38 research outputs found
Predisplacement Abuse and Postdisplacement Factors Associated With mental Health Symptoms After Forced Migration Among Rohingya Refugees in Bangladesh
Importance: At the end of August 2017, violence and persecution in Myanmar\u27s Rakhine state forced nearly 1 million Rohingyas to flee to Bangladesh for their lives and seek shelter. Many refugees, after their traumatic experiences leaving Myanmar, experience mental health problems. Objectives: To identify the prevalence of posttraumatic stress symptoms (PTSSs) among displaced Rohingya adults and investigate the association of predisplacement abuse and postdisplacement factors with PTSSs. Design, setting, and participants: This cross-sectional analysis from a household survey of 1184 Rohingya adults aged 18 years or older was conducted in 8 refugee camps within Cox\u27s Bazar, Bangladesh, from September 17, 2019, to January 11, 2020. Main outcomes and measures: The Impact of Event Scale-Revised was used to assess PTSSs. The possible range of scores was 0 to 88; moderate PTSSs were classified using a score cutoff of 33 to 38 and severe PTSSs were classified using a score cutoff of 39 and above. Adjusted prevalence ratios (aPRs) were estimated using a multivariable logistic regression model adjusted for potential confounders. Results: Of 1184 participants (625 men [52.8%]; mean [SD] age, 35.1 [13.4] years), 552 (46.6%) had severe PTSSs, and 274 (23.1%) had moderate PTSSs. In Bangladesh, refugees are not legally permitted to work in refugees camps, but 276 of 1165 respondents (23.7%) had temporary paid jobs. Moreover, 113 of the 276 working participants (40.9%) and 430 of the 889 nonworking participants (48.4%) reported severe PTSSs. A total of 496 respondents (41.9%) reported inadequate humanitarian aid for their families, and among them, 281 (56.7%) reported severe PTSSs. A total of 136 of 1177 respondents (11.6%) experienced both physical and sexual abuse in Myanmar, and 87 (64.0%) of them had severe PTSSs. The multivariable analysis showed a reduced risk of PTSSs with appropriate humanitarian assistance (aPR, 0.50; CI, 0.38-0.65). Experiencing both physical and sexual abuse before displacement had a significant association with PTSSs (aPR, 2.09; CI, 1.41-3.07). Opportunities for paid employment in refugee camps also reduced the risks of PTSSs (aPR, 0.69; CI, 0.52-0.91)
Cross layer optimization in 4G Wireless mesh networks
Wireless networks have been rapidly evolving over the past two decades. It is foreseen that Fourth generation (4G) wireless systems will involve the integration of wireless mesh networks and the 3G wireless systems such as WCDMA. Moreover their wireless mesh routers will provide service to wireless local networks (WLANs) and possibly incorporate MIMO system and smart admission control policies among others. This integration will not only help the service providers cost effectiveness and users connectivities but will also improve and guarantee the QoS criteria. On the other hand, cross layer design has emerged as a new and major thrust in improving the quality of service (QoS) of wireless networks. Cross layer design involves the interaction of various layers of the network hierarchy which could further improve the QoS of the 4G integrated networks. In this work we seek new techniques for improving the overall QoS of integrated 4G systems. Towards this objective we start with the local low tier WLAN access. We then investigate CDMA alternatives to the TDMA access for wireless mesh networks. Cross layer design in wireless mesh networks is then pursued. In the first phase of this thesis a new access mechanism for WLANs is developed, in which users use an optimum transmission probability obtained by estimating the number of stations from the traffic conditions in a sliding window fashion, thereby increasing the throughput compared to the standard DCF and RTS/CTS mechanism while maintaining the same fairness and the delay performance. In the second phase we introduce a code division multiple access/Time division duplex technique CDMA/TDD for wireless mesh networks, we outline the transmitter and receiver for the relay nodes and evaluate the efficiency, delay and delay jitter performances. This CDMA based technique is more amenable to integrating the two systems (Mesh networks and WCDMA or CDMA 2000 of3G). We compare these results with the TDMA operation and through analysis we prove that the CDMA system outperforms the TDMA counterparts. In the third phase we proceed to an instance of cross layer optimized networks, where we develop an overall optimization routine that finds simultaneously the best route and the best capacity allocation to various nodes. This optimization routine minimizes the average end to end packet delay over all calls subject to various contraints. In the process we use a new adaptive version of Spatial TDMA as a platform for comparison purposes of the MAC techniques involved in the cross layer design. In this phase we also combine CDMA/TDD and optimum routing for cross layer design in wireless mesh networks. We compare the results of the CDMA/TDD system with results obtained from the STDMA system. In our analysis we consider the parallel transmissions of mesh nodes in a mesh topology. These parallel transmissions will increase the capacity resulting in a higher throughput with a lower delay. This will allow the service providers to accommodate more users in their system which will obviously reduce the colt and the end users will enjoy a better service paying a lower amount
