bluuebunny/crossref_metadata_2025 huggingface dataset:
CLIP Method (Preoperative CT Image‐assessed Ligation of Inferior Pancreaticoduodenal Artery) Reduces Intraoperative Bleeding during Pancreaticoduodenectomy
Authors: Kawai Manabu , Tani Masaji , Ina Shinomi , Hirono Seiko , Nishioka Ryohei , Miyazawa Motoki , Uchiyama Kazuhisa , Shimamoto Tetsuya , Yamaue Hiroki
Published: November 2007

Background

No previous reports have prospectively discussed an operative approach to reducing intraoperative bleeding during pancreaticoduodenectomy (PD). We have established the preoperative CT image‐assessed ligation of inferior pancreaticoduodenal artery (IPDA) method (CLIP), which uses a preoperative three‐dimensional computed tomographic (3D‐CT) image to precisely detect the IPDA root intraoperatively and ligates the IPDA before the pancreas head is isolated. The aim of this study was to clarify whether the new operative approach reduces intraoperative bleeding compared with classical PD.

Method

Between October 2003 and May 2005, classical PD was performed (n = 48), and from June 2005 to September 2006, PD with the CLIP method was prospectively performed (n = 48) at Wakayama Medical University Hospital. The perioperative status of the patients in the two groups, including intraoperative bleeding, was compared.

Results

Median intraoperative bleeding in patients with the CLIP method was significantly reduced compared with classical PD (867 ml versus 728 ml; p = 0.026). Moreover, operative time, red blood cell transfusion (units), and red blood cell transfusion in patients with the CLIP method were significantly reduced compared with classical PD (p = 0.033, 0.042, 0.014, respectively). There were no differences in length from the SMA to the IPDA root when the preoperative measurement by 3D‐CT image (37.9 ± 8.9 mm) and the intraoperative findings (38.0 ± 8.8 mm) were compared (p = 0.6283).

Conclusions

The CLIP method is a useful and reliable operative technique for reducing intraoperative bleeding in PD.
Long‐term Outcome after Isolated Endarterectomy of the Femoral Bifurcation
Authors: Kechagias Aristotelis , Ylönen Kari , Biancari Fausto
Published: November 2007

Background

Long‐term outcome after endarterectomy of the femoral bifurcation has not been widely investigated, and the aim of this study was to assess its late results from a community‐wide perspective.

Patients and Methods

Between 1983 and 2006 111 isolated endarterectomies of the common femoral artery and/or the proximal part of the superficial femoral artery or profunda femoris were performed in 90 patients at the Oulu University Hospital, Oulu, Finland. A total of 77 limbs were treated surgically for claudication and 34 others for critical limb ischemia. Angiographic findings of 100 extremities were evaluated.

Results

The in‐hospital mortality rate was 1.8%. The mean follow‐up period was 5.9 years. At 5‐, 10‐, and 15‐year follow‐up the overall survival was 60.5%, 32.7%, and 17.6%, respectively (S.E < 0.05). A C‐reactive protein value ≥ 10 mg/l was predictive of poor late survival (p = 0.008). Limb salvage rates after isolated femoral endarterectomy at 5‐, 10‐, and 15‐year follow‐up were 93.7%, 93.7%, and 85.2%, respectively (S.E. < 0.08). Critical limb ischemia (p = 0.006) and current smoking (p = 0.027) were independent predictors of major lower limb amputation. A total of 41 limbs were subjected to ipsilateral vascular procedures after femoral endarterectomy, only one of which was re‐endarterectomy. Freedom from any ipsilateral revascularization procedure at 5‐, 10‐, and 15‐year follow‐up was calculated at 68.0%, 50.6%, and 42.5%, respectively (S.E. < 0.08). The overall linearized rate of reintervention on the ipsilateral limb was 0.16 ± 0.44/year. The linearized rate among patients who had any ipsilateral vascular reintervention was 0.43 ± 0.66/year.

Conclusions

Isolated femoral endarterectomy is a rather low‐risk and durable procedure. However, a significant number of reinterventions distal or proximal to the endarterectomized site can be expected in one third of patients.
Novel mutations in abetalipoproteinaemia and homozygous familial hypobetalipoproteinaemia
Authors: Vongsuvanh R. , Hooper A. J. , Coakley J. C. , Macdessi J. S. , O'Loughlin E. V. , Burnett J. R. , Gaskin K. J.
Published: November 2007

Abetalipoproteinaemia (ABL) and homozygous familial hypobetalipoproteinaemia (FHBL) are rare inherited disorders associated with low or undetectable levels of apolipoprotein B (apoB)‐containing lipoproteins. Patients present with the symptoms and sequelae of fat malabsorption, including fat‐soluble vitamin deficiencies. We describe two novel mutations: one an APOB gene mutation causing FHBL and the other a microsomal triglyceride transfer protein (MTP) gene mutation causing ABL. Two siblings of consanguineous parents were homozygous for an apoB mutation 4339delT causing an apoB‐30.9 truncation. In another family, a boy born to consanguineous parents was homozygous for a 319 bp in‐frame deletion of MTP exon 15 (c.2076‐39_2303+52del319). All three children presented with malabsorption and liver dysfunction and had similar very low serum lipid, apoB, and fat‐soluble vitamin levels. The FHBL parents had low serum lipid and apoB profiles distinguishing the disorder from the normal levels in ABL parents. Future patients presenting with FHBL or ABL should be genotyped to provide further insight into the varying clinical severity related to molecular heterogenicity in these two conditions.
Transcriptional activity of the RHOB gene is influenced by regulatory polymorphisms in its promoter region
Authors: Mahr Sandra , Müller-Hilke Brigitte
Published: November 2007

