Boxfishes (Teleostei: Ostraciidae) as a model system for fishes swimming with many fins: kinematics

Swimming movements in boxfishes were much more complex and varied than classical descriptions indicated. At low to moderate rectilinear swimming speeds (<5 TL s^(-1), where TL is total body length), they were entirely median- and paired-fin swimmers, apparently using their caudal fins for steering. The pectoral and median paired fins generate both the thrust needed for forward motion and the continuously varied, interacting forces required for the maintenance of rectilinearity. It was only at higher swimming speeds (above 5 TL s^(-1)), when burst-and-coast swimming was used, that they became primarily body and caudal-fin swimmers. Despite their unwieldy appearance and often asynchronous fin beats, boxfish swam in a stable manner. Swimming boxfish used three gaits. Fin-beat asymmetry and a relatively nonlinear swimming trajectory characterized the first gait (0–1 TL s^(-1)). The beginning of the second gait (1–3 TL s^(-1)) was characterized by varying fin-beat frequencies and amplitudes as well as synchrony in pectoral fin motions. The remainder of the second gait (3–5 TL s^(-1)) was characterized by constant fin-beat amplitudes, varying finbeat frequencies and increasing pectoral fin-beat asynchrony. The third gait (>5 TL s^(-1)) was characterized by the use of a caudal burst-and-coast variant. Adduction was always faster than abduction in the pectoral fins. There were no measurable refractory periods between successive phases of the fin movement cycles. Dorsal and anal fin movements were synchronized at speeds greater than 2.5 TL s^(-1), but were often out of phase with pectoral fin movements

Density of states determined from Monte Carlo simulations

We describe method for calculating the density of states by combining several canonical monte carlo runs. We discuss how critical properties reveal themselves in $g(\epsilon)$ and demonstrate this by applying the method several different phase transitions. We also demonstrate how this can used to calculate the conformal charge, where the dominating numerical method has traditionally been transfer matrix.Comment: Major revision of paper, several references added throughout. Current version accepted for publication in Phys. Rev.

Conserved Growth on Vicinal Surfaces

A crystal surface which is miscut with respect to a high symmetry plane exhibits steps with a characteristic distance. It is argued that the continuum description of growth on such a surface, when desorption can be neglected, is given by the anisotropic version of the conserved KPZ equation (T. Sun, H. Guo, and M. Grant, Phys. Rev. A 40, 6763 (1989)) with non-conserved noise. A one--loop dynamical renormalization group calculation yields the values of the dynamical exponent and the roughness exponent which are shown to be the same as in the isotropic case. The results presented here should apply in particular to growth under conditions which are typical for molecular beam epitaxy.Comment: 10 pages, uses revte

Hausdorff dimension of critical fluctuations in abelian gauge theories

The geometric properties of the critical fluctuations in abelian gauge theories such as the Ginzburg-Landau model are analyzed in zero background field. Using a dual description, we obtain scaling relations between exponents of geometric and thermodynamic nature. In particular we connect the anomalous scaling dimension $\eta$ of the dual matter field to the Hausdorff dimension $D_H$ of the critical fluctuations, {\it which are fractal objects}. The connection between the values of $\eta$ and $D_H$, and the possibility of having a thermodynamic transition in finite background field, is discussed.Comment: Accepted for publication in PR

Restarting a prisoner's life onto a supportive path leading to RESETtlement in the community: The RESET Study

