bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Theory of the Low‐Temperature Galvanomagnetic Effects in Semiconductors in Strong Electric Fields
Authors: Kachlishvili Z. S.
Published: July 2007

Galvanomagnetic effects have been studied by using the Boltzmann kinetic equation, when the energy of hot carriers is scattered on acoustic phonons and the momentum on statical defects. Calculations are carried out for any angle between the directions of the electric and magnetic field in the approximation of a parabolic law of dispersion and a scalar effective mass. General expressions of the galvanomagnetic characteristics were obtained both under specified current conditions and under specified electric field conditions.
Etude de la transition „Low Spin”︁‐„High Spin”︁ dans les complexes octaédriques d'ion de transition
Authors: Wajnflasz J.
Published: July 2007

Certains complexes hexacoordonnés d'ion de transition 3d présentent une variation anormale du nombre effectif de magnétons de Bohr avec la température. Ces complexes possèdent deux états d'équilibre stable caractérisés simultanément par des rayons ioniques distincts et par des niveaux fondamentaux distants de quelques centaines de degrés Kelvin, qui appartiennent à des représentations différents. Les champs cristallins, associés à ces deux états d'équilibre, sont de part et d'Autre de Δπ, pour lequel les énergies correspondantes aux deux représentations sont égales. Un modèle d'Ising, faisant intervenir une interaction entre ions de transition voisins, permet et de rendre compte des différents comportements magnétiques de ces complexes, et de délimiter un domaine d'existence d'une transition du premier ordre entre les états „low spin”︁ et „high spin”︁.
Two‐Photon Spectroscopy in CsI and CsBr
Authors: Fröhlich D. , Staginnus B. , Onodera Y.
Published: July 2007

Two‐photon measurements with polarized light on CsI and CsBr are reported. A three‐band model is derived, which describes the observed polarization dependence of the two‐photon absorption for CsI.
Concentration Dependence of Internal Friction in AlMg Alloy
Authors: Belson J. , Lemercier D. , Moser P. , Vigier P.
Published: July 2007

An internal friction peak in a series of Al‐Mg alloys containing up to 12.1 wt% Mg has been studied at torsional frequencies in the range 0.4 to 98 Hz. The temperature at which the maximum occurred was found to vary according to the Arrhenius equation with an activation energy of 1.4 eV. The peak height was found to be proportional to C C where CAl and CMg are the atomic concentrations of Al and Mg, respectively. The peak as measured after slow furnace cooling, at 0.4 Hz, was displaced to lower temperatures as a result of quenching. The magnitude of this displacement appeared to increase with increasing Mg concentration. – The results, coupled with those of complementary electron microscopy and X‐ray lattice parameter studies, substantiate previous interpretation of the peak in 5 to 7% Mg alloys at ≈ 1 Hz as being due to Zener reordering.
Some features of the transverse thermomagnetic effect in bismuth
Authors: Gitsu D. V. , Muntyanu F. M. , Fedorko A. S.
Published: July 2007

The transverse Nernst‐Ettingshausen (N‐E) effect in Bi samples with different crystallographic orientation is discussed. It is found that in samples in which the temperature gradient is directed along one of the basic crystallographic directions (bisector, C2 or C3) and a non‐zero component of the magnetic field along the C2‐axis (which is assumed to be the X‐axis) is present, the value comprises mixed even terms. It is shown that the conditions for even terms in transverse N‐E effect are identical with those for odd terms in longitudinal N‐E effect [2].
Evaluation of model compounds–polypropylene film interactions by Fourier transformed infrared spectroscopy (FTIR) method
Authors: Safa Laurent , Zaki Oussama , Leprince Yamin , Feigenbaum Alexandre
Published: July 2007

The interactions of methyl esters, methyl ketones and aldehyde compounds with polypropylene (PP) film were investigated. PP film, placed on a glass vial, was immersed in aqueous solution containing a model flavour compound. After a determined time at 45°C, the PP film was analysed by Fourier transform infrared spectroscopy (FTIR), allowing us to follow the speed of sorption and to quantify its relative rate.

  For PP films, we observed that the sorption strongly depended on the structure of sorbed molecules. For each functional group of flavour compounds, the sorption increased as the carbon chain number increased. A linear chain of 12–14 carbons favours the sorption more than a linear chain of eight carbons.

  Concerning functions, the rate of sorption usually decreases from esters to ketones and to aldehydes.

  High sorption was observed for flavour compounds with a low difference of solubility parameter (SP) value between the film and flavour [(δpolymer − δflavour)2 value]. Furthermore, by using the proposed thermodynamic affinity concept, represented as the contribution of three interactive molecular forces [dispersion (dd), polar (dp) and hydrogen bonding (dh)] between two SP values of film and flavour, packaging materials with high flavour preservation against sorption can be designed.

  We have a good correlation between the kinetic sorption by FTIR and the SP concept. Copyright © 2007 John Wiley & Sons, Ltd.
Virtual surgery simulation for medical training using multi‐resolution organ models
Authors: Kim Jung , Choi Changmok , De Suvranu , Srinivasan Mandayam A.
Published: July 2007

Background

Real‐time simulation of organ deformation is one of the biggest challenges in virtual surgery, due to the conflicting requirements of real‐time interactivity and simulation realism. In this paper we propose a method to overcome this challenge by introducing a multi‐resolution modelling technique.

