bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlocal kinetic theory of Alfvén waves on dipolar field lines
Authors: Lysak Robert L. , Song Yan
Published: August 2003

Recent observations have indicated that in addition to the quasi‐static acceleration of electrons in inverted V structures, auroral electrons frequently have a spectrum that is broad in energy and confined to parallel pitch angles, indicative of acceleration in low‐frequency waves. Test particle models have indicated that these electrons may be accelerated by the parallel electric fields in kinetic Alfvén waves. However, such models are not self‐consistent, in that the wave structure is not influenced by the accelerated particles. A nonlocal kinetic theory of electrons along auroral field lines is necessary to provide this self‐consistency. Results from such a model based on electron motions on dipole field lines are presented. For a typical Alfvén speed profile, kinetic effects lead to significant energy dissipation when the electron temperature exceeds ∼100 eV. The dissipation generally occurs near the peak of the Alfvén speed profile. This dissipation generally increases with increasing temperature and decreasing perpendicular wavelength up to ∼1 keV and 10 km, respectively. At larger temperatures and smaller perpendicular wavelengths the dissipation begins to decrease and the ionospheric Joule dissipation goes to zero, indicating that the wave is reflected from the dissipation region. Dissipation in the 0.1–1.0 Hz band is structured by the modes of the ionospheric Alfvén resonator.
Seasonal renewal of the California Current: The spring transition off California
Authors: Lynn Ronald J. , Bograd Steven J. , Chereskin Teresa K. , Huyer Adriana
Published: August 2003

A pair of high‐resolution oceanographic surveys in March and April 1995 revealed a large and rapid transition from late winter to spring conditions in the coastal zone off central and southern California. These data are unique in capturing the detailed three‐dimensional physical structure of and biological response to the spring transition in the southern California Current System (CCS). Changes associated with the transition included a strong tilting of isopycnals, which lifted by up to 60 m near the coast and dropped 20–40 m offshore, a subsequent increase in cross‐shore density gradients, the development of a strong nearshore equatorward jet, and an increase in net equatorward transport from the shelf break out to 300 km offshore. The most dramatic physical changes were confined to the shoreward 150 km and extended at least to the depth of the core of the California Undercurrent (∼300 m). In response to these physical changes, there was an apparent strong increase in primary productivity, as indicated by changes in nearshore vertically integrated fluorescence and beam attenuation coefficient. Atmospheric and oceanic conditions in the CCS were near seasonal norms in the winter and spring of 1995, implying that a transition of the magnitude and rapidity observed here may be an annual event. Furthermore, the development of the coastal upwelling jet was independent of the winter manifestation of the main core of the California Current, which was maintained well off shore. This suggests that the California Current is regenerated seasonally through the development and offshore evolution of the coastal upwelling jet. It is not known whether the new jet joins and strengthens or replaces the offshore core of the previous winter.
Chemical properties and outflow patterns of anthropogenic and dust particles on Rishiri Island during the Asian Pacific Regional Aerosol Characterization Experiment (ACE‐Asia)
Authors: Matsumoto Kiyoshi , Uyama Yukiko , Hayano Teruaki , Tanimoto Hiroshi , Uno Itsushi , Uematsu Mitsuo
Published: August 2003

Investigations of chemical properties and transport mechanisms of continental aerosols are necessary for estimating their influences on global radiative budget and on the global material cycle. Intensive measurements of atmospheric aerosols and the associated species on Rishiri Island, near the northern tip of Japan, were conducted from March to May 2001, in order to understand the chemical properties, source regions, transport pathways, and transport patterns of anthropogenic and mineral aerosols over the east Asian Pacific Rim region during the spring. Mean concentrations of nss‐SO42−, NO3−, NH4+, nss‐Ca2+ in aerosols were 2.48, 0.64, 0.72, and 0.17 μg m−3, respectively. Elemental carbon and organic carbon in fine particles (d < 2.5 μm) yielded mean concentrations of 0.25 and 0.80 μg m−3, respectively. The concentrations of these species frequently increased to higher values because of outbreaks of continental polluted air masses, whereas under background conditions, they decreased to lower values similar to those observed over the remote ocean. Our results demonstrate that nss‐SO42− and NH4+ coexist in fine particles, that NO3− and nss‐Ca2+ coexist in coarse particles, and that each set is transported in an alternate manner. Continentally derived NO3− is transported as coarse particle to the east Asian Pacific Rim region. Anthropogenic pollutants and dust particles are not necessarily transported together. It was often found that anthropogenic fine particles containing abundant nss‐SO42− appeared first and were then followed by large mineral particles that had absorbed NO3−. Short‐term intrusion of the air masses containing abundant particulate carbonaceous compounds, probably due to the influence of biomass burning, also often occurred during the outflow events of continental air masses. Atmospheric behaviors of sulfate, nitrate, and carbonaceous species are different from one another, although they are all derived mainly from combustion processes.
Connections between the summer east African and Indian rainfall regimes
Authors: Vizy Edward K. , Cook Kerry H.
Published: August 2003

