bluuebunny/crossref_metadata_2025 huggingface dataset:
FRACTIONAL SUPERSYMMETRIC QUANTUM MECHANICS, TOPOLOGICAL INVARIANTS AND GENERALIZED DEFORMED OSCILLATOR ALGEBRAS
Authors: QUESNE C.
Published: March 2003

Fractional supersymmetric quantum mechanics of order λ is realized in terms of the generators of a generalized deformed oscillator algebra and a ℤλ-grading structure is imposed on the Fock space of the latter. This realization is shown to be fully reducible with the irreducible components providing λ sets of minimally bosonized operators corresponding to both unbroken and broken cases. It also furnishes some examples of ℤλ-graded uniform topological symmetry of type (1, 1, …, 1) with topological invariants generalizing the Witten index.
NONCONFORMING MIXED ELEMENTS FOR ELASTICITY
Authors: ARNOLD DOUGLAS N. , WINTHER RAGNAR
Published: March 2003

We construct first-order, stable, nonconforming mixed finite elements for plane elasticity and analyze their convergence. The mixed method is based on the Hellinger–Reissner variational formulation in which the stress and displacement fields are the primary unknowns. The stress elements use polynomial shape functions but do not involve vertex degrees of freedom.
SPECIAL SOLUTION STRATEGIES INSIDE A SPECTRAL ELEMENT OCEAN MODEL
Authors: DOUGLAS CRAIG C. , HAASE GUNDOLF , ISKANDARANI MOHAMED , REITZINGER STEFAN
Published: March 2003

We present three ideas to accelerate the filtering process used in the multilayered Spectral Element Ocean Model (SEOM). We define and analyze a Schur complement preconditioner, a lumping of small entries and an algebraic multigrid (AMG) algorithm. and a algebraic multigrid with patch smoothing algorithm. Finally, we analyze the impact of variations of the Schur complement and AMG methods on memory and computer time.
SPATIAL ANALYTICITY PROPERTIES OF NONLINEAR WAVES
Authors: BONA JERRY L. , GRUJIĆ ZORAN
Published: March 2003

In this paper, we study spatial analyticity properties of two classes of equations modeling unidirectional waves in nonlinear, dispersive media, namely KdV-type equations and BBM-type equations. The commentary begins with KdV-type equations and the observation that, for a class of such equations, boundedness of a solution suffices to maintain analyticity and so loss of analyticity detects loss of L∞-regularity. For a larger class of KdV-type equations, the same conclusion is valid provided that L∞-boundedness of a solution is replaced by [Formula: see text]-boundedness. It is also shown that these nonlinear dispersive wave equations are amenable to Gevrey-class analysis based on the boundedness of a Sobolev norm. This analysis yields an explicit lower bound on the possible rate of decrease in time of the uniform radius of analyticity of a solution in terms of the assumed Sobolev bound and the Gevrey-norm of the initial data. Attention is then shifted to BBM-type equations. It is shown that, regardless of the strength of the nonlinearity, a solution starting in a Gevrey space remains in this class for all time. Moreover, a lower bound on the possible rate of decrease in time of the uniform analyticity radius has temporal asymptotics that are independent of the degree of the nonlinearity, and so apparently determined in the main by the dispersion.
APPROXIMATION BY PIECEWISE CONSTANT FUNCTIONS IN A BV METRIC
Authors: BĚLÍK PAVEL , LUSKIN MITCHELL
Published: March 2003

We study the approximation properties of piecewise constant functions with respect to triangular and rectangular finite elements in a metric defined on functions of bounded variation. We apply our results to a thin film model for martensitic crystals and to the approximation of deformations with microstructure.
AN ANALYSIS OF THREE DIFFERENT FORMULATIONS OF THE DISCONTINUOUS GALERKIN METHOD FOR DIFFUSION EQUATIONS
Authors: ZHANG MENGPING , SHU CHI-WANG
Published: March 2003

In this paper we present an analysis of three different formulations of the discontinuous Galerkin method for diffusion equations. The first formulation yields an numerically inconsistent and weakly unstable scheme, while the other two formulations, the local discontinuous Galerkin approach and the Baumann–Oden approach, give stable and convergent results. When written as finite difference schemes, such a distinction among the three formulations cannot be easily analyzed by the usual truncation errors, because of the phenomena of supraconvergence and weak instability. We perform a Fourier type analysis and compare the results with numerical experiments. The results of the Fourier type analysis agree well with the numerical results.
Changes in Brain Natriuretic Peptide and Norepinephrine Over Time and Mortality and Morbidity in the Valsartan Heart Failure Trial (Val-HeFT)
Authors: Anand Inder S. , Fisher Lloyd D. , Chiang Yann-Tong , Latini Roberto , Masson Serge , Maggioni Aldo P. , Glazer Robert D. , Tognoni Gianni , Cohn Jay N.
Published: March 2003

Background—

Neurohormones are considered markers of heart failure progression. We examined whether changes in brain natriuretic peptide (BNP) and norepinephrine (NE) over time are associated with corresponding changes in mortality and morbidity in the Valsartan Heart Failure Trial.

