NBS-SNI, an extension of the network-based statistic: Abnormal functional connections between important structural actors.

Elucidating the coupling between the structure and the function of the brain and its development across maturation has attracted a lot of interest in the field of network neuroscience in the last 15 years. Mounting evidence supports the hypothesis that the onset of certain brain disorders is linked with the interplay between the structural architecture of the brain and its functional processes, often accompanied with unusual connectivity features. This paper introduces a method called the network-based statistic-simultaneous node investigation (NBS-SNI) that integrates both representations into a single framework, and identifies connectivity abnormalities in case-control studies. With this method, significance is given to the properties of the nodes, as well as to their connections. This approach builds on the well-established network-based statistic (NBS) proposed in 2010. We uncover and identify the regimes in which NBS-SNI offers a gain in statistical resolution to identify a contrast of interest using synthetic data. We also apply our method on two real case-control studies, one consisting of individuals diagnosed with autism and the other consisting of individuals diagnosed with early psychosis. Using NBS-SNI and node properties such as the closeness centrality and local information dimension, we found hypo- and hyperconnected subnetworks and show that our method can offer a 9 percentage points gain in prediction power over the standard NBS.

Millimetric scale two-photon Bessel-Gauss beam light sheet microscopy with three-axis isotropic resolution using an axicon lens.

Significance: Typical light sheet microscopes suffer from artifacts related to the geometry of the light sheet. One main inconvenience is the non-uniform thickness of the light sheet obtained with a Gaussian laser beam. Aim: We developed a two-photon light sheet microscope that takes advantage of a thin and long Bessel-Gauss beam illumination to increase the sheet extent without compromising the resolution. Approach: We use an axicon lens placed directly at the output of an amplified femtosecond laser to produce a long Bessel-Gauss beam on the sample. We studied the dopaminergic system and its projections in a whole cleared mouse brain. Results: Our light sheet microscope allows an isotropic resolution of 2.4 µm in all three axes of the scanned volume while keeping a millimetric-sized field of view, and a fast acquisition rate of up to 34 mm2/s. With slight modifications to the optical setup, the sheet extent can be increased to 6 mm. Conclusion: The proposed system's sheet extent and resolution surpass currently available systems, enabling the fast imaging of large specimens.

Managing the unknown or the art of preventing SARS-CoV-2 infection in workplaces in a context of evolving science, precarious employment, and communication barriers. A qualitative situational analysis in Quebec and Ontario.

Introduction: The issue of communications in the public space, and in particular, in the workplace, became critical in the early stages of the SARS-CoV-2 pandemic and was exacerbated by the stress of the drastic transformation of the organization of work, the speed with which new information was being made available, and the constant fear of being infected or developing a more severe or even fatal form of the disease. Although effective communication is the key to fighting a pandemic, some business sectors were more vulnerable and affected than others, and the individuals in particular socio-demographic and economic categories were proportionately more affected by the number of infections and hospitalizations, and by the number of deaths. Therefore, the aim of this article is to present data related to issues faced by essential workers interacting with the public and their employers to mitigate the contagion of SARS-CoV-2 (COVID-19) at work. Methods: Following the constructivist paradigm, an interpretative qualitative design was used to conduct one-on-one interviews with precarious/low-wage, public-contact workers (N = 40), managers (N = 16), and key informants (N = 16) on topics related to their work environments in the context of COVID-19 prevention. Results: This article has highlighted some aspects of communication in the workplace essential to preventing COVID-19 outbreaks (e.g., access to information in a context of fast-changing instructions, language proficiency, transparency and confidentiality in the workplace, access to clear guidelines). The impact of poor pre-pandemic working relations on crisis management in the workplace also emerged. Discussion: This study reminds us of the need to develop targeted, tailored messages that, while not providing all the answers, maintain dialog and transparency in workplaces.

Endoscopic imaging of white matter fiber tracts using polarization-sensitive optical coherence tomography.