Methods

In our approach a reasonably coarse global model is locally enhanced, using a mesh subdivision and smoothing algorithm. The global model is based on a discretization of the boundary integral representation of three‐dimensional deformable objects. Local refinements are provided at the tool‐tissue interaction region by a local subdivision technique.

Results

As an example, we have developed a deformable human kidney model generated from the Visible Human Dataset, with tissue properties determined fromin vivoanimal experiments. A mixed reality laparoscopic surgical training system has been developed, using an abdominal mannequin and force feedback devices.

Conclusions

The use of precomputation and structural re‐analysis techniques results in a very rapid computation procedure. Validation of the simulator is in progress. Copyright © 2007 John Wiley & Sons, Ltd.
An online active set strategy to overcome the limitations of explicit MPC
Authors: Ferreau H. J. , Bock H. G. , Diehl M.
Published: July 2007

Nearly all algorithms for linear model predictive control (MPC) either rely on the solution of convex quadratic programs (QPs) in real time, or on an explicit precalculation of this solution for all possible problem instances. In this paper, we present an online active set strategy for the fast solution of parametric QPs arising in MPC. This strategy exploits solution information of the previous QP under the assumption that the active set does not change much from one QP to the next. Furthermore, we present a modification where the CPU time is limited in order to make it suitable for strict real‐time applications. Its performance is demonstrated with a challenging test example comprising 240 variables and 1191 inequalities, which depends on 57 parameters and is prohibitive for explicit MPC approaches. In this example, our strategy allows CPU times of well below 100 ms per QP and was about one order of magnitude faster than a standard active set QP solver. Copyright © 2007 John Wiley & Sons, Ltd.
Evaluation of environmental attitudes: Analysis and results of a scale applied to university students
Authors: Fernández‐Manzanal Rosario , Rodríguez‐Barreiro Luis , Carrasquer Jose
Published: July 2007

Over the last few decades, environmental work has increased significantly. An important part of this has to do with attitudes. This research presents the design and validation of an environmental attitudes scale aimed at university students. Detailed information on development and validation of the scale is provided. Similarly, it presents the data derived from its application to a specimen group of students. The number of students involved in the whole research is 952. The results of the work show that a certain level of worry exists among the students regarding environmental problems, which is apparent in the need to increase environmental education and research. Some differences in environmental attitudes were also found between first year students and final year students and male and female students. These results lead us to insist on the importance of bringing about changes in the curriculum to increase environmentalism in the university. © 2007 Wiley Periodicals, Inc. Sci. Ed 91:988–1009, 2007
Item readability and science achievement in TIMSS 2003 in South Africa
Authors: Dempster Edith R. , Reddy Vijay
Published: July 2007

This study investigated the relationship between readability of 73 text‐only multiple‐choice questions from Trends in International Mathematics and Science Study (TIMSS) 2003 and performance of two groups of South African learners: those with limited English‐language proficiency (learners attending African schools) and those with better English‐language proficiency (learners attending non‐African schools). Both groups were exposed to the same intended curriculum, but differed with respect to the quality of teaching they received, the availability of resources, and the level of functionality of their schools. Learners from non‐African schools performed significantly better than learners from African schools. Three readability factors (sentence complexity, unfamiliar words, and long words) were analyzed. High sentence complexity resulted in random guessing in non‐African schools, and favoring an incorrect answer in African schools. Some TIMSS items have complex wording, with numerous prepositional phrases and clauses, and unclear questions. Recommendations for maximum readability and comprehensibility were not met, and these items are therefore invalid for learners with limited English‐language proficiency. Learners employ a range of strategies in attempting to answer questions that they do not understand. Overall, though, poor readability of TIMSS items does not fully account for South African learners' poor performance in TIMSS. © 2007 Wiley Periodicals, Inc. Sci. Ed 91:906–925. 2007
Sociocultural influences on science education: Innovation for contemporary times
Authors: Carter Lyn
Published: July 2007

This paper reviews the significant sociocultural literatures on science studies, cultural diversity, and sustainability science to develop theoretical perspectives for science education more suitable to the challenges of contemporaneity. While the influences of science studies and cultural diversity are not uncommon within the science education literature on innovation, the difference here is the inclusion of the newer field of sustainability science. These threads are drawn are together to help formulate a view of science education that contributes to the ongoing discussion of what it could be in the 21st century. Finally, a science unit in a preservice teacher education course is then described, which aims to engage, inform, and empower beginning teachers in ways that tackle the challenges of contemporaneity. © 2007 Wiley Periodicals, Inc. Sci Ed 92:165–181, 2008
Interim treatment selection using the normal approximation approach in clinical trials
Authors: Shun Zhenming , Lan K. K. Gordon , Soo Yuhwen
Published: July 2007

We consider a study starting with two treatment groups and a control group with a planned interim analysis. The inferior treatment group will be dropped after the interim analysis, and only the winning treatment and the control will continue to the end of the study. This ‘Two‐Stage Winner Design’ is based on the concepts of multiple comparison, adaptive design, and winner selection. In a study with such a design, there is less multiplicity, but more adaptability if the interim selection is performed at an early stage. If the interim selection is performed close to the end of the study, the situation becomes the conventional multiple comparison where Dunnett's method may be applied.

