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Typhoon Haiyan partially destroyed the Ormoc District Hospital in the Philippines. A field hospital was established to replace its outpatient department for 5 weeks. We investigated the reasons for medical consultation in the field hospital.
We described the consultations by sex, age, week, and diagnosis according to the Surveillance in Post-Extreme Emergencies and Disasters system. We compared the number and proportion of upper respiratory tract infections (URTIs) with a control season in 2014.
We included 6785 consultations, 55.9% from women. The majority of consultations were communicable diseases (88.2%) followed by noncommunicable (7.1%) and injuries (5.6%). Males suffered more often from injuries than women (66.0% vs 34.0%). Consultations due to injuries decreased from 10.0% in the first to 2.9% in the last week. The most frequent diagnosis over the study period was acute respiratory infections (ARIs) (73.1%), of which 83.0% were children. The number of daily URTIs was higher than in a similar 2014 period.
ARI was the most prevalent diagnosis. We recommend ARI treatments being fully accessible after such a disaster. During the first week, injury prevention should focus on adult men. Studies after natural disasters should include control periods to better understand disease distribution, ultimately improving the prioritization in disasters.
Unstable shear layers in environmental and industrial flows roll up into a series of vortices, which often form complex nonlinear merging patterns such as pairs and triplets. These patterns crucially determine the subsequent turbulence, mixing and scalar transport. We show that the late-time, highly nonlinear merging patterns are predictable from the linearized initial state. The initial asymmetry between consecutive wavelengths of the vertical velocity field provides an effective measure of the strength and pattern of vortex merging. The predictions of this measure are substantiated using direct numerical simulations. We also show that this measure has significant implications in determining the route to turbulence and the ensuing turbulence characteristics.
According to the celebrated Bolgiano–Obukhov (Bolgiano, J. Geophys. Res., vol. 64 (12), 1959, pp. 2226–2229; Obukhov, Dokl. Akad. Nauk SSSR, vol. 125, 1959, p. 1246) phenomenology for moderately stably stratified turbulence, the energy spectrum in the inertial range shows a dual scaling: the kinetic energy follows (i)
, and (ii)
is the Bolgiano wavenumber. The
scaling, akin to passive scalar turbulence, is a direct consequence of the assumption that buoyancy is insignificant for
. We revisit this assumption, and using the constancy of kinetic and potential energy fluxes and simple theoretical analysis, we find that the
spectrum is absent. This is because the velocity field at small scales is too weak to establish a constant kinetic energy flux as in passive scalar turbulence. A quantitative condition for the existence of the second regime is also derived in the paper.
Hybrid organic-inorganic semiconducting interfaces have attracted attention in photodiodes and field-effect transistors (FETs) due to the realization of intrinsic p-n junctions and their mechanical flexibility. With the difficulty of developing high-mobility n-type organic semiconductors due to the necessity of low LUMO levels and ambient environment stability, solution processable inorganic materials are an excellent alternative. ZnO is an intrinsic n-type semiconductor which is non-toxic and sol-gel processable, creating avenues for film patterning and fully solution processed devices. We report the improvement of electron mobilities in ZnO FETs through simple UV-Ozone processing which reduces lattice defects within the film and at the SiO2/ZnO interface. Treated ZnO films yield electron mobilities close to 10-2 cm2/Vs and on/off current ratios of 104 while non-treated films have mobilities on the order of 10-5 cm2/Vs and an order of magnitude lower on/off current ratios. Treated films also yield improved photoresponsivity and detectivity in hybrid ZnO-organic photodetectors.
A layer of silver nanoparticles created by thermal annealing of evaporated silver films can increase the photocurrents in silicon-on-insulator (SOI) devices by fivefold or more, but significant enhancements have been restricted to wavelengths greater than 800 nm. Here we report a significant enhancement of photoconductance at shorter wavelengths (500-750 nm) by using a monolayer of silver nanoparticles transferred from a colloidal suspension. Photocurrents on SOI increased in the 500-750 nm spectral range with the addition of silver nanoparticles, with enhancements more than two times; enhancements at longer wavelengths were small, in contrast to results with annealed silver films. We prepared similar colloidal silver nanoparticle monolayers layers on nanocrystalline silicon solar cells with conducting oxide top layers. There is an overall decrease in the quantum efficiency of these cells with the deposition of silver nanoparticles. We attribute these effects to the substantial substrate-mediated changes in the localized surface plasmon resonance frequencies of the differing nanoparticle configurations.
