Slamming dynamics of diving and its implications for diving-related injuries

In nature, many animals dive into water at high speeds, e.g., humans dive from cliffs, birds plunge, and aquatic animals porpoise and breach. Diving provides opportunities for animals to find prey and escape from predators and is a source of great excitement for humans. However, diving from high platforms can cause severe injuries to a diver. In this study, we demonstrate how similarity in the morphology of diving fronts unifies the slamming force across diving animals and humans. By measuring a time-averaged impulse that increases linearly with the impact height, we are able to estimate the unsteady hydrodynamic forces that an average human body experiences during the slamming phase of a feet-first, hand-first, or head-first dive. We evaluate whether the unsteady forces put the diver at risk of muscle or bone injuries for a particular diving height. Therefore, this study sheds light on a hydrodynamics-based protocol for safe high diving and an evolutionary driver for animal morphology.

A Point Prevalence Study of the Use of Antibiotics in Six Tertiary Care Hospitals in the Kathmandu Valley, Nepal

Background Point prevalence survey (PPS) on antibiotic use developed by the WHO has already been used in many hospitals globally. Objective To obtain information on antibiotic prescribtion using point prevalence survey methodology in six private hospitals in the Kathmandu valley. Method This descriptive cross-sectional study was completed during 20th July to 28th July 2021 using point prevalence survey methodology. The study was conducted among inpatients admitted at or before 8:00 AM on the day of survey in various wards. Data was presented as frequencies and percentages. Result Maximum number of patients were above 60 years [34 (18.7%)]. Number of male and female participants were equal [91 (50%)]. Only one antibiotic was used in 81 patients (44.5%) followed by two antibiotics in 71 (39%) patients. Duration of prophylactic antibiotic use was one day in 66 (63.7%) patients. Blood, urine, sputum, and wound swabs were the common samples for culture. Cultures were positive for 17 (24.7%) samples. The common organisms isolated were E. Coli, Pseudomonas aeruginosa and Klebsiella pneumoniae. Ceftriaxone was the most used antibiotic. Drug and therapeutics, infection control committee and pharmacovigilance activities were present in 3/6 (50%) study sites. Antimicrobial stewardship was present in 3/6 (50%) and microbiological services was present in all hospitals. Antibiotic formulary and antibiotic guideline were present in 4/6 sites and facilities to audit or review surgical antibiotic prophylaxis choice in 2/6 (33.3%) sites, facility to monitor antibiotic use in 4/6 (66.6%) and cumulative antibiotic susceptibility reports in 2/6 (33.3%) study sites. Conclusion Ceftriaxone was the most used antibiotic. E. Coli, Pseudomonas aeruginosa and Klebsiella pneumonia were the commonly isolated organisms. Not all parameters for infrastructure, policy and practice and monitoring and feedback were present at the study sites. KEY WORDS.

Transgenerational effects of β-glucan on thermal tolerance, growth performance, and immune gene expression of endangered cyprinid Tor putitora progeny

Nutritional programming signifies a process in which broodstock feeding approaches have long-term effects on the subsequent progeny. The present study aimed to elucidate whether supplementing golden mahseer, Tor putitora broodstock diets with β-glucan affects progeny growth performance, survival, thermal tolerance, and non-specific immunity. Initially, the growth performance of progeny produced from brooders fed with different levels of β-glucan was non-significant. However, on the 15th and 35th DPH, the maximum weight was observed in fry obtained from the brooders fed with 0.5% followed by 1.0% β-glucan. Furthermore, on 50th DPH, significantly higher weight was registered in the fry from the 0.5% β-glucan fed group while 1.0% β-glucan group had no transgenerational effect on growth. The condition factor of fry obtained from golden mahseer brooders fed with a 0.5% β-glucan diet was greater than the control and 1.0% β-glucan fed group. On the other hand, we did not find any significant transgenerational influence of β-glucan on the survival of the progeny. The thermal tolerance of fry produced from brooders fed with β-glucan was significantly modulated at both end-points (CT_max and CT_min). Expression of interleukin-1β was significantly up-regulated in fry obtained from β-glucan fed brooders. In contrast, the expression level of tumor necrosis factor-α was significantly higher only in fry produced from 1.0% β-glucan fed brooders. The expression of immunoglobulin light chain and serum amyloid A gene was significantly higher in fry produced from 0.5% β-glucan fed brooders. Overall results suggest that the dietary provisioning of β-glucan in golden mahseer brooders can be a strategy to produce healthy and robust fry in captivity for stock enhancement and conservation programs.

