bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pharmacokinetics of cathinone, cathine and norephedrine after the chewing of khat leaves
Authors: Toennes Stefan W. , Harder Sebastian , Schramm Markus , Niess Constanze , Kauert Gerold F. 
Published: July 2003

Aim  The stimulating herbal drug khat is habitually used in East Africa and the Arabian peninsula but is also imported into other countries. The aim was to study the pharmacokinetics of its alkaloids cathinone, cathine and norephedrine.Methods  Four volunteers chewed khat leaves in an amount equivalent to one‐quarter of that used in a typical khat session. Blood samples were collected up to 80 h and the alkaloids were assayed using gas chromatography‐mass spectrometry. The data were evaluated using computerized pharmacokinetic compartmental analysis.Results  The plasma concentration‐time data for the alkaloids could be described using a two‐compartment model with two‐segment absorption. The mucosa of the oral cavity is considered to be the first absorption segment, where the major proportion of the alkaloids is absorbed (mean ± SD 59 ± 21% for cathinone and 84 ± 6% for cathine). The extraction of the alkaloids from the leaves by chewing was very effective with only 9.1 ± 4.2% remaining as a residue. Cathinone was eliminated from the central compartment with a mean half‐life of 1.5 ± 0.8 h. The half‐life of cathine was 5.2 ± 3.4 h. The metabolism of cathinone to norephedrine had a substantial influence on its plasma concentration profile. Psychophysical functions were essentially unaffected by the chewing of khat.Conclusions  The pharmacokinetics of khat alkaloids in humans explain why chewing is the preferred form of khat ingestion. Subjects absorbed a mean dose of 45 mg of cathinone, and did not suffer any severe adverse reactions.
The child's – or the state's – best interests? An examination of the ways immigration officials work with unaccompanied asylum seeking minors in Norway
Authors: Engebrigtsen Ada 
Published: July 2003

ABSTRACTThis article questions the way in which Norwegian immigration officials apply the principle of the child's best interests in cases concerning family reunion for unaccompanied asylum seeking minors in Norway. It is claimed that the official definition of child migrants and the interpretation of what is in their best interest does not take the child's background and circumstances into account with sufficient detail and sensitivity. This paper further discusses the bureaucratic procedures that turn an individual child with individual interests into a judicial and generalized prototype that appears to have the same interests as the immigration authorities. Thus the combination of a culture‐blind and context‐free consideration of an abstract child's best interests primarily serves to justify increasing restriction of family reunion for child migrants, and thereby serves the state's best interest at the cost of the individual child.
Unsettling the ‘social’ in social work: responses to asylum seeking children in Ireland
Authors: Christie Alastair 
Published: July 2003

ABSTRACTThe ‘social’ context in which social work is located is becoming increasingly unsettled by emerging patterns of mobility. Mobility is constrained for many social work service users who are trapped within disadvantaged areas, while for others it has become a forced necessity to cross national boundaries and inhabit uncertain status in their nations of destination. This article explores the responses of the social work profession to children seeking asylum in the Republic of Ireland. These children's complex needs, produced by the conditions of mobility they have encountered and by the conditions of arrival/settlement in Ireland, force social work practice to be orientated beyond the boundaries of the national welfare state. In order to explore the varied responses of the social work profession in the Republic of Ireland to asylum seeking children, three different groups of children are considered: children seeking asylum who have been separated from their parents; children who are seeking asylum with their parent(s)/family; and young Irish citizens whose asylum seeking parents are in danger of being deported. It argues that the provision of appropriate services for these children requires the development of post‐national forms of social work practice.
A multicentre, randomized, double‐blind, placebo‐controlled, 1‐year study of bupropion SR for smoking cessation
Authors: Tønnesen P. , Tonstad S. , Hjalmarson A. , Lebargy F. , Van Spiegel P. I. , Hider A. , Sweet R. , Townsend J. 
Published: July 2003

