bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural control of englacial drainage systems in Himalayan debris-covered glaciers
Authors: Gulley J. , Benn D.I.
Published: December 2007

Englacial cave systems were mapped using speleological techniques in three debris-covered glaciers in the Khumbu Himal, Nepal. Detailed three-dimensional mapping of the cave systems and observations of relationships with structures in the surrounding ice show conduits formed by a mechanism directly analogous to speleogenesis in limestone karst. The highest, oldest parts of all passages developed along debris-filled crevasse traces with hydraulic conductivity in the range 10–4 to 10–5ms–1. Conduits form when these hydraulically efficient pathways bridge between areas with different hydraulic potential. They then evolve by grading (through head-ward migration of nick points and vertical incision) to local base level, often the surface of supraglacial lakes. Most supraglacial lakes on Himalayan glaciers are perched above the elevation of the terminal stream, and exist for a few years before draining through englacial conduits. As a result, near-surface drainage evolution is frequently interrupted by base-level fall, and conduits may record multiple phases of incision. Conduits commonly migrate laterally during incision, undermining higher levels of the ice and encouraging collapse. Voids can be created by fluvial processes and collapse of crevassed ice. The oft-noted resemblance of the surface morphology of debris-covered glaciers to karst landscapes thus extends to the subsurface, and karst hydrology provides a framework for understanding englacial drainage.
Exact solutions to the thermomechanically coupled shallow-ice approximation: effective tools for verification
Authors: Bueler Ed , Brown Jed , Lingle Craig
Published: December 2007

We describe exact solutions to the thermomechanically coupled shallow-ice approximation in three spatial dimensions. Although artificially constructed, these solutions are very useful for testing numerical methods. In fact, they allow us to verify a finite-difference scheme, that is, to show that the results of our numerical scheme converge to the correct continuum values as the grid is refined in three dimensions. Comparison of numerical results with exact solutions has helped us to precisely quantify and understand some of the numerical errors we are making. Our verified numerical scheme shows the basal temperature spokes which arose in the EISMINT (European Ice Sheet Modelling INiTiative) II intercomparison (Payne and others, 2000). A careful analysis describes these warm spokes as numerical errors which occur when the derivative of the strain-heating term with respect to the temperature is large. On the other hand, the appearance of basal temperature spokes in a verified numerical scheme strongly suggests that they are a feature of the EISMINT II experiment F continuum problem. In fact, they are clear evidence of an unstable equilibrium point of the continuum problem. This paper is a sequel to Bueler and others (2005) which addresses exact solutions and verification in the isothermal case.
The general viscous relation for the response of ice and its implications in the reduced model for ice-sheet flow
Authors: Morland L.W.
Published: December 2007

Analyses of confined and unconfined compression combined with shear, and of biaxial stress laterally confined or unconfined, are presented for a general deviatoric viscous relation describing the response of an incompressible material. At present, numerical models for ice-sheet flow commonly adopt a very simple viscous law throughout the ice sheet, in which the deviatoric stress is coaxial with the strain rate, and the single response function depends on only one invariant, and is determined by single stress component tests which cannot verify the validity of the simplification. The analysis presented here is concerned with two-stress-component experimental configurations which could determine the general quadratic form of a viscous relation, with two response functions depending on two invariants. It is shown that the two combined compression and shear tests can also check the consistency of a viscous fluid assumption, but not so the biaxial stress tests. Each test allows a direct assessment of the significance of the quadratic term. It is then shown that a significant quadratic term changes the relative stress magnitudes in the commonly adopted reduced model for ice-sheet flow, and that the crucial simplifications are not achieved.
Seeking transparency, international arbitration users propose to gather feedback
Authors: Bleemer Russ
Published: December 2007

A group of international attorneys decide to do something about the arbitrator selection issues they had been chatting about on a list serv. The result is a new arbitrator feedback form, and a proposal to collect information for a subscription database. Also, details on a new international pledge under which attorneys will put ADR forward as a first option
Analysis and elimination of the output voltage imbalance for a half‐bridge boost rectifier under mismatched loads
Authors: Lo Yu‐Kang , Ho Chin‐Tse , Chiu Huang‐Jen
Published: December 2007

In this letter, the voltage imbalance between the dual output DC voltages of a half‐bridge boost rectifier with mismatched loads is analyzed by adopting an averaged circuit model. A compensating signal proportional to the voltage difference is added in the current command to eliminate the voltage imbalance. In addition, the adverse effects of the compensating current to the input power factor are discussed. Experimental results on a prototype circuit are given to confirm the theoretical analysis. Copyright © 2007 John Wiley & Sons, Ltd.
Evaluation of gliclazide ability to attenuate the hyperglycaemic ‘memory’ induced by high glucose in isolated human endothelial cells
Authors: Corgnali Maddalena , Piconi Ludovica , Ihnat Michael , Ceriello Antonio
Published: December 2007

Background

Patients with long‐term exposure to high levels of hyperglycaemia remain more susceptible to diabetes‐related complications, even with subsequent lower levels of hyperglycaemia. We sought to confirm the hypothesis that exposure to continuous increased glucose results in a memory of cellular stress in isolated endothelial cells, even when switched back to normal glucose, and to investigate the ability of gliclazide to attenuate this phenomenon.

