Latent

Distribution by Scientific Domains
Distribution within Medical Sciences

Terms modified by Latent

  • latent autoimmune diabetes
  • latent class
  • latent class analysis
  • latent class model
  • latent class models
  • latent construct
  • latent content analysis
  • latent demand
  • latent effects
  • latent factor
  • latent form
  • latent growth curve analysis
  • latent growth curve modeling
  • latent growth modeling
  • latent heat
  • latent heat flux
  • latent infection
  • latent inhibition
  • latent membrane
  • latent membrane protein
  • latent period
  • latent process
  • latent semantic indexing
  • latent state
  • latent structure
  • latent transforming growth factor
  • latent tuberculosis
  • latent tuberculosis infection
  • latent variable
  • latent variable approach
  • latent variable model
  • latent variable models
  • latent variable regression
  • latent virus

  • Selected Abstracts


    Latent and lytic infection of isolated guinea pig enteric ganglia by varicella zoster virus

    JOURNAL OF MEDICAL VIROLOGY, Issue S1 2003
    Jason J. Chen
    Abstract Varicella zoster virus (VZV) has been demonstrated to infect guinea pig enteric neurons in vitro. Latent infection of isolated enteric neurons is established when the cultures predominantly consist of neurons and they are exposed to cell-free VZV. Neurons harboring latent infection survive for weeks in vitro and express mRNA encoding ORFs 4, 21, 29, 40, 62, and 63, but not 14(gC) or 68 (gE) (although DNA encoding the glycoproteins is present). The expressed proteins are the same as those that are also expressed in human sensory neurons harboring latent VZV. In addition to mRNA, the immunoreactivities of ORFs 4, 21, 29, 62, and 63 can be detected. ORF 62 and 29 proteins are cytoplasmic and not intranuclear. VZV does not preferentially infect and/or become latent in intrinsic enteric primary afferent neurons indicating that the virus is latent in these neurons. Lytic infection occurs when mixed cultures of neurons and non-neuronal cells of the bowel wall are exposed to cell-free VZV or when isolated enteric neurons are exposed to cell-associated VZV. When lytic infection occurs, enteric neurons die within 48 hr. Prior to their death, neurons express VZV glycoproteins, including gE and gB, and ORF 62 and 29 proteins are intranuclear. This new animal model should facilitate studies of VZV latency and the efficacy of therapies designed to prevent VZV infecion, latency, and reactivation. J. Med. Virol. 70:S71,S78, 2003. © 2003 Wiley-Liss, Inc. [source]


    Rejoinder to "Latent Class Model Diagnosis from a Frequentist Point of View"

    BIOMETRICS, Issue 1 2003
    Scott L. Zeger
    No abstract is available for this article. [source]


    Residual cognitive impairments in remitted depressed patients,

    DEPRESSION AND ANXIETY, Issue 6 2008
    Wendelien Merens M.A.
    Abstract Depressive disorders are associated with various cognitive impairments. Studies on whether or not these impairments persist into the euthymic phase have shown conflicting results, due to differences in test versions and in study samples. In this paper, we aimed to compare the cognitive performance of remitted depressed patients with that of age- and gender-matched healthy volunteers across a wide range of cognitive domains. In two studies, we found few differences on neutral as well as emotional information processing tests. The findings indicate that remitted depressed patients who use antidepressant medication still show an increased recognition of facial expression of fear compared to healthy controls. Patients also performed worse on a test of recognition of abstract visual information from long-term memory. No other residual cognitive impairments were found. These results indicate that most of the cognitive impairments associated with depression resolve with recovery through medication, even when recovery is incomplete. Considering the finding that remitted depressed patients have higher levels of cognitive reactivity, future studies may investigate the possibility that these cognitive impairments have not resolved but have become latent, and may therefore easily be triggered by small changes in mood state. Depression and Anxiety 0:1,10, 2007. © 2007 Wiley-Liss, Inc. [source]


    Latent Separability: Grouping Goods without Weak Separability

    ECONOMETRICA, Issue 1 2000
    Richard Blundell
    This paper develops a new concept of separability with overlapping groups,latent separability. This is shown to provide a useful empirical and theoretical framework for investigating the grouping of goods and prices. It is a generalization of weak separability in which goods are allowed to enter more than one group and where the composition of groups is identified by the choice of group specific exclusive goods. Latent separability is shown to be equivalent to weak separability in latent rather than purchased goods and provides a relationship between separability and household production theory. For the popular class of linear, almost ideal and translog demand models and their generalizations, we provide a method for choosing the number of homothetic separable groups. A detailed method for exploring the composition of the separable groups is also presented. These methods are applied to a long time series of British individual household data on the consumption of twenty two nondurable and service goods. [source]


    Surveillance of vivax malaria vectors and civilian patients for malaria high-risk areas in northern Gyeonggi and Gangwon Provinces near the demilitarized zone, Republic of Korea, 2003,2006

