GANIL RF systems : feedback control system and electronics

http://accelconf.web.cern.ch/AccelConf/c81/papers/ep-10.pdfInternational audienc

Quantum Kinetic Rates within the Nonequilibrium Steady State

The nonequilibrium steady state (NESS) of a quantum network is central to a host of physical and biological scenarios. Examples include natural processes such as vision and photosynthesis, as well as technical devices such as photocells, both activated by incoherent light (e.g. sunlight) and leading to quantum transport. Here, a completely general approach to defining components of a quantum network in the NESS, and obtaining rates of processes between these components is provided. Quantum effects are explicitly included throughout, both in (a) defining network components via projection operators, and (b) in determining the role of coherences in rate processes. As examples, the methodology is applied to model cases, two versions of the V-level system, and to the spin-boson model, wherein the role of the environment and of internal system properties in determining the rates is examined. In addition, the role of Markovian vs. non-Markovian contributions is quantified, exposing conditions under which NESS rates can be obtained by perturbing the nonequilibrium steady state

Critical care triage during the COVID-19 pandemic in South Africa: A constitutional imperative!

Triage and rationing of scarce intensive care unit (ICU) resources are an unavoidable necessity. In routine circumstances, ICU triage is premised on the best interests of an individual patient; however, when increased demand exceeds capacity, as during an infectious disease outbreak, healthcare providers need to make difficult decisions to benefit the broader community while still respecting individual interests. We are currently living through an unprecedented period, with South Africa (SA) facing the challenges of the global COVID-19 pandemic. The Critical Care Society of Southern Africa (CCSSA) expedited the development of a triage guidance document to inform the appropriate and fair use of scarce ICU resources during this pandemic. Triage decision-making is based on the clinical odds of a positive ICU outcome, balanced against the risk of mortality and longer-term morbidity affecting quality of life. Factors such as age and comorbid conditions are considered for their potential impact on clinical outcome, but are never the sole criteria for denying ICU-level care. Arbitrary, unfair discrimination is never condoned. The CCSSA COVID-19 triage guideline is aligned with SA law and international ethical standards, and upholds respect for all persons. The Bill of Rights, however, does not mandate the level of care enshrined in the constitutional right to healthcare. ICU admission is not always appropriate, available or feasible for every person suffering critical illness or injury; however, everyone has the right to receive appropriate healthcare at another level. If ICU resources are used for people who do not stand to benefit, this effectively denies others access to potentially life-saving healthcare. Appropriate triaging can therefore be considered a constitutional imperative

The SISSI project : an intense secondary ion source using superconducting solenoid lenses

International audienceIn order to make a better use of the higher beam intensities soon available at GANIL, a proposal called SISSI was presented in 1989. It consists of a set of two superconducting solenoid lenses of very short focal length (0.6 m). The fist solenoid is used to sharply focus the incoming beam on a fast moving target. The second increases the angular acceptance of the beam line downstream the target for charged reaction products. Calculations show that from a 0.4-mm-diameter beam spot on the target, an acceptance angle of up to 80 mrad will be reached without significant emittance growth due to aberration effects. Technical aspects of that project are presente

Superconducting booster cyclotron studies at GANIL

International audienc

An examination of semantic impairment in amnestic MCI and AD : What can we learn from verbal fluency?

Introduction The Verbal Fluency Test (VF) is commonly used in neuropsychology. Some studies have demonstrated a marked impairment of semantic VF compared to phonemic VF in Alzheimer’s disease (AD). Since amnestic Mild Cognitive Impairment (aMCI) is associated with increased risk of conversion to incident AD, it is relevant to examine whether a similar impairment is observed in this population. The objective of the present empirical study is to compare VF performance of aMCI patients to those of AD and elderly controls matched one-to-one for age and education. Method Ninety-six participants divided into three equal groups (N = 32: AD, aMCI and Controls) were included in this study. Participants in each group were, on average, 76 years of age and had 13 years of education. A repeated measures ANOVA with the Group (AD, aMCI, NC) as between-subject factor and the Fluency condition (“P” and “animals”) as within-subject factor was performed. T-tests and simple ANOVAs were also conducted to examine the interaction. Results There was a significant interaction between the groups and the verbal fluency condition. In AD, significantly fewer words were produced in both conditions. In contrast, participants with aMCI demonstrated a pattern similar to controls in the phonemic condition, but generated significantly fewer words in the semantic condition. Conclusion These results indicate a semantic memory impairment in aMCI revealed by a simple, commonly-used neuropsychological test. Future studies are needed to investigate if semantic fluency deficits can help predict future conversion to AD

