Optical spin-to-orbital angular momentum conversion in ultra-thin metasurfaces with arbitrary topological charges

Orbital angular momentum associated with the helical phase-front of optical beams provides an unbounded \qo{space} for both classical and quantum communications. Among the different approaches to generate and manipulate orbital angular momentum states of light, coupling between spin and orbital angular momentum allows a faster manipulation of orbital angular momentum states because it depends on manipulating the polarisation state of light, which is simpler and generally faster than manipulating conventional orbital angular momentum generators. In this work, we design and fabricate an ultra-thin spin-to-orbital angular momentum converter, based on plasmonic nano-antennas and operating in the visible wavelength range that is capable of converting spin to an arbitrary value of OAM $\ell$. The nano-antennas are arranged in an array with a well-defined geometry in the transverse plane of the beam, possessing a specific integer or half-integer topological charge $q$. When a circularly polarised light beam traverses this metasurface, the output beam polarisation switches handedness and the OAM changes in value by $\ell = \pm2q\hbar$ per photon. We experimentally demonstrate $\ell$ values ranging from $\pm 1$ to $\pm 25$ with conversion efficiencies of $8.6\pm0.4~\%$. Our ultra-thin devices are integratable and thus suitable for applications in quantum communications, quantum computations and nano-scale sensing.Comment: 4 pages, 3 figures - submitted

Barriers, facilitators and views about next steps to implementing supports for evidence-informed decision-making in health systems: a qualitative study

Background: Mobilizing research evidence for daily decision-making is challenging for health system decision-makers. In a previous qualitative paper, we showed the current mix of supports that Canadian health-care organizations have in place and the ones that are perceived to be helpful to facilitate the use of research evidence in health system decision-making. Factors influencing the implementation of such supports remain poorly described in the literature. Identifying the barriers to and facilitators of different interventions is essential for implementation of effective, context-specific, supports for evidence-informed decision-making (EIDM) in health systems. The purpose of this study was to identify (a) barriers and facilitators to implementing supports for EIDM in Canadian health-care organizations, (b) views about emerging development of supports for EIDM, and (c) views about the priorities to bridge the gaps in the current mix of supports that these organizations have in place. Methods: This qualitative study was conducted in three types of health-care organizations (regional health authorities, hospitals, and primary care practices) in two Canadian provinces (Ontario and Quebec). Fifty-seven in-depth semi-structured telephone interviews were conducted with senior managers, library managers, and knowledge brokers from health-care organizations that have already undertaken strategic initiatives in knowledge translation. The interviews were taped, transcribed, and then analyzed thematically using NVivo 9 qualitative data analysis software. Results: Limited resources (i.e., money or staff), time constraints, and negative attitudes (or resistance) toward change were the most frequently identified barriers to implementing supports for EIDM. Genuine interest from health system decision-makers, notably their willingness to invest money and resources and to create a knowledge translation culture over time in health-care organizations, was the most frequently identified facilitator to implementing supports for EIDM. The most frequently cited views about emerging development of supports for EIDM were implementing accessible and efficient systems to support the use of research in decision-making (e.g., documentation and reporting tools, communication tools, and decision support tools) and developing and implementing an infrastructure or position where the accountability for encouraging knowledge use lies. The most frequently stated priorities for bridging the gaps in the current mix of supports that these organizations have in place were implementing technical infrastructures to support research use and to ensure access to research evidence and establishing formal or informal ties to researchers and knowledge brokers outside the organization who can assist in EIDM. Conclusions: These results provide insights on the type of practical implementation imperatives involved in supporting EIDM

What supports do health system organizations have in place to facilitate evidence-informed decision-making? a qualitative study