    ENTOMOLOGICAL RESEARCH, Issue 4 2010
    Jae Chul SHIM
    Abstract After re-emergence of malaria in 1993, a continued increase in Plasmodium vivax cases was observed from 1993 to 2006 in northern Gyeonggi and Gangwon Provinces adjacent to the demilitarized zone separating North from South Korea. Annual parasite incidence per 1000 people ranged from 0.33 in 2004 to 0.89 in 2006. While malaria case rates declined (22.6%) in 2004, they increased 75.1% in 2005 and 51.7% in 2006 from the previous years. An initial incorrect diagnosis of 46.8% of malaria cases as common cold resulted in a mean delay of 1.3 days for the detection malarial parasites. Of the total cases, 10.2% from December to May were due to latent intrinsic incubation infections acquired the previous malaria season and the rest of the cases from June to November were either latent or short incubation infections. Overall, the peak anopheline population occurred from July to September, resulting in a similar peak in malaria cases. While malaria cases increased during 2005,2006, anopheline populations, based on trap indices, were not significantly different during 4 years of surveillance. To decrease the malaria patient infective period to mosquitoes, public health centers in Paju and Cheorwon in 2006 prescribed chloroquine + primaquine at days 0,3 after initial malaria diagnosis followed by an additional 11 days of primaquine (early primaquine treatment), rather than chloroquine on days 0,3 and primaquine on days 4,17 (delayed primaquine treatment). A reduction in the malaria parasite incidence during 2007 was recorded for the two locations offering the early primaquine treatment relative to other locations using the delayed primaquine treatment. [source]


    Aquatic herbicide exposure increases salamander desiccation risk eight months later in a terrestrial environment

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2005
    Jason R. Rohr
    Abstract Contaminants and climate change may be factors in amphibian declines. However, few studies have explored their joint impacts on postmetamorphic amphibians, a life stage of great importance to amphibian population dynamics. Here, we examine the effects of premetamorphic exposure (mean exposure of 64 d) to ecologically relevant concentrations of the globally common herbicide atrazine (0, 4, 40, 400 ,g/L) on the behavior and water retention of lone and grouped postmetamorphic, streamside salamanders, Ambystoma barbouri. Salamanders exposed to ,40 ,g/L of atrazine exhibited greater activity, fewer water-conserving behaviors, and accelerated water loss four and eight months after exposure compared to controls. No recovery from atrazine exposure was detected and its effects were independent of the presence of conspecifics. These results are consistent with the hypothesis that adverse climatic conditions and contaminants can interact to harm post-metamorphic amphibians; however, they suggest that these two stressors need not be experienced simultaneously to do so. These results emphasize the importance of considering both latent and cumulative effects of temporally linked stressors in ecotoxicology. [source]


    Exacerbation of experimental autoimmune encephalomyelitis in rodents infected with murine gammaherpesvirus-68

    EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 7 2003
    James
    Abstract Viral infections have long been suspected to play a role in the pathogenesis of multiple sclerosis. In the present study, two different rodent models of experimental autoimmune encephalomyelitis (EAE) were used to demonstrate the ability of murine gammaherpesvirus-68 (,HV-68) to exacerbate development of neurological symptoms. SJL mice received UV-inactivated ,HV-68 or intranasal,HV-68, followed by immunization against proteolipid-protein peptide 139,151. Infected mice became moribund within 10,days post-immunization, whereas mice exposed to UV-inactivated ,HV-68 recovered. In the second model, Lewis rats were exposed to UV-inactivated ,HV-68 or to ,HV-68, followed by passive transfer of encephalitogenic T lymphocytes specific for myelin basic protein. Consistently, infected rats had higher clinical scores, and this result was observed during acute or latent ,HV-68 infection. It is unlikely that this ,HV-68-induced exacerbation was due to significant viral replication within the central nervous system since nested PCR, viral plaque assays, and infectious-centers assays demonstrated no detectable virus in spinal cords or brains of infected rodents undergoing EAE. Taken together, these studies demonstrate increased clinical symptoms of EAE in rodents infected by a gammaherpesvirus that has a limited ability to invade the central nervous system. [source]


    Citizenship and Social Security

    FISCAL STUDIES, Issue 2 2003
    Raymond Plant
    Abstract The aim of this paper is to elucidate the idea of citizenship that lies behind the Labour government's welfare reforms. There has been no proper statement about this from the government, so the paper is an attempt to make explicit what is latent in the reforms. It does this partly historically by looking at ideas of citizenship that have been presupposed in the development of the British Welfare State. It is claimed that there are two rather different approaches to be discerned: one sees citizenship as a basic status, which in turn is the basis of entitlement; the other view is that citizenship is something that has to be developed or achieved, typically by participation in the labour market and by discharging obligations. This distinction is then used more analytically to assess some of the welfare reforms and to indicate possible sources of future difficulty and tension in so far as the government embraces the obligation-oriented view of citizenship. [source]


    A Structural Equation Approach to Models with Spatial Dependence

    GEOGRAPHICAL ANALYSIS, Issue 2 2008
    Johan H. L. Oud
    We introduce the class of structural equation models (SEMs) and corresponding estimation procedures into a spatial dependence framework. SEM allows both latent and observed variables within one and the same (causal) model. Compared with models with observed variables only, this feature makes it possible to obtain a closer correspondence between theory and empirics, to explicitly account for measurement errors, and to reduce multicollinearity. We extend the standard SEM maximum likelihood estimator to allow for spatial dependence and propose easily accessible SEM software like LISREL 8 and Mx. We present an illustration based on Anselin's Columbus, OH, crime data set. Furthermore, we combine the spatial lag model with the latent multiple-indicators,multiple-causes model and discuss estimation of this latent spatial lag model. We present an illustration based on the Anselin crime data set again. [source]