Methods

Human umbilical vein endothelial cells were incubated for 21 days in normal glucose (5 mmol/L), high glucose (30 mmol/L), or high glucose for 14 days followed by normal glucose for 7 days (memory condition). The effects of gliclazide (10 µmol/L) and glibenclamide (1 µmol/L) were evaluated in the memory condition and added to the culture media early (first 14 days), late (last 7 days), or throughout the study. Oxidative stress and cell apoptosis parameters were investigated.

Results

Continuous high glucose increased reactive oxygen species, 8‐OHdG, nitrotyrosine, caspase‐3, and reduced Bcl‐2 expression. These deleterious effects were also observed in the memory condition. Gliclazide applied early or throughout the study improved all parameters. In contrast, glibenclamide showed no relevant effect on study parameters.

Conclusions

Our results suggest that gliclazide prevents endothelial cell apoptosis by reducing oxidative stress. The results appear to confirm the hypothesis that exposure of cells to continuous increased glucose results in a hyperglycaemic cellular memory that remains, even when cells are switched back to normal glucose. Gliclazide attenuated this cellular memory, decreasing oxidative stress and protecting vascular endothelial cells from apoptosis. Copyright © 2007 John Wiley & Sons, Ltd.
The clinical significance of loss of control over eating in overweight adolescents
Authors: Goldschmidt Andrea B. , Jones Megan , Manwaring Jamie L. , Luce Kristine H. , Osborne Megan I. , Cunning Darby , Taylor Katie L. , Doyle Angela Celio , Wilfley Denise E. , Taylor C. Barr
Published: December 2007

Objective:

Given limited data on the diagnostic validity of binge eating disorder (BED) in adolescents, this study sought to characterize overweight adolescents according to types of overeating episodes.

Method:

Ninety‐six adolescents (ages 13–17 years) with recurrent binge eating (BE), loss of control with or without overeating (subclinical BE; SUB), overeating without loss of control (OE), and no overeating or loss of control episodes (CONTROL) were compared on weight/shape concerns and depressive symptoms using ANCOVA and post‐hoc least squares difference tests.

Results:

BE and SUB adolescents had higher weight/shape concern scores than OEs and CONTROLs (ps < .01). BE and SUB adolescents had higher depression scores than CONTROL adolescents (ps < .05). BE adolescents had greater depression scores than OE (p < .01) but not SUB adolescents.

Conclusion:

Loss of control over eating signals increased impairment independent of overeating in adolescents. Results support refining BED criteria for youth to reflect this distinction. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord, 2008
The quality of treatment of eating disorders: A comparison of the therapists' and the patients' perspective
Authors: de la Rie Simone , Noordenbos Greta , Donker Marianne , van Furth Eric
Published: December 2007

Objective:

The aims of this study were to investigate the quality of treatment of eating disorders (EDs) from the therapists' and patients' perspective and to compare their views.

Method:

The Questionnaire for Eating Problems and Treatment (QEPT) was administered to 73 therapists working with patients with ED, to 156 current ED and 148 former ED patients. The QEPT addresses the quality of treatment of EDs. ED diagnosis was assessed by the Eating Disorder Examination Questionnaire. Answers were analyzed quantitatively and qualitatively.

Results:

Both therapists and patients most often mentioned focus of treatment, therapeutic alliance, and communicational skills as important aspects of the quality of treatment. However, they valued similar topics differently. Therapists valued the focus on ED symptoms and behavioral change more highly, whereas patients underscored the importance of the therapeutic relationship and addressing underlying problems. Most therapists work from a cognitive behavioral orientation, but protocol‐based treatment was not found important.

Conclusion:

There is an avid need for dissemination of evidence‐based treatment. Therapists' and patients' views supplement current evidence‐based knowledge on treatment quality of EDs. Optimal treatment of EDs will be facilitated when these three bodies of knowledge—the available evidence and the therapists' and patients' views—are integrated. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord, 2008
The duration of severe insulin omission is the factor most closely associated with the microvascular complications of Type 1 diabetic females with clinical eating disorders
Authors: Takii Masato , Uchigata Yasuko , Tokunaga Shoji , Amemiya Naoko , Kinukawa Naoko , Nozaki Takehiro , Iwamoto Yasuhiko , Kubo Chiharu
Published: December 2007

Objective:

To investigate which features of eating disorders are associated with retinopathy and nephropathy in Type 1 diabetic females with clinical eating disorders.

Method:

Participants were 109 Type 1 diabetic females with clinical eating disorders diagnosed by the structured clinical interview for DSM‐IV (bulimia nervosa [n = 70], binge‐eating disorder [n = 28], anorexia nervosa [n = 7], and eating disorder not otherwise specified [n = 4]). Retinopathy and nephropathy were screened and demographic, medical, and eating disorder related factors were investigated. To identify the factors associated with each complication, logistic regression analysis was done.

Results:

Duration of severe insulin omission and duration of Type 1 diabetes were significantly associated with retinopathy (odds ratios = 1.35 and 1.23, respectively) and nephropathy (odds ratio = 1.35 and 1.21, respectively) in multivariate regression analyses.

Conclusion:

Of the various problematic behavioral factors related to eating disorders, the duration of severe insulin omission was the factor most closely associated with the retinopathy and nephropathy of Type 1 diabetic females with clinical eating disorders by multivariate analysis. This finding may help patients who deliberately omit insulin become aware of medical risk of insulin omission. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord, 2008
Personality and eating behaviors: A case–control study of binge eating disorder
Authors: Davis Caroline , Levitan Robert D. , Carter Jacqueline , Kaplan Allan S. , Reid Caroline , Curtis Claire , Patte Karen , Kennedy James L.
Published: December 2007

Objective:

Questions have been raised about the validity of binge eating disorder (BED) as psycho‐pathologically distinct from other forms of overeating. Our purpose was to ascertain whether BED individuals differed in important ways from nonbinging obese adults.

