1,706 research outputs found
A hypervelocity star with a Magellanic origin
Using proper motion measurements from Gaia DR2, we probe the origin of 26
previously known hypervelocity stars (HVSs) around the Milky Way. We find that
a significant fraction of these stars have a high probability of originating
close to the Milky Way centre, but there is one obvious outlier. HVS3 is highly
likely to be coming almost from the centre of the Large Magellanic Cloud (LMC).
During its closest approach, Myr ago, it had a relative
velocity of kms with respect to the LMC. This large
kick velocity is only consistent with the Hills mechanism, requiring a massive
black hole at the centre of the LMC. This provides strong direct evidence that
the LMC itself harbours a massive black hole of at least .Comment: 7 pages, 9 figures. Submitted to MNRAS. Comments welcome
Antibacterial activity of matrix-bound ovotransferrin
Ovotransferrin immobilized by covalent linkage to Sepharose 4B showed a bacteriostatic effect towards Escherichia coli similar to that of free ovotransferrin. The growth of the bacteria, after exposure to the gel-bound ovotransferrin and its removal, depended on the length of exposure. The results suggest that the antibacterial activity of transferrin is not due simply to the removal of iron from the medium
Dominant BIN1-related centronuclear myopathy (CNM) revealed by lower limb myalgia and moderate CK elevation
We report a BIN1-related CNM family with unusual clinical phenotype. The proband, a 56-year-old man suffered of lower limbs myalgia since the age of 52. Clinical examination showed short stature, mild symmetric eyelid ptosis without ophthalmoplegia, scapular winging and Achilles tendon retraction. A muscle weakness was not noted. CK levels were up to 350 UI/L. Deltoid muscle biopsy showed nuclear centralization and clustering, deep sarcolemmal invaginations and type 1 fiber hypotrophy. Whole body MRI revealed fatty infiltration of posterior legs compartments, lumbar paraspinal and serratus muscles. Myotonic dystrophy type1 and 2, Pompe disease and MTM1 and DNM2-related CNM were ruled out. By sequencing BIN1, we identified a heterozygous pathogenic mutation [c.107C > A (p.A36E)], and we demonstrate that the mutation strongly impairs the membrane tubulation property of the protein. One affected sister carried the same mutation. Her clinical examination and muscle MRI revealed a similar phenotype. Our findings expand the clinical and genetic spectrum of the autosomal dominant CNM associated with BIN1 mutations
Recommended from our members
VOF simulations of the contact angle dynamics during the drop spreading: Standard models and a new wetting force model
Introduction
In this study,a novel numerical implementation for the adhesion of liquid droplets impacting normally on solid dry surfaces is presented. The advantage of this new approach, compared to the majority of existing models, is that the dynamic contact angle forming during the surface wetting process is not inserted as a boundary condition, but is derived implicitly by the induced fluid flow characteristics (interface shape) and the adhesion physics of the gas-liquid-surface interface (triple line), starting only from the advancing and receding equilibrium contact angles. These angles are required in order to define the wetting properties of liquid phases when interacting with a solid surface.
Methodology
The physical model is implemented as a source term in the momentum equation of a Navier-Stokes CFD flow solver as an "adhesion-like" force which acts at the triple-phase contact line as a result of capillary interactions between the liquid drop and the solid substrate. The numerical simulations capture the liquid-air interface movement by considering the volume of fluid (VOF) method and utilizing an automatic local grid refinement technique in order to increase the accuracy of the predictions at the area of interest, and simultaneously minimize numerical diffusion of the interface.
Results
The proposed model is validated against previously reported experimental data of normal impingement of water droplets on dry surfaces at room temperature. A wide range of impact velocities, i.e. Weber numbers from as low as 0.2 up to 117, both for hydrophilic (θadv = 10° - 70°) and hydrophobic (θadv = 105° - 120°) surfaces, has been examined. Predictions include in addition to droplet spreading dynamics, the estimation of the dynamic contact angle; the latter is found in reasonable agreement against available experimental measurements.
Conclusion
It is thus concluded that theimplementation of this model is an effective approach for overcoming the need of a pre-defined dynamic contact angle law, frequently adopted as an approximate boundary condition for such simulations. Clearly, this model is mostly influential during the spreading phase for the cases of low We number impacts (We <80) since for high impact velocities, inertia dominates significantly over capillary forces in the initial phase of spreading
The Relationship between Trail Running Withdrawals and Race Topography
Context: A growing amount of recent research in sport psychology has focused on
trying to understand withdrawals from ultra-races. However, according to the Four E approach,
the studies underestimated the embedded components of these experiences and particularly how
they were linked to the specific environmental conditions in which the experiences occurred.
