Perception of PrEP-related stigma in PrEP users: Results from the ANRS-PREVENIR cohort.

INTRODUCTION: Since the advent of HIV pre-exposure prophylaxis (PrEP), stigma has been shown to be a major barrier to its uptake and adherence. It is therefore essential to define the proportion of users who consider that PrEP can negatively impact their image and the factors associated with this perception. METHOD: We performed a multivariable logistic regression on data from the 2567 participants in the ANRS-PREVENIR study who answered the outcome question. RESULTS: Almost one-third of the sample (comprising mostly cisgender men who have sex with men [94.3%]) considered that taking PrEP could give others a negative image of them. Younger participants (adjusted odds ratio [aOR] 0.98; 95% confidence interval [CI] 0.97-0.99) and more psychologically vulnerable participants (i.e., lower self-esteem score [aOR 0.98; 95% CI 0.96-0.99] and higher depression score [aOR 1.02; 95% CI 1.00-1.03]) were also more likely to have this perception. In contrast, participants encouraged to take PrEP by their main partner (aOR 0.67; 95% CI 0.51-0.88) and friends (aOR 0.79; 95% CI 0.66-0.95), and those who protected themselves more because they had knowledge of their most recent sexual partner's HIV status (aOR 0.83; 95% CI 0.69-0.99) and systematic use of PrEP and/or condoms during intercourse in the previous 3 months (aOR 0.80; 95% CI 0.67-0.96) were less likely to have this perception. DISCUSSION: Given the strong interrelation between stigmatization (real or perceived), risky behaviours and adherence, our results emphasize the need for HIV prevention campaigns to promote a positive image of PrEP users. They also show that stigmatization and its effects need to be fully considered to improve HIV prevention offers to current and potential PrEP users who are most likely to be psychologically vulnerable.

Perioperative stroke during carotid endarterectomy: benefits of multimodal neuromonitoring - a case report.

BACKGROUND: Carotid endarterectomy is routinely performed after ischemic stroke due to carotid stenosis. Perioperative, cerebral blood flow and oxygenation can be monitored in different ways, but there is no clear evidence of a gold standard and a uniform guideline is lacking. Electroencephalography and near-infrared spectroscopy are among the most frequently used methods of neuromonitoring. Clinicians should be aware of their pitfalls and the added value of transcranial doppler. CASE PRESENTATION: We present the case of an 85-year old male with perioperative haemodynamic stroke during carotid endarterectomy. Ischemic stroke was caused by suddenly increased carotid stenosis resulting in major neurologic deficit. This was registered only by transcranial doppler, while surface electroencephalography and near-infrared spectroscopy failed to detect any significant change in cerebral perfusion, despite a large perfusion defect on computed tomography. Circulation was restored with endovascular treatment and neurologic deficit quickly resolved. CONCLUSION: We strongly advocate the practice of multimodal neuromonitoring including transcranial doppler whenever possible to minimize the risk of persistent neurologic deficit due to perioperative stroke during carotid endarterectomy.

Rise of nations: Why do empires expand and fall?

We consider centralized networks composed of multiple satellites arranged around a few dominating super-egoistic centers. These so-called empires are organized using a divide and rule framework enforcing strong center-satellite interactions while keeping the pairwise interactions between the satellites sufficiently weak. We present a stochastic stability analysis, in which we consider these dynamical systems as stable if the centers have sufficient resources while the satellites have no value. Our model is based on a Hopfield type network that proved its significance in the field of artificial intelligence. Using this model, it is shown that the divide and rule framework provides important advantages: it allows for completely controlling the dynamics in a straight-forward way by adjusting center-satellite interactions. Moreover, it is shown that such empires should only have a single ruling center to provide sufficient stability. To survive, empires should have switching mechanisms implementing adequate behavior models by choosing appropriate local attractors in order to correctly respond to internal and external challenges. By an analogy with Bose-Einstein condensation, we show that if the noise correlations are negative for each pair of nodes, then the most stable structure with respect to noise is a globally connected network. For social systems, we show that controllability by their centers is only possible if the centers evolve slowly. Except for short periods when the state approaches a certain stable state, the development of such structures is very slow and negatively correlated with the size of the system's structure. Hence, increasing size eventually ends up in the "control trap."

