Synthesis of Hafnium-Free Nanostructured Half-Heusler Materials for Thermoelectric Applications

Half-Heusler thermoelectric materials convert heat directly into electricity by means of the Seebeck effect. Improving the conversion efficiency and reducing fabrication costs will reduce the price per watt enabling widespread commercialization for waste heat energy harvesting and self-powered devices. In this work, a rapid low-cost synthesis route utilizing mechanical alloying via high energy planetary ball milling and spark plasma sintering was used to fabricate n-type hafnium-free single phase nano-grained TiZrNiSnSb based half-heusler monoliths with a modest figure of merit performance with significantly reduced thermal conductivity

The olfactive responses of Tetranychus urticae natural enemies in citrus depend on plant genotype, prey presence, and their diet specialization

[EN] Sour orange, Citrus aurantium, displays higher constitutive and earlier inducible direct defenses against the two-spotted spider mite, Tetranychus urticae, than Cleopatra mandarin, Citrus reshni. Moreover, herbivore-induced plant volatiles (HIPVs) produced by sour orange upon infestation can induce resistance in Cleopatra mandarin but not vice versa. Because the role of these HIPVs in indirect resistance remains ignored, we have carried out a series of behavioral assays with three predatory mites with different levels of specialization on this herbivore, from strict entomophagy to omnivory. We have further characterized the volatile blend associated with T. urticae, which interestingly includes the HIPV methyl salicylate, as well as that produced by induced Cleopatra mandarin plants. Although a preference for less defended plants with presumably higher prey densities (i.e., C. reshni) was expected, this was not always the case. Because predators' responses changed with diet width, with omnivore predators responding to both HIPVs and prey-related odors and specialized ones mostly to prey, our results reveal that these responses depend on plant genotype, prey presence and predator diet specialization. As the different volatile blends produced by infested sour orange, induced Cleopatra mandarin and T. urticae itself are attractive to T. urticae natural enemies but not to the herbivore, they may provide clues to develop new more sustainable tools to manipulate these agriculturally relevant species.The research leading to these results was partially funded by the Spanish Ministry of Economy and Competitiveness (AGL2014-55616-C3; AGL2015-64990-2R). The authors thank M. Piquer (UJI) for technical assistance. MC received a pre-doctoral fellowship from the Spanish Ministry of Economy and Competitiveness (BES-2015-074570), and MP was the recipient of a research fellowship from INIA, Spain (subprogram DOC INIA-CCAA).Cabedo López, M.; Cruz-Miralles, J.; Vacas, S.; Navarro-Llopis, V.; Pérez-Hedo, M.; Flors, V.; Jaques, JA. (2019). The olfactive responses of Tetranychus urticae natural enemies in citrus depend on plant genotype, prey presence, and their diet specialization. Journal of Pest Science. 92(3):1165-1177. https://doi.org/10.1007/s10340-019-01107-7S1165117792

Gestión de la cubierta vegetal para fomentar el control biológico por conservación de la mosca de la fruta Ceratitis capitata (Wiedemann) (Diptera: Tephritidae)

La gestión del suelo puede afectar tanto cualitativa como cuantitativamente a los agentes de control biológico que alberga. Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), que pasa parte de su ciclo en el suelo, es susceptible a estos organismos y, por ello, a la gestión que se realice del suelo. En este trabajo se comparó el efecto de tres tipos distintos de gestión del suelo (desnudo, acolchado con paja y cubierta vegetal de Festuca arundinacea) en condiciones de semicampo sobre la supervivencia de larvas de último estadío de C. capitata hasta su emergencia como adultos. Para determinar la mortalidad de las larvas, se expusieron con frecuencia mensual grupos de 100 larvas centinela desarrollándose en condiciones de campo en trampas de emergencia

Enhancing the early student experience

This paper is concerned with identifying how the early student experience can be enhanced in order to improve levels of student retention and achievement. The early student experience is the focus of this project as the literature has consistently declared the first year to be the most critical in shaping persistence decisions. Programme managers of courses with high and low retention rates have been interviewed to identify activities that appear to be associated with good retention rates. The results show that there are similarities in the way programmes with high retention are run, with these features not being prevalent on programmes with low retention. Recommendations of activities that appear likely to enhance the early student experience are provided

Condition of career readiness in the United States

The 2022 inaugural Condition of Career Readiness in the United States report highlights findings and recommendations to help business and industry, federal and state agencies, elected officials, and national organizations reflect on what investments and resources are needed to support the future economic competitiveness of our nation. This inaugural report describes our states’ progress towards becoming a Career Ready Nation. The report was produced for the Coalition for Career Development Center (CCD Center) by the Boston University Center for Future Readiness with support from American Student Assistance (ASA) and the Collaborative on Academic, Social and Emotional Learning (CASEL).Coalition for Career Development Centerhttps://irp.cdn-website.com/81ac0dbc/files/uploaded/CCDC-Report-nopics-V2.pdfPublished versio