Concurrent changes in thermal tolerance thresholds and cellular heat stress response reveals novel molecular signatures and markers of high temperature acclimation in rainbow trout

The objective of this study was to better understand the molecular mechanisms which regulate acclimatory responses and thermal safety margins of rainbow trout (Oncorhynchus mykiss) at temperatures above physiological optimum. For this, we investigated the time course of changes in critical thermal tolerance thresholds and associated hepatic and renal transcript abundance of molecular markers related to cellular stress response, during high temperature acclimation. The experimental fish were initially acclimated to 17 °C and later exposed to a gradually raised elevated temperature regime (22 °C) for a period of 30 days. CT_max, CT_min and mRNA expression of candidate markers were examined before the thermal challenge (T₀) and over the time-course (days) of high temperature exposure (T₁, T₃, T₇, T₁₅ and T₃₀). With respect to organismal response, CT_max was significantly elevated at T₃, but the degree of gain in heat tolerance was not persistent. Contrarily, we observed a gradual loss in cold tolerance with highest CT_min estimate at T₃₀. Based on the time-course of mRNA expression, the studied markers could be categorized into those which were persistently elevated (hsp70a, hsp70b, hspa5, hsp90a, hsp90b, stip1 and serpinh1 in kidney and hsp90b in liver); those which concurred with changes in CT_min (hspbp1, hsp90b, stip1, gr1, hif1a, hyou1, tnfa and tlr5 in kidney); and those which concurred with changes in CT_max (hsp90a, serpinh1, tlr5 and lmo2 in liver). Apparently, transcriptional changes in kidney and liver reflected CT_min and CT_max trend, respectively. Expression profile of stip1 and tlr5 suggest that they are potential novel markers which could reflect thermal limits in rainbow trout. Hepatic metabolic markers were either initially elevated (alt, glud, g6pase1) or down-regulated at different time-points (ast2, gls1, fas, cpt1b, mtor), linked to gluconeogenesis and metabolic depression, respectively. Whereas, growth-axis markers showed no significant differences. Overall, this time-course analysis has revealed potential associations in organismal and tissue-specific cellular response to high temperature acclimation in a thermally sensitive coldwater ectotherm.

β-glucan modulates non-specific immune gene expression, thermal tolerance and elicits disease resistance in endangered Tor putitora fry challenged with Aeromonas salmonicida

An eight-week feeding trial was performed to assess the effect of different dietary levels (0, 0.5, 1.0, and 1.5%) of β-glucan (sourced from Saccharomyces cerevisiae) on growth, survival, immunological parameters (immune gene expression, lysozyme, and antiprotease), total antioxidant status, thermal tolerance, and disease resistance of Tor putitora fry. Feeding of moderate doses (0.5 and 1.0%) of β-glucan significantly improved survival but not weight gain percentage as compared to that received unsupplemented control and highest dose (1.5%) of glucan. Supplementation of β-glucan in diets differentially influenced the mRNA expression of cytokine and other immune genes. For instance, transcripts of cytokines such as tnf-α and il-1β were significantly upregulated, while ifn-γ and il-10 were unaffected by β-glucan intake. Also, the relative mRNA expression of tlr-5 and hepcidin1 along with lysozyme and antiprotease activities were remained largely unchanged by dietary glucan administration. In contrast, β-glucan induced mRNA expression of defensin1 and c3 while decreased the transcript level of mhc-1. On the other hand, dietary inclusion of β-glucan markedly improved total antioxidant levels and extended the thermal tolerance limits at both the ends, as shown by increased CT_max and lower CT_min than the control group. After feeding β-glucan for eight weeks, the fish were bath challenged with a bacterial pathogen, Aeromonas salmonicida. The challenge study results revealed that β-glucan intake improved most of the studied immune parameters, resulting in lower mortality. Overall, dietary inclusion of β-glucan (0.5-1.0%) was efficient in improving the immune responses, thermal tolerance, and disease resistance of T. putitora fry.