Polarization sensitive optical coherence tomography (PSOCT) has been shown to image and delineate white matter fibers in a label-free manner by revealing optical birefringence within the myelin sheath using a microscope setup. In this proof-of-concept study, we adapt recent advancements in endoscopic PSOCT to perform depth-resolved imaging of white matter structures deep inside intact porcine brain tissue ex-vivo, through a small, rotational fiber probe. The probe geometry is comparable to microelectrodes currently used in neurosurgical interventions. The presented imaging system is mobile, robust, and uses biologically safe levels of optical radiation making it well suited for clinical translation. In neurosurgery, where accuracy is imperative, endoscopic PSOCT through a narrow-gauge fiber probe could provide intra-operative feedback on the location of critical white matter structures.

Ethnocultural Minority Workers and Sustainable Return to Work Following Work Disability: A Qualitative Interpretive Description Study.

Purpose This article provides a state-of-the-art review of issues and factors associated with the sustainable return to work (S-RTW) of ethnocultural minority workers experiencing disability situations attributable to one of four major causes: musculoskeletal disorders, common mental disorders, other chronic diseases or cancer. Methods Using an interpretive description method, an integrative review was conducted of the literature on ethnocultural factors influencing S-RTW issues and factors associated with these four major work-disability causes. An initial review of the 2006-2016 literature was subsequently updated for November 2016-May 2021. To explore and contextualize the results, four focus groups were held with RTW stakeholders representing workplaces, insurers, the healthcare system and workers. Qualitative thematic analysis was performed. Results A total of 56 articles were analyzed and 35 stakeholders participated in four focus groups. Two main findings emerged. First, belonging to an ethnocultural minority group appears associated with cumulative risk factors that may contribute to vulnerability situations and compound the complexity of S-RTW. Second, cultural differences with respect to the prevailing host-country culture may generate communication and trust issues, and conflicts in values and representations, in turn possibly hindering the establishment of positive relationships among all stakeholders and the ability to meet workers' needs. Being a woman in these groups and/or having a lower level of integration into the host country's culture also appear associated with greater S-RTW challenges. Conclusions Based on our findings, we recommend several possible strategies, such as the cultural humility model, for preventing differences from exacerbating the already significant vulnerability situation of some ethnocultural minority workers.

Building a Common Language to Facilitate Discussion Among Stakeholders in Work Disability: A Consensus Group Approach.

PURPOSE: Work disability stakeholders may not share the same understanding and solutions among themselves or with researchers, causing misunderstandings and hindering collaboration regarding solutions for preventing work disability. To reduce such differences, this study sought to build a common vocabulary among stakeholders and researchers, using a transdisciplinary research framework. METHODS: A consensus method based on a constructivist approach was used. A theoretical sampling method was applied to identify researchers or stakeholders representing one of the four systems in the work disability paradigm. A preliminary set of definitions for key terms was assessed using a Web-based questionnaire. It documented participants' level of agreement with each term's inclusion and relevance in the field, and the clarity of the definition, while soliciting suggestions for other terms or clearer definitions. Disagreements were discussed at group meetings, yielding consensus on the final terms and definitions. RESULTS: Eleven stakeholders representing patients, employers, unions, healthcare professionals, and legislative and insurance systems, along with 10 multidisciplinary researchers, participated. The questionnaire yielded initial consensus on the inclusion and definitions of 49 terms, and 109 suggestions mostly for modified definitions (average = 6 suggestions/term). Two preliminary terms were excluded and three terms were added. Ultimately, 80 terms and their definitions yielded consensus. CONCLUSIONS: The process we used to build a common vocabulary was carried out within a transdisciplinary framework. It required a constructivist approach, promoting idea exchanges among participants and co-construction of generally agreed results. The results were rooted in local contexts, thus ensuring the same reference points, regardless of participants' different understandings.

Versatile Microfluidic Platform for Automated Live-Cell Hyperspectral Imaging Applied to Cold Climate Cyanobacterial Biofilms.

Microfluidic bioanalytical platforms are driving discoveries from synthetic biology to the health sciences. In this work, we present a platform for in vivo live-cell imaging and automated species detection in mixed cyanobacterial biofilms from cold climate environments. Using a multimodal microscope with custom optics applied to a chip with six parallel growth channels, we monitored biofilm dynamics via continuous imaging at natural irradiance levels. Machine learning algorithms were applied to the collected hyperspectral images for automatic segmentation of mixed-species biofilms into individual species of cyanobacteria with similar filamentous morphology. The coupling of microfluidic technology with modern multimodal imaging and computer vision systems provides a versatile platform for the study of cause-and-effect scenarios of cyanobacterial biofilms, which are important elements of many ecosystems, including lakes and rivers of the polar regions.

