bluuebunny/crossref_metadata_2025 huggingface dataset:
Endothelin mediated contraction of equine laminar veins
Authors: Keen J. A. , Hillier C. , Mcgorum B. C. , Nally J. E.
Published: September 2008

Reasons for performing study: Endothelin‐1 (ET‐1) may be a key mediator in the pathogenesis of laminitis, but endothelin‐mediated responses in the venous microcirculation of the equine foot have yet to be fully characterised.

Objectives: To characterise the response of equine laminar veins to ET‐1 and evaluate the ET‐1 receptor subtypes that mediate this response.

Methods: Small veins (150–500 μm) draining the equine digital laminae from healthy horses and ponies subjected to euthanasia at an abattoir were investigated using wire myography. Concentration response curves were constructed for ET‐1 in the presence of ETA(BQ123) and ETB(BQ788) receptor antagonists, and L‐NAME, a nitric oxide synthase blocker. The selective ETBreceptor agonist BQ3020 was investigated alone and following incubation with L‐NAME, with or without BQ788.

Results: Endothelin‐1 contraction of laminar veins was significantly inhibited by BQ123 but not by BQ788. In the presence of L‐NAME, sensitivity of laminar veins to ET‐1 was enhanced 4‐fold, and further addition of BQ788 did not alter this increased sensitivity. BQ3020 induced no venoconstriction; however, in the presence of L‐NAME, it caused contraction of veins with approximately 30% of the efficacy of ET‐1. The action of BQ3020 in the presence of L‐NAME was abolished by BQ788.

Conclusions: Both ETAand ETBreceptors are involved in the net tonic response to ET‐1 in normal laminar veins. A population of ETBreceptors may be present on the vascular endothelium and on smooth muscle of laminar veins, and the action of ET‐1 at these 2 sites is likely to be approximately equal and opposite.

Potential relevance: Our results clarify the function of the ET‐1 receptor subtypes in laminar veins from healthy horses. Further study of ET‐1 receptors in laminitic horses is therefore warranted.
Quantitative morphology of the equine laminar junction in relation to capsule shape in the forehoof of Standardbreds and Thoroughbreds
Authors: Thomason J. J. , Faramarzi B. , Revill Ms. A. , Sears W.
Published: September 2008

Reasons for performing study: Differences in hoof morphology have largely been underappreciated in the literature until recently, and it is these that hold the key to interpreting functional adaptation in the hoof.

Hypotheses: Primary laminar morphology correlates with hoof capsule shape; and breeds with different hoof shapes and loadings show different patterns of correlation.

Methods: Seventeen measurements of capsule shape and 3 of primary epidermal laminae (PEL) morphology (spacing, orientation and curvature) were made on right and left front hooves from 27 Standardbred and 25 Thoroughbred horses, and tested for breed differences. Three laminar variables (spacing, orientation and curvature) were measured on each hoof for samples of 25 PEL in 5 circumferential and 4 proximodistal locations. Pairwise correlations of capsular and laminar measurements were compared within breeds. Significant correlations were mapped onto the 20 sampling sites.

Results: Capsule shape differed significantly between breeds in 7 measurements and in a multivariate test. Between breeds, PEL differed in orientation and spacing primarily at the medial quarters and heels, and in curvature at both quarters (P<0.05). Significant correlations between several pairs of capsule and laminar variables were found at sample locations that differed markedly between breeds.

Conclusions: Laminar morphology, hoof capsule shape and correlations between them differ between Standardbreds and Thoroughbreds. These results support the concept that remodelling of PEL is, at least in part, stimulated and directed by varying stress or strain levels in the laminar junction.

Potential relevance: Understanding the biological responses of hoof tissues to stress should add to the ability to prevent lameness involving the hoof and maintain its health.
In vitro and in vivo modulation of the equine immune response by parapoxvirus ovis
Authors: Horohov D. W. , Breathnach C. C. , Sturgill T. L. , Rashid C. , Stiltner J. L. , Strong D. , Nieman N. , Holland R. E.
Published: September 2008

Reason for performing study: While immune modulators are used routinely in equine medicine, their mechanism of action is not always known.

Objectives: To determine the effect of a commercial preparation of inactivated parapoxvirus ovis (Orf virus; PPVO) on cytokine gene expression by equine peripheral blood mononuclear cells (PBMC) both in vitro and in vivo.