Method:

BED adults were recruited from the community as were weight‐matched (obese) and normal‐weight control (NWC) groups. All groups were equivalent for age and gender distribution, and were assessed on several personality traits and eating behaviors.

Results:

BED individuals and obese controls did not differ on the personality traits. Both were more reward sensitive, and had greater anxiousness, impulsivity, and addictive personality traits than NWC. However, BED individuals reported significantly greater hedonic eating compared with the obese, who had higher levels than NWC.

Conclusion:

Our findings provided no evidence of a psychological identity unique to obese adults with BED although their eating behaviors are markedly hedonically driven—i.e., more responsive to factors external to physiological needs. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2008
Development of Pharmaceutical Drugs, Drug Intermediates and Ingredients by Using Direct Organo‐Click Reactions
Authors: Ramachary Dhevalapally B. , Kishor Mamillapalli , Reddy Y. Vijayendar
Published: December 2007

Here we report on our studies of the use of combinations of amino acids, amines, K2CO3 or Cs2CO3 and CuSO4/Cu for catalysing green cascade reactions. We aimed to prepare the highly reactive and substituted olefin species 7 and 8, under very mild and environmentally friendly conditions, thus giving the hydrogenated products 10 and 12 through the action of Hantzsch ester (4) by self‐catalysis through decreasing the HOMO–LUMO energy gaps between olefins 7/8 and Hantzsch ester (4) through biomimetic reductions. Highly useful compounds 10 to 14 were assembled from simple substrates such as aldehydes 1, ketones 2, CH acids 3, Hantzsch ester (4) and alkyl halides 5 by diversity‐oriented green synthesis involving cascade olefination/hydrogenation (O/H), olefination/hydrogenation/alkylation (O/H/A) and hydrogenation/olefination/hydrogenation (H/O/H) reaction sequences in one‐pot fashion with stereospecific organo‐ and organo‐/metal‐carbonate catalysis. Highly functionalized diverse compounds such as 10 to 14 are biologically active products and have found wide applications as pharmaceutical drugs, drug intermediates and drug ingredients. For the first time in organocatalysis, we report the O/H/A/TE reaction to furnish high yields of transesterification products 11 by simply mixing the reactants under proline/K2CO3 catalysis conditions. Additionally, a novel organocatalytic H/O/H reaction sequence for the synthesis of alkyl‐substituted aromatics has been developed. Furthermore, for the first time we have developed organocatalysed cascade olefination/hydrogenation/hydrolysis (O/H/H) reactions to furnish highly useful materials such as 2‐oxochroman‐3‐carboxylic acid (14kc) and 2‐amino‐4H‐chromene‐3‐carbonitrile (14kj) in good yields. Experimentally simple and environmentally friendly organocatalytic two‐carbon homologation through cascade O/H/H reactions of aldehydes 1, Meldrum's acid (3c), Hantzsch ester (4) and acetic acid/triethylamine in ethanol has been demonstrated. Additionally, we have developed a green synthesis of the highly substituted 1,2,3‐triazole 17 from simple substrates through a two‐step combination of olefination/hydrogenation/alkylation and Huisgen cycloaddition reaction sequences under stereospecific organocopper catalysis conditions. In this paper we have found strong support for our hypothesis that, “decreasing the HOMO–LUMO energy gap between olefins 7/8 and Hantzsch ester (4) will drive the biomimetic hydrogenation reaction by self‐catalysis”. This self‐catalysis was further confirmed with many varieties of examples.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Carbon Paste Electrode Plated with Lead Film. Voltammetric Characteristics and Application in Adsorptive Stripping Voltammetry
Authors: Bobrowski Andrzej , Królicka Agnieszka , Łyczkowska Ewa
Published: December 2007

A lead film plated in situ at a carbon paste support was tested as a novel, potential electrode for adsorptive stripping voltammetric determination of cobalt traces in an ammonia buffer solution. To show the practical applicability of the new electrode, a catalytic adsorptive Co system in a supporting electrolyte containing 0.1 M ammonia buffer, 5×10−4 M nioxime and 0.25 M nitrite was selected and investigated as a model solution. Pb and Co ions were simultaneously accumulated in situ on the electrode surface: Pb ions electrochemically at −1.3 V) and then at −0.75 V, at which potential the Co(II)‐nioximate complex was also pre‐concentrated via adsorption. Instrumental parameters, such as the time of nucleation and formation of Pb film deposits, the time of accumulation of the Co‐nioxime complex at the PbF/CPE, and the procedures of electrode regeneration, were optimized to obtain good reproducibility and sensitivity of the Co response. The optimized procedure yields favorable and highly stable stripping responses with good precision (RSD=3% for a 5×10−8 M Co) and good linearity (up to 5×10−7 M, coefficient of determination, R=0.996). The detection limit was 4×10−10 M Co (0.023 μg L−1) for an accumulation time of 120 s. The method enables the determination of Co in the presence of high excesses of Ni or Zn. The voltammetric data were correlated with the structural characterization by scanning electron microscopy (SEM) and X‐ray fluorescence spectroscopy (XRF).
The γ‐H2A.X: Is it just a surrogate marker of double‐strand breaks or much more?
Authors: Ismail Ismail Hassan , Hendzel Michael J
Published: December 2007