A rapid scoping review of COVID-19 and vulnerable workers: Intersecting occupational and public health issues.

BACKGROUND: This article reports the results of a rapid scoping review of the literature on COVID-19 transmission risk to workers in essential sectors such as retail, health care, manufacturing, and agriculture, and more particularly the experiences of workers in precarious employment and social situations. METHODS: Following scoping review methods, we included 30 studies that varied in terms of methodology and theoretical approaches. The search included peer-reviewed articles and grey literature published between March and September 2020. RESULTS: Based on the studies reviewed, we found that COVID-19 infection and death rates increased not only with age and comorbidities, but also with discrimination and structural inequities based on racism and sexism. Racial and ethnic minority workers, including migrant workers, are concentrated in high-risk occupations and this concentration is correlated to lower socioeconomic conditions. The COVID-19 pandemic appears in the occupational health and safety spotlight as an exacerbator of already existing socioeconomic inequalities and social inequalities in health, especially in light of the intersection of issues related to racism, ethnic minority status, and sexism. CONCLUSIONS: This review provides early evidence about the limitations of institutions' responses to the pandemic, and their capacity to provide a safe and decent working environment for all workers, regardless of their employment status or the social protections they may enjoy under normal circumstances. It is also important to think about these issues in the postpandemic context, when conditions of precariousness and vulnerability persist and possibly worsen.

MCVD-based GRIN-axicon for the generation of scalable Bessel-Gauss beams.

In this Letter, we introduce a graded-index (GRIN)-lens combination named GRIN-axicon, which is a versatile component capable of generating high-quality scalable Bessel-Gauss beams. To the best of our knowledge, the GRIN-axicon is the only optical component that can be introduced in both larger-scale laboratory setups and miniaturized all-fiber optical setups, while having an easy control of the dimensioning of the generated focal line. We show that a GRIN lens with a hyperbolic secant refractive index profile with a sharp central dip and no ripples generates a Bessel-Gauss beam with a high-intensity central lobe when coupled to a simple lens. Such fabrication characteristics are very suitable for the modified chemical vapor deposition (MCVD) process and enable easy manufacturing of an adaptable component that can fit in any optical setup.

How does Gender Influence Sustainable Return to Work Following Prolonged Work Disability? An Interpretive Description Study.

PURPOSE: A sustainable return to work (S-RTW) following prolonged work disability poses different challenges, depending on gender. This article provides a synthesis of gender differences in the issues and factors influencing the S-RTW of workers following such a disability. METHODS: Using an interpretive description method, an integrative review was conducted of the literature on gender differences in S-RTW issues and factors associated with four major causes of work disability. The initial review concerned the 2000-2016 literature; it was subsequently updated for November 2016-March 2020. To explore and contextualise the results, four focus groups were held with stakeholders representing the workplace, insurance, and healthcare systems and workers. Qualitative thematic analysis was performed. RESULTS: A total of 47 articles were reviewed, and 35 stakeholders participated in the focus groups. The prevailing traditional gender roles were found to have a major gender-specific influence on the attitudes, behaviours, processes and outcomes associated with S-RTW. These differences related to the (1) cumulative workload, (2) work engagement, and (3) expressed and addressed needs. CONCLUSIONS: The results highlight the importance of taking into account both professional and personal aspects when integrating gender issues into the assessment of workers' needs and subsequently into interventions.

Tools and tutorial on practical ray tracing for microscopy.

Significance: An advanced understanding of optical design is necessary to create optimal systems but this is rarely taught as part of general curriculum. Compounded by the fact that professional optical design software tools have a prohibitive learning curve, this means that neither knowledge nor tools are easily accessible. Aim: In this tutorial, we introduce a raytracing module for Python, originally developed for teaching optics with ray matrices, to simplify the design and optimization of optical systems. Approach: This module is developed for ray matrix calculations in Python. Many important concepts of optical design that are often poorly understood such as apertures, aperture stops, and field stops are illustrated. Results: The module is explained with examples in real systems with collection efficiency, vignetting, and intensity profiles. Also, the optical invariant, an important benchmark property for optical systems, is used to characterize an optical system. Conclusions: This raytracing Python module will help improve the reader's understanding of optics and also help them design optimal systems.