Methods: PBMC were prepared from 6 mixed‐breed yearlings and cultured in vitro with PPVO with or without Concanavalin A (Con A) for 24 h. Effects on the expression of IFNα, IFNβ, IFNγ, TNFα and IL‐18 were analysed by real time quantitative PCR (RT‐PCR). In addition, 12 yearling horses were treated with PPVO and whole blood RNA samples were prepared at regular intervals to assess effects on in vivo cytokine gene expression. Six of those yearlings were later treated with saline and served as treatment controls. Nine additional yearlings were injected intradermally with a single dose and their injection sites biopsied at 24 and 48 h for cytokine expression.

Results: In vitro culture of PBMC with PPVO led to a significant increase in IFNα and IFNβ gene expression compared to mock‐stimulated cultures. In addition, expression of IFNγ and TNFα was significantly higher in PBMC stimulated with PPVO and Con A, than those stimulated with Con A alone. No changes were observed in IL‐18 gene expression in vitro. Treatment of horses with a 3‐dose regimen of PPVO resulted in elevation of IFNγ gene expression, which was detected 24 h after the first dose and declined thereafter. Intradermal inoculation led to increased expression of IFNγ along with IFNβ, IL‐15 and IL‐18.

Conclusions: Together these results indicate that PPVO stimulated IFNγ production both in vitro and in vivo. Increased cytokine expression could account for its immunomodulatory activity.

Potential relevance: The absence of adverse reactions and clear indications of increased expression of cytokine gene expression supports previous clinical uses for this immune modulator in those situations when increased expression of IFNγ is warranted.
Computed tomographic anatomy of the temporomandibular joint in the young horse
Authors: RODRÍGUEZ M. J. , LATORRE R. , LÓPEZ‐ALBORS O. , SOLER M. , AGUIRRE C. , VÁZQUEZ J. M. , QUEROL M. , AGUT A.
Published: September 2008

Reasons for performing study: The equine temporomandibular joint (TMJ) and its surrounding structures can be difficult to investigate in cases with a clinical problem related to the region. Little previous attention has been given either to a computed tomographic (CT) imaging protocol for the joint or an interpretation of the structures displayed in CT images of the normal joint.

Objectives: To provide a CT atlas of the normal cross‐sectional anatomy of the equine TMJ using frozen and plastinated sections as anatomical reference.

Methods: Eight TMJs from 4 immature pure‐bred Spanish horses were examined by helical CT. Scans were processed with a detailed algorithm to enhance bony and soft tissue. Transverse CT images were reformatted into sagittal and dorsal planes. Transverse, sagittal and dorsal cryosections were then obtained, photographed and plastinated. Relevant anatomic structures were identified in the CT images and corresponding anatomical sections.

Results: In the CT images, a bone window provided excellent bone detail, however, the soft tissue components of the TMJ were not as well visualised using a soft tissue window. The articular cartilage was observed as a hyperattenuating stripe over the low attenuated subchondral bone and good delineation was obtained between cortex and medulla. The tympanic and petrous part of the temporal bone (middle and inner ear) and the temporohyoid joint were seen in close proximity to the TMJ.

Conclusions: Helical CT provided excellent images of the TMJ bone components to characterise the CT anatomy of the normal joint.

Potential relevance: Detailed information is provided that may be used as a reference by equine veterinarians for the CT investigation of the equine TMJ and serve to assist them in the diagnosis of disorders of the TMJ and related structures (middle and inner ear). The study was performed at an immature stage and further studies of mature individuals are required in order to confirm that the clinical interpretation is not affected by changes occurring with age.
Frequency of the severe combined immunodeficiency disease gene among horses in Morocco
Authors: PIRO M. , BENJOUAD A. , TLIGUI N. S. , ALLALI K. EL , KOHEN M. EL , NABICH A. , OURAGH L.
Published: September 2008

Severe combined immunodeficiency disease (SCID) of horses is an autosomal, recessive hereditary disease occurring among Arabian or crossbred Arabian horses. The genetic defect responsible was previously identified as a 5‐base pair deletion in the gene encoding the catalytic subunit of the DNA dependant protein kinase (DNA‐PKcs). This study was carried out to determine the frequency of SCID and identify horses carrying the gene for SCID among Arabian and Arabian crossbred stallions and mares in Morocco using a DNA‐based test. Twenty‐one horses were SCID carriers: 14 (7%) Arabians, 6 (4%) Arab‐Barbs and one (3.3%) Anglo‐Arab. After analysing their genealogy, 3 imported stallions were identified that disseminated the mutant gene of DNA‐PKcs in Morocco.
Concurrent atypical myoglobinuria and colon displacement in a filly
Authors: Sherlock C. E. , Mair T. S.
Published: September 2008

