1,733 research outputs found

    Comparison of morphomeristical variations of Mediterranean and Red Sea populations of the Suez Canal migrant Sargocentron rubrum

    Get PDF
    Nine morphomeristical characters of squirrelfish, Sargocentron rubrum (Forsskal 1775) were compared between Mediterranean and Red Sea populations to examine changes caused by different environments. The significantly lower number of lateral line scales and vertebrae in the Mediterranean fishes is attributed to the higher temperature during the spawning season. The significant difference of the proportion of suborbital spinulation and the shape of the anterior tip of the nasal bone is inferred to be due to a founder effect. No significant difference was found in the relationship between eye diameter and preopercular spine length and standard length, nor in the number of dorsal and anal rays and nostril spinulation.peer-reviewe

    Dynamic management for business processes modeling & execution in workflows

    Get PDF
    Contemporary workflow-management systems cannot represent change or evolution of business processes. When a change is needed due to external reason, an offline procedure is invoked in order to create a new workflow engine template for the future instances in the workflow enactment module. The standard interfaces do not deal with the business process metadata in a way that can actually change it as a reaction to inbound knowledge. There are many relevant cases, especially in the virtual enterprise arena, where the business process is not deterministic and is influenced by external parameters (such as the selection of virtual partners), so the knowledge of what should be done is available, however it is external to the system. There is a need to develop a modeling mechanism that enables to transfer process definitions in an automatic way, without the need for human interference. One way of confronting with these issues is the use of a rule-based engine to monitor business process execution. This engine will contain internal meta-rules that refer to metadata entities, i.e. rules that describe how to act on other rules (business process routing) when a change is detected, while executing all needed consistency checks

    High-throughput data analysis in behavior genetics

    Full text link
    In recent years, a growing need has arisen in different fields for the development of computational systems for automated analysis of large amounts of data (high-throughput). Dealing with nonstandard noise structure and outliers, that could have been detected and corrected in manual analysis, must now be built into the system with the aid of robust methods. We discuss such problems and present insights and solutions in the context of behavior genetics, where data consists of a time series of locations of a mouse in a circular arena. In order to estimate the location, velocity and acceleration of the mouse, and identify stops, we use a nonstandard mix of robust and resistant methods: LOWESS and repeated running median. In addition, we argue that protection against small deviations from experimental protocols can be handled automatically using statistical methods. In our case, it is of biological interest to measure a rodent's distance from the arena's wall, but this measure is corrupted if the arena is not a perfect circle, as required in the protocol. The problem is addressed by estimating robustly the actual boundary of the arena and its center using a nonparametric regression quantile of the behavioral data, with the aid of a fast algorithm developed for that purpose.Comment: Published in at http://dx.doi.org/10.1214/09-AOAS304 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

    MR imaging–derived oxygen-hemoglobin dissociation curves and fetal-placental oxygen-hemoglobin affinities

    Get PDF
    PURPOSE: To generate magnetic resonance (MR) imaging–derived, oxygen-hemoglobin dissociation curves and to map fetal-placental oxygen-hemoglobin affinity in pregnant mice noninvasively by combining blood oxygen level–dependent (BOLD) T2* and oxygen-weighted T1 contrast mechanisms under different respiration challenges. MATERIALS AND METHODS: All procedures were approved by the Weizmann Institutional Animal Care and Use Committee. Pregnant mice were analyzed with MR imaging at 9.4 T on embryonic days 14.5 (eight dams and 58 fetuses; imprinting control region ICR strain) and 17.5 (21 dams and 158 fetuses) under respiration challenges ranging from hyperoxia to hypoxia (10 levels of oxygenation, 100%–10%; total imaging time, 100 minutes). A shorter protocol with normoxia to hyperoxia was also performed (five levels of oxygenation, 20%–100%; total imaging time, 60 minutes). Fast spin-echo anatomic images were obtained, followed by sequential acquisition of three-dimensional gradient-echo T2*- and T1-weighted images. Automated registration was applied to align regions of interest of the entire placenta, fetal liver, and maternal liver. Results were compared by using a two-tailed unpaired Student t test. R1 and R2* values were derived for each tissue. MR imaging–based oxygen-hemoglobin dissociation curves were constructed by nonlinear least square fitting of 1 minus the change in R2*divided by R2*at baseline as a function of R1 to a sigmoid-shaped curve. The apparent P50 (oxygen tension at which hemoglobin is 50% saturated) value was derived from the curves, calculated as the R1 scaled value (x) at which the change in R2* divided by R2*at baseline scaled (y) equals 0.5. RESULTS: The apparent P50 values were significantly lower in fetal liver than in maternal liver for both gestation stages (day 14.5: 21% ± 5 [P = .04] and day 17.5: 41% ± 7 [P < .0001]). The placenta showed a reduction of 18% ± 4 in mean apparent P50 values from day 14.5 to day 17.5 (P = .003). Reproduction of the MR imaging–based oxygen-hemoglobin dissociation curves with a shorter protocol that excluded the hypoxic periods was demonstrated. CONCLUSION: MR imaging–based oxygen-hemoglobin dissociation curves and oxygen-hemoglobin affinity information were derived for pregnant mice by using 9.4-T MR imaging, which suggests a potential to overcome the need for direct sampling of fetal or maternal blood. Online supplemental material is available for this article

