Reactions of the excited state of polypyridyl chromium(III) ions

The quenching of the [superscript]2E state of CrL[subscript]3[superscript]3+ (where L = 2,2[superscript]\u27-bipyridine, 1,10-phenanthroline and their substituted analogues) by oxalate ions and by the organochromium complexes L[superscript]\u27CrR[superscript]2+ (where L[superscript]\u27 = (15) aneN[subscript]4 and R = primary alkyl, secondary alkyl, arylalkyl) was studied. Also investigated was the reactions of the organochromiums with Ru(bpy)[subscript]3[superscript]3+. Both formation of CrL[subscript]3[superscript]2+ and the loss of [superscript]\*CrL[subscript]3[superscript]3+ can be monitored conveniently enabling the determination of the kinetics as well as the products of the reaction;The reaction of oxalate ions at neutral pH with the excited chromium polypyridyl complexes is an electron transfer process as shown by the trend in rate constants with the one electron reduction potentials of the various [superscript]\*CrL[subscript]3[superscript]3+ species. The quenching reaction apparently proceeds via an ion-pairing pathway. A reactive species is produced in the quench which either produces another equivalent of electron transfer products or a secondary transient depending on the identity of the chromium polypyridyl complex;Reaction of the [superscript]\*CrL[subscript]3[superscript]3+ with the organochromiums appears to be an electron transfer process based on the reactivity pattern in varying the chromium polypyridyl (and consequently the potential) as well as the trend in varying the organic moiety of the L[superscript]\u27CrR[superscript]2+. This last reactivity pattern is that observed in the reactions of the organochromiums and the good outer sphere electron transfer agent, Ru(bpy)[subscript]3[superscript]3+. One electron oxidation of L[superscript]\u27CrR[superscript]2+ produces an unstable species which may undergo a one electron reduction (back electron transfer) or homolyze producing organic radicals

RESILIENCE IN ADOLESCENT AMERICAN STUDENTS

The current study sought to determine if any meaningful relationship existed between perceived mental, emotional/behavioral, and academic resilience and overall resilience in adolescent American students. The current quantitative study was conducting using convenience sampling though a national school counselors’ website. Respondents were asked to respond to a modified version of the ARS-30 resiliency questionnaire as well as respond to a few demographic questions. The findings of the study demonstrated that each aspect of adolescent student resilience (mental, emotional/behavioral, and academic) were statistically significant predictors of overall student resilience; with academic resilience being the most statistically significant predictor of perceived overall resilience in adolescent American students. The findings of the current study give a starting point in measuring American adolescent resilience in the wake of the COVID-19 pandemic. Additionally, the findings of the current study support previous research about the positive outcomes of resilience in students in academic settings

Locomotion of circular robots with diametrically translating legs: Design, analysis, and fabrication

This work develops an analytical basis for designing the locomotion of mobile robots with a circular core and equispaced diametral legs which actuate linearly. Two elementary regimes of motion are first developed using the intrinsic geometry of the mechanism, then combined for fluid motion. The first and primary gait has a path trajectory defined by its kinematic constraints. Dynamics are explored to assist actuator design and understand the mechanism\u27s constraint forces. Simulation results are provided in support of the design concept and geometric optimization. The proposed robot, or Locomotive Amoebic Device (LAD), bears resemblance with certain cellular locomotion, and thus miniaturization is a possibility. A prototype of LAD is constructed which supports the design theory and simulation by executing the primary motion regime with appropriate speed and current settings. Future work is promising for extending the design to a spherical concept, generalizing the theory in terms of the number of legs, creating a variety of control schemes for maneuvers such as dampening phase transitions or pure rolling, equipping and justifying the design for applications such as Planetary Exploration or Medical Procedures, and potentially creating a millimeter scale version or smaller of spherical LAD. This thesis theorizes a unique mode of locomotion and proffers simulation and experimental support