    Spatial Analysis of the Factors Contributing to the Relationship between the Transient, Meridional Eddy Sensible, and Latent Heat Flux in the Southern Hemisphere

    GEOGRAPHICAL ANALYSIS, Issue 2 2000
    Marilyn Raphael
    In this paper principal component analysis (PCA) and singular value decomposition (SVD) are used to define the importance of the variables contributing to the relationship between the transient latent and sensible heat fluxes and to show their temporal and spatial variation. SVD is offered as an alternative means of isolating spatial and temporal structures in data with the advantage that it can depict simultaneous space-time variations that are aggregates of the results produced by PCA. Both methods of analysis produced two very important uncorrelated modes of variability in January and July, indicating that the transient heat fluxes are influenced by few controlling factors. We suggest that these modes of variability represent the influences of the meridional temperature gradient, atmospheric moisture, and activity within the source and sink regions of the transient heat fluxes. The physical relationships between the heat fluxes that appear to represented by the statistical modes of variability are discussed. [source]


    Human modification of the landscape and surface climate in the next fifty years

    GLOBAL CHANGE BIOLOGY, Issue 5 2002
    R. S. Defries
    Abstract Human modification of the landscape potentially affects exchanges of energy and water between the terrestrial biosphere and the atmosphere. This study develops a possible scenario for land cover in the year 2050 based on results from the IMAGE 2 (Integrated Model to Assess the Greenhouse Effect) model, which projects land-cover changes in response to demographic and economic activity. We use the land-cover scenario as a surface boundary condition in a biophysically-based land-surface model coupled to a general circulation model for a 15-years simulation with prescribed sea surface temperature and compare with a control run using current land cover. To assess the sensitivity of climate to anthropogenic land-cover change relative to the sensitivity to decadal-scale interannual variations in vegetation density, we also carry out two additional simulations using observed normalized difference vegetation index (NDVI) from relatively low (1982,83) and high (1989,90) years to describe the seasonal phenology of the vegetation. In the past several centuries, large-scale land-cover change occurred primarily in temperate latitudes through conversion of forests and grassland to highly productive cropland and pasture. Several studies in the literature indicate that past changes in surface climate resulting from this conversion had a cooling effect owing to changes in vegetation morphology (increased albedo). In contrast, this study indicates that future land-cover change, likely to occur predominantly in the tropics and subtropics, has a warming effect governed by physiological rather than morphological mechanisms. The physiological mechanism is to reduce carbon assimilation and consequently latent relative to sensible heat flux resulting in surface temperature increases up to 2 °C and drier hydrologic conditions in locations where land cover was altered in the experiment. In addition, in contrast to an observed decrease in diurnal temperature range (DTR) over land expected with greenhouse warming, results here suggest that future land-cover conversion in tropics could increase the DTR resulting from decreased evaporative cooling during the daytime. For grid cells with altered land cover, the sensitivity of surface temperature to future anthropogenic land-cover change is generally within the range induced by decadal-scale interannual variability in vegetation density in temperate latitudes but up to 1.5 °C warmer in the tropics. [source]


    Myofascial Trigger Points, Neck Mobility, and Forward Head Posture in Episodic Tension-Type Headache

    HEADACHE, Issue 5 2007
    César Fernández-de-las-Peñas PT
    Objective.,To assess the differences in the presence of trigger points (TrPs) in head and neck muscles, forward head posture (FHP) and neck mobility between episodic tension-type headache (ETTH) subjects and healthy controls. In addition, we assess the relationship between these muscle TrPs, FHP, neck mobility, and several clinical variables concerning the intensity and the temporal profile of headache. Background.,TTH is a headache in which musculoskeletal disorders of the craniocervical region might play an important role in its pathogenesis. Design.,A blinded, controlled pilot study. Methods.,Fifteen ETTH subjects and 15 matched controls without headache were studied. TrPs in both upper trapezius, both sternocleidomastoids, and both temporalis muscles were identified according to Simons and Gerwin diagnostic criteria (tenderness in a hypersensible spot within a palpable taut band, local twitch response elicited by snapping palpation, and elicited referred pain with palpation). Side-view pictures of each subject were taken in both sitting and standing positions, in order to assess FHP by measuring the craniovertebral angle. A cervical goniometer was employed to measure neck mobility. All measures were taken by a blinded assessor. A headache diary was kept for 4 weeks in order to assess headache intensity, frequency, and duration. Results.,The mean number of TrPs for each ETTH subject was 3.7 (SD: 1.3), of which 1.9 (SD: 0.9) were active, and 1.8 (SD: 0.9) were latent. Control subjects only had latent TrPs (mean: 1.5; SD: 1). TrP occurrence between the 2 groups was significantly different for active TrPs (P < .001), but not for latent TrPs (P > .05). Differences in the distribution of TrPs were significant for the right upper trapezius muscles (P= .04), the left sternocleidomastoid (P= .03), and both temporalis muscles (P < .001). Within the ETTH group, headache intensity, frequency, and duration outcomes did not differ depending on TrP activity, whether the TrP was active or latent. The craniovertebral angle was smaller, ie, there was a greater FHP, in ETTH patients than in healthy controls for both sitting and standing positions (P < .05). ETTH subjects with active TrPs in the analyzed muscles had a greater FHP than those with latent TrPs in both sitting and standing positions, though differences were only significant for certain muscles. Finally, ETTH patients also showed lesser neck mobility than healthy controls in the total range of motion as well as in half-cycles (except for cervical extension), although neck mobility did not seem to influence headache parameters. Conclusions.,Active TrPs in the upper trapezius, sternocleidomastoid, and temporalis muscles were more common in ETTH subjects than in healthy controls, although TrP activity was not related to any clinical variable concerning the intensity and the temporal profile of headache. ETTH patients showed greater FHP and lesser neck mobility than healthy controls, although both disorders were not correlated with headache parameters. [source]