Methods and Results—

Plasma BNP and NE were measured before randomization and during follow-up in ≈4300 patients in the Valsartan Heart Failure Trial. The relation between baseline BNP and NE and all-cause mortality and first morbid event (M&M) was analyzed in subgroups, with values above and below the median, and by quartiles. The change and percent change from baseline to 4 and 12 months in BNP and NE were also analyzed by quartiles for subsequent M&M. Risk ratios for M&M were calculated using a Cox proportional hazard model. Risk ratio of M&M for patients with baseline BNP or NE above the median was significantly higher than that for patients with values below the median. Baseline BNP and NE in quartiles also showed a quartile-dependent increase in M&M. BNP had a stronger association with M&M than NE. Patients with the greatest percent decrease in BNP and NE from baseline to 4 and 12 months had the lowest whereas patients with greatest percent increase in BNP and NE had the highest M&M.

Conclusions—

Not only are plasma BNP and NE important predictors of heart failure M&M, but changes in these neurohormones over time are associated with corresponding changes in M&M. These data further reinforce their role as significant surrogate markers in HF and underscore the importance of including their measurement in HF trials.
Eliminating Atherogenesis in Mice by Switching Off Hepatic Lipoprotein Secretion
Authors: Lieu Hsiao D. , Withycombe Shannon K. , Walker Quinn , Rong James X. , Walzem Rosemary L. , Wong Jinny S. , Hamilton Robert L. , Fisher Edward A. , Young Stephen G.
Published: March 2003

Background—

LDL receptor–deficient “apolipoprotein (apo)-B100–only” mice (
Ldlr
−/−
Apob
100/100
have elevated LDL cholesterol levels on a chow diet and develop severe aortic atherosclerosis. We hypothesized that both the hypercholesterolemia and the susceptibility to atherosclerosis could be eliminated by switching off hepatic lipoprotein production.

Methods and Results—

We bred
Ldlr
−/−
Apob
100/100
mice that were homozygous for a conditional allele for
Mttp
(the gene for microsomal triglyceride transfer protein) and the inducible
Mx1
-
Cre
transgene. In these animals, which we called “Reversa mice,” the hypercholesterolemia could be reversed, without modifying the diet or initiating a hypolipidemic drug, by the transient induction of
Cre
expression in the liver. After
Cre
induction, hepatic
Mttp
expression was virtually eliminated (as judged by quantitative real-time PCR), hepatic lipoprotein secretion was abolished (as judged by electron microscopy), and LDLs were virtually eliminated from the plasma. Intestinal lipoprotein production was unaffected. In mice fed a chow diet,
Cre
induction reduced plasma cholesterol levels from 233.9±46.0 to 37.2±6.5 mg/dL. In mice fed a high-fat diet, cholesterol levels fell from 525.7±32.2 to 100.6±14.3 mg/dL. The elimination of hepatic lipoprotein production completely prevented both the development of atherosclerosis and the changes in gene expression that accompany atherogenesis.

Conclusions—

We developed mice in which hypercholesterolemia can be reversed with a genetic switch. These mice will be useful for understanding gene-expression changes that accompany the reversal of hypercholesterolemia and atherosclerosis.
Stromal Cell–Derived Factor-1 Effects on Ex Vivo Expanded Endothelial Progenitor Cell Recruitment for Ischemic Neovascularization
Authors: Yamaguchi Jun-ichi , Kusano Kengo Fukushima , Masuo Osamu , Kawamoto Atsuhiko , Silver Marcy , Murasawa Satoshi , Bosch-Marce Marta , Masuda Haruchika , Losordo Douglas W. , Isner Jeffrey M. , Asahara Takayuki
Published: March 2003

Background—

Stromal cell–derived factor-1 (SDF-1) is a chemokine considered to play an important role in the trafficking of hematopoietic stem cells. Given the close relationship between hematopoietic stem cells and endothelial progenitor cells (EPCs), we investigated the effect of SDF-1 on EPC-mediated vasculogenesis.

Methods and Results—

Flow cytometric analysis demonstrated expression of CXCR4, the receptor of SDF-1, by 66±3% of EPCs after 7 days in culture. In vitro modified Boyden chamber assay showed a dose-dependent EPC migration toward SDF-1 (control versus 10 ng/mL SDF-1 versus 100 ng/mL SDF-1, 24±2 versus 71±3 versus 140±6 cells/mm
2
;
P
<0.0001). SDF-1 attenuated EPC apoptosis (control versus SDF-1, 27±1 versus 7±1%;
P
<0.0001). To investigate the effect of SDF-1 in vivo, we locally injected SDF-1 into athymic ischemic hindlimb muscle of nude mice combined with human EPC transplantation to determine whether SDF-1 augmented EPC-induced vasculogenesis. Fluorescence microscopic examination disclosed increased local accumulation of fluorescence-labeled EPCs in ischemic muscle in the SDF-1 treatment group (control versus SDF-1=241±25 versus 445±24 cells/mm
2
,
P
<0.0001). At day 28 after treatment, ischemic tissue perfusion was improved in the SDF-1 group and capillary density was also increased. (control versus SDF-1, 355±26 versus 551±30 cells/mm
2
;
P
<0.0001).

