Scattering of a Light Beam from Waves at an Air-Sea Interface

The authors report a new theory that describes the scattering of an upward propagating laser beam from the sea through the air-sea interface in the presence of sea waves. The sea is assumed to be a uniform dielectric and conventional scattering theory is employed by using a modification to the first Born approximation that permits treatment of surface refraction phenomena. Methods of statistical radiometry are also used in a new manner by assuming that the surface scattering function for the sea waves can be treated by a quasi-homogeneous source model to calculate the second-order correlation functions for the partially coherent scattered field. These correlation functions yield a simple expression for the radiant intensity of the scattered field as the convolution of the Fourier transform of the complex degree of spectral coherence for the sea waves with the squared modulus of the angular spectrum of plane waves for the incident laser beam. We believe that this theory is a significant improvement over the models that are usually used for modeling this phenomenon

Cooling of Hybrid Neutron Stars and Hypothetical Self-bound Objects with Superconducting Quark Cores

We study the consequences of superconducting quark cores (with color-flavor-locked phase as representative example) for evolution of temperature profiles and the cooling curves in quark-hadron hybrid stars and in hypothetical self-bounded objects having no a hadron shell (quark core neutron stars). The quark gaps are varied from 0 to $\Delta_q =50$ MeV. For hybrid stars we find time scales of $1\div5$, $5\div10$ and $50\div100$ years for the formation of a quasistationary temperature distribution in the cases $\Delta_q =0$, 0.1 MeV and \gsim 1 MeV, respectively. These time scales are governed by the heat transport within quark cores for large diquark gaps (\Delta \gsim 1 MeV) and within the hadron shell for small diquark gaps (\Delta \lsim 0.1 MeV). For quark core neutron stars we find a time scale $\simeq 300$ years for the formation of a quasistationary temperature distribution in the case \Delta \gsim 10 MeV and a very short one for \Delta \lsim 1 MeV. If hot young compact objects will be observed they can be interpreted as manifestation of large gap color superconductivity. Depending on the size of the pairing gaps, the compact star takes different paths in the ${lg}T_s$ vs. ${lg} t$ diagram where $T_s$ is the surface temperature. Compared to the corresponding hadronic model which well fits existing data the model for the hybrid neutron star (with a large diquark gap) shows too fast cooling. The same conclusion can be drawn for the corresponding self-bound objects.Comment: 8 pages, 4 figures, uses aa-package (included), accepted for A&

In vitro susceptibility of contagious ovine digital dermatitis associated Treponema spp. isolates to antimicrobial agents in the UK

Background: Contagious ovine digital dermatitis (CODD) is an important cause of infectious lameness in sheep in the UK and Ireland and has a severe impact on the welfare of affected individuals. The three treponemal phylogroups Treponema medium/Treponema vincentii-like, Treponema phagedenis-like and Treponema pedis spirochaetes have been associated with clinical CODD lesions and are considered to be a necessary cause of disease. There are scant data on the antimicrobial susceptibility of the treponemes cultured from CODD lesions. Objective: The aim of this study was to determine in vitro the miniumum inhibitory concentration/ minimum bactericidal concentration (MIC/MBC) of antimicrobials used in the sheep industry for isolates of the three CODD associated treponeme phylogroups T. medium/T. vincentii-like, T. phagedenis-like and T. pedis. Animals: Twenty treponeme isolates; from 19 sheep with clinical CODD lesions. Methods: A microdilution method was used to determine in vitro the MIC/MBC of 10 antimicrobial agents for 20 treponeme isolates (five T. medium/T. vincentii-like, 10 T. phagedenis-like and five T. pedis). The antimicrobials tested were penicillin G, amoxicillin, oxytetracycline, tilmicosin, lincomycin, spectinomycin, tylosin, tildipirosin, tulathromycin and gamithromycin. Results: The treponeme isolates tested showed low MICs and MBCs to all 10 antimicrobials tested. They were most susceptible to gamithromycin and tildipirosin (MIC90: 0.0469 mg/L), and were least susceptible to lincomycin, spectinomycin and oxytetracycline (MIC90: 48 mg/L, 24 mg/L and 3 mg/L, respectively). Conclusions: These data are comparable to in vitro antimicrobial susceptibility data for treponemes cultured from bovine digital dermatitis lesions. Dependent on local licensing, penicillin and tilmicosin appear to be the best candidates for future in vivo studies. © 2015 ESVD & ACVD

Severe foot lesions in dairy goats associated with digital dermatitis treponemes

Treponeme-associated foot disease has been described in cattle with digital dermatitis and sheep with contagious ovine digital dermatitis. In this study, severe foot lesions in dairy goats associated with digital dermatitis treponemes (i.e. Treponema medium, Treponema phagedenis and Treponema pedis) were characterized macroscopically, radiographically and histologically. The main macroscopic foot lesion was of extensive solar ulceration with or without exophytic papilliform hyperkeratosis. Radiographically, the distal phalanx and distal sesamoid bones were severely damaged and remodelled. Histologically, the lesion was categorized as a chronic lymphoplasmacytic, suppurative and ulcerative pododermatitis. Immunohistochemistry identified the spirochaetal microorganisms located extracellularly in the superficial horn. Study limitations mean that the treponeme bacteria could not be considered the sole or causal agents in the cases described. © 2016 The Authors

Patterns of social determinants of health associated with drug use among women living with HIV in Canada: a latent class analysis