Osteoarthritis (OA) is a chronic joint disease with genetic as well as environmental factors contributing to its etiology. We recently identified RHOB as a gene overexpressed in osteoarthritis. Interestingly, RHOB harbors numerous polymorphisms in its promoter region and genotyping of OA patients and healthy controls revealed an association of the single nucleotide polymorphism (SNP) rs585017 with the disease. We here set out to investigate the influence of RHOB promoter polymorphisms on the transcriptional activity of the gene and we found evidence that the SNPs rs2602160 and rs585017 cooperate in regulating RHOB expression. In addition, a variable number of tandem repeats (VNTR) impacts on the RHOB transcriptional activity in a cell type restricted manner. These results mechanistically link our previous finding of an elevated RHOB expression to the disease associated SNP rs585017 and confirm a role for regulatory polymorphisms in osteoarthritis.
Population dynamics and intra-litter transmission patterns ofIsospora suisin suckling piglets under on-farm conditions
Authors: SOTIRAKI S. , ROEPSTORFF A. , NIELSEN J. P. , MADDOX-HYTTEL C. , ENøE C. , BOES J. , MURRELL K. D. , THAMSBORG S. M.
Published: November 2007

The aim of this study was to investigate the intra-litter infection dynamics ofIsospora suisunder natural conditions, and to study any association between parasite transmission and the contamination level of the farrowing pen by applying different interventions in order to reduce the transmission ofI. suisinfection within the litter. The study was divided in 2 trials including in total 22 litters (254 piglets). The first trial included 4 litters (where standard procedures practiced routinely on the farm piglets were applied) and the piglets were followed coprologically from farrowing until 2 weeks after weaning. The sows of those litters were also examined at various intervals before and after farrowing. The second trial included the application of 3 different management procedures: (A) standard farm hygiene and management procedures, (B) standard farm hygiene and management procedures+the first piglets found to excreteI. suisoocysts in each pen were removed from the pen, and (C) reduced cleaning. Each procedure was studied in 2 litters. This was replicated 3 times to yield a total of 18 litters. The results suggested that (i) the sow does not play an important role in transmission ofI. suisin the farrowing pen; (ii) in natural infections, both the age of the piglet age at onset of oocyst excretion and the oocyst excretion patterns may vary considerably; (iii) the course of oocyst excretion or development of diarrhoea is related to the time of initial infection and (iii) piglets, which are heavy at birth, are more prone to acquireI. suisinfection. Moreover, it was demonstrated that cleaning could be an effective means of restricting the spread of the parasite within the litter and thus the development of diarrhoea.
Psychobiologische Mechanismen sozialer Unterstützung
Authors: Ditzen Beate , Heinrichs Markus
Published: November 2007

Zusammenfassung. Epidemiologische Studien können eindrucksvoll nachweisen, dass Personen, die in stabile soziale Netzwerke eingebunden sind, zufriedener, gesünder und auch länger leben als sozial isolierte Personen. Einerseits wird vermutet, dass dieser gesundheitsfördernde Effekt sozialer Unterstützung durch Verhaltensänderungen vermittelt wird, welche auf nahestehende Personen zurückführbar sind. Auf der anderen Seite wird ein direkter protektiver Effekt sozialer Unterstützung auf die körperliche Stressreaktivität angenommen, der unterschiedliche salutogenetische Wirkungen haben könnte. Die möglichen vermittelnden biologischen Mechanismen dieses Effekts werden zunehmend in Labor- und Feldstudien untersucht. In diesem Artikel geben wir einen Überblick über die Ergebnisse psychobiologischer Untersuchungen zu den Einflüssen sozialer Unterstützung auf der Ebene des Herz-Kreislauf-Systems, des endokrinen Systems und des Immunsystems. Abschließend gehen wir auf erste Studien ein, in denen die zentralnervösen Mechanismen sozialer Unterstützung experimentell untersucht wurden, und fassen die Ergebnisse in einem Modell zusammen.
Unterschiedliche Wertschätzung, aber gleiche Unterstützungsbereitschaft
Authors: Vollmann Manja , Renner Britta , Matiba Katrin , Weber Hannelore
Published: November 2007

Zusammenfassung. Soziale Netzwerke und insbesondere soziale Unterstützung werden als ein zentraler vermittelnder Mechanismus zwischen Optimismus und Gesundheit diskutiert. In dieser Studie wird die Annahme geprüft, dass Optimisten, Pessimisten und Realisten unterschiedliche soziale Reaktionen hervorrufen. Den Probanden (N = 168) wurden Vignetten präsentiert, in denen eine Zielperson (Target) optimistisches, pessimistisches bzw. realistisches Bewältigungsverhalten in einer Stresssituation zeigt. Anschließend wurden per Fragebogen (a) die Bewertung des Verhaltens und der Persönlichkeit des Targets, (b) die Sympathie gegenüber dem Target sowie (c) die Bereitschaft zu sozialer Unterstützung erfasst. Hinsichtlich des Verhaltens, der Persönlichkeit sowie der Sympathie wurden die optimistischen und realistischen Targets positiver bewertet als die pessimistischen Targets. Allerdings gingen diese positiveren Bewertungen der Optimisten und Realisten im Vergleich zu den Pessimisten nicht mit einer höheren Unterstützungsbereitschaft einher. Der Zusammenhang zwischen Optimismus und Gesundheit wird möglicherweise nicht nur über die vom sozialen Umfeld tatsächlich zur Verfügung gestellte Unterstützung, sondern auch durch den Ausdruck sozialer Akzeptanz vermittelt.
Market Entry Decisions
Authors: Bolger Fergus , Pulford Briony D. , Colman Andrew M.
Published: November 2007

