Gonadal Restructuring During Sex Transition in California Sheephead: a Reclassification Three Decades After Initial Studies

California Sheephead, Semicossyphus pulcher, is a monandric protogynous hermaphrodite and a commercially and recreationally valuable labrid. Gonadal functionality of Sheephead through sex change was reclassified into nine classes using current criteria for categorization. Female ovaries were classified as immature, early maturing, mature, and regressing/recovering classes. Transition from female to male and subsequent male development was divided into early, mid and late transitional, developing/active male and regressing/recovering male. Reproductive states in Sheephead were correlated with estradiol (E2) and 11-keto testosterone (11-KT) concentrations in the blood plasma. All sexes had low E2 concentrations in the fall /winter seasons; in transitional and male individuals, levels remained low throughout the year. In contrast, female E2 concentrations were elevated in spring and peaked in the summer. Concentrations of 11-KT were variable throughout the year; however, females had significantly lower levels in the summer. This study allows a better understanding of the current state of California Sheephead in a heavily fished area. Knowledge of a species’ reproductive characteristics is important in evaluating the sustainability of a population as it can set a baseline for reproductive potential. This research takes a critical step in gathering and organizing reproductive data such that it may be used in future studies for comparing reproductive potential across the range of the California sheephead

Active current sheets and hot flow anomalies in Mercury's bow shock

Hot flow anomalies (HFAs) represent a subset of solar wind discontinuities interacting with collisionless bow shocks. They are typically formed when the normal component of motional (convective) electric field points toward the embedded current sheet on at least one of its sides. The core region of an HFA contains hot and highly deflected ion flows and rather low and turbulent magnetic field. In this paper, we report first observations of HFA-like events at Mercury identified over a course of two planetary years. Using data from the orbital phase of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission, we identify a representative ensemble of active current sheets magnetically connected to Mercury's bow shock. We show that some of these events exhibit unambiguous magnetic and particle signatures of HFAs similar to those observed earlier at other planets, and present their key physical characteristics. Our analysis suggests that Mercury's bow shock does not only mediate the flow of supersonic solar wind plasma but also provides conditions for local particle acceleration and heating as predicted by previous numerical simulations. Together with earlier observations of HFA activity at Earth, Venus and Saturn, our results confirm that hot flow anomalies are a common property of planetary bow shocks, and show that the characteristic size of these events is of the order of one planetary radius.Comment: 39 pages, 15 figures, 2 table

Casimir Energy For a Massive Dirac Field in One Spatial Dimension: A Direct Approach

In this paper we calculate the Casimir energy for a massive fermionic field confined between two points in one spatial dimension, with the MIT Bag Model boundary condition. We compute the Casimir energy directly by summing over the allowed modes. The method that we use is based on the Boyer's method, and there will be no need to resort to any analytic continuation techniques. We explicitly show the graph of the Casimir energy as a function of the distance between the points and the mass of the fermionic field. We also present a rigorous derivation of the MIT Bag Model boundary condition.Comment: 8 Pages, 4 Figure

Evaluation of simulated responses to climate forcings: a flexible statistical framework using confirmatory factor analysis and structural equation modelling – Part 1: Theory

Evaluation of climate model simulations is a crucial task in climate research. Here, a new statistical framework is proposed for evaluation of simulated temperature responses to climate forcings against temperature reconstructions derived from climate proxy data for the last millennium. The framework includes two types of statistical models, each of which is based on the concept of latent (unobservable) variables: confirmatory factor analysis (CFA) models and structural equation modelling (SEM) models. Each statistical model presented is developed for use with data from a single region, which can be of any size. The ideas behind the framework arose partly from a statistical model used in many detection and attribution (D&amp;A) studies. Focusing on climatological characteristics of five specific forcings of natural and anthropogenic origin, the present work theoretically motivates an extension of the statistical model used in D&amp;A studies to CFA and SEM models, which allow, for example, for non-climatic noise in observational data without assuming the additivity of the forcing effects. The application of the ideas of CFA is exemplified in a small numerical study, whose aim was to check the assumptions typically placed on ensembles of climate model simulations when constructing mean sequences. The result of this study indicated that some ensembles for some regions may not satisfy the assumptions in question.</p

Skills, attitudes and uptake of evidence-based practice: a cross-sectional study of chiropractors in the Swedish Chiropractic Association.