The unconditional distribution of the final test statistic from the ‘winner’ treatment is no longer normal, the exact distribution of which is provided in this paper, but numerical integration is needed for its calculation. To avoid complex computations, we propose a normal approximation approach to calculate the type I error, the power, the point estimate, and the confidence intervals. Due
to the well understood and attractive properties of the normal distribution, the ‘Winner Design’ can be easily planned and adequately executed, which is demonstrated by an example. We also provide detailed discussion on how the proposed design should be practically implemented by optimizing the timing of the interim look and the probability of winner selection. Copyright © 2007 John Wiley & Sons, Ltd.
Treatment with dexamethasone and vitamin D3 attenuates neuroinflammatory age‐related changes in rat hippocampus
Authors: Moore Michelle , Piazza Alessia , Nolan Yvonne , Lynch Marina A.
Published: July 2007

Among the changes which occur in the brain with age is an increase in hippocampal concentration of proinflammatory cytokines like interleukin‐1β (IL‐1β) and an increase in IL‐1β‐induced signaling. Here we demonstrate that the increase in IL‐1β concentration is accompanied by an increase in expression of IL‐1 type I receptor (IL‐1RI) and an age‐related increase in microglial activation, as shown by increased expression of the cell surface marker, major histocompatibility complex II (MHCII) and increased MHCII staining. The evidence indicates that these age‐related changes were abrogated in hippocampus of aged rats treated with dexamethasone and vitamin D3. Similarly, the age‐related increases in activation of the stress‐activated protein kinase, c‐Jun N‐terminal kinase (JNK), as well as caspase‐3 and PARP were all attenuated in hippocampal tissue prepared from rats that received dexamethasone and vitamin D3. The data indicate that dexamethasone and vitamin D3 ameliorated the age‐related increase in IFNγ and suggest that IFNγ may be the trigger leading to microglial activation, since it increases MHCII mRNA and IL‐1β release from cultured glia. In parallel with its ability to decrease microglial activation in vivo, we report that treatment of cultured glia with dexamethasone and vitamin D3 blocked the lipopolysaccharide increased MHCII mRNA and IL‐1β concentration, while the IL‐1β‐induced increases in activation of JNK and caspase 3 in cultured neurons were also reversed by treatment with dexamethasone and vitamin D3. The data suggest that the antiinflammatory effect of dexamethasone and vitamin D3 derives from their ability to downreguate microglial activation. Synapse 61:851–861, 2007. © 2007 Wiley‐Liss, Inc.
Downregulation of κ‐opioid receptors in basolateral amygdala and septum of rats withdrawn for 14 days from an escalating dose “binge” cocaine administration paradigm
Authors: Bailey Alexis , Gianotti Robert , Ho Ann , Kreek Mary J.
Published: July 2007

There is evidence showing that the opioid systems play an important role in cocaine addiction; fewer studies have examined their roles in cocaine withdrawal. This study was conducted to determine whether cocaine or chronic withdrawal from cocaine alters the receptor component of the κ‐opioid system. Male Fischer rats were injected with saline or cocaine (3 × 15 mg/kg/day for 4 days, 3 × 20 mg/kg/day for 4 days, 3 × 25 mg/kg/day for 4 days, and 3 × 30 mg/kg/day for 2 days), three times daily at 1‐h intervals in an escalating dose paradigm for 14 days. Identically treated rats were withdrawn from cocaine or saline for 14 days. We performed quantitative autoradiographic mapping of κ‐opioid receptors (KOP‐r) in the brains of rats treated with this escalating dose “binge” cocaine administration paradigm and of rats withdrawn from cocaine for 14 days. A significant condition (chronic/withdrawal) effect was shown across all regions analyzed. A significant increase in [3H]CI‐977 binding to KOP‐r was detected in the septum of rats treated with an escalating dose binge cocaine administration paradigm and killed 30 min after the last cocaine injection. In contrast, there was a decrease in KOP‐r binding in the septum and the basolateral amygdala of rats withdrawn for 14 days from chronic escalating dose binge cocaine administration, compared to rats at the end of 14 days chronic escalating dose cocaine administration. These results reconfirm and extend that KOP‐r undergoes upregulation in response to chronic binge cocaine administration here, with an escalating dose. The observed lowering in KOP‐r binding, which was shown in two brain regions of cocaine withdrawn animals, might contribute to the persistent dysphoria reported a long time after the discontinuation of the drug. Synapse 61:820–826, 2007. © 2007 Wiley‐Liss, Inc.
Plant sterol-enriched milk tea decreases blood cholesterol concentrations in Chinese adults: a randomised controlled trial
Authors: Li Nicole Y. , Li Keji , Qi Zhi , Demonty Isabelle , Gordon Michelle , Francis Lesley , Molhuizen Henri O. F. , Neal Bruce C.
Published: July 2007

