Salicylaldehyde hydrazones: buttressing of outer sphere hydrogen-bonding and copper-extraction properties

Salicylaldehyde hydrazones are weaker copper extractants than their oxime derivatives, which are used in hydrometallurgical processes to recover ~20 % of the world’s copper. Their strength, based on the extraction equilibrium constant Ke, can be increased by nearly three orders of magnitude by incorporating electron-withdrawing or hydrogen-bond acceptor groups (X) ortho to the phenolic OH group of the salicylaldehyde unit. Density functional theory calculations suggest that the effects of the 3-X substituents arise from a combination of their influence on the acidity of the phenol in the pH-dependent equilibrium, Cu2+ + 2Lorg ⇌ [Cu(L–H)2]org + 2H+, and on their ability to ‘buttress’ interligand hydrogen bonding by interacting with the hydrazone N–H donor group. X-ray crystal structure determination and computed structures indicate that in both the solid state and the gas phase, coordinated hydrazone groups are less planar than coordinated oximes and this has an adverse effect on intramolecular hydrogen-bond formation to the neighbouring phenolate oxygen atoms

Neuropsychiatric features of Parkinson's disease in the era prior to the use of dopaminergic therapies

BACKGROUND: Psychosis in Parkinson's disease includes hallucinations and delusions. Other non-psychotic neuropsychiatric features include depression, anxiety and apathy. There is currently controversy over whether psychosis in Parkinson's is an intrinsic part of the disorder or the result of dopaminergic medications. This study aimed to examine a historical cohort of individuals with Parkinson's prior to the use of dopaminergic therapy to assess the prevalence of psychotic and other neuropsychiatric features. METHODS: The case notes of patients with Parkinson's disease admitted to the National Hospital for Neurology and Neurosurgery, London between 1924 and 1946 were examined. Demographic and clinical variables were extracted along with any neuropsychiatric features. Cases meeting criteria for encephalitis lethargica were excluded. RESULTS: 115 cases of individuals with Parkinson's disease were identified. 58 (41.7%) were female. Mean age was 54.0 (SD 9.6) years and mean time since Parkinson's diagnosis was 5.3 (SD 5.7) years. No individuals met criteria for encephalitis lethargica. No cases of hallucinations or delusions were reported. There was one case of an illusion in a patient who was using anticholinergic medication. Other neuropsychiatric features reported were sleep disorder (present in 10, 8.7%), depression (8, 7.0%), memory impairment (5, 4.3%), impulsivity (4, 3.5%), bradyphrenia (4, 3.5%), impaired attention (3, 2.6%), anxiety (1, 0.9%), fatigue (1, 0.9%) and apathy (1, 0.9%). CONCLUSIONS: Prior to the use of dopaminergic therapies, patients with Parkinson's disease admitted to hospital rarely, if ever, reported psychotic symptoms, although other neuropsychiatric symptoms were more prevalent. The main limitation is that a lack of systematic enquiry about psychotic symptoms may have resulted in underreporting

A Qualitative Evaluation of Mental Health Clinic Staff Perceptions of Barriers and Facilitators to Treating Tobacco Use

Introduction: Veterans with mental health disorders smoke at high rates, but encounter low rates of tobacco treatment. We sought to understand barriers and facilitators to treating tobacco use in VA mental health clinics. Methods: This qualitative study was part of a trial evaluating a telephone care coordination program for smokers using mental health services at six VA facilities. We conducted semi-structured interviews with 14 staff: 12 mental health clinic staff working at the parent study\u27s intervention sites (n = 6 psychiatrists, three psychologists, two social workers, one NP), as well as one psychiatrist and one psychologist on the VA\u27s national tobacco advisory committee. Interviews were transcribed and inductively coded to identify themes. Results: Five barriers themes emerged: (1) competing priorities, (2) patient challenges/resistance, (3) complex staffing/challenging cross-discipline coordination, (4) mixed perceptions about whether tobacco is a mental health care responsibility, and (5) limited staff training/comfort in treating tobacco. Five facilitators themes emerged: (1) reminding mental health staff about tobacco, (2) staff belief in the importance of addressing tobacco, (3) designating a cessation medication prescriber, (4) linking tobacco to mental health outcomes and norms, and (5) limiting mental health staff burden. Conclusions: VA mental health staff struggle with knowing that tobacco use is important, but they face competing priorities, encounter patient resistance, are conflicted on their role in addressing tobacco, and lack tobacco training. They suggested strategies at multiple levels that would help overcome those barriers that can be used to design interventions that improve tobacco treatment delivery for mental health patients. Implications: This study builds upon the existing literature on the high rates of smoking, but low rates of treatment, in people with mental health diagnoses. This study is one of the few qualitative evaluations of mental health clinic staff perceptions of barriers and facilitators to treating tobacco. The study results provide a multi-level framework for developing strategies to improve the implementation of tobacco treatment programs in mental health clinics