Abstract.  Tønnesen P, Tonstad S, Hjalmarson A, Lebargy F, van Spiegel PI, Hider A, Sweet R, Townsend J (Gentofte University Hospital, Gentofte, Denmark; Clinic for Preventive Medicine, Ullevål University Hospital, Oslo, Norway; Smoking Cessation Clinic, Sahlgrenska University Hospital, Gothenburg, Sweden; Hospital Maison Blanche, Reims Cedex, France; Slotervaart Hospital, Amsterdam, The Netherlands; and GlaxoSmithKline Research and Development, Greenford, Middlesex, UK). A multicentre, randomized, double‐blind, placebo‐controlled, 1‐year study of bupropion SR for smoking cessation. J Intern Med 2003; 254: 184–192.Background.  Bupropion sustained release (bupropion SR) has been shown to increase smoking cessation success rates in the US studies.Objective.  To determine whether bupropion SR, in combination with counselling, is effective for smoking cessation in a multi‐country study.Methods.  This randomized, double‐blind, placebo‐controlled trial enrolled 707 smokers. A total of 527 received bupropion SR 300 mg daily for 7 weeks and 180 received placebo. A total of 11 clinic visits and 10 telephone contacts were scheduled, during the course of 1 year. Seven‐week and 12‐month abstinence rates were the study outcomes.Results.  Both continuous and weekly point prevalence smoking abstinence rates were significantly higher in the bupropion SR group compared with placebo. The continuous abstinence rate from weeks 4 to 7 was 46% in the bupropion SR group compared with 23% in the placebo group [odds ratio (OR) = 2.82; 95% confidence interval (CI) 1.89–4.28; P < 0.001). At month 12, the continuous abstinence rates were 21% for the bupropion SR group and 11% for the placebo group (OR = 2.19; 95% CI 1.29–3.86, P = 0.002). For most nicotine‐withdrawal symptoms small changes were measured. Adverse events were higher for the bupropion SR group compared with placebo (insomnia 24% vs. 15%; dry mouth 13% vs. 5%).Conclusion. Bupropion SR in combination with counselling increased the abstinence rate compared with placebo, and was well tolerated.
Changes in mitogen‐activated protein kinase activity occur in the maize pulvinus in response to gravistimulation and are important for the bending response
Authors: CLORE A. M. , TURNER W. S. , MORSE A. M. , WHETTEN R. W. 
Published: July 2003

ABSTRACTThe maize (Zea mays L.) pulvinus was used as a model system to study the signalling events that lead to differential growth in response to gravistimulation in plants. The pulvinus functions to return tipped plants to vertical via differential elongation of the cells on its lower side. By performing immunokinase assays using total soluble protein extracts and an antibody against mammalian ERK1, a mitogen‐activated protein kinase (MAPK)‐like activity was assayed in pulvini halves harvested at various time points after tipping. We detected a reproducible alternation of higher levels of activity occurring between the upper and lower halves of the pulvinus between 75 and 180 min after tipping, with a sustained increase in the upper half occurring at the end of the time‐course. This timing roughly corresponds to the presentation time for maize (i.e. the amount of time that the plant needs to be tipped before it is committed to bend), which occurs between 2 and 4 h. Treatment of maize stem explants with an inhibitor of MAPK activation, U0126, led to a reduction in the activity of this kinase, as well as an almost 65% reduction in bending as measured at 20 h. Rinsing out of the inhibitor resulted in recovery of both bending and kinase activity. It is possible that changes in MAPK activity in the gravistimulated pulvinus are part of a signalling cascade that may help to distinguish between minor perturbations in plant orientation and more significant and long‐term changes, and may also help to determine the direction of bending.
Whole‐tree water transport scales with sapwood capacitance in tropical forest canopy trees
Authors: MEINZER F. C. , JAMES S. A. , GOLDSTEIN G. , WOODRUFF D. 
Published: July 2003

