Strong Coupling of Epsilon-Near-Zero Phonon Polaritons in Polar Dielectric Heterostructures

We report the first observation of epsilon near zero (ENZ) phonon polaritons in an ultrathin AlN film fully hybridized with surface phonon polaritons (SPhP) supported by the adjacent SiC substrate. Employing a strong coupling model for the analysis of the dispersion and electric field distribution in these hybridized modes, we show that they share the most prominent features of the two precursor modes. The novel ENZ-SPhP coupled polaritons with a highly propagative character and deeply sub-wavelength light confinement can be utilized as building blocks for future infrared and terahertz (THz) nanophotonic integration and communication devices

Transmission of bovine viral diarrhea virus among white-tailed deer (Odocoileus virginianus)

Cattle persistently infected (PI) with bovine viral diarrhea virus (BVDV), a pestivirus in the family Flaviviridae, are an important source of viral transmission to susceptible hosts. Persistent BVDV infections have been identified in white-tailed deer (Odocoileus virginianus), the most abundant free-ranging ruminant in North America. As PI deer shed BVDV similarly to PI cattle, maintenance of BVDV within white-tailed deer populations may be possible. To date, intraspecific transmission of BVDV in white-tailed deer has not been evaluated, which prompted this study. Six pregnant white-tailed deer were captured in the first trimester of pregnancy and cohabitated with a PI white-tailed deer. Cohabitation with the PI deer resulted in BVDV infection in all does, as indicated by seroconversion. All does gave birth to live fawns and no reproductive losses were observed. At birth, evidence of BVDV infection was identified in two singlet fawns, of which one was determined to be PI by repeated serum reverse transcription nested PCR, whole blood virus isolation and immunohistochemistry. This study demonstrates for the first time that BVDV transmission may occur among white-tailed deer. The birth of a PI fawn through contact to a PI white-tailed deer indicates that under appropriate circumstances, BVDV may be maintained in white-tailed deer by congenital infection

Corrections

Surface phonon polaritons (SPhP) and surface plasmon polaritons (SPP), evanescent modes supported by media with negative permittivity, are a fundamental building block of nanophotonics. These modes are unmatched in terms of field enhancement and spatial confinement, and dynamical all-optical control can be achieved e.g. by employing phase-change materials (PCMs). However, the excitation of surface polaritons in planar structures is intrinsically limited to p-polarization. On the contrary, waveguide modes in high-permittivity films can couple to both p- and s-polarized light, and in thin films, their confinement can become comparable to surface polaritons. Here we demonstrate that the s-polarized waveguide mode in a thin Ge3Sb2Te6 (GST) film features a similar dispersion, confinement, and electric field enhancement as the SPhP mode of the silicon carbide (SiC) substrate, while even expanding the allowed frequency range. Moreover, we experimentally show that switching the GST film grants non-volatile control over the SPhP and the waveguide mode dispersions. We provide an analytical model for the description of the GST/SiC waveguide mode and show that our concept is applicable to the broad variety of polar crystals throughout the infrared spectral range. As such, complementarily to the polarization-limited surface polaritons, the s-polarized PCM waveguide mode constitutes a promising additional building block for nanophotonic applications

Control of Pestivirus Infections in the Management of Wildlife Populations

Infections with recognized and putative species of the genus pestivirus are not host-specific and are documented in many wildlife species. The study of pestivirus infections in wildlife species is important both to eradication programs and programs for maintaining the health and well-being of wildlife populations. Free-ranging wildlife species may act as reservoirs for pestiviruses that infect domestic species. For this reason, eradication efforts for classical swine fever virus include control of the virus in wild boar populations. The contribution of free-ranging species to the circulation of BVDV1, BVDV2, and BDV is less well understood. While substantial damage due to pestivirus infections has been demonstrated in a few specific wildlife populations, the impact of pestiviral infections on the well-being of most captive and free-ranging wildlife populations is largely unknown. The research topics summarizes our current understanding of pestiviral infections in wildlife and discusses the challenges in understanding and mediating their impact on captive and free ranging wildlife species