Conclusion—

These findings indicate that locally delivered SDF-1 augments vasculogenesis and subsequently contributes to ischemic neovascularization in vivo by augmenting EPC recruitment in ischemic tissues.
Diferencias cuantitativas y cualitativas entre mujeres y varones medidas a través de los usos del tiempo
Authors: Álvaro Mariano
Published: March 2003

En este artículo, se estudia si las diferencias entre géneros en los Usos del tiempo ponen en evidencia ciertas diferencias en Igualdad social, Calidad de vida, Autonomía personal, Trabajo doméstico y Productividad económica. Para medir las diferencias en cada una de estas dimensiones, se ha utilizado un indicador, en el que, a partir de ciertos planteamientos teóricos, se ha atribuido un peso determinado a las diferentes variables de Uso del tiempo.

Además de los resultados obtenidos con los indicadores utilizados, el artículo incluye una revisión bibliográfica, sobre los indicadores sociales, en general, y un análisis de las diferencias entre géneros en las variables de Usos del tiempo utilizadas.
Hydrolytically activated etoposide prodrugs inhibit MDR-1 function and eradicate established MDR-1 multidrug-resistant T-cell leukemia
Authors: Schroeder Ulrike , Bernt Kathrin M. , Lange Björn , Wenkel Jens , Jikai Jiang , Shabat Doron , Amir Roey , Huebener Nicole , Niethammer Andreas G. , Hagemeier Christian , Wiebusch Lüder , Gaedicke Gerhard , Wrasidlo Wolfgang , Reisfeld Ralph A. , Lode Holger N.
Published: March 2003

Effective therapy of high-risk leukemia with established cytotoxic drugs may be limited by poor antitumor efficacy, systemic toxicity, and the induction of drug resistance. Here, we provide the first evidence that hydrolytically activated prodrugs may overcome these problems. For this purpose, VP16 was functionally blocked by hydrolytically cleavable carbonate linkers with unique characteristics to generate 2 novel prodrugs of VP16. First, we established a more than 3-log higher efficacy of the 2 prodrugs compared with VP16 on a panel of naturally drug-resistant tumor cell lines. Second, the prodrugs did overcome VP16-induced multidrug resistance-1 gene (MDR-1)—mediated multidrug resistance in vitro in a newly established VP16-resistant T-cell leukemia cell line MOVP-3 by functionally blocking MDR-1—mediated efflux. Third, in vivo studies showed a maximum tolerated dose of ProVP16-II (> 45mg/kg), which was at least 3-fold higher than that of VP16 (15 mg/kg). Finally, tests of ProVP16-II in a multidrug-resistant xenograft model of T-cell leukemia expressing MDR-1 indicated that only the mice treated with this prodrug revealed a complete and long-lasting regression of established, drug-resistant leukemia. In summary, the hydrolytically activated etoposide prodrugs proved effective against multidrug-resistant T-cell leukemia in vitro and in vivo and provide proof of concept for a highly promising new strategy for the treatment of MDR-1 drug-resistant malignancies. (Blood. 2003;102:246-253)
Functional p85α gene is required for normal murine fetal erythropoiesis
Authors: Huddleston Hannah , Tan Bailin , Yang Feng-Chun , White Hilary , Wenning Mary Jo , Orazi Attilio , Yoder Mervin C. , Kapur Reuben , Ingram David A.
Published: March 2003

In vitro studies suggest that activation of class IA phosphatidylinositol 3 (PI-3) kinase is necessary for normal erythroid cell development. However, when class IA PI-3 kinase–deficient mice were generated by a targeted deletion of the p85α regulatory subunit, fetal erythropoiesis was reportedly unaffected. Given the discrepancies between these studies, we performed a more detailed in vivo analysis of class IA PI-3 kinase–deficient embryos. Day-14.5 p85α-/- embryos are pale with a marked reduction of mature erythrocytes in their peripheral blood. Further, the absolute number and frequency of both early (erythroid burst-forming unit [BFU-E]) and late erythroid progenitors (erythroid colony-forming unit [CFU-E]) are reduced in p85α-/- fetal livers compared with wild-type controls, which is associated with reduced proliferation. Taken together, these data establish an important role for p85α and class IA PI-3 kinase in regulating the development of both early and late erythroid progenitors in fetal liver. (Blood. 2003;102:142-145)
Clinical-cytogenetic associations in 306 patients with therapy-related myelodysplasia and myeloid leukemia: the University of Chicago series
Authors: Smith Sonali M. , Le Beau Michelle M. , Huo Dezheng , Karrison Theodore , Sobecks Ronald M. , Anastasi John , Vardiman James W. , Rowley Janet D. , Larson Richard A.
Published: March 2003