Abstract. In a market entry game, the number of entrants usually approaches game-theoretic equilibrium quickly, but in real-world markets business start-ups typically exceed market capacity, resulting in chronically high failure rates and suboptimal industry profits. Excessive entry has been attributed to overconfidence arising when expected payoffs depend partly on skill. In an experimental test of this hypothesis, 96 participants played 24 rounds of a market entry game, with expected payoffs dependent partly on skill on half the rounds, after their confidence was manipulated and measured. The results provide direct support for the hypothesis that high levels of confidence are largely responsible for excessive entry, and they suggest that absolute confidence, independent of interpersonal comparison, rather than confidence about one's abilities relative to others, drives excessive entry decisions when skill is involved.
Multisensory Identification of Natural Objects in a Two-Way Crossmodal Priming Paradigm
Authors: Schneider Till R. , Engel Andreas K. , Debener Stefan
Published: November 2007

Abstract. The question of how vision and audition interact in natural object identification is currently a matter of debate. We developed a large set of auditory and visual stimuli representing natural objects in order to facilitate research in the field of multisensory processing. Normative data was obtained for 270 brief environmental sounds and 320 visual object stimuli. Each stimulus was named, categorized, and rated with regard to familiarity and emotional valence by N = 56 participants (Study 1). This multimodal stimulus set was employed in two subsequent crossmodal priming experiments that used semantically congruent and incongruent stimulus pairs in a S1-S2 paradigm. Task-relevant targets were either auditory (Study 2) or visual stimuli (Study 3). The behavioral data of both experiments expressed a crossmodal priming effect with shorter reaction times for congruent as compared to incongruent stimulus pairs. The observed facilitation effect suggests that object identification in one modality is influenced by input from another modality. This result implicates that congruent visual and auditory stimulus pairs were perceived as the same object and demonstrates a first validation of the multimodal stimulus set.
Mask-Induced Priming and the Negative Compatibility Effect
Authors: Sumner Petroc
Published: November 2007

Abstract. Under certain conditions, masked primes have produced counter-intuitive negative compatibility effects (NCE), such that RT is increased, not decreased, when the target is similar to the prime. This NCE has been interpreted as an index of automatic motor inhibition, triggered to suppress the partial motor activation caused by the prime. An alternative explanation is that perceptual interactions between prime and mask produce positive priming in the opposite direction to the prime, explaining the NCE without postulating inhibition. Here the potential role of this “mask-induced priming” was investigated in two experiments, using masks composed of random lines. Experiment 1 compared masks that included features of the primes and targets with masks that did not. The former should create more mask-induced priming, but the NCE did not differ between masks. Experiment 2 employed masks that contained features of either one target or the other, but not both. These asymmetric masks produced significant mask-induced priming, but it was insufficient in size to account for the prime-related NCE. Thus mask composition can contribute to NCEs, but when random line masks are employed, the major source of the NCE seems to be motor-inhibition.
Roman Digit Naming
Authors: Duyck Wouter , Lagrou Evelyne , Gevers Wim , Fias Wim
Published: November 2007

Abstract. Earlier research with monolinguals and bilinguals showed that numbers may be named through both a semantic and a phonological route, depending on the number's language and format (Arabic or verbal), task demands, and naming language. The present study investigated the importance of the semantic route for the processing of a third representation of magnitude, namely Roman digits. Using an interference paradigm, we showed that the processing of Roman target digits is influenced by Arabic digit distractors, both in a naming task and a parity judgment task. Roman digits were processed faster if the target and distractor were of the same magnitude. If this was not the case, processing speed slowed down as the numerical distance between target and distractor increased. This strongly suggests that semantic access is mandatory when naming Roman digits. Implications are discussed for the number processing domain and for models of translation in bilinguals.
Viral dynamics in cryoconite holes on a high Arctic glacier (Svalbard)
Authors: Anesio Alexandre M. , Mindl Birgit , Laybourn‐Parry Johanna , Hodson Andrew J. , Sattler Birgit
Published: November 2007

Viruses are an abundant and dynamic constituent of microbial communities in aquatic ecosystems. In this study we characterized the abundance of viruses associated first with the bottom sediment and overlying water of cryoconite holes and second with shallow ice cores of two different glaciers in Svalbard. Viral abundances were ca. 10–100 times lower than the average for marine and freshwater ecosystems in temperate regions. Virus to bacterium ratios (VBR) (average > 10, range between 0.7 and 74 in the water and ice samples) and a strong positive correlation between viral and bacterial abundance (r = 0.93, p < 0.01, N = 57) indicate that viruses most probably play an important role in controlling bacterial mortality and hence biogeochemical cycling on glaciers. Samples taken along a transect from the glacier ablation area to proglacial ponds in its forefield showed that viral abundance increased in response to a higher host availability, which in turn probably resulted from an increase in temperature and higher mineral levels in the ponds. In a transplantation experiment, viruses from cryoconite holes were incubated with a bacterial community from a proglacial lake. Results from the transplantation experiment showed that viruses from cryoconite holes were able to infect bacteria from proglacial lakes and thus influence biogeochemical cycles across different glacial ecosystems. Our data therefore suggest that viruses in cryoconite holes may be able to infect a broad range of bacterial species.
The arctic freshwater system: Changes and impacts
Authors: White Daniel , Hinzman Larry , Alessa Lilian , Cassano John , Chambers Molly , Falkner Kelly , Francis Jennifer , Gutowski William J. , Holland Marika , Holmes R. Max , Huntington Henry , Kane Douglas , Kliskey Andrew , Lee Craig , McClelland James , Peterson Bruce , Rupp T. Scott , Straneo Fiamma , Steele Michael , Woodgate Rebecca , Yang Daqing , Yoshikawa Kenji , Zhang Tingjun
Published: November 2007