Insights into the Sustainable Return to Work of Aging Workers with a Work Disability: An Interpretative Description Study.

Purpose A sustainable return to work (S-RTW) following prolonged work disability poses particular challenges as workers age. This article provides a synthesis of the factors and issues involved in a S-RTW process for aging workers following such a disability. Methods Using interpretive description methods, a critical review was conducted of the literature specifying return-to-work factors and issues for aging workers with regard to four major causes of work disability (musculoskeletal disorders, common mental disorders, cancer or other chronic diseases). The initial review concerned the 2000-2016 literature, and was subsequently updated for November 2016-December 2018. To further explore and contextualise the results of this literature review, four focus groups were held with stakeholders, representing the workplace, insurance, and healthcare systems and workers. Qualitative thematic analysis was performed. Results Fifty-five articles were reviewed and 35 stakeholders participated in the focus groups. Returning to work and staying at work appear to be particularly challenging for aging workers, who face notable issues and stigma concerning their ability to meet work demands, as well as their mobilisation and engagement in these processes. Such findings echo in many ways the main assertions of the literature on aging at work, except those regarding the transformation of capacities with aging, which is not mentioned in relation to workers with a work disability. The influence of healthcare and compensation systems on the S-RTW of aging work-disabled workers has also received little attention to date. Conclusions The results underscore that aging workers with a disability are frequently vulnerable in terms of their health or their jobs. Intersectoral efforts are needed to remedy this situation to keep them at work.

Overlapping vulnerabilities in workers of the electronics recycling industry formal sector: A commentary.

Vulnerabilities in workers performing electronics recycling (e-recycling) in the informal sector worldwide have been well documented. However, the growing e-recycling industry in the formal sector still brings many challenges to protect the health of workers and their environment. This commentary aims to draw attention to the overlooked vulnerabilities faced by the workers of the e-recycling industry formal sector in high-income countries and discuss the potential impact on health inequalities experienced by these workers. Expanding the definition of vulnerability, not limited to the biological susceptibility to chemical and physical exposures, the demographic characteristics of workers in the e-recycling formal sector often reveal social groups known to be disadvantaged regarding occupational exposures and health effects, including young workers, immigrant or ethnic minorities, and workers with mental or physical health issues or disabilities. Overlapping structural vulnerabilities of the e-recycling industry stem from its newness, its working conditions, its conditions of employment, and the sociodemographic characteristics of its workforce. This phenomenon in high-income countries is not restricted to the e-recycling industry alone. It is rather a symptom of more generalized macro socioeconomical phenomena. The present challenges are in line with the new gig and green economies and changes in the global market, and their consequences on the solid waste sector. Continued efforts to strengthen the inclusion of social aspects of health into the complex interaction of the structural vulnerabilities met by e-recycling workers will be essential to anticipate and prevent health issues in this essential but still emerging workforce.

Challenges for Therapeutic Applications of Opsin-Based Optogenetic Tools in Humans.

As the technological hurdles are overcome and optogenetic techniques advance to have more control over neurons, therapies based on these approaches will begin to emerge in the clinic. Here, we consider the technical challenges surrounding the transition of this breakthrough technology from an investigative tool to a true therapeutic avenue. The emerging strategies and remaining tasks surrounding genetically encoded molecules which respond to light as well as the vehicles required to deliver them are discussed.The use of optogenetics in humans would represent a completely new paradigm in medicine and would be associated with unprecedented technical considerations. To be applied for stimulation of neurons in humans, an ideal optogenetic tool would need to be non-immunogenic, highly sensitive, and activatable with red light or near-infrared light (to maximize light penetration while minimizing photodamage). To enable sophisticated levels of neuronal control, the combined use of optogenetic actuators and indicators could enable closed-loop all-optical neuromodulation. Such systems would introduce additional challenges related to spectral orthogonality between actuator and indicator, the need for decision making computational algorithms and requirements for large gene cassettes. As in any gene therapy, the therapeutic efficiency of optogenetics will rely on vector delivery and expression in the appropriate cell type. Although viral vectors such as those based on AAVs are showing great potential in human trials, barriers to their general use remain, including immune responses, delivery/transport, and liver clearance. Limitations associated with the gene cassette size which can be packaged in currently approved vectors also need to be addressed.

