Internal Delensing of Cosmic Microwave Background Polarization B-Modes with the POLARBEAR Experiment.

Using only cosmic microwave background polarization data from the polarbear experiment, we measure B-mode polarization delensing on subdegree scales at more than 5σ significance. We achieve a 14% B-mode power variance reduction, the highest to date for internal delensing, and improve this result to 22% by applying for the first time an iterative maximum a posteriori delensing method. Our analysis demonstrates the capability of internal delensing as a means of improving constraints on inflationary models, paving the way for the optimal analysis of next-generation primordial B-mode experiments.

Neonatal renal replacement therapy: An ethical reflection for a crucial decision.

CONTEXT: Technological advances in fetal and neonatal medicine, recent changes in the French legal framework, and encouraging results of the long-term outcomes in children with neonatal renal failure provide elements for an ethical reflection. METHODS: We led a nationwide enquiry among French pediatric nephrologists, intensivists, and neonatologists, exploring the decision-making process when contemplating starting renal replacement therapy (RRT) or delivering palliative care to neonates or infants with pre-end-stage or end-stage renal disease; and the ethical quandaries at hand in such scenarios. RESULTS: A total of 134 responses with complete national coverage were obtained. Care to be delivered to an infant in pre-end-stage or end-stage renal disease did not achieve consensus. Pediatric nephrologists were more prone to initiate a dialysis/graft program than pediatric intensivists. When chronic kidney disease was associated with comorbidities, especially neurological impairment, physicians, regardless of their subspecialty, were more reluctant to initiate conservative treatment. Many of the doctors surveyed did not give their opinion in these prenatal and/or postnatal situations, considered to be unique and warranting a multidisciplinary reflection. CONCLUSION: Such ethical dilemmas are challenging for parents and physicians. They can only be overcome by taking into account both concrete on the ground realities and general principles and values acknowledged to be a basis for respecting the individual. In this way, it ensures humaneness and humanization of a practice that must meet a variety of challenges, one by one. The answer is not simple; it is always unique to each child and can only be approached by a multidisciplinary, time-consuming, open discussion, which will never totally erase uncertainty.

Measurement of the cosmic microwave background polarization lensing power spectrum with the POLARBEAR experiment.

Gravitational lensing due to the large-scale distribution of matter in the cosmos distorts the primordial cosmic microwave background (CMB) and thereby induces new, small-scale B-mode polarization. This signal carries detailed information about the distribution of all the gravitating matter between the observer and CMB last scattering surface. We report the first direct evidence for polarization lensing based on purely CMB information, from using the four-point correlations of even- and odd-parity E- and B-mode polarization mapped over ∼30 square degrees of the sky measured by the POLARBEAR experiment. These data were analyzed using a blind analysis framework and checked for spurious systematic contamination using null tests and simulations. Evidence for the signal of polarization lensing and lensing B modes is found at 4.2σ (stat+sys) significance. The amplitude of matter fluctuations is measured with a precision of 27%, and is found to be consistent with the Lambda cold dark matter cosmological model. This measurement demonstrates a new technique, capable of mapping all gravitating matter in the Universe, sensitive to the sum of neutrino masses, and essential for cleaning the lensing B-mode signal in searches for primordial gravitational waves.

Evidence for gravitational lensing of the cosmic microwave background polarization from cross-correlation with the cosmic infrared background.

We reconstruct the gravitational lensing convergence signal from cosmic microwave background (CMB) polarization data taken by the Polarbear experiment and cross-correlate it with cosmic infrared background maps from the Herschel satellite. From the cross spectra, we obtain evidence for gravitational lensing of the CMB polarization at a statistical significance of 4.0σ and indication of the presence of a lensing B-mode signal at a significance of 2.3σ. We demonstrate that our results are not biased by instrumental and astrophysical systematic errors by performing null tests, checks with simulated and real data, and analytical calculations. This measurement of polarization lensing, made via the robust cross-correlation channel, not only reinforces POLARBEAR auto-correlation measurements, but also represents one of the early steps towards establishing CMB polarization lensing as a powerful new probe of cosmology and astrophysics.

Slewing Mirror Telescope optics for the early observation of UV/optical photons from Gamma-Ray Bursts.