Single versus multiple metabolite quantification of in vitro starch digestion: A comparison for the case of pulse cotyledon cells.

Different quantification methods for in vitro amylolysis were compared for individual chickpea and lentil cotyledon cells (ICC) as a relevant case study. For the first time, much-applied spectrophotometric methods relying on the quantification of certain functional groups (i.e., DNS, GOPOD) were compared to chromatographic quantification of starch metabolites (HPLC-ELSD). The estimated rate constant and linked initial rates of amylolysis were highly correlated for DNS, GOPOD, and HPLC-ELSD. However, absolute amylolysis levels depended on the applied method and sample-specific metabolite formation patterns. Multiresponse modelling was employed to further investigate HPLC-ELSD metabolite formation patterns. This delivered insight into the relative importance of different amylolysis reactions during in vitro digestion of pulse ICC, proving that maltotriose and maltose formation determined the overall amylolysis rate in this case. Multiresponse reaction rate constants of maltotriose and maltose formation were highly correlated to single response amylolysis rate constants (and initial rates) obtained for all three quantification methods.

Studying semi-dynamic digestion kinetics of food: Establishing a computer-controlled multireactor approach.

In this work, a multireactor system to study digestion (MuReDi) kinetics is introduced. For this, a custom-made automated system with four independent syringe pumps (BioXplorer 100, H.E.L Group) was acquired. This system consists of multiple, small-scale reactors allowing to study digestion as a function of time and thus to determine digestion kinetics. The different digestion conditions used in the oral, gastric, and small intestinal phase were based on the digestion protocols published by the INFOGEST consortium. We showed that the minimum working volume of a reactor is 30 mL. Besides, repeatability of the digestion kinetics was shown for two food systems: a liquid Ensure® Plus Vanilla drink, and a solid, cooked lentil sample. When comparing static digestion kinetics with semi-dynamic ones, a significantly different digestion pattern was observed. In the static case, a relatively fast hydrolysis rate was observed until a clear plateau was reached. Oppositely, for the semi-dynamic case, a delayed start of the hydrolysis process was noticed. In the gastric phase, this was explained by the decreasing pH and the large pH dependency of pepsin activity. In the small intestine, the lag phase was relatively shorter, yet clearly present. Here we related it to the gradual enzyme (and bile salt) secretion that had to diffuse towards the substrate before hydrolysis could start. Generally, this work showed that the MuReDi system could be used to perform a semi-dynamic digestion approach which largely impacted the overall digestion kinetics. This is important to consider in future in vitro food digestion simulation work to come closer to physiologically relevant digestion kinetics.

Features of structure, magnetic state and electrodynamic performance of SrFe12-xInxO19.

Indium-substituted strontium hexaferrites were prepared by the conventional solid-phase reaction method. Neutron diffraction patterns were obtained at room temperature and analyzed using the Rietveld methods. A linear dependence of the unit cell parameters is found. In3+ cations are located mainly in octahedral positions of 4fVI and 12 k. The average crystallite size varies within 0.84-0.65 µm. With increasing substitution, the TC Curie temperature decreases monotonically down to ~ 520 K. ZFC and FC measurements showed a frustrated state. Upon substitution, the average and maximum sizes of ferrimagnetic clusters change in the opposite direction. The Mr remanent magnetization decreases down to ~ 20.2 emu/g at room temperature. The Ms spontaneous magnetization and the keff effective magnetocrystalline anisotropy constant are determined. With increasing substitution, the maximum of the ε/ real part of permittivity decreases in magnitude from ~ 3.3 to ~ 1.9 and shifts towards low frequencies from ~ 45.5 GHz to ~ 37.4 GHz. The maximum of the tg(α) dielectric loss tangent decreases from ~ 1.0 to ~ 0.7 and shifts towards low frequencies from ~ 40.6 GHz to ~ 37.3 GHz. The low-frequency maximum of the µ/ real part of permeability decreases from ~ 1.8 to ~ 0.9 and slightly shifts towards high frequencies up to ~ 34.7 GHz. The maximum of the tg(δ) magnetic loss tangent decreases from ~ 0.7 to ~ 0.5 and shifts slightly towards low frequencies from ~ 40.5 GHz to ~ 37.7 GHz. The discussion of microwave properties is based on the saturation magnetization, natural ferromagnetic resonance and dielectric polarization types.