    Enhanced heat transfer analysis of latent functionally thermal fluid

    HEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 6 2004
    Fengwu Bai
    Abstract A physical model has been developed to analyze the enhanced heat transfer process of the latent functionally thermal fluid with microencapsulated phase-change material. The problem is solved by the combination of the finite difference method and the moving heat source method. The calculated results reveal that putting the phase-change microcapsules into the fluids can enhance the heat transfer capabilities of the mixture. The effects of capsule radius and concentration of particles are numerically predicted. The numerical results provide the theoretical basis for the application and design of the latent functionally thermal fluid. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(6): 383,392, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20025 [source]


    Royal ecclesiastical supremacy and the Restoration church*

    HISTORICAL RESEARCH, Issue 209 2007
    Jacqueline Rose
    The nature and extent of the royal supremacy over the Church of England proved contentious in Restoration England, especially when Charles II and James II sought to use their ecclesiastical prerogative to legitimate Nonconformist worship. Although the supremacy was a long-established institutional fact of the English church-state, it could be presented in diverse ways. This article outlines six versions of royal supremacy which were expressed, arguing that it was a contested and multiform entity which was manipulated by polemicists for their own purposes. Its location in the monarch alone, in crown-in-parliament, or in delegation to a lay vicegerent was unclear. Its character could be presented as purely jurisdictional or partly sacerdotal. The Declaration of Indulgence of 1672 led to the paradox of Nonconformists upholding the supremacy while the established church limited it. The political and religious insecurities of the Cabal era (1667,73) highlighted tensions and divergences which had been latent in concepts of the supremacy since its establishment under the Tudors. It is therefore vital to contextualize Restoration arguments in Reformation debates. Recognizing that ,royal',supremacy' was neither invariably monarchical nor inevitably absolute is significant for our understanding of the character of both the Restoration ecclesiastical polity and those who governed it. [source]


    Hydrogeologic controls on summer stream temperatures in the McKenzie River basin, Oregon

    HYDROLOGICAL PROCESSES, Issue 24 2007
    Christina Tague
    Abstract Stream temperature is a complex function of energy inputs including solar radiation and latent and sensible heat transfer. In streams where groundwater inputs are significant, energy input through advection can also be an important control on stream temperature. For an individual stream reach, models of stream temperature can take advantage of direct measurement or estimation of these energy inputs for a given river channel environment. Understanding spatial patterns of stream temperature at a landscape scale requires predicting how this environment varies through space, and under different atmospheric conditions. At the landscape scale, air temperature is often used as a surrogate for the dominant controls on stream temperature. In this study we show that, in regions where groundwater inputs are key controls and the degree of groundwater input varies in space, air temperature alone is unlikely to explain within-landscape stream temperature patterns. We illustrate how a geologic template can offer insight into landscape-scale patterns of stream temperature and its predictability from air temperature relationships. We focus on variation in stream temperature within headwater streams within the McKenzie River basin in western Oregon. In this region, as in other areas of the Pacific Northwest, fish sensitivity to summer stream temperatures continues to be a pressing environmental issue. We show that, within the McKenzie, streams which are sourced from deeper groundwater reservoirs versus shallow subsurface flow systems have distinct summer temperature regimes. Groundwater streams are colder, less variable and less sensitive to air temperature variation. We use these results from the western Oregon Cascade hydroclimatic regime to illustrate a conceptual framework for developing regional-scale indicators of stream temperature variation that considers the underlying geologic controls on spatial variation, and the relative roles played by energy and water inputs. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Identification and prevalence of CD8+ T-cell responses directed against Epstein-Barr virus-encoded latent membrane protein 1 and latent membrane protein 2