We report on design, manufacture, and testing of a Slewing Mirror Telescope (SMT), the first of its kind and a part of Ultra-Fast Flash Observatory-pathfinder (UFFO-p) for space-based prompt measurement of early UV/optical light curves from Gamma-Ray Bursts (GRBs). Using a fast slewing mirror of 150 mm diameter mounted on a 2 axis gimbal stage, SMT can deliver the images of GRB optical counterparts to the intensified CCD detector within 1.5~1.8 s over ± 35 degrees in the slewing field of view. Its Ritchey-Chrétien telescope of 100 mm diameter provides a 17 × 17 arcmin² instantaneous field of view. Technical details of design, construction, the laboratory performance tests in space environments for this unique SMT are described in conjunction with the plan for in-orbit operation onboard the Lomonosov satellite in 2013.

Intranasal application of xenon: describing the pharmacokinetics in experimental animals and the increased pain tolerance within a placebo-controlled experimental human study.

BACKGROUND: Pain sensitizes the central nervous system via N-methyl-D-aspartate receptors (NMDARs) leading to an enhancement of pain perception. However, the enhanced responsiveness of pain-processing areas can be suppressed by subanaesthetic doses of the NMDAR antagonist xenon. To analyse the strength of the analgesic effect of low-dose xenon using new economical application methods, we tested xenon applied nasally in an experimental human pain setting. METHODS: We tested 10 healthy volunteers using a multimodal experimental pain testing in a randomized double-blind placebo-controlled repeated measures study. Xenon was administered using a novel low-pressure intranasal application device. Additionally, we measured xenon concentrations in blood samples obtained from intracranial veins of experimental animals to describe the pharmacokinetics of intranasally applied xenon in the cerebral compartment. RESULTS: Intranasal application of xenon at a rate of 1.0 litre h(-1) for 30 min significantly increased pain tolerance of volunteers to ischaemic (+128%), cold (+58%), and mechanical (+40%) stimulation (P<0.01). However, 60 min after terminating the application of xenon, there was no significant alteration of pain tolerance compared with placebo. Cranial blood concentrations of xenon in pigs reached a steady state of approximately 450 nl ml(-1) after 5 min. CONCLUSIONS: In this placebo-controlled experimental human study, we described the increased pain tolerance induced by intranasally applied xenon. On the basis of our results, we conclude that intranasally administered xenon has analgesic properties and suggest that the novel application device presented here offers new possibilities for the administration of NMDAR antagonists within a multimodal analgesia approach.

Effect of a xenograft on early bone formation in extraction sockets: an experimental study in dog.

AIM: The aim of this study was to study the effect on early bone formation resulting from the placement of a xenograft in the fresh extraction socket in dogs. MATERIAL AND METHODS: Five beagle dogs were used. The distal roots of the third and fourth mandibular premolars were removed. In one quadrant, a graft consisting of Bio-Oss Collagen was placed in the fresh extraction wound, while the corresponding premolar sites in the contra-lateral jaw quadrant were left non-grafted. After 2 weeks of healing, the dogs were perfused with a fixative, the mandibles removed, the experimental sites dissected, demineralized, sectioned in the mesio-distal plane and stained in hematoxyline-eosine. RESULTS: The central portion of the non-grafted sockets was occupied by a provisional matrix comprised of densely packed connective tissue fibers and mesenchymal cells. Apical and lateral to the provisional matrix, newly formed woven bone was found to occupy most of the sockets. In the apical part of the grafted sockets, no particles of the xenograft could be observed but newly formed bone was present in this portion of the experimental site. In addition, limited numbers of woven bone trabeculae occurred along the lateral socket walls. The central and marginal segments of the grafted sockets, however, were occupied by a non-mineralized connective tissue that enclosed Bio-Oss particles that frequently were coated by multinucleated cells. CONCLUSIONS: The placement of Bio-Oss Collagen in the fresh extraction wound obviously delayed socket healing. Thus, after 2 weeks of tissue repair, only minute amounts of newly formed bone occurred in the apical and lateral borders of the grafted sockets, while large amounts of woven bone had formed in most parts of the non-grafted sites.

Schistosoma mansoni: chemoreception through n-acetyl-d-galactosamine-containing receptors in females offers insight into increased severity of schistosomiasis in individuals with blood group A.

The role of exposed surface carbohydrates in chemoreception in Schistosoma mansoni females was investigated in vitro. Sexually mature females were treated with peanut (PNA), soybean (SBA) or wheat germ (WGA) agglutinin, and their migration in response to excretory-secretory (ES) products of males was measured in a bioassay system. Random distribution of untreated and lectin-treated females was similar (p=>0.05). PNA-treated females were unresponsive for 1.0 h, after which they exhibited slight repulsion to ES products. SBA-treated females did not respond to ES products for 3.0 h. WGA-treated females were unresponsive for 1.5h, after which they exhibited slight attraction to male ES products. Attempts were made to restore chemoattraction by using specific sugar inhibitors of lectin-binding; chemoattraction was best restored in n-acetyl-d-galactosamine (GalNAc)-treated females. These data suggest that GalNAc-containing receptors, possibly GP50, the major SBA-binding schistosome glycan, mediate chemoreception in schistosome females. These findings may explain the observed differences in morbidity between individuals with different blood groups. Individuals with blood group B or O may afford partial protection because of their natural anti-A or by mounting a more efficient antibody response directed against GalNAc-containing structures shared by blood group A red blood cells.