The cholesterol-lowering effects of plant sterols in a format suitable for use in China have not previously been investigated. We conducted the study to quantify in adult Chinese the effects on blood lipid concentrations of a plant sterol-enriched milk tea powder. The study was a double-blind, randomised trial in which 309 participants were randomised to receive daily 2·3 or 1·5 g plant sterol supplementation or placebo for 5 weeks. The milk tea was consumed with the two fattiest meals of the day with half the assigned daily dose taken on each occasion. Fasting venous blood samples were collected before commencement and upon completion of randomised treatment. The mean age of study participants was 44 years, 62 % were female and 62 % had a history of hypercholesterolaemia. Baseline mean total cholesterol was 5·5 mmol/l and LDL-cholesterol was 3·2 mmol/l. Compared with placebo, the 2·3 g/d plant sterol dose reduced total cholesterol by 0·25 (95 % CI 0·07, 0·43) mmol/l (P = 0·01) and the 1·5 g/d dose by 0·23 (95 % CI 0·06, 0·41) mmol/l (P = 0·01). For LDL-cholesterol the corresponding reductions were 0·17 (95 % CI 0·00, 0·35) mmol/l (P = 0·06) and 0·15 (95 % CI − 0·02, 0·32) mmol/l (P = 0·08). For neither outcome was there evidence of differences between the effects of the two doses (both P values >0·4). In conclusion, the consumption of plant sterol-enriched milk tea decreased cholesterol concentrations although to a lesser extent than was anticipated. The reason for reduced efficacy is unclear but may be attributable to the novel food format used or the Chinese population studied.
Mechanism involved in genistein activation of insulin-like growth factor 1 receptor expression in human breast cancer cells
Authors: Chen Wen-Fang , Gao Quan-Gui , Wong Man-Sau
Published: July 2007

Our previous studies have shown that genistein can enhance the insulin-like growth factor (IGF)-1 receptor signalling pathway via an oestrogen receptor (ER) in human breast cancer MCF-7 cells. The present study aims to investigate how genistein regulates IGF-1 receptor expression in human MCF-7 cells. Genistein at 1 μm stimulated the growth of MCF-7 cells and this effect could be completely blocked by the IGF-1 receptor antagonist JB-1, suggesting that IGF-1 receptor is essential for mediating the proliferative effects of genistein in MCF-7 cells. Genistein increased IGF-1 receptor promoter activity. This effect could be completely abolished by co-treatment of MCF-7 cells with ICI 182,780 (10− 6 m). Genistein increased IGF-1 receptor gene expression and this effect could be completely blocked by the IGF-1 receptor antagonist JB-1. Co-treatment of MCF-7 cells with cycloheximide (5 μg/ml) completely blocked the induction of IGF-1 receptor protein and mRNA expression by genistein. The results indicated that the induction of IGF-1 receptor promoter activity by genistein required the action of ER while the stimulatory actions of genistein on IGF-1 receptor expression required the activity of the IGF-1 receptor and de novo protein synthesis. These data provide evidence to support the hypothesis that the inductive effects of genistein on IGF-1 receptor expression require the cross-talk between IGF-1 receptor and the ER-dependent pathways.
Vitamin C deficiency in weanling guinea pigs: differential expression of oxidative stress and DNA repair in liver and brain
Authors: Lykkesfeldt Jens , Perez Trueba Gilberto , Poulsen Henrik E. , Christen Stephan
Published: July 2007

Neonates are particularly susceptible to malnutrition due to their limited reserves of micronutrients and their rapid growth. In the present study, we examined the effect of vitamin C deficiency on markers of oxidative stress in plasma, liver and brain of weanling guinea pigs. Vitamin C deficiency caused rapid and significant depletion of ascorbate (P < 0·001), tocopherols (P < 0·001) and glutathione (P < 0·001), and a decrease in superoxide dismutase activity (P = 0·005) in the liver, while protein oxidation was significantly increased (P = 0·011). No changes in lipid oxidation or oxidatively damaged DNA were observed in this tissue. In the brain, the pattern was markedly different. Of the measured antioxidants, only ascorbate was significantly depleted (P < 0·001), but in contrast to the liver, ascorbate oxidation (P = 0·034), lipid oxidation (P < 0·001), DNA oxidation (P = 0·13) and DNA incision repair (P = 0·014) were all increased, while protein oxidation decreased (P = 0·003). The results show that the selective preservation of brain ascorbate and induction of DNA repair in vitamin C-deficient weanling guinea pigs is not sufficient to prevent oxidative damage. Vitamin C deficiency may therefore be particularly adverse during the neonatal period.
Alternative strategies for activation of the natural lactoperoxidase system in cows' milk: trials in Tanzania
Authors: Fweja Leonard WT , Lewis Michael J , Grandison Alistair S
Published: July 2007

