The discrepancy in G-band contrast: Where is the quiet Sun?

We compare the rms contrast in observed speckle reconstructed G-band images with synthetic filtergrams computed from two magneto-hydrodynamic simulation snapshots. The observations consist of 103 bursts of 80 frames each taken at the Dunn Solar Telescope (DST), sampled at twice the diffraction limit of the telescope. The speckle reconstructions account for the performance of the Adaptive Optics (AO) system at the DST to supply reliable photometry. We find a considerable discrepancy in the observed rms contrast of 14.1% for the best reconstructed images, and the synthetic rms contrast of 21.5% in a simulation snapshot thought to be representative of the quiet Sun. The areas of features in the synthetic filtergrams that have positive or negative contrast beyond the minimum and maximum values in the reconstructed images have spatial scales that should be resolved. This leads us to conclude that there are fundamental differences in the rms G-band contrast between observed and computed filtergrams. On the basis of the substantially reduced granular contrast of 16.3% in the synthetic plage filtergram we speculate that the quiet-Sun may contain more weak magnetic field than previously thought.Comment: 16 pages, 8 figure

Multiple Projection Optical Diffusion Tomography with Plane Wave Illumination

We describe a new data collection scheme for optical diffusion tomography in which plane wave illumination is combined with multiple projections in the slab imaging geometry. Multiple projection measurements are performed by rotating the slab around the sample. The advantage of the proposed method is that the measured data can be much more easily fitted into the dynamic range of most commonly used detectors. At the same time, multiple projections improve image quality by mutually interchanging the depth and transverse directions, and the scanned (detection) and integrated (illumination) surfaces. Inversion methods are derived for image reconstructions with extremely large data sets. Numerical simulations are performed for fixed and rotated slabs

Factors Influencing Graduate Program Choice Among Undergraduate Women

Context: Despite equal enrollment proportions in MD and PhD programs, there are fewer women than men in MD-PhD programs and academic medicine. Factors important in degree program selection, including the perception of gender disparities, among undergraduate students were characterized. Methods: In 2017, pre-health students at four public North Carolina universities were invited to participate in an online survey regarding career plans, decision factors, and perceptions of gender disparities in MD, PhD and MD-PhD pathways. The authors characterized factors important to program selection, and evaluated the association of intended graduate program with perceived gender disparities using Fisher’s exact tests. Results: Among the n=186 female survey participants, most were white (54%) and intended MD, PhD, and/or MD-PhD programs (52%). Sixty percent had heard of MD-PhD programs, over half had no research experience, and half were considering but uncertain about pursuing a research career. The most common factors influencing degree program choice were perceived competitiveness as an applicant, desired future work environment, and desire for patient interaction. Twenty-five percent of students considering MD, PhD, and MD-PhD programs stated that perceived gender disparities during training for those degrees will influence their choice of program, however intended degree was not statistically associated with perceived gender disparities. Discussion: Perceived gender disparities may influence choice of graduate training program but are not among the top factors. Perceived competitiveness as an applicant is an important career consideration among undergraduate women. Strategies to increase awareness of MD-PhD programs, to encourage women to consider all training paths for which they are qualified are needed. Keywords: Education, Graduate; Sexism; Career Choice; Biomedical Research/education; Female What is known: Though men and women are nearly equally represented in MD-only and PhD-only programs, women are underrepresented in MD-PhD programs, which train physician-scientists. Prior studies have shown gender is not associated with rates of attrition from MD-PhD programs or differences in academic preparation, research interest, or research experience, suggesting enrollment differences by gender may be due to fewer women applying to MD-PhD programs. Gender parity in the physician-scientist workforce is critical to equitably serving a diverse patient population. What this study adds: This study is the first to examine the role of gender disparities in the career choices of undergraduate women. Given the moderate familiarity with MD-PhD training and lack of research experience among respondents, increased awareness of MD-PhD programs and expanded research opportunities may help undergraduates make informed career choices. This may increase women MD-PhD applicants, creating a more balanced physician-scientist workforce to address the needs of patients from all backgrounds

Helicase on DNA: A Phase coexistence based mechanism

We propose a phase coexistence based mechanism for activity of helicases, ubiquitous enzymes that unwind double stranded DNA. The helicase-DNA complex constitutes a fixed-stretch ensemble that entails a coexistence of domains of zipped and unzipped phases of DNA, separated by a domain wall. The motor action of the helicase leads to a change in the position of the fixed constraint thereby shifting the domain wall on dsDNA. We associate this off-equilibrium domain wall motion with the unzipping activity of helicase. We show that this proposal gives a clear and consistent explanation of the main observed features of helicases.Comment: Revtex4. 5 pages. 4 figures. Published versio

Are autistic traits measured equivalently in individuals with and without an Autism Spectrum Disorder?:An invariance analysis of the Autism Spectrum Quotient Short Form