Background and AimsIdentifying typologies of social determinants of health (SDoH) vulnerability influencing drug use practices among women living with HIV (WLWH) can help to address associated harms. This research aimed to explore the association of SDoH clusters with drug use among WLWH.DesignLatent class analysis (LCA) was used to identify the distinct clusters of SDoH. Inverse probability weighting (IPW) was employed to account for confounding and potential selection bias. Associations were analyzed using generalized linear model with log link and Poisson distribution, and then weighted risk ratio (RR) and 95% confidence intervals (CI) were reported.Setting and ParticipantsData from 1422 WLWH recruited at timeâ point 1 of the Canadian HIV Women’s Sexual and Reproductive Health Cohort Study (CHIWOS, 2013â 15), with 1252 participants at 18 months followâ up (timeâ point 2).MeasurementsDrug use was defined as use of illicit/nonâ prescribed opioids/stimulants in the past 6 months. SDoH indicators included: race discrimination, gender discrimination, HIV stigma, social support, access to care, food security, income level, employment status, education, housing status and histories of recent sex work and incarceration.FindingsLCA identified four SDoH classes: no/least SDoH adversities (6.6%), discrimination/stigma (17.7%), economic hardship (30.8%) and most SDoH adversities (45.0%). Drug use was reported by 17.5% and 17.2% at timeâ points 1 and 2, respectively. WLWH with no/least SDoH adversities were less likely to report drug use than those in economic hardship class (weighted RR = 0.13; 95% CIs = 0.03, 0.63), discrimination/stigma class (weighted RR = 0.15; 95% CIs = 0.03, 0.78), and most SDoH adversities class (weighted RR = 0.13; 95% CIs = 0.03, 0.58).ConclusionsSocial determinants of health vulnerabilities are associated with greater likelihood of drug use, underscoring the significance of addressing interlinked social determinants and drug use through the course of HIV care and treatment.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149504/1/add14566_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149504/2/add14566.pd

Multistate modeling of habitat dynamics: factors affecting Florida scrub transition probabilities

Many ecosystems are influenced by disturbances that create specific successional states and habitat structures that species need to persist. Estimating transition probabilities between habitat states and modeling the factors that influence such transitions have many applications for investigating and managing disturbance-prone ecosystems. We identify the correspondence between multistate capture-recapture models and Markov models of habitat dynamics. We exploit this correspondence by fitting and comparing competing models of different ecological covariates affecting habitat transition probabilities in Florida scrub and flatwoods, a habitat important to many unique plants and animals. We subdivided a large scrub and flatwoods ecosystem along central Florida\u27s Atlantic coast into 10-ha grid cells, which approximated average territory size of the threatened Florida Scrub-Jay (Aphelocoma coerulescens), a management indicator species. We used 1.0-m resolution aerial imagery for 1994, 1999, and 2004 to classify grid cells into four habitat quality states that were directly related to Florida Scrub-Jay source-sink dynamics and management decision making. Results showed that static site features related to fire propagation (vegetation type, edges) and temporally varying disturbances (fires, mechanical cutting) best explained transition probabilities. Results indicated that much of the scrub and flatwoods ecosystem was resistant to moving from a degraded state to a desired state without mechanical cutting, an expensive restoration tool. We used habitat models parameterized with the estimated transition probabilities to investigate the consequences of alternative management scenarios on future habitat dynamics. We recommend this multistate modeling approach as being broadly applicable for studying ecosystem, land cover, or habitat dynamics. The approach provides maximum-likelihood estimates of transition parameters, including precision measures, and can be used to assess evidence among competing ecological models that describe system dynamics

Physics of Neutron Star Crusts

The physics of neutron star crusts is vast, involving many different research fields, from nuclear and condensed matter physics to general relativity. This review summarizes the progress, which has been achieved over the last few years, in modeling neutron star crusts, both at the microscopic and macroscopic levels. The confrontation of these theoretical models with observations is also briefly discussed.Comment: 182 pages, published version available at <http://www.livingreviews.org/lrr-2008-10

A molecular epidemiology of treponemes in beef cattle digital dermatitis lesions and comparative analyses with sheep contagious ovine digital dermatitis and dairy cattle digital dermatitis lesions

Bovine digital dermatitis (BDD) is an infective foot disease commonly reported in dairy cattle where Treponema are considered as the primary causative infectious agents. There still remains little definitive information on the etiology of BDD in beef cattle suggesting further investigations are warranted. Beef BDD lesions (. n=. 34) and healthy beef foot tissues (. n=. 38) were analysed by PCR for three BDD-associated Treponema phylogroups and also for Dichelobacter nodosus and Fusobacterium necrophorum. Spirochete culture was attempted on all BDD lesion samples. One or more BDD-associated Treponema phylogroups were detected in 100 of beef BDD lesions. ". Treponema medium/Treponema vincentii-like", ". Treponema phagedenis-like" and Treponema pedis spirochetes were identified in 27/34 (79), 31/34 (91) and 24/34 (71) of BDD lesions, respectively. No BDD-associated treponeme DNA was amplified from beef healthy foot tissues. D. nodosus and F. necrophorum were present in 24/34 (71) and 15/34 (44) of lesions and 10/38 (26) and 12/38 (32) of healthy foot tissues, respectively. Twenty spirochetes were isolated from beef BDD lesions; 19 were representatives of the three BDD-associated Treponema phylogroups. One spirochete isolate shared less than 97 16S rRNA gene similarity to the three cultivable BDD-associated Treponema phylogroups and therefore may represent a novel taxa of Treponema. Upon comparison, sheep contagious ovine digital dermatitis (CODD), dairy cattle and beef cattle BDD lesions appear to have extremely similar bacteriological data and therefore provides evidence of a shared etiopathogenesis posing concerns for cross-species transmission. © 2015 Elsevier B.V