In recent years, several histone modifications have been implicated in the cellular response to DNA double‐strand breaks (DSBs). One of the best characterized histone modifications important in DSB repair is the phosphorylation of histone H2A variant, H2A.X. In response to DSBs, H2A.X is phosphorylated and this phosphorylation is required for DSB signaling and the retention of repair proteins at the break site. Despite the existing picture that the function of H2A.X is to promote DNA repair, very recent data suggest that the phosphorylation of histone H2A.X has additional functions. This is analogous to histone H3 phosphorylation on serine 10, which participates in seemingly incompatible functions—transcriptional activation and mitosis. In this review, we discuss the role of histone H2A.X in maintaining genomic stability and review emerging evidence that histone H2A.X is multifunctional. Environ. Mol. Mutagen., 2008. © 2007 Wiley‐Liss, Inc.
On the reliability of long‐period response spectral ordinates from digital accelerograms
Authors: Paolucci Roberto , Rovelli Antonio , Faccioli Ezio , Cauzzi Carlo , Finazzi Daniela , Vanini Manuela , Di Alessandro Carola , Calderoni Giovanna
Published: December 2007

Using records from co‐located broadband and digital strong motion (SM) instruments, it is first shown that the displacement waveforms obtained by double integration of the accelerogram need not be free of unrealistic baseline drift to yield reliable spectral ordinates up to at least 10 s. Secondly, to provide objective criteria for selecting reliable digital SM records for ground motion predictions at long periods, a set of synthetic accelerograms contaminated by random long‐period noise has been used, and the difference between the original accelerograms and the spurious ones in terms of response spectra has been quantified, by introducing a noise index that can be easily calculated based on the velocity waveform of the record. The results of this study suggest that high‐pass filtering the digital acceleration record from a cutoff period selected to suppress baseline drifts on the displacement waveform appears to be in most cases too conservative and unduly depletes reliable information on long‐period spectral ordinates. Copyright © 2007 John Wiley & Sons, Ltd.
Unity in diversity: Lessons from macaque societies
Authors: Thierry Bernard
Published: December 2007

The macaque radiation is as old as the hominin radiation, approximately 7 million years. After Homo, Macaca has the widest geographical range among primates, and both of these genera are present in tropical and temperate regions as well. Whereas the single extant representative of the genus Homo diverged through processes of cultural diversification, extant species of macaques emerged through processes of evolutionary diversification. Macaque societies are characterized by profound unity and great diversity, and can best be described as variations on the same theme. To understand macaque variation and adaptation, we must take into account the processes that insure the persistence of their societies across generations and environments.
Advances in optically stimulated luminescence dating of individual grains of quartz from archeological deposits
Authors: Jacobs Zenobia , Roberts Richard G.
Published: December 2007

Paleoanthropologists and archeologists interested in occupation histories, faunal remains, and objects of material culture have become increasingly reliant on optically stimulated luminescence (OSL) dating to construct Quaternary chronologies. In part, the increased use of OSL dating reflects its capacity to date events beyond the range of radiocarbon dating and in contexts where suitable organic materials are absent. An earlier review in Evolutionary Anthropology by Feathers1 provides a general account of the principles of luminescence dating. Since then, however, important advances have been made in OSL dating of quartz, so that it is now possible to date individual sand‐sized grains and thereby resolve issues of postdepositional mixing of archeological sediments. In this review, we discuss the most important of these advances and their implications with regard to improved age control of archeological sites. We cover aspects of instrumental and methodological development that have facilitated the widespread measurement of single grains related to archeological questions and illustrate our review with some examples of where archeological problems have been resolved using single‐grain OSL dating. We do not propose single‐grain dating as a panacea, because there are instances where it is not straightforward to use or the results may be difficult to interpret; dating in such contexts remains the subject of continuing research.
The effect of oxygen concentration on CO and soot yields in fires
Authors: Brohez S. , Marlair G. , Delvosalle C.
Published: December 2007

In addition to global ventilation effects on fires, vitiation of air can also affect the generation of chemical species in a built environment. Experiments were performed at lab‐scale with the Fire Propagation Apparatus (ASTM E2058) in order to study the effect of air vitiation on CO and soot yields. Results regarding the fuel burning rate are also presented. Both carbon dioxide and nitrogen were used as diluents in the inlet air flows. The oxygen concentration was decreased stepwise until the extinction point was reached. A first set of experiments was performed in well‐ventilated fire conditions (equivalence ratio between 0.1 and 0.25). A second set of experiments was carried out in under‐ventilated fire conditions (equivalence ratio equal to 1.1). A procedure is proposed for experimental data reduction. The results revealed themselves useful for improving combustion sub‐model predictions. Copyright © 2007 John Wiley & Sons, Ltd.
Alluvial cycles, climate, and puebloan settlement shifts near Zuni Salt Lake, New Mexico, USA
Authors: Huckleberry Gary , Duff Andrew I.
Published: December 2007