Rainfall over parts of east Africa and India is observed to be positively correlated and associated with variations in the low‐level height field over the northern Indian Ocean and the Arabian Peninsula. A regional climate model is used to understand the mechanisms of this covariability. SST anomalies in the Arabian Sea are imposed to generate anomalies to analyze. Variations in the monsoon trough, which is located over east Africa extending eastward to southeastern Asia, regulate the connection between east Africa and India and mediate the precipitation covariability in the model. When the monsoon trough is weak, northern Ethiopia and western India are dry, in association with a weaker Somali jet, but rainfall is enhanced over southern Ethiopia. Over east Africa, rainfall decreases over northern Ethiopia are related to increased dry air advection from the north. The atmospheric response when the monsoon trough is strong is not the opposite of the weak trough simulation as conditions are wetter over West India, but drier over all of Ethiopia. Hydrodynamical processes including latent heating are more influential in the vicinity of the western Indian Ocean when the monsoon is perturbed by warm Arabian Sea SSTAs.
A global aerosol model forecast for the ACE‐Asia field experiment
Authors: Chin Mian , Ginoux Paul , Lucchesi Robert , Huebert Barry , Weber Rodney , Anderson Tad , Masonis Sarah , Blomquist Byron , Bandy Alan , Thornton Donald
Published: August 2003

We present the results of aerosol forecast during the ACE‐Asia field experiment in spring 2001, using the Georgia Tech/Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model and the meteorological forecast fields from the Goddard Earth Observing System Data Assimilation System (GEOS DAS). The model provides direct information on aerosol optical thickness and concentrations for effective flight planning, while feedbacks from measurements constantly evaluate the model for successful model improvements. We verify the model forecast skill by comparing model‐predicted aerosol quantities and meteorological variables with those measured by the C‐130 aircraft. The GEOS DAS meteorological forecast system shows excellent skills in predicting winds, relative humidity, and temperature, with skill scores usually in the range of 0.7–0.99. The model is also skillful in forecasting pollution aerosols, with most scores above 0.5. The model correctly predicted the dust outbreak events and their trans‐Pacific transport, but it constantly missed the high dust concentrations observed in the boundary layer. We attribute this “missing” dust source to desertification regions in the Inner Mongolia Province in China, which have developed in recent years but were not included in the model during forecasting. After incorporating the desertification sources, the model is able to reproduce the observed boundary layer high dust concentrations over the Yellow Sea. We demonstrate that our global model can not only account for the large‐scale intercontinental transport but also produce the small‐scale spatial and temporal variations that are adequate for aircraft measurements planning.
Thermal infrared emission spectroscopy of titanium‐enriched pyroxenes
Authors: Hamilton V. E.
Published: August 2003

Pyroxenes are useful indicators of igneous processes and may be identified in geologic materials in the laboratory or remotely through the use of spectroscopic analysis. Studies of the thermal infrared (vibrational) spectra of many compositions in the pyroxene solid solution series (quadrilateral orthopyroxene and clinopyroxene, and some nonquadrilateral compositions) have shown that spectral absorption features shift in wavelength position, vary in number, and change shape as a function of pyroxene silicate structure and cation substitution. These spectral variations can be used to identify the approximate composition(s) of pyroxenes in the thermal infrared emission spectra of rocks. Here I demonstrate that the spectra of Ti‐rich calcic clinopyroxenes also have thermal infrared spectral characteristics that distinguish them from typical quadrilateral compositions via a comparison to the spectrum of Angra dos Reis, a meteorite dominated by Ti‐enriched clinopyroxene. The distinctive spectral character of Ti‐rich pyroxenes may permit their identification not only in laboratory mineral and rock samples but also in thermal infrared remote sensing data, providing additional chemical information about igneous lithologies.
Aggregation of human platelets in plasma by porcine blood cells in vitro is probably mediated by thrombin generation
Authors: Benatuil Lorenzo , Fernandez Ana Z. , Romano Egidio
Published: August 2003

Abstract: The infusion of pig progenitor cells into baboons is associated with a thrombotic microangiopathy probably related to the interaction of these cells with the baboon endothelial cells and platelets. We have shown previously that pig peripheral blood mononuclear cells (p‐PBMC), are able to activate the human coagulation cascade as they are able to generate thrombin when added to defibrinated plasma. In this work, we have tested the interaction of p‐PBMC with human platelets to assess the capacity of p‐PBMC to cause platelet aggregation and the possible role of complement activation in this aggregation. Human platelet aggregation assays, using collagen (1 or 2 µg/ml), were performed with platelets in platelet‐rich plasma (PRP) or platelets washed by filtration. PRP or washed platelets were also incubated with p‐PBMC or human PBMC (h‐PBMC) at several concentrations and aggregation was measured. The effect of Dansylarginine N‐(3‐ethyl‐1,5‐pentanediyl)amide (DAPA), an inhibitor of thrombin, was studied on platelet aggregation caused by the pig cells. Complement activation was measured by deposition of fragment c derived from C3 splitting (C3c) on pig cells incubated with citrated platelet poor plasma (PPP). When human PRP was incubated with p‐PBMC, aggregation was a consistent event quantitatively similar to that induced by collagen. No aggregation of washed platelets was observed when these were incubated with p‐PBMC or h‐PBMC. Aggregation of human platelets in PRP, induced by p‐PBMC, was inhibited when DAPA (100 μm) was added to the incubation mixture (23%), indicating that the thrombin inhibitor blocked the capacity of p‐PBMC to aggregate human platelets. No deposition of C3c fragments on p‐PBMC was detected when the porcine cells were incubated for up to 20 min with citrated PPP. The fact is that p‐PBMC induces human platelet aggregation in plasma being thrombin generation a likely explanation for this observation. Our data suggest that, in the system assayed, complement activation is not a cause of platelet aggregation. These findings are relevant for the clarification of the reported thrombotic microangiopathy complicating the intravenous infusion of pig cells in primates in attempts to induce pig tolerance in baboons.
Ex vivo and extracorporeal perfusion with hDAF pig kidneys*
Authors: Luo Yigang , Levy Gary , Garcia Bertha M. , Yang Hongji , Phillips James , Noble Lee , Chakrabarti Subrata , Grant David , Zhong Robert
Published: August 2003