Dramatic changes have been observed in the Arctic over the last century. Many of these involve the storage and cycling of fresh water. On land, precipitation and river discharge, lake abundance and size, glacier area and volume, soil moisture, and a variety of permafrost characteristics have changed. In the ocean, sea ice thickness and areal coverage have decreased and water mass circulation patterns have shifted, changing freshwater pathways and sea ice cover dynamics. Precipitation onto the ocean surface has also changed. Such changes are expected to continue, and perhaps accelerate, in the coming century, enhanced by complex feedbacks between the oceanic, atmospheric, and terrestrial freshwater systems. Change to the arctic freshwater system heralds changes for our global physical and ecological environment as well as human activities in the Arctic. In this paper we review observed changes in the arctic freshwater system over the last century in terrestrial, atmospheric, and oceanic systems.
Scattering of an arbitrary plane wave by a dielectric wedge: Integral equations and fields near the edge
Authors: Marx Egon
Published: November 2007

The behavior of the field components near the edge has been shown to be that of the static fields, which is derived here without rigor for an infinite wedge. Fields scattered by a finite dielectric wedge illuminated by an arbitrary plane monochromatic wave are computed using either singular or hypersingular integral equations (SIEs or HIEs), derived by the single integral equation method. Field components are then computed near the edge of a finite wedge. Longitudinal components of the fields behave like constants, other components of the electric field behave like those in the transverse magnetic mode, and other components of the magnetic field behave like those in the transverse electric mode. Exceptions occur when approaching the wedge along the bisector. Boundary functions and transverse field components computed with SIEs rise more sharply than predicted approaching the edge after a range in which the agreement with those computed with HIEs is good.
Efficient integral equation formulation for inductive waveguide components with posts touching the waveguide walls
Authors: Pérez‐Soler F. J. , Quesada‐Pereira F. D. , Cañete Rebenaque D. , Pascual‐García J. , Alvarez‐Melcon A.
Published: November 2007

In this paper a surface integral equation technique is employed for the analysis of inductive waveguide problems containing metallic or dielectric objects of arbitrary shape, focusing on the case where these objects are connected to the waveguide walls. Using the extinction theorem, the main problem is split into two problems. In the first one the parallel plate waveguide Green's functions are used. Because of the choice of these functions, the side of the object touching the waveguide wall is not considered for discretization in a method of moments analysis. The second problem is applied inside the dielectric object, and uses the free space Green's functions. It is shown that an additional spatial image is needed to impose the proper boundary conditions for the fields on the side touching the waveguide wall in the original problem. Results show the importance of including this additional image in the formulation for the correct behavior of the fields. With the proposed technique, the paper explores some alternatives for designing specific filter responses using dielectric posts inside cavity filters. Comparisons with a commercial finite elements tool demonstrate the accuracy of the proposed integral equation formulation.
Importance of cold and dry surges in substantiating the NAM and ENSO relationship
Authors: Nakamura Tetsu , Tachibana Yoshihiro , Shimoda Haruhisa
Published: November 2007

We propose a possible mechanism for the influence of the Northern Hemisphere annular mode/Arctic Oscillation (NAM/AO) on westerly wind bursts (WWB). Using 26‐year reanalysis data, we statistically demonstrate and evidentially confirm that the NAM intensifies WWB through Asian cold and dry surges. Twin cyclones with anomalous westerlies and updrafts were dominant in the western tropical Pacific in positive NAM years. This structure was caused by the inflow of cold and dry advections associated with cold and dry surges, which excited anomalous heat transport from the western tropical Pacific Ocean. This thermodynamic structure is similar to that of the Matsuno‐Gill pattern. Observational evidence indicates that the surge associated with the NAM is a probable cause of El Niño outbreaks through the intensification of WWB, stemming from the WWB association with the Matsuno‐Gill pattern.
Avalanche mobility induced by the presence of an erodible bed and associated entrainment
Authors: Mangeney A. , Tsimring L. S. , Volfson D. , Aranson I. S. , Bouchut F.
Published: November 2007

The partial fluidization model developed by Aranson and Tsimring (2002) is used to simulate the spreading of a 2D circular cap of granular material over an erodible bed made of the same material. Numerical results show that the presence of even a very thin layer of granular material lying on the solid bed strongly increases the mobility of granular flows. Furthermore, as the thickness of the granular layer increases, the dynamics of the flowing mass changes from a decelerating avalanche to a traveling wave. Numerical simulation suggest that surges are generated if enough mass is entrained, increasing the energy of the flowing material and balancing the energy lost by friction.
Monitoring and predicting the 2007 U.S. drought
Authors: Luo Lifeng , Wood Eric F.
Published: November 2007