Twenty‐seven 14C dates from alluvial deposits and soils exposed in modern arroyos near Zuni Salt Lake, New Mexico, provide evidence for past episodes of piedmont and valley entrenchment by low‐order ephemeral streams. We recognize two episodes of entrenchment at A.D. 900–1050 and A.D. 1300–1400 that correlate to other arroyo‐cutting events in the region. Episodes of piedmont and valley entrenchment are followed by approximately 200–300 years of aggradation until arroyos are filled and shallow flooding with expansive sedimentation returns, completing an alluvial cycle. Many alluvial cycles appear synchronous across much of the southern Colorado Plateau and are likely linked to changes in climate and flood regime. Flooding on small basin drainages near Zuni Salt Lake is related to the Southwest summer monsoon, a meteorological event that is poorly linked to El Niño. Alluvial cycles on small basin drainages affected indigenous floodwater farming by locally lowering water tables and reducing irrigable area during phases of entrenchment and contributed to the aggregation of Puebloan communities on the southern Colorado Plateau in the A.D. 1300s. © 2008 Wiley Periodicals, Inc.
Book Reviews
Authors: Watson Patty Jo
Published: December 2007

The Neolithic revolution in the Near East: Transforming the human landscape. Alan H. Simmons, 2007, The University of Arizona Press, Tucson, Arizona, xvii +339 pp., $55.00 (cloth).
Improved application of independent component analysis to functional magnetic resonance imaging study via linear projection techniques
Authors: Long Zhiying , Chen Kewei , Wu Xia , Reiman Eric , Peng Danling , Yao Li
Published: December 2007

Spatial Independent component analysis (sICA) has been widely used to analyze functional magnetic resonance imaging (fMRI) data. The well accepted implicit assumption is the spatially statistical independency of intrinsic sources identified by sICA, making the sICA applications difficult for data in which there exist interdependent sources and confounding factors. This interdependency can arise, for instance, from fMRI studies investigating two tasks in a single session. In this study, we introduced a linear projection approach and considered its utilization as a tool to separate task‐related components from two‐task fMRI data. The robustness and feasibility of the method are substantiated through simulation on computer data and fMRI real rest data. Both simulated and real two‐task fMRI experiments demonstrated that sICA in combination with the projection method succeeded in separating spatially dependent components and had better detection power than pure model‐based method when estimating activation induced by each task as well as both tasks. Hum Brain Mapp, 2009. © 2007 Wiley‐Liss, Inc.
When do infants differentiate profile face from frontal face? A near‐infrared spectroscopic study
Authors: Nakato Emi , Otsuka Yumiko , Kanazawa So , Yamaguchi Masami K. , Watanabe Shoko , Kakigi Ryusuke
Published: December 2007

The objective of the present study was to determine whether a developmental difference occurs in brain activity when infants look at frontal and profile views using near‐infrared spectroscopy (NIRS), which is an optical imaging technique used to measure changes in the concentrations of oxyhemoglobin (oxy‐Hb), deoxyhemoglobin (deoxy‐Hb), and total hemoglobin (total‐Hb). For this objective, we compared NIRS results in two age groups, 5‐ and 8‐month‐old infants, while they were looking at frontal views, profile views, and objects. We found that the concentration of oxy‐Hb and total‐Hb in the 5‐month‐old group increased for only frontal views in the right temporal regions. In contrast, the concentration of oxy‐Hb and total‐Hb in the 8‐month‐old group increased for both frontal and profile views in the right temporal regions. Therefore, the present study indicated that the right hemisphere was dominant for the perception of profile views as well as frontal views. In addition, the most important and interesting finding was that the infants' brain activity of the face area would become view‐invariant at the age of 8 months but not at 5 months. The developmental period for view‐invariant face recognition has been discussed in previous psychological studies, but this is the first objective study to confirm that the period is between 5‐ and 8‐months by measuring the blood flow in the brain using NIRS. Hum Brain Mapp, 2009. © 2007 Wiley‐Liss, Inc.
Functional connectivity patterns during motor behaviour: The impact of past on present activity
Authors: Serrien Deborah J.
Published: December 2007

Everyday behaviour often depends on the performance of multiple movements executed in a particular order. Here, the impact of task history on the neural activation patterns of motor behaviour is examined by evaluating unimanual and bimanual actions that are produced in a serial arrangement, such that switching between tasks is required. Cortical dynamics was assessed by means of EEG coherence in the β frequency band (13–30 Hz). Results showed that although behavioural performance was not affected, switching trials induced increased coherence as compared to control (repeat) trials. Thisreorganization was dependent on task history and was more pronounced for unimanual than for bimanual tasks. Overall, the data illustrate that neural processing of motor behaviour within a serial arrangement integrates past and present activity, and accordingly impacts on neural efficiency. Hum Brain Mapp, 2009. © 2007 Wiley‐Liss, Inc.
Re‐entrant projections modulate visual cortex in affective perception: Evidence from Granger causality analysis
Authors: Keil Andreas , Sabatinelli Dean , Ding Mingzhou , Lang Peter J. , Ihssen Niklas , Heim Sabine
Published: December 2007