The present study was undertaken to determine whether human decay accelerating factor (hDAF) transgene would prevent hyperacute rejection (HAR) while perfused with human blood or extracorporeally in baboons. Four hDAF pig kidneys and three non‐hDAF pig kidneys were perfused ex vivo with fresh human blood for 6 h. Additionally four hDAF pig kidneys and four non‐hDAF pig kidneys were extracorporeally perfused in baboons and pigs, respectively, for 3 h. In ex vivo perfusion, the color of hDAF pig kidneys remained pink at the end of 6‐h perfusion and they had normal histology, while non‐hDAF kidneys developed HAR. HDAF pig kidneys had superior function over non‐transgenic pig kidneys. Urine output was 17.31 ± 3.70 ml/h for hDAF pig kidneys, and only 5.81 ± 0.26 ml/h for non‐hDAF kidneys (P < 0.05). Creatinine clearance was 1.16 ± 1.24 ml/min for hDAF kidneys and 0.22 ± 0.15 ml/min for non‐hDAF kidneys (P < 0.05). Other functional data including potassium, urine specific density, and osmolality were normal in the hDAF kidneys, while in non‐hDAF kidneys, serum potassium was elevated to over 9 mmol/l by the end of perfusion (P < 0.01). Non‐hDAF kidneys also lost more sodium through urine than hDAF kidneys (173.67 ± 14.05 mmol/l vs. 109 ± 31 mmol/l, P < 0.05). In the extracorporeal perfusion, all the baboons tolerated the procedure well with normal hemodynamic and hemotologic profiles. These baboons were well until killed 42 to 56 days after perfusion, although their antiporcine antibodies were greatly elevated. We conclude that hDAF transgene protects against HAR, allowing the pig kidney to function normally while perfused with human blood, and that extracorporeal perfusion using hDAF pig kidneys is a safe procedure in baboons.
Release of pig leukocytes during pig kidney perfusion and characterization of pig lymphocyte carbohydrate xenoantigens
Authors: Magnusson Stefan , Månsson Jan‐Eric , Strokan Valeri , Jussila Rainer , Kobayashi Takaaki , Rydberg Lennart , Romano Egidio , Breimer Michael E.
Published: August 2003

Abstract: The Galα1–3Gal (αGal) antigen is considered the main xenoantigen in the pig to human species combination but other porcine antigens have to be considered such as the swine lymphocyte antigen (SLA), the blood group A/O and the Hanganutziu–Deicher (H–D) antigens. The H–D antigens are N‐glycolyl‐neuraminic acid (NeuGc) terminated gangliosides that are widely distributed in mammalian species but absent in humans. Upon exposure to a vascularized pig organ, the human recipient can be immunized by direct interaction with the pig tissue or/and by transfer of tissue/cells from the organ into the recipient. In the present work, we describe the release of cells from porcine kidneys upon perfusion and the expression of glycolipid based αGal, blood group A/O and H–D antigens in pig lymphocytes. Pig kidneys were flushed with 20 ml of NaCl or Lidocain containing 5000 U heparin, and thereafter perfused with 3000‐ml perfusion solution and the cells released were counted and examined microscopically. Neutral glycolipid and ganglioside fractions were extracted from purified pig lymphocytes. The extracted components were characterized by thin layer chromatography, degradation and mass spectrometry. The expression of αGal and H–D epitopes on cells released from pig kidneys and purified pig lymphocytes were studied by immune electron microscopy. A total amount of about 300 × 106 leukocytes, mainly lymphocytes were released in the perfusate from the kidneys, of which about 100 × 106 cells were eluated in the 600 to 2400 ml perfusate fraction. Immunelectron microscopical analysis with Griffonia simplicifolia isolectin B4 showed staining of pig leukocytes and other cells, morphologically similar to endothelial cells, released in the perfusate. The purified porcine lymphocytes contained 930 μg neutral glycolipid (4.2 μg/mg cell protein) of which 95% was glycolipids with one to four sugar residues. Immunostaining of the neutral glycolipid fractions revealed αGal terminated compounds migrating in the five and 10 to 12 sugar regions and blood group A compounds in the six and eight sugar regions. Two major gangliosides NeuGc‐GM3 and NeuGc‐GD3 were found in the pig lymphocytes. In a patient extracorporeally xenoperfused with a pig kidney, an increased staining of both αGal terminated structures as well as the H–D reactive gangliosides were found in the post‐perfusion serum samples. In summary, leukocytes, mainly lymphocytes are released from pig kidneys during perfusion which may contribute to immunization of human xenograft recipients.
Cellular inflammatory response to porcine collagen membranes
Authors: Patino Maria G. , Neiders Mirdza E. , Andreana Sebastiano , Noble Bernice , Cohen Robert E.
Published: August 2003

Objectives:  The purpose of this study was to assess local inflammatory changes associated with the implantation of three different porcine collagen membranes having potential use in periodontal regeneration.