Executive Summary The potential of not having secure accommodation upon release from prison is a major problem for prisoners with mental health needs. This study focused on evaluating an intervention that supported prisoners upon their release from prison with the primary objective being to support them in finding accommodation release from prison service. In September, 2019 there were 83,518 prisoners detained in England and Wales (Her Majesty’s Prison and Probation Service, 2019). The period of transition from prison to the community has been acknowledged as a confusing and chaotic experience for many which is intensified by being homeless. A recent survey ascertained that 36% of people found rough sleeping had previously been in prison (CHAIN, 2018). Being homeless is viewed as a major factor in the likelihood of reoffending (Homeless Link, 2018) and not engaging with support services (health services, GP services, welfare benefits) (Williamson, 2007). It has been estimated that over 90% of prisoners have one or more psychiatric disorders (psychosis, neurosis, personality disorder, hazardous drinking and drug dependency). The period directly before and following release from prison is a highly stressful and isolating experience that exacerbates mental health problems (Theurer & Lovell, 2008; The Mental Welfare Commission for Scotland, 2017). Hopkins & Thornicroft (2014) have also reported that prisoners with mental health problems have twenty-nine times the rate of all-cause mortality during the first two weeks after release compared to the general population and are 8.3 times more likely to commit suicide in the twelve months following release from prison compared to the general population. Hancock et al (2018) has proposed that secure housing is the most important factor in ensuring a positive transition from prison to the community for people with mental health problems due to: • It is impossible to address mental health support and treatment before a person has stable accommodation • without housing they are lost to care. If someone does not have a fixed address, they are difficult to locate and connect with which makes it hard to provide support • housing helps break a cycle of returning to poor previous relationships and routines Providing support for prisoners with mental health needs upon their release has the potential to be an important factor in helping reintegrate this cohort into the community through helping to find secure accommodation, improving health and wellbeing, engaging with services, re-establishing contacts with family and friends and reducing reoffending. The Bradley Report (2009) noted if prisoners receive the support they need inside prisons, they were more likely to engage with services outside prison. The report added for the resettlement of prisoners with mental health needs into the community to be successful, it was important to ensure that the engagement that had started in prisons continued once prisoners leave the prison gate. However, the evidence for the effectiveness of existing services approaches is limited. Hopkin et al (2018) undertook a systematic review examining interventions for prisoners with diagnosed mental health conditions that targeted the transition period between prison and the community. Thirteen studies were found (with only two in the UK). The conclusions drawn were that there was some evidence that the interventions examined could improve contact between service users and mental health and other services. However, evidence that it reduced reoffending was equivocal and none on of the studies had examined whether the intervention improved access to secure accommodation. During the period of the study, the standard care package offered to prisoners upon their release was based on the government’s Transforming Rehabilitation strategy aimed to reduce reoffending and to provide a seamless transition between prison and the community by developing “Through the Gate” services (Ministry of Justice, 2013). The Through the Gate service was delivered by the newly commissioned local Community Rehabilitation Companies (CRCs) to help prisoners maintain or find accommodation; aid with finance, benefits and debt; and to support them to enter education, training and employment. It has been noted that prisoners with mental health needs present different challenges, have multiple and complex needs and require a more focused approach than the support provided by the CRCs. In addition, limitations in the amount of support and assistance offered to prisoners with mental health needs and, in particular, the lack of planning and arrangements for suitable accommodation were identified by Her Majesty’s Inspectorate of Probation reports (HMIP, 2019). To provide intensive support to those who had offended but also have identified mental health needs, Oxleas NHS Foundation Trust commissioned Clarion Housing (at the time known as Centra) and Nacro to provide a resettlement service for prisoners with mental health needs upon their release; the Supporting Prisoners upon Release Service (RESET) Intervention service. Clarion Housing worked from HMP Elmley, HMP Rochester and HMP Stamford Hill, while Nacro and Clarion Housing operated in London from HMP ISIS, HMP Belmarsh and HMP Thameside. The threshold for meeting the criteria for receiving support was that service users must have had limited community support in place, high rates of reoffending, and meet at least step 3 on the Oxleas stepped care model. The RESET service was based on the principles of the Critical Time Intervention (CTI) approach. CTI is a structured, time limited intervention developed in the USA in the 1990s to prevent recurrent homelessness in transient individuals with severe and mental illness moving from hospital care into the community. In CTI, case managers provided support for up to nine months to strengthen times with family, friends and service providers and to provide practical and emotional support during the transition in to the community. Studies had found significantly reduced number of homelessness for those users receiving CTI (Susser et al, 1997). The main elements of the RESET service were: • A short-term (12 week) support service to prisoners with an identified level of mental health need • The focus was in obtaining appropriate safe and secure accommodation, access to welfare benefits, re-engagement with health services and strengthening links with family and community support services • Referrals to the service were made through the Mental Health Inreach team at each prison • Work began before release to develop rapport with service user, to try to secure accommodation, and start to fill out necessary paperwork • On the day of release, the support co-ordinator would meet the service user at the gate • The main aim in first day is to ensure the individual has some form of housing • Any released prisoner would be escorted to all crucial appointments on the day, such as probation and local authority housing • Support was provided to ensure that the service users had all the essentials for the first few days i.e. correct medication, scripts and planned appointments • The support co-ordinator worked intensively during the first week of service users release and then gradually reduced their level of contact The overall aim of this study was to evaluate the impact of the RESET service. The specified objectives were to examine the: • Participants’ housing situation • Rate of reoffending • Number of hospital admissions • Number on maintained benefits • Number of contacts with mental health and GP services • Level of engagement with services • Number in employment or education • The service user’s views of the RESET servic