Re‐entrant modulation of visual cortex has been suggested as a critical process for enhancing perception of emotionally arousing visual stimuli. This study explores how the time information inherent in large‐scale electrocortical measures can be used to examine the functional relationships among the structures involved in emotional perception. Granger causality analysis was conducted on steady‐state visual evoked potentials elicited by emotionally arousing pictures flickering at a rate of 10 Hz. This procedure allows one to examine the direction of neural connections. Participants viewed pictures that varied in emotional content, depicting people in neutral contexts, erotica, or interpersonal attack scenes. Results demonstrated increased coupling between visual and cortical areas when viewing emotionally arousing content. Specifically, intraparietal to inferotemporal and precuneus to calcarine connections were stronger for emotionally arousing picture content. Thus, we provide evidence for re‐entrant signal flow during emotional perception, which originates from higher tiers and enters lower tiers of visual cortex. Hum Brain Mapp, 2009. © 2007 Wiley‐Liss, Inc.
Functional neuroanatomy of CCK‐4‐induced panic attacks in healthy volunteers
Authors: Eser Daniela , Leicht Gregor , Lutz Jürgen , Wenninger Stephan , Kirsch Valerie , Schüle Cornelius , Karch Susanne , Baghai Thomas , Pogarell Oliver , Born Christine , Rupprecht Rainer , Mulert Christoph
Published: December 2007

Experimental panic induction with cholecystokinin tetrapeptide (CCK‐4) is considered as a suitable model to investigate the pathophysiology of panic attacks. While only a few studies investigated the brain activation patterns following CCK‐4, no data are available on the putative involvement of the amygdala in the CCK‐4 elicited anxiety response. We studied the functional correlates of CCK‐4‐induced anxiety in healthy volunteers by means of functional magnetic resonance imaging (fMRI) and region of interest (ROI) analysis of the amygdala. Sixteen healthy volunteers underwent challenge with CCK‐4 compared with placebo in a single‐blind design. Functional brain activation patterns were determined for the CCK‐4‐challenge, the placebo response and anticipatory anxiety (AA). CCK‐4‐induced anxiety was accompanied by a strong and robust activation (random effects analysis, P < 0.00001, uncorrected for multiple testing) in the ventral anterior cingulate cortex (ACC), middle and superior frontal gyrus, precuneus, middle and superior temporal gyrus, occipital lobe, sublobar areas, cerebellum, and brainstem. In contrast, random effects group analysis for placebo and AA using the same level of significance generated no significant results. Using a more liberal level of significance, activations could be observed in some brain regions such as the dorsal part of the ACC during AA (random effects analysis, P < 0.005). Overall functional responses did not differ between panickers and nonpanickers. Only 5 of 11 subjects showed strong amygdala activation. However, ROI analysis pointed towards higher scores in fear items in these subjects. In conclusion, while overall brain activation patterns are not related to the subjective anxiety response to CCK‐4, amygdala activation may be involved in the subjective perception of CCK‐4‐induced fear. Hum Brain Mapp, 2009. © 2007 Wiley‐Liss, Inc.
Prediction of microvascular invasion before curative resection of hepatocellular carcinoma
Authors: Kim Beom Kyung , Han Kwang Hyub , Park Young Nyun , Park Mi Suk , Kim Kyung Sik , Choi Jin Sub , Moon Byung Soo , Chon Chae Yoon , Moon Young Myoung , Ahn Sang Hoon
Published: December 2007

Background

The accurate staging of hepatocellular carcinoma (HCC) is important in establishing treatment strategies and prognosis. Among tumor factors, microvascular invasion, one of TNM staging components and prognostic factors, is underestimated preoperatively, due to inaccuracy of imaging modalities. We investigated preoperative predictors of microvascular invasion.

Methods

We reviewed 190 consecutive HCC patients given curative resection from 1999 to 2006. All were treatment‐naive and monitored every 3 months after resection. Tumor recurrence, survivals, and clinicopathological factors associated with microvascular invasion were analyzed.

Results

The 5‐year disease‐free survival (DFS) rate was 39.4%(median follow‐up duration: 35 months). On resection pathology, 38.9% (74/190 patients) had microvascular invasion undetected preoperatively, using liver spiral computed tomography (CT) or angiography. Independent predictors of microvascular invasion were tumor size (P = 0.043), number (P = 0.011), and Edmondson grade (P = 0.001). Patients with Edmondson grade 1 and size <5 cm had no microvascular invasion, while those with grade ≥2 had higher incidences (7/18 patients, 38.8%) even in small tumor (<2 cm). When tumors recurred, presence of microvascular invasion independently increased incidences of multiple tumors, portal vein invasion, and diffuse‐infiltrative patterns significantly.

Conclusions

Preoperative predictors of microvascular invasion are tumor size, number, and Edmondson grade, which may be useful for making clinical decisions in both non‐surgical and surgical candidates. J. Surg. Oncol. 2008;97:246–252. © 2007 Wiley‐Liss, Inc.
Kinetic and equilibrium study of the enantioseparation of paroxetine intermediate on amylose and tartaric acid‐based chiral stationary phases
Authors: Bao Zongbi , Su Baogen , Ren Qilong
Published: December 2007

trans‐(–)‐Paroxetine is a selective 5‐hydroxytryptamine (5‐HT) reuptake inhibitor currently used as an antidepressant. trans‐(±)‐3‐Ethoxycarbonyl‐4‐(4′‐fluorophenyl)‐1‐methylpiperidine‐2,6‐dione is an important intermediate of trans‐(–)‐paroxetine. It was separated on amylose and tartaric acid‐based chiral stationary phases by HPLC. The equilibrium constants and overall mass transfer coefficients together with the axial dispersion coefficients were experimentally determined by moment analysis based on the lumped kinetic model of chromatography. In case of Kromasil CHI‐TBB, the equilibrium constants measured were found to be 8.36 and 9.37 for trans‐(+) and trans‐(–) enantiomers, respectively. For Chiralpak AD‐H, the equilibrium constants were 6.68 and 4.13 for trans‐(+) and trans‐(–) enantiomers, respectively. The axial dispersion coefficients of both enantiomers on Kromasil CHI‐TBB column were about one order of magnitude greater than on Chiralpak AD‐H. Fast kinetics of mass transfer in both chiral stationary phases was observed. Their overall mass transfer coefficients on Kromasil CHI‐TBB and Chiralpak AD‐H were 32.12, 33.18, 26.50, 46.85 s–1 for trans‐(+) and trans‐(–) enantiomers, respectively. The parameters obtained were utilized to simulate the elution profiles, and the simulated and experimental results match well, which confirmed that the parameters obtained in this study were valid.
Ischemia‐reperfusion injury. A phenomenon, that also occurs in the bone
Authors: de Groot H.
Published: December 2007

