Observatoire Cantonal de Neuchâtel

Thanks to its high quadratic nonlinear susceptibilty and low propagation losses, thin film lithium niobate (TFLN) on insulator is an ideal platform for laser frequency conversion and generation of quantum states of light. Frequency conversion is usually achieved by quasi-phase matching (QPM) via electric-field poling. However, this scheme shows very high sensitivity to the dimensions of the waveguide, poling period and duty cycle, resulting in a lack of repeatability of the phase matched wavelength and efficiency, which in turn limits the spread of TFLN frequency converters in complex circuits and hinders wafer-scale production. Here we propose a layer-poled modal phase matching (MPM) that is 5 to 10 times more robust towards fabrication uncertainties and theoretically more efficient than conventional QPM. By selectively poling the bottom part of the waveguide all along its length, second harmonic is efficiently generated on a higher order waveguide's mode. We validate this approach by poling TFLN waveguides as a post-process after the fabrication in a foundry process. We perform a tolerance analysis and compare the experimental results with conventional QPM second harmonic generation process on the same waveguides. Then, we show how MPM can be exploited to obtain efficient intraband frequency conversion processes at telecom wavelengths by leveraging simultaneous second harmonic and difference frequency generation in the same waveguide.

During the early stages of design, mechanisms are commonly modeled as perfect joints assembled with infinitely rigid bodies. This representation enables the prediction of the system’s mobilities through a mobility analysis. However, traditional mobility analysis tools can be computationally expensive or lack critical information, such as the type or direction of mobilities. It hinders the generation of topology and configuration through generative design schemes.In this paper, we propose an alternative approach to mobility analysis based on a real vector space representation of mobilities. Our method provides relevant information for early design steps while being computationally effective through a novel formulation of series and parallel assembly topological operations. A benchmark on four selected use cases highlights an acceleration of 3 to 4 orders of magnitude compared to traditional approaches. Additionally, design rules on the joints’ positions can be automatically generated with our approach. It enables the automation of the complete design process, including topology and configuration. As such, we provide guidelines to develop a generative design scheme dedicated to the synthesis of guiding mechanisms.

When patients are discharged from the hospital and return home, they are at risk of adverse events if the continuity of care is broken. So far, the evidence for transitional care models to reduce readmission rates has focused mainly on patients with a single condition. Based on this observation, we identified the population that may benefit the most from the development of a new transitional care model, as part of the INSTEAD project, by consensus between patients and professionals in hospitals and the community. To ensure continuity of care, it is necessary to consider the patients' perception, their understanding of the care plan and changes impacting the home care plan. Interprofessional collaboration is essential to achieve this.

BackgroundAlthough many success stories exist of Village Health Workers (VHWs) improving primary health care, critiques remain about the medicalisation of their roles in disease-specific interventions. VHWs are placed at the bottom of the health system hierarchy as cheap and low-skilled volunteers, irrespective of their highly valued social and political status within communities. In this paper, we shed light on the political role VHWs play and investigate how this shapes their social and medical roles, including their influence on community participation.MethodThe study was carried out within the context of a malaria elimination trial implemented in rural villages in the North Bank of The Gambia between 2016 and 2018. The trial aimed to reduce malaria prevalence by treating malaria index cases and their potentially asymptomatic compound members, in which VHWs took an active role advocating their community and the intervention, mobilising the population, and distributing antimalarial drugs. Mixed-methods research was used to collect and analyse data through qualitative interviews, group discussions, observations, and quantitative surveys.Results and discussionWe explored the emic logic of participation in a malaria elimination trial and found that VHWs played a pivotal role in representing their community and negotiating with the Medical Research Council to bring benefits (e.g. biomedical care service) to the community. We highlight this representative role of VHWs as ‘health diplomats’, valued and appreciated by community members, and potentially increasing community participation in the trial. We argue that VHWs aspire to be politically present and be part of the key decision-makers in the community through their health diplomat role.ConclusionIt is thus likely that in the context of rural Gambia, supporting VHWs beyond medical roles, in their social and political roles, would contribute to the improved performance of VHWs and to enhanced community participation in activities the community perceive as beneficial.

Dans cette interview Thomas Rohmer évoque les missions de l’Observatoire de la Parentalité et de l'Éducation Numérique. Il décline notamment ses interrogations sur l’approche de la prévention contemporaine vis-à-vis des sexualités et questionne les enjeux de l’application de la loi quant à l’accès aux contenus pornographiques en ligne par les mineurs. Son témoignage reprend différentes initiatives menées en lien avec les décideurs politiques, ce en s’appuyant sur les acteurs culturels des milieux pornographiques. Le parti pris est alors de s’affranchir des approches moralisantes afin d’accompagner l’accès à la sexualité des jeunes.

BackgroundMalaria transmission in The Gambia decreased substantially over the last 20 years thanks to the scale-up of control interventions. However, malaria prevalence is still relatively high in eastern Gambia and represents both a health and a financial burden for households. This study aims to quantify the out-of-pocket costs and productivity losses of seeking malaria treatment at household level.MethodsA household survey was carried out through in-person interviews. Respondents were asked about malaria prevention methods, their treatment-seeking behaviour, and any costs incurred for transport, services, food, and/or overnight stays. A bottom-up costing approach was used to calculate the unit cost of treatment and a tobit regression approach to investigate cost drivers.ResultsThe survey included 864 respondents, mainly subsistence farmers. Most respondents (87%) considered malaria to be a problem affecting their ability to perform their regular duties. Respondents preferred going to a health facility for treatment. The primary reason for not going was related to costs; 70% of respondents incurred costs for seeking health care, with a median of £3.62 (IQR: £1.73 to £6.10). The primary driver of cost was living in one of the villages that are off the main road and/or far from health facilities. 66% reported productivity loss of 5 working days on average during a malaria episode of them or their child.ConclusionsAlthough malaria prevalence is decreasing and treatment is provided free of charge, households seeking treatment are confronted with out-of-pocket expenditures and lost working days; particularly in remote villages.