Therapy-related myelodysplasia and myeloid leukemia (t-MDS/t-AML) is a distinctive clinical syndrome occurring after exposure to chemotherapy (CT) or radiotherapy (RT). We report findings on 306 consecutive patients referred to our institution with morphologic review and cytogenetic analyses. Since 1972, 141 males and 165 females with a median age of 51 years (range, 3-83 years) at primary diagnosis and 58 years (range, 6-86 years) at secondary diagnosis were analyzed. Patients had been administered various cytotoxic agents, including alkylating agents (240 patients, 78%) and topoisomerase 2 inhibitors (115 patients, 39%). One hundred twenty-one (40%) had undergone CT alone, 43 (14%) had undergone RT alone, and 139 (45%) had undergone both modalities. At diagnosis of t-MDS/t-AML, 282 (92%) had clonal abnormalities involving chromosome 5 (n = 63), chromosome 7 (n = 85), chromosomes 5 and 7 (n = 66), recurring balanced rearrangements (n = 31), other clonal abnormalities (n = 39), or normal karyotype (n = 24). Abnormalities of chromosome 5, 7, or both accounted for 76% of all cases with an abnormal karyotype. Seventeen patients acquired t-MDS/t-AML after autologous stem cell transplantation, but no unique pattern of cytogenetic abnormalities was observed. Shorter latency was observed for patients with balanced rearrangements (median, 28 vs 67 months; P < .0001). Patients with acute leukemia were more likely to have balanced rearrangement than those with myelodysplasia (28% vs 4%; P < .0001). Median survival time after diagnosis of t-MDS/t-AML was 8 months; survival at 5 years was less than 10%. These data confirm and extend previous associations between clinical, morphologic, and cytogenetic findings in t-MDS/t-AML. (Blood. 2003;102:43-52)
From medical to health geography: novelty, place and theory after a decade of change
Authors: Kearns Robin , Moon Graham
Published: March 2003

In this paper, we reflect on the positioning of health geography within the wider academic landscapes of geography and health-related research. Drawing on examples from a number of countries, we consider the extent to which a ‘new geography of health’ has emerged in recent years. We structure our discussion around the themes of place, theoretical engagement and critical relevancy. Changes within the subdiscipline are placed in the context of a central question: what is new about the new geography of health?
Geographies of the agenda: public policy, the discipline and its (re)‘turns’
Authors: Dorling Danny , Shaw Mary
Published: March 2003

In the 1980s and 1990s, poverty and inequality in Britain increased, yet the discipline of (human) geography was apparently disinterested. This paper poses the question as to why part of the discipline turned its back on public policy and particularly issues of poverty and inequality. The aim of the paper is to encourage students and advocates of geography to think a little about what they are involved in (and to think about the role of academia more generally). Recent publications in a number of geography journals have revealed much angst among prominent geographers concerning the state of human geography and, in particular, its links to contemporary policy debate. However, while geographers discuss the debate, we argue that they are not a significant part of it. We take a critical turn and look at the debate that two geographers – Ron Martin and Doreen Massey – have raised within the light of wider debates on public policy, politics, quantification, academia and the policy agenda. We conclude that for many reasons there is unlikely to be a large shift towards policy-orientated research within human geography.
Deliver us from evil? Prospects for living ethically and acting politically in human geography
Authors: Cloke Paul
Published: March 2003

This paper addresses the dilemma of how easy it is to talk and write about human geographies of ethics and justice compared to the difficulties of living out those geographies in our everyday life practices. If radical ideas and radical practices are to go hand in hand, we need to address the apparent inability to retain a critical political edge in human geography. The paper comments on new readings of moral and ethical geographies, noting Marc Augé's distinction between a sense of the other and a sense for the other, and arguing that any goal in human geography for developing an emotional, connected and committed sense for the other may necessitate a prompting of the moral imagination which includes political/ethical/spiritual constellations of issues such as charity, agape and evil. Drawing on the work of Hannah Arendt and Melissa Orlie, the paper emphasizes imaginations of power that recognize ‘evil’, the crisis of the citizen-subject, and the recovery of political enthusiasms for ‘invisible powers’. It envisions a human geography in which living ethically and acting politically can be essentially intertwined with a sense for the other in a sensitive, committed and active approach to the subject. This entails both a continuing engagement in collective political action against ordered evil, and taking responsibility for what we have been made to be and for who we are becoming.
Modern and ancient periglacial river types
Authors: Vandenberghe Jef , Woo Ming-ko
Published: March 2003

Climate has been proposed conventionally as the primary factor that determines periglacial river activity (aggradation) and pattern (braided). This concept does not explain the rich diversity in river patterns and morphological processes in both the present and past periglacial environments: besides braided rivers and sandur, meandering, anabranching, transitional and deltaic rivers also occur. A first attempt is made to combine past and present periglacial river types with regard to their morphology, processes and environments. The processes that control river energy and morphology are discussed especially for periglacial conditions. This approach permits an assessment of the responses of periglacial rivers to climatic conditions and the modulation of the responses due to changes in the basin properties. Examples drawn from palaeo- and present-day periglacial rivers and environments demonstrate that there is no unique type of periglacial river but rather an azonal fluvial system with a number of periglacial variants.
Sandy aeolian deposits and environments and their relation to climate during the Last Glacial Maximum and Lateglacial in northwest and central Europe
Authors: (Kees) Kasse Cornelis
Published: March 2003

Periglacial aeolian sand sheets and dunes of the last glacial cover extensive areas of northwest and central Europe. Four sedimentary facies have been described that could be related to fluvio-aeolian and cryogenic processes, moisture content of the depositional surface and surface morphology. Factors that favoured sand-sheet and low-dune formation were the abundance of unconsolidated sediments, absence of topographic barriers, sparseness of vegetation cover and the high ratio of wind energy to sand availability. Three phases of prominent aeolian sand deposition have been distinguished from the Last Glacial Maximum to the beginning of the Holocene. Phase I (c. 28-18 ka cal B.P.) with predominant fluvio-aeolian deposition was related to permafrost conditions of the Last Glacial Maximum. Phase II (c. 18-14 cal B.P.) represents the major period of sand-sheet or coversand formation at the waning stage of the last glacial (Late Pleniglacial and early Lateglacial). Phase III (c. 13-10 cal B.P.) with more localized deposition occurred in the later part of the Younger Dryas and early Holocene. It is stressed that the aeolian phases do not strictly coincide with glacial or stadial conditions. Climatic aridity, limited vegetation cover and delayed responses of the aeolian environment to climate change determine the timing of the aeolian phases.
Nivation and cryoplanation: the case for scrutiny and integration
Authors: Thorn Colin E. , Hall Kevin
Published: March 2003

