Asunto(s)

RESUMEN

We studied the direct (lethal) and indirect (sublethal) effects of field-aged insecticide residues of spinetoram, chlorantraniliprole and lambda-cyhalothrin on adults and larvae of the green lacewing, Chrysoperla johnsoni Henry, Wells and Pupedis an important generalist predator in western United States pear orchards. We applied formulated pesticides using their high label rates mixed with 935 liters/ha of water on pear trees utilizing an airblast sprayer. We collected leaves from the experiment trees at 1, 7, 14, 21 days after treatment (DAT) and exposed C. johnsoni adults and second instars to insecticide residues or untreated control for 72 h. We monitored larvae that survived the treatments until adult emergence (for larvae) or adults until death (for paired adults). We assessed the adults for acute and chronic mortality, longevity, fecundity, and fertility, and larvae for acute mortality, sex ratio, developmental time, and survival of adults emerged from treated second instars, to determine lethal and sublethal effects. The field-exposed insecticide residues of chlorantraniliprole exhibited higher lethal and sublethal toxicities on C. johnsoni during the 21-d leaf collection period when compared with the field-exposed residue toxicities of lambda-cyhalothrin and spinetoram. The field-exposed residue of lambda-cyhalothrin and spinetoram exhibited moderate toxicities on C. johnsoni during the 21-d leaf collection period. Results from this study show similar trends with previous studies using multiple routes of exposure laboratory assays and field experiments on Chrysoperla sp. The direct and indirect effects of field-aged residues of spinetoram, chlorantraniliprole, and lambda-cyhalothrin on C. johnsoni are discussed.

Asunto(s)

RESUMEN

This mixed-methods study examined variables associated with use of experience-based (i.e., anecdotal) decisional strategies among 85 undergraduate students presented with 2 hypothetical lung cancer scenarios. Participants were asked to think aloud while they made their treatment choice. Eleven decisional strategies were identified and grouped into either data or experience-based strategies. Approximately, 25% of participants used experience-based strategies. Use of experience-based strategies was more likely if the participant reported involvement in the life of someone going through cancer treatment, and if they rated print-based media sources as less important. Use of experience-based strategies was associated with choosing surgery instead of radiation for lung cancer treatment.

Asunto(s)

RESUMEN

This study evaluated the impact of a relationship education program, delivered as part of a college course, among students (N = 152) who reported experiencing psychological aggression in their exclusive dating relationship. Preliminary results showed that compared to those in the control group, participants receiving relationship education were significantly more likely to end their romantic relationship, even after controlling for relationship satisfaction. Furthermore, when relationship termination occurred, those in the intervention group were significantly more likely to attribute the breakup to their participation in the class as compared to those in the control group. The tentative findings are an important preliminary step in assessing the benefits of relationship education in reducing the risk of psychological aggression among college students.

Asunto(s)

RESUMEN

We investigated how power dynamics in close relationships influence the tendency to devote resources to the pursuit of goals valued by relationship partners, hypothesizing that low (vs. high) power in relationships would lead individuals to center their individual goal pursuit around the goals of their partners. We study 2 related phenomena: partner goal prioritization, whereby individuals pursue goals on behalf of their partners, and partner goal contagion, whereby individuals identify and adopt as their own the goals that their partner pursues. We tested our ideas in 5 studies that employed diverse research methods, including lab experiments and dyadic studies of romantic partners, and multiple types of dependent measures, including experience sampling reports, self-reported goal commitment, and behavioral goal pursuit in a variety of goal domains. Despite this methodological diversity, the studies provided clear and consistent evidence that individuals with low power in their relationships are especially likely to engage in both partner goal prioritization and partner goal contagion. (PsycINFO Database Record

Asunto(s)

RESUMEN

BACKGROUND: As global climate change and exponential human population growth intensifies pressure on agricultural systems, the need to effectively manage invasive insect pests is becoming increasingly important to global food security. Drosophila suzukii is an invasive pest that drastically expanded its global range in a very short time since 2008, spreading to most areas in North America and many countries in Europe and South America. Preliminary ecological modeling predicted a more restricted distribution and, for this reason, the invasion of D. suzukii to northern temperate regions is especially unexpected. Investigating D. suzukii phenology and seasonal adaptations can lead to a better understanding of the mechanisms through which insects express phenotypic plasticity, which likely enables invasive species to successfully colonize a wide range of environments. RESULTS: We describe seasonal phenotypic plasticity in field populations of D. suzukii. Specifically, we observed a trend of higher proportions of flies with the winter morph phenotype, characterized by darker pigmentation and longer wing length, as summer progresses to winter. A laboratory-simulated winter photoperiod and temperature (12:12 L:D and 10 °C) were sufficient to induce the winter morph phenotype in D. suzukii. This winter morph is associated with increased survival at 1 °C when compared to the summer morph, thus explaining the ability of D. suzukii to survive cold winters. We then used RNA sequencing to identify gene expression differences underlying seasonal differences in D. suzukii physiology. Winter morph gene expression is consistent with known mechanisms of cold-hardening such as adjustments to ion transport and up-regulation of carbohydrate metabolism. In addition, transcripts involved in oogenesis and DNA replication were down-regulated in the winter morph, providing the first molecular evidence of a reproductive diapause in D. suzukii. CONCLUSIONS: To date, D. suzukii cold resistance studies suggest that this species cannot overwinter in northern locations, e.g. Canada, even though they are established pests in these regions. Combining physiological investigations with RNA sequencing, we present potential mechanisms by which D. suzukii can overwinter in these regions. This work may contribute to more accurate population models that incorporate seasonal variation in physiological parameters, leading to development of better management strategies.

