Evolution and ecology of feeding in elasmobranchs

Paleozoic chondrichthyans had a large gape, numerous spike-liketeeth, limited cranial kinesis, and a non-suspensory hyoid,suggesting a feeding mechanism dominated by bite and ram. Modernsharks are characterized by a mobile upper jaw braced by a suspensoryhyoid arch that is highly kinetic. In batoids, the upper jawis dissociated from the cranium permitting extensive protrusionof the jaws. Similar to actinopterygians, the evolution of highlymobile mandibular and hyoid elements has been correlated withextensive radiation of feeding modes in elasmobranchs, particularlythat of suction. Modern elasmobranchs possess a remarkable varietyof feeding modes for a group containing so few species. Biting,suction or filter-feeding may be used in conjunction with ramto capture prey, with most species able to use a combinationof behaviors during a strike. Suction-feeding has repeatedlyarisen within all recent major elasmobranch clades and is associatedwith a suite of morphological and behavioral specializations.Prey capture in a diverse assemblage of purported suction-feedingelasmobranchs is investigated in this study. Drop in water pressuremeasured in the mouth and at the location of the prey showsthat suction inflow drops off rapidly with distance from thepredator's mouth. Elasmobranchs specializing in suction-feedingmay be limited to bottom associated prey and because of theirsmall gape may have a diet restricted to relatively small prey.Behavior can affect performance and overcome constraints imposedby the fluid medium. Suction performance can be enhanced byproximity to a substrate or by decreasing distance from predatorto prey using various morphological and/or behavioral characteristics.Benthic suction-feeders benefit by the increased strike radiusdue to deflection of water flow when feeding close to a substrate,and perhaps require less accuracy when capturing prey. Suctionand ram-suction-feeding elasmobranchs can also use suction inflowto draw prey to them from a short distance, while ram-feedingsharks must accelerate and overtake the prey. The relationshipbetween feeding strategy and ecology may depend in part on ecological,mechanistic or evolutionary specialization. Mechanistic suction-feedingspecialist elasmobranchs are primarily benthic, while most epibenthicand pelagic elasmobranchs are generalists and use ram, suction,and biting to catch a diversity of prey in various habitats.Some shark species are considered to be ecological specialistsin choosing certain kinds of prey over others. Batoids are evolutionaryspecialists in having a flattened morphology and most are generalistfeeders. Filter-feeding elasmobranchs are ecological, mechanistic,and evolutionary specialists.     

In situ proteolysis for protein crystallization and structure determination

We tested the general applicability of in situ proteolysis to form protein crystals suitable for structure determination by adding a protease (chymotrypsin or trypsin) digestion step to crystallization trials of 55 bacterial and 14 human proteins that had proven recalcitrant to our best efforts at crystallization or structure determination. This is a work in progress; so far we determined structures of 9 bacterial proteins and the human aminoimidazole ribonucleotide synthetase (AIRS) domain.     

Short-term variability of airway caliber-a marker of asthma?

Variability in airway caliber is a characteristic feature of asthma. Previous studies reported that the variability in respiratory system impedance (Zrs), measured by the forced oscillation technique during several minutes of tidal breathing, is increased in asthma and may be a marker of inherent instability of the airways. The aims of this study were to determine if short-term variability in impedance correlates with peak expiratory flow (PEF) variability or airway hyperresponsiveness (AHR). The SD of log-transformed impedance (lnZrsSD) was measured as a marker of short-term variability and compared with the diurnal variability of PEF over 2 wk in 28 asthmatic and 7 nonasthmatic subjects and with AHR to histamine in a cohort of 17 asthmatic and 82 nonasthmatic subjects. In addition, lnZrsSD was measured in eight nonasthmatic subjects before and after methacholine challenge in the upright and supine positions. There were no significant differences in lnZrsSD between asthmatic and nonasthmatic subjects (P = 0.68). Furthermore, in asthmatic subjects, lnZrsSD did not correlate with diurnal variability of PEF (rs = -0.12 P = 0.54) or with AHR to histamine (r = 0.10, P = 0.71). Neither methacholine challenge nor supine posture caused any significant change in lnZrsSD. We conclude that our findings do not support previous reports about the utility of short-term variability of impedance. Our findings suggest that, using standard methods for forced oscillometry, impedance variability does not provide clinically useful information about the severity of asthma.     

Advancing the use of morphometric data for estimating and managing common bottlenose dolphin (Tursiops truncatus) mass

Knowledge of a dolphin's body mass is central to establishing body condition, comparing across individuals, and designing successful management programs. In the present study, sex‐specific prediction equations for estimating body mass were generated from morphometrics (i.e., length and girth) and ages of bottlenose dolphins residing under professionally managed care. Measurements of wild dolphins in Sarasota Bay, Florida, were used to generate sex‐specific body mass reference ranges. Gompertz growth models were fitted to length measurements and age to compare growth across populations. From the regression analyses, the body mass of managed females (R² = 0.937), managed males (R² = 0.953), wild females (R² = 0.979), and wild males (R² = 0.972) were predicted with high levels of accuracy. Managed adults had similar or longer asymptotic lengths compared to their wild conspecifics. To apply this information, ZooMorphTrak, a mobile software application, was developed to provide a new resource for management. The “Approximate” feature was designed to approximate body mass based on user inputs of individual morphometrics. The “Management” feature compared a managed dolphin's known body mass with respect to body mass reference ranges generated from wild dolphins. ZooMorphTrak, developed by the Chicago Zoological Society, is available for download at http://itunes.apple.com .     

