94 research outputs found

    Plant chemicals and the sexual behavior of male tephritid fruit flies

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    Plant compounds affect insects in many different ways. In addition to being a food source, plants also contain secondary metabolites that may have positive and negative impacts on insects. The influence of these compounds on sexual behavior, in particular, has been the focus of many recent studies. Here, we review the existing literature on the effects of plant compounds on the sexual behavior of tephritid fruit fly males. We put special focus on polyphagous species whose males congregate in leks, where females exert strong mate selection. We first summarize the main findings related to plant compounds that increase male signaling behavior and attraction of females and consequently increase mating frequency, a phenomenon that has been recorded mainly for species of Anastrepha and Ceratitis. In other tephritid species, males are attracted to phenylpropanoids produced by plants (such as methyl eugenol or raspberry ketone) that, upon encounter, are consumed and sequestered by males. These compounds, or metabolic derivatives, which normally have negligible nutritional value, are included in the pheromone and also confer advantages in a sexual context: enhanced female attraction and improved male mating success. These phenomena have been reported for several Bactrocera species as well as for Zeugodacus cucurbitae. Because many tephritid species are serious pests, the effect of plant compounds on male behavior has been explored for potential incorporation into control strategies such as the sterile insect technique (SIT). We conclude noting several factors, such as age and nutrition during larval and adult stage, that modulate the effect of plant compounds on male mating behavior as well as some prominent gaps that preclude a thorough understanding of the plant-mediated enhancement of male sexual performance and hence limit our ability to effectively utilize phytochemicals in pest control strategies.Instituto de GenéticaFil: Segura, Diego Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Belliard, Silvina A. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vera, María Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Bachmann, Guillermo Enrique. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ruiz, María Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Jofre-Barud, Flavia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fernández, Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Delta del Paraná; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lopez, M. Liza. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Shelly, Todd E. United States Department of Agriculture. Animal and Plant Health Inspection Service; Estados Unido

    an introduction to personalized ehealth

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    Personalized medicine can be defined as the adaptation of medical treatments to the specific characteristics of patients. This approach allows health providers to develop therapies and interventions by taking into account the heterogeneity of illnesses and external factors such as the environment, patients' needs, and lifestyle. Technology could play an important role to achieve this new approach to medicine. An example of technology's utility regards real-time monitoring of individual well-being (subjective and objective), in order to improve disease management through data-driven personalized treatment recommendations. Another important example is an interface designed based on patient's capabilities and preferences. These could improve patient-doctor communication: on one hand, patients have the possibility to improve health decision-making; on the other hand, health providers could coordinate care services more easily, because of continual access to patient's data. This contribution deepens these technologies and related opportunities for health, as well as recommendation for successful development and implementation

    Creativity in engineering mathematical models through programming

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    We discuss classroom activity comprised of small groups of students collaboratively tinkering with programs of dynamically manipulable figural models, posing problems regarding their mathematical properties and behaviors. We analyzed data from students’ discourse taken from two classroom interventions employing a framework of creative mathematical action-in-context, in order to study student-generated ideas. We approached students' actions taking a fallible mathematics epistemological approach and employed constructionist and social creativity theory in our analysis. Our results show that student agency in the disciplined field of mathematical thinking need not curtail the potential for undisciplined creative action: on the contrary, given appropriate tools and discursive environments it may in fact create space for actions with creative potential for students. On their own accord, the students in the study used generalized number theory to resolve engineering a parallelogram that can never be a rectangle, and used recursion to program a model embedding geometrical progression in order to create a spiral based on the golden ratio. © 2021, FIZ Karlsruhe

    A dynamic programming algorithm for the buffer allocation problem in homogeneous asymptotically reliable serial production lines

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    <p>In this study, the buffer allocation problem (BAP) in homogeneous, asymptotically reliable serial production lines is considered. A known aggregation method, given by Lim, Meerkov, and Top (1990), for the performance evaluation (i.e., estimation of throughput) of this type of production lines when the buffer allocation is known, is used as an evaluative method in conjunction with a newly developed dynamic programming (DP) algorithm for the BAP. The proposed algorithm is applied to production lines where the number of machines is varying from four up to a hundred machines. The proposed algorithm is fast because it reduces the volume of computations by rejecting allocations that do not lead to maximization of the line's throughput. Numerical results are also given for large production lines.</p

    Exact analysis of a two-workstation one-buffer flow line with parallel unreliable machines

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    This paper examines a model of a serial flow line with two workstations and an intermediate buffer. Each workstation consists of multiple unreliable parallel machines which are not necessarily identical, viz., the processing times, failure times and repair times of the parallel machines at each workstation are assumed to be exponentially distributed with non-identical mean rates. The system under consideration is solved via exact Markovian analysis. More specifically, a recursive algorithm that generates the transition matrix for any value of the intermediate buffer capacity is developed and all possible transition equations are derived and solved analytically. Once the transition equations are solved the performance measures of the model under consideration can be easily evaluated. This model may be used as a decomposition block for solving larger flow lines with parallel unreliable machines at each workstation.Flow/production lines Unreliable parallel-machine workstations Performance evaluation Markovian analysis

    Minding the gap and overlap: a literature review of fragmentation of primary care for chronic dialysis patients

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    Abstract Background Care coordination is a challenge for patients with kidney disease, who often see multiple providers to manage their associated complex chronic conditions. Much of the focus has been on primary care physician (PCP) and nephrologist collaboration in the early stages of chronic kidney disease, but less is known about the co-management of the patients in the end-stage of renal disease. We conducted a systematic review and synthesis of empirical studies on primary care services for dialysis patients. Methods Systematic literature search of MEDLINE/PubMED, CINAHL, and EmBase databases for studies, published until August 2015. Inclusion criteria included publications in English, empirical studies involving human subjects (e.g., patients, physicians), conducted in US and Canadian study settings that evaluated primary care services in the dialysis patient population. Results Fourteen articles examined three major themes of primary care services for dialysis patients: perceived roles of providers, estimated time in providing primary care, and the extent of dialysis patients’ use of primary care services. There was general agreement among providers that PCPs should be involved but time, appropriate roles, and miscommunication are potential barriers to good primary care for dialysis patients. Although many dialysis patients report having a PCP, the majority rely on primary care from their nephrologists. Studies using administrative data found lower rates of preventive care services than found in studies relying on provider or patient self-report. Discussion The extant literature revealed gaps and opportunities to optimize primary care services for dialysis patients, foreshadowing the challenges and promise of Accountable Care / End-Stage Seamless Care Organizations and care coordination programs currently underway in the United States to improve clinical and logistical complexities of care for this commonly overlooked population. Studies linking the relationship between providers and patients’ receipt of primary care to outcomes will serve as important comparisons to the nascent care models for ESRD patients, whose value is yet to be determined

    Extreme actions and climate change: Experience gained in South Africa and Germany

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    Please help populate SUNScholar with the full text of SU research output. Also - should you need this item urgently, please send us the details and we will try to get hold of the full text as quick possible. E-mail to [email protected]. Thank you.IngenieursweseSiviele Ingenieurswes
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