Thermal noise in interferometric gravitational wave detectors due to dielectric optical coatings

We report on thermal noise from the internal friction of dielectric coatings made from alternating layers of Ta2O5 and SiO2 deposited on fused silica substrates. We present calculations of the thermal noise in gravitational wave interferometers due to optical coatings, when the material properties of the coating are different from those of the substrate and the mechanical loss angle in the coating is anisotropic. The loss angle in the coatings for strains parallel to the substrate surface was determined from ringdown experiments. We measured the mechanical quality factor of three fused silica samples with coatings deposited on them. The loss angle of the coating material for strains parallel to the coated surface was found to be (4.2 +- 0.3)*10^(-4) for coatings deposited on commercially polished slides and (1.0 +- 0.3)*10^{-4} for a coating deposited on a superpolished disk. Using these numbers, we estimate the effect of coatings on thermal noise in the initial LIGO and advanced LIGO interferometers. We also find that the corresponding prediction for thermal noise in the 40 m LIGO prototype at Caltech is consistent with the noise data. These results are complemented by results for a different type of coating, presented in a companion paper.Comment: Submitted to LSC (internal) review Sept. 20, 2001. To be submitted to Phys. Lett.

Foot-and-mouth disease in red deer - experimental infection and test methods performance

The aim of this study was to evaluate a number of foot-and-mouth disease (FMD) test methods for use in red deer. Ten animals were intranasally inoculated with the FMD virus (FMDV) O UKG 11/2001, monitored for clinical signs, and samples taken regularly (blood, serum, oral swabs, nasal swabs, probang samples and lesion swabs, if present) over a 4-week period. Only one animal, deer 1103, developed clinical signs (lesions under the tongue and at the coronary band of the right hind hoof). It tested positive by 3D and IRES real-time reverse transcription polymerase chain reaction (rRT-PCR) in various swabs, lesion materials and serum. In a non-structural protein (NSP) in-house ELISA (NSP-ELISA-IH), one commercial ELISA (NSP-ELISA-PR) and a commercial antibody NSP pen side test, only deer 1103 showed positive results from day post-inoculation (dpi) 14 onwards. Two other NSP-ELISAs detected anti-NSP serum antibodies with lower sensitivity. It also showed rising antibody levels in the virus neutralization test (VNT), the in-house SPO-ELISA-IH and the commercial SPO-ELISA-PR at dpi 9, and in another two commercial SPO-ELISAs at dpi 12 (SPO-ELISA-IV) and dpi 19 (SPO-ELISA-IZ), respectively. Six of the red deer that had been rRT-PCR and antibody negative were re-inoculated intramuscularly with the same O-serotype FMDV at dpi 14. None of these animals became rRT-PCR or NSP-ELISA positive, but all six animals became positive in the VNT, the in-house SPO-ELISA-IH and the commercial SPO-ELISA-PR. Two other commercial SPO-ELISAs were less sensitive or failed to detect animals as positive. The rRT-PCRs and the four most sensitive commercial ELISAs that had been used for the experimentally inoculated deer were further evaluated for diagnostic specificity (DSP) using 950 serum samples and 200 nasal swabs from non-infected animals. DSPs were 100% for the rRT-PCRs and between 99.8 and 100% for the ELISAs

Horizontally acquired glycosyltransferase operons drive salmonellae lipopolysaccharide diversity.

The immunodominant lipopolysaccharide is a key antigenic factor for Gram-negative pathogens such as salmonellae where it plays key roles in host adaptation, virulence, immune evasion, and persistence. Variation in the lipopolysaccharide is also the major differentiating factor that is used to classify Salmonella into over 2600 serovars as part of the Kaufmann-White scheme. While lipopolysaccharide diversity is generally associated with sequence variation in the lipopolysaccharide biosynthesis operon, extraneous genetic factors such as those encoded by the glucosyltransferase (gtr) operons provide further structural heterogeneity by adding additional sugars onto the O-antigen component of the lipopolysaccharide. Here we identify and examine the O-antigen modifying glucosyltransferase genes from the genomes of Salmonella enterica and Salmonella bongori serovars. We show that Salmonella generally carries between 1 and 4 gtr operons that we have classified into 10 families on the basis of gtrC sequence with apparent O-antigen modification detected for five of these families. The gtr operons localize to bacteriophage-associated genomic regions and exhibit a dynamic evolutionary history driven by recombination and gene shuffling events leading to new gene combinations. Furthermore, evidence of Dam- and OxyR-dependent phase variation of gtr gene expression was identified within eight gtr families. Thus, as O-antigen modification generates significant intra- and inter-strain phenotypic diversity, gtr-mediated modification is fundamental in assessing Salmonella strain variability. This will inform appropriate vaccine and diagnostic approaches, in addition to contributing to our understanding of host-pathogen interactions

