6,396 research outputs found

    Time Variations in Elemental Abundances in Solar Energetic Particle Events

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    The Solar Isotope Spectrometer (SIS) on-board the Advanced Composition Explorer has a large collection power and high telemetry rate, making it possible to study elemental abundances in large solar energetic particle (SEP) events as a function of time. Results have now been obtained for more than 25 such events. Understanding the causes of these variations is key to obtaining reliable solar elemental abundances and to understanding solar acceleration processes. Such variations have been previously attributed to two models: (1) a mixture of an initial impulsive phase having enhanced heavy element abundances with a longer gradual phase with coronal abundances and (2) rigidity dependent escape from CME-driven shocks through plasma waves generated by wave-particle interactions. In this second model the injected abundances are assumed to be coronal. Both these models can be expected to depend upon solar longitude since impulsive events are associated with flares at longitudes well-connected magnetically to the observer, and shock properties and connection of the observer to the shock are also longitude dependent. We present results on temporal variations from event to event and within events and show that they appear to have a longitude dependence. We show that the events which have been well-explained by model (2) tend to be near central meridian or the west limb. In addition, we show that there are events with little time variation and heavy element enhancements similar to those of impulsive events. These events seem to be better explained by model (1) with only an impulsive phase

    Validation of monoclonal antibody F99/97.6.1 for immunohistochemical staining of brain and tonsil in mule deer (\u3ci\u3eOdocoileus hemionus\u3c/i\u3e) with chronic wasting disease

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    A new monoclonal antibody (MAb), F99/97.6.1, that has been used to demonstrate scrapieassociated prion protein PrPSc in brain and lymphoid tissues of domestic sheep with scrapie was used in an immunohistochemistry assay for diagnosis of chronic wasting disease (CWD) in mule deer (Odocoileus hemionus). The MAb F99/97.6.1 immunohistochemistry assay was evaluated in brain and tonsil tissue from 100 mule deer that had spongiform encephalopathy compatible with CWD and from 1,050 mule deer outside the CWD-endemic area. This MAb demonstrated abnormal protease-resistant prion protein (PrPres) in brains of all of the 100 mule deer and in 99 of the 100 tonsil samples. No immunostaining was seen in samples collected from deer outside the endemic area. MAb F99/97.6.1 demonstrated excellent properties for detection of PrPres in fresh, frozen, or mildly to moderately autolytic samples of brain and tonsil. This immunohistochemistry assay is a sensitive, specific, readily standardized diagnostic test for CWD in deer

    Validation of monoclonal antibody F99/97.6.1 for immunohistochemical staining of brain and tonsil in mule deer (\u3ci\u3eOdocoileus hemionus\u3c/i\u3e) with chronic wasting disease

    Get PDF
    A new monoclonal antibody (MAb), F99/97.6.1, that has been used to demonstrate scrapieassociated prion protein PrPSc in brain and lymphoid tissues of domestic sheep with scrapie was used in an immunohistochemistry assay for diagnosis of chronic wasting disease (CWD) in mule deer (Odocoileus hemionus). The MAb F99/97.6.1 immunohistochemistry assay was evaluated in brain and tonsil tissue from 100 mule deer that had spongiform encephalopathy compatible with CWD and from 1,050 mule deer outside the CWD-endemic area. This MAb demonstrated abnormal protease-resistant prion protein (PrPres) in brains of all of the 100 mule deer and in 99 of the 100 tonsil samples. No immunostaining was seen in samples collected from deer outside the endemic area. MAb F99/97.6.1 demonstrated excellent properties for detection of PrPres in fresh, frozen, or mildly to moderately autolytic samples of brain and tonsil. This immunohistochemistry assay is a sensitive, specific, readily standardized diagnostic test for CWD in deer

    Modelling colloids with Baxter's adhesive hard sphere model

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    The structure of the Baxter adhesive hard sphere fluid is examined using computer simulation. The radial distribution function (which exhibits unusual discontinuities due to the particle adhesion) and static structure factor are calculated with high accuracy over a range of conditions and compared with the predictions of Percus--Yevick theory. We comment on rigidity in percolating clusters and discuss the role of the model in the context of experiments on colloidal systems with short-range attractive forces.Comment: 14 pages, 7 figures. (For proceedings of "Structural arrest in colloidal systems with short-range attractive forces", Messina, December 2003

    The impact of the demographic transition on dengue in Thailand: Insights from a statistical analysis and mathematical modeling

