A L\'evy input fluid queue with input and workload regulation

We consider a queuing model with the workload evolving between consecutive i.i.d.\ exponential timers $\{e_q^{(i)}\}_{i=1,2,...}$ according to a spectrally positive L\'evy process $Y_i(t)$ that is reflected at zero, and where the environment $i$ equals 0 or 1. When the exponential clock $e_q^{(i)}$ ends, the workload, as well as the L\'evy input process, are modified; this modification may depend on the current value of the workload, the maximum and the minimum workload observed during the previous cycle, and the environment $i$ of the L\'evy input process itself during the previous cycle. We analyse the steady-state workload distribution for this model. The main theme of the analysis is the systematic application of non-trivial functionals, derived within the framework of fluctuation theory of L\'evy processes, to workload and queuing models

Tuberculosis in a South African prison – a transmission modelling analysis

Background. Prisons are recognised internationally as institutions with very high tuberculosis (TB) burdens where transmission is predominantly determined by contact between infectious and susceptible prisoners. A recent South African court case described the conditions under which prisoners awaiting trial were kept. With the use of these data, a   mathematical model was developed to explore the interactions between incarceration conditions and TB control measures.Methods. Cell dimensions, cell occupancy, lock-up time, TB incidence and treatment delays were derived from court evidence and judicial reports. Using the Wells-Riley equation and probability analyses of contact between prisoners, we estimated the current TB transmission probability within prison cells, and estimated transmission probabilities of improved levels of case finding in combination with implementation of national and  international minimum standards for incarceration.Results. Levels of overcrowding (230%) in communal cells and poor TB case finding result in annual TB transmission risks of 90% per annum. Implementing current national or international cell occupancy  recommendations would reduce TB transmission probabilities by 30% and 50%, respectively. Improved passive case finding, modest ventilation increase or decreased lock-up time would minimally impact on transmission if introduced individually. However, active case finding together with implementation of minimum national and international standards of incarceration could reduce transmission by 50% and 94%, respectively.Conclusions. Current  conditions of detention for awaiting trial prisoners are highly conducive for spread of drug-sensitive and drug-resistant TB. Combinations of simple well-established scientific control measures should be implemented urgently.S Afr Med J 2011;101:809-813

Optical spectroscopy of complex open 4dd-shell ions Sn7+^{7+}-Sn10+^{10+}

We analyze the complex level structure of ions with many-valence-electron open [Kr] 4$d^\textrm{m}$ sub-shells ($\textrm{m}$=7-4) with ab initio calculations based on configuration-interaction many-body perturbation theory (CI+MBPT). Charge-state-resolved optical and extreme ultraviolet (EUV) spectra of Sn$^{7+}$-Sn$^{10+}$ ions were obtained using an electron beam ion trap. Semi-empirical spectral fits carried out with the orthogonal parameters technique and Cowan code calculations lead to 90 identifications of magnetic-dipole transitions and the determination of 79 energy ground-configuration levels, questioning some earlier EUV-line assignments. Our results, the most complete data set available to date for these ground configurations, confirm the ab initio predictive power of CI+MBPT calculations for the these complex electronic systems.Comment: 18 pages, 5 figure

Tuberculosis in a South African prison - a transmission modelling analysis

Background. Prisons are recognised internationally as institutions with very high tuberculosis (TB) burdens where transmission is predominantly determined by contact between infectious and susceptible prisoners. A. recent South African court case described the conditions under which prisoners awaiting trial were kept. With the use of these data, a mathematical model was developed to explore the interactions between incarceration conditions and TB control measures. Methods. Cell dimensions, cell occupancy, lock-up time, TB incidence and treatment delays were derived from court evidence and judicial reports. Using the Wells-Riley equation and probability analyses of contact between prisoners, we estimated the current TB transmission probability within prison cells, and estimated transmission probabilities of improved levels of case finding in combination with implementation of national and international minimum standards for incarceration. Results. Levels of overcrowding (230%) in communal cells and Poor TB case finding result in annual TB transmission risks of 90% per annum. Implementing current national or international cell occupancy recommendations would reduce TB transmission probabilities by 30% and 50%, respectively. Improved passive case finding, modest ventilation increase or decreased lock-up time would minimally impact on transmission if introduced individually. However, active case finding together with implementation of minimum national and international standards of incarceration could reduce transmission by 50% and 94%, respectively. Conclusions. Current conditions of detention for awaiting-trial prisoners are highly conducive for spread of drug-sensitive and drug-resistant TB. Combinations of simple well-established scientific control measures should be implemented urgently

Orthogonal Bases of Invariants in Tensor Models

Representation theory provides a suitable framework to count and classify invariants in tensor models. We show that there are two natural ways of counting invariants, one for arbitrary rank of the gauge group and a second, which is only valid for large N. We construct bases of invariant operators based on the counting, and compute correlators of their elements. The basis associated with finite N diagonalizes the two-point function of the theory and it is analogous to the restricted Schur basis used in matrix models. We comment on future lines of investigation.Comment: Two overlapping but independent results are merged to a joint work. 16 pages, 1 tabl