Ischemia‐reperfusion injury of the bone occurs due to traumatic and non‐traumatic alterations affecting blood supply to the bone. It is likely to occur also upon insertion of an implant. Ischemia‐reperfusion injury of the bone has been studied by interruption of blood supplyin situ, in limb replantation/transplantation models, in revascularized bone grafts and non‐vascularized bone fragments, as well as in isolated cultured cells. All cells of the bone are affected, including osteoblasts, osteocytes, osteoclasts, chondrocytes, and bone marrow cells. Critical ischemia times for induction of bone cell death, either in the ischemic period or following reperfusion, are in the range of 3 to 7 h. These critical ischemia times are significantly increased by decreasing the temperature from 37 °C to 0–4 °C. Anoxia is the most likely trigger of cell injury in the ischemic phase. In the reperfusion phase, reactive oxygen species are decisively involved in the injurious process. In general, however, the available information on the mechanism of ischemia‐reperfusion injury of the bone is relatively sparse. On the other hand, there are clear similarities to the mechanisms of ischemia‐reperfusion injury known from other organs, and there is a clear potential for protection against ischemia‐reperfusion injury of the bone.
Second generation (low modulus) titanium alloys in total hip arthroplasty
Authors: Schuh A. , Bigoney J. , Hönle W. , Zeiler G. , Holzwarth U. , Forst R.
Published: December 2007

Titanium alloys ‐ type (α+β) ‐ like Ti6Al7Nb or Ti6Al4V are widely used in cementless total hip arthroplasty due to their lower modulus, biocompatibility and enhanced corrosion resistance in comparison to Stainless Steel or Cobalt‐Chromium implant materials. Several articles report about atrophy of the proximal femur in cases where long stems with a big diameter made of (α+β) Titanium alloys with a relatively high value of the Youngs’ Modulus (110 GPa) in comparison to the Youngs’ Modulus of cortical bone (15–25 GPa) have been implanted using a prosthesis design with distal anchorage technique. Meanwhile several implant manufacturers have developed a new group of biocompatible Beta‐Titanium alloys with a lower Youngs’ Modulus around 70 GPa. This article gives an overview of the current status of available low modulus Titanium alloys including their mechanical characteristics and future developments.
Influence of nickel ions on human multipotent mesenchymal stromal cells (hMSCs)
Authors: Habijan T. , Bremm O. , Esenwein S. A. , Muhr G. , Köller M.
Published: December 2007

Nickel‐Titanium‐Shape‐Memory‐Alloys (NiTi‐SMA) are of biomedical interest due to an unusual range of pure elastic deformability (superelasticity) and the shape memory effect which allows this material to return to a predictable previously memorized shape after external changes in temperature. HMSCs (human multipotent mesenchymal stromal cells) are currently the most promising cell type for regenerative medicine and tissue engineering, due to the ability to differentiate into several tissues such as bone, tendon, cartilage or muscle. For tissue engineering newly developed porous NiTi‐SMA materials are evaluated preloaded with hMSCs. For biocompatibility testing the high nickel content (50 %at) of NiTi‐SMA plays a critical role. To analyse the influence of Ni‐ions on hMSCs viability and activation, cells were cultured with or without NiCl2 for 24h and 7days. Cells were either seeded in media containing NiCl2 or the NiCl2 was later added to already adherent cells. Cell metabolism, proliferation and viability were analysed by alamarBlueTM assay or fluorescence microscopy. Cytokine (IL‐6, 8, 11) release from hMSCs was determined by ELISA. NiCl2 concentrations below 25 μg/ ml were well tolerated by the cells. A significant decrease in cell proliferation occurred at threshold values of 200 μg/ ml (24 h) and 25 μg/ ml (7 d). There was a significant, dose dependent increase in the release of IL‐8 from hMSCs cultured in the presence of sub toxic NiCl2 concentrations. The present study demonstrates for the first time that high but non‐toxic concentrations of Ni2+ are capable to activate hMSCs. Thus high Ni2+ concentrations apart from allergen‐ or particle‐induced inflammation, may lead to tissue inflammation in the vicinity of a NiTi‐SMA implant in vivo and subsequently to implant failure e.g. due to implant loosening.
Compartmentalized, multiphasic nanocolloids with potential applications in drug delivery and biomedical imaging
Authors: Roh K.‐H. , Yoshida M. , Lahann J.
Published: December 2007