Severe droughts developed in the West and Southeast of the U.S. starting early in 2007. The development of the droughts is well monitored and predicted by our model‐based Drought Monitoring and Prediction System (DMAPS). Using the North America Land Data Assimilation System (NLDAS) realtime meteorological forcing and the Variable Infiltration Capacity (VIC) land surface model, DMAPS is capable of providing a quantitative assessment of the drought in near realtime. Using seasonal climate forecasts from NCEP's Climate Forecast System (CFS) as one input, DMAPS successfully predicted the evolution of the droughts several months in advance. The realtime monitoring and prediction of drought with the system will provide invaluable information for drought preparation and drought impact assessment at national and local scales.
Near‐infrared spectral mapping of Titan's mountains and channels
Authors: Barnes Jason W. , Radebaugh Jani , Brown Robert H. , Wall Steve , Soderblom Laurence , Lunine Jonathan , Burr Devon , Sotin Christophe , Le Mouélic Stephane , Rodriguez Sebastien , Buratti Bonnie J. , Clark Roger , Baines Kevin H. , Jaumann Ralf , Nicholson Phillip D. , Kirk Randolph L. , Lopes Rosaly , Lorenz Ralph D. , Mitchell Karl , Wood Charles A.
Published: November 2007

We investigate the spectral reflectance properties of channels and mountain ranges on Titan using data from Cassini's Visual and Infrared Mapping Spectrometer (VIMS) obtained during the T9 encounter (26 December 2005). We identify the location of channels and mountains using synthetic aperture radar maps obtained from Cassini's RADAR instrument during the T13 (30 April 2006) flyby. Channels are evident even in VIMS imaging with spatial resolution coarser than the channel size. The channels share spectral characteristics with Titan's dark blue terrain (e.g., the Huygens landing site) that is consistent with an enhancement in water ice content relative to the rest of Titan. We use this fact to measure widths of ∼1 km for the largest channels. Comparison of the data sets shows that in our study area within the equatorial bright spectral unit east of Xanadu, mountains are darker and bluer than surrounding smooth terrain. These results are consistent with the equatorial bright terrain possessing a veneer of material that is thinner in the regions where there are mountains and streambeds that have likely undergone more recent and extensive erosion. We suggest a model for the geographic relationship of the dark blue, dark brown, and equatorial bright spectral units based on our findings.
Mars Global Digital Dune Database and initial science results
Authors: Hayward Rosalyn K. , Mullins Kevin F. , Fenton Lori K. , Hare Trent M. , Titus Timothy N. , Bourke Mary C. , Colaprete Anthony , Christensen Philip R.
Published: November 2007

A new Mars Global Digital Dune Database (MGD3) constructed using Thermal Emission Imaging System (THEMIS) infrared (IR) images provides a comprehensive and quantitative view of the geographic distribution of moderate‐ to large‐size dune fields (area >1 km2) that will help researchers to understand global climatic and sedimentary processes that have shaped the surface of Mars. MGD3 extends from 65°N to 65°S latitude and includes ∼550 dune fields, covering ∼70,000 km2, with an estimated total volume of ∼3,600 km3. This area, when combined with polar dune estimates, suggests moderate‐ to large‐size dune field coverage on Mars may total ∼800,000 km2, ∼6 times less than the total areal estimate of ∼5,000,000 km2 for terrestrial dunes. Where availability and quality of THEMIS visible (VIS) or Mars Orbiter Camera narrow‐angle (MOC NA) images allow, we classify dunes and include dune slipface measurements, which are derived from gross dune morphology and represent the prevailing wind direction at the last time of significant dune modification. For dunes located within craters, the azimuth from crater centroid to dune field centroid (referred to as dune centroid azimuth) is calculated and can provide an accurate method for tracking dune migration within smooth‐floored craters. These indicators of wind direction are compared to output from a general circulation model (GCM). Dune centroid azimuth values generally correlate to regional wind patterns. Slipface orientations are less well correlated, suggesting that local topographic effects may play a larger role in dune orientation than regional winds.
Reversal of an immunity associated plant cell death program by the growth regulator auxin
Authors: Gopalan Suresh
Published: November 2007

One form of plant immunity against pathogens involves a rapid host programmed cell death at the site of infection accompanied by resistance, termed the hypersensitive response (HR). Here it is shown that the HR programmed cell death program initiated by the bacterial type III secretion system dependent proteinaceous elicitor harpin from Erwinia amylovora can be reversed till very late in the process by the plant growth regulator auxin. Early inhibition or late reversal of this cell death program does not affect marker genes tightly correlated with local and systemic resistance. Cross-regulation between cell death programs and growth regulators is prevalent in different kingdoms. Thus, the concept that cell death program can be reversed till late provides a framework for further investigation of such phenomena, in addition to having utility in choosing better targets and strategies for treating mammalian and agricultural diseases.
Insights into drug metabolism by cytochromes P450 from modelling studies of CYP2D6‐drug interactions
Authors: Maréchal J‐D , Kemp C A , Roberts G C K , Paine M J I , Wolf C R , Sutcliffe M J
Published: November 2007

The cytochromes P450 (CYPs) comprise a vast superfamily of enzymes found in virtually all life forms. In mammals, xenobiotic metabolizing CYPs provide crucial protection from the effects of exposure to a wide variety of chemicals, including environmental toxins and therapeutic drugs. Ideally, the information on the possible metabolism by CYPs required during drug development would be obtained from crystal structures of all the CYPs of interest. For some years only crystal structures of distantly related bacterial CYPs were available and homology modelling techniques were used to bridge the gap and produce structural models of human CYPs, and thereby obtain useful functional information. A significant step forward in the reliability of these models came seven years ago with the first crystal structure of a mammalian CYP, rabbit CYP2C5, followed by the structures of six human enzymes, CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2D6 and CYP3A4, and a second rabbit enzyme, CYP2B4. In this review we describe as a case study the evolution of a CYP2D6 model, leading to the validation of the model as an in silico tool for predicting binding and metabolism. This work has led directly to the successful design of CYP2D6 mutants with novel activity—including creating a testosterone hydroxylase, converting quinidine from inhibitor to substrate, creating a diclofenac hydroxylase and creating a dextromethorphan O‐demethylase. Our modelling‐derived hypothesis‐driven integrated interdisciplinary studies have given key insight into the molecular determinants of CYP2D6 and other important drug metabolizing enzymes.

