625 research outputs found

    Dark matter and stable bound states of primordial black holes

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    We present three reasons for the formation of gravitational bound states of primordial black holes,called holeums,in the early universe.Using Newtonian gravity and nonrelativistic quantum mechanics we find a purely quantum mechanical mass-dependant exclusion property for the nonoverlap of the constituent black holes in a holeum.This ensures that the holeum occupies space just like ordinary matter.A holeum emits only gravitational radiation whose spectrum is an exact analogue of that of a hydrogen atom. A part of this spectrum lies in the region accessible to the detectors being built.The holeums would form haloes around the galaxies and would be an important component of the dark matter in the universe today.They may also be the constituents of the invisible domain walls in the universe.Comment: 13 pages,2tables,for wider circulation,PD

    Physical characteristics underpinning lunging and change of direction speed in fencing

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    Lunge velocity (LV) and change of direction speed (CODS) are considered fundamental to success during fencing competitions; investigating the physical characteristics that underpin these is the aim of this study. Seventy fencers from the British Fencing National Academy took part and on average (± SD) were 16.83 ± 1.72 years of age, 178.13 ± 8.91 cm tall, 68.20 ± 9.64 kg in mass and had 6.25 ± 2.23 years fencing experience. The relationship between anthropometric characteristics (height, arm-spam and adductor flexibility) and measures of lower-body power (bilateral and unilateral countermovement jump height and reactive strength index) were examined in their ability to influence LV and CODS. In testing the former, fencers lunged (over a self-selected distance) to and from a force plate, where front leg impact and rear leg propulsive force was quantified; the lunging distance was divided by time to establish LV. CODS was measured over 12 m involving shuttles of between 2 and 4 m. Results revealed that LV and CODS averaged at 3.35 m/s and 5.45 s respectively and in both cases, standing broad jump was the strongest predictor (r = 0.51 and -0.65 respectively) of performance. Rear leg drive and front leg impact force averaged at 14.61 N/kg and 3-times bodyweight respectively, with single leg jumps revealing an asymmetry favoring the front leg of 9%. In conclusion, fencers should train lower-body power emphasizing horizontal displacement, noting that this seems to offset any advantage one would expect fencers of a taller stature to have. Also, the commonly reported asymmetry between legs is apparent from adolescence and thus also requires some attention

    Reverse engineering in strength and conditioning: applications to agility training

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    Typically, a coach may follow a process in which they first identify the key performance indicators of their sport, determine the physical attributes that map back to them, and then distribute the development of those capacities over the allocated timeframe. Furthermore, effective training plans are based on a theoretical or biological basis for how we move and adapt to exercise stimuli, coupled with an understanding of how these are best sequenced, such that one stimulus and subsequent adaptation can potentiate the next. Thus, reverse or backward engineering, when appropriately converged with the plans of those devised around nutrition, conditioning, technical, and tactical training for example likely gives athletes the best chance of attaining their performance goals. The aim of this paper is to describe the application of reverse engineering, exampling it within the context of developing an athlete who can demonstrate a high level of agility

    Physical characteristics underpinning repetitive lunging in fencing

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    Given the repetitive demand to execute lunging and changes in direction within fencing, the ability to sustain these at maximal capacity is fundamental to performance. The aim of this study was threefold. Firstly to provide normative values for this variable referred to as repeat lunge ability (RLA) and secondly to identify the physical characteristics that underpin it. Thirdly, was to establish if a cause and effect relationship existed by training the associated characteristics. Assessment of lower body power, reactive strength, speed, change of direction speed (CODS) and a sport specific RLA were conducted on senior and junior elite male fencers (n = 36). Fencers were on average (± SD) 18.9 ± 3.2 years of age, 174.35 ± 10.42 cm tall, 70.67 ± 7.35 kg in mass, and 8.5 ± 4.2 years fencing experience. The RLA test had average work times of 16.03 s ± 1.40 and demonstrated "large" to "very large" associations with all tested variables, but in particular CODS (r = .70) and standing broad jump (SBJ; r = -68). Through linear regression analysis, these also provided a two-predictor model accounting for 61% of the common variance associated with RLA. A cause and effect relationship with SBJ and CODS was confirmed by the training group, where RLA performance in these fencers improved from 15.80 ± 1.07 s to 14.90 ± 0.86 s, with the magnitude of change reported as "moderate" (ES = 0.93). Concurrent improvements were also noted in both SBJ (216.86 cm ± 17.15 vs. 221.71 ± 17.59 cm) and CODS (4.44 ± 0.29 s s. 4.31 ± 0.09 s) and while differences were only significant in SBJ, magnitudes of change were classed as "small" (ES = 0.28) and "moderate" (ES = 0.61)respectively. In conclusion, to improve RLA strength and conditioning coaches should focus on improving lower-body power and reactive strength, noting that jump training and plyometrics designed to enhance horizontal propulsion may be most effective, and translate to improvement in CODS also