The standard resonance conditions for Bragg scattering as well as weakly nonlinear wave triads have been traditionally derived in the absence of any background velocity. In this paper, we have studied how these resonance conditions get modified when uniform, as well as various piecewise linear velocity profiles, are considered for two-layered shear flows. Background velocity can influence the resonance conditions in two ways: (i) by causing Doppler shifts, and (ii) by changing the intrinsic frequencies of the waves. For Bragg resonance, even a uniform velocity field changes the resonance condition. Velocity shear strongly influences the resonance conditions since, in addition to changing the intrinsic frequencies, it can cause unequal Doppler shifts between the surface, pycnocline and the bottom. Using multiple scale analysis and Fredholm alternative, we analytically obtain the equations governing both the Bragg resonance and the wave triads. We have also extended the higher-order spectral method, a highly efficient computational tool usually used to study triad and Bragg resonance problems, to incorporate the effect of piecewise linear velocity profile. A significant aspect, both on the theoretical and numerical fronts, has been extending the potential flow approximation, which is the basis of the study of these kinds of problems, to incorporate piecewise constant background shear.
Eggshell Membrane (ESM) is a naturally occurring proteinaceous microfibrous scaffold capable of mimicking the extracellular matrix (ECM). The extraction methodology deployed for its extraction process impedes its extensive application as a biomaterial in regenerative medicine. Herein, a unique route was deployed to decorate the surface of ESM with electrospun polycaprolactone (PCL) nanofiber in order to ameliorate the above problems and also fabricate a novel ECM mimicking bilayered scaffold for skin tissue engineering applications. Microstructural and surface topographic analysis confirms the formation of bilayered structure with smooth electrospun PCL nanofibers decorated on ESM. Carbodiimide chemistry was utilized to crosslink the two layers. Cytocompatibility evaluation of scaffolds was carried out with Human dermal fibroblast (HDF) cells. The biomimetic architecture and protein rich composition of as fabricated bilayered construct facilitated extensive cell adhesion, proliferation and migration in contrast the bare natural tissue led to impeded cell adhesion.
Computer-assisted navigation (CAN) improves the accuracy of spinal instrumentation in vertebral fractures and degenerative spine disease; however, it is not widely adopted because of lack of training, high capital costs, workflow hindrances, and accuracy concerns. We characterize shifts in the use of spinal CAN over time and across disciplines in a single-payer health system, and assess the impact of intra-operative CAN on trainee proficiency across Canada.
A prospectively maintained Ontario database of patients undergoing spinal instrumentation from 2005 to 2014 was reviewed retrospectively. Data were collected on treated pathology, spine region, surgical approach, institution type, and surgeon specialty. Trainee proficiency with CAN was assessed using an electronic questionnaire distributed across 15 Canadian orthopedic surgical and neurosurgical programs.
In our provincial cohort, 16.8% of instrumented fusions were CAN-guided. Navigation was used more frequently in academic institutions (15.9% vs. 12.3%, p<0.001) and by neurosurgeons than orthopedic surgeons (21.0% vs. 12.4%, p<0.001). Of residents and fellows 34.1% were fully comfortable using spinal CAN, greater for neurosurgical than orthopedic surgical trainees (48.1% vs. 11.8%, p=0.008). The use of CAN increased self-reported proficiency in thoracic instrumentation for all trainees by 11.0% (p=0.036), and in atlantoaxial instrumentation for orthopedic trainees by 18.0% (p=0.014).
Spinal CAN is used most frequently by neurosurgeons and in academic centers. Most spine surgical trainees are not fully comfortable with the use of CAN, but report an increase in technical comfort with CAN guidance particularly for thoracic instrumentation. Increased education in spinal CAN for trainees, particularly at the fellowship stage and, specifically, for orthopedic surgery, may improve adoption.