Soft tissue healing at titanium implants coated with type I collagen. An experimental study in dogs.

OBJECTIVE: To analyse the soft tissue healing at titanium implants coated with type 1 collagen. MATERIAL AND METHODS: Six dogs were used. The mandibular pre-molars and the three anterior maxillary pre-molars were extracted. Three months later mucoperiosteal flaps were raised and two test and two control implants were installed (3i TG Osseotite 3.75 x 10 and 2.8 mm transmucosal collar). The test implants were coated with a purified porcine type I collagen. Cover screws were placed and flaps were sutured. The sutures were removed 2 weeks later and a plaque-control programme was initiated. Another 2 weeks later, the procedure was repeated in the contra-lateral mandibular region. Four weeks after the second implant surgery, biopsies were obtained and prepared for histological examination. RESULTS/CONCLUSION: The vertical dimensions of the epithelial and connective tissue components as well as the composition of the connective tissue portion facing the implant were similar at collagen-coated and uncoated implants after 4 and 8 weeks of healing. It is suggested that soft tissue healing to implants coated with type I collagen was similar to that at non-coated titanium implants and that no adverse reactions to the collagen-coated implants occurred.

Immunoglobulin uptake and processing by Schistosoma mansoni.

Intravascular Schistosoma mansoni worms seem to take up immunoglobulins from blood by surface Fc-receptors, but the process whereby bound immunoglobulins are processed by the parasite is poorly understood. We here present morphological data suggesting that two distinct main processes are involved: Host immunoglobulins were seen at two distinct locations in the parasite: in the frontal part of the enteric tube, the oesophagus, and as a fine granular staining at the surface and in the subtegumental region. The latter staining pattern corresponds to host immunoglobulin localization in discrete organelle-like aggregates tentatively identified as 'discoid or elongate bodies' at the ultrastructural level using immunogold staining. Immunoglobulin uptake by intravascular worms was also demonstrated in vivo after passive administration of 125I-labelled rabbit and mouse immunoglobulins. Radiolabelled immunoglobulins were taken up by the worms and shown to localize as fine strands running perpendicular to the parasite surface. Our results suggest that intravascular schistosomes take up host immunoglobulins both as part of their enteric digestion and by a surface Fc-receptor-mediated mechanism, involving transport and processing within organelles, 'elongate bodies'. Immunoglobulins taken up by intravascular schistosomes form a distinct organelle-like granules, which seem to be processed within the excretory system of the parasite.

Thomsen-Friedenreich oncofetal antigen in Schistosoma mansoni : localization and immunogenicity in experimental mouse infection.

Our preliminary observation, that sera from schistosomiasis patients react with carcinomas, raised the possibility of antigenic cross-reactivity. We here extend this observation to show that mice experimentally infected with Schistosoma mansoni react with human urothelial and transitional bladder carcinomas and also with a gastric carcinoma cell line, AGS. To identify cross-reacting epitopes, we looked for the expression of carcinoma markers in schistosome worms and eggs using monoclonal antibodies against tumour antigens MUC1, Tn and TF (also known as the oncofetal Thomsen-Friedenreich antigen or T antigen). Immunohistochemical staining showed that the TF-epitope is present in adult intravascular S. mansoni worms and eggs deposited in tissues of infected animals. The localization of TF-immuno-reactive material in schistosomes was seen at the parasite surface between male and female worms and around trapped eggs in the liver. This localization is consistent with the antigen being secreted. Mice experimentally infected with S. mansoni, developed circulating antibodies against the TF-epitope (identified as Gal(beta1-3) GalNAc-O-R) as seen in ELISA using TF-expressing asialoglycophorin (AGP) as antigen. The observed anti-TF response in S. mansoni-infected mice reflects the complexity of host-parasite interactions in this infection.

Secretory antibodies against Giardia intestinalis in lactating Nicaraguan women.

