1,114 research outputs found

    On the Pressure Broadening in the Gamma Bands of Nitric Oxide

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    A quantitative investigation of the pressure broadening in the γ(0,0) and γ(1,0) bands of nitric acid established that the pressure effect is not abnormal as has sometimes been supposed and that the collision diameter of the excited NO molecule is approximately 3.8 Å

    Leg Power as Affected by Selected Weight Training Exercises and Forced-Stretch Training

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    Many athletes score well on strength tests but cannot throw or jump proportional distances. In other words, they are unable to produce the power necessary for explosive-type events. There appears to be a gap in training techniques concerning the relationship between strength and power. Zanon has attempted to bridge this gap through his description of exercises which utilize the concept that muscles contract with greater force if this contraction in preceded by forced-stretching of leg with hip extensor muscles. At present, research relative to use of forced-stretch training exercises are used for long jumpers ad triple jumpers, underlying principles are not well understood. Further progress in improvement of present world jumping and throwing records will require improvement in methods of training presently employed. In this study the present investigator attempted to determine whether the forced-stretch concept of training might be used to improve jumping capabilities of athletes in sports requiring explosive action. The purpose of this study was to conduct a comparative analysis of the effects of selected exercise programs involved forced-stretch training and weight training in the development of leg power among college men, as measured by performance in the thirty-yard sprint, vertical power jump, and relative force tests. Also analyzed were data obtained through relative force grouping within the experimental and control groups

    Linkage among melanin biosynthetic mutations in Cochliobolus heterostrophus

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    Melanin is synthesized by C. heterostrophus from acetate via pentaketide and several dihydroxynaphthalene intermediates (Tanaka et al. 1991 Mycol. Res. 95:49-56), as it is for certain other fungi (Bell and Wheeler 1986 Ann. Rev. Phytopathol. 24:411-451; Kubo et al. 1989 Exp. Mycol 13:77-84; Chumley and Valent 1990 Mol. Plant-Microbe Int. 3:135-143). Previously, five melanin deficient mutants of C. heterostrophus were analyzed by Tanaka et al. (Mycol. Res. 95:49-56), who were unable to establish complete linkage relationships because three of the mutations (alb1, alb3, and brn1) showed no recombination when crossed to each other, and were unlinked to the other two (sal1 and pgr1), which mapped about 12 cM apart. A sixth color mutation, scr1, represented a third linkage group, but there was no evidence of its involvement in melanin biosynthesis. Independently, we have recovered six melanin-deficient mutants, one of which (alb1, Leach et al. 1982 J. Gen. Microbiol. 128:1719-1729) was included in the study of Tanaka et al. and maps to chromosome 1 on the C. heterostrophus RFLP map (Tzeng et al. 1992 Genetics 130:81-96). We report here that our remaining five melanin-deficient mutants [crm1 (light cream), crm2 (dark cream), brn1 (brown), rsy1 (rose), and probably gra3 (gray)] are linked to, but are not allelic with, alb1 (white) and constitute a gene cluster on chromosome

    Who acquires infection from whom and how? Disentangling multi-host and multi-mode transmission dynamics in the 'elimination' era

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    Multi-host infectious agents challenge our abilities to understand, predict and manage disease dynamics. Within this, many infectious agents are also able to use, simultaneously or sequentially, multiple modes of transmission. Furthermore, the relative importance of different host species and modes can itself be dynamic, with potential for switches and shifts in host range and/ or transmission mode in response to changing selective pressures, such as those imposed by disease control interventions. The epidemiology of such multi-host, multi-mode infectious agents thereby can involve a multi-faceted community of definitive and intermediate/secondary hosts or vectors, often together with infectious stages in the environment, all of which may represent potential targets, as well as specific challenges, particularly where disease elimination is proposed. Here, we explore, focusing on examples fromboth human and animal pathogen systems, why and how we should aim to disentangle and quantify the relative importance of multi-host multi-mode infectious agent transmission dynamics under contrasting conditions, and ultimately, how this can be used to help achieve efficient and effective disease control. This article is part of the themed issue 'Opening the black box: re-examining the ecology and evolution of parasite transmission'

    Primary extranodal soft-tissue B-cell lymphoma with abundant immunoglobulin inclusions mimicking adult rhabdomyoma: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Immunoglobulin inclusions are found in B-cell neoplasms as well as in crystal-storing histiocytosis associated with B-cell lymphoproliferative disorders. At times, the deposits may be so profound as to obscure the diagnosis and may even lead to misdiagnosis. We report one case of low-grade extranodal lymphoplasmacytic lymphoma with abundant immunoglobulin inclusions and emphasize the need for immunophenotyping and molecular assay to make the right decision in diagnosis. To the best of our knowledge, this is the first report of extranodal B-cell lymphoma with abundant intracellular immunoglobulin accumulation.</p> <p>Case presentation</p> <p>A 62-year-old Asian man from China presented with a 13-year history of a right shoulder mass with recent ongoing pain. A desmoplastic fibroma located in the posterior muscles of the neck was suggested by magnetic resonance imaging, and extended local excision was performed. A biopsy, however, revealed large, isolated rhabdoid cells in a diffuse pattern with mild atypia and eosinophilic cytoplasm. Clustered lymphoid cells were interspersed among these cells. The diagnosis was initially suggested to be adult rhabdomyoma. The final diagnosis of lymphoma was made after immunohistochemical, ultrastructural and molecular studies.</p> <p>Conclusion</p> <p>We emphasize this histopathologic and immunohistochemical finding because of the potential for confusion with other tumors or disorders, such as adult rhabdomyoma or crystal-storing histiocytosis.</p

    Temporal Interferometry: A Mechanism for Controlling Qubit Transitions During Twisted Rapid Passage with Possible Application to Quantum Computing