British Journal of Pharmacology (2008) 153, S82–S89; doi:10.1038/sj.bjp.0707570; published online 19 November 2007
AS601245, a c‐Jun NH2‐terminal kinase (JNK) inhibitor, reduces axon/dendrite damage and cognitive deficits after global cerebral ischaemia in gerbils
Authors: Carboni S , Boschert U , Gaillard P , Gotteland J‐P , Gillon J‐Y , Vitte P‐A
Published: November 2007

Background and purpose.

Based on their proven ability, in animal models of stroke, to reduce damage to brain grey matter, many drugs have been tested in clinical trials but without success. Failure to save axons from injury and to protect functional outcome has been proposed as the major reason for this lack of success. We have previously demonstrated in two rodent models of cerebral ischaemia, that AS601245 (1,3‐benzothiazol‐2‐yl (2‐{[2‐(3‐pyridinyl) ethyl] amino}‐4 pyrimidinyl) acetonitrile), an inhibitor of the c‐Jun NH2‐terminal kinase (JNK), has neuroprotective properties. The aim of the present study was to further investigate if AS601245 in addition to its ability to protect neurons also could protect neurites and preserve memory after cerebral ischaemia, in gerbils.

Experimental approach.

Using immunohistochemical techniques and a behavioural test, we studied the effect of the compound AS601245 on neurodegeneration and cognitive deficits after global cerebral ischaemia in gerbils.

Key results.

At a dose of 80 mg kg−1, i.p., AS601245 reduced damage to neurites by 67% (P<0.001 versus controls) and activation of astrocytes by 84% (P<0.001 versus controls). In addition, AS601245 (80 mg kg−1, i.p.) prevented ischaemia‐induced impairment of memory in the inhibitory avoidance task model.

Conclusions and implications.

The present results suggest that AS601245 reduced damage to neurites and decreased astrogliosis following global ischaemia and also improved long‐term memory, supporting JNK inhibition as a promising therapeutic strategy for ischaemic insults to the CNS.

British Journal of Pharmacology(2008)153, 157–163; doi:10.1038/sj.bjp.0707574; published online 19 November 2007
[Pt(O,O′‐acac)(γ‐acac)(DMS)], a new Pt compound exerting fast cytotoxicity in MCF‐7 breast cancer cells via the mitochondrial apoptotic pathway
Authors: Muscella A , Calabriso N , Fanizzi F P , De Pascali S A , Urso L , Ciccarese A , Migoni D , Marsigliante S
Published: November 2007

Background and purpose:

We showed previously that a new Pt complex containing an O,O′‐chelated acetylacetonate ligand (acac) and a dimethylsulphide in the Pt coordination sphere, [Pt(O,O′‐acac)(γ‐acac)(DMS)], induces apoptosis in HeLa cells. The objective of this study was to investigate the hypothesis that [Pt(O,O′‐acac)(γ‐acac)(DMS)] is also cytotoxic in a MCF‐7 breast cancer cell line relatively insensitive to cisplatin, and to gain a more detailed analysis of the cell death pathways.

Experimental approach:

Cells were treated with Pt compounds and cytotoxicity tests were performed, together with Western blotting of various proteins involved in apoptosis. The mitochondrial membrane potential was assessed by fluorescence microscopy and spectrofluorometry and the Pt bound to cell fractions was measured by atomic absorption spectrometry.

Key results:

In contrast to cisplatin, the cytotoxicity of [Pt(O,O′‐acac)(γ‐acac)(DMS)] correlated with cellular accumulation but not with DNA binding. Also, the Pt content in DNA bases was considerably higher for cisplatin than for [Pt(O,O′‐acac)(γ‐acac)(DMS)], thus excluding DNA as a target of [Pt(O,O′‐acac)(γ‐acac)(DMS)]. [Pt(O,O′‐acac)(γ‐acac)(DMS)] exerted high and fast apoptotic processes in MCF‐7 cells since it provoked: (a) mitochondria depolarization; (b) cytochrome c accumulation in the cytosol; (c) translocation of Bax and truncated‐Bid from cytosol to mitochondria and decreased expression of Bcl‐2; (d) cleavage of caspases ‐7 and ‐9, and PARP degradation; (e) chromatin condensation and DNA fragmentation.

Conclusions and implications:

[Pt(O,O′‐acac)(γ‐acac)(DMS)] is highly cytotoxic for MCF‐7 cells, cells relatively resistant to many chemotherapeutic agents, as it activates the mitochondrial apoptotic pathway. Hence, [Pt(O,O′‐acac)(γ‐acac)(DMS)] has the potential to provide us with new opportunities for therapeutic intervention.