Molecular characterization of non-specific immune genes of endangered golden mahseer (Tor putitora) and their expression during embryonic and larval development

The present study was undertaken to characterize and analyze the expression of non-specific immune genes to get an insight into the early immune status of endangered golden mahseer. In this study, the full-length mRNA sequence of IFNγ, TNFα, C3, and IL10 was 927, 1409, 5125 and 1177 bp with an ORF of 558, 765, 4938, and 540 bp, encoding a putative protein of 185, 254, 1645, and 179 amino acid residues, respectively. The deduced amino acid sequences of these genes shared highly conserved structures with those from other cyprinids. Ontogenic real-time qPCR results indicated that expression of IFNγ and TNFα was lower until the morula stage and increased from blastula stage and found maximum at the organogenesis stage. Expression of the C3 gene was lower until the gastrula stage, followed by a linear increase from organogenesis to the pre-metamorphosis stage. The expression of IL10 was significantly lower during early developmental stages (till gastrula stage) and reached maximum at organogenesis. The level of IL1β was found maximum in unfertilized eggs and remained elevated till the morula stage. TLR4 expression remained lower during the initial developmental stages and reached the maximum at the organogenesis stage. The expression level of defensin1 was substantially low until the organogenesis stage. In comparison, hepcidin1 was found considerably high until the blastula stage and remained significantly lower during later stages of development. Overall, the data generated improves knowledge on the immune status of endangered golden mahseer during embryonic and larval development, which may help develop effective immunomodulatory interventions during nursery rearing of golden mahseer to produce fry with better fitness.

Prognostic significance of polyvascular disease in patients admitted with acute decompensated heart failure: the ARIC Study Community Surveillance

Introduction

The prevalence and outcomes of polyvascular disease (PVD) in patients admitted with acute decompensated heart failure (ADHF) have not been previously reported, nor is it known whether associations differ for heart failure (HF) with reduced vs. preserved ejection fraction (HFrEF vs HFpEF, respectively).

Purpose

To investigate the relationship between atherosclerotic involvement of multiple arterial territories and mortality in patients hospitalized with ADHF.

Methods

The Atherosclerosis Risk in Communities (ARIC) study conducted hospital surveillance of adjudicated heart failure in 4 US areas from 2005–2014, with events verified by physician review. Medical histories were abstracted from the hospital record. PVD was defined by coexisting disease in ≥2 arterial beds, identified by prevalent coronary artery disease, peripheral arterial disease, and cerebrovascular disease. Mortality hazards of PVD vs. no PVD were analyzed separately for HFpEF and HFrEF, with adjustment for age, race, sex, year of admission and geographic region. All analyses were weighted by the inverse of the sampling probability.

Results

Of 24,936 ADHF hospitalizations (52% female, 32% Black, mean age 75 years), 19% had PVD (22% among HFrEF hospitalizations, 17% among HFpEF hospitalizations), Figure 1. There was an increasing trend in 1-year mortality with 0, 1 and ≥2 arterial bed involvement, both for patients with HFrEF (29% to 32% to 38%; P-trend=0.0006) and HFpEF (26% to 32% to 37%; P-trend <0.0001). After adjustments, PVD was associated with a 20% higher hazard of 1-year mortality in patients with HFrEF (HR=1.23; 95% CI: 1.06–1.44) and a 30% higher hazard in patients with HFpEF (HR=1.33; 95% CI: 1.09–1.63), with no significant interaction by HF type (P-interaction = 0.5).

Conclusion

Patients hospitalized with ADHF and coexisting PVD have an increased risk of death, irrespective of HF type. Clinical attention should be directed toward PVD, with secondary prevention strategies enacted to improve the prognosis of this vulnerable population.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): National Institutes of Health Distributions of arterial diseaseTrends in 1-year mortality outcomes

Mediators of the effect of ertugliflozin on a composite kidney outcome in patients with type 2 diabetes and atherosclerotic cardiovascular disease: analyses from VERTIS CV

Introduction

Sodium–glucose cotransporter 2 (SGLT2) inhibitors have been shown to slow the decline of kidney function in outcome trials, but the biological mediator(s) underlying the therapeutic benefit are not well established.

Purpose

We performed a post-hoc analysis exploring potential mediators of the effects of the SGLT2 inhibitor ertugliflozin on the VERTIS CV exploratory kidney composite outcome (sustained 40% decrease from baseline in estimated glomerular filtration rate [eGFR], chronic kidney replacement therapy or kidney death).