Nivation and cryoplanation are deeply entrenched and widely invoked morphogenetic concepts within periglacial geomorphology. However, given their complexity and purported significance in landform development, neither has received the scientific scrutiny merited. Nivation is generally associated with the weathering and mass movement processes stemming from late-lying seasonal snow and the ensuing landforms. As a process suite it invokes mechanisms such as freeze-thaw weathering and solifluction. Cryoplanation also invokes a process suite, but one that also embraces nivation. Research in the last two or three decades has begun to provide a much sharper definition of nivation, but the available information is still inadequate for a central mechanism in periglacial landscapes. Cryoplanation is used to explain some benches, terraces and pediments that appear to be widespread in some periglacial environments: however, substantive field research on the mechanisms involved is all but absent. A case is presented for viewing nivation and cryoplanation as a single process spectrum much in need of state-of-the-art research.
Recent research on the nature, origin and climatic relations of blocky and stratified slope deposits
Authors: van Steijn Henk , Boelhouwers Jan , Harris Stuart , Hétu Bernard
Published: March 2003

A selection of subaerial slope processes is discussed together with the morphological and sedimentological traces that are left by the processes. Emphasis is on mass transfers related to (coarse) blocky slopes and to scree accumulations, either on steep or on gentle slopes. New developments in the interpretation of more or less clearly stratified slope deposits are discussed in the light of the findings of research focusing on present-day process-form (process-material) relationships. The question of the climatic (and, more specifically, the periglacial) significance of the different processes and their morpho-sedimentary expression is a returning theme in this paper. It is concluded that many deposits are formed by azonal processes, although their activity (in terms of magnitude-frequency combinations) is often relatively high under periglacial conditions. Some of the deposits point to (cold-climate) extreme events. This especially is the case for frost-coated clast flows, aeolian transport of large platy clasts, and to a lesser extent debris flows.
Weathering in cold regions: some thoughts and perspectives
Authors: Hall Kevin , Thorn Colin E. , Matsuoka Norikazu , Prick Angelique
Published: March 2003

Weathering in cold regions has primarily focused on the notion of ‘cold’, such that process and landform theory have generally used this both as the developmental criterion and as the outcome of palaeoenvironmental reconstructions based on landforms or sediments. As a result of this approach, the process focus in terms of weathering has been that mechanical processes predominate, with freeze-thaw weathering as the prime agent, and that chemical processes are temperature-inhibited, often to the point of nonoccurrence. Here a reconsideration of the whole conceptual framework of weathering in cold environments is undertaken. It is shown that, contrary to popular presentations, weathering, including chemical weathering, is not temperature-limited but rather is limited by moisture availability. Indeed, summer, and oft-times even winter, rock temperatures are more than adequate to support mechanical and chemical weathering if water is present. Where water is available it is clearly shown that chemical weathering can be a major component of the weathering regime. The argument is made that there is no zonality to cold environment weathering as none of the processes or process associations are unique to cold regions; indeed, many cold regions show similar weathering assemblages to those in hot arid regions. Process-form relationships are also questioned. The assumption of angularity with weathering in cold regions is questioned, all the more so as hot arid studies identify exactly the same angularity of debris form. Further, that all forms have to be angular is shown by field examples to be no more than an artefact of original unquestioning and oft-repeated assumptions, now over a century or more old. The argument is made that there is a strong need for the reconsideration of the nature of weathering in cold environments, that current theory should be questioned and challenged, and field observation undertaken within this revised frame of reference.
Palsas, lithalsas and remnants of these periglacial mounds. A progress report
Authors: Pissart A.
Published: March 2003

There is no general agreement about the meaning of the word ‘palsa’. Usage and recent suggested definitions indicate that the word is chiefly used for cryogenic mounds covered by peat that were formed by an accumulation of segregation ice in the discontinuous permafrost zone. Lithalsas are similar mounds, but without any peat cover. The thickness of aggradation ice on the top of lithalsas can be considerable. Use of development and decay palsas as indicators of climatic change is difficult. The climatic conditions in which lithalsas form are much more restricted than those for palsas and, as a consequence, regions where lithalsas exist are rather rare. After melting, lithalsas leave ramparted depressions; the mass movements on the peaty slopes of palsas are less propitious to the formation of ramparts. Some of the pingo remnants described in western Europe are, more accurately, lithalsa traces.
Permafrost mapping: a review
Authors: Heginbottom J. Alan
Published: March 2003

