bluuebunny/crossref_metadata_2025_split huggingface dataset:
ESTIMATION OF THE CONCENTRATION PARAMETERS OF THE FISHER MATRIX DISTRIBUTION ON 50(3) AND THE BINGHAM DISTRIBUTION ONSq,q≥ 2
Authors: Wood Andrew T.A. 
Published: February 2008

SummaryTwo procedures are considered for estimating the concentration parameters of the Fisher matrix distribution for rotations or orientations in three dimensions. The first is maximum likelihood. The use of a convenient 1‐dimensional integral representation of the normalising constant, which greatly simplifies the computation, is suggested. The second approach exploits the equivalence of the Fisher distribution for rotations in three dimensions, and the Bingham distribution for axes in four dimensions. We describe a pseudo likelihood procedure which works for the Bingham distribution in any dimension. This alternative approach does not require numerical integration. Results on the asymptotic efficiency of the pseudo likelihood estimator relative to the maximum likelihood estimator are given, and the two estimators are compared in the analysis of a well‐known vectorcardiography dataset.
PARAMETER ESTIMATION FOR LOW‐ORDER AUTO‐REGRESSIVE MODELS WITH MISSING VALUES
Authors: Segal Mark R. , Rosner Bernard , Liou Albert G.S. , Schouten Jan P. 
Published: February 2008

SummaryLongitudinal data analysis in epidemiological settings is complicated by large multiplicities of short time series and the occurrence of missing observations. To handle such difficulties Rosner & Muñoz (1988) developed a weighted non‐linear least squares algorithm for estimating parameters for first‐order autoregressive (AR1) processes with time‐varying covariates. This method proved efficient when compared to complete case procedures. Here that work is extended by (1) introducing a different estimation procedure based on the EM algorithm, and (2) formulating estimation techniques for second‐order autoregressive models. The second development is important because some of the intended areas of application (adult pulmonary function decline, childhood blood pressure) have autocorrelation functions which decay more slowly than the geometric rate imposed by an AR1 model. Simulation studies are used to compare the three methodologies (non‐linear, EM based and complete case) with respect to bias, efficiency and coverage both in the presence and in the absence of time‐varying covariates. Differing degrees and mechanisms of missingness are examined. Preliminary results indicate the non‐linear approach to be the method of choice: it has high efficiency and is easily implemented. An illustrative example concerning pulmonary function decline in the Netherlands is analyzed using this method.
ON THE INDEPENDENCE OF THE SAMPLE MEAN AND TRANSLATION‐INVARIANT STATISTICS FOR MATRIX NORMAL DISTRIBUTIONS
Authors: M.YOUNG DEAN , ODELL PATRICK L. , SEAMAN JOHN W. 
Published: February 2008

SummaryWe present an explicit characterization of the joint dependency structure of ann×pmatrix normal random matrix such that the p‐dimensional sample mean vector is independent of all translation invariant statistics.
A LIKELIHOOD APPROACH TO SCALING EXAMINATION MARKS
Authors: Biggins J.D. , Yue K.K. 
Published: February 2008

SummaryOne of the common approaches to the problem of scaling and combining examination marks has its roots in the least squares tradition. In this framework, examiners' preconceptions about the transformations must be dealt with in an adhocway. This paper investigates another, likelihood‐based, approach which allows preconceptions to be handled by standard Bayesian techniques. The likelihood and least squares approaches are not directly parallel (essentially because a Jacobian must be included in the likelihood). Nonetheless, the device of introducing fictitious candidates to deal with prior beliefs in the least squares set‐up can be understood in a Bayesian sense.
THE ROBUSTNESS OF BINARY AND NON‐BINARY BALANCED NESTED ROW‐COLUMN DESIGNS UNDER THE UNAVAILABILITY OF BLOCKS: A COMPARISON
Authors: Uddin Nizam , Whittinghill Dexter C. 
Published: February 2008

SummaryIn cases where both exist, the balanced, binary nested row‐column designs are known to be inferior to a class of balanced non‐binary designs. However, if it is possible for blocks of observations to become unavailable after an experiment has commenced, a binary nested row‐column design may possibly be better than a non‐binary one. This paper investigates the robustness of binary and non‐binary variance‐balanced nested row‐column designs to the unavailability of one or more blocks of observations. Robustness is measured through the C‐matrices of the designs resulting from removing blocks, using optimality criteria such as A‐, D‐, E‐ and MV‐optimality.
A NOTE ON COMPETING VARIANCE ESTIMATORS IN RANDOMISED RESPONSE SURVEYS
Authors: Chaudhuri Arijit , Maiti Tapabrata , Roy Debesh 
Published: February 2008

