Broadband squeezing of quantum noise in a Michelson interferometer with Twin-Signal-Recycling

Twin-Signal-Recycling (TSR) builds on the resonance doublet of two optically coupled cavities and efficiently enhances the sensitivity of an interferometer at a dedicated signal frequency. We report on the first experimental realization of a Twin-Signal-Recycling Michelson interferometer and also its broadband enhancement by squeezed light injection. The complete setup was stably locked and a broadband quantum noise reduction of the interferometers shot noise by a factor of up to 4\,dB was demonstrated. The system was characterized by measuring its quantum noise spectra for several tunings of the TSR cavities. We found good agreement between the experimental results and numerical simulations

CalDAG-GEFI deficiency protects mice in a novel model of FcγRIIA-mediated thrombosis and thrombocytopenia

Platelet activation via Fcγ receptor IIA (FcγRIIA) is a critical event in immune-mediated thrombocytopenia and thrombosis syndromes (ITT). We recently identified signaling by the guanine nucleotide exchange factor CalDAG-GEFI and the adenosine diphosphate receptor P2Y12 as independent pathways leading to Rap1 small GTPase activation and platelet aggregation. Here, we evaluated the contribution of CalDAG-GEFI and P2Y12 signaling to platelet activation in ITT. Mice transgenic for the human FcγRIIA (hFcR) and deficient in CalDAG-GEFI(−/−) (hFcR/CDGI(−/−)) were generated. Compared with controls, aggregation of hFcR/CDGI(−/−) platelets or P2Y12 inhibitor-treated hFcR platelets required more than 5-fold and approximately 2-fold higher concentrations of a FcγRIIA stimulating antibody against CD9, respectively. Aggregation and Rap1 activation were abolished in P2Y12 inhibitor-treated hFcR/CDGI(−/−) platelets. For in vivo studies, a novel model for antibody-induced thrombocytopenia and thrombosis was established. FcγRIIA-dependent platelet thrombosis was induced by infusion of Alexa750-labeled antibodies to glycoprotein IX (CD42a), and pulmonary thrombi were detected by near-infrared imaging technology. Anti-GPIX antibodies dose-dependently caused thrombocytopenia and pulmonary thrombosis in hFcR-transgenic but not wild-type mice. CalDAG-GEFI-deficient but not clopidogrel-treated hFcR-transgenic mice were completely protected from ITT. In summary, we established a novel mouse model for ITT, which was used to identify CalDAG-GEFI as a potential new target in the treatment of ITT

Modelling malaria pathogenesis

Almost 20 years after the development of models of malaria pathogenesis began, we are beyond the ‘proof-of-concept’ phase and these models are no longer abstract mathematical exercises. They have refined our knowledge of within-host processes, and have brought insights that could not easily have been obtained from experimentation alone. There is much potential that remains to be realized, however, both in terms of informing the design of interventions and health policy, and in terms of addressing lingering questions about the basic biology of malaria. Recent research has begun to iterate theory and data in a much more comprehensive way, and the use of statistical techniques for model fitting and comparison offers a promising approach for providing a quantitative understanding of the pathogenesis of such a complex disease

Connaissances des Anomalies du Tube Neural, Attitudes et Pratiques de Prévention chez les Femmes vues en Consultation prénatale, Région de Niamey-Niger, 2017: Knowledge, Attitudes and Prevention Practices of Neural Tube Anomalies in Women attending Prenatal Consultation in the Niamey-Niger Region 2017

