Elliptic jets, part 2. Dynamics of coherent structures: Pairing

The dynamics of the jet column mode of vortex pairing in the near field of an elliptic jet was investigated. Hot-wire measurements and flow visualization were used to examine the details of the pairing mechanism of nonplanar vortical elliptic structures and its effect on such turbulence measures as coherent velocities, incoherent turbulence intensities, incoherent and coherent Reynolds, stresses, turbulence production, and mass entrainment. It was found that pairing of elliptic vortices in the jet column does not occur uniformly around the entire perimeter, unlike in a circular jet. Merger occurs only in the initial major-axis plane. In the initial minor-axis plane, the trailing vortex rushes through the leading vortex without pairing and then breaks down violently, producing considerably greater entrainment and mixing than in circular or plane jets

Selecting the number and values of the CPWI steering angles and the effect of that on imaging quality

Compounded Plane-Wave Imaging (CPWI) has the ability to provide ultrafast imaging for many applications like colour flow imaging, microbubble imaging and elastography. The compounding operation improves the imaging quality at the expense of reducing the frame rate. Due to the importance of frame rate in ultrafast imaging, selecting the number and value of the compounded angles is a critical step to achieve the best possible imaging quality using the minimum number of angles whilst preserving the frame rate. This paper produces a new method for selecting the angular range and the number of angles in CPWI depending on the characteristics of the transducer and medium using Field II program. Experiments were performed on a wire phantom to show the efficiency of the produced method. The results show a comparative imaging quality of CPWI at the selected parameters when compared with linear imaging

Two-way Quality Assessment Approach for Tumour Detection using Free-hand Strain Imaging

A novel two-way image quality assessment method is proposed for free-hand strain imaging. In elasticity imaging, tissue with different stiffness exhibit varying contrast in the strain images and detectability of a lesion is measured using elastographic contrast-to-noise ratio (CNRe). Representing quality of strain images quantitatively is vital for improving imaging techniques and also for clinical diagnosis. It avoids the subjective approach of interpreting strain images. Conventionally, contrast between stiff lesion and surrounding soft tissue is measured using contrast-to-noise ratio and strain image with the highest CNRe amplitude is considered an optimal strain image. However experimental results have suggested that merely CNRe metric is often misleading and does not always represent the true elastic modulus contrast as the correlation coefficient falls below an acceptable levels and accuracy is compromised. Therefore in this study, the objective is to propose a comprehensive strain image quality assessment method which is reliable for clinical examinations and research

Novelty Induces Behavioural And Glucocorticoid Responses In A Songbird Artificially Selected For Divergent Personalities

Stress physiology is thought to contribute to individual differences in behaviour. In part this reflects the fact that canonical personality measures consist of responses to challenges, including novel objects and environments. Exposure to novelty is typically assumed to induce a moderate increase in glucocorticoids (CORT), although this has rarely been tested. We tested this assumption using great tits, Parus major, selected for divergent personalities (bold-fast and shy-slow explorers), predicting that the shy birds would exhibit higher CORT following exposure to a novel object. We also scored behavioural responses to the novel object, predicting that bold birds would more frequently approach the novel object and exhibit more abnormal repetitive behaviours. We found that the presence of a novel object did induce a moderate CORT response, but selection lines did not differ in the magnitude of this response. Furthermore, although both selection lines showed a robust CORT elevation to a subsequent restraint stressor, the CORT response was stronger in bold birds and this effect was specific to novel object exposure. Shy birds showed a strong positive phenotypic correlation between CORT concentrations following the novel object exposure and the subsequent restraint stress. Behaviourally, the selection lines differed in their response during novel object exposure: as predicted, bold birds more frequently approached the novel object and shy birds more strongly decreased overall locomotion during the novel object trial, but birds from both selection lines showed significant and similar frequencies of abnormal repetitive behaviours during novel object exposure. Our findings support the hypothesis that personality emerges as a result of correlated selection on behaviour and underlying endocrine mechanisms and suggest that the relationship between endocrine stress physiology and personality is context dependent