    INTERNATIONAL JOURNAL OF CANCER, Issue 1 2002
    Pauline Meij
    Abstract Epstein-Barr virus (EBV) is associated with several human malignancies that each show different viral gene expression profiles. In malignancies such as Hodgkin's disease and nasopharyngeal carcinoma only Epstein-Barr nuclear antigen 1 (EBNA1) and varying levels of latent membrane proteins 1 and 2 (LMP1 and -2) are expressed. Since endogenously expressed EBNA1 is protected from CTL recognition, LMP1 and LMP2 are the most likely target antigens for anti-tumor immunotherapy. Therefore, we sought to identify in a systematic way CD8+ T-cell responses directed against eptitopes derived from LMP1 and LMP2. Using IFN,-ELISPOT assays of interferon-, release, peripheral blood mononuclear cells (PBMC) of healthy donors were screened with peptide panels (15 mer overlapping by 10) spanning the LMP1 and LMP2 sequences of the prototype EBV strain B95.8. When positive responses were found, CD4+ or CD8+ T cells were depleted from donor PBMC to determine the origin of the responder population. We detected CD8+ T-cell responses to LMP1 in 9/50(18%) donors and to LMP2 in 15/28 (54%) donors. In addition to the already described epitopes, 3 new LMP1- and 5 new LMP2-derived CD8+ epitopes were identified. In most donors LMP1- and LMP2-specific CD8+ precursor frequencies were low compared with precursors against immunodominant EBV epitopes from latent (EBNA3A, -3B and -3C) and lytic cycle antigens. These results demonstrate that CD8+ memory T cell responses to LMP1 and especially to LMP2 do exist in Caucasians, albeit at low levels and could potentially be exploited for therapeutic use. © 2002 Wiley-Liss, Inc. [source]


    Simultaneous triple organ specific autoantibody profiling in adult patients with type 1 diabetes mellitus and their first-degree relatives,

    INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 3 2009
    S. Dagdelen
    Summary Aims:, We aimed to document prevalence and clinical presentations of seropositivities for glutamate decarboxylase (GAD)-antibody, celiac's disease (CD) and autoimmune thyroiditis (AIT) in adult patients with type 1 diabetes mellitus (T1DM), and their first-degree relatives. Methods:, Sixty-five patients with T1DM, 124 first-degree relatives and 65 healthy controls were screened for GAD-antibody, anti-thyroid peroxidase (ATPO), anti-thyroid stimulating hormone receptor (TSHR), anti-tissue transglutaminase and anti-gliadin antibodies in a matched case,control study. Results:, Prevalence of more than one seropositivity for CD-associated antibodies in T1DM-group is 6.0 times increased, compared with controls (p < 0.05). ATPO seropositivity is 5.3 times increased in T1DM group (p < 0.05), but TSHR antibody is comparable with controls (p > 0.05). Seropositivities for T1DM, AIT and CD are 4.3, 1.9 and 2.4 times more prevalent among first-degree relatives respectively, compared with controls (p < 0.05). Pathologically confirmed cases with CD among first-degree relatives were all identified at screening. In contrast, all of pathologically confirmed cases with CD in T1DM group, were either previously diagnosed or symptomatic at time of screening. In the group of patients with T1DM, 31% of seropositive cases for anti-ATPO were clinically latent for AIT, and 74% of ATPO (+) cases were identified at current screening study. Sixty-four per cent of ATPO (+) first-degree relatives were clinically latent for AIT, and 54% were identified at screening. Conclusion:, Type 1 diabetes mellitus, CD and AIT represent a significant overlap in an adult population with already-diagnosed T1DM and their first-degree relatives. With regard to clinical presentations, CD was less likely to be clinically silent than AIT among patients with T1DM. [source]


    Energetic and exergetic analysis of a domestic water tank with phase change material

    INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 3 2008
    C. Solé
    Abstract Although water is a cheap and effective medium for thermal energy storage, other options are currently being studied, to increase the storage density or to reduce the cost of the storage. The authors have been developing a system which combines the advantages of stratified sensible heat storage and latent, phase change heat storage; i.e. a hot water storage tank with stratification where a phase change material (PCM) is included into a spiral tube installed in the top of the tank. The PCM used was a granular PCM,graphite compound of about 90 vol.% of sodium acetate trihydrate and 10 vol.% graphite. This paper presents the results of an experimental investigation of the performance of the new storage concept, and of a conventional hot water storage tank for comparison. The data are further analysed with respect to the energetic and exergetic performance of the two systems. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    On the steady-state modelling of a two-stage evaporator system

    INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 10 2001
    M. N. A. Hawlader
    Abstract We develop and validate against experimental measurements a steady-state two-stage flooded refrigerant evaporator model for a heat pump drying system. A prototype two-stage heat pump dryer test facility was designed, built and instrumented to provide the required measurements for the validation of the model. Repeatability and data quality tests were conducted to evaluate the accuracy of measurements. Experimental data could be reproduced to within ±6.5 per cent of replicated air and refrigerant side measurements for the same evaporator's air inlet conditions while the discrepancy of energy balance at the air-side and refrigerant-side was observed to be within ±8.9 per cent. The two-stage evaporator model predicted the air-side total heat and latent heat transfer of the two-stage evaporator to within (,6.3 per cent, 7.6 per cent) and (,11.5 per cent, 9.5 per cent), respectively. On the refrigerant-side, the model enabled the calculation of the degree of superheat to within (,10.6 per cent, 1.7 per cent). The model has shown that there is significant improvement in the heat recovered from a two-stage evaporator system compared to a single evaporator system. In addition, the model demonstrated that the improvement in total heat recovery could be as high as 40 per cent over its base-value when the latent to total load at the two-stage evaporator is increased. Copyright © 2001 John Wiley & Sons, Ltd. [source]


