Transmission of Porcine Reproductive and Respiratory Syndrome Virus by Semen is Dose Dependent

Procine reproductive and respiratory syndrome virus (PRRSV) is transmitted through semen via natural mating or atrificial insemination. However, the minimal infective dose of PRRSV required to effect transmission through semen is not known. In this study, we induced estrus in PRRSV seronegative gilts and then artificially inseminated these animals with extended, commercial boar semen “seeded” with difference concentrations (2, 20, 200, 2,000, 20,000, 200,000, or 2,000,000 TCID50/50 ml of semen) of the PRRSV isolate SD 92-23983. Infection of gilts by PRRSV was confirmed by weekly bleedings of these animals to detect serconversion using the commercial IDEXX ELISA. All pigs (n=7) given ≥ 200,000 doses of PRRSV seroconverted 1 to 3 weeks after insemination. In contrast, only 1/5 and 1/5 pigs serconverted at dosages of 20,000 and 2,000, respectively. There was no seroconversion (0/14 pigs) at dosages ≤ 200. Pigs, wich did not seroconvert 4 to 5 weeks after artificial insemination with semen containing 200, 2,000, and 20,000 infectious doses of PRRSV, were intranasally inoculated with the same amount of virus. After intransal challenge 4/4 (20,000 doses), 4/4 (2,000 doses) and 0/4 (200 doses) pigs seroconverted within 1 to 3 weeks after inculation. The results indicated that higher infectious does of PRRSV/ml are required for transmission via semen compared to intransal inoculation, and the nested PCR assay can detect viral RNA in semen at concentrations that do not result in transmission of PRRSV by artificial insemenation

Evaluation of a Macrophage Attenuated Isolate of PRRSV as a Vaccine for Porcine Reproductive and Respiratory Syndrome Virus

PRRS continues to be the most economically important disease of swine. While the acute reproductive disease is still prevalent, chronic, or endemic PRRS in nursery and grow/finish pigs is a major problem confronting most swine producers. Post-weaning problems in these herds include a 50-85% reduction in growth rates; a 10-30% increase in unmarketable pigs; and a 10-25% increase in psot-weaning morality. Popular protocols to manage PRRSV infections include bredding herd stabilization; elmination of seronegative sub-populations of susceptible gilts; nursery depopulation; and more recently mass vaccination/unidirectional pig flow in the grow/finsih unit. The goal of this project is to determine if an isolate of PRRSV, that has been moditifed by serial passage in monkey kidney cells (MARC-145) and replicates at very low levels in procine alveolar macrophages, is avirulent for pigs an pregnant gilts

Demonstrating frequency-dependent transmission of sarcoptic mange in red foxes

Understanding the relationship between disease transmission and host density is essential for predicting disease spread and control. Using long-term data on sarcoptic mange in a red fox Vulpes vulpes population, we tested long-held assumptions of density- and frequency-dependent direct disease transmission. We also assessed the role of indirect transmission. Contrary to assumptions typical of epidemiological models, mange dynamics are better explained by frequency-dependent disease transmission than by density-dependent transmission in this canid. We found no support for indirect transmission. We present the first estimates of R0 and age-specific transmission coefficients for mange in foxes. These parameters are important for managing this poorly understood but highly contagious and economically damaging disease

Reevaluating the role of verbalisation of faces for composite production: Descriptions of offenders matter!

Standard forensic practice necessitates that a witness describes an offender’s face prior to constructing a visual likeness, a facial composite. However, describing a face can interfere with face recognition, although a delay between description and recognition theoretically should alleviate this issue. In Experiment 1, participants produced a free recall description either 3-4 hours or 2 days after intentionally or incidentally encoding a target face, and then constructed a composite using a modern ‘feature’ system immediately or after 30-minutes. Unexpectedly, correct naming of composites significantly reduced following the 30-minute delay between description and construction for targets encoded 2 days previously. In, Experiment 2, participants in these conditions gave descriptions that were better matched to their targets by independent judges, a result which suggests that the 30-minute delay actually impairs access to details of recalled descriptions that are valuable for composite effectiveness. Experiment 3 found the detrimental effect of description delay extended to composites constructed from a ‘holistic’ face production system. The results have real-world but counterintuitive implications for witnesses who construct a face one or two days after a crime: after having recalled the face to a practitioner, an appreciable delay (here, 30 minutes) should be avoided before starting face construction

Pengembangan Model Persamaan Matematika Presipitasi CaCO3 pada Sistem Sirkulasi Fluida Dinamik