Improved shear wave-front reconstruction method by aligning imaging beam angles with shear-wave polarization: Applied for shear compounding application

In shear compounding, shear waves are generated at various angles and individual elasticity maps are averaged to reduce noise and improve accuracy. The steered shear waves tilt the tissue motion direction therefore conventional plane wave tracking is not capable of capturing true shear wave amplitude and direction. The proposed method aligns the tracking beams with the shear wave angles, enables beam-axis in the direction of tissue motion to estimate true shear wave motion vector. In this experimental work, shear waves are produced at five different angles and motion is captured using proposed and conventional method. All the experiments are conducted using inclusion-based elasticity phantom. In the results, the displacement maps show that proposed method accurately captured the steered push-beam wave-fronts while conventional method produced push-beam direction artefacts. In the final compounded elasticity maps, the proposed method slightly improved background-to-inclusion elasticity ratio, CNR by 2 dB, and produced inclusion boundary shape sharper than the conventional tracking

Kaempferol Treatment after Traumatic Brain Injury during Early Development Mitigates Brain Parenchymal Microstructure and Neural Functional Connectivity Deterioration at Adolescence.

Targeting mitochondrial ion homeostasis using Kaempferol, a mitochondrial Ca2+ uniporter channel activator, improves energy metabolism and behavior soon after a traumatic brain injury (TBI) in developing rats. Because of broad TBI pathophysiology and brain mitochondrial heterogeneity, Kaempferol-mediated early-stage behavioral and brain metabolic benefits may accrue from diverse sources within the brain. We hypothesized that Kaempferol influences TBI outcome by differentially impacting the neural, vascular, and synaptic/axonal compartments. After TBI at early development (P31), functional magnetic resonance imaging and diffusion tensor imaging (DTI) were applied to determine imaging outcomes at adolescence (2 months post-injury). Vehicle and Kaempferol treatments were made at 1, 24, and 48 h post-TBI, and their effects were assessed at adolescence. A significant increase in neural connectivity was observed after Kaempferol treatment as assessed by the spatial extent and strength of the somatosensory cortical and hippocampal resting-state functional connectivity (RSFC) networks. However, no significant RSFC changes were observed in the thalamus. DTI measures of fractional anisotropy (FA) and apparent diffusion coefficient, representing synaptic/axonal and microstructural integrity, showed significant improvements after Kaempferol treatment, with highest changes in the frontal and parietal cortices and hippocampus. Kaempferol treatment also increased corpus callosal FA, indicating measurable improvement in the interhemispheric structural connectivity. TBI prognosis was significantly altered at adolescence by early Kaempferol treatment, with improved neural connectivity, neurovascular coupling, and parenchymal microstructure in select brain regions. However, Kaempferol failed to improve vasomotive function across the whole brain, as measured by cerebrovascular reactivity. The differential effects of Kaempferol treatment on various brain functional compartments support diverse cellular-level mitochondrial functional outcomes in vivo

The pervasive triad of food security, gender inequity and women\u27s health: Exploratory research from sub-Saharan Africa

Objectives: This study was designed to explore the interactions between food securing activities, health and gender equity from the perspective of rural east African women. The specific objectives were to document the critical interaction among these three issues - food security, gender inequity, women\u27s health within the context of sub-Saharan Africa; to describe the nature of this triad from the perspective of women farmers in Africa; and to propose a framework for linking available interventions to the vicious nature of this triad. Setting: In-depth interviews and focus group discussions were conducted with rural women farmers in Kwale District, Kenya and Bagamoyo District, Tanzania. Methods: A total of 12 in-depth interviews and 4 focus group discussions have been included in this analysis. Transcribed text from interviews and focus group discussions were coded and thematic conceptual matrices were developed to compare dimensions of common themes across interviews and settings. A thematic analysis was then performed and a framework developed to understand the nature of the triad and explore the potential for interventions within the interactions. Findings: The vicious cycle of increasing work, lack of time, and lack of independent decision making for women who are responsible for food production and health of their families, has health and social consequences. Food securing activities have negative health consequences for women, which are further augmented by issues of gender inequity. Conclusion: The African development community must respond by thinking of creative solutions and appropriate interventions for the empowerment of women farmers in the region to ensure their health

Volumetric laser endomicroscopy and its application to Barrett's esophagus: results from a 1,000 patient registry.