Seroprevalence and risk factors associated with Corynebacterium pseudotuberculosis detectable antibodies in equids in Alabama

A cross-sectional serological survey was carried out to screen the equine population of the nonendemic state of Alabama for the presence of detectable antibody titers against Corynebacterium pseudotuberculosis. A second objective was to determine the association of detectable titers with risk factors such as exposure to ruminants or previous travel to endemic states. A total of 342 equine serum samples from 40 Alabama counties were analyzed using the synergistic hemolysis inhibition test (SHI). The prevalence of detectable antibody titers (≥1:8) was 52.5% (95% confidence interval [CI], 47%–57.9%). Titers ≥1:128 were detected in 2.63% (95% CI, 1.2%–4.9%), and titers ≥1:512 were detected in 0.3% (95%\ua0CI, 0%–1.6%) of the sampled population. In the final generalized linear model, age (P\ua

Changes introduced in the open reading frame of bovine viral diarrhea virus during serial infection of pregnant swine

Bovine viral diarrhea virus (BVDV) is one of the most economically important viruses of cattle, but this pathogen is also able to infect pigs, camelids, and a wide range of domestic and wild ruminants. BVDV isolates circulating in animal populations are genetically and antigenically highly diverse. Acute BVDV infections in cattle cause the introduction of many substitutions in the viral genome. Serial infection of pregnant sheep with a BVDV-1b isolate of bovine origin was also associated with great numbers of substitutions. To our knowledge, genomic changes arising during BVDV infections in swine have not been investigated. The purpose of this study was to investigate the changes occurring in the open reading frame (ORF) of BVDV during serial infection of pregnant swine with a BVDV isolate of bovine origin. The BVDV-1b isolate AU526 was serially passaged in six pregnant gilts, two of which gave birth to live piglets congenitally infected with BVDV. The complete ORF sequences of 14 BVDV isolates obtained from pregnant gilts and their piglets were determined. Their analysis revealed that serial transmission of AU526 in pregnant swine resulted in many genomic changes. All isolates of porcine origin shared 32 nucleotide and 12 amino acid differences with the virus inoculum AU526. These changes were detected after a single passage in pregnant swine and were conserved during the subsequent five passages. Amino acid changes occurred primarily in genomic regions encoding the BVDV structural proteins E2 and E rns . These results suggest that BVDV infections in pregnant swine may contribute significantly to the genetic variability of BVDV and lead to the appearance of adaptive changes

Comparison of atlantoaxial and lumbosacral cerebrospinal fluid centesis techniques in South American camelids

Abstract Background Iatrogenic blood contamination during cerebrospinal fluid (CSF) centesis is common, which can limit the diagnostic usefulness of the sample. A novel ultrasound‐guided CSF collection technique is described in horses, by which CSF is obtained from the atlantoaxial (AA) space. Hypothesis/Objectives To compare ultrasound‐guided AA centesis with lumbosacral (LS) centesis in South American camelids (SAC). The hypotheses were that AA centesis would yield samples with less blood contamination although being technically more challenging than LS centesis. Animals Eight clinically healthy adult SAC from a university‐owned teaching herd. Methods Single‐blinded, randomized, 4‐way, 4‐period crossover study in which 2 veterinarians each performed both centesis techniques on each animal once. Cytological sample analysis was performed, and the technical difficulty of sample acquisition was assessed. Results The CSF was collected successfully and without complications by either technique during all collection attempts. Aspects of technical difficulty and concentrations of CSF analytes did not vary significantly between techniques. Median total nucleated cell and red blood cell counts were 1/μL and 0.5/μL and 167.5/μL and 155/μL for AA and LS techniques, respectively. The median total protein concentration was 32.9 mg/dL and 38 mg/dL for AA and LS centeses. A median of 1 attempt was necessary for both centesis techniques and the median number of needle repositioning events was 1 for AA and 0 for LS. Conclusion and Clinical Importance Depending on clinical circumstances, ultrasound‐guided AA centesis appears to be an acceptable alternative to other techniques for collection of CSF from SAC