Nanoparticles are excellent candidates for drug delivery or biomedical imaging, because they often exhibit superb tuneability of critical properties, such as size, surface characteristics, degradation rate, and therefore drug release rates. We have recently developed a route towards fabrication of sub‐micron particles that relies on electrohydrodynamic co‐jetting. In this process, fluid manipulation in an electrical field is used to fabricate large quantities of multi‐compartment particles, where individual compartments can be independently loaded with different drugs or selectively surface‐modified. In this contribution, aspects of multifunctional particles for biomedical applications are reviewed and a specific focus is given to recent progress with compartmentalized, multiphasic nanocolloids in our laboratory.
Torsion sensitivity in NMR of aligned molecules: study on various substituted biphenyls
Authors: Sahakyan Aleksandr B. , Shahkhatuni Aleksan G. , Shahkhatuni Astghik A. , Panosyan Henry A.
Published: December 2007

To estimate the torsion sensitivity of dipolar coupling, biphenylic molecules were chosen as probes due to their relatively simple structure and the surprisingly high ambiguity of the only flexible parameter—the interring torsion angle. Solution structures of 4,4′‐dibromobiphenyl and 4,4′‐diiodobiphenyl are reported for the first time in two liquid crystals I52 and ZLI 1695. The comparison of NMR structures of various para‐substituted biphenyls (BPs), calculated by the additive potential maximum entropy (APME) approach, shows that the small spread of torsion angle values in case of different solvents and para‐substituents is in good agreement with theoretical expectations from hybrid density functional theory (DFT) methods. Furthermore, the real structural changes of interring torsion and the prevalence of solvent effects over para‐halosubstitution can be correctly revealed from these small fluctuations. Copyright © 2007 John Wiley & Sons, Ltd.
13C NMR studies of heterocyclic naphtho‐ and anthraquinones. Deshielding effect on the carbonyl carbon with methyl substitution
Authors: Salas Cristian , Armstrong Veronica , López Claudio , A. Tapia Ricardo
Published: December 2007

13C chemical shift assignment of several methyl substituted heterocyclic naphtho‐ and anthraquinones, including dihydronaphthofuranquinones, azaanthraquinones, benzopyrroloquinolinediones and benzothiophenoquinolinediones, are described. A deshielding effect due to a methyl group was observed over the neighbouring carbonyl carbon, in every case studied. 13C assignments were based on 2D experiments. Copyright © 2007 John Wiley & Sons, Ltd.
Qualitative and quantitative differences of cytoskeleton proteins in embryos produced in vitro, in vivo, and by somatic nuclear transfer
Authors: Poehland R. , Tomek W. , Becker F. , Kurth J. , Kanitz W. , Bhojwani S.
Published: December 2007

The cytoskeleton, consisting of complex and dynamic systems of structural filaments, intermediate filaments and microtubules, is not only a structural element but also contributes to many cellular processes such as functional compartments, transportation, mitosis, secretion, formation of cell extensions, and intercellular communication. Suggestions in rat 2‐cell embryos that abnormal distributions of cytoskeletal proteins occurred following the initiations of developmental arrest and our former studies showing reduced intercellular contact zones in cloned bovine embryos prompted us to conduct comparative studies on 8‐cell stage bovine embryos from nuclear transfer (NT), in vitro, and in vivo production. Immunohistochemistry and Laser‐Scanning‐Microscopy facilitated detection of cytoskeleton proteins—α‐tubulin, F‐actin, β‐catenin, and the cell adhesion protein cadherin; image and cluster analysis were subsequently used to study the distribution pattern of the proteins, whereas Western blot was carried out for their qualitative and quantitative analysis. The maximum fluorescence intensity of stained alpha‐tubulin was observed in the cloned and the in vitro embryos. A significant higher intensity of staining for F‐actin was observed in the in vivo and in vitro embryos. In contrast, Western blot revealed no differences of actin, tubulin, and catenin between the three tested groups whereas a lower abundance of cadherin proteins in the cloned embryos was visible. The distribution of actin filaments in cloned embryos was more centric or one‐sided and not peripheral whereas the stained spots of catenin were smaller in comparison to in vivo or in vitro produced embryos. These differences recorded in the distribution patterns may be associated with cell physiological processes related to an influenced actin‐catenin‐cadherin system. In conclusion, reduced intercellular contacts coupled with abnormal distribution of cytoskeletal proteins seem to play an important role in the developmental arrest encountered normally at the 8‐cell stage in bovine cloned embryos. Mol. Reprod. Dev. 75: 1109–1119, 2008. © 2007 Wiley‐Liss, Inc.
A time‐independent approach for computing wave functions of the Schrödinger–Poisson system
Authors: Chien C.‐S. , Jeng B.‐W. , Li Z.‐C.
Published: December 2007

We describe a two‐grid finite element discretization scheme for computing wave functions of the Schrödinger–Poisson (SP) system. To begin with, we compute the first k eigenpairs of the Schrödinger–Poisson eigenvalue (ESP) problem on the coarse grid using a continuation algorithm, where the nonlinear Poisson equation is solved iteratively. We use the k eigenpairs obtained on the coarse grid as initial guesses for computing their counterparts of the ESP on the fine grid. The wave functions of the SP system can be easily obtained using the formula of separation of variables. The proposed algorithm has the following advantages. (i) The initial approximate eigenpairs used in the fine grid can be obtained with low computational cost. (ii) It is unnecessary to discretize the partial derivative of the wave function with respect to the time variable in the SP system. (iii) The major computational difficulties such as closely clustered eigenvalues that occur in the SP system can be effectively computed. Numerical results on the ESP and the SP system are reported. In particular, the rate of convergence of the proposed algorithm is O(h4). Copyright © 2007 John Wiley & Sons, Ltd.