Terahertz plasmonic laser radiating in an ultra-narrow beam

Plasmonic lasers (spasers) generate coherent surface-plasmon-polaritons (SPPs) and could be realized at subwavelength dimensions in metallic cavities for applications in nanoscale optics. Plasmonic cavities are also utilized for terahertz quantum-cascade lasers (QCLs), which are the brightest available solid-state sources of terahertz radiation. A long standing challenge for spasers is their poor coupling to the far-field radiation. Unlike conventional lasers that could produce directional beams, spasers have highly divergent radiation patterns due to their subwavelength apertures. Here, we theoretically and experimentally demonstrate a new technique for implementing distributed-feedback (DFB) that is distinct from any other previously utilized DFB schemes for semiconductor lasers. The so-termed antenna-feedback scheme leads to single-mode operation in plasmonic lasers, couples the resonant SPP mode to a highly directional far-field radiation pattern, and integrates hybrid SPPs in surrounding medium into the operation of the DFB lasers. Experimentally, the antenna-feedback method, which does not require the phase matching to a well-defined effective index, is implemented for terahertz QCLs, and single-mode terahertz QCLs with beam divergence as small as 4 x 4 degree are demonstrated, which is the narrowest beam reported for any terahertz QCL to-date. Moreover, in contrast to negligible radiative-field in conventional photonic band-edge lasers, in which the periodicity follows the integer multiple of half-wavelength inside active medium, antenna-feedback breaks this integer-limit for the first time and enhances the radiative-field of lasing mode. The antenna-feedback scheme is generally applicable to any plasmonic laser with a Fabry-Perot cavity irrespective of its operating wavelength, and could bring plasmonic lasers closer to practical applications

A dynamic basal complex modulates mammalian sperm movement

Centrioles are ancient organelles with a conserved architecture and their rigidity is thought to restrict microtubule sliding. Here authors show that, in mammalian sperm, the atypical distal centriole and its surrounding atypical pericentriolar matrix form a dynamic basal complex that facilitates a cascade of internal sliding deformations, coupling tail beating with asymmetric head kinking

Challenges and opportunities in the implementation of an antimicrobial stewardship program in Nepal

Antimicrobial resistance (AMR) continues to be a serious global public issue. Unnecessary and inappropriate use of antimicrobials has been identified as a major contributing factor for AMR. Implementation of antimicrobial stewardship programs (ASPs) is valued as a key strategy to combat AMR. Although ASP is a key intervention to improve appropriate use of antibiotics, there is limited experience and research to describe its implementation in low-income countries such as Nepal. Grande International Hospital (GIH) is the first health organization in Nepal to implement and sustain a multidisciplinary ASP and infection control program. Challenges faced in implementing ASP include lack of acceptance from physicians, lack of knowledge regarding antibiotic prescribing, lack of staff for ASP activities, limitations in diagnostic testing to inform ASP, and limitations in antibiotic choice due to antibiotic unavailability. Our ASP includes the following components: an ASP committee, an antibiotic prescribing reference guide with dosage recommendations, inpatient formulary restriction system, educational outreach and programming for physicians and other stakeholders, and periodic review and revision of the program and reference guide. The ASP provided opportunities to address several knowledge gaps across our healthcare institution including improved knowledge and competency regarding rational use of antibiotics, access to quality medicines and better care to patients. It is our hope that, by describing the challenges and opportunities we experienced while implementing our ASP, we can support and encourage other institutions to adapt and implement ASPs in Nepal and other resource-limited settings

Understanding implementation and feasibility of tobacco cessation in routine primary care in Nepal: a mixed methods study

Background: By 2030, 80 % of the annual 8.3 million deaths attributable to tobacco will be in low-income countries (LICs). Yet, services to support people to quit tobacco are not part of routine primary care in LICs. This study explored the challenges to implementing a behavioural support (BS) intervention to promote tobacco cessation within primary care in Nepal. Methods: The study used qualitative and quantitative methods within an action research approach in three primary health care centres (PHCCs) in two districts of Nepal. Before implementation, 21 patient interviews and two focus groups with health workers informed intervention design. Over a 6-month period, two researchers facilitated action research meetings with staff and observed implementation, recording the process and their reflections in diaries. Patients were followed up 3 months after BS to determine tobacco use (verified biochemically) and gain feedback on the intervention. A further five interviews with managers provided reflections on the process. The qualitative analysis used Normalisation Process Theory (NPT) to understand implementation. Results: Only 2 % of out-patient appointments identified the patient as a smoker. Qualitative findings highlight patients' unwillingness to admit their smoking status and limited motivation among health workers to offer the intervention. Patient-centred skills needed for BS were new to staff, who found them challenging particularly with low-literacy patients (skill set workability). Heath workers saw cessation advice and BS as an addition to their existing workload (relational integration). While there was strong policy buy-in, operationalising this through reporting and supervision was limited (contextual integration). Of the 44 patients receiving the intervention, 27 were successfully followed up after 3 months; 37 % of these had quit (verified biochemically). Conclusions: Traditionally, primary health care in LICs has focused on acute care; with increasing recognition of the need for lifestyle change, health workers must develop new skills and relationships with patients. Appropriate and regular recording, reporting, supervision and clear leadership are needed if health workers are to take responsibility for smoking cessation. The consistent implementation of these health system activities is a requirement if cessation services are to be normalised within routine primary care