SUMMARYWhen gathering randomised rather than direct responses on a variable of interest relating to sensitive issues, one may use a modified version of the well‐known generalised regression predictor of a finite population total. To construct confidence intervals, this paper proposes four alternative variance estimators – modifications to those usable with direct responses – and examines their relative efficiencies through simulations from simple super‐population models.
DETERMINATION OF DOMAINS OF ATTRACTION BASED ON A SEQUENCE OF MAXIMA
Authors: Wang J.Z. , Cooke P. , Li S. 
Published: February 2008

SummarySuppose that the maximum of a random sample from a distributionF(x) may be obtained in each ofkequally spaced observation periods. This paper proposes a test to determine the domain of attraction ofF(x), and investigates the properties when the sample size is very large and perhaps unknown andkis fixed and small. The test statistic is a function of the spacings between the order statistics based on the sequence of maxima and is suggested by reference to one studied previously when inference was based on the largestkobservations of a random sample. A Monte Carlo study shows that the proposed test is more powerful than its main competitor. The test is illustrated by two examples.
ON THE NUMBER OF RECORDS NEAR THE MAXIMUM
Authors: Pakes Anthony G. , Steutel Fred W. 
Published: February 2008

summaryRecent work has considered properties of the number of observationsXj, independently drawn from a discrete law, which equal the sample maximumX(n)The natural analogue for continuous laws is the numberKn(a) of observations in the interval (X(n)–a,X(n)], wherea> 0. This paper derives general expressions for the law, first moment, and probability generating function ofKn(a), mentioning examples where evaluations can be given. It seeks limit laws forn→ and finds a central limit result whenais fixed and the population law has a finite right extremity. Whenever the population law is attracted to an extremal law, a limit theorem can be found by lettingadepend onnin an appropriate manner; thus the limit law is geometric when the extremal law is the Gumbel type. With these results, the paper obtains limit laws for ‘top end’ spacingsX(n)‐X(n‐j)withjfixed.
TIGHT UPPER CONFIDENCE LIMITS FROM DISCRETE DATA
Authors: Kabaila Paul , Lloyd Chris J. 
Published: February 2008

summaryConsider the problem of finding an upper 1 –α confidence limit for a scalar parameter of interest ø in the presence of a nuisance parameter vector θ when the data are discrete. Approximate upper limitsTmay be found by approximating the relevant unknown finite sample distribution by its limiting distribution. Such approximate upper limits typically have coverage probabilities below, sometimes far below, 1 –α for certain values of (θ, ø). This paper remedies that defect by shifting the possible valuestofTso that they are as small as possible subject both to the minimum coverage probability being greater than or equal to 1 –α, and to the shifted values being in the same order as the unshiftedts. The resulting upper limits are called ‘tight’. Under very weak and easily checked regularity conditions, a formula is developed for the tight upper limits.
ERROR BOUNDS FOR CALCULATION OF THE GITTINS INDICES
Authors: Wang You‐Gan 
Published: February 2008

summaryFor a wide class of semi‐Markov decision processes the optimal policies are expressible in terms of the Gittins indices, which have been found useful in sequential clinical trials and pharmaceutical research planning. In general, the indices can be approximated via calibration based on dynamic programming of finite horizon. This paper provides some results on the accuracy of such approximations, and, in particular, gives the error bounds for some well known processes (Bernoulli reward processes, normal reward processes and exponential target processes).
THE CUBE OF A LOGISTIC DISTRIBUTION IS INDETERMINATE
Authors: LIN G.D. , HUANG J.S. 
Published: February 2008

SummaryIt is known that most distributions are uniquely determined by their moments. Exceptions exist, but are believed to be rare among those we encounter in everyday life applications. We add one more to the rare collection, and suggest that indeterminate distributions are perhaps more prevalent than is commonly perceived.
A Polyocular Framework for Research on Multifunctional Farming and Rural Development
Authors: Noe Egon , Alrøe Hugo Fjelsted , Langvad Anne Mette S. 
Published: February 2008