Multiplicity Distributions and Rapidity Gaps

I examine the phenomenology of particle multiplicity distributions, with special emphasis on the low multiplicities that are a background in the study of rapidity gaps. In particular, I analyze the multiplicity distribution in a rapidity interval between two jets, using the HERWIG QCD simulation with some necessary modifications. The distribution is not of the negative binomial form, and displays an anomalous enhancement at zero multiplicity. Some useful mathematical tools for working with multiplicity distributions are presented. It is demonstrated that ignoring particles with pt<0.2 has theoretical advantages, in addition to being convenient experimentally.Comment: 24 pages, LaTeX, MSUHEP/94071

Effect of bonding of a CO molecule on the conductance of atomic metal wires

We have measured the effect of bonding of a CO molecule on the conductance of Au, Cu, Pt, and Ni atomic contacts at 4.2 K. When CO gas is admitted to the metal nano contacts, a conductance feature appears in the conductance histogram near 0.5 of the quantum unit of conductance, for all metals. For Au, the intensity of this fractional conductance feature can be tuned with the bias voltage, and it disappears at high bias voltage (above $\sim$ 200 mV). The bonding of CO to Au appears to be weakest, and associated with monotomic Au wire formation.Comment: 6 figure

Manifestation of quantum chaos on scattering techniques: application to low-energy and photo-electron diffraction intensities

Intensities of LEED and PED are analyzed from a statistical point of view. The probability distribution is compared with a Porter-Thomas law, characteristic of a chaotic quantum system. The agreement obtained is understood in terms of analogies between simple models and Berry's conjecture for a typical wavefunction of a chaotic system. The consequences of this behaviour on surface structural analysis are qualitatively discussed by looking at the behaviour of standard correlation factors.Comment: 5 pages, 4 postscript figures, Latex, APS, http://www.icmm.csic.es/Pandres/pedro.ht

Detection, Properties, and Frequency of Local Calcium Release from the Sarcoplasmic Reticulum in Teleost Cardiomyocytes

Calcium release from the sarcoplasmic reticulum (SR) plays a central role in the regulation of cardiac contraction and rhythm in mammals and humans but its role is controversial in teleosts. Since the zebrafish is an emerging model for studies of cardiovascular function and regeneration we here sought to determine if basic features of SR calcium release are phylogenetically conserved. Confocal calcium imaging was used to detect spontaneous calcium release (calcium sparks and waves) from the SR. Calcium sparks were detected in 16 of 38 trout atrial myocytes and 6 of 15 ventricular cells. The spark amplitude was 1.45±0.03 times the baseline fluorescence and the time to half maximal decay of sparks was 27±3 ms. Spark frequency was 0.88 sparks µm−1 min−1 while calcium waves were 8.5 times less frequent. Inhibition of SR calcium uptake reduced the calcium transient (F/F0) from 1.77±0.17 to 1.12±0.18 (p = 0.002) and abolished calcium sparks and waves. Moreover, elevation of extracellular calcium from 2 to 10 mM promoted early and delayed afterdepolarizations (from 0.6±0.3 min−1 to 8.1±2.0 min−1, p = 0.001), demonstrating the ability of SR calcium release to induce afterdepolarizations in the trout heart. Calcium sparks of similar width and duration were also observed in zebrafish ventricular myocytes. In conclusion, this is the first study to consistently report calcium sparks in teleosts and demonstrate that the basic features of calcium release through the ryanodine receptor are conserved, suggesting that teleost cardiac myocytes is a relevant model to study the functional impact of abnormal SR function

A theorem on the absence of phase transitions in one-dimensional growth models with onsite periodic potentials

We rigorously prove that a wide class of one-dimensional growth models with onsite periodic potential, such as the discrete sine-Gordon model, have no phase transition at any temperature $T>0$. The proof relies on the spectral analysis of the transfer operator associated to the models. We show that this operator is Hilbert-Schmidt and that its maximum eigenvalue is an analytic function of temperature.Comment: 6 pages, no figures, submitted to J Phys A: Math Ge