Explore the vast range of titles available.

The highly infectious and pathogenic novel coronavirus (CoV), severe acute respiratory syndrome (SARS)-CoV-2, has emerged causing a global pandemic. Although COVID-19 predominantly affects the respiratory system, evidence indicates a multisystem disease which is frequently severe and often results in death. Long-term sequelae of COVID-19 are unknown, but evidence from previous CoV outbreaks demonstrates impaired pulmonary and physical function, reduced quality of life and emotional distress. Many COVID-19 survivors who require critical care may develop psychological, physical and cognitive impairments. There is a clear need for guidance on the rehabilitation of COVID-19 survivors. This consensus statement was developed by an expert panel in the fields of rehabilitation, sport and exercise medicine (SEM), rheumatology, psychiatry, general practice, psychology and specialist pain, working at the Defence Medical Rehabilitation Centre, Stanford Hall, UK. Seven teams appraised evidence for the following domains relating to COVID-19 rehabilitation requirements: pulmonary, cardiac, SEM, psychological, musculoskeletal, neurorehabilitation and general medical. A chair combined recommendations generated within teams. A writing committee prepared the consensus statement in accordance with the appraisal of guidelines research and evaluation criteria, grading all recommendations with levels of evidence. Authors scored their level of agreement with each recommendation on a scale of 0–10. Substantial agreement (range 7.5–10) was reached for 36 recommendations following a chaired agreement meeting that was attended by all authors. This consensus statement provides an overarching framework assimilating evidence and likely requirements of multidisciplinary rehabilitation post COVID-19 illness, for a target population of active individuals, including military personnel and athletes.

To date, few studies have evaluated sub-organismal responses (e.g., physiological or energetic consequences) of individual fish to hydropower infrastructure (e.g., fishways, turbines) or operations (e.g., fluctuating flows, low flows). The field of “conservation physiology” (i.e., the use of physiological information to enhance conservation) is expanding rapidly and has great promise for hydropower research. However, there is a need to both expand the “toolbox” available to practitioners and to validate these tools for use in this context. This synthetic report details the behavioural, energetic, genomic, molecular, forensic, isotopic, and physiological tools available for studying sub-organismal responses of fish to hydropower infrastructure and operating procedures with a critical assessment of their benefits and limitations. Furthermore, this paper provides two case studies where behavioural, energetic, and physiological tools have been used in hydropower settings. Progressive and interdisciplinary approaches to hydropower research are needed to advance the science of sustainable river regulation and hydropower development. The expanded toolbox could be used by practitioners to assess fishway performance, migration delays, and fish responses to fluctuating flows through a more mechanistic approach than can be offered by only focusing on population metrics or indices of community structure. These tools are also relevant for the evaluation of other anthropogenic impacts such as water withdrawal for irrigation or drinking water, habitat alteration, and fisheries interactions.

Black-bellied wrens (Thryothorus fasciatoventris) use loud songs to communicate sex over long distances. We compared male and female songs recorded from a central Panamanian population of black-bellied wrens. All nine measured features differed significantly between the sexes. Males sang lower fundamental frequencies than females, but this difference cannot be explained by simple body size-frequency scaling. A discriminant function analysis correctly discriminated the singer's sex for all songs in the analysis. When viewed as sonograms, the terminal syllables of male and female songs exhibited opposite structure - all male songs ended in V-shaped syllables, and all female songs ended in arc-shaped syllables. The degree and character of dimorphism lead us to describe song structure in this population as 'sexually antithetical'. Variation in song dimorphism throughout this species' range provides an excellent opportunity to test the hypothesis that signal degradation during transmission selects for divergent signal structure.

Background Chronic Exertional Compartment Syndrome (CECS) presents as exertional pain in the lower limb presumed to be a result of elevated intramuscular compartment pressure (IMCP) although this has never been proven. Doubt exists regarding the validity of the diagnostic criteria for CECS, the role of IMCP and the outcomes from surgical management. An alternative biomechanical condition, Anterior Biomechanical Overload Syndrome (ABOS), was proposed to account for the symptoms of CECS and a programme of gait re-education (GRE) was introduced although no primary research has been carried out to investigate the predisposing biomechanical and anthropometric factors for CECS. Methods Case-control studies investigated the anthropometric, biomechanical and IMCP differences between CECS cases and asymptomatic controls. A post-surgical study evaluated the role of IMCP and a longitudinal study investigated the effectiveness of GRE and the nature of resultant biomechanical changes. Results Cases were significantly shorter than controls with increased plantarflexion at toe off and an increased rate of plantarflexion after heel strike. IMCP levels were significantly higher in cases than controls allowing for the extraction of diagnostic criteria for CECS. Surgical responders had similar IMCP to controls but significantly lower IMCP than non-responders. The biomechanical symptoms of ABOS were not replicated. GRE made changes to gait but these did not correspond to those identified in the CECS case-control study. Conclusions The intrinsic role of IMCP in CECS has been confirmed allowing for improved diagnostic criteria. Use of these criteria should allow for improved patient selection for surgery and improved outcomes for CECS. Novel insights to the biomechanical and anthropometric differences are provided allowing for the proposal of a new pathophysiological model whereby extrinsic training conditions impact upon intrinsic risk factors leading to CECS. These studies do not support the existence of ABOS or the use of GRE in the management of CECS.