Introduction: Les anomalies congénitales sont des anomalies fonctionnelles, structurelles ou métaboliques se produisant en intra-utérin et identifiables avant ou après la naissance. Au Niger, le domaine des anomalies congénitales n'a pas été suffisamment exploré. Notre objectif était de décrire les connaissances des anomalies du tube neural (ATN), les attitudes et les pratiques de prévention chez les femmes vues en consultation prénatale (CPN). Méthodes: Nous avons mené une enquête transversale de Février â Mars 2017 chez les femmes enceintes vues en CPN1 dans les maternités de Niamey. L'échantillon, calculé avec Open Epi était de 421. Les femmes enceintes ont été interviewées sur leurs connaissances des ATN, leurs attitudes et pratiques de prévention devant ces anomalies. Les données ont été collectées avec un questionnaire à travers les 5 districts sanitaires de la region de Niamey. Le nombre de femmes à enquêter par district a été alloué en tenant compte de l'importance relative des femmes en age de procréer (FAP) selon le district. Dans chaque district, il a été choisi par commodité, l'hôpital de district (HD), 2 maternités urbaines et 2 maternités rurales. Le nombre de femme par maternité a été déterminé selon le même procédé que dans les districts. A la maternité, les participantes ont été choisi de manière aléatoire. Des analyses univariées, bivariées et multivariées ont été réalisées. Des ratios de prévalence (RP), OR de prévalence (POR) à 95% ont été calculés. Les variables avec p<0,25 en analyse bivariée, ont été intégrées dans le modèle logistique multiple. Résultats: L'âge médian des enquêtées était de 25 ans. Il y avait 60,81% de scolarisées et 24,33% de primigestes. Environ 30,65% connaissaient les ATN ; 15,92% avaient de bonnes attitudes ; 41,81% avaient utilisées l'acide folique (AF). La tranche d'êge de 25-49ans a été un facteur indépendant de la connaissance des ATN (p=0,0008) ; pour les attitudes : il s'agit de l'âge (25-49ans) (p=0,03), la prise d'AF (p=0,0002) ; pour la pratique : le niveau d'instruction (p=0,01), l'information par les agents de santé (p< 0,0001), la connaissance d'autres sources d'AF (p=0,04). Conclusion: Il y avait une insuffisance de connaissances, d'attitudes et de pratiques de prévention devant les ATN chez les femmes enceintes. L'éducation continue, une politique d'enrichissement en AF de certains aliments s'impose. Background: Congenital anomalies are functional, structural or metabolic abnormalities occurring in the uterus and identifiable before or after birth. In Niger, the field of congenital anomalies has not been sufficiently explored. Our objective was to describe the knowledge of neural tube defects (NTDs), attitudes and prevention practices in women seen in antenatal care (ANC). Methods: We conducted a cross-sectional survey from February to March 2017 among pregnant women seen in CPN1 in maternity hospitals in Niamey. The sample, calculated with Open Epi, was 421. Pregnant women were interviewed on their knowledge of NTDs, their attitudes and prevention practices in the face of these anomalies. The data were collected with a questionnaire across the 5 health districts of the Niamey region. The number of women to be surveyed by district was allocated taking into account the relative importance of women of reproductive age (FAP) by district. In each district, it was chosen by convenience, the district hospital (HD), 2 urban maternities and 2 rural maternities. The number of women per maternity unit was determined using the same procedure as in the districts. In the maternity ward, the participants were chosen at random. Univariate, bivariate and multivariate analyzes were performed. 95% prevalence (PR), OR prevalence (POR) ratios were calculated. Variables with p <0.25 in bivariate analysis were included in the multiple logistic model. Results: The median age of the respondents was 25 years. There were 60.81% of school children and 24.33% of primigravidae. About 30.65% were familiar with ATNs; 15.92% had good attitudes; 41.81% had used folic acid (FA). The age group of 25-49 years was an independent factor of knowledge of NTDs (p = 0.0008); for attitudes: it is about age (25-49 years) (p = 0.03), AF intake (p = 0.0002); for practice: level of education (p = 0.01), information by health workers (p <0.0001), knowledge of other sources of FA (p = 0.04). Conclusion: There was a lack of knowledge, attitudes and prevention practices towards NTDs among pregnant women. Education continues, a policy of fortifying certain foods with AF is required

