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Migration is in the news every day. Whether it be the plight of refugees fleeing Syria, or the outbreak of the Zika virus across Latin America, the modern world is fundamentally shaped by movement across borders. Migration, arising from the 2018 Darwin College Lectures, brings together eight leading scholars across the arts, humanities, and sciences to help tackle one of the most important topics of our time. What is migration? How has it changed the world? And how will it shape the future? The authors approach these questions from a variety of perspectives, including history, politics, epidemiology, and art. Chapters related to policy, as well as those written by leading journalists and broadcasters, give perspective on how migration is understood in the media, and engage the public more widely. This interdisciplinary approach provides an original take on migration, providing new insights into the making of the modern world.
Pott's puffy tumour is a rare complication of sinusitis. This osteomyelitis can affect the outer and inner tables of the frontal sinus. The treatment of Pott's puffy tumour combines medical and surgical approaches. Surgical approaches have traditionally been open, but endoscopic techniques have been adopted recently in select cases. The bony defect from debridement can be left alone, or closed with autografts or allografts.
To describe a technique for the reconstruction of a large skull vault after the debridement of extensive osteomyelitis of the anterior cranial vault.
Modified distraction osteogenesis is used in the cranial vault, to induce new bone formation. This is customarily used to lengthen long bones. The advantages of this technique include avoiding autologous grafts or alloplastic cranioplasty in the infected surgical bed, and allowing primary closure.
Early post-operative imaging results have been encouraging, with no reported complications.
Modified distraction osteogenesis is a novel technique in the primary reconstruction of calvarial bone.
Capillary rise of a liquid displacing gas is analysed for both open and closed capillaries. We include menisci mass and hysteresis, and show that oscillations due to inertia are muted by friction at the advancing meniscus. From single-phase numerical computations in a no-slip/slip capillary, we quantify losses due to entry, flow development, meniscus slip, exit and acceleration of fluid within the reservoir. For closed capillaries, determining viscous drag due to gas requires inclusion of compressibility, and solving a moving boundary problem. This solution is derived through perturbation expansion with respect to two different small parameters for obtaining pressure above the liquid meniscus. Our rise predictions spanning a large range of experimental conditions and fluids for both open and closed capillaries match the data. The experimental data confirm the adequacy of the theoretically constructed dimensionless groups for predicting oscillatory behaviour.
Both India and Nepal are prone to a wide range of natural and man-made disasters. Almost 85% of India’s area is vulnerable to one or more hazards, and more than 80% of the total population of Nepal is at risk of natural hazards. In terms of the number of people affected in reported disastrous events, India is in the top 10 and Nepal is in the top 20 globally. Over the last two decades, India and Nepal have taken steps to establish their respective National Disaster Management organizations, which provide essential disaster responses. However, key gaps still remain in trained clinical capacity for managing impacts from various disasters. Our review of the region has shown that large parts of the population suffer injuries, diseases, disabilities, psychosocial, and other health-related problems from disasters.
Develop disaster medicine clinical capacity to reduce morbidities and mortalities from disasters.
Independent published data and work undertaken by the lead author in various disasters in India and Nepal since 1993 formed the basis of establishing the Faculty of Disaster Medicine for South Asia. The Faculty of Disaster Medicine - India and Nepal (FDMIN) was launched from Pune in March 2015. This initiative is supported by the National Association of Primary Care (UK), Public Health England, Faculty of Pre-hospital Care of Royal College of Surgeons - Edinburgh and CRIMEDIM (Novara) - Italy.
FDMIN has international expert advisors and has outlined 16 modules training curriculum for health care professionals. FDMIN currently has partnerships for teaching disaster medicine program with 3 medical universities and 12 major health care providers. Six pilot training programmes have been conducted in Pune, Delhi, Chennai, and Kochin. Work is underway to submit an application to the Indian regulatory bodies for approval to establish a post-graduate diploma and Master’s for Disaster Medicine.
We have successfully employed a charge transfer mechanism to convert carbon nanotube (CNT) powder into CNT flexible membrane with no binder. We have demonstrated the use of the CNT membranes as electrode in a stacked bipolar solid-state capacitor using grafoil as current collector that showed 80% capacitance retention over 10,000 cycles at 70 °C. The CNT membranes could have potential application in catalysis, photovoltaic, thermoelectric, and many others.