Methods:  Materials were implanted subcutaneously into prepared sites along the dorsal skin surface of 60 female Wistar rats. Saline and turpentine were used as negative and positive controls, respectively. Animals were killed and biopsies obtained after 3 d, and at 1, 2, 4, 6, and 8 weeks after membrane implantation. A panel of six monoclonal antibodies was used to identify circulating monocytes (ED1), resident tissue macrophages (ED2), lymphoid macrophages (ED3), Ia‐antigen expression (OX6), T‐lymphocytes (OX19), and B‐lymphocytes (OX33). Cells identified by each antibody were subjected to quantitative immunocytochemistry to compare any differences present among groups. Sera obtained 8 weeks after grafting were used in immunoblotting assays to detect the presence of systemic antiporcine antibodies.

Results:  We found that the mononuclear cell subsets associated with implantation of porcine collagen membranes were similar to those obtained with saline administration. On the other hand, the use of turpentine resulted in an inflammatory infiltrate characterized by significantly higher numbers of all six monoclonal cell subsets at all time periods evaluated, compared to either saline or any of the membranes (P < 0.001).

Conclusions:  The collagen membranes do not appear to be associated with a significant local inflammatory response, nor a systemic immune response, and thus appear to be well tolerated, rendering them useful in periodontal regeneration.
Endpoint quantitative PCR assays for Bacteroides forsythus, Porphyromonas gingivalis, and Actinobacillus actinomycetemcomitans
Authors: Rudney J. D. , Chen R. , Pan Y.
Published: August 2003

Background:  Conventional polymerase chain reaction (PCR) assays for periodontal pathogens are so sensitive that they detect infections of no clinical significance. Quantitative PCR (qPCR) may provide a solution to this problem. However, most qPCR systems require expensive real‐time thermal cyclers.

Objective:  Our goal was to develop qPCR assays which would allow endpoint quantification.

Materials and methods:  16S rRNA primers for Bacteroides forsythus, Porphyromonas gingivalis, and Actinobacillus actinomycetemcomitans were adapted to the Amplifluor™ qPCR system, which incorporates fluorescein into the PCR product so that endpoint fluorescence is proportional to the original amount of template. DNA dilutions representing known numbers of cells were used as standard curves. Pooled subgingival plaques from the four deepest pockets of 21 severe adult periodontitis patients were assayed. Buccal molar supragingival plaque from 35 dental students provided healthy controls. Endpoint fluorescence was measured with a microplate reader.

Results:  Optimized standard curves were linear in log–log or semilog fits over a range of 100–106 cells. Countable B. forsythus was present in all patients, with counts (as logs) from 2.4 to 7.3 (mean = 5.0), and 11 controls with counts from 2.1 to 4.5 (mean = 3.0). P. gingivalis was present in 11 patients and no controls, with counts from 2.2 to 4.7 (mean = 3.2). A. actinomycetemcomitans was present in two patients, with counts of 1.5 and 3.5.

Conclusions:  Amplifluor™ qPCR assays discriminated between plaque samples differing by one log or more, allowing major infections to be distinguished from minor ones. This approach allows high‐throughput qPCR of plaque samples, using equipment available to many laboratories.
Immunoglobulin G profiles in different forms of periodontitis
Authors: Chung Hsien‐Yang , Lu Hsi‐Chi , Chen Woan‐Ling , Lu Chun‐Tai , Yang Yi‐Hsin , Tsai Chi‐Cheng
Published: August 2003

Background:  Races and Gm(23) allotypes can modify the serum levels of IgG subclasses. The average serum levels of IgG subclasses of African‐Americans have been reported to be higher than those of Caucasians in both healthy young adults and patients with aggressive periodontitis; Gm(23)‐positive subjects generally had higher IgG2 levels than Gm(23)‐negative subjects.

Objective:  We examined serum immunoglobulin G (IgG) concentrations in Taiwanese patients with different forms of periodontitis.

Methods:  The serum levels of four IgG subclasses were determined by enzyme‐linked immunosorbent assay and Gm(23) allotypes were verified by radial immunodiffusion tests in 50 patients with chronic periodontitis, 30 patients with aggressive periodontitis, and 74 healthy controls.

Results:  There were no differences in the concentrations of four IgG subclasses in patients with chronic periodontitis compared with age‐matched controls. However, in subjects younger than 35 years, levels of IgG2 were significantly elevated in patients with aggressive periodontitis compared with controls. We also found significant differences in IgG2 levels within the control group when stratified by age (≤ 35 years and > 35 years). Gm(23) allotypes were not correlated with the serum levels of IgG2 in either patient group.

Conclusion:  Microbial challenge might not provoke significant changes in systemic IgG response in patients with chronic periodontitis. However, in patients with aggressive periodontitis, IgG2 levels were increased when compared with age‐matched controls. Gm(23) allotypes had no influence on IgG2 levels in well‐established generalized chronic periodontitis or aggressive periodontitis.
Decreased expression of α2 integrin in fibroblasts isolated from cyclosporin A‐ induced gingival overgrowth in rats
Authors: Kataoka Masatoshi , Seto Hiroyuki , Wada Chie , Kido Jun‐ichi , Nagata Toshihiko
Published: August 2003

Objectives:  Cyclosporin A (CsA), an immunosuppressive agent, induces fibrous gingival overgrowth through reduction of collagen phagocytosis by fibroblasts. Distinct receptors are involved in the binding of collagen to fibroblasts in collagen phagocytosis, and α2β1 integrin serves as a specific receptor for type I collagen on fibroblasts. To elucidate the role of α2β1 integrin in CsA‐induced gingival overgrowth, we investigated collagen phagocytosis and α2β1 integrin expression in rat gingival fibroblasts.