Background: Decisions regarding health systems are sometimes made without the input of timely and reliable evidence, leading to less than optimal health outcomes. Healthcare organizations can implement tools and infrastructures to support the use of research evidence to inform decision-making. Objectives: The purpose of this study was to profile the supports and instruments (i.e., programs, interventions, instruments or tools) that healthcare organizations currently have in place and which ones were perceived to facilitate evidence-informed decision-making. Methods: In-depth semi-structured telephone interviews were conducted with individuals in three different types of positions (i.e., a senior management team member, a library manager, and a ‘knowledge broker’) in three types of healthcare organizations (i.e., regional health authorities, hospitals and primary care practices) in two Canadian provinces (i.e., Ontario and Quebec). The interviews were taped, transcribed, and then analyzed thematically using NVivo 9 qualitative data analysis software. Results: A total of 57 interviews were conducted in 25 organizations in Ontario and Quebec. The main findings suggest that, for the healthcare organizations that participated in this study, the following supports facilitate evidence-informed decision-making: facilitating roles that actively promote research use within the organization; establishing ties to researchers and opinion leaders outside the organization; a technical infrastructure that provides access to research evidence, such as databases; and provision and participation in training programs to enhance staff’s capacity building. Conclusions: This study identified the need for having a receptive climate, which laid the foundation for the implementation of other tangible initiatives and supported the use of research in decision-making. This study adds to the literature on organizational efforts that can increase the use of research evidence in decision-making. Some of the identified supports may increase the use of research evidence by decision-makers, which may then lead to more informed decisions, and hopefully to a strengthened health system and improved health

Volatolomics in Bacterial Ecotoxicology, A Novel Method for Detecting Signatures of Pesticide Exposure?

Volatile organic compounds (VOC) produced by microorganisms in response to chemical stressor showed recently increasing attention, because of possible environmental applications. In this work, we aimed to bring the first proof of concept that volatolomic (i.e., VOCs analysis) can be used to determine candidate VOC markers of two soil bacteria strains (Pseudomonas fluorescens SG-1 and Bacillus megaterium Mes11) exposure to pesticides. VOC determination was based on solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Accordingly, we highlighted a set of bacterial VOCs modulated in each strains according to the nature of the pesticide used. Three out these VOCs were specifically modulated in P. fluorescens SG-1 when exposed with two pyrethroid pesticides (deltamethrine and cypermethrine): 2-hexanone; 1,3-ditertbutylbenzene and malonic acid, hexyl 3-methylbutyl ester. Our results thus suggest the possible existence of generic VOC markers of pyrethroids in this strain. Of particular interest, two out of these three VOCs, the 1,3-ditertbutylbenzene and the malonic acid, hexyl 3-methylbutyl ester were found also in B. megaterium Mes11 when exposed with cypermethrine. This result highlighted the possible existence of interspecific VOC markers of pyrethroid in these two bacteria. Altogether, our work underlined the relevance of volatolomic to detect signatures of pesticides exposure in microorganisms and more generally to microbial ecotoxicology. Based on these first results, considerations of volatolomics for the chemical risk assessment in environment such as soils can be indirectly explored in longer terms

Relationships between internalized stigma and depression and suicide risk among queer youth in the United States: a systematic review and meta-analysis

Background Queer youth experience high rates of depression and suicidality. These disparities stem from stigma-based stressors, including internalized stigma (i.e., negative social views that minoritized individuals internalize about their own identity). Given the importance of this factor in understanding mental health disparities among queer youth, we completed a systematic review and meta-analysis examining the relationships between internalized stigma and outcomes of depression and suicide risk (i.e., suicidal ideation, non-suicidal self-injury, and suicidal behavior). Methods We followed the PRISMA standards. Six bibliographic databases were searched for studies in the United States from September 2008 to March 2022. Dual independent screening of search results was performed based on a priori inclusion criteria. Results A total of 22 studies were included for data extraction and review. Most studies examined general internalized homophobia, with few examining internalized biphobia or transphobia. Many studies examined depression as an outcome, few studies examined suicidal ideation or behavior, and no studies examined non-suicidal self-injury. Meta-analyses model results show the association between general internalized queer stigma and depressive symptoms ranged r = 0.19, 95% CI [0.14, 0.25] to r = 0.24, 95% CI [0.19, 0.29], the latter reflecting more uniform measures of depression. The association between internalized transphobia and depressive outcomes was small and positive (r = 0.21, 95% CI [−0.24, 0.67]). General internalized queer stigma and suicidal ideation had a very weak positive association (r = 0.07, 95% CI [−0.27, 0.41]) and an even smaller, weaker positive association with suicide attempt (r = 0.02, 95% CI [0.01, 0.03]). Conclusion Implications for clinical practice, policy, and future research are discussed

Relationships between internalized stigma and depression and suicide risk among queer youth in the United States: a systematic review and meta-analysis

