Radiation from a Charge Uniformly Accelerated for All Time

A recent paper of Singal [Gen. Rel. Grav. 27 (1995), 953-967] argues that a uniformly accelerated particle does not radiate, in contradiction to the consensus of the research literature over the past 30 years. This note points out some questionable aspects of Singal's argument and shows how similar calculations can lead to the opposite conclusion.Comment: LaTeX, 9 pages, to appear in General Relativity and Gravitatio

Targeted genome modifications in soybean with CRISPR/Cas9

Background: The ability to selectively alter genomic DNA sequences in vivo is a powerful tool for basic and applied research. The CRISPR/Cas9 system precisely mutates DNA sequences in a number of organisms. Here, the CRISPR/Cas9 system is shown to be effective in soybean by knocking-out a green fluorescent protein (GFP) transgene and modifying nine endogenous loci. Results: Targeted DNA mutations were detected in 95% of 88 hairy-root transgenic events analyzed. Bi-allelic mutations were detected in events transformed with eight of the nine targeting vectors. Small deletions were the most common type of mutation produced, although SNPs and short insertions were also observed. Homoeologous genes were successfully targeted singly and together, demonstrating that CRISPR/Cas9 can both selectively, and generally, target members of gene families. Somatic embryo cultures were also modified to enable the production of plants with heritable mutations, with the frequency of DNA modifications increasing with culture time. A novel cloning strategy and vector system based on In-Fusion (R) cloning was developed to simplify the production of CRISPR/Cas9 targeting vectors, which should be applicable for targeting any gene in any organism. Conclusions: The CRISPR/Cas9 is a simple, efficient, and highly specific genome editing tool in soybean. Although some vectors are more efficient than others, it is possible to edit duplicated genes relatively easily. The vectors and methods developed here will be useful for the application of CRISPR/Cas9 to soybean and other plant species

Expression and Action of Kit Ligand/Stem Cell Factor in Normal Human and Bovine Ovarian Surface Epithelium and Ovarian Cancer

Greater than 95% of ovarian cancers originate from the epithelial cells on the surface of the ovary termed ovarian surface epithelium (OSE). A normal aspect of OSE function is repeated proliferation after ovulation, and this is postulated to be involved in part in the onset of ovarian cancer. The hypothesis tested is that locally produced growth factors have an important role in controlling OSE proliferation. The current study investigates the potential role of the growth factor kit ligand (KL)/stem cell growth factor and its receptor c-kit in normal OSE biology and ovarian cancer. Human tumors from borderline, stage I, and stage III cases of ovarian cancer were found to express KL and c-kit protein in the epithelial cell component by ICC analysis. The stromal cell component of human ovarian tumors contained little immunostaining. Bovine ovarian physiology and endocrinology are similar to the human such that cow ovaries were used as a model system to investigate normal OSE functions. KL and c-kit proteins were detected in the OSE from both normal human and bovine ovaries. Adjacent ovarian stromal tissue contained less intense but positive KL and c-kit immunostaining. To extend the ICC results, RNA was collected from normal bovine OSE and ovarian stromal cells to examine KL gene expression. KL transcripts were detected in cultured OSE and stromal cells by Northern blot analysis. KL gene expression was found to be high in freshly isolated OSE but low in freshly isolated stroma using a quantitative polymerase chain reaction procedure. Levels of KL gene expression in cultured OSE and stroma increased to high levels. Observations indicate that normal OSE expresses high levels of KL in vivo and in vitro. The actions of KL on the growth of both normal OSE cells and ovarian cancer cells was investigated. KL was found to stimulate the growth of normal OSE cells in a similar manner to epidermal growth factor. Observations demonstrate the production and action of KL by normal OSE cells and ovarian cancer cells. Coexpression of KL and c-kit by normal OSE suggests that KL can act as an autocrine factor for OSE. The local production and action of KL on OSE provides insight into normal OSE biology, and a factor that may be involved in the onset and progression of ovarian cancer

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

Revivals of quantum wave-packets in graphene

We investigate the propagation of wave-packets on graphene in a perpendicular magnetic field and the appearance of collapses and revivals in the time-evolution of an initially localised wave-packet. The wave-packet evolution in graphene differs drastically from the one in an electron gas and shows a rich revival structure similar to the dynamics of highly excited Rydberg states. We present a novel numerical wave-packet propagation scheme in order to solve the effective single-particle Dirac-Hamiltonian of graphene and show how the collapse and revival dynamics is affected by the presence of disorder. Our effective numerical method is of general interest for the solution of the Dirac equation in the presence of potentials and magnetic fields.Comment: 22 pages, 10 figures, 3 movies, to appear in New Journal of Physic

