Sex ratio distorting microbes exacerbate arthropod extinction risk in variable environments

Maternally-inherited sex ratio distorting microbes (SRDMs) are common among arthropod species. Typically, these microbes cause female-biased sex ratios in host broods, either by; killing male offspring, feminising male offspring, or inducing parthenogenesis. As a result, infected populations can experience drastic ecological and evolutionary change. The mechanism by which SRDMs operate is likely to alter their impact on host evolutionary ecology; despite this, the current literature is heavily biased towards a single mechanism of sex ratio distortion, male-killing. Furthermore, amidst the growing concerns surrounding the loss of arthropod diversity, research into the impact of SRDMs on the viability of arthropod populations is generally lacking. In this study, using a theoretical approach, we model the epidemiology of an understudied mechanism of microbially-induced sex ratio distortion—feminisation—to ask an understudied question—how do SRDMs impact extinction risk in a changing environment? We constructed an individual-based model and measured host population extinction risk under various environmental and epidemiological scenarios. We also used our model to identify the precise mechanism modulating extinction. We find that the presence of feminisers increases host population extinction risk, an effect that is exacerbated in highly variable environments. We also identified transmission rate as the dominant epidemiological trait responsible for driving extinction. Finally, our model shows that sex ratio skew is the mechanism driving extinction. We highlight feminisers and, more broadly, SRDMs as important determinants of the resilience of arthropod populations to environmental change

Sex ratio distorting microbes exacerbate arthropod extinction risk in variable environments

Maternally-inherited sex ratio distorting microbes (SRDMs) are common among arthropod species. Typically, these microbes cause female-biased sex ratios in host broods, either by; killing male offspring, feminising male offspring, or inducing parthenogenesis. As a result, infected populations can experience drastic ecological and evolutionary change. The mechanism by which SRDMs operate is likely to alter their impact on host evolutionary ecology; despite this, the current literature is heavily biased towards a single mechanism of sex ratio distortion, male-killing. Furthermore, amidst the growing concerns surrounding the loss of arthropod diversity, research into the impact of SRDMs on the viability of arthropod populations is generally lacking. In this study, using a theoretical approach, we model the epidemiology of an understudied mechanism of microbially-induced sex ratio distortion—feminisation—to ask an understudied question—how do SRDMs impact extinction risk in a changing environment? We constructed an individual-based model and measured host population extinction risk under various environmental and epidemiological scenarios. We also used our model to identify the precise mechanism modulating extinction. We find that the presence of feminisers increases host population extinction risk, an effect that is exacerbated in highly variable environments. We also identified transmission rate as the dominant epidemiological trait responsible for driving extinction. Finally, our model shows that sex ratio skew is the mechanism driving extinction. We highlight feminisers and, more broadly, SRDMs as important determinants of the resilience of arthropod populations to environmental change

Lessons from a Marine Spatial Planning data management process for Ireland

Peer-reviewedThis paper presents a framework containing ten components to deliver a data management process for the storage and management of data used for Marine Spatial Planning (MSP) in Ireland. The work includes a data process flow and a recommended solution architecture. The architecture includes a central data catalogue and a spatial storage system. The components of the process are presented to maximise the reuse potential of any dataset within an MSP context. The terms ‘Suitability’ and ‘Readiness’ in the MSP context are offered as both formal and considered assessments of data, as is the applicability of a data stewardship maturity matrix. How data contained in such a storage system can be published externally to potential consumers of these data is also explored. The process presents a means of managing data and metadata to ensure data lineage is optimised by carrying information about the origin of and the processing applied to the data; to evaluate the quality and relevance of geospatial datasets for use in MSP decisions in Ireland. The process was piloted in the National Marine Planning Framework for Ireland in the development of draft map products; feedback from the public consultation is ongoing and not presented

Barriers to using new needles encountered by rural Appalachian people who inject drugs: implications for needle exchange