This work investigates analytically, the use of piezoelectric tiles placed on stairways for vibrational energy harvesting – harnessing electrical power from natural vibrational phenomena – from pedestrian footfalls. While energy harvesting from pedestrian traffic along flat pathways has been studied in the linear regime and realised in practical applications, the greater amounts of energy naturally expended in traversing stairways suggest better prospects for harvesting. Considering the characteristics of two types of commercially available piezoelectric tiles – Navy Type III and Navy Type V – analytical models for the coupled electromechanical system are formulated. The harvesting potential of the tiles is then studied under conditions of both deterministic and carefully developed random excitation profiles for three distinct cases: linear, monostable nonlinear and an array of monostable nonlinear tiles on adjacent steps with linear coupling between them. The results indicate enhanced power output when the tiles are: (1) placed on stairways, (2) uncoupled and (3) subjected to excitation profiles with stochastic frequency. In addition, the Navy Type V tiles are seen to outperform the Navy Type III tiles. Finally, the strongly nonlinear regime outperforms the linear one suggesting that the realisation of commercially available piezoelectric tiles with appropriately tailored nonlinear characteristics will likely have a significant impact on energy harvesting from pedestrian traffic.
Vibration energy harvesting aims to harness the energy of ambient random vibrations for power generation, particularly in small-scale devices. Typically, stochastic excitation driving the harvester is modelled as a Brownian process and the dynamics are studied in the equilibrium state. However, non-Brownian excitations are of interest, particularly in the nonequilibrium regime of the dynamics. In this work we study the nonequilibrium dynamics of a generic piezoelectric harvester driven by Brownian as well as (non-Brownian) Lévy flight excitation, both in the linear and the Duffing regimes. Both the monostable and the bistable cases of the Duffing regime are studied. The first set of results demonstrate that Lévy flight excitation results in higher expectation values of harvested power. In particular, it is shown that increasing the noise intensity leads to a significant increase in power output. It is also shown that a linearly coupled array of nonlinear harvesters yields improved power output for tailored values of coupling coefficients. The second set of results show that Lévy flight excitation fundamentally alters the bifurcation characteristics of the dynamics. Together, the results underscore the importance of non-Brownian excitation characterised by Lévy flight in vibration energy harvesting, both from a theoretical viewpoint and from the perspective of practical applications.
Probabilistic Logic Programs (PLPs) generalize traditional logic programs and allow the encoding of models combining logical structure and uncertainty. In PLP, inference is performed by summarizing the possible worlds which entail the query in a suitable data structure, and using this data structure to compute the answer probability. Systems such as ProbLog, PITA, etc., use propositional data structures like explanation graphs, BDDs, SDDs, etc., to represent the possible worlds. While this approach saves inference time due to substructure sharing, there are a number of problems where a more compact data structure is possible. We propose a data structure called Ordered Symbolic Derivation Diagram (OSDD) which captures the possible worlds by means of constraint formulas. We describe a program transformation technique to construct OSDDs via query evaluation, and give procedures to perform exact and approximate inference over OSDDs. Our approach has two key properties. Firstly, the exact inference procedure is a generalization of traditional inference, and results in speedup over the latter in certain settings. Secondly, the approximate technique is a generalization of likelihood weighting in Bayesian Networks, and allows us to perform sampling-based inference with lower rejection rate and variance. We evaluate the effectiveness of the proposed techniques through experiments on several problems.
Research demonstrates the importance of nutrition for early brain development. Few studies have examined the effectiveness of multiple micronutrient powders (MNP) on child development. This study examined the impacts of home fortification with MNP on motor and mental development, executive function and memory of children living in Bihar. This two-arm cluster-randomised effectiveness trial selected seventy health sub-centres to receive either MNP and nutrition counselling (intervention) or nutrition counselling alone (control) for 12 months. Front-line health workers delivered the intervention to all households in study communities with a child aged 6–18 months. Data were collected using cross-sectional surveys at baseline and endline by selecting households from intervention (baseline, n 2184; endline, n 2170) and control (baseline, n 2176; endline, n 2122) communities using a two-stage cluster-randomised sampling strategy. Children in the intervention group had a significantly larger improvement from baseline to endline compared with those in the control group on scores for motor and mental development (Cohen’s d, motor=0·12; 95 % CI 0·03, 0·22; mental=0·15; 95 % CI 0·06, 0·25). Greater impacts of MNP on motor and mental development were observed in children from households with higher stimulation scores at baseline compared with those with lower stimulation (Cohen’s d, motor=0·20 v. 0·09; mental=0·22 v. 0·14; Pinteraction<0·05). No significant treatment differences were seen for executive function or memory. Home fortification with MNP through the existing health infrastructure in Bihar was effective in improving motor and mental development and should be considered in combination with other child development interventions such as stimulation.