Permafrost maps have developed over the last century from small line drawings showing the outer limits of the areas within which perennially frozen ground was known or supposed to exist, to large scale, multi-sheet, multi-faceted, complex earth-science documents. These show, in considerable detail, the estimated distribution of frozen ground, in terms of its spatial continuity, thickness, ground temperature and ground ice content. Other related geo-environmental information is commonly included along with the permafrost attributes. The key geocryological issues in permafrost mapping comprise definition, purpose, classification, data acquisition, and data storage and processing. The principal cartographic issues relate to map design, legend development and map production. The recent development of geographic information software (GIS) suitable for use on a desk-top computer allows the geocryologist to undertake many map compilation and production tasks directly. GIS software also allows the map compiler or map user to manipulate the data, layer by layer, and so create specialized maps for specific purposes. Computer storage and processing of permafrost data allows large volumes of data to be handled and, when combined with modelling techniques, allows these large volumes of data to be used in the compilation of maps. Integration of modelling techniques with GIS is a powerful tool for assessing the response of permafrost to a changing climate. Other research directions are noted.
Mapping of mountain permafrost using geophysical methods
Authors: Vonder Mühll Daniel , Hauck Christian , Gubler Hansueli
Published: March 2003

Permafrost distribution in nonpolar mountain areas is strongly influenced by topo-graphical effects. Conditions therefore change within short distances and consequently the permafrost pattern is often very complex. Warm permafrost with temperatures between -2°C and 0°C is sensitive in terms of slope failures. It is also crucial to determine the lower permafrost boundary by geophysical means in order to calibrate models. Various geophysical methods have been applied to the mapping of mountain permafrost, including bottom temperature of the snow cover (BTS), refraction seismics, DC resistivity, ground penetrating radar (GPR), electromagnetic induction and radiometry.

This paper gives an overview of investigations to map mountain permafrost distribution showing the potential of the modern use of geophysical methods. The two-dimensional DC resistivity tomography makes it possible to get an impression of internal structures. Electromagnetic induction methods showed good results, in particular the EM-31 for determining the permafrost distribution and the PROTEM to assess the overall permafrost thickness. Using passive microwave (11.4 GHz), the BTS, which is used as an indicator for the presence of permafrost, was measured. After ground surveys, an airborne test measurement from a helicopter was made. Traditional BTS measurements agreed very well with the BTS determined by radiometry.
Exact unconditional tests for a 2 × 2 matched-pairs design
Authors: Berger R L , Sidik K
Published: March 2003

The problem of comparing two proportions in a 2 × 2 matched-pairs design with binary responses is considered. We consider one-sided null and alternative hypotheses. The problem has two nuisance parameters. Using the monotonicity of the multinomial distribution, four exact unconditional tests based on p-values are proposed by reducing the dimension of the nuisance parameter space from two to one in computation. The size and power of the four exact tests and two other tests, the exact conditional binomial test and the asymptotic McNemar’s test, are considered. It is shown that the tests based on the confidence interval p-value are more powerful than the tests based on the standard p-value. In addition, it is found that the exact conditional binomial test is conservative and not powerful for testing the hypothesis. Moreover, the asymptotic McNemar’s test is shown to have incorrect size; that is, its size is larger than the nominal level of the test. Overall, the test based on McNemar’s statistic and the confidence interval p-value is found to be the most powerful test with the correct size among the tests in this comparison.
Monte Carlo conditional inference for log-linear and logistic models: a survey of current methodology
Authors: Caffo B S , Booth J G
Published: March 2003

Nuisance parameters are parameters that are not of immediate interest to the experimenter. For log-linear and logistic models the null distribution of (most) statistics of interest depends on such parameters. Traditionally, nuisance parameters were eliminated by performing inference with respect to the chi-squared limiting distribution of common test statistics. An alternative solution is to eliminate the nuisance parameters by conditioning on their minimal sufficient statistics. The support of the resulting conditional distribution is often intractable, making null probability calculations challenging. An often feasible way to avoid complete enumeration of this support is to approximate conditional probabilities using Monte Carlo methods. In this article we survey recent developments in Monte Carlo conditional analysis for log-linear and logistic models focusing on the algorithms proposed by Booth and Butler,1Diaconis and Sturmfels,2Smith et al.,3and Mehta et al.4We illustrate these algorithms with simple motivating examples.
Latent mixed Markov modelling of smoking transitions using Monte Carlo bootstrapping
Authors: Mannan Haider R , Koval John J
Published: March 2003