An 18‐month‐old pony filly was examined for acute colic and abdominal distension. The signs of colic failed to resolve following analgesic treatment. At exploratory laparotomy, a right dorsal displacement of the large colon was identified and corrected. On recovery from anaesthesia, the pony developed signs of widespread myopathy, confirmed by serum biochemistry evaluations. Myopathy consistent with atypical myoglobinuria was confirmedpost mortem.
The use of veterinary medicinal products in equine practices in The Netherlands: Balancing between the law and good veterinary practice
Authors: Loomans J. B. A. , Kranenburg L. C. , Weeren P. R. van , Barneveld A.
Published: September 2008

This study investigates the present situation with respect to the use and abuse of (veterinary) medicinal products (VMPs) by equine practitioners and endeavours to substantiate the perceived discrepancies and friction between the availability of VMPs, legislation in force, code of Good Veterinary Practice and reality of day‐today equine practice. It can be concluded that practising equine medicine in The Netherlands using only authorised equine VMPs is impossible. In most cases the ‘cascade’ or list of essential substances is needed to legitimise the use or, even worse, the use is not legitimised at all. Existing differences between European Union member states in the outcome of procedures for obtaining a marketing authorisation for the same product is seen as an obstacle for the availability and development of equine VMPs needed for safeguarding the future of a professional equine veterinary healthcare.
Ultrasonographic examination of the proximal tendon of thebiceps brachii: Technique and reference images
Authors: Pasquet H. , Coudry V. , Denoix J.‐M.
Published: September 2008

Ultrasonography of the shoulder is of interest in the diagnosis of proximal forelimb lameness. The proximal tendon of thebiceps brachii(PTBB) and its associated structures are frequently injured and should be included in the routine ultrasonographic examination of the shoulder.

This paper describes a complete ultrasonographic procedure for examining the bicipital apparatus, on transverse and longitudinal scans, from the insertion of the PTBB on the supraglenoid tubercle to the muscle body below the intertubercular sulcus.
Magnetic resonance imaging features of an extranodal T cell rich B cell lymphoma in the pharyngeal mucosa in a horse
Authors: Jakesova V. , Konar M. , Gerber V. , Brachelente C. , Howard J. , Tessier C.
Published: September 2008

An 11‐year‐old Warmblood gelding was presented for inspiratory stridor and dysphagia. Based on history and clinical examination, a solitary mass localised in the oropharynx was suspected. Due to its inaccessibility and defensive behaviour of the horse, it was difficult to visualise this mass either by upper airway endoscopy or by oral examination and the conventional imaging methods (radiology and ultrasound) provided only limited information. Fine needle aspiration cytology was suggestive of lymphoma, but the exact localisation and the extent of tissue infiltration of the tumour could only be defined by magnetic resonance imaging (MRI). MRI has proved to be a very useful diagnostic tool in equine lameness investigation and, as this case illustrates, it has considerable diagnostic potential for soft tissue examination of the equine head.
Diagnosis and surgical management of a subchondral bone cyst within the intermediate tubercle of the humerus in a horse
Authors: Arnold C. E. , Chaffin M. K. , Honnas C. M. , Walker M. A. , Heite W. K.
Published: September 2008

The case of a horse with a subchondral bone cyst in the lateral slope of the intermediate humeral tubercle is presented. Diagnosis was complicated by the unusual location and subsequent challenge in imaging the cyst. Endoscopic debridement resulted in a good outcome.
Computed tomography assisted repair of a central tarsal bone slab fracture in a horse
Authors: Kelmer G. , Wilson D. A. , Essman S. C.
Published: September 2008

A 13‐year‐old Quarter Horse gelding was presented for repair of a central tarsal bone fracture. Radiographs showed a single large nondisplaced sagittal slab fracture; however, computed tomography (CT) revealed an additional small, displaced central tarsal bone fragment. The complex fracture was repaired, under the same anaesthetic period as the CT examination, using the CT hard copies images, intraoperative fluoroscopy and radiographs. The horse recovered well and after rehabilitation showed no residual lameness at work. Computed tomography was instrumental in achieving precise screw placement and successful fracture repair.
A retrospective study comparing conservative and surgical treatments of open comminuted fractures of the fourth metatarsal bone in horses
Authors: Sherlock C. E. , Archer R. M.
Published: September 2008

The proximal third of metatarsal IV is predisposed to open comminuted fractures due to its superficial and prominent position and controversy exists regarding the most appropriate management for this type of fracture.

Fifty‐three horses treated for open comminuted fractures of the proximal third of metatarsal IV were selected for study from 6 equine hospitals across England. Comparisons were made between the 21 horses treated conservatively and the 32 horses treated surgically.