Thiocyanate content and lactoperoxidase activity of individual cow's milk of different breeds were determined, and the effects of different lactoperoxidase system (LP-s) activation strategies were compared. Lactoperoxidase activity varied significantly between Friesian and both Ayrshire and Tanzania Short Horn Zebu (TSHZ), but differences between Ayrshire and TSHZ were not significant. There was no significant variation in SCN− content between breeds. The LP-s was activated using three strategies based on SCN−: namely; equal concentrations of SCN− and H2O2 (7:7, 10:10, 15:15 mg/l), excess SCN− concentrations (15:10, 20:10, 25:10 mg SCN−:H2O2/l), and excess H2O2 concentrations (10:15, 10:20, 10:25 mg SCN−:H2O2/l), plus a fourth strategy based on I− (15:15 mg I−:H2O2/l). The keeping quality (KQ) was assessed using pH, titratable acidity, clot on boiling and alcohol stability tests. All activation strategies enhanced the shelf life of milk (typically increasing KQ from around 10 to around 20 h), but it was clear that the effectiveness of the LP-s depends on the type and concentrations of the activators of the system. The LP-s activated using I− as an electron donor was more effective than the LP-s activated using SCN− as an electron donor, increasing the KQ by a further 6–8 h compared with SCN−.
The effect of probiotic fermented milk and inulin on the functions and microecology of the intestine
Authors: Sairanen Ulla , Piirainen Laura , Gråsten Soile , Tompuri Tuomo , Mättö Jaana , Saarela Maria , Korpela Riitta
Published: July 2007

We investigated the effects of a probiotic fermented milk and inulin on gastrointestinal function and microecology. The study was double-blinded and comprised 66 healthy adults (22 male, 44 female), mean age 40 years (range, 22–60 years). After a 12-d baseline period the subjects were randomized to consume, for 3 weeks, 3×200 ml daily of either (1) a fermented milk with probiotics (Bifidobacterium longumBB536,Bifidobacteriumspp. 420 andLactobacillus acidophilus145), (2) a fermented milk with the same probiotics plus 4 g inulin, or (3) a control fermented milk. During the last 7 d of the baseline and the intervention periods, the subjects kept a record of their defaecation frequency and gastrointestinal symptoms, and collected all their faeces. Intestinal transit time, stool weight and faecal enzyme activities were measured. Thirty-nine subjects were randomized to give faecal samples for analysis of pH and microbes, including lactobacilli, bifidobacteria, coliforms,Escherichia coli,BacteroidesandClostridium perfringens. Consumption of fermented milk with probiotics or with probiotics and inulin increased the faecal number of lactobacilli (P=0·009,P=0·003) and bifidobacteria (P=0·046,P=0·038) compared with the baseline. Compared with the control fermented milk, both active products increased lactobacilli (P=0·005, ANCOVA). Subjects consuming fermented milk with probiotics and inulin suffered from gastrointestinal symptoms, especially flatulence, more than the others (P<0·001). In conclusion, the probiotic fermented milk product had a positive effect by increasing the number of lactobacilli and bifidobacteria in the colon. Inulin did not alter this effect but it increased gastrointestinal symptoms.
Immediate post-operative vocal changes in patients using laryngeal mask airway versus endotracheal tube
Authors: Hamdan A-L , Kanazi G , Rameh C , Rifai H , Sibai A
Published: July 2007

Objective and hypothesis:

(1) To examine the vocal symptoms and acoustic changes perceived in the short period immediately after laryngeal mask airway, and (2) to compare these findings in patients using laryngeal mask airway and endotracheal tube.

Materials and methods:

A total of 27 patients were enrolled. They were evaluated pre-operatively and then at 2 and 24 hours post-operatively. Patients were divided into two subgroups, laryngeal mask airway and endotracheal tube. Patients were asked about the presence or absence of the following: hoarseness, vocal fatigue, loss of voice, throat-clearing sensation, globus pharyngeus and throat pain. Patients then underwent acoustic analysis of their voice, measuring the average fundamental frequency, relative average perturbation, shimmer, noise to harmony ratio, voice turbulence index, habitual pitch and maximum phonation time.

Results:

In the laryngeal mask airway group, there was an increase in the incidence of all vocal symptoms two hours post-operatively, except for globus pharyngeus. The increase was statistically significant for vocal fatigue, loss of voice and throat pain. All the symptoms had reverted back to a normal baseline level by 24 hours. There was a decrease in the maximum phonation time and habitual pitch, with an increase in all the perturbation parameters, two hours post-operatively. At 24 hours, an increase was still present for shimmer, noise to harmony ratio and voice turbulence index. The maximum phonation time and habitual pitch reverted back to normal values.

In the endotracheal tube group, there was a significant increase two hours post-operatively in the incidence of hoarseness, loss of voice and throat pain. At 24 hours, all the symptoms reverted to baseline, except for vocal fatigue and throat pain. Two hours post-operatively, there was a significant decrease in maximum phonation time and an increase in all other parameters (however, the latter was significant only for relative average perturbation and noise to harmony ratio). At 24 hours, there was a significant increase in the maximum phonation time and a persistent (but statistically insignificant) increase in the average fundamental frequency, habitual pitch, noise to harmony ratio and voice turbulence index.

At two hours, there was more loss of voice and vocal fatigue in the laryngeal mask airway group, compared with the endotracheal tube group. At 24 hours, these symptoms were comparable in both groups. Comparing changes in acoustic parameters to baseline values in both groups, there were no statistically significant changes.