Method of surface energy investigation by lateral AFM: application to control growth mechanism of nanostructured NiFe films.

A new method for the specific surface energy investigation based on a combination of the force spectroscopy and the method of nanofriction study using atomic force microscopy was proposed. It was shown that air humidity does not affect the results of investigation by the proposed method as opposed to the previously used methods. Therefore, the method has high accuracy and repeatability in air without use of climate chambers and liquid cells. The proposed method has a high local resolution and is suitable for investigation of the specific surface energy of individual nanograins or fixed nanoparticles. The achievements described in the paper demonstrate one of the method capabilities, which is to control the growth mechanism of thin magnetic films. The conditions for the transition of the growth mechanism of thin Ni80Fe20 films from island to layer-by-layer obtained via electrolyte deposition have been determined using the proposed method and the purpose made probes with Ni coating.

[Community-Based Testing and Factors Associated with HIV among Men Who Have Sex with Men (MSM) in Haiti between 2015 and 2018]. / Dépistage communautaire et facteurs associés au VIH d'hommes ayant des relations sexuelles avec des hommes (HSH) en Haïti entre 2015 et 2018.

Men who have sex with men (MSM) are an HIV key population in Haiti. However, little data exists on that population and on factors associated with this infection. Our study carried out the factors associated with HIV-positive screening among MSM in a community-based rapid testing program in Haiti between 2015 and 2018. Among the 1416 MSM screened, a third reported that it was their very first HIV test and 7.0% had an HIV-positive test. With a median age of 25 years old [21-29], over half of them were living in urban areas (60.7%) and were in financial precarious conditions (68.6%). Multivariate analysis showed that two factors were significantly associated with an HIVpositive result: having had an STI in the last 12 months, strengthened by psychoactive drug use; transactional sex practice in the last 12 months, strengthened by the age between 18 and 20 years old. These results should be taken into account when developing and implementing targeted and comprehensive HIV prevention programs and services for young MSM in Haiti.

Les hommes ayant des relations sexuelles avec des hommes (HSH) constituent une population clé du virus de l'immunodéficience humaine (VIH) en Haïti. Cependant, peu de données existent sur cette population et les facteurs associés à cette infection. Notre étude s'intéresse aux facteurs liés à un test rapide positif au VIH chez les HSH dans le cadre d'un dispositif de dépistage communautaire en Haïti entre 2015 et 2018. Parmi les 1 416 HSH dépistés, un tiers déclaraient leur premier test VIH et 7,0 % avaient un résultat positif. Avec un âge médian de 25 ans [21­29], plus de la moitié d'entre eux vivaient en milieu urbain (60,7 %) et étaient en situation de précarité financière (68,6 %). Une analyse multivariée a montré que deux facteurs étaient significativement associés à un résultat positif au VIH : avoir eu une infection sexuellement transmissible dans les 12 derniers mois, facteur accentué lorsqu'il est combiné à une consommation de produits psychoactifs ; la pratique du sexe transactionnel dans les 12 derniers mois, facteur accentué par l'appartenance à la classe d'âge des 18­20 ans. Ces résultats doivent se traduire dans la mise en place de futurs programmes et services de prévention du VIH vers les jeunes HSH en Haïti.

Observations of a comet on collision course with the sun.

A brilliant new comet (1979 XI: Howard-Koomen-Michels) was discovered in data from the Naval Research Laboratory's orbiting SOLWIND coronagraph. An extensive sequence of pictures, telemetered from the P78-1 satellite, shows the coma, accompanied by a bright and well-developed tail, passing through the coronagraph's field of view at afew million kilometers from the sun. Preliminary orbital calculations based on the observed motion of the comet's head and morphology of the tail indicate that this previously unreported object is a sungrazing comet and may be one of the group of Kreutz sungrazers. It appears from the data that the perihelion distance was less than 1 solar radius, so that the cometary nucleus encountered dense regions of the sun's atmosphere, was completely vaporized, and did not reappear after the time of closest approach to the sun. After this time, however, cometary debris, scattered into the ambient solar wind, caused a brightening of the corona over one solar hemisphere and to heliocentric distances of 5 to 10 solar radii.