Background Using a new needle for every injection can reduce the spread of infectious disease among people who inject drugs (PWID). No previous study has examined new needle use barriers among PWIDs residing in the rural Appalachian part of the United States, an area currently in the midst of a heroin epidemic. Objective Therefore, our primary aim was to explore self-reported barriers to using a new needle by PWID attending a needle exchange program (NEP). Methods We conducted a cross-sectional survey of PWID attending two NEPs in rural West Virginia located in the heart of Central Appalachia. A convenience sample of PWID (n = 100) completed the Barriers to Using New Needles Questionnaire. Results The median number of barriers reported was 5 (range 0–19). Fear of arrest by police (72% of PWID “agreed” or “strongly agreed”) and difficulty with purchasing needles from a pharmacy (64% “agreed” or “strongly agreed”) were the most frequently cited barriers. Conclusions/Importance Congruent with previous findings from urban locations, in rural West Virginia, the ability of PWID to use a new needle obtained from a needle exchange for every injection may be compromised by fear of arrest. In addition, pharmacy sales of new needles to PWID may be blunted by an absence of explicit laws mandating nonprescription sales. Future studies should explore interventions that align the public health goals of NEPs with the occupational safety of law enforcement and health outreach goals of pharmacists

A New Multi-Ingredient Recipe for the Treatment of Localized Advanced Periodontal Disease following the Surgical Removal of Impacted Wisdom Teeth

Periodontal disease is a chronic inflammation of the tooth supporting structures. It leads to bone and attachment loss which is irreversible. Extraction of horizontally impacted lower third molar (L3M) teeth may result in localized periodontal pockets at the distal aspect of the adjacent lower second molars (L2M). We present a case of a 21-year-old male who suffered from a swelling and pain around his lower right second molar following surgical removal of a mesioangular impacted lower right third molar. We showed that oral hygiene measures, surgical access, mixture of autogenous and synthetic bone graft, and guided tissue regeneration (GTR) were enough to control the problem

Qualitative case study of needle exchange programs in the Central Appalachian region of the United States

Background The Central Appalachian region of the United States is in the midst of a hepatitis C virus epi- demic driven by injection of opioids, particularly heroin, with contaminated syringes. In response to this epidemic, several needle exchange programs (NEP) have opened to pro- vide clean needles and other supplies and services to people who inject drugs (PWID). How- ever, no studies have investigated the barriers and facilitators to implementing, operating, and expanding NEPs in less populous areas of the United States. Methods This qualitative case study consisted of interviews with program directors, police chiefs, law enforcement members, and PWID affiliated with two NEPs in the rural state of West Virginia. Interview transcripts were coded inductively and analyzed using qualitative data analysis software. Final common themes related to barriers and facilitators of past program open- ings, current program operations, and future program plans, were derived through a consen- sus of two data coders. Results Both NEPs struggled to find existing model programs, but benefited from broad community support that facilitated implementation. The largest operational barrier was the legal conun- drum created by paraphernalia laws that criminalize syringe possession. However, both PWID and law enforcement appreciated the comprehensive services provided by these pro- grams. Program location and transportation difficulties were additional noted barriers. Future program operations are threatened by funding shortages and bans, but necessitated by unexpected program demand. Conclusion Despite broad community support, program operations are threatened by growing partici- pant volumes, funding shortages, and the federal government’s prohibition on the use of funds to purchase needles. Paraphernalia laws create a legal conundrum in the form of criminal sanctions for the possession of needles, which may inadvertently promote needle sharing and disease transmission. Future studies should examine additional barriers to using clean needles provided by rural NEPs that may blunt the effectiveness of NEPs in pre- venting disease transmission

Age related diffusion and tractography changes in typically developing pediatric cervical and thoracic spinal cord