Heat Conduction in κ\kappa-(BEDT-TTF)2_2Cu(NCS)2_2

The first study of thermal conductivity, $\kappa$, in a quasi-two-dimensional organic superconductor of the $\kappa$-(BEDT-TTF)$_2$X family reveals features analogous to those already observed in the cuprates. The onset of superconductivity is associated with a sudden increase in $\kappa$ which can be suppressed by the application of a moderate magnetic field. At low temperatures, a finite linear term - due to a residual electronic contribution- was resolved. The magnitude of this term is close to what is predicted by the theory of transport in unconventional superconductors.Comment: 5 pages, 4 figures include

Etiology and risk factors for meningitis during an outbreak in Batié Health District, Burkina Faso, January-March 2016

Introduction: On 16 March 2016, Batié Health District notified the Burkina Faso Ministry of Health Surveillance unit of 12 suspected cases of meningitis. During the same period, Batié´s neighboring districts in Côte d'Ivoire and Ghana were experiencing a meningitis epidemic. We investigated to establish the etiology and risk factors for the disease and to recommend prevention and control measures. Methods: We conducted unmatched case control study. A case was any person living in Batié with fever (temp. ≥ 38.5°C) and any of the following: neck stiffness, neurological disorder, bulging fontanelle, convulsion during January to April 2016 with cerebrospinal fluid (CSF) positive to PCR. Controls were non sick household members, neighbors or friends to the cases. We analyzed the investigation and laboratory records. We included all confirmed cases and two neighborhood controls per case. We used a standard questionnaire to collect data. We analyzed data by Epi info 7 and calculated odds ratio (ORs),adjusted odds ratios (AOR) and 95% confidence interval. We proceeded to univariate, bivariate, multivariate and logistic regression analysis. Results: We interviewed 93 participants including 31 meningitis cases and 62 controls. The median age of cases was 8 years old [2 months-55 years] and 6.5 years old [5 months-51 years] for controls. Streptococcus pneumoniae 16(51.61%), Neisseria meningitidis W 14(45.16%) and Haemophilus influenzae b 1(3.23%) were the identified germs. The independent risk factors identified were travel to meningitis affected areas (Adjusted odd ratio(AOR)=12[2.3-60],p=0.0029); >5 persons sharing bedroom (AOR=5.7[1.5-22],p=0.012) and rhinopharyngitis (AOR=26[1.8-380],p=0.017). Conclusion: Streptococcus pneumoniae and Neisseria meningitidis W caused the outbreak in Batié. The risk factors were overcrowding, travel to affected areas, and rhinopharyngitis. We recommended reactive vaccination against Neisseria meningitidis W, limited travel to affected areas and ventilation of rooms

Identifying factors likely to influence compliance with diagnostic imaging guideline recommendations for spine disorders among chiropractors in North America: a focus group study using the Theoretical Domains Framework

Background: The Theoretical Domains Framework (TDF) was developed to investigate determinants of specific clinical behaviors and inform the design of interventions to change professional behavior. This framework was used to explore the beliefs of chiropractors in an American Provider Network and two Canadian provinces about their adherence to evidence-based recommendations for spine radiography for uncomplicated back pain. The primary objective of the study was to identify chiropractors’ beliefs about managing uncomplicated back pain without xrays and to explore barriers and facilitators to implementing evidence-based recommendations on lumbar spine xrays. A secondary objective was to compare chiropractors in the United States and Canada on their beliefs regarding the use of spine x-rays. Methods: Six focus groups exploring beliefs about managing back pain without x-rays were conducted with a purposive sample. The interview guide was based upon the TDF. Focus groups were digitally recorded, transcribed verbatim, and analyzed by two independent assessors using thematic content analysis based on the TDF. Results: Five domains were identified as likely relevant. Key beliefs within these domains included the following: conflicting comments about the potential consequences of not ordering x-rays (risk of missing a pathology, avoiding adverse treatment effects, risks of litigation, determining the treatment plan, and using x-ray-driven techniques contrasted with perceived benefits of minimizing patient radiation exposure and reducing costs; beliefs about consequences); beliefs regarding professional autonomy, professional credibility, lack of standardization, and agreement with guidelines widely varied (social/professional role & identity); the influence of formal training, colleagues, and patients also appeared to be important factors (social influences); conflicting comments regarding levels of confidence and comfort in managing patients without x-rays (belief about capabilities); and guideline awareness and agreements (knowledge). Conclusions: Chiropractors’ use of diagnostic imaging appears to be influenced by a number of factors. Five key domains may be important considering the presence of conflicting beliefs, evidence of strong beliefs likely to impact the behavior of interest, and high frequency of beliefs. The results will inform the development of a theorybased survey to help identify potential targets for behavioral-change strategies