Magnetic actuation of microparticles for mass transfer enhancement
The motion of magnetic microparticles (250μm diameter) in a circular microfluidic reactor with a diameter of 10 mm under time dependent magnetic field has been studied using CFD code COMSOL. The effect of actuation protocol on the local and average particle velocity has been investigated. The local Sh numbers were obtained as a function of angular particle position in the range of Re numbers between 0.05 and 10 while the particle velocity was changed over two orders of magnitude. Under time dependent magnetic field, the thickness of the boundary layer continuously changes which results in an increased mass transfer towards the particle surface under periodic particle velocity conditions as compared to steady state velocity conditions. A good agreement between numerical and experimental data has been observed
Key opportunities and challenges for the use of big data in migration research and policy
Migration is one of the defining issues of the 21st century. Better data is required to improve understanding about how and why people are moving, target interventions and support evidence-based migration policy. Big data, defined as large, complex data from diverse sources, has been proposed as a solution to help address current gaps in knowledge. The authors participated in a workshop held in London, UK, in July 2019, that brought together experts from the UN, humanitarian NGOs, policy and academia to develop a better understanding of how big data could be used for migration research and policy. We identified six key areas regarding the application of big data in migration research and policy: accessing and utilising data; integrating data sources and knowledge; understanding environmental drivers of migration; improving healthcare access for migrant populations; ethical and security concerns; and addressing political narratives. We advocate the need for increased cross-disciplinary collaborations to advance the use of big data in migration research whilst safeguarding vulnerable migrant communities
Key opportunities and challenges for the use of big data in migration research and policy
Migration is one of the defining issues of the 21st century. Better data is required to improve
understanding about how and why people are moving, target interventions and support evidencebased
migration policy. Big data, defined as large, complex data from diverse sources, is regularly
proposed as a solution to help address current gaps in knowledge. The authors participated in a
workshop held in London, UK, in July 2019, that brought together experts from the United Nations
(UN), humanitarian non-governmental organisations (NGOs), policy and academia to develop a
better understanding of how big data could be used for migration research and policy. We identified
six key areas regarding the application of big data in migration research and policy: accessing
and utilising data; integrating data sources and knowledge; understanding environmental drivers
of migration; improving healthcare access for migrant populations; ethical and security concerns
around the use of big data; and addressing political narratives. We advocate the need for careful
consideration of the challenges faced by the use of big data, as well as increased cross-disciplinary
collaborations to advance the use of big data in migration research whilst safeguarding vulnerable
migrant communities
Chronic cochlear implantation with and without electric stimulation in a mouse model induces robust cochlear influx of CX3CR1+/GFP macrophages
BACKGROUND: Cochlear implantation is an effective auditory rehabilitation strategy for those with profound hearing loss, including those with residual low frequency hearing through use of hybrid cochlear implantation techniques. Post-mortem studies demonstrate the nearly ubiquitous presence of intracochlear fibrosis and neo-ossification following cochlear implantation. Current evidence suggests post-implantation intracochlear fibrosis is associated with delayed loss of residual acoustic hearing in hybrid cochlear implant (CI) recipients and may also negatively influence outcomes in traditional CI recipients. This study examined the contributions of surgical trauma, foreign body response and electric stimulation to intracochlear fibrosis and the innate immune response to cochlear implantation and the hierarchy of these contributions.
METHODS: Normal hearing CX3CR1
RESULTS: A ST peri-implant cellular infiltrate and fibrosis occurred exclusively in the chronically implanted groups starting on day 7 with a concurrent infiltration of CX3CR1+ macrophages not seen in the other groups. CX3CR1+ macrophage infiltration was seen in the LW and RC in all experimental groups within the first week, being most prominent in the 3 chronically implanted groups during the second and third week.