Materials and methods:  Fibroblats were isolated from gingiva of rats fed a powdered diet containing or lacking CsA for 30 d. Flow cytometric analysis were performed to measure the collagen phagocytosis and the α2 integrin expression in fibroblasts. Furthermore, total RNAs were isolated from fibroblasts, and the reverse transcriptase‐polymerase chain reaction was employed to investigate the mRNA levels of α2 integrin.

Results:  In vitro collagen phagocytosis assay revealed that CsA‐treated and control fibroblasts contained a mean of 13.5% and 36.1% phagocytic cells, respectively. CsA‐treated fibroblasts had 28% lower expression of α2 integrin than that of control. and mRNA expression of α2 integrin in CsA‐treated fibroblasts was apparently lower than in the controls, but the mRNA expression of β1 integrin was not affected.

Conclusion:  These findings suggest that one etiological factor of gingival overgrowth may be inhibition of collagen phagocytosis by reducing α2 integrin expression in gingival fibroblasts.
Modulation of resistance to idarubicin by the cyclosporin PSC 833 (valspodar) in multidrug‐resistant cells
Authors: Lacayo Norman J. , Duran George E. , Sikic Branimir I.
Published: August 2003

Idarubicin (IDA) is an anthracycline anticancer drug utilized in the treatment of acute leukemias. There are conflicting data published with regard to the cross‐resistance of IDA in multidrug‐resistant (MDR) cells expressing P‐glycoprotein (P‐gp). We evaluated the cytotoxicity and cellular accumulation of IDA in a panel of anthracycline‐selected MDR cell lines. Leukemia K562/R7 cells and sarcoma MES‐SA/Dx5 cells expressing high levels of the MDR1 (ABCB1) gene were resistant to IDA (42‐fold and 150‐fold, respectively). In both of these cell lines, resistance to IDA was equivalent to that for doxorubicin, the drug used to select for the MDR variants. The P‐gp inhibitor PSC 833 (valspodar) at 2 μM completely restored sensitivity to IDA. IDA accumulation was decreased 12‐fold in MES‐SA/Dx5 cells vs parental cell line, and drug uptake was restored to control levels by PSC 833. Reduced intracellular IDA was correlated with P‐gp content by flow cytometry. Experiments in NIH3T3 murine cells transfected with the human MDR1 gene substantiated the findings of cross‐resistance to IDA and reversal of resistance by PSC 833. Our data indicate that IDA is a high‐affinity substrate for P‐gp.
Smoke or fog? The usefulness of retrospectively reported information about smoking
Authors: Kenkel Donald , Lillard Dean R. , Mathios Alan
Published: August 2003

Aims  To investigate the reliability and validity of retrospectively reported information on smoking.

Design  Nationally representative retrospective data from longitudinal surveys and contemporaneous data from repeated cross‐sectional surveys were used.

Participants  Adult respondents to three of the four samples of the National Longitudinal Surveys Original Cohort 1966–68; the National Longitudinal Survey of Youth 1979; and various waves of the US National Health Interview Survey.

Measurements  Reliability was investigated by calculating kappa statistics for repeated measures of ever‐smoking and annual‐smoking status. Validity was investigated by comparing smoking prevalence rates generated by retrospective data with contemporaneously measured rates.

Findings  Kappa statistics indicated the repeated measures of ever‐smoking status show substantial agreement; repeated measures of annual‐smoking status show moderate agreement. Retrospective reports on smoking behavior produced prevalence rates that match reasonably well with those from contemporaneous reports of smoking behavior.

Conclusions  Retrospective data on smoking can be an important resource for tobacco addiction research.
Impacts of federal ephedrine and pseudoephedrine regulations on methamphetamine‐related hospital admissions
Authors: Cunningham James K. , Liu Lon‐Mu
Published: August 2003

Aims  To determine whether the federal regulation of ephedrine and pseudoephedrine, precursors used in illicit methamphetamine production, reduced methamphetamine‐related acute care hospital admissions.

Design  ARIMA‐intervention time‐series analysis.

Setting  California (1983–2000), Arizona and Nevada (1991–2000), USA.

Measurements  Monthly counts of methamphetamine‐related acute care hospital admissions.

Interventions  Bulk powder ephedrine and pseudoephedrine: regulated November 1989. Products containing ephedrine as the single active medicinal ingredient: regulated August 1995. Products containing pseudoephedrine:

regulated October 1997. Large‐scale producers used ephedrine and pseudoephedrine in these forms. Ephedrine combined with other active medicinal ingredients (e.g. various cold medicines), used mainly by small‐scale producers: regulated October 1996.

Findings  In California, the bulk powder regulation stopped a 7‐year rise in admissions (1983–89) and reduced them by 35% (P < 0.01). The single ingredient ephedrine regulation stopped a 4‐year rise (1992–95) in California, Arizona and Nevada, with 48% (P < 0.01), 71% (P < 0.01) and 52% (P < 0.01) reductions, respectively. The pseudoephedrine products regulation stopped a 2‐year rise (1996–97) in California, Arizona and Nevada, with 38% (P < 0.01), 41% (P < 0.05) and 61% (P < 0.01) reductions, respectively. Admissions rose at the end of the study period but were still well below peak 1990s levels. The regulation of ephedrine combined with other active medicinal ingredients had no significant impact in any of the three states.