Methods

In VERTIS CV, 8246 participants with type 2 diabetes mellitus and established atherosclerotic cardiovascular disease were randomised to placebo, ertugliflozin 5 mg or 15 mg (pooled for analyses, as prospectively planned), and were followed for a mean of 3.5 years. The hazard ratio (HR; 95% confidence interval) for the pre-specified exploratory kidney composite outcome was 0.66 (0.50, 0.88). Cox regression models were used to evaluate covariates that were significantly differentially changed from baseline with ertugliflozin treatment as candidate mediators, with a mediator identified as a covariate when added to an unadjusted model of randomised treatment assignment a) yielded a larger hazard ratio; and b) the mediator retained P<0.05 in the model (eGFR was excluded as a covariate). The percentage of mediation was determined by the proportional increase in the HR between the unadjusted and adjusted models for each post-randomisation period: early (first change from baseline measurement) and average (weighted average of change from baseline from all post-baseline measurements). Each potential mediator was tested individually, so across analyses, mediation % sums to >100%.

Results

Of 22 covariates significantly changed by ertugliflozin, nine were identified as potential mediators (Table). The covariates with a high percentage of mediation were those related to changes in blood erythrocytes (haemoglobin, haematocrit and red blood cell mass), with average changes in haemoglobin having the highest percentage of mediation (61.8%). Serum uric acid was associated with a mediation of 29.4% and 50.0% for the early and average post-randomisation effect periods, respectively. Early changes in glycated haemoglobin had a large mediation (50%), but the average change during the trial was not significant. Average change in serum albumin had a large mediation (29.4%). Average changes in body weight and systolic blood pressure had percentages of mediation of 41.2% and 14.7%, respectively.

Conclusion

Multiple factors may be involved in the reduction of the kidney composite outcome observed with ertugliflozin. In the short-term, changes in glycaemia had a high mediation effect. Over the long-term, changes suggestive of haemoconcentration and/or haematopoiesis (natriuresis-related effects), showed the highest percentage of mediation, followed by changes in serum uric acid and body weight (glucosuria-related effects).

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Sponsored by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA in collaboration with Pfizer Inc., New York, NY, USA

Mediation analyses of the effect of ertugliflozin on hospitalisation for heart failure in patients with type 2 diabetes and atherosclerotic cardiovascular disease from the VERTIS CV trial

Introduction

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce risk of hospitalisation for heart failure (HHF) in outcome trials, but the biological mediators underlying the therapeutic benefit are not well established.

Purpose

To identify potential biological mediators through which ertugliflozin reduces risk of HHF.

Methods

In VERTIS CV, 8246 patients with type 2 diabetes and atherosclerotic cardiovascular disease were randomised to ertugliflozin 5 or 15 mg (observations pooled as prospectively planned) or placebo. Cox regression models were used to evaluate the associations between changes in 26 potential mediators with outcomes. Potential mediators were selected based on proposed mechanisms and/or differential change from baseline with SGLT2 inhibitors. Mediation criteria required 1) significant (P<0.05 for change from baseline) effects of ertugliflozin vs placebo on each potential mediator; and 2) significant (P<0.05) association of change in post-randomisation levels of the potential mediator with risk of HHF when added to an unadjusted model of randomised treatment assignment. Percent mediation was determined by comparing the unadjusted hazard ratio and hazard ratio adjusted for change in the potential mediator of interest. Each covariate was tested individually, such that percent mediation across the analyses summed to >100%. Time-dependent models were used to evaluate associations between early (change from baseline for the first post-baseline measurement) and average (weighted average of change from baseline using all post-baseline measurements) changes in covariates with clinical outcomes.

Results

Over a mean of 3.5 years, the incidence rate of HHF was 0.7 and 1.1 per 100 patient-years with ertugliflozin and placebo, respectively. Among 26 candidate mediators, 9 and 13 met the mediation criteria based on early and average changes, respectively. The 3 covariates with the largest mediating effects of early changes included haematocrit (40%), haemoglobin (27%) and HDL-C (23%) (Table); other significant biomarkers included urine albumin/creatinine ratio, and serum albumin, uric acid, chloride, protein and sodium. The 3 biomarkers with the largest mediating effects in average changes included haemoglobin (63%), albumin (50%) and uric acid (47%) (Table); other significant biomarkers included haematocrit, urine albumin/creatinine ratio, body weight, serum protein and chloride, systolic blood pressure, ALT, BUN, eGFR and heart rate.

Conclusions

In these analyses from the VERTIS CV trial, potential markers of volume status and haemoconcentration and/or haematopoiesis were the strongest mediators of the effect of ertugliflozin on reducing risk of HHF in the early and average change periods. Other potential mediators included uric acid, lipid markers and kidney parameters. These findings provide insights into potential mechanisms through which ertugliflozin, and potentially the SGLT2 inhibitor class, may prevent HHF.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Sponsored by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA, and Pfizer Inc., New York, NY, USA.