The various successes of Milgrom's MOND have led to suggestions that its critical acceleration parameter \\(a_0 \\approx 1.2\\times 10^{-10}\\,mtrs/sec^2\\) is a fundamental physical constant in the same category as the gravitational constant (for example), and therefore requiring no further explanation. There is no independent evidence supporting this conjecture. Motivated by empirical indications of self-similarities on the exterior part of the optical disk (the optical annulus), we describe a statistical analysis of four large samples of optical rotation curves and find that quantitative indicators of self-similar dynamics on the optical annulus are irreducibly present in each of the samples. These symmetries lead to the unambiguous identification of a characteristic point, \\((R_c,V_c)\\), on each annular rotation curve where \\(R_c \\approx f(M,S)\\) and \\(V_c \\approx g(M)\\) for absolute magnitude \\(M\\) and surface brightness \\(S\\). This opens the door to an investigation of the behaviour of the associated characteristic acceleration \\(a_c \\equiv V_c^2/R_c\\) across each sample. The first observation is that since \\(a_c \\approx g^2(M)/f(M,S)\\), then \\(a_c\\) is a constant within any given disk, but varies between disks. Calculation then shows that \\(a_c\\) varies in the approximate range \\((1.2\\pm0.5)\\times 10^{-10}\\,mtrs/sec^2\\) for each sample. It follows that Milgrom's \\(a_0\\) is effectively identical to \\(a_c\\), and his critical acceleration boundary is actually the characteristic boundary, \\(R=R_c\\), on any given disk. Since \\(a_c\\) varies between galaxies, then so must \\(a_0\\) also. In summary,Milgrom's critical acceleration boundary is an objective characteristic of the optical disk and \\(a_0\\) cannot be a fundamental physical constant.

It has recently been reported that the application of convolutional neural-network techniques to infer the dark-matter distribution in the local cosmos has revealed how it follows the \\(D\\approx 2\\) hierarchical distribution of galaxies in the locality, rather than exhibiting the expected homogeneity throughout the IGM. Taken at face value, this implies that the Hubble Law, observed to be followed on scales which are deep inside the observed hierarchical structures, can no longer be assumed to arise from universal expansion. So, if not universal expansion, then what? As a possibility, it has been recognized for a considerable time that if the lower cut-off scales of a \\(D \\approx 2\\) hierarchical cosmos are identified with the scales of a typical galaxy, then gravitational redshift automatically follows the Hubble Law with \\(H_g \\approx 70\\,km/sec/Mpc\\). Inter alia, this suggests a model of galaxy formation in a \\(D\\approx2\\) hierarchical IGM in which all of the material \\(M_0\\) within a sphere \\(R_0\\) coalesces about a unique center so that hierarchical symmetry is broken on the scale \\((M_0,R_0)\\). Putting these things together leads unambiguously to the conclusion that, in an hierachical cosmos, the Dark Matter hypothesis and Milgrom's MOND hypothesis are two sides of the same coin.

It has been reported that the application of convolutional neural-network techniques to infer the Dark Matter distribution in the local IGM has revealed how it follows the hierarchical distribution of galaxies in the locality, rather than exhibiting homogeneity. This result makes it natural to consider the possibility that, on scales at least as big as \\(20 \\sim 30\\,Mpc\\), the distribution of all material comprising the local IGM is hierarchically distributed. Given this possibility, any model of galaxy formation must then involve a process in which all of the hierarchically distributed material \\(M_0\\) within a sphere \\(R_0\\) coalesces about a unique center so that hierarchical symmetry is broken on the scale \\((M_0,R_0)\\). In the particular case of the hierarchical distribution being quasi-fractal \\(D \\approx 2\\) in the local cosmos then, for circular velocity \\(V_0\\) on \\(R_0\\), the scaling relation \\(V_0^4 \\sim M_0\\) emerges automatically when the condition that such a galaxy formation process must be gravitationally stable in the Newtonian sense is applied. In other words, subject to the caveat that the analysis applies to a highly idealized model, the Baryonic Tully-Fisher Relationship (BTFR) is shown to arise as a consequence of Newtonian gravitation acting in a hierarchical Universe. We discuss the ramifications of this result, which are significant and non-trivial.