A hierarchical porous carbon with bimodal pore size distribution was synthesized using pyrolysis and controlled activation of polymer gel derived from furfuryl alcohol and phloroglucinol using a soft templating approach. Symmetric capacitors made using the synthesized carbon electrodes in neat 1-butyl 3-methylimidazolium tetrafluoroborate showed a specific capacitance of 141 F/g at 1 A/g when cycled between 0 and 3.8 V at room temperature. The capacitor also showed 90% capacitance retention over 5000 cycles. Equivalent circuit modeling of impedance spectra was done to monitor changes and provide microstructural details during cycling and temperature studies. Cyclic voltammetry showed the presence of specific adsorption of the electrolyte ions on the carbon electrode and this was in good agreement with strong dependence of specific capacitance on temperature. Such strong interaction along with the nature of electrical double layer formed in the hierarchical porous carbon results in widening the voltage stability window of the capacitor.
Our understanding of the politics of race, indigeneity, and ethnicity is informed not only by the work of scholars, but also by the work of leaders and practitioners, many of whom are pioneers in their respective fields. The Journal of Race, Ethnicity, and Politics (JREP) is proud to continue our Q&A series with Steve Phillips, founder of Democracy in Color, an organization focused on race and politics, and author of the New York Times and Washington Post bestselling book, Brown Is the New White: How the Demographic Revolution Has Created a New American Majority. Our hope is that forums like these will help advance our collective scholarship by better informing our research agendas, validating some of our claims, and building more bridges between the worlds of research, politics, and policy.
Arterial switch operation is the treatment of choice in infants with transposed arterial trunks. It is technically challenging to perform in patients having usual atrial arrangement and concordant atrioventricular connections but having a left-sided aorta. Correction in this setting requires surgical expertise and precision. Here we review our experience with such patients.
Between January, 2002 and October, 2013, the arterial switch operation was performed in 20 patients in the combination emphasised above. Patient records were analysed in detail for coronary arterial patterns, and for the techniques used for transfer of the coronary arteries and reconstruction of the great arteries. Outcomes were recorded in terms of in-hospital survival and left ventricular function at the most recent follow-up.
All patients survived the procedure. Ages ranged from 3 days to 18 months, with a median of 75 days; the weight of the patients ranged from 3 to 8.8 kg, with a median of 3.85 kg. The LeCompte manoeuvre was performed in only nine patients. The mean cardiopulmonary bypass time was 157.5±24.9, with a median of 161 minutes, and the mean aortic cross-clamp time was 101.2±23.8, with a median of 102 minutes. Subsequently, two patients died: the first due to a sudden onset of ventricular fibrillation and the second during a crisis of severe pulmonary hypertension. At the last follow-up, which ranged from 23 to 41 months, with a mean of 38.04±2.32 and a median of 38.4 months, all 18 survivors were in NYHA class I, with none requiring cardiac medications and all having normal bi-ventricular function without residual defects.
With appropriate technical modifications, patients with concordant atrioventricular and discordant ventriculo-arterial connections with a left-sided aorta can undergo successful anatomical repair.
We study the motion of a buoyant or a nearly neutrally buoyant nano-sized spheroid in a fluid filled tube without or with an imposed pressure gradient (weak Poiseuille flow). The fluctuating hydrodynamics approach and the deterministic method are both employed. We ensure that the fluctuation–dissipation relation and the principle of thermal equipartition of energy are both satisfied. The major focus is on the effect of the confining boundary. Results for the velocity and the angular velocity autocorrelations (VACF and AVACF), the diffusivities and the drag and the lift forces as functions of the shape, the aspect ratio, the inclination angle and the proximity to the wall are presented. For the parameters considered, the boundary modifies the VACF and AVACF such that three distinct regimes are discernible – an initial exponential decay followed by an algebraic decay culminating in a second exponential decay. The first is due to the thermal noise, the algebraic regime is due both to the thermal noise and the hydrodynamic correlations, while the second exponential decay shows the effect of momentum reflection from the confining wall. Our predictions display excellent comparison with published results for the algebraic regime (the only regime for which earlier results exist). We also discuss the role of the off-diagonal elements of the mobility and the diffusivity tensors that enable the quantifications of the degree of lift and margination of the nanocarrier. Our study covers a range of parameters that are of wide applicability in nanotechnology, microrheology and in targeted drug delivery.