Biological Sensors for Solar Ultraviolet Radiation

Solar ultraviolet (UV) radiation is widely known as a genotoxic environmental agent that affects Earth ecosystems and the human population. As a primary consequence of the stratospheric ozone layer depletion observed over the last decades, the increasing UV incidence levels have heightened the concern regarding deleterious consequences affecting both the biosphere and humans, thereby leading to an increase in scientific efforts to understand the role of sunlight in the induction of DNA damage, mutagenesis, and cell death. In fact, the various UV-wavelengths evoke characteristic biological impacts that greatly depend on light absorption of biomolecules, especially DNA, in living organisms, thereby justifying the increasing importance of developing biological sensors for monitoring the harmful impact of solar UV radiation under various environmental conditions. In this review, several types of biosensors proposed for laboratory and field application, that measure the biological effects of the UV component of sunlight, are described. Basically, the applicability of sensors based on DNA, bacteria or even mammalian cells are presented and compared. Data are also presented showing that on using DNA-based sensors, the various types of damage produced differ when this molecule is exposed in either an aqueous buffer or a dry solution. Apart from the data thus generated, the development of novel biosensors could help in evaluating the biological effects of sunlight on the environment. They also emerge as alternative tools for using live animals in the search for protective sunscreen products

Multiplicity of Plasmodium falciparum infection in asymptomatic children in Senegal: relation to transmission, age and erythrocyte variants

<p>Abstract</p> <p>Background</p> <p>Individuals living in malaria endemic areas generally harbour multiple parasite strains. Multiplicity of infection (MOI) can be an indicator of immune status. However, whether this is good or bad for the development of immunity to malaria, is still a matter of debate. This study aimed to examine the MOI in asymptomatic children between two and ten years of age and to relate it to erythrocyte variants, clinical attacks, transmission levels and other parasitological indexes.</p> <p>Methods</p> <p>Study took place in Niakhar area in Senegal, where malaria is mesoendemic and seasonal. Three hundred and seventy two asymptomatic children were included. Sickle-cell trait, G6PD deficiency (A- and Santamaria) and α⁺-thalassaemia (-α^3.7type) were determined using PCR. Multiplicity of <it>Plasmodium falciparum </it>infection, i.e. number of concurrent clones, was defined by PCR-based genotyping of the merozoite surface protein-2 (<it>msp2</it>), before and at the end of the malaria transmission season. The χ²-test, ANOVA, multivariate linear regression and logistic regression statistical tests were used for data analysis.</p> <p>Results</p> <p>MOI was significantly higher at the end of transmission season. The majority of PCR positive subjects had multiple infections at both time points (64% before and 87% after the transmission season). MOI did not increase in α-thalassaemic and G6PD mutated children. The ABO system and HbAS did not affect MOI at any time points. No association between MOI and clinical attack was observed. MOI did not vary over age at any time points. There was a significant correlation between MOI and parasite density, as the higher parasite counts increases the probability of having multiple infections.</p> <p>Conclusion</p> <p>Taken together our data revealed that α-thalassaemia may have a role in protection against certain parasite strains. The protection against the increase in MOI after the transmission season conferred by G6PD deficiency is probably due to clearance of the malaria parasite at early stages of infection. The ABO system and HbAS are involved in the severity of the disease but do not affect asymptomatic infections. MOI was not age-dependent, in the range of two to ten years, but was correlated with parasite density. However some of these observations need to be confirmed including larger sample size with broader age range and using other <it>msp2 </it>genotyping method.</p