AbstractThe paradox of multifunctionality is that, on the one hand, the specialised functionalities of agriculture arise only because of the functional differentiation of social systems and scientific disciplines and, on the other hand, multifunctionality can enter only as a way to mediate between conflicts, interests and fragmented knowledge when different functions and observations of functions combine. The aim of this article is to contribute to a theoretical and methodological platform for multidisciplinary research on multifunctional farming. With the notions of polyocular cognition and polyocular communication we introduce a second order, interdisciplinary communication process that can meet the challenge of creating a shared view on multifunctional farming. Polyocular communication must be based on rules other than the rules of the disciplines involved. Whereas disciplinary communication is about providing consistent, efficient and precise knowledge in the context of a sharply delimited research world, polyocular communication is about extending a multidimensional space of understanding.
Exploring Farmers' Cultural Resistance to Voluntary Agri‐environmental Schemes
Authors: Burton Rob. J.F. , Kuczera Carmen , Schwarz Gerald 
Published: February 2008

AbstractStudies throughout Europe have suggested that voluntary agri‐environmental programmes often engender very little change in attitudes towards productivist agriculture among conventional farming communities. This study examines why this may be so, using case studies from Hessen, Germany and Aberdeenshire, Scotland. By constructing a conceptual framework based on Bourdieu's notions of capital we explore how farming activities are able to generate symbolic capital, and compare this with the symbolic value of conservation work. We find that voluntary agri‐environmental work returns little symbolic capital to farmers as, by prescribing management practices and designating specific areas for agri‐environmental work, such schemes fail to allow farmers to develop or demonstrate skilled role performance – thus inhibiting the development of embodied cultural capital. We conclude by suggesting that entrepreneurial production‐target based agri‐environmental schemes may be ultimately more effective in changing long‐term behaviour.
Effect of food on the antiviral activity of didanosine enteric‐coated capsules: a pilot comparative study*
Authors: Hernández‐Novoa B , Antela A , Gutiérrez C , Pérez‐Molina JA , Pérez‐Elías MJ , Dronda F , Moreno A , Casado JL , Page C , Pumares M , Galán JC , Moreno S 
Published: February 2008

ObjectivesTo determine the effect of food on the antiviral activity of enteric‐coated (EC) capsules of didanosine (ddI).MethodsWe conducted a pilot, randomized, open‐label study of 28‐day ddI‐EC capsules monotherapy‐administered in a fasted state (group 1, n=11) or with food (group 2, n=10) to treatment‐naïve chronically HIV‐1‐infected individuals. To assess the antiviral efficacy, HIV‐1 RNA was determined at baseline, day 3, day 7 and weekly thereafter. The area under the HIV‐1 RNA curve minus baseline weighted by time (AUCMB/day) was calculated.ResultsMean baseline HIV‐1 RNA was 4.2 log10 copies/mL in group 1 and 3.8 log10 copies/mL in group 2. After 28 days, the mean HIV‐1 RNA reduction was 0.99 log10 copies/mL [95% confidence interval (CI) 0.45–1.53] for group 1 and 0.89 log10 copies/mL (95% CI 0.38–1.40) for group 2. AUCMB/day values were 0.775 log10 copies/mL (95% CI 0.33–1.22) and 0.774 log10 copies/mL (95% CI 0.48–1.07), respectively, showing no difference in the rate of decrease of HIV‐1 RNA (P=0.995). Mean ddI plasma levels at day 28 were 0.0234 mg/L for group 1 and 0.0227 mg/L for group 2 (P=0.96).ConclusionsIn this pilot study, the administration of food did not have any significant effect on the antiviral activity of ddI‐EC capsules.
An audit of viral load in one clinical population to describe features of viraemic patients on antiretroviral therapy
Authors: Madge S , Smith CJ , Lampe F , Sabin CA , Youle M , Johnson MA , Phillips AN 
Published: February 2008