This article presents a laboratory module developed for undergraduate micro/nano engineering laboratory courses in the mechanical engineering departments at the Massachusetts Institute of Technology and King Fahd University of Petroleum and Minerals. In this laboratory, students fabricate superoleophobic membranes by spray-coating of titania nanoparticles on steel meshes, characterize the surfaces and ability of the membrane to retain oil, and then use these membranes to separate an oil-water mixture. The laboratory module covers nanomaterials, nanomanufacturing, materials characterization, and understanding of the concepts of surface tension and hydrostatics, with oil-water separation as an application. The laboratory experiments are easy to set up based on commercially available tools and materials, which will facilitate implementation of this module in other educational institutions. The significance of oil-water separation in the petroleum industry and integration of concepts from fluid mechanics in the laboratory module will help to illustrate the relevance of nanotechnology to mechanical and materials engineering and its potential to address some of the future societal needs.
Our understanding of the politics of race, indigeneity, and ethnicity is informed not only by the work of scholars, but also by the work of leaders and practitioners. The Journal of Race, Ethnicity, and Politics (JREP) is proud to continue our Q&A series with Erik Stegman, executive director of Center for Native American Youth (CNAY) at the Aspen Institute. Our hope is that forums like these will help advance our collective scholarship by better informing our research agendas, validating some of our claims, and building more bridges between the worlds of research, politics, and policy.
Bats are known to be reservoirs of several medically important viruses including lyssaviruses. However, no systematic surveillance for bat rabies has been carried out in India, a canine rabies endemic country with a high burden of human rabies. Surveillance for rabies virus (RABV) infection in bats was therefore carried out in Nagaland, a north-eastern state in India at sites with intense human–bat interfaces during traditional bat harvests. Brain tissues and sera from bats were tested for evidence of infection due to RABV. Brain tissues were subjected to the fluorescent antibody test for detection of viral antigen and real-time reverse transcriptase PCR for presence of viral RNA. Bat sera were tested for the presence of rabies neutralizing antibodies by the rapid fluorescent focus inhibition test. None of the bat brains tested (n = 164) were positive for viral antigen or viral RNA. However, rabies neutralizing antibodies were detected in 4/78 (5·1%) bat sera tested, suggesting prior exposure to RABV or related lyssaviruses. The serological evidence of lyssaviral infection in Indian bats may have important implications in disease transmission and rabies control measures, and warrant extensive bat surveillance to better define the prevalence of lyssaviral infection in bats.
Micro-scale energy storage devices are of great importance to the advancement of low maintenance, high power electronics. They can easily be used in applications that extract energy from mechanical, solar, thermal and thermoelectric sources. Several of these devices have achieved mean areal capacitance of 1.5 mF cm-2 and maximal energy and power densities of 6.6 mJ cm-2 and 44.9 mW cm-2, respectively. It has been demonstrated that a smaller interspace enhances the performance. Currently, these types of devices are only made possible by using several micro-fabrication steps and techniques that are cost prohibitive and limit the larger scale manufacturability. We present a simple but highly scalable and cost effective method in fabricating high power interdigitated micro energy storage devices using binder-free carbon nanotubes membranes and laser irradiation to obtain interspaces on the order of 75 μm. The binder-free electrode devices show higher power density and an improved frequency response, compared to what has been reported in the literature. Additionally, we observed significant reduction in cell resistance leading to enhancement in cell capacitance, and consequently, an increase in energy density.
Deciphering the relative importance of genetic and environmental factors, which play a major role in the prevalence of early childhood caries (ECC), can help clinicians with planning a long-term preventive treatment. The objective of the study was to determine the prevalence and heritability of ECC among monozygotic (MZ) and dizygotic (DZ) twins in Chennai, India, in the year 2013. A cross-sectional study was designed to estimate the prevalence of ECC among twins. Zygosity classification for the survey framework was adapted from a highly accurate parental report questionnaire pertaining to the physical similarity between twins. The associated heritability index was estimated. The Decayed, Missing, Filled Surface (DMFS) Index was used as the diagnostic criterion for dental caries. The prevalence of ECC was estimated at 18.7%. The correlation coefficient between the twin pair showed significant correlation. The heritability index for ECC was estimated at 15% higher prevalence of ECC found among children in the age group 25–36 months. The heritability estimate indicated a relatively low genetic influence for early childhood caries among twins. There was no significant difference detected in the concordance rate for the MZ and DZ twins. Further research could be directed toward the prevalence of ECC among higher age group children to explore the role of genetic and environmental factors.