ABSTRACTThe present study examines the manner in which several whole‐tree water transport properties scale with species‐specific variation in sapwood water storage capacity. The hypothesis that constraints on relationships between sapwood capacitance and other water relations characteristics lead to predictable scaling relationships between intrinsic capacitance and whole‐tree behaviour was investigated. Samples of sapwood from four tropical forest canopy tree species selected to represent a range of wood density, tree size and architecture, and taxonomic diversity were used to generate moisture release curves in thermocouple psychrometer chambers, from which species‐specific values of sapwood capacitance were calculated. Sapwood capacitance was then used to scale several whole‐tree water transport properties determined from measurements of upper branch and basal sap flow, branch water potential, and axial and radial movement of deuterated water (D2O) injected into the base of the trunk as a tracer. Sapwood capacitance ranged from 83 to 416 kg m−3 MPa−1 among the four species studied and was strongly correlated with minimum branch water potential, soil‐to‐branch hydraulic conductance, daily utilization of stored water, and axial and radial movement of D2O. The species‐independent scaling of several whole‐tree water transport properties with sapwood capacitance indicated that substantial convergence in plant function at multiple levels of biological organization was revealed by a simple variable related to a biophysical property of water transport tissue.
The lower cell density of leaf parenchyma in the Arabidopsis thaliana mutant lcd1‐1 is associated with increased sensitivity to ozone and virulent Pseudomonas syringae
Authors: Barth Carina , Conklin Patricia L. 
Published: July 2003

SummaryUnder optimal growth conditions (120 µmol photons m−2 sec−1 photosynthetically active radiation (PAR), 16‐h photoperiod), the recessive ozone‐sensitive Arabidopsis thaliana L. Heynh. mutant lcd1‐1 exhibits a pale phenotype compared to the wild type. Confocal and multiphoton microscopy revealed that the paleness of lcd1‐1 is because of a lower cell density in the leaf palisade parenchyma, resulting in decreased chlorophyll content. When exposed to ozone, lcd1‐1 leaves become paler and contain an increased amount of the lipid peroxidation product malondialdehyde compared to the wild type, suggesting that lcd1‐1 suffers from elevated levels of reactive oxygen species (ROS) generated in the apoplast. Infection of leaves with virulent Pseudomonas syringae reveals higher bacterial growth as well as lower pathogenesis‐related protein 1 (PR‐1) and PR‐5 expression in lcd1‐1 than in the wild type. When the wild type and lcd1‐1 are exposed to short‐term high‐light stress, leaves do not bleach in lcd1‐1 and potential activities of photosystems I (PSI) and II (PSII) decrease to a similar extent in both the genotypes, indicating that the photosynthetic apparatus is not affected by lcd1‐1 mutation. The LCD1 gene, found to contain a nonsense mutation in the mutant, has been identified. It is located at the bottom of chromosome 2 of the Arabidopsis genome. However, the function of the protein encoded by LCD1 is not yet known. We hypothesize that LCD1 plays a role in normal leaf development, and that the increased sensitivity to ozone and virulent P. syringae is a secondary effect that presumably results from the lower‐cell‐density phenotype in lcd1‐1.
Gene trapping of the Arabidopsis genome with a firefly luciferase reporter
Authors: Yamamoto Yoshiharu Y. , Tsuhara Yumi , Gohda Kazuhito , Suzuki Kumiko , Matsui Minami 
Published: July 2003

SummaryExperiments with gene‐trap vectors containing the firefly luciferase (LUC) reporter genes were carried out with the aim of analyzing functions of the Arabidopsis genome. Studies with protein fusion‐type trap vectors as well as an internal ribosome entry site (IRES)‐assisted non‐fusion‐type vector revealed that both types of vectors were suitable for gene trapping in Arabidopsis, although there were some differences in trapping efficiencies. The established trap lines were subjected to analyses for light responses, demonstrating the powerful and unique applications of a LUC‐trapping system. A systematic survey of the insertion sites of the T‐DNAs in LUC‐expressing lines revealed 12–41% gene‐trapping efficiencies depending on the vector. We demonstrate that the LUC‐trapping system provides a unique system with which to monitor temporal expression of plant genes.
Laparoscopic ablation therapy for hepatocellular carcinoma. Clinical significance of a newly developed laparoscopic sector ultrasonic probe
Authors: Noguchi Osamu , Izumi Namiki , Inoue Kazunari , Nishimura Yuki , Ueda Ken , Tsuchiya Kaoru , Hamano Kosei , Itakura Jun , Asahina Yasuhiro , Uchihara Masakatsu , Miyake Shozo 
Published: July 2003