BackgroundPatients with chronic exertional compartment syndrome (CECS) have pain during exercise that usually subsides at rest. Diagnosis is usually confirmed by measurement of intramuscular compartment pressure (IMCP) following exclusion of other possible causes. Management usually requires fasciotomy but reported outcomes vary widely. There is little evidence of the effectiveness of fasciotomy on IMCP. Testing is rarely repeated postoperatively and reported follow-up is poor. Improved diagnostic criteria based on preselection and IMCP levels during dynamic exercise testing have recently been reported.Objectives(1) To compare IMCP in three groups, one with classical symptoms and no treatment and the other with symptoms of CECS who have been treated with fasciotomy and an asymptomatic control group. (2) Establish if differences in IMCP in these groups as a result of fasciotomy relate to functional and symptomatic improvement.MethodsTwenty subjects with symptoms of CECS of the anterior compartment, 20 asymptomatic controls and 20 patients who had undergone fasciotomy for CECS were compared. All other possible diagnoses were excluded using rigorous inclusion criteria and MRI. Dynamic IMCP was measured using an electronic catheter wire before, during and after participants exercised on a treadmill during a standardised 15 min exercise challenge. Statistical analysis included t-tests and analysis of variance.ResultsFasciotomy results in reduced IMCP at all time points during a standardised exercise protocol compared with preoperative cases. In subjects responding to fasciotomy, there is a significant reduction in IMCP below that of preoperative groups (P<0.001). Postoperative responders to fasciotomy have no significant differences in IMCP from asymptomatic controls (P=0.182).ConclusionFasciotomy reduces IMCP in all patients. Larger studies are required to confirm that the reduction in IMCP accounts for differences in functional outcomes and pain reductions seen in postoperative patients with CECS.

The irrefutable successes of MOND are predicated upon the idea that a critical gravitational acceleration scale, \\(a_0\\), exists. But, beyond its role in MOND, the question: 'Why should a critical gravitational acceleration scale exist at all?' remains unanswered. There is no deep understanding about what is going on. Over roughly the same period that MOND has been a topic of controversy, Baryshev, Sylos Labini, Pietronero and others have been arguing, with equal controversy in earlier years, that, on medium scales at least, material in the universe is distributed in a quasi-fractal \\(D\\approx 2\\) fashion. There is a link: if the idea of a quasi-fractal \\(D \\approx 2\\) universe on medium scales is taken seriously then there is an associated characteristic mass surface density scale, \\(\\Sigma_F\\) say, and an associated characteristic gravitational acceleration scale, \\(a_F = 4 \\pi G \\Sigma_F\\). If, furthermore, the quasi-fractal structure is taken to include the inter-galactic medium, then it is an obvious step to consider the possibility that \\(a_0\\) and \\(a_F\\) are the same thing. Subsequently, via a modern geometric realization of the Leibniz-Mach worldview, we obtain a detailed theoretical understanding of how galaxy disks should interact with a \\(D\\approx 2\\) quasi-fractal IGM. This understanding takes the form of a superficially unremarkable scaling relationship which, used with standard photometric mass-modelling applied to SPARC data, shows that \\(a_F \\approx 1.2\\times 10^{-10}\\, mtrs/sec^2\\) is explicitly embedded in that data. Since the scaling relationship also gives rise to the Baryonic Tully-Fisher Relationship, but with \\(a_0\\) replaced by \\(a_F\\), we are led unambiguously to the conclusion that \\(a_0\\) and \\(a_F\\) are, in reality, one and the same thing.

The SPARC sample consists of 175 nearby galaxies with modern surface photometry at \\(3.6\\,\\mu m\\) and high quality rotation curves. The sample has been constructed to span very wide ranges in surface brightness, luminosity, rotation velocity and Hubble type, thereby forming a representative sample on galaxies in the nearby Universe. To date, the SPARC sample is the largest collection of galaxies with both high-quality rotation curves and NIR surface photometry. The neo-MOND model used here to analyse the SPARC sample recognizably conforms to the general pattern of the classical MOND algorithm, with the primary difference that, whereas the classical MOND model is purely phenomonological, the neo-MOND model is a special case of a general theory motivated by the ideas of Leibniz and Mach (not discussed here). The consequent main results can be broadly summarized as follows: (1) neo-MOND provides the basis for the derivation of a complete theory of the baryonic Tully-Fisher relation; (2) the details of the derivation provide a means of setting absolute distance scales for disc galaxies independently of standard candles and the photometric method; (3) subsequent determinations of dynamical mass (computed directly from neo-MOND fits to SPARC rotation curves) track photometric mass (estimated from SPARC surface photometry) across the whole SPARC sample in a statistically perfect way. To summarize, if the input to neo-MOND is disk dynamical data, then the output is whole-disk mass data together with absolute distance scales.