Addressing unintentional exclusion of vulnerable and mobile households in traditional surveys in Kathmandu, Dhaka and Hanoi : a mixed methods feasibility study

The methods used in low- and middle-income countries’ (LMICs) household surveys have not changed in four decades; however, LMIC societies have changed substantially and now face unprecedented rates of urbanization and urbanization of poverty. This mismatch may result in unintentional exclusion of vulnerable and mobile urban populations. We compare three survey method innovations with standard survey methods in Kathmandu, Dhaka, and Hanoi and summarize feasibility of our innovative methods in terms of time, cost, skill requirements, and experiences. We used descriptive statistics and regression techniques to compare respondent characteristics in samples drawn with innovative versus standard survey designs and household definitions, adjusting for sample probability weights and clustering. Feasibility of innovative methods was evaluated using a thematic framework analysis of focus group discussions with survey field staff, and via survey planner budgets. We found that a common household definition excluded single adults (46.9%) and migrant-headed households (6.7%), as well as non-married (8.5%), unemployed (10.5%), disabled (9.3%), and studying adults (14.3%). Further, standard two-stage sampling resulted in fewer single adult and non-family households than an innovative area-microcensus design; however, two-stage sampling resulted in more tent and shack dwellers. Our survey innovations provided good value for money, and field staff experiences were neutral or positive. Staff recommended streamlining field tools and pairing technical and survey content experts during fieldwork. This evidence of exclusion of vulnerable and mobile urban populations in LMIC household surveys is deeply concerning and underscores the need to modernize survey methods and practices

Operationalisation of the Randomized Embedded Multifactorial Adaptive Platform for COVID-19 trials in a low and lower-middle income critical care learning health system

The Randomized Embedded Multifactorial Adaptive Platform (REMAP-CAP) adapted for COVID-19) trial is a global adaptive platform trial of hospitalised patients with COVID-19. We describe implementation in three countries under the umbrella of the Wellcome supported Low and Middle Income Country (LMIC) critical care network: Collaboration for Research, Implementation and Training in Asia (CCA). The collaboration sought to overcome known barriers to multi centre-clinical trials in resource-limited settings. Methods described focused on six aspects of implementation: i, Strengthening an existing community of practice; ii, Remote study site recruitment, training and support; iii, Harmonising the REMAP CAP- COVID trial with existing care processes; iv, Embedding REMAP CAP- COVID case report form into the existing CCA registry platform, v, Context specific adaptation and data management; vi, Alignment with existing pandemic and critical care research in the CCA. Methods described here may enable other LMIC sites to participate as equal partners in international critical care trials of urgent public health importance, both during this pandemic and beyond

Surveys for Urban Equity

This dataset contains results and documentation from three cross-sectional urban household surveys done in Kathmandu (Nepal), Dhaka (Bangladesh) and Hanoi (Vietnam) in 2017 and 2018. The surveys primarily aimed to test the feasibility of using new urban household survey methods that try to better cover/capture informal/slum settlements using sampling frame data generated from random forest models that incorporate census data (which is often outdated and inaccurate) with multiple remotely-sensed covariates, such as urbanisation and infrastructure data. Additionally, the surveys also aimed to gather data on a range of topics including many that are not commonly collected in household surveys, particularly of urban areas: A) basic socio-demographic details of household members, B) household characteristics, assets, income and expenses, C) household migration and social capital, D) household member injury and injury related death, and, for one individual per household, E) migration, social capital and depression/mental health. See the "Readme - dataset file descriptions.docx” file for a description of all files and datasets available, plus additional relevant references

Development of a Patient-Centred, Psychosocial Support Intervention for Multi-Drug-Resistant Tuberculosis (MDR-TB) Care in Nepal