Rise of Raman spectroscopy in neurosurgery: a review.

SIGNIFICANCE: Although the clinical potential for Raman spectroscopy (RS) has been anticipated for decades, it has only recently been used in neurosurgery. Still, few devices have succeeded in making their way into the operating room. With recent technological advancements, however, vibrational sensing is poised to be a revolutionary tool for neurosurgeons. AIM: We give a summary of neurosurgical workflows and key translational milestones of RS in clinical use and provide the optics and data science background required to implement such devices. APPROACH: We performed an extensive review of the literature, with a specific emphasis on research that aims to build Raman systems suited for a neurosurgical setting. RESULTS: The main translatable interest in Raman sensing rests in its capacity to yield label-free molecular information from tissue intraoperatively. Systems that have proven usable in the clinical setting are ergonomic, have a short integration time, and can acquire high-quality signal even in suboptimal conditions. Moreover, because of the complex microenvironment of brain tissue, data analysis is now recognized as a critical step in achieving high performance Raman-based sensing. CONCLUSIONS: The next generation of Raman-based devices are making their way into operating rooms and their clinical translation requires close collaboration between physicians, engineers, and data scientists.

Anisotropic light scattering from myelinated axons in the spinal cord.

Optogenetics has become an integral tool for studying and dissecting the neural circuitries of the brain using optical control. Recently, it has also begun to be used in the investigation of the spinal cord and peripheral nervous system. However, information on these regions' optical properties is sparse. Moreover, there is a lack of data on the dependence of light propagation with respect to neural tissue organization and orientation. This information is important for effective simulations and optogenetic planning, particularly in the spinal cord where the myelinated axons are highly organized. To this end, we report experimental measurements for the scattering coefficient, validated with three different methods in both the longitudinal and radial directions of multiple mammalian spinal cords. In our analysis, we find that there is indeed a directional dependence of photon propagation when interacting with organized myelinated axons. Specifically, light propagating perpendicular to myelinated axons in the white matter of the spinal cord produced a measured reduced scattering coefficient ( µ s ' ) of 3.52 ± 0.1 mm - 1 , and light that was propagated along the myelinated axons in the white matter produced a measured µ s ' of 1.57 ± 0.03 mm - 1 , across the various species considered. This 50% decrease in scattering power along the myelinated axons is observed with three different measurement strategies (integrating spheres, observed transmittance, and punch-through method). Furthermore, this directional dependence in scattering power and overall light attenuation did not occur in the gray matter regions where the myelin organization is nearly random. The acquired information will be integral in preparing future light-transport simulations and in overall optogenetic planning in both the spinal cord and the brain.

Cortical interneuron-mediated inhibition delays the onset of amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis is a fatal disease resulting from motor neuron degeneration in the cortex and spinal cord. Cortical hyperexcitability is a hallmark feature of amyotrophic lateral sclerosis and is accompanied by decreased intracortical inhibition. Using electrophysiological patch-clamp recordings, we revealed parvalbumin interneurons to be hypoactive in the late pre-symptomatic SOD1*G93A mouse model of amyotrophic lateral sclerosis. We discovered that using adeno-associated virus-mediated delivery of chemogenetic technology targeted to increase the activity of the interneurons within layer 5 of the primary motor cortex, we were able to rescue intracortical inhibition and reduce pyramidal neuron hyperexcitability. Increasing the activity of interneurons in the layer 5 of the primary motor cortex was effective in delaying the onset of amyotrophic lateral sclerosis-associated motor deficits, slowing symptom progression, preserving neuronal populations, and increasing the lifespan of SOD1*G93A mice. Taken together, this study provides novel insights into the pathogenesis and treatment of amyotrophic lateral sclerosis.

Cumulative stigma among injured immigrant workers: a qualitative exploratory study in Montreal (Quebec, Canada).