Conclusion:

Shortly after reversal of anaesthesia, laryngeal symptoms following laryngeal mask airway are no less significant than those experienced following endotracheal tube anaesthesia. Both methods can be regarded as nontraumatic, in view of the lack of significant vocal symptoms and acoustic changes 24 hours after anaesthesia.
The psychological evaluation of Samaritan kidney donors: a systematic review
Authors: Kranenburg L. , Zuidema W. , Erdman R. , Weimar W. , Passchier J. , Busschbach J.
Published: July 2007

Background

Living kidney donation to a loved one has become common practice. Another type of living donation that is becoming more acceptable to the transplant community is ‘Samaritan donation’. Samaritan kidney donors are willing to donate to patients they do not know. Until recently there has been great reluctance to accept the offers of Samaritan donors because it was feared that these donors might be mentally unstable.

Method

The purpose of this article is to review the literature about the psychological evaluation of potential Samaritan kidney donors for donor suitability. We have performed a systematic literature search in Pubmed, ISI Web of Science and PsycINFO. We compare and discuss how each study approaches the question about Samaritan donor selection. In addition, we have also screened the studies for reports of rejections of Samaritan donors on psychological grounds.

Results

We have found five articles that at least in some detail describe the evaluation of potential Samaritan donors. For all five articles found, a consultation with either a psychiatrist or a psychologist formed a standard part of the donor evaluation procedure. This evaluation consisted of an interview, and in most instances, additional psychometric testing. According to the articles found, the two major criteria for donor rejection were psychopathology/psychological instability and motivational issues. Three studies reported on the rejection of potential donors on psychological grounds.

Conclusions

The evaluation of Samaritan kidney donors is a developing field in clinical medicine. Given the relatively low incidence of these types of donations, we recommend the exchange of experience between centres that run a Samaritan donor programme, in order to improve donor evaluation criteria.
Relativistic plasma control for single attosecond pulse generation: Theory, simulations, and structure of the pulse
Authors: Baeva T. , Gordienko S. , Pukhov A.
Published: July 2007

The method of relativistic plasma control (RPC) for generation of single (sub-) attosecond pulses based on high harmonic generation at plasma surface is presented. Use is made of the concept of apparent reflection point (ARP), introduced for the sake of analytical treatment of the plasma dynamics. We show theoretically and numerically that managing the laser polarisation the ARP dynamics can be efficiently controlled and a single ultra-short pulse can be extracted out of the short pulse train generated by a multi-cycle driver. For the sake of future applications the structure of the pulse is studied analytically and numerically by particle-in-cell simulations.
Review of ultrafast ion acceleration experiments in laser plasma at Max Born Institute
Authors: Nickles P.V. , Ter-Avetisyan S. , Schnürer M. , Sokollik T. , Sandner W. , Schreiber J. , Hilscher D. , Jahnke U. , Andreev A. , Tikhonchuk V.
Published: July 2007

New perspectives have been opened up in the field of laser–matter interactions due to recent advances in laser technology, leading to laser systems of high contrast and extreme intensity values, where the frontier of maximum intensity is pushed now to about 1022 W/cm2. Many striking phenomena such as laser-acceleration of electrons up to the GeV level, fast moving ions with kinetic energies of several 10s of MeV, as well as nuclear physics experiments have already actuated a broad variety of theoretical as well as experimental studies. Also highly relativistic effects like laser induced electron-positron pair production are under discussion. All these activities have considerably stimulated the progress in understanding the underlying physical processes and possible applications. This article reviews recent advances in the experimental techniques as well as the associated plasma dynamics studies at relativistic intensities performed at the Max-Born-Institute (MBI). Interactions of a laser pulse at intensities above 1019 W/cm2 with water- and heavy-water droplets, as well as, with thin foils are discussed. Rear and front side acceleration mechanisms, particle dynamics inside the dense target, proton source characteristics, strong modulations in proton and deuteron emission spectra, and finally generation of quasi-monoenergetic deuteron bursts are the topics covered in the article.
WHY ARE THE WAGES OF JOB STAYERS PROCYCLICAL?
Authors: SHIN DONGGYUN , SHIN KWANHO
Published: July 2007

This paper explains how real wages are procyclical for those who stay with the same employer. On the basis of the Panel Study of Income Dynamics data for the period from 1974–1975 to 1990–1991, we find that the substantial wage procyclicality among job stayers is mostly accounted for by large wage adjustments during the period when the unemployment rate reaches a historical minimum level from the start of the employee's current job. This finding explains how the real wages of job stayers behave asymmetrically over the cycle and more importantly how the evidence of stayers' great wage procyclicality accords with the theoretical prediction of implicit contracts that stresses costless mobility.
POLICY INTERACTION, LEARNING, AND THE FISCAL THEORY OF PRICES
Authors: EVANS GEORGE W. , HONKAPOHJA SEPPO
Published: July 2007

We investigate both the rational explosive inflation paths studied by McCallum (2001), and the classification of fiscal and monetary policies proposed by Leeper (1991), for stability under least squares (LS) learning of the rational expectations equilibria (REE). Our first result is that the explosive fiscalist REE is not locally stable under LS learning. In contrast, in Leeper's setting, there are policy regimes for which the fiscalist solution, in which fiscal variables affect the price level, can be a locally stable outcome under LS learning. However, for other policy regimes the monetarist solution is, instead, the locally stable REE.
Architectural evolution of the Nojima fault and identification of the activated slip layer by Kobe earthquake
Authors: Tanaka Hidemi , Omura Kentaro , Matsuda Tatsuo , Ikeda Ryuji , Kobayashi Kenta , Murakami Masaki , Shimada Koji
Published: July 2007