Background: External ventricular drain (EVD) insertion is a common neurosurgical procedure performed in patients with life-threatening conditions, but can be associated with complications. The objectives of this study are to evaluate data on national practice patterns and complications rates in order to optimize clinical care Methods: The Canadian Neurosurgery Research Collaborative conducted a prospective multi-centre registry of patients undergoing EVD insertions at Canadian residency programs Results: In this interim analysis, 4 sites had recruited 46 patients (mean age: 53.9 years, male:female 2:1). Most EVD insertions occurred outside of the operating theatre, using free-hand technique, and performed by junior neurosurgery residents (R1-R3). The catheter tip was in the ipsilateral frontal horn or body of the lateral ventricle in 76% of cases. Suboptimally placed catheters did not have higher rates of short-term occlusion. EVD-related hemorrhage occurred in 6.5% (3/45) with only 1 symptomatic patient. EVD-related infection occurred in 13% (6/46) at a mean of 6 days and was associated with longer duration of CSF drainage (P=0.039; OR: 1.13) Conclusions: Interim results indicate rates of EVD-related complications may be higher than previously thought. This study will continue to recruit patients to confirm these findings and determine specific risk factors associated with them
Dental pulp stem cells (DPSCs) can differentiate into bone cells when provided the correct environment, potentially generating cells to repair non-union fractures. Polylactic Acid (PLA) is a biocompatible polymer for 3-D printing of scaffolds, but DPSCs do not proliferate well on PLA. With the goal of making PLA more conducive for DPSC growth, Graphene Oxide (GO); partially reduced Graphene Oxide (pRGO); GO with iron nanoparticles (FeGO) or Fe-pRGO were incorporated into PLA and spun cast as thin films onto silicon wafers for DPSC plating. DPSCs on Fe-pRGO displayed the fastest doubling time and the highest cell modulus; Fe-pRGO with exterior magnets produced high cell density. SEM demonstrated DPSC mineralization, whereas PLA-only DPSC cultures showed none. Results suggest that PLA/Fe-pRGO and PLA/pRGO enhance DPSC proliferation and possibly differentiation with the potential for use as a 3-D printed scaffold for tissue engineering.
In this paper, we have considered the effects of the shallowness of the domain as well as the air–water free surface on the stratified shear instabilities of the fluid underneath. First, we numerically solve the non-Boussinesq Taylor–Goldstein equation for smooth velocity and density profiles of a model shear layer with a free surface. When the depth of the fluid is relatively shallow compared to the shear layer thickness, the surface gravity waves existing at the free surface come closer to the waves existing in the shear layer. This can lead to resonant wave interactions, making the flow unstable to more varieties of modal instabilities. In order to obtain a deeper understanding of the instability mechanisms, we have performed analytical studies with broken-line profiles (profiles for which vorticity and density are piecewise constant). Furthermore, reduced-order broken-line profiles have also been developed, based on which dispersion diagrams are constructed. Through these diagrams we have underpinned the resonantly interacting waves leading to each type of instability. Two new instabilities have been found; one of them, referred to as the ‘surface gravity – interfacial gravity (SG-IG) mode’, arises due to the interaction between a surface gravity wave and an interfacial gravity wave, and would therefore be absent if there is no internal density stratification. The other one – the ‘surface gravity – lower vorticity (SG-LV) mode’, which arises due to the interaction between a surface gravity wave and the lower vorticity wave, surpasses Kelvin–Helmholtz (KH) instability to become the most unstable mode, provided the system is significantly shallow. Stability boundary of the SG-LV mode is found to be quite different from that of KH. In fact, KH becomes negligible for relatively shallow flows, while SG-LV’s growth rate is significant – comparable to the growth rate of KH for unbounded domains (
). Moreover, the SG-LV mode is found to be analogous to the barotropic mode observed in two-layer quiescent flows. We have found that the effect of a free surface on the Holmboe instability is not appreciable. Holmboe in the presence of a free surface is found to be analogous to the baroclinic mode observed in two-layer quiescent flows. Except for the Holmboe instability, remarkable differences are observed in all other instabilities occurring in shallow domains when the air–water interface is replaced by a rigid lid. We infer that the rigid-lid approximation is valid for large vertical domains and should be applied with caution otherwise. Furthermore, we have also shown that if shear is absent at the free surface, our problem can be modelled using Boussinesq approximation, that is,
density variations in the inertial terms can still be neglected.
Background: Neurosurgical residents face a unique combination of challenges, including long duty hours, technically challenging cases, and uncertain employment prospects. We sought to assess the demographics, interests, career goals, self-rated happiness, and overall well-being of Canadian neurosurgery residents. Methods: A cross-sectional survey was developed and sent through the Canadian Neurosurgery Research Collaborative to every resident enrolled in a Canadian neurosurgery program as of April 1, 2016. Results: We analyzed 76 completed surveys of 146 eligible residents (52% response rate). The median age was 29 years, with 76% of respondents being males. The most popular subspecialties of interest for fellowship were spine, oncology, and open vascular neurosurgery. The most frequent self-reported number of worked hours per week was the 80- to 89-hour range. The majority of respondents reported a high level of happiness as well as stress. Sense of accomplishment and fatigue were reported as average to high and overall quality of life was low for 19%, average for 49%, and high for 32%. Satisfaction with work-life balance was average for 44% of respondents and was the only tested domain in which significant dissatisfaction was identified (18%). Overall, respondents were highly satisfied with their choice of specialty, choice of program, surgical exposure, and work environment; however, intimidation was reported in 36% of respondents and depression by 17%. Conclusions: Despite a challenging residency and high workload, the majority of Canadian neurosurgery residents are happy and satisfied with their choice of specialty and program. However, work-life balance, employability, resident intimidation, and depression were identified as areas of active concern.