Objective: This study aimed to characterize trail running withdrawals in relationship to race
topography. Design: Qualitative design, involving self-confrontation interviews and use of a race
map. Setting: Use of the race map for description of the race activity and self-confrontation interviews
took place 1–3 days after the races. Participants: Ten runners who withdrew during an ultra-trail
race. Data Collection and Analysis: Data on past activity traces and experiences were elicited from
self-confrontation interviews. Data were coded and compared to identify common sequences and
then each type of sequence was counted with regard to race topography. Results: Results showed
that each sequence was related to runners’ particular possibilities for acting, feeling, and thinking,
which were in turn embedded in the race topography. These sequences allowed the unfolding
of the activity and increased its overall effectiveness in relation to the constraints of this specific
sport. Conclusion: This study allowed us to highlight important information on how ultra-trail
runners manage their races in relationship to the race environment and more specifically to its
topography. The result will also help us to recommend potential adjustments to ultra-trail runners’
performance-oriented training and preparation
Recommended from our members
Numerical investigation of droplet impingement onto hydrophobic and super-hydrophobic solid surfaces. The effect of Weber number and wettability
In this study, a new model for the wetting interaction between a liquid droplet and a solid surface is presented. Based on this model, a force which acts on the contact line is incorporated as a source term in the Navier-Stokes momentum equation. The advantage of the new model in comparison with the widely-used Brackbill’s model is that the contact angle is not inserted as a boundary condition, but is derived by the induced fluid flow and the adhesion physics of the liquid-surface combination. For the interface tracking, the Volume of Fluid (V.O.F) method is used, accompanied by an automatic local grid refinement technique in order to minimize the arithmetic diffusion of volume fraction and thus acquire more representative physical results. The new model is validated against experimental data for low and moderate We numbers both for hydrophilic and superhydrophobic surfaces. Results of the model are also compared against the standard Brackbill’s model for the implementation of the wetting force. The apparent contact angle during droplet spreading and recoiling is plotted in order to gain insight on the dynamic angle temporal evolution during the impingement process
Comparison of vitality states of finishers and withdrawers in trail running: An enactive and phenomenological perspective.
Studies on ultra-endurance suggest that during the races, athletes typically experience three vitality states (i.e., preservation, loss, and revival) at the phenomenological level. Nevertheless, how these states contribute to the management and outcome of performance remains unclear. The aim of this study was to determine whether and how the vitality states experienced by runners and their evolution during a trail race can be used to distinguish finishers from withdrawers. From an enactive and phenomenological framework, we processed enactive interviews and blog posts of race narratives. We distinguished units of meaning, which were grouped into sequences of experience; each sequence was then categorized as one of the three vitality states: state of vitality preservation (SVP), state of vitality loss (SVL) or state of vitality revival (SVR). We analyzed the distribution of these vitality states and their temporal organization at the beginning, in the second and third quarters, and at the end of the races, and we qualitatively characterized runners' adaptations to SVL. Results showed that finishers completed the race in SVP, with overall significantly more sequences in SVP and significantly fewer sequences in SVL than withdrawers. SVR did not discriminate finishers from withdrawers. The temporal organization of the vitality states showed a significant difference in the emergence of SVP from the second quarter of the race, as well as a significant difference in the emergence of SVL from the third quarter of the race. The analysis of adaptations to SVL confirmed that finishers were more capable of exiting SVL by enacting a preservation world when they felt physical or psychological alerts, whereas withdrawers remained in SVL. Our results showed that finishers and withdrawers did not enact the same phenomenological worlds in the race situation, especially in the organization of vitality adaptations and their relationships to difficulties; the cumulative effect of the succession of experienced vitality states differed, as well
The Application of Hyaluronic Acid Injections in Functional and Aesthetic Andrology: A Narrative Review
Hyaluronic acid (HA) is a glycosaminoglycan widely utilised in different fields of medicine. We aimed to provide a comprehensive overview of the scientific evidence on the use of HA in andrology. A review of the literature to identify pertinent studies concerning the use of HA in andrology was carried out on the Medline, EMBASE, and the Cochrane databases, with no time restriction up to December 2022. Penile girth enlargement (PGE) using HA proved to be safe and effective in enhancing the diameter of the penis, with durable and satisfactory outcomes in long-term follow-up. Injection of HA in the glans seems to represent an alternative treatment option for those patients with premature ejaculation (PE) who fail to respond to conventional medications. HA intra-plaque injections represent a valid option which may contribute to restore sexual activity in patients with Peyronie's disease (PD). The adoption of HA filler injections should always be tailored to the patient's peculiar anatomy and underlying condition. More robust evidence is required to achieve a uniformed consensus regarding the use of HA in andrology, and further efforts should continue to improve the current injection techniques and HA products
The Possible Role of Prescribing Medications, Including Central Nervous System Drugs, in Contributing to Male-Factor Infertility (MFI): Assessment of the Food and Drug Administration (FDA) Pharmacovigilance Database
Background: A wide range of medications may have a possible role in the development of male-factor infertility (MFI), including various antineoplastic agents, testosterone/anabolic steroids, immunosuppressive drugs/immunomodulators, glucocorticosteroids, non-steroidal anti-inflammatory drugs, opiates, antiandrogenic drugs/5-alpha-reductase inhibitors, various antibiotics, antidepressants, antipsychotics, antiepileptic agents and others. We aimed at investigating this issue from a pharmacovigilance-based perspective. Methods: The Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database was queried to identify the drugs associated the most with MFI individual reports. Only those drugs being associated with more than 10 MFI reports were considered for the disproportionality analysis. Proportional Reporting Ratios (PRRs) and their confidence intervals were computed for all the drugs identified in this way in January 2023. Secondary, ‘unmasking’, dataset analyses were carried out as well. Results: Out of the whole database, 955 MFI reports were identified, 408 (42.7%) of which were associated with 20 medications, which had more than 10 reports each. Within this group, finasteride, testosterone, valproate, diethylstilbestrol, mechloretamine, verapamil, lovastatin and nifedipine showed significant levels of actual disproportionate reporting. Out of these, and before unmasking, the highest PRR values were identified for finasteride, diethylstilbestrol and mechloretamine, respectively, with values of 16.0 (12.7–20.3), 14.3 (9.1–22.4) and 58.7 (36.3–95.9). Conclusions: A variety of several medications, a number of which were already supposed to be potentially linked with MFI based on the existing evidence, were associated with significant PRR levels for MFI in this analysis. A number of agents which were previously hypothesized to be associated with MFI were not represented in this analysis, suggesting that drug-induced MFI is likely under-reported to regulatory agencies. Reproductive medicine specialists should put more effort into the detection and reporting of these adverse drug reactions
- …