Effect of stride length on the running biomechanics of healthy women of different statures

Abstract Background Tibial stress fracture is a debilitating musculoskeletal injury that diminishes the physical performance of individuals who engage in high-volume running, including Service members during basic combat training (BCT) and recreational athletes. While several studies have shown that reducing stride length decreases musculoskeletal loads and the potential risk of tibial injury, we do not know whether stride-length reduction affects individuals of varying stature differently. Methods We investigated the effects of reducing the running stride length on the biomechanics of the lower extremity of young, healthy women of different statures. Using individualized musculoskeletal and finite-element models of women of short (N = 6), medium (N = 7), and tall (N = 7) statures, we computed the joint kinematics and kinetics at the lower extremity and tibial strain for each participant as they ran on a treadmill at 3.0 m/s with their preferred stride length and with a stride length reduced by 10%. Using a probabilistic model, we estimated the stress-fracture risk for running regimens representative of U.S. Army Soldiers during BCT and recreational athletes training for a marathon. Results When study participants reduced their stride length by 10%, the joint kinetics, kinematics, tibial strain, and stress-fracture risk were not significantly different among the three stature groups. Compared to the preferred stride length, a 10% reduction in stride length significantly decreased peak hip (p = 0.002) and knee (p < 0.001) flexion angles during the stance phase. In addition, it significantly decreased the peak hip adduction (p = 0.013), hip internal rotation (p = 0.004), knee extension (p = 0.012), and ankle plantar flexion (p = 0.026) moments, as well as the hip, knee, and ankle joint reaction forces (p < 0.001) and tibial strain (p < 0.001). Finally, for the simulated regimens, reducing the stride length decreased the relative risk of stress fracture by as much as 96%. Conclusions Our results show that reducing stride length by 10% decreases musculoskeletal loads, tibial strain, and stress-fracture risk, regardless of stature. We also observed large between-subject variability, which supports the development of individualized training strategies to decrease the incidence of stress fracture

Evaluation of a multifaceted "Resident-as-Teacher" educational intervention to improve morning report

BACKGROUND: Resident-led morning report is an integral part of most residency programs and is ranked among the most valuable of educational experiences. The objectives of this study were to evaluate the effect of a resident-as-teacher educational intervention on the educational and teaching experience of morning report. METHODS: All senior internal medicine residents were invited to participate in this study as teaching participants. All internal medicine residents and clerks were invited to participate as audience participants. The educational intervention included reading material, a small group session and feedback after teaching sessions. The educational and teaching experiences were rated prior to and three months after the intervention using questionnaires. RESULTS: Forty-six audience participants and 18 teaching participants completed the questionnaires. The degree to which morning report met the educational needs of the audience was higher after the educational intervention (effect size, d = 0.26, p = 0.01). The perceptions of the audience were that delivery had improved and that the sessions were less intimidating and more interactive. The perception of the teaching participants was that delivery was less stressful, but this group now reported greater difficulty in engaging the audience and less confidence in their medical knowledge. CONCLUSION: Following the educational intervention the audience's perception was that the educational experience had improved although there were mixed results for the teaching experience. When evaluating such interventions it is important to evaluate the impact on both the educational and teaching experiences as results may differ

Search for Squarks and Gluinos in Events Containing Jets and a Large Imbalance in Transverse Energy

Using data corresponding to an integrated luminosity of 79 pb-1, D0 has searched for events containing multiple jets and large missing transverse energy in pbar-p collisions at sqrt(s)=1.8 TeV at the Fermilab Tevatron collider. Observing no significant excess beyond what is expected from the standard model, we set limits on the masses of squarks and gluinos and on the model parameters m_0 and m_1/2, in the framework of the minimal low-energy supergravity models of supersymmetry. For tan(beta) = 2 and A_0 = 0, with mu < 0, we exclude all models with m_squark < 250 GeV/c^2. For models with equal squark and gluino masses, we exclude m < 260 GeV/c^2.Comment: 10 pages, 3 figures, Submitted to PRL, Fixed typo on page bottom of p. 6 (QCD multijet background is 35.4 events

Search for Charged Higgs Bosons in Decays of Top Quark Pairs

We present a search for charged Higgs bosons in decays of pair-produced top quarks using 109.2 +- 5.8 pb^-1 of data recorded from ppbar collisions at sqrt{s} = 1.8 TeV by the D0 detector during 1992-96 at the Fermilab Tevatron. No evidence is found for charged Higgs production, and most parts of the [m(H+),tan(beta)] parameter space where the decay t -> bH+ has a branching fraction close to or larger than that for t -> bW+ are excluded at 95% confidence level. Assuming m(t) = 175 GeV and sigma(ppbar -> ttbar) = 5.5 pb, for m(H+) = 60 GeV, we exclude tan(beta) 40.9.Comment: 11 pages, 3 figures, submitted to PR