Horses treated conservatively at referral centres had comparable rates of survival, rates of return to full work and convalescent periods but a significantly lower cost than those treated surgically.

The results of this study suggest that aggressive conservative therapy may be indicated in open comminuted fractures of the proximal third of metatarsal IV.
Hyperkalaemic periodic paralysis‐like syndrome in a Criollo Argentino horse
Authors: Diakakis N. , Spanoudes K. , Dessiris A.
Published: September 2008

Hyperkalaemic periodic paralysis (HYPP) is a relatively new genetic disease that, so far, appears to be confined to descendants of the American Quarter Horse Impressive, a stallion identified as the link between the pedigrees of all affected horses, and that predominantly affects Quarter Horses but also Paint horses, Appaloosas and Palominos. This study suggests that an episode of muscle weakness, which was reported in a Criollo Argentino genetically unrelated to Impressive, was related to marked hyperkalaemia. The symptoms in this case were reproducible following a KCI challenge test although DNA testing for HYPP was negative. Based on these findings, a diagnosis of a HYPP‐like syndrome was made.
A singular case of traumatic total hoof capsule avulsion
Authors: de Gresti A. , Zani D. D. , D'Arpe L. , Scandella M.
Published: September 2008

Total, full thickness hoof wall avulsion is rare in horses. Sometimes complications such as fracture of the distal phalanx, osteomyelitis, septic arthritis and degenerative joint disease have been reported. Limiting motion at the affected site and hoof stabilisation are essential to obtain a good hoof regeneration.

This case report reviews the clinical features including diagnostic techniques (radiographic examination and venography) of a Quarter Horse filly presented with a complete and full‐thickness traumatic hoof capsule avulsion complicated by an open fracture of the third phalanx. A transfixation casting technique was performed followed after one month by 2 short limb casts applied for 2 months each. Twenty‐four months after trauma the foot had completely regrown. The dorsal aspect of the hoof wall appears to be remarkably shorter compared to the heels. From a radiographic viewpoint, the lateral aspect of the left hind foot shows diffuse bone remodelling and a deformed distal phalanx.
Overview of the use of antimicrobials for the treatment of bacterial infections in horses
Authors: Haggett E. F. , Wilson W. D.
Published: September 2008

Use of antimicrobial drugs is central to the treatment of primary and secondary bacterial infection in horses. When selecting an antimicrobial to treat confirmed or suspected bacterial infection multiple factors should be considered, including: the likely infectious agent; distribution and dosage of selected drugs; mechanisms of action; and potential side effects. Many of these issues will be covered in subsequent articles in this series. The aim of this paper is to aid the clinician in the rational selection of antimicrobials by reviewing the mode of action, spectrum of activity, pharmacokinetics, pharmacodynamics, indications and potential side effects of the main classes of antimicrobial drugs. Extralabel use of drugs is common in veterinary medicine due to a lack of licensed products. This increases the importance of a thorough understanding of antimicrobials and their possible adverse effects.
Disseminated large granular lymphoma in a horse
Authors: Sheats M. K. , van Wetter A. J. N. J. , Snyder L. A. , Jones S. L.
Published: September 2008

A 21‐year‐old pony gelding presented for a 5 week history of diarrhoea, inappetance, progressive weight loss and lethargy. Differential diagnoses for chronic diarrhoea and weight loss in horses include: chronic salmonellosis, sand enteropathy, enterolith, parasitism (strongylosis, cyathostomiasis), NSAID induced ulcerative colitis, inflammatory bowel disease (granulomatous, lymphocytic‐plasmacytic or eosinophilic enterocolitis), gastrointestinal neoplasia (lymphosarcoma, squamous cell carcinoma), antibiotic associated clostridial overgrowth, altered diet or bacterial fermentation, peritonitis,Strongylus vulgarisinduced arteriopathy (now quite rare) and abdominal mass or abscess. In this gelding,ante mortemdiagnosis of CD3+intestinal large granular lymphoma was made via cytology of abdominal fluid and immunohistochemistry of a rectal muscle biopsy. This report details the clinical, cytological and immunophenotypic findings of a case of large granular lymphoma in a horse.
Collateral desmitis of the distal interphalangeal joint in conjunction with concurrent ossification of the cartilages of the foot in nine horses
Authors: Mair T. S. , Sherlock C. E.
Published: September 2008