Purpose: This paper presents the phenomenon of stigmatisation among injured immigrant and ethnocultural minority workers experiencing a long-standing disability. Stigmatisation was one of the main findings of our study, the aim of which was to gain insight into the work rehabilitation process in the context of intercultural relations in Quebec. Various categories of stakeholders took part in the study, which sought to describe their experiences and perspectives and to identify the constraints, barriers, facilitators, and specific needs they encounter in terms of intercultural competencies.Methods: A purposive sample of 40 individuals was selected and divided into four groups: workers (N = 9), clinicians (N = 15), workers' compensation board rehabilitation experts (N = 14), and workplace representatives (N = 2). Semi-structured interviews were conducted using the critical incident technique, combined with an "explicitation" interviewing technique. Data collection and analysis procedures were based on grounded theory.Results: This study shows that immigrant and ethnocultural minority workers may experience stigmatisation as a cumulative process involving different concomitant parts of their "identity": age, gender, social class, ethnicity, mental health, and occupational injuries. Cumulative stigma may aggravate personal distress and feelings of shame, rejection, and disqualification from full social acceptance. Negative anticipatory judgements made by practitioners may undermine the therapeutic relationship and breach mutual trust and confidence.Conclusions: The phenomenon of stigmatisation is well documented in the sociological and health literature, but studies tend to focus on only one type of stigma at a time. Future research should focus on the cumulative process of stigmatisation specifically affecting immigrant and ethnocultural minority workers and its potentially damaging impact on self-concept, healthcare delivery, rehabilitation interventions, and the return to work.Implications for rehabilitationThe repetition of certain clinical situations with people from certain groups should not lead practitioners to undue generalizations, even if they may sometimes be accurate; these generalizations must always be verified on a case by case basis.Ethnicity and culture, along with other social attributions, should serve as working hypotheses or support tools in health communication, not as hindrances to clinical reasoning.Practitioners should deepen their understanding of the patient's treatment expectations and the support available for rehabilitation in his family and community.Stigma in the context of care is linked to the idea of conforming to the proposed institutional models of care (including expected beliefs, attitudes, and behaviours). Therefore, practitioners should be aware that alleged differences, misunderstanding or disagreements can highlight an asymmetry in practitioner-patient power relationships.Organisations should also promote exchange and reflection on how to adapt their institutional models to avoid asymmetrical power relations.Intercultural training should be promoted at the various organisational levels so that managers, decision-makers, and practitioners share a common knowledge of the challenges of intervention in multi-ethnic settings.

A qualitative descriptive study of underground workers who received aluminum dust treatment and its organizational level impact.

From 1943 to 1980, some underground gold and uranium workers in Ontario, Canada were required to inhale aluminum dust for silicosis prevention. Workers were exposed to the dust for up to 30 min daily. This study explored the perceived organizational impact on workers exposed to the aluminum dust treatment in Northeastern Ontario. This qualitative descriptive study included 16 respondents who participated in individual semi-structured interviews. All respondents were Northeastern Ontario workers who were exposed to aluminum dust treatment for at least 1 year. Interviews were transcribed verbatim and analyzed thematically. Themes that emerged were: 1) confidence and trust in companies, 2) lack of participants' and heath care providers' knowledge, and 3) need for compensation and formal apology. Workers' perceived that their long term health was impacted by exposure. The results will be used to help workers, companies, and unions address workplace exposures. The latest information about McIntyre powder will enhance the knowledge about the impact of the exposure.

Convolutional Neural Networks for Spectroscopic Analysis in Retinal Oximetry.

Retinal oximetry is a non-invasive technique to investigate the hemodynamics, vasculature and health of the eye. Current techniques for retinal oximetry have been plagued by quantitatively inconsistent measurements and this has greatly limited their adoption in clinical environments. To become clinically relevant oximetry measurements must become reliable and reproducible across studies and locations. To this end, we have developed a convolutional neural network algorithm for multi-wavelength oximetry, showing a greatly improved calculation performance in comparison to previously reported techniques. The algorithm is calibration free, performs sensing of the four main hemoglobin conformations with no prior knowledge of their characteristic absorption spectra and, due to the convolution-based calculation, is invariable to spectral shifting. We show, herein, the dramatic performance improvements in using this algorithm to deduce effective oxygenation (SO2), as well as the added functionality to accurately measure fractional oxygenation ([Formula: see text]). Furthermore, this report compares, for the first time, the relative performance of several previously reported multi-wavelength oximetry algorithms in the face of controlled spectral variations. The improved ability of the algorithm to accurately and independently measure hemoglobin concentrations offers a high potential tool for disease diagnosis and monitoring when applied to retinal spectroscopy.