Evolutionary history of Nojima Fault zone is clarified by comprehensive examinations of petrological, geophysical, and geochemical characterizations on a fault zone in deep‐drilled core penetrating the Nojima Fault. On the basis of the results, we reconstruct a whole depth profile of the architecture of the Nojima Fault and identify the primal slip layer activated by 1995 Kobe earthquake. The deepest part (8‐ to 12‐km depth) of the fault zone is composed of thin slip layers of pseudotachylite (5 to 10 mm thick each, 10 cm in total). Middle depth (4‐ to 8‐km depth) of the fault zone is composed of fault core (6 to 10 m thick), surrounded by thick (100 m thick) damage zone, characterized by zeolite precipitation. The shallow part of the fault zone (1‐ to 4‐km depth) is composed of distributed narrow shear zones, which are characterized by combination of thin (0.5 cm thick each, 10 cm in total) ultracataclasite layers at the core of shear zones, surrounded by thicker (1 to 3 m thick) damage zones associated with carbonate precipitation. An extremely thin ultracataclasite layer (7 mm thick), activated by the 1995 Kobe earthquake, is clearly identified from numerous past slip layers, overprinting one of the shear zones, as evidenced by conspicuous geological and geophysical anomalies. The Nojima Fault zone was 10 to 100 times thicker at middle depth than that of shallower and deeper depths. The thickening would be explained as a combination of physical and chemical effects as follows. (1) Thickening of “fault core” at middle depth would be attributed to normal stress dependence on thickness of the shear zone and (2) an extreme thickening of “damage zone” in middle depth of the crust would result from the weakening of the fault zone due to super hydrostatic fluid pressure at middle depths. The high fluid pressure would result from faster sealing with low‐temperature carbonate at the shallower fault zone.
Idealized three‐dimensional modeling of seasonal variation in the Alaska Coastal Current
Authors: Williams William J. , Weingartner Thomas J. , Hermann Albert J.
Published: July 2007

Seasonal variation of the buoyancy‐ and downwelling‐wind‐forced Alaska Coastal Current (ACC) and the fate of freshwater contained in it is considered using idealized analytical and numerical models of the ACC formed from a half‐line source of buoyant inflow. The coastal current initially develops two‐dimensionally but becomes three‐dimensional from a balance between coastal influx of buoyancy and its downstream transport, which leads to a coastal current depth limit Hmax = ()1/2, where x is along‐shelf distance, Q is the line source strength for unit length, f is the Coriolis frequency, and g′ is the reduced gravity of the buoyant inflow. This limit is unchanged under downwelling wind stress and is reached on timescales of less than 1 month for the ACC. The coastal current width is roughly constant in x and increases in time at the same rate as the two‐dimensional solution. Imposition of a downwelling wind stress τ results in an approximate balance among wind stress and along‐ and cross‐shelf momentum advection so that the current width is reduced to Ywind ≈ LD ()1/2, where LD is the Rossby radius of deformation, τ is the wind stress and ρ0 is a reference density. Waves/eddying motions eventually grow in the half‐line source coastal current with wavelengths proportional to the coastal current width and with a downstream phase speed slower than the maximum current speed. These features cause an offshore flux of buoyant water, a broader coastal current, and further accumulation of buoyancy on the shelf. Increasing downwelling wind stress reduces the effects of the instabilities. Continual accumulation of buoyancy on the shelf occurs during all model runs but is nearly absent under maximum winter downwelling wind stress. It is suggested that freshwater accumulation on the shelf during spring, summer, and fall may be largely lost downstream during winter.
Carbon cycling in large lakes of the world: A synthesis of production, burial, and lake‐atmosphere exchange estimates
Authors: Alin Simone R. , Johnson Thomas C.
Published: July 2007

We present a synthesis of available estimates of primary production, organic carbon burial, and lake‐atmosphere carbon dioxide exchange data for large lakes of the world. All three fluxes showed significant relationships with latitude and related climate variables, with lower production, higher evasion of carbon dioxide, and higher burial efficiency at higher latitudes. There was no relationship between raw organic carbon mass accumulation rates and latitude. Our estimates suggest that an order of magnitude more carbon is lost to the atmosphere by evasion than is buried in sediments at a global scale, with total global production, evasion, and burial fluxes of approximately 250, 90, and 7 Tg C yr−1. Finally, the data suggest a trend from autotrophy in low‐latitude large lakes to heterotrophy and increasing reliance on allochthonous carbon sources in lakes at higher latitudes.
Sclerochronology and geochemical variation in limpet shells (Patella vulgata): A new archive to reconstruct coastal sea surface temperature
Authors: Fenger Tracy , Surge Donna , Schöne Bernd , Milner Nicky
Published: July 2007