Interaction of microtubules and actin during the post-fusion phase of exocytosis

Exocytosis is the intracellular trafficking step where a secretory vesicle fuses with the plasma membrane to release vesicle content. Actin and microtubules both play a role in exocytosis; however, their interplay is not understood. Here we study the interaction of actin and microtubules during exocytosis in lung alveolar type II (ATII) cells that secrete surfactant from large secretory vesicles. Surfactant extrusion is facilitated by an actin coat that forms on the vesicle shortly after fusion pore opening. Actin coat compression allows hydrophobic surfactant to be released from the vesicle. We show that microtubules are localized close to actin coats and stay close to the coats during their compression. Inhibition of microtubule polymerization by colchicine and nocodazole affected the kinetics of actin coat formation and the extent of actin polymerisation on fused vesicles. In addition, microtubule and actin cross-linking protein IQGAP1 localized to fused secretory vesicles and IQGAP1 silencing influenced actin polymerisation after vesicle fusion. This study demonstrates that microtubules can influence actin coat formation and actin polymerization on secretory vesicles during exocytosis

Spatial distribution and risk factors of Brucellosis in Iberian wild ungulates

<p>Abstract</p> <p>Background</p> <p>The role of wildlife as a brucellosis reservoir for humans and domestic livestock remains to be properly established. The aim of this work was to determine the aetiology, apparent prevalence, spatial distribution and risk factors for brucellosis transmission in several Iberian wild ungulates.</p> <p>Methods</p> <p>A multi-species indirect immunosorbent assay (iELISA) using <it>Brucella </it>S-LPS antigen was developed. In several regions having brucellosis in livestock, individual serum samples were taken between 1999 and 2009 from 2,579 wild bovids, 6,448 wild cervids and4,454 Eurasian wild boar (<it>Sus scrofa</it>), and tested to assess brucellosis apparent prevalence. Strains isolated from wild boar were characterized to identify the presence of markers shared with the strains isolated from domestic pigs.</p> <p>Results</p> <p>Mean apparent prevalence below 0.5% was identified in chamois (<it>Rupicapra pyrenaica</it>), Iberian wild goat (<it>Capra pyrenaica</it>), and red deer (<it>Cervus elaphus</it>). Roe deer (<it>Capreolus capreolus</it>), fallow deer (<it>Dama dama</it>), mouflon (<it>Ovis aries</it>) and Barbary sheep (<it>Ammotragus lervia</it>) tested were seronegative. Only one red deer and one Iberian wild goat resulted positive in culture, isolating <it>B. abortus </it>biovar 1 and <it>B. melitensis </it>biovar 1, respectively. Apparent prevalence in wild boar ranged from 25% to 46% in the different regions studied, with the highest figures detected in South-Central Spain. The probability of wild boar being positive in the iELISA was also affected by age, age-by-sex interaction, sampling month, and the density of outdoor domestic pigs. A total of 104 bacterial isolates were obtained from wild boar, being all identified as <it>B. suis </it>biovar 2. DNA polymorphisms were similar to those found in domestic pigs.</p> <p>Conclusions</p> <p>In conclusion, brucellosis in wild boar is widespread in the Iberian Peninsula, thus representing an important threat for domestic pigs. By contrast, wild ruminants were not identified as a significant brucellosis reservoir for livestock.</p

Fall bird migration in western North America during a period of heightened wildfire activity