Asunto(s)

RESUMEN

This study investigated aortic and brachial hemodynamic functioning that may link school burnout to cardiovascular risk factors. Methodological improvements from previous research were implemented including (1) statistical control of depressive and anxiety symptoms (2) resting, stress-induced and cardiac recovery condition comparisons and (3) use of pulse wave analysis. Forty undergraduate young adult males completed self-report measures of school burnout, trait anxiety and depressive symptoms. Participants then completed a protocol consisting of a 10-min seated rest, 5-min baseline (BASE), 3-min cold pressor test (CPT) and a 3-min recovery period (REC). Indices of brachial and aortic hemodynamics were obtained by means of pulse wave analysis via applanation tonometry. Controlling for anxiety and depressive symptoms, planned contrasts identified no differences in cardiovascular parameters at BASE between participants in burnout and non-burnout groups. However, negative changes in hemodynamic indices occurred in burnout participants at CPT and REC as evidenced by increased aortic and brachial systolic and diastolic blood pressures, increased left ventricular work and increased myocardial oxygen consumption. Findings suggest that school burnout symptoms are associated with cardiac hyperactivity during conditions of cardiac stress and recovery and therefore may be associated with the early manifestations of cardiovascular disease. Future studies are suggested to reveal underlying autonomic mechanisms explaining hemodynamics functioning in individuals with school burnout symptomatology.

Asunto(s)

RESUMEN

BACKGROUND: Major depressive disorder (MDD) is associated with increased cardiovascular risk. Although cardiovascular hyperactivity to stressors (e.g., cold pressor test (CPT)) is common in those with MDD, the aortic hemodynamic (AH) responses to sympatho-stimulation in healthy individuals with higher depressive scores (HDS) are not well understood. We hypothesized that individuals with HDS, compared with those with low depressive scores (LDS), would have greater changes in AH during the CPT. METHODS: Thirty-five male participants (mean age, 22.3±0.7 years) completed a self-report measure of depressive symptoms and were classified as having an HDS or LDS. Radial waveforms were then obtained by means of applanation tonometry. The testing protocol consisted of a 10-minute seated rest, 5 minutes of baseline measurements, a 3-minute CPT, and a 3-minute recovery period. RESULTS: At baseline, no differences were found between the LDS (n=16) and HDS (n=19) groups on any variables studied. During CPT, there was a significant group-by-time interaction for aortic mean blood pressure (HDS vs. LDS = 107±3mm Hg vs. 96±3mm Hg; P = 0.008); augmentation index (HDS vs. LDS =19% ± 3% vs. 11% ± 2%; P = 0.02), a surrogate of wave reflection; and systolic time interval (HDS vs. LDS = 2295±78mm Hg/s.min(-1) vs. 1919±74mm Hg/s.min(-1); P = 0.001), a marker of myocardial work, such that the HDS group had significantly higher responses than the LDS group. CONCLUSIONS: HDS may be associated with cardiac hyperactivity during sympatho-stimulation, contributing to increased central blood pressure, wave reflection, and myocardial work. Prospective studies to unveil mechanisms explaining increased AH in healthy individuals with high depressive symptomatology are warranted.

Asunto(s)

RESUMEN

Second-generation cobalt and zinc coordination architectures were obtained through efforts to stabilize extremely sensitive and energetic transition-metal hydrazine perchlorate ionic polymers. Partial ligand substitution by the tridentate hydrazinecarboxylate anion afforded polymeric 2D-sheet structures never before observed for energetic materials. Carefully balanced reaction conditions allowed the retention of the noncoordinating perchlorate anion in the presence of a strongly chelating hydrazinecarboxylate ligand. High-quality X-ray single-crystal structure determination revealed that the metal coordination preferences lead to different structural motifs and energetic properties, despite the nearly isoformulaic nature of the two compounds. Energetic tests indicate highly decreased sensitivity and DFT calculations suggest a high explosive performance for these remarkable structures.

RESUMEN

Energetic materials have been used for nearly two centuries in military affairs and to cut labor costs and expedite laborious processes in mining, tunneling, construction, demolition, and agriculture, making a tremendous contribution to the world economy. Yet there has been little advancement in the development of altogether new energetic motifs despite long-standing research efforts to develop superior materials. We report the discovery of new energetic compounds of exceptionally high energy content and novel polymeric structure which avoid the use of lead and mercury salts common in conventional primary explosives. Laboratory tests indicate the remarkable performance of these Ni- and Co-based energetic materials, while DFT calculations indicate that these are possibly the most powerful metal-based energetic materials known to date, with heats of detonation comparable with those of the most powerful organic-based high explosives currently in use.

RESUMEN

The rural surgery rotation that is contained within the general surgery residency program at The University of Tennessee College of Medicine-Chattanooga is described in this article. The advantages of this experience, including the extensive endoscopy experience and the close exposure to practicing general surgeons, are also outlined. The rotation receives uniformly positive evaluations from residents at completion, and it has become the primary gastrointestinal endoscopy educational experience in this program. The description serves as a model that can be used by other programs to construct a rural surgery rotation.

Asunto(s)