Trends in pharmacotherapy selection for the treatment of alcohol withdrawal in the Free State Province, South Africa

Background.The selection of pharmacotherapy for the treatment of alcohol withdrawal remains a clinical challenge. Research continues into the underlying pathophysiology of dependence and withdrawal. A spectrum of clinical presentations of alcohol dependence is emerging, yet recommendations and guidelines have remained unchanged for some time.  Objectives. To engage with the problem of translating research into practice, as reflected by the selection of pharmacotherapy for alcohol withdrawal by medical practitioners in the Free State Province, South Africa. Methods. A questionnaire-based survey and interviews were conducted among 121 professionals in both the private and public sectors across the province. A subgroup was formed comprising the 58 doctors who indicated that they prescribe for alcohol withdrawal. Participants worked in private general practice, specialist psychiatry practice, in a state hospital or in a treatment centre. Results. Prescribing practices varied based on practitioners’ geographical distribution and professional capacity. Deviation from standard recommendations included the routine use of clothiapine and antidepressants in withdrawal regimens. Prescribing clothiapine appears to be a local custom. While prescription of antidepressants may indicate unrealistic expectations of therapeutic benefit, there are clear indications that this is maintained to mask the diagnosis of an alcohol-related condition. Prescribing for alcohol withdrawal is therefore not necessarily determined by pathophysiology or efficacy of medication. Conclusion. Withdrawal regimens need to be reassessed by researchers, policy makers and funders, balancing new developments with the real-life experiences and challenges of prescribers and their patients

Help-seeking by substance dependants presenting to healthcare professionals in the Free State Province

Introduction. Current data regarding treatment needs in South Africa for substance dependence are based on admissions to specialised treatment centres. The data therefore do not include patients presenting to independent healthcare workers and state hospitals. Aim. The aim of this study was to investigate help-seeking behaviour for substance dependence disorders from the perspective of healthcare professionals at various levels of the referral chain in Free State Province. Design. A descriptive study was performed. Setting. Treatment environments in Free State Province accessible to substance-dependent persons. Participants. General practitioners, private psychiatrists, prescribing healthcare professionals at state hospitals and treatment centres, and non-prescribing therapists responsible for management of substance-dependent persons. Measurements. A questionnaire was used to determine the level of help-seeking experienced by the participants regarding various classes of psycho-active substances. Findings. The presentation of alcohol, cannabis, opioid, benzodiazepine, ecstasy, cocaine and inhalant dependency at general practitioners, private psychiatrists, treatment centres and non-prescribing therapists was compared. Different patterns of help-seeking for substance dependence from the various professional groups were detected. Regarding alcohol dependence, 40.3% of private general medical practitioners reported being confronted with alcohol dependence at least once per month, compared with 100% of treatment centre representatives and private psychiatrists, 70.6% of state hospitals and 53.8% of non-prescribers. State hospitals reported the highest frequency for contact with cases of cannabis dependence, compared with the other professional groups, while psychiatrists reported the highest contact with cases involving benzodiazepine, cocaine and ecstasy. Therapists reported a higher level of contact with inhalant dependence, while this group virtually never presented at general practitioners and private psychiatrists. Conclusion. Help-seeking data can be used in conjunction with other data, such as treatment demand data, to inform and adapt policies and practice. Variations in the manifestation of help-seeking behaviour at various groups may be important pointers to conditions that influence help-seeking, and therefore should be investigated further