Background:  Although a laparoscopic approach for local ablation plays an important role in treating hepatocellular carcinoma (HCC) near the liver surface, precise targeting ablation has been difficult using a conventional linear ultrasonic probe. We have recently developed a sector ultrasonic probe with a guiding tract for precisely targeting tumors.Methods:  Since 1996, 349 HCC cases have been treated with either microwave or radiofrequency ablation. A percutaneous approach was selected in 298 cases, and a laparoscopic approach was selected in 51 cases. The laparoscopic approach was selected in the cases in which serious complications due to the tumors being located on the surface or protruding from the liver, or adjacent to the gallbladder or intestine made it difficult to treat percutaneously. In the latest 21 cases, the sector ultrasonic probe was used.Results:  All the cases were safely and successfully treated by laparoscopic ablation with an exception by an extensive HCC case with portal vein tumor thrombus. Survival after the treatment by laparoscopic ablation was 95.2% in 1 year, and 82.4% in 3 years. The tumor stage was a significant prognostic factor (P < 0.0001). There was no local recurrence within 6 months of treatment in the successfully treated cases. The use of the sector probe widened indications for the laparoscopic approach for treating HCC.Conclusion:  Laparoscopic ablation can result in a satisfactory outcome in difficult‐to‐treat cases by the percutaneous approach. The newly developed sector ultrasonic probe has allowed us more therapeutic choices in the treatment of HCC.
Evaluation of the type V pit pattern in the lesions of colonic Tis and T1 cancer
Authors: Tamura Satoru , Yokoyama Yuichi , Ookawauchi Kohji , Onishi Tomoko , Onishi Saburo , Miyazaki Jun‐ichi 
Published: July 2003

Background:  The usefulness of magnifying videoendoscopic pit pattern diagnosis has been recognized in the differential diagnosis of colonic neoplasms. Also, the correspondence between lesions with a type V pit pattern and cancer has been emphasized. We evaluated the relationship between the type V pit pattern and carcinoma in situ or subdivided submucosal invading carcinomas.Methods:   During the period from May 1997 to December 2001, a total of 8696 colonoscopies were performed and 6672 colorectal lesions were detected. Colorectal lesions (47.7%; 3181/6672) were examined by videoendoscopic magnification. The type V pit pattern was divided into two groups: VI and VN. The submucosal extensions of cancers were classified as sm1, sm2 and sm3 according to the vertical level of invasion. All Tis (n = 57) and operated T1 carcinomas (n = 69) with the type V pit pattern were selected for this study.Results:  Cancer invasion with the type VI pit pattern was limited up to sm2, and the type VN pit pattern was closely related to sm3 extension in protruded type (P = 0.0005). The frequency of the appearance of the type VI pit pattern decreased and that of the type VN pit pattern increased as the invasion extended deeper into the submucosal layer in superficial‐type cancers (P < 0.0001).Conclusions:   Superficial type cancers well reflected the submucosal infiltrating cancer glands when their surface structure had a type VN pit pattern. In contrast, only 20% of sm2 cancers presented a type VN pit pattern among the protruded types.
Should scholarly societies embrace open access (or is it the kiss of death)?
Authors: Velterop Jan 
Published: July 2003

ABSTRACTIn assessing the role that organizations of scientists with publishing activities – such as scholarly societies – can or should play in furthering the science and practice in their chosen fields, they face a dilemma: should they primarily be fund‐raising organizations for other activities in their disciplines, using their publications to bring in the necessary money, or should they be promoters of efficient scholarly communication and use their publications more directly to that end – for instance, by embracing ‘open access‘.
Aggregation in Production Functions: What Applied Economists should Know
Authors: Felipe Jesus , Fisher Franklin M. 
Published: July 2003

There is no subject so old that something new cannot be said about it.(Dostoevsky)