Convergent learning algorithms for potential games with unknown noisy rewards

In this paper, we address the problem of convergence to Nash equilibria in games with rewards that are initially unknown and which must be estimated over time from noisy observations. These games arise in many real-world applications, whenever rewards for actions cannot be prespecified and must be learned on-line. Standard results in game theory, however, do not consider such settings. Specifically, using results from stochastic approximation and differential inclusions, we prove the convergence of variants of fictitious play and adaptive play to Nash equilibria in potential games and weakly acyclic games, respectively. These variants all use a multi-agent version of Q-learning to estimate the reward functions and a novel form of the e-greedy decision rule to select an action. Furthermore, we derive e-greedy decision rules that exploit the sparse interaction structure encoded in two compact graphical representations of games, known as graphical and hypergraphical normal form, to improve the convergence rate of the learning algorithms. The structure captured in these representations naturally occurs in many distributed optimisation and control applications. Finally, we demonstrate the efficacy of the algorithms in a simulated ad hoc wireless sensor network management problem

Ligand coordination modulates reductive elimination from aluminium(III)

Oxidative addition to low-valent main-group centres is a major class of reactivity for these species. Here, we present a mechanistic study of the much rarer reverse process – reductive elimination – in Al(iii) systems, and unravel ligand effects in this process.</p

Fossilized skin reveals coevolution with feathers and metabolism in feathered dinosaurs and early birds

Feathers are remarkable evolutionary innovations that are associated with complex adaptations of the skin in modern birds. Fossilised feathers in non-avian dinosaurs and basal birds provide insights into feather evolution, but how associated integumentary adaptations evolved is unclear. Here we report the discovery of fossil skin, preserved with remarkable nanoscale fidelity, in three non-avian maniraptoran dinosaurs and a basal bird from the Cretaceous Jehol biota (China). The skin comprises patches of desquamating epidermal corneocytes that preserve a cytoskeletal array of helically coiled α-keratin tonofibrils. This structure confirms that basal birds and non-avian dinosaurs shed small epidermal flakes as in modern mammals and birds, but structural differences imply that these Cretaceous taxa had lower body heat production than modern birds. Feathered epidermis acquired many, but not all, anatomically modern attributes close to the base of the Maniraptora by the Middle Jurassic

A Primary Care Nurse-Delivered Walking Intervention in Older Adults: PACE (Pedometer Accelerometer Consultation Evaluation)-Lift Cluster Randomised Controlled Trial.

Background: Brisk walking in older people can increase step-counts and moderate to vigorous intensity physical activity (MVPA) in ≥10-minute bouts, as advised in World Health Organization guidelines. Previous interventions have reported step-count increases, but not change in objectively measured MVPA in older people. We assessed whether a primary care nurse-delivered complex intervention increased objectively measured step-counts and MVPA. Methods and Findings: A total of 988 60–75 year olds, able to increase walking and randomly selected from three UK family practices, were invited to participate in a parallel two-arm cluster randomised trial; randomisation was by household. Two-hundred-ninety-eight people from 250 households were randomised between 2011 and 2012; 150 individuals to the intervention group, 148 to the usual care control group. Intervention participants received four primary care nurse physical activity (PA) consultations over 3 months, incorporating behaviour change techniques, pedometer step-count and accelerometer PA intensity feedback, and an individual PA diary and plan. Assessors were not blinded to group status, but statistical analyses were conducted blind. The primary outcome was change in accelerometry assessed average daily step-counts between baseline and 3 months, with change at 12 months a secondary outcome. Other secondary outcomes were change from baseline in time in MVPA weekly in ≥10-minute bouts, accelerometer counts, and counts/minute at 3 months and 12 months. Other outcomes were adverse events, anthropometric measures, mood, and pain. Qualitative evaluations of intervention participants and practice nurses assessed the intervention’s acceptability. At 3 months, eight participants had withdrawn or were lost to follow-up, 280 (94%) individuals provided primary outcome data. At 3 months changes in both average daily step-counts and weekly MVPA in ≥10-minute bouts were significantly higher in the intervention than control group: by 1,037 (95% CI 513–1,560) steps/day and 63 (95% CI 40–87) minutes/week, respectively. At 12 months corresponding differences were 609 (95% CI 104–1,115) steps/day and 40 (95% CI 17–63) minutes/week. Counts and counts/minute showed similar effects to steps and MVPA. Adverse events, anthropometry, mood, and pain were similar in the two groups. Participants and practice nurses found the intervention acceptable and enjoyable. Conclusions : The PACE-Lift trial increased both step-counts and objectively measured MVPA in ≥10-minute bouts in 60–75 year olds at 3 and 12 months, with no effect on adverse events. To our knowledge, this is the first trial in this age group to demonstrate objective MVPA increases and highlights the value of individualised support incorporating objective PA assessment in a primary care setting. Trial Registration: Controlled-Trials.com ISRCTN4212256