In this paper we express the linearized dynamics of interacting interfacial waves in stratified shear flows in the compact form of action-angle Hamilton’s equations. The pseudo-energy serves as the Hamiltonian of the system, the action coordinates are the contribution of the interfacial waves to the wave action and the angles are the phases of the interfacial waves. The term ‘generalized action angle’ aims to emphasize that the action of each wave is generally time dependent and this allows for instability. An attempt is made to relate this formalism to the action at a distance resonance instability mechanism between counter-propagating vorticity waves via the global conservations of pseudo-energy and pseudo-momentum.
This chapter is about how panchayats, institutions of rural local government in India, cope with conflicting organisational requirements. These requirements arise from the need to harmonise the organisation's internal processes with constraints imposed by the other organisations involved in rural development projects and the electoral necessity of satisfying popular aspirations. Using ethnographic methods like participant observations and unstructured interviews we analyse implementation of the Mahatma Gandhi National Rural Employment Guarantee Act (MGNREGA) in three districts of the eastern Indian state of West Bengal. Our study reveals that conflicting organisational requirements and stakeholder interests necessitate deviations from prescribed procedures. In such a situation a panchayat's success depends on its ability to camouflage deviations by formulation and enforcement of informal rules with the active support of different stakeholders. The present three-tier panchayats in West Bengal came into existence in 1978.
During its prolonged and uninterrupted existence, it has been entrusted with the responsibility of providing all services required by the rural citizens (Robinson, 2005). This not only makes it an important institution for rural citizens but also imparts considerable political importance to it. It is acknowledged that winning the panchayat elections is the first step towards forming a government at the state level (Chakrabarti, 2016). While a panchayat's political importance makes it prone to perils of partisan politics (Kundu, 2009), inadequate fiscal decentralisation makes it dependent on external funding agencies (Robinson, 2005). Thus, panchayats not only have to deal with their internal processes formulated by the Panchayati Raj Department, but have to abide by funding agencies’ guidelines. Moreover, the presence of different political combinations at different tiers of panchayat and dynamics of politician-bureaucracy relationship make partisan politics integral to their functioning.
The MGNREGA, with a dual focus on providing guaranteed employment and creating rural assets, is the flagship rural development initiative of the Indian government. While the financial liability of the MGNREGA is shared by the union and state governments in 75:25 ratio, panchayats are responsible for identifying works, framing projects, selecting beneficiaries, executing projects and paying wages. However, panchayats have to perform the above functions after complying with the guidelines issued by the union and state governments (MoRD, 2008). The MGNREGA's relationship with rural livelihood also makes it a politically important programme.
Background: The Canadian Neurosurgery Research Collaborative (CNRC) was founded in November 2015 as a resident-led national network for multicentre research. We present an annual report of our activities. Methods: CNRC meetings and publications were reviewed and summarized. The status of ongoing and future studies was collected from project leaders. Results: In its first year, the CNRC produced two papers accepted for publication in the Canadian Journal of Neurological Sciences: A CNRC launch letter and a study of operative volume at Canadian neurosurgery residency programs. Three manuscripts are in preparation: 1) a study of the demographics of Canadian neurosurgery residents, 2) an assessment of mobile devices usage patterns and 3) a validation study of the most utilized neurosurgery mobile apps. In addition, protocols for two multi-centre studies are currently undergoing national Research Ethics Board review: A retrospective study of the incidence and predictors of cerebellar mutism and a prospective registry of external ventricular drain procedures and complications. The network is now a registered not-for-profit organization endorsed by the Canadian Neurosurgical Society. Conclusions: The CNRC is a feasibile, relevant and productive resident-led national research network. As the CNRC matures, we look forward to expanding the scope and impact of its projects.