Secretory IgA (sIgA) antibodies are important in the host defence against the intestinal protozoan parasite Giardia intestinalis. However, few antigens have been identified. In this study 100 milk and saliva samples from lactating women, living in an endemic region (León, Nicaragua), were screened for the presence of antibodies against G. intestinalis. Most milk and saliva samples contained anti-Giardia antibodies (59% and 52%, respectively), with a mean sIgA content 50 times higher in milk than in saliva. The positive samples reacted with trophozoite membrane, flagella and cytoplasmic antigens. Western blot analysis showed that milk and saliva anti-Giardia sIgA recognized up to 16 different Giardia proteins in the molecular weight region 20-165 kDa. Two-dimensional Western blotting showed that the major immunoreactive proteins were the same as the immunoreactive proteins identified by serum from acute giardiasis patients in a non-endemic country. The major difference was a stronger reactivity against the variant surface proteins (VSPs) in the milk samples. Milk sIgAs also recognized recombinant Giardia proteins such as alpha-1 giardin, ornithine carbamoyl transferase, VSP-4EX, arginine deaminase and alpha-enolase. These antigens will be important targets in the development of new immunodiagnostic tools and vaccines.

The mucosal attachment to titanium implants with different surface characteristics: an experimental study in dogs.

BACKGROUND: Findings from in vitro studies have indicated that the orientation and proliferation of cells on titanium surfaces may be influenced by the topography of the surface on which they are grown. It may be argued, therefore, that differences may occur in the mucosal attachment to titanium implants with different surface roughness. AIM: The present experiment was performed to study the composition of the soft tissue barrier that formed to implants prepared with well-defined smooth or rough surfaces. MATERIAL AND METHODS: Five beagle dogs were used. Four implants made of c.p. titanium were placed in the right edentulous mandibular premolar region. After 3 months, two different types of abutments were connected: one experimental (OA) with a dual, thermal acid-etched surface ('Osseotite'), and one regular (RA) abutment with a 'turned' surface. At the end of a 6-month period during which proper plaque control had been maintained, biopsies including the implant and the surrounding soft and hard tissues were obtained, decalcified and processed for light and electron microscopy. A confocal He-Ne laser profilometer was used to study the surface topography of the abutments. RESULTS: The attachment between the peri-implant mucosa and titanium abutments with either a turned (RA; 'smooth') or acid-etched (OA; 'rough') surface was similar from both a quantitative and a qualitative aspect. The attachment comprised a barrier epithelium and a zone of connective tissue attachment of similar dimension at RA and OA. It was further observed that the 'inner' zone of the connective tissue attachment at both types of abutment was composed of about 30-33% fibroblasts and 63-66% collagen. CONCLUSION: It was demonstrated that the soft tissue attachment that formed to implants made of c.p. titanium was not influenced by the roughness of the titanium surface.

Bacterial infections of free-living amoebae.

Free-living amoebae are a diverse group of ubiquitous unicellular organisms, some of which cause severe central nervous system infections and keratitis. However, the focus of research has shifted from the direct pathogenic effects of free-living amoebae towards their role as carriers of pathogenic bacteria. Large outbreaks of legionellosis with numerous fatal cases, both in hospitals and in the community, appear to be the visible tip of the iceberg of complex relationships between amoebae and bacteria in biofilms. The recognition of amoebae as reservoirs and vehicles for bacterial spread leads us to public health issues such as the development of pathogenicity, antibiotic resistance, quality of public water supplies, housing standards, sanitation and decontamination measures. In this review we discuss bacterial infections of free-living amoebae from both a "biological" and general "infection control" point of view.

Intestinal parasites in HIV-2 associated AIDS cases with chronic diarrhoea in Guinea-Bissau.

Previous studies from African countries where HIV-1 infection is prevalent have shown that infections with Cryptosporidium parvum, Isospora belli and microsporidia are frequently associated with chronic diarrhoea in AIDS patients. The information about the occurrence of these parasites in HIV-2 associated AIDS cases with chronic diarrhoea is limited. We have performed a study of stool parasites in patients from Guinea-Bissau, the country with the highest prevalence of HIV-2 in the world. Stool specimens from 52 adult patients with chronic diarrhoea of which 37 were HIV-positive and fulfilling the clinical criteria of AIDS (five HIV-1, 28 HIV-2 and four dually infected with HIV-1 and HIV-2) were screened for parasitic infections. Twenty five percent of the HIV-2 positive patients were infected with C. parvum, 11% with I. belli and 11% with microsporidia, all three parasites were seen only in HIV-positive patients. The three patients with microsporidiosis, all HIV-2 infected, are to our knowledge the first cases reported from Guinea-Bissau. Other stool parasites such as Blastocystis hominis, hookworm and Strongyloides stercoralis were observed both among HIV-positive and HIV-negative patients.