Background and objective: Diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) are two techniques that can measure white matter integrity of the spinal cord. Recently, DTI indices have been shown to change with age. The purpose of this study is (a) to evaluate the maturational states of the entire pediatric spinal cord using DTI and DTT indices including fractional anisotropy (FA), mean diffusivity (MD), mean length of white matter fiber tracts and tract density and (b) to analyze the DTI and DTT parameters along the entire spinal cord as a function of spinal cord levels and age. Method: A total of 23 typically developing (TD) pediatric subjects ranging in age from 6 to 16 years old (11.94 ± 3.26 (mean ± standard deviation), 13 females and 10 males) were recruited, and scanned using 3.0 T MR scanner. Reduced FOV diffusion tensor images were acquired axially in the same anatomical location prescribed for the T2-weighted images to cover the entire spinal cord (C1-mid L1 levels). To mitigate motion induced artifacts, diffusion directional images were aligned with the reference image (b0) using a rigid body registration algorithm performed by in-house software developed in Matlab (MathWorks, Natick, Massachusetts). Diffusion tensor maps (FA and MD) and streamline deterministic tractography were then generated from the motion corrected DTI dataset. DTI and DTT parameters were calculated by using ROIs drawn to encapsulate the whole cord along the entire spinal cord by an independent board certified neuroradiologist. These indices then were compared between two age groups (age group A = 6–11 years (n = 11) and age group B = 12–16 years (n = 12)) based on similar standards and age definitions used for reporting spinal cord injury in the pediatric population. Standard least squared linear regression based on a restricted maximum likelihood (REML) method was used to evaluate the relationship between age and DTI and DTT parameters. Results: An increase in FA (group A = 0.42 ± 0.097, group B = 0.49 ± 0.116), white matter tract density (group A = 368.01 ± 236.88, group B = 440.13 ± 245.24) and mean length of fiber tracts (group A = 48.16 ± 20.48 mm, group B = 60.28 ± 23.87 mm) and a decrease in MD (group A = 1.06 ± 0.23 × 10−3 mm2/s, group B = 0.82 ± 0.24 × 10−3 mm2/s) were observed with age along the entire spinal cord. Statistically significant increases have been shown in FA (p = 0.004, R2 = 0.57), tract density (p = 0.0004, R2 = 0.58), mean length of fiber tracts (p \u3c 0.001, R2 = 0.5) and a significant decrease has been shown in MD (p = 0.002, R2 = 0.59) between group A and group B. Also, it has been shown DTI and DTT parameters vary along the spinal cord as a function of intervertebral disk and mid-vertebral body level. Conclusion: This study provides an initial understanding of age related changes of DTI values as well as DTT metrics of the spinal cord. The results show significant differences in DTI and DTT parameters which may result from decreasing water content, myelination of fiber tracts, and the thickening diameter of fiber tracts during the maturation process. Consequently, when quantitative DTI and DTT of the spinal cord is undertaken in the pediatric population an age and level matched normative dataset should be used to accurately interpret the quantitative results. © 201

Analytic Inversion of Emission Lines of Arbitrary Optical Depth for the Structure of Supernova Ejecta

We derive a method for inverting emission line profiles formed in supernova ejecta. The derivation assumes spherical symmetry and homologous expansion (i.e., $v(r) \propto r$), is analytic, and even takes account of occultation by a pseudo-photosphere. Previous inversion methods have been developed which are restricted to optically thin lines, but the particular case of homologous expansion permits an analytic result for lines of {\it arbitrary} optical depth. In fact, we show that the quantity that is generically retrieved is the run of line intensity $I_\lambda$ with radius in the ejecta. This result is quite general, and so could be applied to resonance lines, recombination lines, etc. As a specific example, we show how to derive the run of (Sobolev) optical depth $\tau_\lambda$ with radius in the case of a pure resonance scattering emission line.Comment: 6 pages, no figures, to appear in Astrophysical Journal Letters, requires aaspp4.sty to late

Being the ‘med reg’: an exploration of junior doctors’ perceptions of the medical registrar role

The role of the medical registrar is a challenging one and is acknowledged as being a disincentive to a career in medicine for some junior doctors. We set out to build a broader understanding of the role through exploration of Foundation Doctors’ and Core Medical Trainees’ perceptions of the role. Data, gathered from focus groups, were analysed using a framework approach. Six key themes were identified, which were grouped under the headings ‘perceptions of the medical registrar role’ and ‘transition into the role’. Our work builds on existing literature to inform a deeper understanding of how junior doctors perceive the medical registrar role. In light of our findings we offer suggestions on possible training initiatives to tackle the issues identified. We also highlight positive perceptions of the role and emphasise the key ambassadorial role that current medical registrars have in relation to attracting tomorrows’ medical registrars to the specialty