First Nations status and emergency department triage scores in Alberta: a retrospective cohort study

Background:Previous studies have found that race is associated with emergency department triage scores, raising concerns about potential health care inequity. As part of a project on quality of care for First Nations people in Alberta, we sought to understand the relation between First Nations status and triage scores.Methods:We conducted a population-based retrospective cohort study of health administrative data from April 2012 to March 2017 to evaluate acuity of triage scores, categorized as a binary outcome of higher or lower acuity score. We developed multivariable multilevel logistic mixed-effects regression models using the levels of emergency department visit, patient (for patients with multiple visits) and facility. We further evaluated the triage of visits related to 5 disease categories and 5 specific diagnoses to better compare triage outcomes of First Nations and non–First Nations patients.Results:First Nations status was associated with lower odds of receiving higher acuity triage scores (odds ratio [OR] 0.93, 95% confidence interval [CI] 0.92–0.94) compared with non–First Nations patients in adjusted models. First Nations patients had lower odds of acute triage for all 5 disease categories and for 3 of 5 diagnoses, including long bone fractures (OR 0.82, 95% CI 0.76–0.88), acute upper respiratory infection (OR 0.90, 95% CI 0.84–0.98) and anxiety disorder (OR 0.67, 95% CI 0.60–0.74).Interpretation:First Nations status was associated with lower odds of higher acuity triage scores across a number of conditions and diagnoses. This may reflect systemic racism, stereotyping and potentially other factors that affected triage assessments.

Health outcomes are markedly worse for First Nations than non–First Nations people. Although this is largely because of inequities in the social determinants of health,^1–4 inequities in the provision of health care also exist.^5,6 Emergency departments serve as a point of accessible health care. Status First Nations patients make up 4.8% of unique patients and 9.4% of emergency visits in Alberta,⁷ and Canadian studies describe First Nations patients’ experiences with racism when seeking emergency care.^8,9Evaluating triage contributes empirically to understanding the health care of First Nations patients insofar as triage is a quantifiable, intermediate process by which systemic racism¹⁰ may influence patient outcomes. The Canadian Triage Acuity Scale¹¹ is a 5-level scale used to classify the severity of patient symptoms. Triage nurses use a brief assessment, medical history, and presenting signs and symptoms to assign each patient a triage score that determines the priority in which the patient should be seen by a provider. Therefore, accurate triage is important for patient health outcomes.¹² In practice, triage is a social interaction where local practice, biases, stereotypes and communication barriers come into play. Studies have found that women receive less acute triage scores than men,^13,14 and that racial minority^13,15–17 and Indigenous^18–20 patients receive less acute triage scores than white or non-Indigenous patients. Indeed, Indigenous patients in Canada have described a perception “of social triaging in the [emergency department], whereby decisions about who is seen first seemed to them [to be] based less on triaged clinical priorities but on the social positioning of the patient.”²¹ Differential triage scores for minority populations raise health equity concerns.As part of a larger mixed-methods project evaluating the quality of emergency care for First Nations people in Alberta, we sought to evaluate quantitative differences in emergency visit characteristics and outcomes of First Nations and non–First Nations people in Alberta. Specifically, we aimed to estimate the relation between First Nations status and acuity of triage, and to evaluate whether predictors of acuity differ by First Nations status.     

Uptake of infant and preschool immunisations in Scotland and England during the COVID-19 pandemic: An observational study of routinely collected data