It has been established that measures and reports of smoking behaviours are subject to substantial measurement errors. Thus, the manifest Markov model which does not consider measurement error in observed responses may not be adequate to mathematically model changes in adolescent smoking behaviour over time. For this purpose we fit several Mixed Markov Latent Class (MMLC) models using data sets from two longitudinal panel studies—the third Waterloo Smoking Prevention study and the UWO smoking study, which have varying numbers of measurements on adolescent smoking behaviour. However, the conventional statistics used for testing goodness of fit of these models do not follow the theoretical chi-square distribution when there is data sparsity. The two data sets analysed had varying degrees of sparsity. This problem can be solved by estimating the proper distribution of fit measures using Monte Carlo bootstrap simulation. In this study, we showed that incorporating response uncertainty in smoking behaviour significantly improved the fit of a single Markov chain model. However, the single chain latent Markov model did not adequately fit the two data sets indicating that the smoking process was heterogeneous with regard to latent Markov chains. It was found that a higher percentage of students (except for never smokers) changed their smoking behaviours over time at the manifest level compared to the latent or true level. The smoking process generally accelerated with time. The students had a tendency to underreport their smoking behaviours while response uncertainty was estimated to be considerably less for the Waterloo smoking study which adopted the ‘bogus pipeline’ method for reducing measurement error while the UWO study did not. For the two-chain latent mixed Markov models, incorporating a ‘stayer’ chain to an unrestricted Markov chain led to a significant improvement in model fit for the UWO study only. For both data sets, the assumption for the existence of an independence chain did not lead to significant improvement in model fit. The unrestricted two-chain latent mixed Markov model led to a significant improvement of model fit compared to a simple latent Markov model, but this model was overparameterized when the latent transition probabilities and=or response probabilities were assumed nonstationary. For the other models, the manifest=latent transition probabilities and response probabilities (for the four-wave Waterloo study only) were tested to be nonstationary for both data sets.
Necrotizing fasciitis following rituximab therapy
Authors: Krieger Jim A , Merin Jan M , Rabinowitz Ian
Published: March 2003

Rituximab has considerably modified thetherapeutic strategy for B-cell lymphoproliferative malignancies, most notably non-Hodgkin’s lymphoma (NHL). Rituximab, alone or in combination with chemo-therapy, is being used to treat NHL with limited toxicity. We report two cases, one fatal, of necrotizing fasciitis following the use of rituximab in patients with NHL. No obvious predisposing factors were noted in either case. Practitioners need to beaware of this rare side effect and take prompt and aggressive action at the first onset of symptoms.
Updating a survey for medication error prevention
Authors: Grindrod Kelly Anne , Chambers Carole R , Hicks Jolene
Published: March 2003

Objective. Literature review and subsequent gap analysis of the current Alberta Cancer Board (ACB) Oncology Medication Error Prevention Status Survey and the incorporation of new information to aid in the development of a stronger medication error prevention system.

Design. Gap analysis based on a literature review was performed on the current ACB survey via a literature search of EMBASE, Medline, and the Cochrane Database of Systematic Reviews. The completed survey was sent to 17 ACB sites for feedback.

Setting. The ACB in the Canadian province of Alberta, which includes 2 public tertiary centers and 15 associated community satellite sites based around the province in existing hospitals.

Main outcome measures. Gaps in the current medication error prevention survey requiring improvement as compared to current literature, with emphasis on pharmacy.

Results. All sections required additional information and two new sections were created to reduce the gaps in organizational commitment and environmental concerns. Of the 17 ACB sites, 13 sites responded to the survey and 11 responded to the questionnaire. Out of a possible 154 questions, 64 questions had at least one site disagree and 20 questions had more than one site disagree.

Conclusion. Through a literature review and gap analysis, the current ACB Oncology Medication Error Prevention Status Survey was improved. Responses to changes have not only demonstrated the need for a survey of this kind, but also the need for periodic updates of the information in the survey.
Physician order entry: a mixed blessing to pharmacy?
Authors: Beer Jamie , Dobish Roxanne , Chambers Carole
Published: March 2003

Objective. The Alberta Cancer Board (ACB) Pharmacy conducted a timing study to determine how electronic prescription ordering impacts the workload in pharmacy in comparison to the current paper system. The objective was to compare the mean time required to review orders generated by an electronic physician order entry system to the existing paper method, and to determine whether such an implementation would decrease pharmacist intervention rates.

Methods. Self-reporting and measurement by stopwatch timing were used to record the timing data on the prescription order review process on all outpatient parenteral chemotherapy orders for adults handled within the ACB’s two main tertiary centres for the month of June. The primary endpoint measured was mean pharmacist order review time for manual and electronic orders. The secondary endpoint measured was pharmacist intervention rate for manual and electronic orders.

Results. Among all 836 chemotherapy orders reviewed, the mean pharmacist order review time was increased by 5.15 min with the implementation of an electronic order entry system. A total of 62 pharmacist interventions were recorded in the study. The pharmacist intervention rate was 7.14% for the electronic orders and 7.47% for the manual paper orders.

Conclusions. The study showed that the implementation of an electronic physician order entry system has significant impacts on pharmacy workload without providing significant reductions in pharmacist intervention rates.
Cyclophosphamide-induced nasopharyngeal discomfort (wasabi nose): a report of two cases
Authors: Lo Kelly S C , Aulakh Amneet K , Gingerich Keith S , Taylor Suzanne C Malfair
Published: March 2003

Transient nasopharyngeal discomfort induced by cyclophosphamide infusion has been described in a few previous case reports. There is a theory that these adverse effects may have a cholinergic mechanism. Several measures have been reported to be successful in relieving these symptoms in some patients. This is a report of two cases in the same institution. In one case, unlike previously reported cases, the nasopharyngeal pain had a delayed onset and was extremely severe and persistent despite the usual interventions. In another case, the symptom was described as ‘wasabi nose’ (the burning, painful feeling that results from eating sushi with wasabi), and appeared to have been relieved by nebulized ipratropium, which has not been previously reported.
Kinematics and dynamics of a general-purpose, parallel, compliant micromanipulator
Authors: Liu P A , Li Q
Published: March 2003