ObjectivesTo assess the prevalence of an undetectable viral load (VL) (<50 HIV‐1 RNA copies/mL) in a clinical population and to identify those viraemic and at risk of failing antiretroviral therapy (ART).MethodsAn audit of a complete clinical population on 1 January 2005 via a clinical database and clinical note review.ResultsOn 1 January 2005, 1910 patients were under care; 1229/1332 (92%) of those exposed to ART for >16 weeks had a VL of <50 copies/mL. We examined 49/56 case notes of viraemic patients to identify explanations for viraemia. Common reasons included previous initial mono‐ or dual therapy, adherence problems, more advanced HIV disease, concomitant medications, physical and mental health issues and being less well linked into the service. A review of these patients' current status on 1 April 2007 showed that six of the 49 had since died. However, of those still alive, 20 (47%) had a VL <500 copies/mL.ConclusionsThe proportion of patients on ART with detectable viraemia is low in current clinical practice. New drugs may help those who are failing because of resistance. However, there is a small minority of patients who, for various reasons, appear unable to maintain sufficient adherence to ART.
Exon Deletion in the Non‐catalytic Domain of eIF2Bɛ Due to a Splice Site Mutation Leads to Infantile Forms of CACH/VWM with Severe Decrease of eIF2B GEF Activity
Authors: Horzinski L. , Gonthier C. , Rodriguez D. , Scherer C. , Boespflug‐Tanguy O. , Fogli A. 
Published: February 2008

SummaryThe CACH/VWM syndrome is an autosomal recessive leukodystrophy characterized by a broad spectrum of clinical presentations and by diffuse cavitary degeneration of the white matter on MRI. Mutations responsible for this disorder are missense or frameshift mutations occurring in the five genes (EIF2B1‐5) that encode the translation eukaryotic initiation factor eIF2B. We found that a patient with infantile CACH/VWM carries a mutation in the acceptor splice site of EIF2B5 exon 6. In lymphoblastoid cells of the patient, we detected an abnormal EIF2B5 transcript in which exon 6 was absent, however, the predicted protein product lacking part of the non‐catalytic domain encoded by exon 6 was not detected. The eIF2B GEF activity was severely decreased. These data support the importance of the non‐catalytic domain of the eIF2Bɛ subunit in the eIF2B complex formation and activity.
Migration Waves to the Baltic Sea Region
Authors: Lappalainen T. , Laitinen V. , Salmela E. , Andersen P. , Huoponen K. , Savontaus M.‐L. , Lahermo P. 
Published: February 2008

SummaryIn this study, the population history of the Baltic Sea region, known to be affected by a variety of migrations and genetic barriers, was analyzed using both mitochondrial DNA and Y‐chromosomal data. Over 1200 samples from Finland, Sweden, Karelia, Estonia, Setoland, Latvia and Lithuania were genotyped for 18 Y‐chromosomal biallelic polymorphisms and 9 STRs, in addition to analyzing 17 coding region polymorphisms and the HVS1 region from the mtDNA. It was shown that the populations surrounding the Baltic Sea are genetically similar, which suggests that it has been an important route not only for cultural transmission but also for population migration. However, many of the migrations affecting the area from Central Europe, the Volga‐Ural region and from Slavic populations have had a quantitatively different impact on the populations, and, furthermore, the effects of genetic drift have increased the differences between populations especially in the north. The possible explanations for the high frequencies of several haplogroups with an origin in the Iberian refugia (H1, U5b, I1a) are also discussed.
Two conventional protein kinase C isoforms, α and βI, are involved in the ATP‐induced activation of volume‐regulated anion channel and glutamate release in cultured astrocytes
Authors: Rudkouskaya Alena , Chernoguz Artur , Haskew‐Layton Renée E. , Mongin Alexander A. 
Published: February 2008

AbstractVolume‐regulated anion channels (VRACs) are activated by cell swelling and are permeable to inorganic and small organic anions, including the excitatory amino acids glutamate and aspartate. In astrocytes, ATP potently enhances VRAC activity and glutamate release via a P2Y receptor‐dependent mechanism. Our previous pharmacological study identified protein kinase C (PKC) as a major signaling enzyme in VRAC regulation by ATP. However, conflicting results obtained with potent PKC blockers prompted us to re‐evaluate the involvement of PKC in regulation of astrocytic VRACs by using small interfering RNA (siRNA) and pharmacological inhibitors that selectively target individual PKC isoforms. In primary rat astrocyte cultures, application of hypoosmotic medium (30% reduction in osmolarity) and 20 μM ATP synergistically increased the release of excitatory amino acids, measured with a non‐metabolized analog ofl‐glutamate,d‐[3H]aspartate. Both Go6976, the selective inhibitor of Ca2+‐sensitive PKCα, βI/II, and γ, and MP‐20‐28, a cell permeable pseudosubstrate inhibitory peptide of PKCα and βI/II, reduced the effects of ATP ond‐[3H]aspartate release by ∼45–55%. Similar results were obtained with a mixture of siRNAs targeting rat PKCα and βI. Surprisingly, down‐regulation of individual α and βI PKC isozymes by siRNA was completely ineffective. These data suggest that ATP regulates VRAC activity and volume‐sensitive excitatory amino acid release via cooperative activation of PKCα and βI.
Trauma, PTSD and personality: the relationship between prolonged traumatization and personality impairments
Authors: Daud Atia , Klinteberg Britt af , Rydelius Per‐Anders 
Published: February 2008