British Journal of Pharmacology (2008) 153, 34–49; doi:10.1038/sj.bjp.0707576; published online 19 November 2007
Analysis of sphingosine 1‐phosphate receptors involved in constriction of isolated cerebral arteries with receptor null mice and pharmacological tools
Authors: Salomone S , Potts E M , Tyndall S , Ip P C , Chun J , Brinkmann V , Waeber C
Published: November 2007

Background and purpose:

Sphingosine 1‐phosphate (S1P) selectively and potently constricts isolated cerebral arteries, but this response has not been pharmacologically characterized.

Experimental approach:

The receptor subtype(s) involved in S1P‐induced cerebrovascular constriction were characterized using genetic (S1P2 and S1P3 receptor null mice) and pharmacological tools (phospho‐FTY720, a S1P1/3/4/5 receptor agonist; SEW2871, a S1P1 receptor agonist, JTE‐013, a S1P2 receptor antagonist, VPC23019, a S1P1/3 receptor antagonist). Isolated basilar or peripheral (femoral, mesenteric resistance) arteries, from either rat or mouse, were studied in a wire myograph.

Key results:

S1P concentration‐dependently constricted basilar artery in rat, wild‐type (WT) and S1P2 null mice, but barely affected vascular tone in S1P3 null mice. Vasoconstriction to U46619 (a thromboxane analogue) or to endothelin‐1 did not differ between WT, S1P2 and S1P3 null mice. JTE‐013 inhibited not only S1P‐induced vasoconstriction, but also KCl‐, U46619‐ and endothelin‐1‐induced constriction. This effect was observed in WT as well as in S1P2 null mice. VPC23019 increased the concentration‐dependent vasoconstriction to S1P in both rat and mouse basilar arteries with intact endothelium, but not in rat basilar artery without endothelium. Phospho‐FTY720 concentration‐dependently constricted rat basilar arteries, but not femoral or mesenteric resistance arteries, while SEW2871 did not induce any response in the same arteries.

Conclusions and implications:

S1P constricts cerebral arteries through S1P3 receptors. The purported S1P2 receptor antagonist JTE‐013 does not appear to be selective, at least in rodents. Enhancement of S1P‐induced contraction by VPC23019 might be related to blockade of S1P1 receptors and NO generation.

British Journal of Pharmacology (2008) 153, 140–147; doi:10.1038/sj.bjp.0707581; published online 19 November 2007
Endocannabinoids and cannabinoid receptors in ischaemia–reperfusion injury and preconditioning
Authors: Pacher P , Haskó G
Published: November 2007

Ischaemia–reperfusion (I/R) is a pivotal mechanism of organ injury during stroke, myocardial infarction, organ transplantation and vascular surgeries. Ischaemic preconditioning (IPC) is a potent endogenous form of tissue protection against I/R injury. On the one hand, endocannabinoids have been implicated in the protective effects of IPC through cannabinoid CB1/CB2receptor‐dependent and ‐independent mechanisms. However, there is evidence suggesting that endocannabinoids are overproduced during various forms of I/R, such as myocardial infarction or whole body I/R associated with circulatory shock, and may contribute to the cardiovascular depressive state associated with these pathologies. Previous studies using synthetic CB1receptor agonists or knockout mice demonstrated CB1receptor‐dependent protection against cerebral I/R injury in various animal models. In contrast, several follow‐up reports have shown protection afforded by CB1receptor antagonists, but not agonists. Excitedly, emerging studies using potent CB2receptor agonists and/or knockout mice have provided compelling evidence that CB2receptor activation is protective against myocardial, cerebral and hepatic I/R injuries by decreasing the endothelial cell activation/inflammatory response (for example, expression of adhesion molecules, secretion of chemokines, and so on), and by attenuating the leukocyte chemotaxis, rolling, adhesion to endothelium, activation and transendothelial migration, and interrelated oxidative/nitrosative damage. This review is aimed to discuss the role of endocannabinoids and CB receptors in various forms of I/R injury (myocardial, cerebral, hepatic and circulatory shock) and preconditioning, and to delineate the evidence supporting the therapeutic utility of selective CB2receptor agonists, which are devoid of psychoactive effects, as a promising new approach to limit I/R‐induced tissue damage.

British Journal of Pharmacology(2008)153, 252–262; doi:10.1038/sj.bjp.0707582; published online 19 November 2007
Comment on “Bohmian mechanics with complex action: A new trajectory-based formulation of quantum mechanics” [J. Chem. Phys. 125, 231103 (2006)]
Authors: Sanz A. S. , Miret-Artés S.
Published: November 2007

With this Comment, we would like to provide a general discussion on two important issues arising from a recent work by Goldfarb et al. [J. Chem. Phys.125, 231103 (2006)], which we consider to be of broad interest to the Chemical Physics community. First we introduce a discussion on trajectory-based formalisms associated with the quantum Hamilton-Jacobi approach. Then, we stress the special interest relying on how the term locality should be used in quantum mechanics, in particular, when dealing with trajectory-based formulations of this theory.
Response to “Comment on ‘Bohmian mechanics with complex action: A new trajectory-based formulation of quantum mechanics’ ” [J. Chem. Phys. 127, 197101 (2007)]
Authors: Goldfarb Yair , Degani Ilan , Tannor David J.
Published: November 2007

In their comment, Sanz and Miret-Artés (SMA) describe previous trajectory-based formalisms based on the quantum Hamilton-Jacobi (QHJ) formalism. In this reply, we highlight our unique contributions: the identification of the smallness of the quantum force in the complex QHJ and its solution using complex trajectories. SMA also raise the question of how the term locality should be used in quantum mechanics. We suggest that at least certain aspects of nonlocality can depend on the method used to solve the problem.
Realistic laser focusing effect on electron acceleration in the presence of a pulsed magnetic field
Authors: Gupta Devki Nandan , Suk Hyyong , Hur Min Sup
Published: November 2007