Isolation of DICE1: a gene frequently affected by LOH and downregulated in lung carcinomas.

In the development and progression of sporadic tumors multiple tumor suppressor genes are inactivated that may be distinct from predisposing cancer genes. Previously, a tumor suppressor locus on human chromosome 13q14 that is distinct from the retinoblastoma predisposing gene 1 (RB1) has been identified in lung, head and neck, breast, ovarian and prostate tumors. By an approach that combines genomic difference cloning and positional cloning we isolated the cDNA of a novel gene (DICE1) located at 13q14.12-14.2. The DICE1 gene is highly conserved in evolution and its mRNA is expressed in a wide variety of fetal and adult tissues. The DICE1 cDNA encodes a predicted protein of 887 amino acids corresponding to an 100 kD protein that shows 92.9% identity to the carboxy-terminal half of the mouse EGF repeat transmembrane protein DBI-1. The DBI-1 protein interferes with the mitogenic response to insulin-like growth factor 1 (IGF-I) and is presumably involved in anchorage-dependent growth. When compared to normal lung tissue expression of the DICE1 mRNA was reduced or undetectable in the majority of non-small cell lung carcinomas analysed. The location of the DICE1 gene in the region of allelic loss, its high evolutionary conservation and the downregulation of expression in carcinoma cells suggests that DICE1 is a candidate tumor suppressor gene in non-small cell lung carcinomas and possibly in other sporadic carcinomas.

Faithful in vitro transcription by fission yeast RNA polymerase III reveals unique alpha-amanitin sensitivity.

Transcription with fission yeast (Schizosaccharomyces pombe) RNA polymerase III (pol III) was studied in two different in vitro systems. Reactions performed with isolated nuclei gave rise to 5S and pre-tRNA molecules. Because the alpha-amanitin sensitivity of that reaction clearly differed from what has been observed with pol III enzymes of other eukaryotes, a cell-free S. pombe transcription extract was developed and analyzed with the homologous 7S L RNA (srp RNA; signal recognition particle RNA) gene. Synthesis of 7S L RNA was found to be sensitive to high concentrations of alpha-amanitin, with 50% reduction seen at 400 microg/ml of the toxin. However, even with very high alpha-amanitin concentrations, exceeding 1 mg/ml, no full inhibition of the S. pombe pol III enzyme could be obtained. Together, these results demonstrate that in contrast to the yeast Saccharomyces cerevisiae, pol III from S. pombe is sensitive to high concentrations of alpha-amanitin, yet with a clearly different dose response than that observed with the corresponding RNA polymerase of higher eukaryotes. Furthermore, while the S. pombe 7S L RNA gene was efficiently transcribed in HeLa cell extracts, the human 7S L RNA gene was not actively transcribed in the S. pombe system. This finding of divergent promoter structures of both genes was verified by the analysis of 5' deletion mutants of the S. pombe 7S L RNA gene.

Frequency and distribution of 22,836 adult cancer cases referred to King Faisal Specialist Hospital and Research Centre.

Since late 1975, the King Faisal Specialist Hospital and Research Centre (KFSH&RC), a tertiary-care hospital in Saudi Arabia, has continuously collected data on its experience in oncology. With 22,836 cancer cases as a base, covering the years between 1976 and 1993, it is intended to present the hospital data obtained in this referral center as a prelude to the release of statistics from the Saudi Arabia National Cancer Registry (NCR) established in 1994. It will be interesting to see whether the data collected in the largest cancer referral center in the Kingdom will be comparable with national data when this becomes available. Our intent is to identify trends of referral and any possible bias in the data when compared to the NCR statistics of 1994.

Detectors for the extreme ultraviolet. I: photomultipliers used in the dc output current mode.

