Multiple impacts of the HIV/AIDS epidemic on the aged in rural Uganda

This paper reports research conducted among theaged residents of a rural, Southwestern Ugandanvillage. It documents their knowledge ofHIV/AIDS, their perceptions of their own riskof infection, and the multiple impacts of thecurrent HIV/AIDS epidemic on their lives. Mostolder individuals have a sound understanding ofthe sexual transmission of HIV, and someconsider themselves to be at risk of infectionthrough having multiple sexual partners. Theyattempt to limit their children's exposure toHIV, but many of these children have left thevillage to live in urban areas of relativelyhigh HIV prevalence. The loss of adult childrendeprives the aged of any support these childrenmight have provided as their parents'capabilities declined with advancing age.Female-headed households were more affected inthis way than were male-headed households. TheAIDS epidemic has increased the number ofburials taking place in the village, and theiraccumulated costs, both in time and money, andcreated new hardships for the aged, who alsohave to cope with grief that accompaniescontinuing deaths among their children andtheir contemporaries' children.

Using Theory to Understand the Multiple Determinants of Low Participation in Worksite Health Promotion Programs

Low participation at the employee or worksite level limits the potential public health impact of worksite-based interventions. Ecological models suggest that multiple levels of influence operate to determine participation patterns in worksite health promotion programs. Most investigations into the determinants of low participation study the intrapersonal, interpersonal, and institutional influences on employee participation. Community- and policy-level influences have not received attention, nor has consideration been given to worksite-level participation issues. The purpose of this article is to discuss one macrosocial theoretical perspective—political economy of health—that may guide practitioners and researchers interested in addressing the community- and policy-level determinants of participation in worksite health promotion programs. The authors argue that using theory to investigate the full spectrum of determinants offers a more complete range of intervention and research options for maximizing employee and worksite levels of participation.

Dipeptidyl peptidase IV is a target for covalent adduct formation with the acyl glucuronide metabolite of the anti-inflammatory drug zomepirac

The nonsteroidal anti-inflammatory drug zomepirac (ZP) is metabolised to a chemically reactive acyl glucuronide conjugate (ZAG) which can form covalent adducts with proteins. In vivo, such adducts could initiate immune or toxic responses. In rats given ZP, the major band detected in liver homogenates by immunoblotting with a polyclonal ZP antiserum was at 110 kDa. This adduct was identified as ZP-modified dipeptidyl peptidase IV (DPP IV) by immunoblotting using the polyclonal ZP antiserum and monoclonal DPP IV antibodies OX-61 and 236.3. In vitro, ZAG, but not ZP itself, covalently modified recombinant human and rat DPP IV. Both monoclonal antibodies recognized DPP IV in livers from ZP- and vehicle-dosed rats. Confirmation that the 110 kDa bands which were immunoreactive with the ZP and DPP IV antibodies represented the same molecule was obtained from a rat liver extract reciprocally immunodepleted of antigens reactive with these two antibodies. Furthermore, immunoprecipitations with OX-61 antibody followed by immunolotting with ZP antiserum, and the reciprocal experiment, showed that both these antibodies recognised the same 110 kDa molecule in extracts of ZP-dosed rat liver. The results verify that DPP IV is one of the protein targets for covalent modification during hepatic transport and biliary excretion of ZAG in rats. (C) 2001 Elsevier Science Inc. All rights reserved.

Multiple bifurcations in atom optics

We report the observation of multiple bifurcations in a nonlinear Hamiltionian system: laser-cooled atoms in a standing wave with single-frequency intensity modulation. We provide clear evidence of the occurrence of bifurcations by analyzing the atomic momentum distributions.

Fluorescence spectrum of a two-level atom driven by a multiple modulated field

We investigate the fluorescence spectrum of a two-level atom driven by a multiple amplitude-modulated field. The driving held is modeled as a polychromatic field composed of a strong central (resonant) component and a large number of symmetrically detuned sideband fields displaced from the central component by integer multiples of a constant detuning. Spectra obtained here differ qualitatively from those observed for a single pair of modulating fields [B. Blind, P.R. Fontana, and P. Thomann, J. Phys. B 13, 2717 (1980)]. In the case of a small number of the modulating fields, a multipeaked spectrum is obtained with the spectral features located at fixed frequencies that are independent of the number of modulating fields and their Rabi frequencies. As the number of the modulating fields increases, the spectrum ultimately evolves to the well-known Mellow triplet with the sidebands shifted from the central component by an effective Rabi frequency whose magnitude depends on the initial relative phases of the components of the driving held. For equal relative phases, the effective Rabi frequency of the driving field can be reduced to zero resulting in the disappearance of fluorescence spectrum, i.e., the atom can stop interacting with the field. When the central component and the modulating fields are 180 degrees out of phase, the spectrum retains its triplet structure with the sidebands located at frequencies equal to the sum of the Rabi frequencies of the component of the driving field. Moreover, we shaw that the frequency of spontaneous emission can be controlled and switched from one frequency to another when the Rabi frequency or initial phase of the modulating fields are varied.