BackgroundIn 2020, the SARS-CoV-2 (COVID-19) pandemic and lockdown control measures threatened to disrupt routine childhood immunisation programmes with early reports suggesting uptake would fall. In response, public health bodies in Scotland and England collected national data for childhood immunisations on a weekly or monthly basis to allow for rapid analysis of trends. The aim of this study was to use these data to assess the impact of different phases of the pandemic on infant and preschool immunisation uptake rates.Methods and findingsWe conducted an observational study using routinely collected data for the year prior to the pandemic (2019) and immediately before (22 January to March 2020), during (23 March to 26 July), and after (27 July to 4 October) the first UK “lockdown”. Data were obtained for Scotland from the Public Health Scotland “COVID19 wider impacts on the health care system” dashboard and for England from ImmForm.Five vaccinations delivered at different ages were evaluated; 3 doses of “6-in-1” diphtheria, tetanus, pertussis, polio, Haemophilus influenzae type b, and hepatitis B vaccine (DTaP/IPV/Hib/HepB) and 2 doses of measles, mumps, and rubella (MMR) vaccine. This represented 439,754 invitations to be vaccinated in Scotland and 4.1 million for England. Uptake during the 2020 periods was compared to the previous year (2019) using binary logistic regression analysis. For Scotland, uptake within 4 weeks of a child becoming eligible by age was analysed along with geographical region and indices of deprivation. For Scotland and England, we assessed whether immunisations were up-to-date at approximately 6 months (all doses 6-in-1) and 16 to 18 months (first MMR) of age.We found that uptake within 4 weeks of eligibility in Scotland for all the 5 vaccines was higher during lockdown than in 2019. Differences ranged from 1.3% for first dose 6-in-1 vaccine (95.3 versus 94%, odds ratio [OR] compared to 2019 1.28, 95% confidence intervals [CIs] 1.18 to 1.39) to 14.3% for second MMR dose (66.1 versus 51.8%, OR compared to 2019 1.8, 95% CI 1.74 to 1.87). Significant increases in uptake were seen across all deprivation levels.In England, fewer children due to receive their immunisations during the lockdown period were up to date at 6 months (6-in-1) or 18 months (first dose MMR). The fall in percentage uptake ranged from 0.5% for first 6-in-1 (95.8 versus 96.3%, OR compared to 2019 0.89, 95% CI 0.86– to 0.91) to 2.1% for third 6-in-1 (86.6 versus 88.7%, OR compared to 2019 0.82, 95% CI 0.81 to 0.83).The use of routinely collected data used in this study was a limiting factor as detailed information on potential confounding factors were not available and we were unable to eliminate the possibility of seasonal trends in immunisation uptake.ConclusionsIn this study, we observed that the national lockdown in Scotland was associated with an increase in timely childhood immunisation uptake; however, in England, uptake fell slightly. Reasons for the improved uptake in Scotland may include active measures taken to promote immunisation at local and national levels during this period and should be explored further. Promoting immunisation uptake and addressing potential vaccine hesitancy is particularly important given the ongoing pandemic and COVID-19 vaccination campaigns.

Fiona McQuaid and colleagues assess the uptake of infant and pre-school immunisations in Scotland and England during the COVID-19 pandemic.     

A fault detection service for wide area distributed computations

The potential for faults in distributed computing systems is a significant complicating factor for application developers. While a variety of techniques exist for detecting and correcting faults, the implementation of these techniques in a particular context can be difficult. Hence, we propose a fault detection service designed to be incorporated, in a modular fashion, into distributed computing systems, tools, or applications. This service uses well-known techniques based on unreliable fault detectors to detect and report component failure, while allowing the user to trade off timeliness of reporting against false positive rates. We describe the architecture of this service, report on experimental results that quantify its cost and accuracy, and describe its use in two applications, monitoring the status of system components of the GUSTO computational grid testbed and as part of the NetSolve network-enabled numerical solver. This revised version was published online in July 2006 with corrections to the Cover Date.     

To strengthen consensus, consult the stakeholders

CIOMS has been criticised for not adequately consulting stakeholders about its revised ethical guidelines regarding medical research. Political and logistical issues that arise in democratic processes and open exchange of information probably contributed to this exclusion. What might CIOMS have done to be more inclusive and attain broader consensus on its proposed revisions? Consensus is dynamic, and evolves as a community digests new information and perspectives. Engaging the public (and particularly the stakeholders) in discussion about the revisions would have generated broader consensus. It would have encouraged more stakeholders (i.e. researchers, potential research participants, research institutions, or governments) to buy in. CIOMS needs a process to encourage dialogue and stakeholder input. The CIOMS guidelines themselves promote stakeholder consultation and capacity building, but CIOMS has done relatively little to distribute or promote its own guidelines. CIOMS should do more to promote its revised guidelines, and engage stakeholders in dialogue. This paper explores the bioethics debate about universal and relative values to illustrate the value of consultation and consensus building. It concludes that like research sponsors, CIOMS and similar organisations have an ethical responsibility to facilitate capacity building in less developed areas, and to participate more actively in consensus building.     

Genomewide linkage searches for Mendelian disease loci can be efficiently conducted using high-density SNP genotyping arrays

Genomewide linkage searches aimed at identifying disease susceptibility loci are generally conducted using 300–400 microsatellite markers. Genotyping bi-allelic single nucleotide polymorphisms (SNPs) provides an alternative strategy. The availability of dense SNP maps coupled with recent technological developments in highly paralleled SNP genotyping makes it practical to now consider the use of these markers for whole-genome genetic linkage analyses. Here, we report the findings from three successful genomewide linkage analyses of families segregating autosomal recessively inherited neonatal diabetes, craniosynostosis and dominantly inherited renal dysplasia using the Affymetrix 10K SNP array. A single locus was identified for each disease state, two of which are novel. The performance of the SNP array, both in terms of efficiency and precision, indicates that such platforms will become the dominant technology for performing genomewide linkage searches.