Conclusions  Regulations targeting precursors used by large‐scale producers reduced admissions substantially during the study period. However, the regulation of precursors used primarily by small‐scale producers had little, if any, effect.
Alcohol consumption and liver cirrhosis mortality with and without mention of alcohol—the case of Canada
Authors: Ramstedt Mats
Published: August 2003

Aims  To analyse post‐war variations in per capita alcohol consumption in relation to gender‐specific liver cirrhosis mortality in Canadian provinces and to assess the extent to which alcohol bears a different relation to cirrhosis deaths with mention of alcohol (alcoholic cirrhosis) compared to cirrhosis deaths without mention of alcohol (non‐alcoholic cirrhosis).

Data and method  Annual liver cirrhosis mortality rates by 5‐year age groups were converted into gender‐specific and age‐adjusted mortality rates. Outcome measures included total cirrhosis—the conventional measure of liver cirrhosis—alcoholic cirrhosis and non‐alcoholic cirrhosis. Per capita alcohol consumption was measured by alcohol sales and weighted with a 10‐year distributed lag model. A graphical analysis was used to examine the regional relationship and the Box–Jenkins technique for time‐series analysis was used to estimate the temporal relationship.

Findings  Geographical variations in alcohol consumption corresponded to variations in total liver cirrhosis and particularly alcoholic cirrhosis, whereas non‐alcoholic cirrhosis rates were not associated geographically with alcohol consumption. In general, for all provinces, time‐series analyses revealed positive and statistically significant effects of changes in alcohol consumption on cirrhosis mortality. In Canada at large, a 1‐litre increase in per capita consumption was associated with a 17% increase in male total cirrhosis rates and a 13% increase in female total cirrhosis rates. Alcohol consumption had a stronger impact on alcoholic cirrhosis, which increased by fully 30% per litre increase in alcohol per capita for men and women. Although the effect on the non‐alcoholic cirrhosis rate was weaker (12% for men and 7% for women) it was nevertheless statistically significant and suggests that a large proportion of these deaths may actually be alcohol‐related.

Conclusions  Some well‐established findings in alcohol research were confirmed by the Canadian experience: per capita alcohol consumption is related closely to death rates from liver cirrhosis and alcohol‐related deaths tend to be under‐reported in mortality statistics.
The relationship of average volume of alcohol consumption and patterns of drinking to burden of disease: an overview
Authors: Rehm Jürgen , Room Robin , Graham Kathryn , Monteiro Maristela , Gmel Gerhard , Sempos Christopher T.
Published: August 2003

Aims  As part of a larger study to estimate the global burden of disease attributable to alcohol:

to quantify the relationships between average volume of alcohol consumption, patterns of drinking and disease and injury outcomes, and

to combine exposure and risk estimates to determine regional and global alcohol‐attributable fractions (AAFs) for major disease and injury categories.

Design, methods, setting  Systematic literature reviews were used to select diseases related to alcohol consumption. Meta‐analyses of the relationship between alcohol consumption and disease and multi‐level analyses of aggregate data to fill alcohol–disease relationships not currently covered by individual‐level data were used to determine the risk relationships between alcohol and disease. AAFs were estimated as a function of prevalence of exposure and relative risk, or from combining the aggregate multi‐level analyses with prevalence data.

Findings  Average volume of alcohol consumption was found to increase risk for the following major chronic diseases: mouth and oropharyngeal cancer; oesophageal cancer; liver cancer; breast cancer; unipolar major depression; epilepsy; alcohol use disorders; hypertensive disease; hemorrhagic stroke; and cirrhosis of the liver. Coronary heart disease (CHD), unintentional and intentional injuries were found to depend on patterns of drinking in addition to average volume of alcohol consumption. Most effects of alcohol on disease were detrimental, but for certain patterns of drinking, a beneficial influence on CHD, stroke and diabetes mellitus was observed.

Conclusions  Alcohol is related to many major disease outcomes, mainly in a detrimental fashion. While average volume of consumption was related to all disease and injury categories under consideration, pattern of drinking was found to be an additional influencing factor for CHD and injury. The influence of patterns of drinking may be underestimated because pattern measures have not been included in many epidemiologic studies. Generalizability of the results is limited by methodological problems of the underlying studies used in the present analyses. Future studies need to address these methodological issues in order to obtain more accurate risk estimates.
Experimental and numerical study of water flow in soil under irrigation in northern Senegal: evidence of air entrapment
Authors: Hammecker C. , Antonino A.C.D. , Maeght J.L. , Boivin P.
Published: August 2003