An investigation has been made of voltage-sensitivity characteristics, absolute spectral response, dark current and output current limitations of seven photomultipliers suitable for detection of extreme uv radiation. These photomultipliers are windowless types, utilizing cathode surfaces blind to visible and near uv radiation; they include a microminiature continuous channel multiplier. For measurements of absolute spectral sensitivity, they were compared to a conventional 1P21, coated with sodium salicylate which, in turn, had been calibrated at 1216 A with a nitric oxide ionization chamber. The spectral response measurements cover the spectral region from 1500 A to 584 A. The photomultipliers were used in a dc output currrent mode and were excited with radiation from both pulsed and dc gas discharge sources. A discussion of the suitability of the detectors for use with each type of source is given.

Distribution of pulmonary ventilation and perfusion during short periods of weightlessness.

Information on the distributions of pulmonary ventilation and perfusion was obtained from four subjects on board a Learjet during 112 weightless periods lasting up to 27 s each. Zero gravity (G) was obtained during all or part of each test by varying the aircraft flight profile. Single-breath N2 washouts were performed with the test inspiration containing an initial bolus of argon at residual volume (RV). When the test inspiration was at 0 G, and the washout at 0 G or greater, the terminal rises and the cardiogenic oscillations in both N2 and argon were small and often absent. If instead the test inspiration was at 1 G with the washout at 0 G, the terminal rises were again small or absent but the cardiogenic oscillations remained. The terminal rise and the cardiogenic oscillations for N2, but not argon, were also nearly eliminated by performing just the preliminary exhalation to RV at 0 G with the test inspiration and washout following at 1 G. Aleveolar plateaus for N2 sloped upward at 0 G apparently due to nontopographical inequalities of ventilation. In further tests during air breathing, recordings were made of expired partial pressure of oxygen PO2) and carbon dioxide (POO2) following a brief hyperventilation and a 15-s breath hold. These recordings revealed marked cardiogenic oscillations in PO2 and PCO2 at 1 G that were enhanced at 2 G but almost eliminated at 0 G. The results suggest that virtually all the topographical inequality of ventilation, blood flow, and lung volume seen under 1-G conditions are abolished during short periods of 0 G.

The relational clinical database: a possible solution to the star wars in registry systems.

In summary, having data from other service areas available in a relational clinical database could resolve many of the problems existing in today's registry systems. Uniting sophisticated information systems into a centralized database system could definitely be a corporate asset in managing the bottom line.

Radiographic comparison of human lung shape during normal gravity and weightlessness.

Human lung shape was measured during zero gravity (0 G) to decide whether the normal vertical regional differences in ventilation are due directly to distortion of the elastic lung by its own weight, or instead, due indirectly to the effect of gravity on the shape of the rib cage and diaphragm. This was important because we previously established that weightlessness virtually abolishes the normal topographical inequality of ventilation (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 45: 987-998, 1978). Chest radiographs were made after 10 s of a weightless flight trajectory aboard a NASA-Ames Research Center Learjet in both posterior-anterior and left lateral projections on five seated volunteers at residual volume, functional residual capacity, and total lung capacity. Lung shape was assessed by measuring lung heights and widths in upper, middle, and lower lung regions. We found no significant differences between any of the normal gravity (1 G) and o G measurements, although there was a slight tendency for the lung to become shorter and wider at o G (mean changes generally less than 3% or about 0.5 cm). By contrast, Grassino et al. (J. Appl. Physiol. 39: 997-1003, 1975) found no change in the vertical distribution of ventilation after voluntarily changing lung dimensions by more than 1 cm by moving the abdomen in or out. We conclude that gravity produces the topographical distribution of ventilation in the upright human lung by distorting the elastic lung tissue within the chest rather than by altering the shape of the rib cage and diaphragm.

Optical grating evaluator: a device for detailed measurement of diffraction grating efficiencies in the vacuum ultraviolet.

A device for detailed measurement of diffraction grating efficiencies and over-all performance in the VUV has been designed and constructed at the Naval Research Laboratory. The system employs semiautomated mechanisms to scan the face of the grating with a narrow monochromatic beam, and an efficiency map of the grating surface is produced on a strip chart recorder. Grating efficiency in the various diffracted orders and intensity of light scattered between orders may also be measured. A unique feature is the ability to determine the angle and effectiveness of grating blaze and variations in blaze under different conditions of illumination.