Integrating mental, neurological, and substance use (MNS) health care into the public health system has become a global priority, with mental health, and well-being now being part of the Sustainable Development Goals. In the aim to provide good quality care for MNS disorders, understanding patients' pathways to care is key. This qualitative study explores the pathways to care of patients attending an outpatient mental health clinic of a district hospital in eastern rural Uganda, from the perspectives of their caregivers. Twenty seven in-depth interviews were conducted with caregivers of MNS patients visiting the clinic, with a focus on four case-presentations. Data analysis consisted of thematic and emergent content analyses using NVivo 11. Results across all interviews highlight that chosen help-seeking itineraries were largely pluralistic, combining and alternating between traditional healing practices, and biomedical care, regardless of the specific MNS disorder. Intra-household differences in care seeking pathways—e.g., where one patient received traditional help or no care at all, while the other received biomedical care—depended on caregivers' perceived contextual illness narrative for each patient, in combination with a variety of other factors. If interpreted as a form of bewitchment, traditional medicine and healing was often the first form of care sought, while the mental health clinic was seen as a recourse to “free” care. Patients, especially younger children, who showed visible improvements once stabilized on psychotropic medication was a source of motivation for caregivers to continue with biomedical care at the mental health clinic. However, stock-outs of the free psychotropic medication at the clinic led to dissatisfaction with services due to out-of-pocket expenses and precipitated returning to alternative therapy choices. This article showcases the importance of understanding the complex and varied combinations of individual, cultural, socioeconomic and structural factors that may affect caregivers' choices of pathways to care for patients with MNS disorders in eastern rural Uganda. These cumulative complex processes and context-specific help-seeking behaviors, which ultimately impact patient treatment and MNS health outcomes, need to be first acknowledged, understood and taken into account if we are to promote more inclusive, effective and integrated public mental health systems globally.

With significant declines in malaria, infections are increasingly clustered in households, or groups of households where malaria transmission is higher than in surrounding household/villages. To decrease transmission in such cases, reactive interventions target household members of clinical malaria cases, with the intervention unit (e.g., the “household/s”) derived from an epidemiological and operational perspective. A lack of unanimity regarding the spatial range of the intervention unit calls for greater importance to be placed on social context in conceptualizing the appropriate unit. A novel malaria elimination strategy based on reactive treatment was recently evaluated by a cluster randomized trial in a low transmission setting in The Gambia. Transdisciplinary research was used to assess and improve the effectiveness of the intervention which consisted, among others, of reflecting on whether the household was the most adequate unit of analysis. The intervention was piloted on the smallest treatment unit possible and was further adapted following a better understanding of the social and epidemiological context. Intervention units defined according to (i) shared sleeping spaces and (ii) household membership, showed substantial limitations as it was not possible to define them clearly and they were extremely variable within the study setting. Incorporating local definitions and community preference in the trial design led to the appropriate intervention unit—the compound—defined as an enclosed space containing one or several households belonging to the same extended patrilineal family. Our study demonstrates the appropriateness of using transdisciplinary research for investigating alternative intervention units that are better tailored to reactive treatment approaches.

Présentation des différents projets de la collection des sources du droit suisse et explication du fonctionnement de ces éditions numériques TEI/XML et de bases de données qui y sont liées.

It is well known that helical magnetic fields undergo a so-called inverse cascade by which their correlation length grows due to the conservation of magnetic helicity in classical ideal magnetohydrodynamics (MHD). At high energies above approximately $10$ MeV, however, classical MHD is necessarily extended to chiral MHD and then the conserved quantity is $\langle\mathcal{H}\rangle + 2 \langle\mu_5\rangle / \lambda$ with $\langle\mathcal{H}\rangle$ being the mean magnetic helicity and $\langle\mu_5\rangle$ being the mean chiral chemical potential of charged fermions. Here, $\lambda$ is a (phenomenological) chiral feedback parameter. In this paper, we study the evolution of the chiral MHD system with the initial condition of nonzero $\langle\mathcal{H}\rangle$ and vanishing $\mu_5$. We present analytic derivations for the time evolution of $\langle\mathcal{H}\rangle$ and $\langle\mu_5\rangle$ that we compare to a series of laminar and turbulent three-dimensional direct numerical simulations. We find that the late-time evolution of $\langle\mathcal{H}\rangle$ depends on the magnetic and kinetic Reynolds numbers ${\rm Re}_{_\mathrm{M}}$ and ${\rm Re}_{_\mathrm{K}}$. For a high ${\rm Re}_{_\mathrm{M}}$ and ${\rm Re}_{_\mathrm{K}}$ where turbulence occurs, $\langle\mathcal{H}\rangle$ eventually evolves in the same way as in classical ideal MHD where the inverse correlation length of the helical magnetic field scales with time $t$ as $k_\mathrm{p} \propto t^{-2/3}$. For a low Reynolds numbers where the velocity field is negligible, the scaling is changed to $k_\mathrm{p} \propto t^{-1/2}\mathrm{ln}\left(t/t_\mathrm{log}\right)$. After being rapidly generated, $\langle\mu_5\rangle$ always decays together with $k_\mathrm{p}$, i.e. $\langle\mu_5\rangle \approx k_\mathrm{p}$, with a time evolution that depends on whether the system is in the limit of low or high Reynolds numbers.