BackgroundQueer youth experience high rates of depression and suicidality. These disparities stem from stigma-based stressors, including internalized stigma (i.e., negative social views that minoritized individuals internalize about their own identity). Given the importance of this factor in understanding mental health disparities among queer youth, we completed a systematic review and meta-analysis examining the relationships between internalized stigma and outcomes of depression and suicide risk (i.e., suicidal ideation, non-suicidal self-injury, and suicidal behavior).MethodsWe followed the PRISMA standards. Six bibliographic databases were searched for studies in the United States from September 2008 to March 2022. Dual independent screening of search results was performed based on a priori inclusion criteria.ResultsA total of 22 studies were included for data extraction and review. Most studies examined general internalized homophobia, with few examining internalized biphobia or transphobia. Many studies examined depression as an outcome, few studies examined suicidal ideation or behavior, and no studies examined non-suicidal self-injury. Meta-analyses model results show the association between general internalized queer stigma and depressive symptoms ranged r = 0.19, 95% CI [0.14, 0.25] to r = 0.24, 95% CI [0.19, 0.29], the latter reflecting more uniform measures of depression. The association between internalized transphobia and depressive outcomes was small and positive (r = 0.21, 95% CI [−0.24, 0.67]). General internalized queer stigma and suicidal ideation had a very weak positive association (r = 0.07, 95% CI [−0.27, 0.41]) and an even smaller, weaker positive association with suicide attempt (r = 0.02, 95% CI [0.01, 0.03]).ConclusionImplications for clinical practice, policy, and future research are discussed

Ba4Ru3O10.2(OH)1.8 : a new member of the layered hexagonal perovskite family crystallised from water

A new barium ruthenium oxyhydroxide Ba4Ru3O10.2(OH)1.8 crystallises under hydrothermal conditions at 200 °C: powder neutron diffraction data show it adopts an 8H hexagonal perovskite structure with a new stacking sequence, while high resolution electron microscopy reveals regions of ordered layers of vacant Ru sites, and magnetometry shows antiferromagnetism with TN = 200(5) K

Nautical Research Platform for Water-Bound Experiments

Conducting research in lakes and rivers requires large crews and heavy-duty equipment, making even simple tests more costly and time consuming. Newer research methods are evolving constantly as new technology enables more precise and accessible experiments to be conducted. The need for simple execution of water-bound experiments exists and must be addressed to aid our understanding of these environments. We at the Microgravity Undergraduate Research Team have taken our previous research in autonomous Unmanned Surface Vehicles (USVs) and applied our efforts to relieving this problem. Our current research aims to provide a universal platform for research and experiments to be conducted in lakes and rivers, where we can then expand our efforts to more broad applications. The design allows for remote-control navigation by one user and easy portability. To address precision in experimentation, we have integrated autonomous GPS waypoint navigation which removes user error in sensitive measurements. The most important factor in its design is modularity; the ability to accommodate a wide range of equipment for research. Our platform succeeds in making water-bound experiments more accessible and more precise for a multitude of potential applications

Age-dependent white matter disruptions after military traumatic brain injury: Multivariate analysis results from ENIGMA brain injury

Mild Traumatic brain injury (mTBI) is a signature wound in military personnel, and repetitive mTBI has been linked to age-related neurogenerative disorders that affect white matter (WM) in the brain. However, findings of injury to specific WM tracts have been variable and inconsistent. This may be due to the heterogeneity of mechanisms, etiology, and comorbid disorders related to mTBI. Non-negative matrix factorization (NMF) is a data-driven approach that detects covarying patterns (components) within high-dimensional data. We applied NMF to diffusion imaging data from military Veterans with and without a self-reported TBI history. NMF identified 12 independent components derived from fractional anisotropy (FA) in a large dataset (n = 1,475) gathered through the ENIGMA (Enhancing Neuroimaging Genetics through Meta-Analysis) Military Brain Injury working group. Regressions were used to examine TBI- and mTBI-related associations in NMF-derived components while adjusting for age, sex, post-traumatic stress disorder, depression, and data acquisition site/scanner. We found significantly stronger age-dependent effects of lower FA in Veterans with TBI than Veterans without in four components (q \u3c 0.05), which are spatially unconstrained by traditionally defined WM tracts. One component, occupying the most peripheral location, exhibited significantly stronger age-dependent differences in Veterans with mTBI. We found NMF to be powerful and effective in detecting covarying patterns of FA associated with mTBI by applying standard parametric regression modeling. Our results highlight patterns of WM alteration that are differentially affected by TBI and mTBI in younger compared to older military Veterans

Physiological Correlates of Volunteering

We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation