states of Campeche and Quintana Roo where 41.5% of all new cases in Mexico were reported in 2015. People were affected due to the lack of the resources for early diagnosis and treatment and although many aspects of the disease are known, control of LCL is absent in this region. Thus, better case detection and epidemiological surveillance are required. The presence of emerging focus and changes in the clinical form suggest the importance of continuing the eco-epidemiological studies, which could lead to the implementation of a sustainable control on the disease. In this review, we focus on the results of our multi-disciplinary studies carried out in the southeastern Mexico, including LCL burden, clinical aspects, causal agents, vectors, reservoirs and the host immune response to Leishmania (L.) mexicana infection
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