    More Haste, Less Speed in Theology,

    INTERNATIONAL JOURNAL OF SYSTEMATIC THEOLOGY, Issue 3 2007
    JEAN-YVES LACOSTE
    Theological language lives urgently, under kerygmatic constraints, and yet is allowed delay for its tasks of interpretation. It searches for its words, forging a third language, which ,fulfils' the language of Jew and Greek and yet is a ,hard' language, tying the future of mankind to the fate of a single crucified man. It awakens a capacity for experience that is latent in us, yet violates our expectations. Hermeneutic demands take a new turn when speech becomes text. Languages age and die, but the meaning of their words does not. The world of past languages can be understood. The theologian is a translator, allowing the text to speak. Reading is preliminary to kerygmatic speech, and theology moves between the words of scripture and the words of immediate experience. The successful interpretation does not substitute itself for what it interprets, but makes us at home in the words and experience of the text. We learn it not as a mother-tongue but as a foreign language, and we discover that it is habitable. In introducing us to a universal reality mediated by that particular world, theology reveals us to ourselves, showing us that our continuity with it is stronger than any discontinuity. Theology must have its ,method', which is to acquire its own language by way of a detour through another language. Theological arguments are displacements. The speech that speaks the truth about essential things comes to meet us from its housing in particular languages and times. Which does not mean that the text may be re-written. What we understand in our own language is another language; what is made accessible to our world is another relation to the world. [source]


    Information and Economics in Fisher's Design of Experiments

    INTERNATIONAL STATISTICAL REVIEW, Issue 2 2007
    John Aldrich
    Summary In 1951 R. A. Fisher described what had been achieved in the 20th century so far: "we have learnt (i) To conserve in its statistical reduction the scientific information latent in any body of observations. (ii) To conduct experimental and observational inquiries so as to maximise the information obtained for a given expenditure." This paper asks what Fisher meant and, in particular, how he saw his work on experimental design as contributing to the objective of maximizing information for a given expenditure. The material examined ranges from detailed work on issues like "the information lost in measurement of error" to polemics against decision theory. Résumé En 1951 R.A. Fisher décrivait ce qui avait été accompli jusque là au 20ème siécle: "nous avons appris (i) à conserver dans sa réduction statistique l'information scientifique latente dans tout ensemble d'observations (ii) de conduire des investigations expérimentales et observationnelles de façon à maximiser l'information obtenue pour une dépense donnée." Cet article se demande ce que Fisher voulait dire et, en particulier, comment il voyait son travail de conception expérimentale comme contribution à l'objectif de maximiser l'information pour une dépense donnée. Les matériaux examinés vont des travaux détaillés sur des questions telles que "l'information perdue dans la mesure de l'erreur" jusqu'aux polémiques contre la théorie de la décision. [source]


    Regression modelling of correlated data in ecology: subject-specific and population averaged response patterns

    JOURNAL OF APPLIED ECOLOGY, Issue 5 2009
    John Fieberg
    Summary 1.,Statistical methods that assume independence among observations result in optimistic estimates of uncertainty when applied to correlated data, which are ubiquitous in applied ecological research. Mixed effects models offer a potential solution and rely on the assumption that latent or unobserved characteristics of individuals (i.e. random effects) induce correlation among repeated measurements. However, careful consideration must be given to the interpretation of parameters when using a nonlinear link function (e.g. logit). Mixed model regression parameters reflect the change in the expected response within an individual associated with a change in that individual's covariates [i.e. a subject-specific (SS) interpretation], which may not address a relevant scientific question. In particular, a SS interpretation is not natural for covariates that do not vary within individuals (e.g. gender). 2.,An alternative approach combines the solution to an unbiased estimating equation with robust measures of uncertainty to make inferences regarding predictor,outcome relationships. Regression parameters describe changes in the average response among groups of individuals differing in their covariates [i.e. a population-averaged (PA) interpretation]. 3.,We compare these two approaches [mixed models and generalized estimating equations (GEE)] with illustrative examples from a 3-year study of mallard (Anas platyrhynchos) nest structures. We observe that PA and SS responses differ when modelling binary data, with PA parameters behaving like attenuated versions of SS parameters. Differences between SS and PA parameters increase with the size of among-subject heterogeneity captured by the random effects variance component. Lastly, we illustrate how PA inferences can be derived (post hoc) from fitted generalized and nonlinear-mixed models. 4.,Synthesis and applications. Mixed effects models and GEE offer two viable approaches to modelling correlated data. The preferred method should depend primarily on the research question (i.e. desired parameter interpretation), although operating characteristics of the associated estimation procedures should also be considered. Many applied questions in ecology, wildlife management and conservation biology (including the current illustrative examples) focus on population performance measures (e.g. mean survival or nest success rates) as a function of general landscape features, for which the PA model interpretation, not the more commonly used SS model interpretation may be more natural. [source]


    Raman tweezers provide the fingerprint of cells supporting the late stages of KSHV reactivation

    JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 8b 2009
    Ossie F. Dyson
    Abstract Kaposi's sarcoma-associated herpesvirus (KSHV) has both latent and lytic phases of replication. The molecular switch that triggers a reactivation is still unclear. Cells from the S phase of the cell cycle provide apt conditions for an active reactivation. In order to specifically delineate the Raman spectra of cells supporting KSHV reactivation, we followed a novel approach where cells were sorted based on the state of infection (latent versus lytic) by a flow cytometer and then analysed by the Raman tweezers. The Raman bands at 785, 813, 830, 1095 and 1128 cm,1 are specifically altered in cells supporting KSHV reactivation. These five peaks make up the Raman fingerprint of cells supporting KSHV reactivation. The physiological relevance of the changes in these peaks with respect to KSHV reactivation is discussed in the following report. [source]