Background: Web 2.0 technologies (e.g. blogs, social networks, and wikis) are increasingly being utilized by medical schools and postgraduate training programs as tools for information dissemination. These technologies offer the unique opportunity to track metrics of user engagement and interaction. Here, we employ Web 2.0 technologies to assess academic behaviors among neurosurgery residents. Methods: We performed a retrospective review of all educational lectures, part of the core Neurosurgery Residency curriculum at the University of Toronto, posted on our teaching blog (www.TheBrainSchool.net) from Sept 2013 - Nov 2016. We looked for associations with lecturer’s academic position, timing of examinations, and lecture/subspecialty topic. Results: The overall number of clicks on 123 lectures was 1079. Most of these clicks were occurring during the in-training exam month (43%). Click numbers were significantly higher on lectures presented by faculty (mean 18.6, SD ± 4.1) compared to residents-delivered lectures (mean 8.4, SD ± 2.1) (P= 0.031). Functional neurosurgery lectures were the most downloaded (47%), followed by pediatric neurosurgery (22%). Conclusions: The current study demonstrates the value of Web 2.0 analytic tools in examining residents study behavior. Residents tend to ‘cram’ downloading lectures in the same month of training exams and display a preference for faculty-delivered lectures.
Background: No standardized method of resident operative-case logging exists. Our study sought to develop a standardized form used by residents to log operative-cases. Methods: Members of the Canadian Neurosurgery Research Collaborative (CNRC), a national resident-led research organization have created a standardized document based on the current Royal College objectives for operative procedures (section 5). Modifications to structure and content will be guided via consensus from Canadian neurosurgery program-directors. Results: Program directors in each CNRC collaborative institution will be asked to modify the standardized form. The CNRC currently involves thirteen of the fourteen Canadian neurosurgery residency programs. Additional consensus, if necessary, can be reached at the Royal College meeting for program directors of neurosurgery March 20th 2017. Conclusions: A standardized operative-case log represents the first step in a prospective study towards compiling operative volume of all Canadian neurosurgical residents over one academic year. Such data will be essential to guide informed decisions with regard to Royal College requirements as Canadian neurosurgical programs transition to a competency based framework.
Background: Communicating with senior neurosurgical colleagues during residency necessitates a reliable and versatile smartphone. Smartphones and their apps are commonplace. They enhance communication with colleagues, provide the ability to access patient information and results, and allow access to medical reference applications. Patient data safety and compliance with the Personal Health Information Protection Act (PHIPA, 2004) in Canada remain a public concern that can significantly impact the way in which mobile smartphones are utilized by resident physicians Methods: Through the Canadian Neurosurgery Research Collaborative (CNRC), an online survey characterizing smartphone ownership and utilization of apps among Canadian neurosurgery residents and fellows was completed in April 2016. Results: Our study had a 47% response rate (80 surveys completed out of 171 eligible residents and fellows). Smartphone ownership was almost universal with a high rate of app utilization for learning and facilitating the care of patients. Utilization of smartphones to communicate and transfer urgent imaging with senior colleagues was common. Conclusions: Smartphone and app utilization is an essential part of neurosurgery resident workflow. In this study we characterize the smartphone and app usage within a specialized cohort of residents and suggest potential solutions to facilitate greater PHIPA adherence
Background: Computer-assisted navigation (CAN) may guide spinal instrumentation, and requires alignment of patient anatomy to imaging. Iterative-Closest-Point algorithms register anatomical and imaging datasets, which may fail in the presence of significant geometric congruence leading to inaccurate navigation. We computationally quantify geometric congruence in posterior spinal exposures, and identify predictors of potential navigation inaccuracy. Methods: Midline posterior exposures were performed from C1-S1 in four human cadavers. An optically-based CAN generated surface maps of the posterior elements at each level. Maps were reconstructed to include bilateral hemilamina, or unilateral hemilamina with/without the base of the spinous process. Maps were fitted to symmetrical geometries (cylindrical/spherical/planar) using computational modelling, and the degree of model fit quantified. Results: Increased cylindrical/spherical/planar symmetry was seen in the subaxial cervical spine relative to the high-cervical and thoracolumbar spine (p<0.001). Inclusion of the base of the spinous process decreased symmetry independent of spinal level (p<0.001). Registration with bilateral vs. unilateral hemilamina did not significantly reduce geometric symmetry. Conclusions: Geometric congruence is most evident at C1 and the subaxial cervical spine, warranting greater vigilance in navigation accuracy verification. At all levels, inclusion of the base of the spinous process in unilateral registration decreases the likelihood of geometric symmetry and navigation error.