Inhibitors of human immunodeficiency virus type 1 reverse transcriptase target distinct phases of early reverse transcription

Early HIV-1 reverse transcription can be separated into initiation and elongation phases. Here we show, using PCR analysis of negative-strand strong-stop DNA [(-)ssDNA] synthesis in intact virus, that different reverse transcriptase (RT) inhibitors affect distinct phases of early natural endogenous reverse transcription (NERT), The effects of nevirapine on NERT were consistent with a mechanism of action including both specific and nonspecific binding events. The nonspecific component of this inhibition targeted the elongation reaction, whereas the specific effect seemed principally to be directed at very early events (initiation or the initiation-elongation switch), In contrast, foscarnet and the nucleoside analog ddATP inhibited both early and late (-)ssDNA synthesis in a similar manner. We also examined compounds that targeted other viral proteins and found that Ro24-7429 (a Tat antagonist) and rosmarinic acid (an integrase inhibitor) also directly inhibited RT, Our results indicate that NERT can be used to identify and evaluate compounds that directly target the reverse transcription complex.

Articulatory dysfunction in multiple sclerosis: An electropalatographic study

Dysfunction of the articulatory subsystem (i.c.. the lips, tongue, and jaw) has bccn identified as a major contributor to the reduction in speech intelligibility experienced by a high proportion of people with multiple sclerosis (MS). In particular. consonant imprecision has been reported to be the articulatory deficit that contributes most to variations in overall intelligibility of MS speakers. Electropalatography(EPG) IS an instrurncntal technique that visually documents the location and timing of tongue-topalatc contacts during speech. Although such a technique would be valuablc in objectively assessing the articulatory disturbances exhibited by individuals with dysarthria ia motor speech disorder) associated with MS, to-date no such study ha< been reported. The aim of the present study was to use EPG to assess tongue-to-palate contact patterns and articulatory timing in patients with dysarthria associated with MS. A dysarthric participant with a diagnosis of definite MS was fitted with an acrylic EPG palate (Reading EPG.?) and asked to read aloud a list of single syllable words which contained lingual consonants in the word-initial position and in consonant clusters. Each mord was repeated five times. The EPG palate was specifically moulded to tit the participant's hard palate and contained 62 electrodes that detected the tongue contacts. A non-neurologically impaired participant matched for age and sex servcd as a control. The results of the study revealed that the tongue-to-palate contacts produced by the participant with MS varied from those produced by the control in a number of ways in regard to spatial configurations and timing characteristics exhibited. The rcsults arc discussed in relation to the neuropathophysiological effects of MS on speech production. The potcntial use of EPG in programs for treating speech disorders associated with MS will be highlightcd.

A multiple-outgroup approach to resolving division-level phylogenetic relationships using 16S rDNA data

The 16S rRNA gene (16S rDNA) is currently the most widely used gene for estimating the evolutionary history of prokaryotes, To date, there are more than 30 000 16S rDNA sequences available from the core databases, GenBank, EMBL and DDBJ, This great number may cause a dilemma when composing datasets for phylogenetic analysis, since the choice and number of reference organisms are known to affect the resulting tree topology. A group of sequences appearing monophyletic in one dataset may not be so in another. This can be especially problematic when establishing the relationships of distantly related sequences at the division (phylum) level. In this study, a multiple-outgroup approach to resolving division-level phylogenetic relationships is suggested using 16S rDNA data. The approach is illustrated by two case studies concerning the monophyly of two recently proposed bacterial divisions, OP9 and OP10.

A novel target-field method for finite-length magnetic resonance shim coils: I. Zonal shims

This paper presents a new approach for the design of genuinely finite-length shim and gradient coils, intended for use in magnetic resonance imaging equipment. A cylindrical target region is located asymmetrically, at an arbitrary position within a coil of finite length. A desired target field is specified on the surface of that region, and a method is given that enables winding patterns on the surface of the coil to be designed, to produce the desired field at the inner target region. The method uses a minimization technique combined with regularization, to find the current density on the surface of the coil. The method is illustrated for linear, quadratic and cubic magnetic target fields located asymmetrically within a finite-length coil.