Parenting in sport

This paper provides a brief summary and commentary on the growing literature on parenting in sport, with a particular emphasis on literature from the last 2–3 years. Following a brief introduction overviewing the topic area, we firstly focus on the influence of parental involvement on children. Specifically, we examine the range of factors that influence children's perceptions of parental involvement and the consequences of different behaviors. Next we discuss the factors influencing parental involvement, such as the challenges and stressors associated with parenting children in sport and the culture within different sports. Finally, our review focuses upon the strategies developed by parents to facilitate their involvement in their children's sport, as well as the few papers focused upon parent education and support. We conclude by examining the need for further research and examination of support strategies for parents

Methods to study organogenesis in decapod crustacean larvae. I. larval rearing, preparation, and fixation

Crustacean larvae have served as distinguished models in the field of Ecological Developmental Biology (“EcoDevo”) for many decades, a discipline that examines how developmental mechanisms and their resulting phenotype depend on the environmental context. A contemporary line of research in EcoDevo aims at gaining insights into the immediate tolerance of organisms and their evolutionary potential to adapt to the changing abiotic and biotic environmental conditions created by anthropogenic climate change. Thus, an EcoDevo perspective may be critical to understand and predict the future of organisms in a changing world. Many decapod crustaceans display a complex life cycle that includes pelagic larvae and, in many subgroups, benthic juvenile–adult stages so that a niche shift occurs during the transition from the larval to the juvenile phase. Already at hatching, the larvae possess a wealth of organ systems, many of which also characterise the adult animals, necessary for autonomously surviving and developing in the plankton and suited to respond adaptively to fluctuations of environmental drivers. They also display a rich behavioural repertoire that allows for responses to environmental key factors such as light, hydrostatic pressure, tidal currents, and temperature. Cells, tissues, and organs are at the basis of larval survival, and as the larvae develop, their organs continue to grow in size and complexity. To study organ development, researchers need a suite of state-of-the-art methods adapted to the usually very small size of the larvae. This review and the companion paper set out to provide an overview of methods to study organogenesis in decapod larvae. This first section focuses on larval rearing, preparation, and fixation, whereas the second describes methods to study cells, tissues, and organs

Diversität in der F5 von dynamisch evolvierenden Weizen Composite Cross Populationen

Three winter wheat composite cross (CC) populations were created in 2001 in the UK consisting either of 20 modern wheat parents (called A Population), a subset of 12 high quality parents (Q), or a subset of 9 high yielding parents (Y). Seed of the F4 was transferred to the University of Kassel in 2005 and the populations were grown since then under organic and conventional conditions in well separated large (>100m2) plots in two parallel sets (12 populations total) without conscious selection applied. In the conventional system fungicides and insecticides were not applied to expose the populations to natural pest and disease pressure. Morphological diversity, diseases, and yield were assessed in the field every season. The parents and a total of 1379 single plants of 23 single seed progenies of the F5 were tested in the laboratory for their combined resistance to three brown rust isolates. Only one progeny was homogenous in reaction, all others were mixtures of two to eight three-locus genotypes. Despite the supposed inbreeding structure of wheat one association in the Q progenies was random suggesting recent out-crossing. Thus, diversity and heterogeneity was still high in the F6 with evidence that out-crossing still played a role and contributed to this heterogeneity

Rates of species introduction to a remote oceanic island

The introduction of species to areas beyond the limits of their natural distributions has a major homogenizing influence, making previously distinct biotas more similar. The scale of introductions has frequently been commented on, but their rate and spatial pervasiveness have been less well quantified. Here, we report the findings of a detailed study of pterygote insect introductions to Gough Island, one of the most remote and supposedly pristine temperate oceanic islands, and estimate the rate at which introduced species have successfully established. Out of 99 species recorded from Gough Island, 71 are established introductions, the highest proportion documented for any Southern Ocean island. Estimating a total of approximately 233 landings on Gough Island since first human landfall, this equates to one successful establishment for every three to four landings. Generalizations drawn from other areas suggest that this may be only one-tenth of the number of pterygote species that have arrived at the island, implying that most landings may lead to the arrival of at least one alien. These rates of introduction of new species are estimated to be two to three orders of magnitude greater than background levels for Gough Island, an increase comparable to that estimated for global species extinctions (many of which occur on islands) as a consequence of human activities