18,841 research outputs found

    Shape evolution and shape coexistence in Pt isotopes: comparing interacting boson model configuration mixing and Gogny mean-field energy surfaces

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    The evolution of the total energy surface and the nuclear shape in the isotopic chain 172−194^{172-194}Pt are studied in the framework of the interacting boson model, including configuration mixing. The results are compared with a self-consistent Hartree-Fock-Bogoliubov calculation using the Gogny-D1S interaction and a good agreement between both approaches shows up. The evolution of the deformation parameters points towards the presence of two different coexisting configurations in the region 176 ≤\leq A ≤\leq 186.Comment: Submitted to PR

    Legal Status Effects on Parent-Child Relationships and Parent Well-Being

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    Despite heightened levels of parenting stress and psychological distress experienced by many immigrant-origin families in the United States, little is known about the resiliency of Latinx families, particularly in today’s political climate. This research presents the results of a pilot study examining the effects of legal stressors on parent-child relationships and parent well-being in Latinx immigrant families. Taken from the Latinx Immigrant Family Stories and Strengths project, this mixed-methods study was informed by the integrative risk and resilience model for understanding the adaptation of immigrant-origin children and youth (Suarez-Orozco, Motti- Stefanidi, Marks, & Katsiaficas, 2018). The pilot included a sample of 30 adult parent participants with various legal statuses and migration experiences. Qualitatively, participants shared their experiences of legal vulnerability, fears or concerns of deportation, and coping mechanisms. Quantitatively, scores for parental stress, psychological distress, post-traumatic stress disorder (PTSD) symptoms, and resilience were collected. Following a, sequential explanatory design (Creswell et al., 2003), quantitative data were analyzed for relationships among study variables. A case-oriented research comparative strategy (Eckstein, 1975; Mahoney & Goertz, 2004; George & Bennett, 2005; Gerring, 2006) was then used to qualitatively examine the migration and resiliency experiences of the two cases with lowest and highest levels of resilience according to the Brief Resilience Scale (BRS; Smith et al., 2008) scores. Results suggest that, on average, parents experienced normal to high rates of parenting-related stress, low levels of psychological distress, moderate to severe symptoms of PTSD, and low to average levels of resiliency. Parents identifying as undocumented experienced higher rates of parental stress (r = 0.49, p\u3c.05) and psychological distress (r = 0.41, p\u3c.05) compared to their liminally legal and documented peers. Although the trauma experienced by many immigrant-origin parents in the study was markedly high, resilience was fostered and expressed, and was exemplified through our high-resilience case analysis. Participants’ stories expressed throughout this study spoke volumes about the complex and often times traumatic lived experiences that many foreign- born parents face. Implications for comprehensive, detailed, and longitudinal future research is discussed.https://scholarscompass.vcu.edu/gradposters/1106/thumbnail.jp

    Power-efficient space shift keying transmission via semidefinite programming

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    Space shift keying (SSK) transmission is a low-complexity complement to spatial modulation (SM) that solely relies on a spatial-constellation diagram for conveying information. The achievable performance of SSK is determined by the channel conditions, which in turn define the minimum Euclidean distance (MED) of the symbols in the received SSK constellation. In this contribution we concentrate on improving the power efficiency of SSK transmission via symbol pre-scaling. Specifically, we pose a pair of related optimization problems for a) enhancing the MED at reception while satisfying a given power constraint at the transmitter, and b) reducing the transmission power required for achieving a given MED. The resultant optimization problems are NP-hard, hence they are subsequently reformulated and solved via semidefinite programming. The results presented demonstrate that the proposed pre-scaling strategies are capable of enhancing the attainable performance of conventional SSK, while simultaneously extending its applicability and reducing the complexity of the existing pre-scaling schemes

    Effect of Time Spent on Pasture on Grazing Behaviour in Latxa Dairy Sheep

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    In the Basque country the dairy ewe production system is based on a high pasture utilisation by means of partial time grazing where ewes spend a limited number of hours outdoors (Oregui et al., 1997). This production system, which is also typical of other Mediterranean areas, is different from that in northern Europe where continuous grazing is the usual management. There is a lack of knowledge concerning grazing behaviour under these conditions. This research investigated the effect of time spent on pasture on grazing behaviour

    Effect of Time Spent on Pasture on Milk Production and Quality in Latxa Dairy Sheep

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    Dairy sheep production systems in the Basque country are pasture based. Forage resources are managed by shepherds who match herbage, forage and supplement availability with production requirements. This is achieved through a part-time grazing system, where ewes spend 3 to 7 hours grazing. The aim of this study was to evaluate the effect of restricted access to pasture on milk production and quality

    Construction and Calibration of a Low-Cost 3D Laser Scanner with 360â—¦ Field of View for Mobile Robots

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    Navigation of many mobile robots relies on environmental information obtained from three-dimensional (3D) laser scanners. This paper presents a new 360◦ field-of-view 3D laser scanner for mobile robots that avoids the high cost of commercial devices. The 3D scanner is based on spinning a Hokuyo UTM- 30LX-EX two-dimensional (2D) rangefinder around its optical center. The proposed design profits from lessons learned with the development of a previous 3D scanner with pitching motion. Intrinsic calibration of the new device has been performed to obtain both temporal and geometric parameters. The paper also shows the integration of the 3D device in the outdoor mobile robot Andabata.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    High temperatures effect on morpho-physiological indicators in common bean (Phaseolus vulgaris L.) plants during the germination and growth in non-optimum season

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    The knowledge about high temperature effect on plant crop is important for adaptation strategies to Climate Change. For this reason the aim of the paper was to analyze its abiotic effect on common bean cultivation in a Red Ferralitic soil. A sowing of twelve varieties was performed in non-optimum season (high heat environment) during three years: 2013, 2014 and 2015 through an alpha-Latin design using three replicates per accession. The number of germinated plants was measured within the first 11 days after sowing to obtain the survival percentage. In the same way absolute (AGR) and relative (RGR) growth rate between 21 and 30 days and the plant height from 20 to 70 days with measurement ranges of 10 and 15 days were also evaluated and plotted by a logistic model. The values of daily mean temperature (DMT) were registered to calculate the accumulative temperature during the germination and growth phases. For the statistical evaluation, AGR and RGR were analyzed by one-way analysis of variance and a Tukey comparison where significance was defined with a probability level of P<0.05. The results showed that plant survival percentage was significantly affected by increasing temperature following a sigmoid model, where differences among varieties were observed, while a prediction of survival behavior was also carried out for extreme values of temperature. The model corroborated that DMT above 28 C decreases the survival percentage until values less than 30%. On the other hand the most sensible varieties in the germination stage showed a higher relative growth rate which contributes for understanding the physiological effect of thermal stress in common bean plants
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