Irrigation by surge flooding does not always wet the soils thoroughly, and we have investigated the reasons for this on an irrigated plot in northern Senegal by monitoring the water budget during a rice cropping season (100 days). The amount of water added during each irrigation event was measured, and evapotranspiration and infiltration were estimated with lysimeters and Muntz infiltration rings, respectively. At the same time, piezometric levels, neutron probe values and water tension data were recorded at two stations in the plot. These measurements showed unusual results: infiltration rate was less than 1 × 10−6 mm s−1 (less than 0.1 mm a day), there was a constant water deficit during the entire irrigation period, around 50 cm deep, and tensiometers at 40 cm reacted very slowly to water infiltration. The water fluxes in the vadose zone derived from these data showed clearly a discrepancy between fluxes calculated from hydraulic gradients and fluxes calculated from mass conservation. The hydraulic gradients suggested a zero flux plane at 40 cm below the surface, but the calculated values of the fluxes overestimated by several orders of magnitude the infiltration rates determined on the plot, whereas fluxes determined from mass conservation matched far better. These results show that air was entrapped between the shallow water table and the wetting front, and this inhibited water infiltration. Modelling water flow down the soil profile with a computer program for simulating one‐dimensional water movement (Hydrus) confirmed that single‐phase models cannot describe imbibition in this situation. Simple infiltration models based on a modified Green–Ampt equation accounting for air compression and air counter‐flow, however, fit experimental infiltration data much better. We demonstrated that where surge flooding is associated with a shallow water table, as in many large irrigation schemes, one must take into account the presence of air to quantify the flow of water into the soil.
An improved simulation of void structure, water retention and hydraulic conductivity in soil with the Pore‐Cor three‐dimensional network
Authors: Johnson A. , Roy I. M. , Matthews G. P. , Patel D.
Published: August 2003

We present a new method of characterizing the void structures of soils from water retention curves as the primary source of data. The method avoids the problems of other current approaches, which use smoothing curves and can miss the subtleties of soil structure, and usually ignore the shielding of large pores by the small connecting throats surrounding them. In the new method, software we have named ‘Pore‐Cor’ is used to generate simple three‐dimensional networks of voids that have the same water retention characteristics and porosities as the soils. To find the geometry of the required networks, we have introduced a Boltzmann‐annealed simplex which works in four parametric and three Boolean dimensions of parameter space. Also, a more robust measure of the difference between the experimental and simulated water retention curves has been developed. The method is applied to water retention curves for a wide range of English and Welsh soils, both experimental and generated from a pedotransfer function. The resulting simulated void structures have void sizes that change as expected across the soil texture diagram, have different structures as highlighted by the locations of retained water, but have connectivities (number of connecting throats per pore) that vary little. A wide range of other calculations of wetting and non‐wetting fluid transport properties, and calculations of the behaviour of fluid‐borne pollutants, are now possible. The main bar to further progress is a lack of sufficiently accurate and comprehensive data for water retention, and for saturated and unsaturated hydraulic conductivity.
Hydrochemistry of runoff and subsurface flow within Sahelian microdunes
Authors: Ribolzi O. , Bariac T. , Casenave A. , Delhoume J. P. , Ducloux J. , VallÈs V.
Published: August 2003

The sandy microdune systems of the Sahel are important for biomass production, in that they trap and store water. We have studied the movement of water over and in a dune and the chemistry of the water to understand this aspect of the systems. We experimented with simulated rain using a field sprinkling infiltrometer. We applied demineralized water with a chemical composition similar to that of the natural rain on a 1‐m2 plot. The plot was delimited by a metallic two‐level setting: the first enabled us to collect surface runoff, while the second measured subsurface flow. Water samples were taken at 5‐ to 10‐minute intervals throughout each simulation for chemical analysis (alkalinity, SO42–, F–, NO3–, Ca2+, Mg2+, Na+, K+ and Si). Mass balances, combined with a simple mixture model involving one tracer (chloride) and two reservoirs (old and new waters), were calculated. The equilibrating pressures of the CO2 (pCO2) and the saturation index with respect to specified minerals (e.g. calcite, fluorite, silicates) were also calculated by the AQUA ion‐pair model. The solute concentrations decrease in surface runoff as well as in subsurface water, except for F– and Si in the subsurface. The pCO2 decreased to a pressure less than the atmospheric pressure. The difference between measured concentrations and concentrations computed with the mixing model highlighted interactions between the soil and water. The dissolution of calcite which consumes CO2, and the cation exchanges, dominated, whereas the dissolutions of fluorite, silicates and gypsum appear secondary. Reactive mineral stocks were quickly exhausted, especially in the surface flow.
Relationship between thermal conductivity and water content of soils using numerical modelling
Authors: Cosenza P. , Guérin R. , Tabbagh A.
Published: August 2003

There is no simple and general relationship between the thermal conductivity of a soil, λ, and its volumetric water content, θ, because the porosity, n, and the thermal conductivity of the solid fraction, λs, play a major part. Experimental data including measurements of all the variables are scarce. Using a numerical modelling approach, we have shown that the microscopic arrangement of water influences the relation between λ and θ. Simulated values for n ranging from 0.4 to 0.6, λs ranging from 2 to 5 W m−1 K−1 and θ from 0.1 to 0.4 can be fitted by a simple linear formula that takes into account n, λs and θ. The results given by this formula and by the quadratic parallel (QP) model widely used in physical property studies are in satisfactory agreement with published data both for saturated rocks and for unsaturated soils. Consequently, the linear formula and the QP model can be used as practical and efficient tools to investigate the effects of water content and porosity on the thermal conductivity of the soil and hence to optimize the design of thermal in situ techniques for monitoring water content.
Isotope methods for assessing plant available phosphorus in acid tropical soils
Authors: Bühler S. , Oberson A. , Sinaj S. , Friesen D. K. , Frossard E.
Published: August 2003

