PLASIM: A computer code for simulating charge exchange plasma propagation

The propagation of the charge exchange plasma for an electrostatic ion thruster is crucial in determining the interaction of that plasma with the associated spacecraft. A model that describes this plasma and its propagation is described, together with a computer code based on this model. The structure and calling sequence of the code, named PLASIM, is described. An explanation of the program's input and output is included, together with samples of both. The code is written in ANSI Standard FORTRAN

Fundamental concepts of structural loading and load relief techniques for the space shuttle

The prediction of flight loads and their potential reduction, using various control system logics for the space shuttle vehicles, is discussed. Some factors not found on previous launch vehicles that increase the complexity are large lifting surfaces, unsymmetrical structure, unsymmetrical aerodynamics, trajectory control system coupling, and large aeroelastic effects. These load-producing factors and load-reducing techniques are analyzed

Review of the genus Ceresium Newman, 1842 (Coleoptera, Cerambycidae) in Fiji

A taxonomic review of the genus Ceresium (Coleoptera: Cerambycidae) found within the Fiji Islands is presented. A total of 17 species is treated. Full morphological descriptions and comparative images of each species are included, along with a dichotomous key for their identification

Structural control interaction

The basic guidance and control concepts that lead to structural control interaction and structural dynamic loads are identified. Space vehicle ascent flight load sources and the load relieving mechanism are discussed, along with the the characteristics and special problems of both present and future space vehicles including launch vehicles, orbiting vehicles, and the Space Shuttle flyback vehicle. The special dynamics and control analyses and test problems apparent at this time are summarized

Stumbling into sexual crime: the passive perpetrator in accounts by male internet sex offenders.

Public reactions to internet child offending remain ambivalent in that, while there is vocal condemnation of contact child sex offending, there is less indignation about internet child abuse. This is potentially due to a lack of recognition of this type of offence as sexual offending per se. This ambiguity is reflected by internet sex offenders themselves in their verbalizations of their offending. This article presents a qualitative analysis of the accounts offered by seven individuals convicted of internet-based sexual offences involving the downloading and viewing of images of children. In particular, this article presents an analysis of the explanations of offenders for the commencement of internet activity and the progression to more illicit online materials. The data were collected through semi-structured interviews and analyzed using discursive methods, paying close attention to language use and function. The analysis documented the practices that internet child abusers employed in order to manage their identities, distance themselves from the label of sex offender, and/or reduce their personal agency and accountability. Implications of this analysis are discussed with reference to the current minimization of the downloading of sexually explicit images of children as a sexual crime per se by the public and offenders alike and the risk assessment and treatment of individuals convicted of these offences

Impact of admission screening for methicillin-resistant Staphylococcus aureus on the length of stay in an emergency department.

Preventing and controlling methicillin-resistant Staphylococcus aureus (MRSA) includes early detection and isolation. In the emergency department (ED), such measures have to be balanced with the requirement to treat patients urgently and transfer quickly to an acute hospital bed. We assessed, in a busy and overcrowded ED, the contribution made to a patient\u27s stay by previous MRSA risk group identification and by selective rescreening of those patients who were previously documented in the research hospital as being MRSA positive. Patients with a previous diagnosis of MRSA colonisation were flagged automatically as \u27risk group\u27 (RG) on their arrival in the ED and were compared with \u27non-risk group\u27 (NRG), i.e. not previously demonstrated in the research hospital to be infected or colonised with MRSA. Over an 18 month period, there were 16 456 admissions via the ED, of which 985 (6%) were RG patients. The expected median times to be admitted following a request for a ward bed for NRG and RG patients were 10.4 and 12.9h, respectively. Female sex, age \u3e65 years, and RG status all independently predicted a statistically significantly longer stay in the ED following a request for a hospital bed. We consider that national and local policies for MRSA need to balance the welfare of patients in the ED with the need to comply with best practice, when there are inadequate ED and inpatient isolation facilities. Patients with MRSA requiring emergency admission must have a bed available for them

Nearly optimal solutions for the Chow Parameters Problem and low-weight approximation of halfspaces

The \emph{Chow parameters} of a Boolean function $f: \{-1,1\}^n \to \{-1,1\}$ are its $n+1$ degree-0 and degree-1 Fourier coefficients. It has been known since 1961 (Chow, Tannenbaum) that the (exact values of the) Chow parameters of any linear threshold function $f$ uniquely specify $f$ within the space of all Boolean functions, but until recently (O'Donnell and Servedio) nothing was known about efficient algorithms for \emph{reconstructing} $f$ (exactly or approximately) from exact or approximate values of its Chow parameters. We refer to this reconstruction problem as the \emph{Chow Parameters Problem.} Our main result is a new algorithm for the Chow Parameters Problem which, given (sufficiently accurate approximations to) the Chow parameters of any linear threshold function $f$, runs in time \tilde{O}(n^2)\cdot (1/\eps)^{O(\log^2(1/\eps))} and with high probability outputs a representation of an LTF $f'$ that is \eps-close to $f$. The only previous algorithm (O'Donnell and Servedio) had running time \poly(n) \cdot 2^{2^{\tilde{O}(1/\eps^2)}}. As a byproduct of our approach, we show that for any linear threshold function $f$ over $\{-1,1\}^n$, there is a linear threshold function $f'$ which is \eps-close to $f$ and has all weights that are integers at most \sqrt{n} \cdot (1/\eps)^{O(\log^2(1/\eps))}. This significantly improves the best previous result of Diakonikolas and Servedio which gave a \poly(n) \cdot 2^{\tilde{O}(1/\eps^{2/3})} weight bound, and is close to the known lower bound of $\max\{\sqrt{n},$ (1/\eps)^{\Omega(\log \log (1/\eps))}\} (Goldberg, Servedio). Our techniques also yield improved algorithms for related problems in learning theory

Het 'bijzondere' van de Schelde: de abiotiek van het Schelde-estuarium

The Scheldt estuary is a vast ecosystem in which powerful natural forces prevail. Tidal action is a key element in the functioning of the estuary. The combination of tide and discharge results in a salinity gradient that is characterized by strong variations in the brackish part. The estuary is a highly turbidsystem. The load of suspended solids is determined by acomplex mix of factors. The dynamic interactions of the physicochemical and morphological parameters lead to a range of various habitats, with highly fluctuating conditions. This, together with the very heavy human impact, both morphological and chemical makes the estuary a very stressed environment in which the survival of plants and animals requires special adaptations

Dystroglycan Depletion Impairs Actin-Dependent Functions of Differentiated Kasumi-1 Cells

Background Dystroglycan has recently been characterised in blood tissue cells, as part of the dystrophin glycoprotein complex involved in the differentiation process of neutrophils. Purpose In the present study we have investigated the role of dystroglycan in the human promyelocytic leukemic cell line Kasumi-1 differentiated to macrophage-like cells. Methods We characterised the pattern expression and subcellular distribution of dystroglycans in non-differentiated and differentiated Kasumi-1 cells. Results Our results demonstrated by WB and flow cytometer assays that during the differentiation process to macrophages, dystroglycans were down-regulated; these results were confirmed with qRT-PCR assays. Additionally, depletion of dystroglycan by RNAi resulted in altered morphology and reduced properties of differentiated Kasumi-1 cells, including morphology, migration and phagocytic activities although secretion of IL-1β and expression of markers of differentiation are not altered. Conclusion Our findings strongly implicate dystroglycan as a key membrane adhesion protein involved in actin-based structures during the differentiation process in Kasumi-1 cells