Knowledge and Practices of Child Protection among the School Health Nurses of Nepal

Background Child protection is burning issues in developing countries including Nepal. Child protection is one of the key works of the school health nurses. Objective To find out about the existing knowledge and practices of child protection among the school health nurses. Method This descriptive cross-sectional study was conducted among 130 school health nurses working in different schools throughout Nepal. The participants were selected using purposive sampling technique and were invited to participate via various online networks. Self-administered questionnaire was used to collect data. Duration of data collection was 20 December 2020 to 10 February 2021. Descriptive statistics was used to analyze and interpret the data. Result Among the 130 Participants, 88.5% belonged to less than 29 years age group and 67.7% had Proficiency Certificate Level in Nursing education. None of them has received training related to child protection recognition and response and 90.8% had work experience of less than 5 years. Eighty percent and 96.9% participants had knowledge regarding the meaning of child right and child abuse respectively. But 45.4% had knowledge on meaning of child neglect; 53.1% and 72.3% had the knowledge of physical abuse and noncontact sexual abuse respectively. Majority (86.9%) of the participants reported as relatives were the abuser and 63.8% replied as home is the common place for abuse. Similarly, 85.4% had received the information regarding child protection via television radio and newspaper. Only 36.1% has already been involved in child protection. The participants who went to local government (Palika), police and Non-government Organizations for coordination for child right issues were 9(19.1%), 7(14.8%) and 8(17.0%) respectively. Conclusion Most of the school health nurses are young without having experience of childhood abuse and received any child protection training before joining the job. They have good knowledge of child right, physical, sexual abuse except child neglect and existing legal arrangements. There is gap in knowledge and practice.

Pinning-Induced Folding-Unfolding Asymmetry in Adhesive Creases

The compression of soft elastic matter and biological tissue can lead to creasing, an instability where a surface folds sharply into periodic self-contacts. Intriguingly, the unfolding of the surface upon releasing the strain is usually not perfect: small scars remain that serve as nuclei for creases during repeated compressions. Here we present creasing experiments with sticky polymer surfaces, using confocal microscopy, which resolve the contact line region where folding and unfolding occurs. It is found that surface tension induces a second fold, at the edge of the self-contact, which leads to a singular elastic stress and self-similar crease morphologies. However, these profiles exhibit an intrinsic folding-unfolding asymmetry that is caused by contact line pinning, in a way that resembles wetting of liquids on imperfect solids. Contact line pinning is therefore a key element of creasing: it inhibits complete unfolding and gives soft surfaces a folding memory.

Elastic Rayleigh-Plateau instability: dynamical selection of nonlinear states

A slender thread of elastic hydrogel is susceptible to a surface instability that is reminiscent of the classical Rayleigh-Plateau instability of liquid jets. The final, highly nonlinear states that are observed in experiments arise from a competition between capillarity and large elastic deformations. Combining a slender analysis and fully three-dimensional numerical simulations, we present the phase map of all possible morphologies for an unstable neo-Hookean cylinder subjected to capillary forces. Interestingly, for softer cylinders we find the coexistence of two distinct configurations, namely, cylinders-on-a-string and beads-on-a-string. It is shown that for a given set of parameters, the final pattern is selected via a dynamical evolution. To capture this, we compute the dispersion relation and determine the characteristic wavelength of the dynamically selected profiles. The validity of the "slender" results is confirmed via simulations and these results are consistent with experiments on elastic and viscoelastic threads.

Regimes of Soft Lubrication

Elastohydrodynamic lubrication, or simply soft lubrication, refers to the motion of deformable objects near a boundary lubricated by a fluid, and is one of the key physical mechanisms to minimise friction and wear in natural and engineered systems. Hence it is of particular interest to relate the thickness of the lubricant layer to the entrainment (sliding/rolling) velocity, the mechanical loading exerted onto the contacting elements, and properties of the elastic boundary. In this work we provide an overview of the various regimes of soft lubrication for two-dimensional cylinders in lubricated contact with compliant walls. We discuss the limits of small and large entrainment velocity, which is equivalent to large and small elastic deformations, as the cylinder moves near thick or thin elastic layers. The analysis focusses on thin elastic coatings, both compressible and incompressible, for which analytical scaling laws are not yet available in the regime of large deformations. By analysing the elastohydrodynamic boundary layers that appear at the edge of the contact, we establish the missing scaling laws - including prefactors. As such, we offer a rather complete overview of physically relevant limits of soft lubrication.