Lattice thermal conductivity of freestanding gallium nitride nanowires

aip Publishers Publications Topics | Librarians Authors Your access is provided by: Eastern Illinois University Register to create your user account, or sign in if you have an existing account Additional sign in Sign in via Shibboleth/Athens My cart Export citations Add to my favorites Recommend to library Subscribe to email alerts Submit an article Reprints & Permissions Subscribe to RSS Access Key Free Content Open Access Content Subscribed Content Free Trial Content Home \u3e Publishers \u3e AIP Publishing \u3e Journal of Applied Physics \u3e Volume 108, Issue 3 \u3e Article banner image F Lattice thermal conductivity of freestanding gallium nitride nanowires Download PDF Jie Zou1,a) + View Affiliations a) Electronic mail: [email protected]. J. Appl. Phys. 108, 034324 (2010); http://dx.doi.org/10.1063/1.3463358 Previous Article Table of Contents Next Article Back to Search Results facebook twitter Share this page separator email print this page Abstract Full Text References (28) Cited By (8) Data & Media Metrics Related We report detailed calculations of the lattice thermal conductivity of freestanding gallium nitride(GaN)nanowires with diameters ranging from 20 to 140 nm. Results are compared with experimental data on GaNnanowires grown by thermal chemical vapor deposition(CVD). Calculations are based on the Boltzmann transport equation and take into account the change in the nonequilibrium phonon distribution in the case of diffuse scattering at the surfaces. Phonon dispersion relation is obtained in the elastic continuum approximation for each given nanowire. For valid comparisons with the experimental data, simulations are performed with a dopant concentration and impurity profile characteristic of thermal CVDGaNnanowires. Our results show that the room-temperature thermal conductivity of the nanowires has very low values, ranging from 6.74 W/m K at 20 nm to 16.4 W/m K at 140 nm. The obtained results are in excellent agreement with the experimental data. We have also demonstrated that in addition to impurity scattering, boundary scattering, and phonon confinement, the change in the nonequilibrium phonon distribution leads to a further reduction in the thermal conductivity of the nanowires and has to be taken into account in the calculations. Our conclusion is different from that of an earlier study which attributed the very low thermal conductivity to the unusually large mass-difference scattering in the nanowires

The AMSC mobile satellite system

The American Mobile Satellite Consortium (AMSC) Mobile Satellite Service (MSS) system is described. AMSC will use three multi-beam satellites to provide L-band MSS coverage to the United States, Canada and Mexico. The AMSC MSS system will have several noteworthy features, including a priority assignment processor that will ensure preemptive access to emergency services, a flexible SCPC channel scheme that will support a wide diversity of services, enlarged system capacity through frequency and orbit reuse, and high effective satellite transmitted power. Each AMSC satellite will make use of 14 MHz (bi-directional) of L-band spectrum. The Ku-band will be used for feeder links

Mobile satellite service in the United States

Mobile satellite service (MSS) has been under development in the United States for more than two decades. The service will soon be provided on a commercial basis by a consortium of eight U.S. companies called the American Mobile Satellite Consortium (AMSC). AMSC will build a three-satellite MSS system that will offer superior performance, reliability and cost effectiveness for organizations requiring mobile communications across the U.S. The development and operation of MSS in North America is being coordinated with Telesat Canada and Mexico. AMSC expects NASA to provide launch services in exchange for capacity on the first AMSC satellite for MSAT-X activities and for government demonstrations

Applications of graphics to support a testbed for autonomous space vehicle operations

Researchers describe their experience using graphics tools and utilities while building an application, AUTOPS, that uses a graphical Machintosh (TM)-like interface for the input and display of data, and animation graphics to enhance the presentation of results of autonomous space vehicle operations simulations. AUTOPS is a test bed for evaluating decisions for intelligent control systems for autonomous vehicles. Decisions made by an intelligent control system, e.g., a revised mission plan, might be displayed to the user in textual format or he can witness the effects of those decisions via out of window graphics animations. Although a textual description conveys essentials, a graphics animation conveys the replanning results in a more convincing way. Similarily, iconic and menu-driven screen interfaces provide the user with more meaningful options and displays. Presented here are experiences with the SunView and TAE Plus graphics tools used for interface design, and the Johnson Space Center Interactive Graphics Laboratory animation graphics tools used for generating out out of the window graphics