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    Background: An increase in the average age of dengue hemorrhagic fever (DHF) cases has been reported in Thailand. The cause of this increase is not known. Possible explanations include a reduction in transmission due to declining mosquito populations, declining contact between human and mosquito, and changes in reporting. We propose that a demographic shift toward lower birth and death rates has reduced dengue transmission and lengthened the interval between large epidemics. Methods and Findings: Using data from each of the 72 provinces of Thailand, we looked for associations between force of infection (a measure of hazard, defined as the rate per capita at which susceptible individuals become infected) and demographic and climactic variables. We estimated the force of infection from the age distribution of cases from 1985 to 2005. We find that the force of infection has declined by 2% each year since a peak in the late 1970s and early 1980s. Contrary to recent findings suggesting that the incidence of DHF has increased in Thailand, we find a small but statistically significant decline in DHF incidence since 1985 in a majority of provinces. The strongest predictor of the change in force of infection and the mean force of infection is the median age of the population. Using mathematical simulations of dengue transmission we show that a reduced birth rate and a shift in the population's age structure can explain the shift in the age distribution of cases, reduction of the force of infection, and increase in the periodicity of multiannual oscillations of DHF incidence in the absence of other changes. Conclusions: Lower birth and death rates decrease the flow of susceptible individuals into the population and increase the longevity of immune individuals. The increase in the proportion of the population that is immune increases the likelihood that an infectious mosquito will feed on an immune individual, reducing the force of infection. Though the force of infection has decreased by half, we find that the critical vaccination fraction has not changed significantly, declining from an average of 85% to 80%. Clinical guidelines should consider the impact of continued increases in the age of dengue cases in Thailand. Countries in the region lagging behind Thailand in the demographic transition may experience the same increase as their population ages. The impact of demographic changes on the force of infection has been hypothesized for other diseases, but, to our knowledge, this is the first observation of this phenomenon

    The Pivotal Role of the Pharmacist in a Primary Care Office

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    Abstract The profession of pharmacy has evolved from a dispensing role to an interdisciplinary clinical role in patient care. One area of patient care expertise is Medication Therapy Management (MTM), which includes services such as pharmacotherapy, medication therapy reviews, disease management, immunizations and other clinical services. In various studies, pharmacists conducting MTM have shown improved patient outcomes in community pharmacy and hospital settings. Amidst the valuable services all healthcare professionals are providing, increasing medical costs and consequences have become overwhelming, leading to negative patient outcomes. A lack of primary care physicians (PCPs) may contribute to these distressing facts. Gaps in communication between hospital, PCPs and community pharmacies also contribute to negative patient outcomes. Pharmacists can bridge the gap in miscommunication and help improve patient outcomes. Thus far in practice, pharmacists have had a limited role in primary care settings. The objective of this study is to determine if the addition of pharmacists providing clinical services (i.e. MTM) in a primary care setting can support the prescribers’ patient care demands. For this observational, exploratory research, the primary care settings under study will be all Federally Qualified Health Centers (FQHCs) in Ohio. IRB approval will be acquired before contact is made with participants. The contact person from each FQHC has been identified from the HRSA Office of Pharmacy Affairs. A script will be used to gather email addresses for the manager, physician, nurse and pharmacist, if available, from the contact person. A Qualtrics survey will be administered to these participants via email. The purpose of this study is to establish components of patient care in a primary care office, specifically FQHCs, that other medical professionals identify as lacking, which pharmacists can provide. A consent form, information about the study and a link to the survey will be provided in an email. The survey will include demographic, open-ended and 5-point Likert-type scale (1=strongly agree, 5=strongly disagree) questions. Reliability and validity of the survey will be established by a thorough search of the literature and expert review. Submitted answers will be analyzed with the appropriate statistical tests

    A field study of team working in a new human supervisory control system

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    This paper presents a case study of an investigation into team behaviour in an energy distribution company. The main aim was to investigate the impact of major changes in the company on system performance, comprising human and technical elements. A socio-technical systems approach was adopted. There were main differences between the teams investigated in the study: the time of year each control room was studied (i.e. summer or winter),the stage of development each team was in (i.e. 10 months), and the team structure (i.e. hierarchical or heterarchical). In all other respects the control rooms were the same: employing the same technology and within the same organization. The main findings were: the teams studied in the winter months were engaged in more `planning’ and `awareness’ type of activities than those studies in the summer months. Newer teams seem to be engaged in more sharing of information than older teams, which maybe indicative of the development process. One of the hierarchical teams was engaged in more `system-driven’ activities than the heterarchical team studied at the same time of year. Finally, in general, the heterarchical team perceived a greater degree of team working culture than its hierarchical counterparts. This applied research project confirms findings from laboratory research and emphasizes the importance of involving ergonomics in the design of team working in human supervisory control

    Fourth Ventricular Schwannoma: Identical Clinicopathologic Features as Schwann Cell-Derived Schwannoma with Unique Etiopathologic Origins

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    Background. To our knowledge, this is the sixth reported case in the literature of fourth ventricular schwannoma. The etiology and natural history of intraventricular schwannomas is not well understood. A thorough review of potential etiopathogenic mechanisms is provided in this case report. Case Description. A 69-year-old man presented with an incidentally found fourth ventricular tumor during an evaluation for generalized weakness, gait instability, and memory disturbance. Magnetic resonance imaging (MRI) revealed a heterogeneously enhancing lesion in the fourth ventricle. A suboccipital craniotomy was performed to resect the lesion. Histopathological examination confirmed the diagnosis of schwannoma (WHO grade I). Conclusions. Schwannomas should be considered in the differential diagnosis of intraventricular tumors. Although the embryologic origins may be different from nerve sheath-derived schwannomas, the histologic, clinical, and natural history appear identical and thus should be managed similarly
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