Climate archives contained in shells of the European limpet, Patella vulgata, accumulated in archaeological deposits can potentially provide much needed information about Holocene environmental change in midlatitude coastal areas. Before reconstructing climate information preserved in these zooarchaeological records, we studied the controls on oxygen and carbon isotope ratios (δ18O and δ13C, respectively) in modern specimens. We tested the hypothesis that P. vulgata precipitates its shell in isotopic equilibrium with the ambient water by comparing δ18OSHELL with predicted values. Predicted δ18OSHELL was constructed using observed sea surface temperature (SST) records and the equilibrium fractionation equation for calcite and water. We assumed a constant δ18OWATER value of +0.10‰ (VSMOW) based on published regional measurements. Comparison of δ18OSHELL with predicted values revealed that δ18OSHELL values were higher than expected by +1.01 ± 0.21‰. Consequently, estimated SST calculated from δ18OSHELL was 4.2 ± 2.3°C lower than observed SST. However, because of the relatively uniform offset between observed and expected δ18O, an adjustment can be made to account for this predictable vital effect. Thus past climate can be reliably reconstructed using this temperature proxy once the offset is taken into account. δ13C values have a similar cyclicity to the δ18O variation and therefore vary seasonally. However, δ13C is slightly out of phase relative to δ18O. An overall negative shift in δ13CSHELL over the lifetime of the individual indicates a vital effect associated with ontogeny. Further study of environmental and ecological factors that influence shell δ13C is required to evaluate fully the potential of carbon isotope ratios as a useful environmental proxy.
Bifurcation of drift shells near the dayside magnetopause
Authors: Öztürk M. Kaan , Wolf R. A.
Published: July 2007

Close to the dayside magnetopause, there is a region of space where each field line has two magnetic field minima, one near each cusp. That region is located around local noon, and extends about 1–2 Re from the magnetopause. Particles that enter this region with equatorial pitch angles sufficiently close to 90° will cross the dayside not along an equatorial path, but along one of the two branches on either side of the equatorial plane. The two branches are joined again past local noon. This process of drift‐shell bifurcation (DSB) is nonadiabatic even under static conditions. Two physical mechanisms can cause this nonadiabaticity: one that is operative for nearly all magnetospheric magnetic field configurations and another that depends on a particular combination of north‐south and east‐west asymmetry in the magnetic field. This paper deals only with the first mechanism. For configurations with north‐south and east‐west symmetry, DSB changes the second invariant I of the motion by a small amount that is of the order of the gyroradius (the first invariant is intact). For near‐equatorial particles (I ≈ 0) the change can be significantly larger. Assuming north‐south and dawn‐dusk symmetry, we present general theoretical expressions for the second‐invariant jump ΔI, which can be applied to a variety of magnetic field models. The results show that ΔI is sensitively dependent on the bounce phase of the particle at the bifurcation line. The RMS value of ΔI over a bounce‐phase ensemble increases with decreasing mirror field and with increasing kinetic energy. We verify these results with test‐particle simulations using model magnetic fields.
On the dynamics of a hydrous melt layer above the transition zone
Authors: Leahy Garrett M. , Bercovici David
Published: July 2007

The “transition zone water filter” (Bercovici and Karato, 2003) model relies on the presence of a dense hydrous melt above the 410‐km discontinuity that is formed by dehydration melting as wet wadsleyite undergoes a phase change to low‐water‐solubility olivine. Recent studies suggest that, particularly in the Pacific, there is sufficient water in the transition zone for dehydration melting to occur. Here we construct a model for melt spreading and entrainment along the 410‐km discontinuity. In particular, we propose a mechanism for melt entrainment in downwelling regimes at ambient mantle temperatures. We find: (1) that this entrainment mechanism is efficient in that it does not require melt to reach subducting slabs in order to recycle most of the upwelling water; (2) that in steady state, the efficiency of entrainment does not necessitate the existence of a thick melt layer; (3) that the entrainment of hydrous, buoyant material into the transition zone significantly affects the bulk mantle flow field, thereby diminishing entrainment efficiency and allowing the melt to spread further; (4) that these interactions help to recirculate water from the entrained regions through the transition zone; and (5) that the adjustments in bulk mantle velocity due to water entrainment are characterized by a broadening of upward flow with a corresponding decrease in amplitude. Our model predicts regions of high water content in the transition zone at ambient mantle temperatures, which may contribute to seismic observations of high attenuation near slabs.
A mathematical formulation of accelerating moment release based on the stress accumulation model
Authors: Mignan A. , King G. C. P. , Bowman D.
Published: July 2007

Large earthquakes can be preceded by a period of accelerating seismic activity of moderate‐sized earthquakes. This phenomenon, usually termed accelerating moment release, has yet to be clearly understood. A new mathematical formulation of accelerating moment release is obtained from simple stress transfer considerations, following the recently proposed stress accumulation model. This model, based on the concept of elastic rebound, simulates accelerating seismicity from theoretical stress changes during an idealized seismic cycle. In this view, accelerating moment release is simply the consequence of the decrease, due to loading, of the size of a stress shadow due to a previous earthquake. We show that a power law time‐to‐failure equation can be expressed as a function of the loading rate on the fault that is going to rupture. We also show that the m value, which is the power law exponent, can be defined as m = D/3, with D a parameter that takes into account the geometrical shape of the stress lobes and the distribution of active faults. In the stress accumulation model, the power law is not due to critical processes.