Specific detection of Entamoeba histolytica DNA by hemolysin gene targeted PCR.

Diagnostic differentiation of pathogenic Entamoeba histolytica from non-pathogenic Entamoeba dispar is of great clinical importance. We have developed and evaluated a new polymerase chain reaction (PCR) assay (haemo-PCR) based on the novel E. histolytica hemolysin gene HLY6. The specificity of this assay was confirmed by analyzing different Entamoeba species, faeces samples, human and bacterial DNA, and digestion of amplification products with appropriate restriction enzymes. The sensitivity was confirmed by serial dilutions of E. histolytica HM-1:IMSS DNA in the excess of human DNA. Totally, 45 clinical samples were analyzed by the haemo-PCR assay including amoebic liver abscess (ALA) fluids from 23 patients suspected for amoebiasis, four faeces samples containing E. histolytica and E. dispar, and positive and negative controls. The results were compared with those obtained with PCRs for cystein-rich surface protein (P30) and small subunit ribosomal RNA (ssu rRNA) genes. The haemo-PCR gave a positive result in 18 (89%) ALA fluids compared with 14 (77%) and five (28%) by PCR for p30, and ssu rRNA, respectively. PCR products were obtained only from specimens containing E. histolytica DNA. The haemo-PCR assay was therefore found to be a valuable diagnostic tool for identification of E. histolytica infections both in faeces and ALA samples.

Negatively charged quantum well polaritons in a GaAs/AlAs microcavity: An analog of atoms in a cavity

The negatively charged exciton (X-) is observed to strongly couple with the microcavity- (MC-)confined photons in a GaAs quantum well containing a two-dimensional electron gas with 0

The barrier between the keratinized mucosa and the dental implant. An experimental study in the dog.

The present study was performed in order to examine the composition of the connective tissue that forms an attachment to a dental implant. 6 beagle dogs were used. All mandibular premolars were extracted. After 3 months of healing, 6 fixtures--3 in each side of the mandible--(Astra Tech Implants, Dental System TiO blast; Astra Tech AB, Mölndal, Sweden) were installed. After another 3 months of healing, abutment (Uni-abutment 45; Astra Tech AB, Mölndal, Sweden) connection was performed and a plaque control program was initiated. The animals were sacrificed and perfused with a fixative through the carotid arteries. Each implant site, including the implant and the soft and hard peri-implant tissues, was dissected, decalcified in EDTA and further processed using a "fracture technique". The specimens were subsequently embedded in EPON, cut with the microtome set at 3 microm and the sections stained in PAS and toluidine blue. From the EPON-embedded blocks, ultra-thin sections were cut and electron micrographs were prepared. The detailed histologic and morphometrical examinations were restricted to a 200 microm wide zone of connective tissue interposed between the apical border of the junctional epithelium and the bone tissue. In the analysis, this zone was further subdivided into 2 different units; (i) one central, 40 microm wide unit (zone A) located immediately next to the implant surface, and (ii) one lateral, 160 microm wide unit (zone B) that was continuous with the central unit. The implant surface apical of the junctional epithelium and coronal of the bone crest appeared to be in direct contact with a connective tissue. Zone A of this connective tissue was characterized by its (i) absence of blood vessels and (ii) abundance of fibroblasts which were interposed between thin collagen fibers. The more lateral zone B contained comparatively fewer fibroblasts, but more collagen fibers and blood vessels. There are reasons to assume that the fibroblast rich barrier tissue next to the titanium surface plays a rôle in the maintenance of a proper seal between the oral environment and the peri-implant bone.

Free-living amoebae protecting Legionella in water: the tip of an iceberg?

Bacteria are a main food source for free-living amoebae inhabiting aquatic systems. Some bacteria however, have the ability to prevent intracellular destruction and can survive and grow in amoebic cells as endosymbionts. Free-living amoebae are well adapted to their hostile environmental conditions and are resistant to both desiccation, elevated temperatures and various disinfectants. For their endosymbionts, amoebae represent perfect vectors, providing both protection against adverse environmental conditions and transportation. There is increasing interest in the potential role of free-living amoebae as reservoirs and vectors of pathogenic bacteria. The best known of such pathogenic bacteria is Legionella, and several studies provide evidence for the importance of the amoeba-bacterium relationship in the biology and epidemiology of pneumonia caused by this pathogen. Although the relative importance of endosymbiosis of this kind is unknown when it comes to other human bacterial infections and the exact role of amoebic hosts in bacterial survival, multiplication and transmission in the environment is still poorly understood, naming free-living amoebae the "Trojan horses" of the microbial world is appropriate.