Kinematic and dynamic modelling of a three-degrees-of-freedom (3DOF) planar parallel manipulator is presented in this paper. An equilateral triangle forms the output stage of the mechanism, and three driving structures, connected via three links, provide stroke magnification to the output stage. Aiming at achieving micromotions, this manipulator is developed using compliant material. In order to reduce assembly errors, a monolithic structure is adopted in this design. Hence, the joints in this mechanism are all flexural hinges. Since the masses and moments of inertia can be neglected in this lightweight micromanipulator, and the joint resistances are greatly increased owing to the flexure of the joints, new problems arise in the design and modelling of such a mechanism. The results presented in this paper will provide useful information for the design and applications of parallel, compliant micromanipulators.
Multi-body modelling of timing belt dynamics
Authors: Callegari M , Cannella F , Ferri G
Published: March 2003

Although timing belt drives have recently been increasingly used in mechanical design, their behaviour is still considered to a large extent to be unpredictable, especially under varying operative conditions. The acoustic emission of the transmissions, above all, has been thoroughly investigated in past years, but noise still represents an unresolved problem for many applications and a concern for belt designers; therefore, the availability of good predictive models would be very useful for both design and application phases. The present work describes a multi-body numerical model that has been developed for the characterization of the dynamic behaviour of timing belt transmissions, with the final goal of assessing the acoustic radiation of a given design. Modelling and simulation have been performed by means of commercial software packages, but more additional programming was required to obtain dynamic models capable of simulating the complex behaviour of toothed belt transmissions. Several experimental tests have been performed to identify the many parameters that influence system dynamics and to validate the resulting computer aided engineering (CAE) model.
Occupational asthma symptoms and respiratory function among aerial pesticide applicators
Authors: Jones Stacie M. , Burks A. Wesley , Spencer Horace J. , Lensing Shelly , Roberson Paula K. , Gandy Jay , Helm Rick M.
Published: March 2003

Background

Pesticide exposure has been suggested as one causal factor for the rise in asthma prevalence. The goal of this investigation was to determine the effect of pesticide exposure on respiratory symptoms and lung function in workers with occupational exposure to pesticides.

Methods

A prospective, case‐controlled study was conducted among pesticide aviators (AV) and community controls (Con). In Phase I, subjects completed an asthma survey and baseline spirometry. In Phase II, subjects reported symptoms, lung function monitoring, and pesticide exposure during two, 14‐day periods.

Results

Phase I—Self‐reported asthma and symptoms were similar among AV (n = 135) and Con (n = 118) with 4–6% prevalence reported but with higher rates among smokers. Baseline lung function was similar; although, a higher proportion of AV had forced expiratory volume in one second (FEV1) <80% predicted (8% vs. 2%, P = 0.02). Phase II—Self‐reported symptoms were similar with 80% of AV (n = 50) and 73% of Con (n = 49) reporting no symptoms. Only 4% of AV and 6% of controls reported increased symptoms from baseline to spray season. Serial lung function did not differ between group and mean diurnal variation in peak expiratory flow improved in both groups between sampling times (AV 18% vs. 14%; Con 19% vs. 16%, P < 0.001).

Conclusions

This study suggests that among workers with occupational pesticide exposure, asthma symptoms and lung function are similar to those of controls with only community‐based exposure. Am. J. Ind. Med. 43:407–417, 2003. © 2003 Wiley‐Liss, Inc.
Synthesis of novel amphiphilic pyridinylboronic acids
Authors: Matondo Hubert , Baboulène Michel , Rico‐Lattes Isabelle
Published: March 2003

Novel 3‐alkoxy‐2‐pyridinylboronic acids bearing, in their 3‐position, linear alkoxy or perfluoroalkoxy chains with n carbon atoms (n = 6, 8, 10, 12 and 18) 2a–2g are synthesized from 2‐bromo‐3‐pyridinol, which is the common starting product. Our alternative procedure for the synthesis of 3‐alkoxy‐2‐bromopyridine in a phase‐transfer catalysis system is to carry out the reaction in a solid–liquid medium in the presence of a quaternary ammonium salt under microwave irradiation. General and versatile synthetic methods have been developed for preparation of a large variety of new 2‐pyridinylboronic acids bearing two alkylated or perfluoroalkylated side chains with an ether junction in the 3‐position. Copyright © 2003 John Wiley & Sons, Ltd.
The competency of criminal defendants to refuse, for delusional reasons, a viable insanity defense recommended by counsel
Authors: Litwack Thomas R.
Published: March 2003

This article addresses the issues of whether mentally ill defendants charged with serious crimes who refuse to plead a viable and counsel‐recommended insanity defense for delusional reasons (but who are otherwise competent to stand trial) should be considered to be competent, or incompetent, to stand trial; whether such defendants should be allowed to represent themselves with a delusional defense; and whether an insanity defense may properly be imposed upon such defendants. Based on an analysis of relevant Supreme Court decisions and other relevant cases, it is concluded that such defendants should not be allowed to go forward with a delusional defense (at least until reasonable efforts to treat the defendants' delusions are made). It is also argued, however, that unless an insanity defense would be viable (as well as recommended by counsel) delusional defendants who are otherwise competent to stand trial should be permitted to go forward, and represent themselves, with the defense of their choosing. Copyright © 2003 John Wiley & Sons, Ltd.