Using MF-PCR to diagnose multiple defects from single cells: implications for PGD

Single cell genetic analysis is generally performed using PCR and FISH. Until recently, FISH has been the method of choice. FISH however is expensive, has significant misdiagnosis rates, can result in interpretation difficulties and is labour intensive making it unsuitable for high throughput processing. Recently fluorescent PCR reliability has increased to levels at or surpassing FISH whilst maintaining low cost. However, PCR accuracy has been a concern due to allelic dropout. Multiplex PCR can now increase accuracy by using multiple markers for each chromosome to firstly provide diagnosis if markers fail and,or secondly confirm diagnosis. We compare a variety of diagnostic methods and demonstrate for the first time a multiplex PCR system providing simultaneous diagnosis and confirmation of the major aneuploidy chromosomes (21, 18, 13) and sex as well as DNA fingerprint in single cells. We also discuss the implications of using PCR for aneuploidy screening in preimplantation genetic diagnosis. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.

Monocular and binocular distance cues: insights from visual form agnosia I (of III)

The human nervous system constructs a Euclidean representation of near (personal) space by combining multiple sources of information (cues). We investigated the cues used for the representation of personal space in a patient with visual form agnosia (DF). Our results indicated that DF relies predominantly on binocular vergence information when determining the distance of a target despite the presence of other (retinal) cues. Notably, DF was able to construct an Euclidean representation of personal space from vergence alone. This finding supports previous assertions that vergence provides the nervous system with veridical information for the construction of personal space. The results from the current study, together with those of others, suggest that: (i) the ventral stream is responsible for extracting depth and distance information from monocular retinal cues (i.e. from shading, texture, perspective) and (ii) the dorsal stream has access to binocular information (from horizontal image disparities and vergence). These results also indicate that DF was not able to use size information to gauge target distance, suggesting that intact temporal cortex is necessary for learned size to influence distance processing. Our findings further suggest that in neurologically intact humans, object information extracted in the ventral pathway is combined with the products of dorsal stream processing for guiding prehension. Finally, we studied the size-distance paradox in visual form agnosia in order to explore the cognitive use of size information. The results of this experiment were consistent with a previous suggestion that the paradox is a cognitive phenomenon.

ReoPro rules: results from the 'DoTirofiban and ReoPro give similar efficacy trial' (TARGET) - A Key Paper Evaluation (Topol, Ej et al)

In the treatment of atherosclerotic disease, stenting in the presence of a glycoprotein (GP) IIb/IIIa antagonist is becoming an increasingly common procedure. The ‘Do Tirofiban and ReoPro Give Similar Efficacy Trial’ (TARGET) was designed to determine whether the cheaper tirofiban was as effective and safe as abciximab in the prevention of ischaemic events with stenting. Unexpectedly, abciximab was shown to be superior to tirofiban. Tirofiban is a selective GP IIb/IIIa antagonist whereas abciximab has additional anti-inflammatory actions, which may contribute to its superiority.

Crystal structure of yeast acetohydroxyacid synthase: A target for herbicidal inhibitors

Acetohydroxyacid synthase (AHAS; EC 4.1.3.18) catalyzes the first step in branched-chain amino acid biosynthesis. The enzyme requires thiamin diphosphate and FAD for activity, but the latter is unexpected, because the reaction involves no oxidation or reduction. Due to its presence in plants, AHAS is a target for sulfonylurea and imidazolinone herbicides. Here, the crystal structure to 2.6 A resolution of the catalytic subunit of yeast AHAS is reported. The active site is located at the dimer interface and is near the proposed herbicide-binding site. The conformation of FAD and its position in the active site are defined. The structure of AHAS provides a starting point for the rational design of new herbicides. (C) 2002 Elsevier Science Ltd.

Air target detection via bistatic radar based on LEOS communication signals

The paper discusses the bistatic radar parameters for the case when the transmitter is a satellite emitting communication signals. The model utilises signals from an Iridium-like low earth orbiting satellite system. The maximum detection range, when thermal noise-limited, is discussed at the theoretical level and these results are compared with experimentation. Satellite-radar signal levels and the power of ground reflections are evaluated.