    Machine learning-guided synthesis of advanced inorganic materials

    Full text link
    Synthesis of advanced inorganic materials with minimum number of trials is of paramount importance towards the acceleration of inorganic materials development. The enormous complexity involved in existing multi-variable synthesis methods leads to high uncertainty, numerous trials and exorbitant cost. Recently, machine learning (ML) has demonstrated tremendous potential for material research. Here, we report the application of ML to optimize and accelerate material synthesis process in two representative multi-variable systems. A classification ML model on chemical vapor deposition-grown MoS2 is established, capable of optimizing the synthesis conditions to achieve higher success rate. While a regression model is constructed on the hydrothermal-synthesized carbon quantum dots, to enhance the process-related properties such as the photoluminescence quantum yield. Progressive adaptive model is further developed, aiming to involve ML at the beginning stage of new material synthesis. Optimization of the experimental outcome with minimized number of trials can be achieved with the effective feedback loops. This work serves as proof of concept revealing the feasibility and remarkable capability of ML to facilitate the synthesis of inorganic materials, and opens up a new window for accelerating material development

    Fishes of the Eastern Mediterranean

    Get PDF
    Few seas have evidenced an environmental impact throughout human history to the degree that the eastern Mediterranean has. In the last century alone, the Levant Basin has seen the opening of the Suez Canal, leading to a massive Red Sea biological invasion, and construction of the Aswan Dam on the Nile River, leading to an abrupt cessation of its annual floodwaters. These man-made activi- ties have had a serious impact on the eastern Mediterranean causing the collapse of some fisheries, the creation of others, and large- scale alterations in the ecosystem. This book deals with fish species living in the Levant Basin and includes all currently-known indige- nous and immigrant species

    Generative rules of Drosophila locomotor behavior as a candidate homology across phyla

    Get PDF
    The discovery of shared behavioral processes across phyla is a significant step in the establishment of a comparative study of behavior. We use immobility as an origin and reference for the measurement of fly locomotor behavior; speed, walking direction and trunk orientation as the degrees of freedom shaping this behavior; and cocaine as the parameter inducing progressive transitions in and out of immobility. We characterize and quantify the generative rules that shape Drosophila locomotor behavior, bringing about a gradual buildup of kinematic degrees of freedom during the transition from immobility to normal behavior, and the opposite narrowing down into immobility. Transitions into immobility unfold via sequential enhancement and then elimination of translation, curvature and finally rotation. Transitions out of immobility unfold by progressive addition of these degrees of freedom in the opposite order. The same generative rules have been found in vertebrate locomotor behavior in several contexts (pharmacological manipulations, ontogeny, social interactions) involving transitions in-and-out of immobility. Recent claims for deep homology between arthropod central complex and vertebrate basal ganglia provide an opportunity to examine whether the rules we report also share common descent. Our approach prompts the discovery of behavioral homologies, contributing to the elusive problem of behavioral evolution
    corecore