It is common to administer measures of autistic traits to those without autism spectrum disorders (ASDs) with, for example, the aim of understanding autistic personality characteristics in non-autistic individuals. Little research has examined the extent to which measures of autistic traits actually measure the same traits in the same way across those with and without an ASD. We addressed this question using a multi-group confirmatory factor invariance analysis of the Autism Quotient Short Form (AQ-S: Hoekstra et al. in J Autism Dev Disord 41(5):589-596, 2011) across those with (n = 148) and without (n = 168) ASD. Metric variance (equality of factor loadings), but not scalar invariance (equality of thresholds), held suggesting that the AQ-S measures the same latent traits in both groups, but with a bias in the manner in which trait levels are estimated. We, therefore, argue that the AQ-S can be used to investigate possible causes and consequences of autistic traits in both groups separately, but caution is due when combining or comparing levels of autistic traits across the two group

Clinical findings, treatment, and outcome of trapped neutrophil syndrome in Border Collies: 12 cases (2011-2022)

Objectives: This study aimed to evaluate clinical signs, diagnostic findings, treatment administered and short- (survival to 28 days) and long-term prognosis (survival &gt;6 months) in dogs diagnosed with trapped neutrophil syndrome. Materials and Methods: Medical records of 12 dogs (10 Border Collies and two Border Collie Crossbreeds) homozygous for VPS13B gene mutation causing trapped neutrophil syndrome from seven veterinary institutions between January 2011 and June 2022 were evaluated retrospectively. Results: The most common clinical signs at the time of diagnosis were pyrexia, abnormal gait and gastrointestinal signs. Concurrent metaphyseal osteopathy and immune-mediated polyarthritis were common. Seven dogs had a segmented neutrophil count below, four dogs within and one dog above the analyser reference interval at presentation. Two dogs had a septic source identified and both were additionally identified to be homozygous mutant positive on DNA testing by polymerase chain reaction (PCR) for canine cyclic neutropenia. All dogs received at least one antimicrobial agent and 10 dogs received treatment with prednisone or prednisolone (median starting dose 1 mg/kg/day; range 0.5 to 2.5 mg/kg/day). Nine dogs were alive at 28 days and six dogs were alive at 6 months post-diagnosis. Clinical Significance: Trapped neutrophil syndrome should be suspected in young Border Collies with pyrexia, lameness and gastrointestinal signs. Neutropenia may not always be present and long-term survival is possible. A septic focus was not commonly identified in our population; however, our results suggest that if identified, testing for concurrent canine cyclic neutropenia should be considered.</p

Formyltetrahydrofolate Synthetase Gene Diversity in the Guts of Higher Termites with Different Diets and Lifestyles

In this study, we examine gene diversity for formyl-tetrahydrofolate synthetase (FTHFS), a key enzyme in homoacetogenesis, recovered from the gut microbiota of six species of higher termites. The "higher" termites (family Termitidae), which represent the majority of extant termite species and genera, engage in a broader diversity of feeding and nesting styles than the "lower" termites. Previous studies of termite gut homoacetogenesis have focused on wood-feeding lower termites, from which the preponderance of FTHFS sequences recovered were related to those from acetogenic treponemes. While sequences belonging to this group were present in the guts of all six higher termites examined, treponeme-like FTHFS sequences represented the majority of recovered sequences in only two species (a wood-feeding Nasutitermes sp. and a palm-feeding Microcerotermes sp.). The remaining four termite species analyzed (a Gnathamitermes sp. and two Amitermes spp. that were recovered from subterranean nests with indeterminate feeding strategies and a litter-feeding Rhynchotermes sp.) yielded novel FTHFS clades not observed in lower termites. These termites yielded two distinct clusters of probable purinolytic Firmicutes and a large group of potential homoacetogens related to sequences previously recovered from the guts of omnivorous cockroaches. These findings suggest that the gut environments of different higher termite species may select for different groups of homoacetogens, with some species hosting treponeme-dominated homoacetogen populations similar to those of wood-feeding, lower termites while others host Firmicutes-dominated communities more similar to those of omnivorous cockroaches

Synthesis of Fluorine-18 Functionalized Nanoparticles for use as in vivo Molecular Imaging Agents

Nanoparticles containing fluorine-18 were prepared from block copolymers made by ring opening metathesis polymerization (ROMP). Using the fast initiating ruthenium metathesis catalyst (H_2IMes)(pyr)_2(Cl)_2Ru=CHPh, low polydispersity amphiphilic block copolymers were prepared from a cinnamoyl-containing hydrophobic norbornene monomer and a mesyl-terminated PEG-containing hydrophilic norbornene monomer. Self-assembly into micelles and subsequent cross-linking of the micelle cores by light-activated dimerization of the cinnamoyl groups yielded stable nanoparticles. Incorporation of fluorine-18 was achieved by nucleophilic displacement of the mesylates by the radioactive fluoride ion with 31% incorporation of radioactivity. The resulting positron-emitting nanoparticles are to be used as in vivo molecular imaging agents for use in tumor imaging