    Drug utilization study in the inpatients of pediatric department of a tertiary care hospital

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    Background: Infants and children constitute a large proportion of the population in developing countries. In Gujarat, studies on drug use patterns in the pediatric age group are lacking in the Saurashtra region hospitals. The objective was to study demographical information and the utilization pattern in the in patients of the pediatric ward.Methods: A cross-sectional, observational drug utilization study was carried out over a period of 6 months in 630 pediatric inpatients of the pediatric department of Guru Gobind Singh Hospital, Jamnagar, a tertiary care teaching hospital. Analyzed data included demographic details and drugs prescribed in respective patients.Results: Most commonly affected age group was 1-5 years, boys in 62.06% and girls in 37.94% and 40.16% were admitted in the pediatric ward. Acute gastroenteritis and pneumonia had the highest admission rate with 31.90% and 22.38%, respectively. The majority of children were prescribed 5-6 drugs. Ceftriaxone (64.92%) was the top most frequently prescribed antibiotic, followed by amoxicillin (49.21%). Prescribing drugs were mainly from essential drug list (64.44%) and by generic names (61.89%). Drugs prescribed orally in 66.10% and by injections in 33.90%.Conclusion: It is quite evident that significantly large number of children were from 1 to 5 year age group. The majority of the children were admitted in inpatients of the pediatric ward for acute gastroenteritis, followed by pneumonia and meningitis. Most frequently prescribed antibiotic group was cephalosporin, followed by penicillin group

    DT‐PACE/ESHAP chemotherapy regimens as salvage therapy for multiple myeloma prior to autologous stem cell transplantation

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    Routine use of novel agents to treat newly diagnosed and relapsed multiple myeloma (MM) produces high response rates and improved survival. However, 15–20% of patients have suboptimal responses and their management remains challenging.1 Traditional regimens, such as DT‐PACE (dexamethasone, thalidomide, cisplatin, doxorubicin, cyclophosphamide, etoposide) and ESHAP (etoposide, methylprednisolone, cytarabine, cisplatin) are employed in patients with relapsed/refractory (RR) disease, and may bridge patients to autologous stem cell transplantation (ASCT).2-4 Originally developed to improve responses to traditional chemotherapy regimens, and enable stem cell mobilization,5-7 the role of infusional regimens in the context of novel agents is unclear, especially as recently reported series indicate relatively poor outcomes.8, 9 These regimens can be associated with significant toxicity,2 placing a burden on healthcare resources.10 We undertook a single‐centre retrospective analysis to assess the role of infusional regimens in RR MM patients to explore and identify features associated with clinical benefit. Relevant clinical information was obtained from electronic records. Overall response rate (ORR) and cytogenetic risk were assessed as per International Myeloma Working Group (IMWG) criteria (Table I).11 [Progression‐free (PFS) and overall survival (OS) were estimated using Kaplan–Meier and Cox regression methods (time‐dependent where appropriate)]

    Very high frequency gravitational wave background in the universe

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    Astrophysical sources of high frequency gravitational radiation are considered in association with a new interest to very sensitive HFGW receivers required for the laboratory GW Hertz experiment. A special attention is paid to the phenomenon of primordial black holes evaporation. They act like black body to all kinds of radiation, including gravitons, and, therefore, emit an equilibrium spectrum of gravitons during its evaporation. Limit on the density of high frequency gravitons in the Universe is obtained, and possibilities of their detection are briefly discussed.Comment: 14 page