Objective:  Chronic post‐traumatic stress disorder (PTSD) has been associated with personality impairments involving externalized and internalized psychopathology. This study has explored the association between PTSD symptoms as consequences of prolonged torture experiences or early childhood trauma exposure and personality traits.Method:  One hundred and sixty‐one men were included: 36 Iraqi men refugees (mean age = 43.9, SD = 8.7) who had longstanding torture experiences as adults; 42 Swedish prisoners (mean age = 33.8, SD = 7), with early childhood trauma exposure; 31 Arab men refugees (mean age = 41.8, SD = 8.9) without self‐reported torture or violence experiences; 52 non‐traumatized Swedish males (mean age = 39.3, SD = 5.5). They were assessed for symptoms of PTSD or PTSD hypothetical clusters. Personality profile was assessed by the Karolinska Scales of Personality (KSP). Factor analysis with varimax rotation was conducted and yielded three factors: externalized, internalized and avoidance domains.Results:  Individuals who suffered prolonged torture experiences or had early childhood trauma exposure showed impaired personality profiles in internalized and externalized domains. Individuals with or without PTSD showed significant differences p < 0.05 concerning: internalized, externalized and avoidance. anova and post‐hoc analysis according to Scheffé showed that the prolonged torture group > early childhood trauma exposure > nontraumatized group.Conclusion:  Prolonged torture experiences or early trauma exposure may impair personality formation by enhancing the effects of cognitive, affective and behavioural vulnerabilities.
Formation of garnet polycrystals during metamorphic crystallization
Authors: WHITNEY D. L. , GOERGEN E. T. , KETCHAM R. A. , KUNZE K. 
Published: February 2008

AbstractGarnet polycrystals may form throughout the metamorphic history of a rock, starting at the earliest stages of garnet growth when closely spaced nuclei coalesce. In mica schist from Townshend Dam, VT, electron back‐scattered diffraction (EBSD) analysis shows that garnet polycrystals possess two or more distinct lattice orientations separated by high‐angle boundaries (28–61°). The minimum rotational displacements required to bring these lattice orientations into concordance with each other are commonly normal to the same low‐energy planes that occur as crystal faces of euhedral garnet. There is no evidence for intracrystalline deformation, and the polycrystals therefore probably represent individual garnet crystals that coalesced during growth. The boundaries cross‐cut growth zoning and inclusion trails of the polycrystals, indicating that early‐formed polycrystals, once coalesced, behave chemically and physically as single crystals. Statistical analysis of a 3D, high‐resolution X‐ray computed tomographic data set of a large sample (912 cm3) of a Townshend Dam schist, combined with microprobe and EBSD analyses of garnet, are consistent with a high degree of clustering at all stages of garnet growth. The formation and prevalence of polycrystals implies that garnet nuclei impinged on each other and coalesced, and that coalescence was a common feature throughout garnet growth in the rock.
Entrepreneurship—Hop
Authors: Gartner William B. 
Published: February 2008

“The future is not coming to you. You fetch it! Or it goes away. Who wins and who gains from a failure Depends on who falls and who stays. It all has to do with perspective What prism that you use for a scatter. But remember: Humble or arrogant May be a bifocal matter.” (Wahlbin, 2005) This is a “mash–up” of some ideas on entrepreneurship scholarship using rhymes. The challenge was to compare and contrast special issue articles along national lines. The pondering of each country's imperative comes out through this “hip–hop” perspective. Please be assured when you read this that these rhymes are serious. There are important issues that scholars’ interest must pay, so do not let this format get in the way, using this poem as a start, of exploring entrepreneurship as science and art. Ideas from each country are beyond differences in methods quantitative and quality: Issues philosophical, rhetorical, historical, and current are the basis for the entrepreneurship field's ferment. Pay you back with interest (Clarke, Hicks, & Nash, 1966)