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    In an adiabatic rapid passage experiment, the Bloch vector of a two-level system (qubit) is inverted by slowly inverting an external field to which it is coupled, and along which it is initially aligned. In twisted rapid passage, the external field is allowed to twist around its initial direction with azimuthal angle ϕ(t)\phi (t) at the same time that it is inverted. For polynomial twist: ϕ(t)Btn\phi (t) \sim Bt^{n}. We show that for n3n \geq 3, multiple avoided crossings can occur during the inversion of the external field, and that these crossings give rise to strong interference effects in the qubit transition probability. The transition probability is found to be a function of the twist strength BB, which can be used to control the time-separation of the avoided crossings, and hence the character of the interference. Constructive and destructive interference are possible. The interference effects are a consequence of the temporal phase coherence of the wavefunction. The ability to vary this coherence by varying the temporal separation of the avoided crossings renders twisted rapid passage with adjustable twist strength into a temporal interferometer through which qubit transitions can be greatly enhanced or suppressed. Possible application of this interference mechanism to construction of fast fault-tolerant quantum CNOT and NOT gates is discussed.Comment: 29 pages, 16 figures, submitted to Phys. Rev.

    Effect of home based HIV counselling and testing intervention in rural South Africa: cluster randomised trial

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    OBJECTIVE: To assess the effect of home based HIV counselling and testing on the prevalence of HIV testing and reported behavioural changes in a rural subdistrict of South Africa. DESIGN: Cluster randomised controlled trial. SETTING: 16 communities (clusters) in uMzimkhulu subdistrict, KwaZulu-Natal province, South Africa. PARTICIPANTS: 4154 people aged 14 years or more who participated in a community survey. INTERVENTION: Lay counsellors conducted door to door outreach and offered home based HIV counselling and testing to all consenting adults and adolescents aged 14-17 years with guardian consent. Control clusters received standard care, which consisted of HIV counselling and testing services at local clinics. MAIN OUTCOME MEASURES: Primary outcome measure was prevalence of testing for HIV. Other outcomes were HIV awareness, stigma, sexual behaviour, vulnerability to violence, and access to care. RESULTS: Overall, 69% of participants in the home based HIV counselling and testing arm versus 47% in the control arm were tested for HIV during the study period (prevalence ratio 1.54, 95% confidence interval 1.32 to 1.81). More couples in the intervention arm had counselling and testing together than in the control arm (2.24, 1.49 to 3.03). The intervention had broader effects beyond HIV testing, with a 55% reduction in multiple partners (0.45, 0.33 to 0.62) and a stronger effect among those who had an HIV test (0.37, 0.24 to 0.58) and a 45% reduction in casual sexual partners (0.55, 0.42 to 0.73). Conclusions Home based HIV counselling and testing increased the prevalence of HIV testing in a rural setting with high levels of stigma. Benefits also included higher uptake of couple counselling and testing and reduced sexual risk behaviour.Department of HE and Training approved lis

    Hazard Analysis of Critical Control Points Assessment as a Tool to Respond to Emerging Infectious Disease Outbreaks

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    Highly pathogenic avian influenza virus (HPAI) strain H5N1 has had direct and indirect economic impacts arising from direct mortality and control programmes in over 50 countries reporting poultry outbreaks. HPAI H5N1 is now reported as the most widespread and expensive zoonotic disease recorded and continues to pose a global health threat. The aim of this research was to assess the potential of utilising Hazard Analysis of Critical Control Points (HACCP) assessments in providing a framework for a rapid response to emerging infectious disease outbreaks. This novel approach applies a scientific process, widely used in food production systems, to assess risks related to a specific emerging health threat within a known zoonotic disease hotspot. We conducted a HACCP assessment for HPAI viruses within Vietnam’s domestic poultry trade and relate our findings to the existing literature. Our HACCP assessment identified poultry flock isolation, transportation, slaughter, preparation and consumption as critical control points for Vietnam’s domestic poultry trade. Introduction of the preventative measures highlighted through this HACCP evaluation would reduce the risks posed by HPAI viruses and pressure on the national economy. We conclude that this HACCP assessment provides compelling evidence for the future potential that HACCP analyses could play in initiating a rapid response to emerging infectious diseases

    B Cells Regulate Neutrophilia during Mycobacterium tuberculosis Infection and BCG Vaccination by Modulating the Interleukin-17 Response

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    We have previously demonstrated that B cells can shape the immune response to Mycobacterium tuberculosis, including the level of neutrophil infiltration and granulomatous inflammation at the site of infection. The present study examined the mechanisms by which B cells regulate the host neutrophilic response upon exposure to mycobacteria and how neutrophilia may influence vaccine efficacy. To address these questions, a murine aerosol infection tuberculosis (TB) model and an intradermal (ID) ear BCG immunization mouse model, involving both the μMT strain and B cell-depleted C57BL/6 mice, were used. IL (interleukin)-17 neutralization and neutrophil depletion experiments using these systems provide evidence that B cells can regulate neutrophilia by modulating the IL-17 response during M. tuberculosis infection and BCG immunization. Exuberant neutrophilia at the site of immunization in B cell-deficient mice adversely affects dendritic cell (DC) migration to the draining lymph nodes and attenuates the development of the vaccine-induced Th1 response. The results suggest that B cells are required for the development of optimal protective anti-TB immunity upon BCG vaccination by regulating the IL-17/neutrophilic response. Administration of sera derived from M. tuberculosis-infected C57BL/6 wild-type mice reverses the lung neutrophilia phenotype in tuberculous μMT mice. Together, these observations provide insight into the mechanisms by which B cells and humoral immunity modulate vaccine-induced Th1 response and regulate neutrophila during M. tuberculosis infection and BCG immunization. © 2013 Kozakiewicz et al
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