Volumetric laser endomicroscopy (VLE) uses optical coherence tomography (OCT) for real-time, microscopic cross-sectional imaging. A US-based multi-center registry was constructed to prospectively collect data on patients undergoing upper endoscopy during which a VLE scan was performed. The objective of this registry was to determine usage patterns of VLE in clinical practice and to estimate quantitative and qualitative performance metrics as they are applied to Barrett's esophagus (BE) management. All procedures utilized the NvisionVLE Imaging System (NinePoint Medical, Bedford, MA) which was used by investigators to identify the tissue types present, along with focal areas of concern. Following the VLE procedure, investigators were asked to answer six key questions regarding how VLE impacted each case. Statistical analyses including neoplasia diagnostic yield improvement using VLE was performed. One thousand patients were enrolled across 18 US trial sites from August 2014 through April 2016. In patients with previously diagnosed or suspected BE (894/1000), investigators used VLE and identified areas of concern not seen on white light endoscopy (WLE) in 59% of the procedures. VLE imaging also guided tissue acquisition and treatment in 71% and 54% of procedures, respectively. VLE as an adjunct modality improved the neoplasia diagnostic yield by 55% beyond the standard of care practice. In patients with no prior history of therapy, and without visual findings from other technologies, VLE-guided tissue acquisition increased neoplasia detection over random biopsies by 700%. Registry investigators reported that VLE improved the BE management process when used as an adjunct tissue acquisition and treatment guidance tool. The ability of VLE to image large segments of the esophagus with microscopic cross-sectional detail may provide additional benefits including higher yield biopsies and more efficient tissue acquisition. Clinicaltrials.gov NCT02215291

Fatal and non-fatal injury outcomes: results from a purposively sampled census of seven rural subdistricts in Bangladesh

Background 90% of the global burden of injuries is borne by low-income and middle-income countries (LMICs). However, details of the injury burden in LMICs are less clear because of the scarcity of data and population-based studies. The Saving of Lives from Drowning project, implemented in rural Bangladesh, did a census on 1·2 million people to fill this gap. This Article describes the epidemiology of fatal and non-fatal injuries from the study. Methods In this study, we used data from the baseline census conducted as part of the Saving of Lives from Drowning (SoLiD) project. The census was implemented in 51 unions from seven purposively sampled rural subdistricts of Bangladesh between June and November, 2013. Sociodemographic, injury mortality, and morbidity information were collected for the whole population in the study area. We analysed the data for descriptive measures of fatal and non-fatal injury outcomes. Age and gender distribution, socioeconomic characteristics, and injury characteristics such as external cause, intent, location, and body part affected were reported for all injury outcomes. Findings The census covered a population of 1 169 593 from 270 387 households and 451 villages. The overall injury mortality rate was 38 deaths per 100 000 population per year, and 104 703 people sustained major non-fatal injuries over a 6-month recall period. Drowning was the leading external cause of injury death for all ages, and falls caused the most number of non-fatal injuries. Fatal injury rates were highest in children aged 1–4 years. Non-fatal injury rates were also highest in children aged 1–4 years and those aged 65 years and older. Males had more fatal and non-fatal injuries than females across all external causes except for burns. Suicide was the leading cause of injury deaths in individuals aged 15–24 years, and more than 50% of the suicides occurred in females. The home environment was the most common location for most injuries. Interpretation The burden of fatal and non-fatal injuries in rural Bangladesh is substantial, accounting for 44 050 deaths and 21 million people suffering major events annually. Targeted approaches addressing drowning in children (especially those aged 1–4 years), falls among the elderly, and suicide among young female adults are urgently needed to reduce injury deaths and morbidity in Bangladesh