Use of isotope methods to measure the availability of phosphorus (P) in soils that are well supplied with P is well established. We have evaluated such methods for acid tropical soils with very small P contents, which are less well studied. The isotopically exchangeable P in soil suspensions (E value) and that in plant growth experiments (L value) were measured in soils that had received varying amounts of P fertilizer in two field experiments in Colombia. We determined the E values over 4–5 weeks of equilibration allowing for the kinetics of isotope exchange. The decrease in radioactivity in the soil solution at a particular time, t, divided by that at the start (rt/R) was described by three parameters (r1/R, r∞/R, and a coefficient n) derived from the time course of isotopic exchange over 100 minutes. Values of Et were calculated either from measured values of rt/R or those extrapolated until 12 weeks. Agrostis capillaris was grown on the same soils labelled with carrier‐free 33P‐orthophosphate ions to obtain L values. Agreement between E values derived from measured and extrapolated values of rt/R was satisfactory, but errors in n and r∞/R limited the precision with which we could estimate E values. For most soils, the P concentrations in the soil solution were greater than the detection limit of the malachite green method (0.9 µg l−1) but smaller than its quantification limit (3.6 µg l−1). In the soils with the least available P, the P content of the seed limited the determination of the L value. The E values were strongly correlated, but not identical, with the L values measured for the same time of isotopic exchange. We conclude that these approaches are not precise enough to detect in these soils the ability of a plant to access slowly exchangeable forms of P or to quantify the mineralization of organic P. However, these isotope techniques can be used to estimate the total fraction of added fertilizer P that remains available to the plants.
Uncoupling of the ATPase activity from the branch migration activity of RuvAB protein complexes containing both wild‐type and ATPase‐defective RuvB proteins
Authors: Hishida Takashi , Iwasaki Hiroshi , Han Yong‐Woon , Ohnishi Takayuki , Shinagawa Hideo
Published: August 2003

Background:  Escherichia coli RuvAB promotes branch migration of Holliday junctions during recombination repair and homologous recombination. RuvB forms a hexameric ring through which duplex DNA passes and is translocated in an ATP‐dependent manner. ATPase‐deficient RuvB mutant K68A has a mutation in the Walker A motif and exerts a dominant‐negative effect on in vivo repair of UV‐induced DNA damage. In this study, we examined RuvAB‐dependent branch migration in the presence of a mutant RuvB, K68A.

Results:  Mixing K68A with wild‐type RuvB resulted in the formation of heterohexamers that showed unique properties of DNA binding, ATPase, and branch migration activities different from those of either wild‐type or mutant homohexamers. RuvB heterohexamers inhibited branch migration and caused Holliday junctions to accumulate during RecA‐mediated strand exchange. In the presence of RuvA, RuvB heterohexamers had Holliday junction‐dependent ATPase activity, but did not promote branch migration.

Conclusions:  These results suggest that functional cooperation among the subunits in the hexamers is required for branch migration, but inclusion of inactive subunits is tolerated for ATP hydrolysis. Therefore, we propose that an essential ATP hydrolysis‐dependent functional cooperation is induced in RuvB hexamer subunits during RuvAB‐mediated branch migration.
Glycophorin A requirement for expression of O‐linked antigens on the erythrocyte membrane
Authors: Arimitsu Nagisa , Akimitsu Nobuyoshi , Kotani Norihiro , Takasaki Seiichi , Kina Tatsuo , Hamamoto Hiroshi , Kamura Koushirou , Sekimizu Kazuhisa
Published: August 2003

Background:  Glycophorin A (GPA) has a large number of sialic acid‐containing oligosaccharide chains. GPA is highly conserved among vertebrates, mice with a GPA deletion have not been reported and GPA's physiologic role remains uncertain.

Results:  GPA−/− homozygotes were obtained by intercrossing GPA+/− heterozygotes based on Mendelian genetics. The amount of O‐linked oligosaccharide chains in the erythrocyte membrane of GPA−/− mice decreased to 60% compared to that of the wild‐type mice.

Flow cytometry and Western blot analysis revealed that the TER antigen that is associated with GPA on the erythrocyte membrane was totally abrogated from the cell surface in GPA−/− mice. Several glycoproteins that were detected with peanut agglutinin (PNA), a lectin that recognizes O‐linked oligosaccharide chains, were absent from the GPA−/− erythrocyte membrane. Erythrocytes lacking GPA were more sensitive to hypo‐osmotic stress than wild‐type erythrocyte.

Conclusions:  GPA−/− mice show apparently normal phenotypes at least during the early generations. The disappearance of many glycoproteins recognized by PNA lectin on the GPA−/− erythrocyte membrane proteins suggests that GPA has an essential role in the expression of O‐linked antigens on the erythrocyte membrane protein. These interactions of GPA and other glycoproteins may contribute to maintaining the physical strength of the erythrocyte membrane.
medline on CD‐ROM: resource or red herring?
Authors: WHITSED NICKY
Published: August 2003

Faced with ever‐increasing development in technology and dwindling library budgets, British medical librarians are now considering the possibility of providing an in‐house medline service based on CD‐ROM technology. This raises a variety of issues concerned with end‐user searching, particularly the quality of searching, and poses questions relating to the volatile nature of technology. This paper describes the CD‐ROM product, the problems implementation has raised, and draws on experiences of American end‐user use of mini‐medline.
Educational videotape: a medium full of promise and riddled with pitfalls
Authors: WILL DAVID , WRATE ROBERT M.
Published: August 2003

The role of educational videotape for interactive group learning is discussed and the authors' experience in producing and marketing their own videotapes is described. A videotape users' network to assist those wishing to exploit the medium effectively is proposed.