BORON PREPARATIONS IN PSYCHIATRY AND NEUROLOGY: THEIR RISE, FALL AND RENEWED INTEREST

The use of boron preparations (borax and boric acid) in medicine began long before their isolation in pure form. The mineral water of  boron-containing sources has been historically used to treat skin  diseases, to wash eyes, to disinfect wounds, etc. Also, what is of  interest in the context of this article, boron-containing waters were  used as calming, anti- anxiety, anticonvulsant and sleep-promoting  remedy. In 1777, boric acid was first isolated from the mineral water of a healing spring source in Florence. Historically, first name  of this compound was sal sedativum (“soothing salt”). However, the  discovery of boron toxicity led to the cessation of its internal use. In  recent decades, it has been found that boron is a microelement  necessary for many metabolic processes in the body. It affects  memory, cognitive functions, anxiety level, sleep, mood, regulates  calcium and magnesium exchange, metabolism of vitamin D and sex  steroids. It has been shown that some cases of treatment  resistance to standard therapy, for example in epilepsy, anxiety and depression, are related to boron deficiency. In this regard,  interest in the use of boron preparations in psychiatry and neurology, but in much smaller doses and on new scientific grounds, flared up again

Lithium Preparations in Psychiatry, Addiction Medicine and Neurology. Part II. Biochemical Mechanisms of Its Action

Lithium is the first and the lightest in the series of alkali metals, to which, in addition to lithium, two very biologically important elements – sodium and potassium, as well as trace elements rubidium and cesium, belong. Despite its formal affiliation to the group of alkali metals, lithium, like many other chemical elements of the «atypical» second period of the periodic table (for example, boron), is more similar in its chemical properties not to its counterparts in the group, but to its «diagonal brother» – magnesium. As we will show in this article, the diagonal chemical similarity between lithium and magnesium is of great importance for understanding the mechanisms of its intracellular biochemical action. At the same time, the intragroup chemical similarity of lithium with sodium and potassium is more important for understanding the mechanisms of its absorption, its distribution in the body and its excretion. Despite the 70 years that have passed since John Cade’s discovery of the antimanic effect of lithium, the mechanisms of its therapeutic action are still not completely understood. In the end, it turns out that the mechanism of the therapeutic action of lithium is extremely complex, multicomponent, unique and not imitable. Certain aspects of the mechanism of its action may be compatible with the mechanisms of action of other mood stabilizers, or with the mechanisms of action of so-called «lithium-mimetics», such as ebselen. However, no other drug to date failed to fully reproduce the biochemical effect of lithium on the body

Electroconvulsive Therapy as a Corrector for Certain Side Effects of Antipsychotic Therapy

The discovery of the first typical antipsychotics in the 1950s had revolutionized the treatment of many severe mental illnesses. This discovery opened the door for radical humanization and deinstitutionalization of the whole psychiatry. It also served as an impetus for the emergence of a new science, called psychopharmacology. This signaled the beginning of an era of widespread use of psychopharmacotherapy in psychiatry. However, the use of typical antipsychotics has been associated with many side effects, including severe ones, such as severe extrapyramidal syndrome, neuroleptic-induced deficit syndrome, cognitive impairment, and neuroleptic malignant syndrome. This necessitated the development of methods for correction or treatment of such side effects.Over the past decades, a number of new antipsychotics have been synthesised and approved for clinical use. Those new drugs are considered to belong to the group of so-called «atypical antipsychotics». This group, as a whole, has an improved tolerance and safety profile compared to older, conventional antipsychotics. In particular, these new drugs less often cause exactly the aforementioned side effects. Nevertheless, the problem of antipsychotic side effects and their correction is still far from being resolved. Some patients experiencing certain side effects from antipsychotic therapy do not get adequate relief from the standard pharmacological correction of those side effects.This fact stimulated our interest in the study of the possibilities of using electroconvulsive therapy as an alternative or adjuvant method for the correction of some side effects that can arise during antipsychotic therapy. In this article, we thoroughly discuss the existing evidence base regarding the effectiveness and safety of the use of electroconvulsive therapy as a corrector for certain side effects that can occur during antipsychotic therapy

Critical review of leaflets about conservative management used in UK renal services

Background: Written information supplements nurse‐led education about treatment options. It is unclear if this information enhances patients’ reasoning about conservative management (CM) and renal replacement therapy decisions. Aim: This study describes a critical review of resources U.K. renal staff use when providing CM options to people with Established Kidney Disease (EKD) during usual pre‐dialysis education. Design: A survey using mixed methods identified and critically analysed leaflets about CM. Participants & measurements: All 72 renal units in the United Kingdom received an 11‐item questionnaire to elicit how CM education is delivered, satisfaction and/or needs with patient resources and staff training. Copies of leaflets were requested. A coding frame was utilised to produce a quality score for each leaflet. Results: Fifty‐four (75%) units participated. Patients discuss CM with a nephrologist (98%) or nurse (100%). Eighteen leaflets were reviewed, mean scores were 8.44 out of 12 (range 5–12, SD = 2.49) for information presentation; 3.50 out of 6 (range 0–6, SD = 1.58) for inclusion of information known to support shared decision‐making and 2.28 out of 6 (range 1–4, SD = 0.96) for presenting non‐biased information. Conclusions: Nurses preferred communicating via face‐to‐face contact with patients and/or families because of the emotional consequences and complexity of planning treatment for the next stage of a person's worsening kidney disease. Conversations were supplemented with written information; 66% of which were produced locally. Staff perceived a need for using leaflets, and spend time and resources developing them to support their services. However, no leaflets included the components needed to help people reason about conservative care and renal replacement therapy options during EKD education consultations