Turning up by turning over : the change of scenery effect in major league baseball

Purpose: This study examined a “change of scenery” effect on performance in major league baseball (MLB). We also tested this effect for voluntary versus involuntary employee departures, as well as employees returning to a past employer. Design/Methodology/Approach: This study uses publicly available MLB performance data from 2004 to 2015. The data comprise 712 team changes for players following two consecutive years with the same organization. Data were analyzed using MANCOVA to assess the impact of changing teams on player performance. Findings: Results indicate players with declining performance benefited significantly from a change of scenery. Following a team change, these players experienced a significant increase in their performance that remained stable through a subsequent season. The effect was not different for players who changed teams via trade and free agency and was modest for those returning to a past organization. Analysis also showed that players leaving while their performance was improving suffered a subsequent performance drop-off in the new organization. Implications: As the war for talent escalates and employees change jobs more frequently, extending our understanding of how performance can be influenced by work context may provide new insight into organization staffing policies. Originality/Value: Results extend field theory by highlighting how past performance interacts with new work contexts to influence performance. This is one of the few studies evaluating the job change-performance relationship, and perhaps the first to account for the effects of performance trends prior to exit

MR diffusion changes in the perimeter of the lateral ventricles demonstrate periventricular injury in post-hemorrhagic hydrocephalus of prematurity

OBJECTIVES: Injury to the preterm lateral ventricular perimeter (LVP), which contains the neural stem cells responsible for brain development, may contribute to the neurological sequelae of intraventricular hemorrhage (IVH) and post-hemorrhagic hydrocephalus of prematurity (PHH). This study utilizes diffusion MRI (dMRI) to characterize the microstructural effects of IVH/PHH on the LVP and segmented frontal-occipital horn perimeters (FOHP). STUDY DESIGN: Prospective study of 56 full-term infants, 72 very preterm infants without brain injury (VPT), 17 VPT infants with high-grade IVH without hydrocephalus (HG-IVH), and 13 VPT infants with PHH who underwent dMRI at term equivalent. LVP and FOHP dMRI measures and ventricular size-dMRI correlations were assessed. RESULTS: In the LVP, PHH had consistently lower FA and higher MD and RD than FT and VPT (p\u3c.050). However, while PHH FA was lower, and PHH RD was higher than their respective HG-IVH measures (p\u3c.050), the MD and AD values did not differ. In the FOHP, PHH infants had lower FA and higher RD than FT and VPT (p\u3c.010), and a lower FA than the HG-IVH group (p\u3c.001). While the magnitude of AD in both the LVP and FOHP were consistently less in the PHH group on pairwise comparisons to the other groups, the differences were not significant (p\u3e.050). Ventricular size correlated negatively with FA, and positively with MD and RD (p\u3c.001) in both the LVP and FOHP. In the PHH group, FA was lower in the FOHP than in the LVP, which was contrary to the observed findings in the healthy infants (p\u3c.001). Nevertheless, there were no regional differences in AD, MD, and RD in the PHH group. CONCLUSION: HG-IVH and PHH results in aberrant LVP/FOHP microstructure, with prominent abnormalities among the PHH group, most notably in the FOHP. Larger ventricular size was associated with greater magnitude of abnormality. LVP/FOHP dMRI measures may provide valuable biomarkers for future studies directed at improving the management and neurological outcomes of IVH/PHH