CONCLUSIONS: The cochlear immune response was most prominent in the presence of chronic cochlear implantation, regardless of electric stimulation level. Further, the development of intracochlear ST fibrosis was dependent on the presence of the indwelling CI foreign body. An innate immune response was evoked by surgical trauma alone (sham and acute CI groups) to a lesser degree. These data suggest that cochlear inflammation and intrascalar fibrosis after cochlear implantation are largely dependent on the presence of a chronic indwelling foreign body and are not critically dependent on electrical stimulation. Also, these data support a role for surgical trauma in inciting the initial innate immune response
Contribution of macrophages to neural survival and intracochlear tissue remodeling responses following cochlear implantation
BACKGROUND: Cochlear implants (CIs) restore hearing to deafened patients. The foreign body response (FBR) following cochlear implantation (post-CI) comprises an infiltration of macrophages, other immune and non-immune cells, and fibrosis into the scala tympani, a space that is normally devoid of cells. This FBR is associated with negative effects on CI outcomes including increased electrode impedances and loss of residual acoustic hearing. This study investigates the extent to which macrophage depletion by an orally administered CSF-1R specific kinase (c-FMS) inhibitor, PLX-5622, modulates the tissue response to CI and neural health.
MAIN TEXT: 10- to 12-week-old CX3CR1 + /GFP Thy1 + /YFP mice on C57BL/6J/B6 background was fed chow containing 1200 mg/kg PLX5622 or control chow for the duration of the study. 7 days after starting the diet, 3-channel cochlear implants were implanted in the ear via the round window. Serial impedance and neural response telemetry (NRT) measurements were acquired throughout the study. Electric stimulation began 7 days post-CI until 28 days post-CI for 5 h/day, 5 days/week, with programming guided by NRT and behavioral responses. Cochleae harvested at 10, 28 or 56 days post-CI were cryosectioned and labeled with an antibody against α-smooth muscle actin (α-SMA) to identify myofibroblasts and quantify the fibrotic response. Using IMARIS image analysis software, the outlines of scala tympani, Rosenthal canal, modiolus, and lateral wall for each turn were traced manually to measure region volume. The density of nuclei, CX3CR1 + macrophages, Thy1 + spiral ganglion neuron (SGN) numbers, and the ratio of the α-SMA + volume/scala tympani volume were calculated. Cochlear implantation in control diet subjects caused infiltration of cells, including macrophages, into the cochlea. Fibrosis was evident in the scala tympani adjacent to the electrode array. Mice fed PLX5622 chow showed reduced macrophage infiltration throughout the implanted cochleae across all time points. However, scala tympani fibrosis was not reduced relative to control diet subjects. Further, mice treated with PLX5622 showed increased electrode impedances compared to controls. Finally, treatment with PLX5622 decreased SGN survival in implanted and contralateral cochleae.
CONCLUSION: The data suggest that macrophages play an important role in modulating the intracochlear tissue response following CI and neural survival
Appetite for Nicotine: An Economic Analysis of Tobacco Control in Bangladesh
The study estimates the economic issues related to tobacco. Cigarette and bidi production in Bangladesh have been increasing since 1980. Imports and exports have fluctuated, but there is a persistent negative trade balance in tobacco and tobacco products. Recent prevalence trends are not clear, but remain over 40% among men. National statistics put smoking among women at 4-5%, but tobacco chewing is common among women, and undocumented. Prevalence is much higher for men with lower incomes and education. Policies to reduce tobacco use are summarized, they have been relatively weak, but would be greatly enhanced if proposed legislation is enacted. Money spent on tobacco products by poor people could do much to reduce malnutrition if it were spent on food instead. Real prices of cigarettes have fallen, and incomes have risen, stimulating consumption. Real price increases would help reduce demand, by 3% for every 10 real price increase. Taxes are relatively low (even for the highest priced, most taxed brands, only 55% of the retail price, plus a 15% value-added tax). Higher taxes would increase total revenues, already 7% of total government revenues. Inadequate data exist to estimate the health care costs attributable to tobacco use in Bangladesh