Billions of birds annually migrate between breeding and nonbreeding grounds in North America. During fall 2020, there was a series of alarming mass-mortality events of migratory birds across the western United States, with estimates of 100,000 to 1 million birds having perished. One potential culprit behind these die-offs is wildfires, though there has been little research documenting the indirect effects of wildfires on actively migrating birds. We undertook a multi-year assessment of potential impacts that wildfires may have had on fall bird migration over the past decade, with a particular focus on fall 2020, using systematic bird banding data from southeastern Utah. We used a correlative approach to evaluate the relationship between estimates of acres burned by wildfires in western North America on several variables representing bird abundance and body condition. Notably, in our best fit models of birds banded at our research site during fall 2020, we found both a positive relationship for the number of bird captures and a negative relationship for body mass index with more daily burned acres. We provide an examination of incorporating lag effects of wildfires on different metrics of bird migration to account for potential impacts of fires on birds before migration and banding. Additionally, we assess the usefulness of different proxies of body condition in highly stressed land birds and introduce a scale for scoring emaciation of birds in the hand while banding. Our insights into avian migration ecology are one of the few studies that explore the role wildfires may have had in affecting migratory bird movements and health

Melanocortin Receptor Agonists Facilitate Oxytocin-Dependent Partner Preference Formation in the Prairie Vole

The central melanocortin (MC) system has been widely studied for its effects on food intake and sexual behavior. However, the MC system, and more specifically the MC4 receptor (MC4R), also interacts with neurochemical systems that regulate socioemotional behaviors, including oxytocin (OT) and dopamine. In monogamous prairie voles, OT and dopamine interact to promote partner preference formation, a laboratory measure of an enduring social bond between mates. Here we investigated the effects of MC receptor activation on partner preference formation in prairie voles, as well as the interaction between the MC and OT systems during this process. Peripheral administration of the brain penetrant MC3/4R receptor peptide agonist, Melanotan II (MTII), and the highly selective, small-molecule MC4R agonist, Pf-446687, enhanced partner preference formation in the prairie vole, but not in the non-monogamous meadow vole. MTII-induced partner preferences were enduring, as they were present 1 week after drug manipulation. The prosocial effects of MCR agonists may be mediated, in part, through modulation of OT, as coadministration of an OT receptor antagonist prevented MTII-induced partner preferences. MTII also selectively activated hypothalamic OT neurons and potentiated central OT release. As OT has been shown to enhance some aspects of social cognition in humans, our data suggest that the MC4R may be a viable therapeutic target for enhancing social function in psychiatric disorders, including autism spectrum disorders and schizophrenia, potentially through activation of the OT system

Comparison of the q-fever complement fixation test and two commercial enzyme-linked immunosorbent assays for the detection of serum antibodies against coxiella burnetii (Q-fever) in ruminants: Recommendations for use of serological tests on imported animals in New Zealand

AIM: To make valid recommendations on the use of serological test methods for the detection of serum antibodies in ruminants against Coxiella burnetii (Q-fever), by comparing the performance of the complement fixation test (CFT) and two ELISA, and by identifying reasons for discrepancies between the test methods. METHODS: A total of 73 serum samples from infected cattle, 69 from infected goats, and 100 samples from non-infected cattle and 57 samples from non-infected sheep, as well as 95 samples from infected cattle herds (mix of seropositive and seronegative samples), were tested using the CFT, the IDEXX ELISA (I-ELISA) and the Pourquier ELISA (P-ELISA). A mixed panel of 12 serum samples from sheep from inter-laboratory proficiency testing (proficiency panel) was also tested using the CFT and both ELISA, and further investigated using IgG- and IgM-specific ELISA. RESULTS: Generally, the two commercial ELISA were more sensitive than the CFT for the detection of infected ruminants. Good agreement between ELISA for positive and negative results was found for samples from the infected herd, while results for the positive panels varied between the two ELISA. For the total of the positive serum panels, the I-ELISA detected 95% of samples as positive or suspicious, while the P-ELISA detected only 81%. In the P-ELISA, more samples were considered suspicious (18%) than in the I-ELISA (14%). All sera from noninfected sheep and cattle tested negative in the serological test methods employed, except for one positive sample from a sheep in the P-ELISA. Further investigation revealed that a CFT-positive but ELISA-negative result was due to high IgM and low IgG reactivity. CONCLUSIONS: The two commercial ELISA were more sensitive than the CFT in all panels from infected ruminants. However, they could only detect IgG. The I-ELISA should be the serological test method of choice for cattle, sheep and goats for import testing of animals into New Zealand because it was more sensitive than the P-ELISA and was equally specific to the PELISA and the CFT. For other animal species, such as deer and camelids, the CFT should still be used since none of the ELISA has been evaluated for these species. This study has shown that the two commercial ELISA will detect the majority of infected ruminants but may miss animals that have not developed an IgG response