Air sadah banyak mengandung ion Ca2+ dan ion CO3 2- yang dapat berpresipitasi membentuk CaCO3. Magnetisasi air sadah dapat mengurangi kandungan ion Ca2+ dan ion CO3 2- dengan mempercepat proses presipitasinya. Kecepatan alir, kuat medan, dan ,konsentrasi awal Ca2+ merupakan variabel proses yang berpengaruh terhadap presipitasi CaCO3 pada magnetisasi air sadah sistem sirkulasi fluida dinamik. Tujuan penelitian ini adalah mendapatkan suatu model persaman matematik yang dapat menghitung jumlah presipitasi CaCO3 yang terjadi pada proses magnetisasi air sadah sebagai fungsi variabel proses. Data kinetik percobaan presipitasi CaCO3 yang sudah dilakukan pada penelitian sebelumnya menjadi dasar dan pembanding dalam pengembangan model tersebut. Model persamaan matematika yang didapat berhasil mensimulasi dengan baik pengaruh variabel proses terhadap presipitasi CaCO3 dimana data hasil perhitungan mendekati data hasil percobaan

The 1:1 resonance in Extrasolar Systems: Migration from planetary to satellite orbits

We present families of symmetric and asymmetric periodic orbits at the 1/1 resonance, for a planetary system consisting of a star and two small bodies, in comparison to the star, moving in the same plane under their mutual gravitational attraction. The stable 1/1 resonant periodic orbits belong to a family which has a planetary branch, with the two planets moving in nearly Keplerian orbits with non zero eccentricities and a satellite branch, where the gravitational interaction between the two planets dominates the attraction from the star and the two planets form a close binary which revolves around the star. The stability regions around periodic orbits along the family are studied. Next, we study the dynamical evolution in time of a planetary system with two planets which is initially trapped in a stable 1/1 resonant periodic motion, when a drag force is included in the system. We prove that if we start with a 1/1 resonant planetary system with large eccentricities, the system migrates, due to the drag force, {\it along the family of periodic orbits} and is finally trapped in a satellite orbit. This, in principle, provides a mechanism for the generation of a satellite system: we start with a planetary system and the final stage is a system where the two small bodies form a close binary whose center of mass revolves around the star.Comment: to appear in Cel.Mech.Dyn.Ast

Vortex Lattice Melting into Disentangled Liquid Followed by the 3D-2D Decoupling Transition in YBa_2Cu_4O_8 Single Crystals

A sharp resistance drop associated with vortex lattice melting was observed in high quality YBa_2Cu_4O_8 single crystals. The melting line is well described well by the anisotropic GL theory. Two thermally activated flux flow regions, which were separated by a crossover line B_cr=1406.5(1-T/T_c)/T (T_c=79.0 K, B_cr in T), were observed in the vortex liquid phase. Activation energy for each region was obtained and the corresponding dissipation mechanism was discussed. Our results suggest that the vortex lattice in YBa_2Cu_4O_8 single crystal melts into disentangled liquid, which then undergoes a 3D-2D decoupling transition.Comment: 5 pages, 4 eps figures, RevTex (Latex2.09

Association Between Superwoman Schema, Depression, and Resilience: The Mediating Role of Social Isolation and Gendered Racial Centrality

Objectives: We examined dimensions of Superwoman Schema as predictors of both depression and resilience. We also investigated if social isolation and gendered racial centrality mediated these relationships. Method: We used path analysis to investigate the direct and indirect effects of an obligation to display an image of strength, emotional suppression, and resistance to vulnerability on depressive symptoms through social isolation. We also explored the direct and indirect effects of an intense motivation to succeed and an obligation to help others on resilience through gendered racial centrality. Results: Emotional suppression and an obligation to help others were directly associated with depression. Emotional suppression, resistance to vulnerability, and an obligation to help others were indirectly associated with depression through social isolation. In contrast, an obligation to display an image of strength and an intense motivation to succeed was associated with resilience and gendered racial centrality. Conclusion: Findings highlight the unique complexity of Superwoman Schema as suggested within qualitative research. Black women’s endorsement of Superwoman Schema may be both adaptive in navigating interlocking systems of oppression and psychologically distressin

Flavor Alignment Solutions to the Strong CP Problem in Supersymmetry

An approach to solving the Strong CP Problem in supersymmetric theories is discussed which uses abelian family symmetries to align the mass matrices of the quarks and squarks. In this way both the Strong CP Problem and the characteristic flavor and CP problems of supersymmetry can be solved in a single way.Comment: 13 pages, LaTe

QCD Corrections to K-Kbar Mixing in R-symmetric Supersymmetric Models

The leading-log QCD corrections to K-Kbar mixing in R-symmetric supersymmetric models are computed using effective field theory techniques. The spectrum topology where the gluino is significantly heavier than the squarks is motivated and focused on. It is found that, like in the MSSM, QCD corrections can tighten the kaon mass difference bound by roughly a factor of three. CP violation is also briefly considered, where QCD corrections can constrain phases to be as much as a factor of ten smaller than the uncorrected value.Comment: 11 pages, 11 pdf-figures; updated acknowledgments and references, clarified relationship to Ref[17], clarified CP-violation sectio