Glendower: I can call spirits from the vasty deep Hotspur: Why, so can I, or so can any man;   But will they come when you do call for them?(Shakespeare, Henry IV, Part I, Act III, Scene I)
This paper surveys the theoretical literature on aggregation of production functions. The objective is to make neoclassical economists aware of the insurmountable aggregation problems and their implications. We refer to both the Cambridge capital controversies and the aggregation conditions. The most salient results are summarized, and the problems that economists should be aware of from incorrect aggregation are discussed. The most important conclusion is that the conditions under which a well‐behaved aggregate production function can be derived from micro production functions are so stringent that it is difficult to believe that actual economies satisfy them. Therefore, aggregate production functions do not have a sound theoretical foundation. For practical purposes this means that while generating GDP, for example, as the sum of the components of aggregate demand (or through the production or income sides of the economy) is correct, thinking of GDP as GDP=F(K, L), where K and L are aggregates of capital and labor, respectively, and F(•) is a well‐defined neoclassical function, is most likely incorrect. Likewise, thinking of aggregate investment as a well‐defined addition to ‘capital’ in production is also a mistake. The paper evaluates the standard reasons given by economists for continuing to use aggregate production functions in theoretical and applied work, and concludes that none of them provides a valid argument.
Spatial Crime Patterns and the Introduction of the UK Minimum Wage*
Authors: Hansen Kirstine , Machin Stephen 
Published: July 2003

AbstractThis paper provides an empirical evaluation of whether one can uncover a link between crime and the labour market using a research methodology that is different to that utilized in existing work. We exploit a large regulatory change that was made to the UK labour market when a national minimum wage was introduced in April 1999. This minimum wage introduction provided pay increases for quite a large number of low paid workers. From a theoretical perspective we argue that this wage boost could have altered individual incentives to participate in crime. We then go on to develop empirical tests of this hypothesis comparing spatial crime patterns, measured at police force area level, in the years before and after the introduction of the minimum wage floor. Our empirical study of area‐level crime rates before and after the minimum wage introduction uncovers a statistically significant link between changes in crime and the extent of area low pay before the minimum wage was introduced. Overall our results are in line with the notion that altering wage incentives can affect crime and therefore that there exists a link between crime and the low wage labour market.
Looking for a Needle in a Haystack? A Re‐examination of the Time Series Relationship between Teenage Employment and Minimum Wages in the United States*
Authors: Bazen Stephen , Marimoutou Velayoudom 
Published: July 2003

AbstractThe work of Card and Krueger has cast doubt on the nature of the relationship between the minimum wage and teenage employment in the United States. The earlier ‘consensus’ finding of a small but statistically significant negative effect was based on time series data whereas Card and Krueger's findings are based mainly on cross‐section data. In this article, we re‐examine the time series relationship between minimum wage and teenage employment. We find that previous models break down due to their inability to capture changes in the trend, cyclical and seasonal components of teenage employment. We propose an alternative approach in which these components are treated as stochastic components and which contains the traditional, deterministic approach as a special case. The model when estimated up to 1979 accurately predicts what happens to teenage employment subsequently, when the minimum wage was frozen after 1981 and then increased quite substantially in the early 1990s. Moreover, we find that there is a significant, negative effect of the minimum wage on teenage employment and its size has hardly changed during the 1980s and early 1990s.
Administration of C1 Inhibitor Reduces Neutrophil Activation in Patients with Sepsis
Authors: Zeerleder Sacha , Caliezi Christoph , van Mierlo Gerard , Eerenberg-Belmer Anke , Sulzer Irmela , Hack C. Erik , Wuillemin Walter A. 
Published: July 2003

ABSTRACTForty patients with severe sepsis or septic shock recently received C1 inhibitor. In the present study we studied the effect of C1 inhibitor therapy on circulating elastase-α1-antitrypsin complex (EA) and lactoferrin (LF) levels in these patients to gain further insight about agonists involved in the activation of neutrophils in human sepsis. Elevated levels of EA and LF were found in 65 and 85% of the septic patients, respectively. Patients with elevated EA levels had higher organ dysfunction scores, higher levels of cytokines, and higher levels of complement activation products than patients with normal EA levels. C1 inhibitor therapy reduced EA as well as complement activation and IL-8 release in the patients with elevated EA on admission. We conclude that neutrophil activation in human sepsis correlates with the severity of organ dysfunction and involves complement and interleukin-8 as agonists. The effect of C1 inhibitor therapy on neutrophils may provide an explanation for the beneficial, although mild, effects of this treatment on organ dysfunction in sepsis.