Multi-drug-resistant tuberculosis (MDR-TB) poses a major threat to public health worldwide, particularly in low-income countries. The current long (20 month) and arduous treatment regime uses powerful drugs with side-effects that include mental ill-health. It has a high loss-to-follow-up (25%) and higher case fatality and lower cure-rates than those with drug sensitive tuberculosis (TB). While some national TB programmes provide small financial allowances to patients, other aspects of psychosocial ill-health, including iatrogenic ones, are not routinely assessed or addressed. We aimed to develop an intervention to improve psycho-social well-being for MDR-TB patients in Nepal. To do this we conducted qualitative work with MDR-TB patients, health professionals and the National TB programme (NTP) in Nepal. We conducted semi-structured interviews (SSIs) with 15 patients (10 men and 5 women, aged 21 to 68), four family members and three frontline health workers. In addition, three focus groups were held with MDR-TB patients and three with their family members. We conducted a series of meetings and workshops with key stakeholders to design the intervention, working closely with the NTP to enable government ownership. Our findings highlight the negative impacts of MDR-TB treatment on mental health, with greater impacts felt among those with limited social and financial support, predominantly married women. Michie et al's (2011) framework for behaviour change proved helpful in identifying corresponding practice- and policy-level changes. The findings from this study emphasise the need for tailored psycho-social support. Recent work on simple psychological support packages for the general population can usefully be adapted for use with people with MDR-TB

Public Health Risks in Urban Slums : Findings of the Qualitative 'Healthy Kitchens Healthy Cities' Study in Kathmandu, Nepal

BACKGROUND: Communities in urban slums face multiple risks to their health. These are shaped by intermediary and structural determinants. Gaining a clear understanding of these determinants is a prerequisite for developing interventions to reduce the health consequences of urban poverty. With 828 million people living in slum conditions, the need to find ways to reduce risks to health has never been greater. In many low income settings, the kitchen is the epicentre of activities and behaviours which either undermine or enhance health. METHODS: We used qualitative methods of semi-structured interviews, observation and participatory workshops in two slum areas in Kathmandu, Nepal to gain women's perspectives on the health risks they faced in and around their kitchens. Twenty one women were interviewed and four participatory workshops with a total of 69 women were held. The women took photographs of their kitchens to trigger discussions. FINDINGS: The main health conditions identified by the women were respiratory disease, gastrointestinal disease and burn injuries. Women clearly understood intermediary (psychosocial, material and behavioural) determinants to these health conditions such as poor ventilation, cooking on open fires, over-crowding, lack of adequate child supervision. Women articulated the stress they experienced and clearly linked this to health conditions such as heart disease and uptake of smoking. They were also able to identify protective factors, particularly social capital. Subsequent analysis highlighted how female headed-households and those with disabilities had to contend with greater risks to health. CONCLUSIONS: Women living in slums are very aware of the intermediary determinants-material, behavioural and psycho-social, that increase their vulnerability to ill health. They are also able to identify protective factors, particularly social capital. It is only by understanding the determinants at all levels, not just the behavioural, that we will be able to identify appropriate interventions

Health worker and patient views on implementation of smoking cessation in routine tuberculosis care

Böckmann M, Warsi S, Noor M, et al. Health worker and patient views on implementation of smoking cessation in routine tuberculosis care. NPJ primary care respiratory medicine. 2019;29(1): 34.Smoking worsens tuberculosis (TB) outcomes. Persons with TB who smoke can benefit from smoking cessation. We report findings of a multi-country qualitative process evaluation assessing barriers and facilitators to implementation of smoking cessation behaviour support in TB clinics in Bangladesh and Pakistan. We conducted semi-structured qualitative interviews at five case study clinics with 35 patients and 8 health workers over a period of 11 months (2017-2018) at different time points during the intervention implementation phase. Interviews were conducted by trained researchers in the native languages, audio-recorded, transcribed into English and analysed using a combined deductive-inductive approach guided by the Consolidated Framework for Implementation Research and Theoretical Domains Framework. All patients report willingness to quit smoking and recent quit attempts. Individuals' main motivations to quit are their health and the need to financially provide for a family. Behavioural regulation such as avoiding exposure to cigarettes and social influences from friends, family and colleagues are main themes of the interviews. Most male patients do not feel shy admitting to smoking, for the sole female patient interviewee stigma was an issue. Health workers report structural characteristics such as high workload and limited time per patient as primary barriers to offering behavioural support. Self-efficacy to discuss tobacco use with women varies by health worker. Systemic barriers to implementation such as staff workload and socio-cultural barriers to cessation like gender relations, stigma or social influences should be dealt with creatively to optimize the behaviour support for sustainability and scale-up