    Effect of dehydration on the inactivation of Listeria monocytogenes and Salmonella enterica on enoki and wood ear mushrooms

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    Foodborne illness outbreaks in the U.S. associated with consumption of both fresh and dried specialty mushrooms have recently occurred. Dried wood ear mushrooms were implicated in a salmonellosis outbreak in 2020, while fresh enoki mushrooms were associated with two listeriosis outbreaks in 2020 and 2023. These specialty mushrooms are commercially available in both their fresh and dried states. Due to the short shelf life of mushrooms, dehydration is a common method used in both industry and by consumers to extend the shelf life and preserve quality. Therefore, the aim of this study was to evaluate the use of dehydration on the inactivation kinetics of both Listeria monocytogenes and Salmonella enterica on enoki and wood ear mushrooms. Fresh mushrooms were inoculated with four strain cocktails of either L. monocytogenes or S. enterica and dried at ambient conditions for 10 min. Following drying of the inoculum, mushrooms were placed into food dehydrators preheated to 70, 80, or 90°C and treated for up to 24 h. At treatment intervals, mushrooms were removed from the dehydrators for pathogen enumeration. Inactivation kinetics for both pathogens were modeled using the Weibull, log-linear with tail, and log-linear with shoulder models. Pathogen reductions of >4 log CFU/g were achieved on both enoki and wood ear mushrooms during dehydration at 90°C after only 2–4 h. At 70 and 80°C, log reductions of >4 log CFU/g were observed on wood ear mushrooms after 4–8 h. On enoki mushrooms, a tailing effect was observed with residual populations (>2 log CFU/g) of L. monocytogenes and S. enterica remaining even after 24 h of treatment at both 70 and 80°C. This study emphasizes the need for an individualized dehydration strategy for each mushroom type to ensure the effectiveness of dehydration as a process to reduce pathogen populations. Results of this study will aid in informing proper time and temperature combinations for dehydration of specialty mushrooms to ensure product safety

    Marrow-Infiltrating Regulatory T Cells Correlate with the Presence of Dysfunctional CD4⁺PD-1⁺ Cells and Inferior Survival in Patients with Newly Diagnosed Multiple Myeloma

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    PURPOSE: Immune dysregulation is described in multiple myeloma(MM). While preclinical models suggest a role for altered T cell immunity in disease progression, the contribution of immune dysfunction to clinical outcomes remains unclear. We aimed to characterise marrow infiltrating T cells in newly diagnosed patients and explore associations with outcomes of first line therapy. EXPERIMENTAL DESIGN: We undertook detailed characterisation of T cells from bone marrow(BM) samples, focusing on immune checkpoints and features of immune dysfunction, correlating with clinical features and progression free survival. RESULTS: We found that patients with MM had greater abundance of BM regulatory T cells (Tregs) which, in turn, expressed higher levels of the activation marker CD25 compared to healthy donors. Patients with a higher frequencies of Tregs (Treghi) had shorter PFS, and a distinct Treg immune checkpoint profile (increased PD-1, LAG-3) compared to Treglopatients. Analysis of CD4 and CD8 effectors revealed that low CD4effector:Treg ratio, and increased frequency of PD-1 expressing CD4effcells were independent predictors of early relapse over and above conventional risk factors such as genetic risk and depth of response. Ex-vivo functional analysis and RNA sequencing revealed that CD4 and CD8 cells from patients with greater abundance of CD4effPD-1+ cells displayed transcriptional and secretory features of dysfunction. CONCLUSIONS: BM infiltrating T cell subsets, specifically Treg and PD-1 expressing CD4 effectors, negatively influence clinical outcomes in newly diagnosed patients. Pending confirmation in larger cohorts and further mechanistic work, these immune parameters may inform new risk models, and present potential targets for immunotherapeutic strategies
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