As we know, for a significant electron energy gain, a fast electron should be injected into the highest intensity region of the laser focus. Such intensities may be achieved in the laboratory by tight focusing of a laser. For a tight focused laser beam, it is necessary to consider all field components the arise due to the tight focusing of the laser beam, when the waist of the laser beam is of the order of the laser wavelength. By using the accurate field components of a tightly focused laser beam, we investigate the electron acceleration in the presence of a pulsed magnetic field. Our study shows that the electron energy gain during laser acceleration is found to be considerably higher.
Strong localization effect in temperature dependence of violet-blue emission from ZnO nanoshells
Authors: Zeng Haibo , Li Zhigang , Cai Weiping , Liu Peisheng
Published: November 2007

Violet-blue photoluminescence of Zn/ZnO core/shell nanoparticles, induced by laser ablation in liquid, was observed. The emission band shows an abnormal red first and then blueshift with temperature increasing from 8 to 300 K and abnormal narrowing at the temperature range from 30 to 130 K. Such temperature-dependent behaviors can be well described by localization model on interstitial zinc defect on both peak energy and peak width evolutions, reflecting the strong localization effect from the special microstructure. This work will be beneficial to understanding of the physical origins of the violet-blue emission in nanostructured ZnO, and extending its optical and electronic applications.
Nonlinear optical response of wave packets on quantized potential energy surfaces
Authors: Ishida Kunio , Aiga Fumihiko , Misawa Kazuhiko
Published: November 2007

We calculated the dynamics of nuclear wave packets in coupled electron-vibration systems and their nonlinear optical responses. We found that the quantized nature of the vibrational modes is observed in pump-probe spectra particularly in weakly interacting electron-vibration systems such as cyanine dye molecules. Calculated results based on a harmonic potential model and molecular orbital calculations are compared with experimental results, and we also found that the material parameters regarding the geometrical structure of potential energy surfaces are directly determined by accurate measurement of time-resolved spectra.
Turbulent anti-resistivity and the zonal magnetic field dynamo in drift-ballooning turbulence
Authors: Kleva Robert G. , Guzdar Parvez N.
Published: November 2007

The effect of turbulent fluctuations on the zonal (flux surface averaged) magnetic field in drift-ballooning turbulence is shown to be equivalent to a turbulent anti-resistivity. The flux surface average of the convective nonlinearity in Ohm’s law is proportional to the flux surface average of the current. The coefficient of proportionality can be defined as a turbulent resistivity ηturb. The correlation of the flux surface average of the convective nonlinearity with the negative of the flux surface average of the current is nearly 100%. Because the convective nonlinearity is correlated with the negative of the current, and not the current, the turbulent resistivity is negative. The magnitude of ηturb is virtually identical to the magnitude of the collisional resistivity η, but opposite in sign, so that the total resistivity ηtotal=η+ηturb is nearly zero. The effect of the fluctuations is to balance the effect of collisional resistive diffusion. As a result, while the energy in the zonal flow increases to a large value as the fluctuations grow and saturate, the energy in the zonal magnetic field remains very small.
Effect of ambient, excitation intensity and wavelength, and chemical structure on photodegradation in polysilanes
Authors: Sharma Asha , Katiyar Monica , Deepak  , Shukla Sanjeev K. , Seki Shu
Published: November 2007

The photodegradation of a copolymer based on diphenyl and methylphenyl polysilane has been investigated by measuring the changes occurring in photoluminescence (PL) and absorption in solution and film form. In the solution, the degradation mechanism is photoscission of the Si–Si bonds, confirmed by gel permeation chromatography. In the films also, this mechanism exists but with a reduced rate due to cage effect. We are reporting an additional degradation mechanism, observed in the films, which is not sensitive to the environment. It is attributed to formation of defects or traps in the deformed segments of polysilane chain in film. Photodegradation rate is slower for the shorter wavelength emission/absorption due to occurrence of energy transfer from shorter to longer segments. In addition to degradation, the copolymer films exhibit an initial enhancement in PL intensity, which is attributed to the changes in chain conformation caused by heat generation during irradiation. We have also investigated the effect of chemical structure on photodegradation behavior by also evaluating poly(n-butylphenylsilane), poly(n-hexylphenylsilane), poly(n-octylphenylsilane), and poly[bis(p-n-butylphenyl)silane] polysilanes. The addition of bulky alkyl or aryl groups on both sides leads to improved stability with respect to photoscission, but degradation due to defect or trap creation persists even in solution, which is attributed to the differences in conformation of these polysilanes. Based on the experimental evidence, we present a physical model for degradation mechanisms operating in polysilanes.
1.54
μ
m
photoluminescence of Er-doped GeOx thin films
Authors: Ardyanian M. , Rinnert H. , Vergnat M.
Published: November 2007

Amorphous Er-doped GeOx alloys were prepared by evaporation on substrates maintained at 100°C. Photoluminescence experiments were carried out in the visible and near-infrared ranges. The Er-related peak was observed at 1.54μm at room temperature in the as deposited samples. The PL of erbium is characterized by a weak temperature quenching and by a decay time in the millisecond range. The luminescence of Er is a decreasing function of the annealing temperature. Undoped GeOx layers showed a PL band at 800nm, attributed to defects states, which disappeared when Er is introduced. The intense Er-related luminescence was assigned to an indirect excitation process from defects states to Er ions.