BackgroundEvidence-based practice (EBP) is integral to the delivery of high-quality health care. Chiropractic has been a licensed health profession in Sweden since 1989, but little is known of the uptake of EBP in this professional group. This study explored the self-reported skills, attitudes and uptake of EBP, and the enablers and barriers of EBP uptake, among licensed chiropractors in Sweden.MethodsLicensed chiropractors (n = 172) of the Swedish Chiropractic Association (Legitimerade Kiropraktorers Riksorganisation) were invited to participate in an anonymous online questionnaire, using the Evidence-Based Practice Attitude and Utilisation Survey (EBASE) in February 2019.ResultsFifty-six (33%) chiropractors completed the survey. Participants were predominantly male, aged 30-49 years, held a Master's degree, and had received their highest qualification and practiced chiropractic for over a decade. Chiropractors rated their EBP skill-level mostly in the moderate to moderate-high range. The majority of chiropractors reported positive attitudes towards EBP, with most agreeing or strongly agreeing that EBP is necessary in the practice of chiropractic, and that EBP assists in making decisions about patient care. Chiropractors reported an average level of engagement in EBP activities. All participants indicated professional literature and research findings were useful in their day-to-day chiropractic practice. The main perceived enabler of EBP uptake was internet access in the workplace, whereas the main barrier to EBP uptake was lack of clinical evidence in chiropractic.ConclusionsParticipating chiropractors of the Swedish Chiropractic Association were generally favourable of EBP, though only reported modest levels of EBP-related skills and engagement in EBP activities. Our findings suggest future studies investigating interventions focussed on improving chiropractors' skills and uptake of EBP are warranted

Reconstruction of Propagating Kelvin-Helmholtz Vortices at Mercury's Magnetopause

A series of quasi-periodic magnetopause crossings were recorded by the MESSENGER spacecraft during its third flyby of Mercury on 29 September 2009, likely caused by a train of propagating Kelvin-Helmholtz (KH) vortices. We here revisit the observations to study the internal structure of the waves. Exploiting MESSENGER s rapid traversal of the magnetopause, we show that the observations permit a reconstruction of the structure of a rolled-up KH vortex directly from the spacecraft s magnetic field measurements. The derived geometry is consistent with all large-scale fluctuations in the magnetic field data, establishes the non-linear nature of the waves, and shows their vortex-like structure. In several of the wave passages, a reduction in magnetic field strength is observed in the middle of the wave, which is characteristic of rolled-up vortices and is related to the increase in magnetic pressure required to balance the centrifugal force on the plasma in the outer regions of a vortex, previously reported in computer simulations. As the KH wave starts to roll up, the reconstructed geometry suggests that the vortices develop two gradual transition regions in the magnetic field, possibly related to the mixing of magnetosheath and magnetospheric plasma, situated at the leading edges from the perspectives of both the magnetosphere and the magnetosheath

Flanging and Hemming of Auto Body Panels using the Electro Magnetic Forming technology

Electro Magnetic Forming (EMF) technology has a great number of potential applications for the automotive industry. LABEIN-Tecnalia has worked with this technology for six years and has a good understanding of the automotive industry s needs and challenges. LABEIN-Tecnalia is currently developing new applications with EMF technology. Taking into account the advantages and limitations of EMF, bending and hemming processes present good geometric conditions for the use of this technology. The study presented is based largely on hemming circular configurations which are simplifications of those commonly used on hemmed automotive parts. The parameters of this new EMF bending and hemming processes have been studied, as well as their influence on the final quality of the parts obtained. Conclusions obtained from the basic geometries were tested on a more complicated geometry in order to apply the knowledge acquired. Parallel to the experimental work, fully coupled electromechanical software by LS-DYNA has been used to simulate and extend the present hemming results