    STAT proteins: From normal control of cellular events to tumorigenesis,

    JOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2003
    Valentina Calò
    Signal transducers and activators of transcription (STAT) proteins comprise a family of transcription factors latent in the cytoplasm that participate in normal cellular events, such as differentiation, proliferation, cell survival, apoptosis, and angiogenesis following cytokine, growth factor, and hormone signaling. STATs are activated by tyrosine phosphorylation, which is normally a transient and tightly regulates process. Nevertheless, several constitutively activated STATs have been observed in a wide number of human cancer cell lines and primary tumors, including blood malignancies and solid neoplasias. STATs can be divided into two groups according to their specific functions. One is made up of STAT2, STAT4, and STAT6, which are activated by a small number of cytokines and play a distinct role in the development of T-cells and in IFN, signaling. The other group includes STAT1, STAT3, and STAT5, activated in different tissues by means of a series of ligands and involved in IFN signaling, development of the mammary gland, response to GH, and embriogenesis. This latter group of STATS plays an important role in controlling cell-cycle progression and apoptosis and thus contributes to oncogenesis. Although an increased expression of STAT1 has been observed in many human neoplasias, this molecule can be considered a potential tumor suppressor, since it plays an important role in growth arrest and in promoting apoptosis. On the other hand, STAT3 and 5 are considered as oncogenes, since they bring about the activation of cyclin D1, c-Myc, and bcl-xl expression, and are involved in promoting cell-cycle progression, cellular transformation, and in preventing apoptosis. J. Cell. Physiol. 197: 157,168, 2003© 2003 Wiley-Liss, Inc. [source]


    Fatal HHV6 infection in an immunocompromised patient presenting with skin involvement

    JOURNAL OF CUTANEOUS PATHOLOGY, Issue 2 2010
    Anjela Galan
    Infection with human herpesvirus-6 (HHV6) has a broad distribution in the human population, with a seroprevalence approaching 100% worldwide. Primary infection takes place during childhood, after which the virus remains latent mostly in lymphocytes and monocytes at various sites. Immunosuppression can result in viral reactivation, associated with clinical sequelae and even death. We report a case of a disseminated HHV6 infection in a 53-year-old patient, who was immunocompromised after allogeneic bone marrow transplant treatment for acute lymphocytic leukemia. Initially, he presented with a macular eruption of the skin, followed by involvement of other sites. Histopathologic analysis of skin biopsies revealed superficial perivascular large atypical mononuclear cells with intranuclear and intracytoplasmic inclusions. Most affected cells labeled with antibodies to CD3 and CD43 as lymphocytes, and some labeled with CD68 as macrophages. Polymerase chain reaction (PCR) studies of the blood, skin, liver, colon, cerebrospinal fluid and brain were positive for HHV6 virus. Additionally, the serologic titers for HHV6 were high. Viral particles were also detected by electron microscopy (EM) in the colon. Although rare, HHV6 virus may be an important pathogen in immunocompromised patients, and may present initially in the skin. Awareness of this infection is critical to diagnosis in acute settings. Galan A, McNiff JM, Nam Choi J and Lazova R. Fatal HHV6 infection in an immunocompromised patient presenting with skin involvement. [source]


    A stochastic modelling approach to describing the dynamics of an experimental furunculosis epidemic in Chinook salmon, Oncorhynchus tshawytscha (Walbaum)

    JOURNAL OF FISH DISEASES, Issue 2 2007
    H Ogut
    Abstract A susceptible-infected-removed (SIR) stochastic model was compared to a susceptible-latent-infectious-removed (SLIR) stochastic model in terms of describing and capturing the variation observed in replicated experimental furunculosis epidemics, caused by Aeromonas salmonicida. The epidemics had been created by releasing a single infectious fish into a group of susceptible fish (n = 43) and progress of the epidemic was observed for 10 days. This process was replicated in 70 independent groups. The two stochastic models were run 5000 times and after every run and every 100 runs, daily mean values of each compartment were compared to the observed data. Both models, the SIR model (R2 = 0.91), and the SLIR model (R2 = 0.90) were successful in predicting the number of fish in each category at each time point in the experimental data. Moreover, between-replicate variability in the stochastic model output was similar to between-replicate variability in the experimental data. Generally, there was little change in the goodness of fit (R2) after 200 runs in the SIR model whereas 500 runs were necessary to have stable predictions with the SLIR model. In the SIR model, on an individual replicate basis, ,80% of 5000 simulated replicates had R2 = 0.7 and above, whereas this ratio was slightly higher (82%) with the SLIR model. In brief, both models were equally effective in predicting the observed data and its variance but the SLIR model was advantageous because it differentiated the latent, i.e. infected but not having the ability to discharge pathogen, from the infectious fish. [source]


    Oviposition strategies employed by the western spruce budworm: tests of predictions from the phylogenetic constraints hypothesis

    AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2003
    Kathryn J. Leyva
    Abstract 1,Predictions from the Phylogenetic Constraints Hypothesis were tested for the first time in an eruptive forest Lepidopteran species, the western spruce budworm. 2,In previous work, we established that western spruce budworm females exhibit oviposition preferences with regard to tree age, tree vigour and host species. However, there was no evidence to support a link between oviposition preference and larval performance, which supports the Phylogenetic Constraints Hypothesis. 3,Our preference data led us to test whether female budworms use oviposition strategies to select the sites where they lay their egg masses. Our experiments were designed to make direct comparisons between latent and eruptive insect herbivores with respect to two oviposition behaviours: egg retention and avoidance of conspecifics. This type of research has not previously been conducted on any eruptive forest Lepidopteran. 4,Female budworms retained eggs instead of laying them on less preferred hosts in two of three experiments, but the percentage of eggs they retained was significantly less compared to latent insect herbivores. 5,In addition, female budworms actively avoided oviposition in areas with the highest density of conspecific egg masses, but they laid egg masses in all the other locations provided. This contrasts with the pattern seen in latent insect herbivores, which consistently avoid laying their eggs near any sites already used by conspecifics. 6,Our research indicates that there are extreme differences between latent and eruptive insect herbivores with respect to egg retention and avoidance of conspecifics, thus supporting the Phylogenetic Constraints Hypothesis. [source]


    Patterns of antibodies against latent and lytic antigens of human herpesvirus 8 in an endemic population and patients with Kaposi's sarcoma in Mozambique

    JOURNAL OF MEDICAL VIROLOGY, Issue 9 2010
    Adele Caterino-de-Araujo
    Abstract The patterns of antibodies against latent and lytic antigens of human herpesvirus 8 (HHV-8) were assessed using immunofluorescence assays of samples from 155 persons seropositive for HHV-8 seen at public health centers and 24 patients with Kaposi's sarcoma (KS) from Mozambique. Of the 155 persons without KS, 48 (31%) had antibodies against latent antigens only, 29 (18.7%) had antibodies against lytic antigens only, and 78 (50.3%) had antibodies against both types of antigen. The HHV-8 antibody titer tended to increase with age until age 40, after which it began to decrease. High titers of antibodies against latent and lytic antigens of HHV-8 were detected mostly in persons co-infected with HIV, and these increased titers could have a predictive value. All patients with KS except four patients who were seronegative for HHV-8 had elevated titers of HHV-8 antibodies, predominantly against latent antigens. The data suggest the potential for an increase in the development of KS in this endemic area for HHV-8. J. Med. Virol. 82:1576,1581, 2010. © 2010 Wiley-Liss, Inc. [source]


    Asymptomatic reactivation and shed of infectious varicella zoster virus in astronauts

    JOURNAL OF MEDICAL VIROLOGY, Issue 6 2008
    Randall J. Cohrs
    Abstract Varicella zoster virus (VZV) causes varicella (chickenpox), after which virus becomes latent in ganglia along the entire neuraxis. Virus reactivation produces zoster (shingles). Infectious VZV is found in vesicles of patients with zoster and varicella, but virus shed in the absence of disease has not been documented. VZV DNA was previously detected in saliva of astronauts during and after spaceflight, a uniquely stressful environment in which cell mediated immunity (CMI) is temporally dampened. The decline in CMI to VZV associated with zoster led to the hypothesis that infectious VZV would also be present in the saliva of astronauts subjected to stress of spaceflight. Herein, not only was the detection of salivary VZV DNA associated with spaceflight validated, but also infectious virus was detected in saliva from 2 of 3 astronauts. This is the first demonstration of shed of infectious VZV in the absence of disease. J. Med. Virol. 80:1116,1122, 2008. © 2008 Wiley-Liss, Inc. [source]


    Latent and lytic infection of isolated guinea pig enteric ganglia by varicella zoster virus

    JOURNAL OF MEDICAL VIROLOGY, Issue S1 2003
    Jason J. Chen
    Abstract Varicella zoster virus (VZV) has been demonstrated to infect guinea pig enteric neurons in vitro. Latent infection of isolated enteric neurons is established when the cultures predominantly consist of neurons and they are exposed to cell-free VZV. Neurons harboring latent infection survive for weeks in vitro and express mRNA encoding ORFs 4, 21, 29, 40, 62, and 63, but not 14(gC) or 68 (gE) (although DNA encoding the glycoproteins is present). The expressed proteins are the same as those that are also expressed in human sensory neurons harboring latent VZV. In addition to mRNA, the immunoreactivities of ORFs 4, 21, 29, 62, and 63 can be detected. ORF 62 and 29 proteins are cytoplasmic and not intranuclear. VZV does not preferentially infect and/or become latent in intrinsic enteric primary afferent neurons indicating that the virus is latent in these neurons. Lytic infection occurs when mixed cultures of neurons and non-neuronal cells of the bowel wall are exposed to cell-free VZV or when isolated enteric neurons are exposed to cell-associated VZV. When lytic infection occurs, enteric neurons die within 48 hr. Prior to their death, neurons express VZV glycoproteins, including gE and gB, and ORF 62 and 29 proteins are intranuclear. This new animal model should facilitate studies of VZV latency and the efficacy of therapies designed to prevent VZV infecion, latency, and reactivation. J. Med. Virol. 70:S71,S78, 2003. © 2003 Wiley-Liss, Inc. [source]