The purpose of this study was to describe the frequency of occurrence of severe ossification of the collateral cartilages (sidebone) coexistent with collateral desmitis of the distal interphalangeal joint (DIPJ) in lame horses. Sidebone was diagnosed and graded on standard radiographs and soft tissue injuries of the foot were diagnosed using standing low‐field magnetic resonance imaging (MRI). Of 15 horses with forelimb lameness and severe sidebone, 9 had evidence of concurrent collateral desmitis of the DIPJ. All 15 horses had damage to other structures (including the deep digital flexor tendon, distal sesamoidean impar ligament, collateral sesamoidean ligament, navicular bone and distal phalanx) within the affected feet as identified on MRI. The clinical and pathophysiological significance of concurrent collateral desmitis of the DIPJ and sidebone is currently uncertain. However, this study shows that injuries to multiple structures within the foot are common and that collateral desmitis of the distal interphalangeal joint is frequently seen in lame horses in conjunction with severe ossification of the collateral cartilages.
Hoch- und spätmittelalterliche Siedlungsräume im südlichen Bayerischen Wald
Authors: Haversath Johann-Bernhard
Published: September 2008

The colonization of the southern Bavarian Forest during the late Middle Ages took a greater and more different course than the known results of historical and territorial investigations suggested. The settlement-activities at the beginning of the late Middle Ages had two effects: on the one hand the settled area was extended into the forest (frontier-line), on the other hand the earlier settled districts became more and more compact (interior colonization). The planned settlements (linear and place-villages with so called Hofacker-/Gelängeflur) arose only at places, where new land was systematically colonized after clearances. Here the so-called Hofacker-/Gelängeflur proved to be a system of allotments which was very weil adapted to the necessities of hilly ground and agriculture. The model of type-succession does not seem to be suitable for showing the development of colonization in the southern Bavarian Forest. The complex reality will find a better explanation if we suggest a process of innovation. Such a model embraces the regular settlements with garden allotments at second-best places, as weil as the regular settlements with so-called Hofacker-/Gelängeflur in the so far unsettled districts.
Street Youth, Unemployment, and Crime: Is It That Simple? Using General Strain Theory to Untangle the Relationship
Authors: Baron Stephen W.
Published: September 2008

Researchers have called for greater attention to be paid to the variables linking unemployment to crime. In particular, it has been suggested that people's interpretation of their labour market situation plays a large role in shaping their responses to it. Utilizing general strain theory, this research examines the role that unemployment plays in the criminal behaviour of 400 homeless street youths. Of particular interest is the way that these youths interpret their labour market experiences and how together these interpretations and experiences influence criminal behaviour. Findings reveal that the effect of unemployment on crime is mediated and moderated primarily by other variables. In particular, unemployment is conditioned by external casual attributions that lead to anger over unemployment, which in turn leads to crime. The direct effect of unemployment on crime is moderated by monetary dissatisfaction and minimal employment searches. Anger over unemployment is also the result of negative subjective interpretations of economic situations and a continued attachment to the labour market. In addition, these negative subjective perceptions, the lack of state support, a decrease in social control, and prolonged homelessness lead to greater participation in criminal activities directly. Criminal involvement is also encouraged by peers, deviant values, and a lack of fear of punishment. Findings are discussed and suggestions for future research are offered.
Factors Influencing Police Attitudes towards Extrajudicial Measures under the Youth Criminal Justice Act
Authors: Marinos Voula , Innocente Nathan
Published: September 2008

Extrajudicial measures under the Youth Criminal Justice Act require police to reorient their thinking about how to respond to youth. The act provides specific structure and guidance to police about the appropriateness of extrajudicial measures and does not preclude its use when a youth received one in the past. The emphasis on accountability and proportionality suggests that police ought to be driven by the seriousness of the youth's offending behaviour and much less by the youth's record. Drawing from a sample of 70 police officers from five jurisdictions within Ontario, our surveys (N = 70) and in-depth interviews (N = 64) with police reveal that they place relatively heavy weight on prior police contact of any kind (past extrajudicial measure or finding of guilt) and that this has a significant influence on their attitudes towards diverting youth for minor offences like mischief and shoplifting. The results are analyzed within the context of literature on police attitudes and decision making to divert in Canada.
Mortality patterns among petroleum refinery and chemical plant workers
Authors: Marsh Gary M. , Enterline Philip E. , McCraw Dorothy
Published: September 2008

A historical cohort study was conducted to evaluate the mortality experience of 6,831 employees of the Shell Oil Company, Deer Park, Texas, petroleum refinery and chemical plant with emphasis on cancer mortality. Subjects were all workers with potential plant exposure who were employed for at least 3 months during 1948‐72. Vital status was determined as of 12/31/83 for 98% of the cohort and death certificates were obtained for 95.4% of 1,180 observed deaths. The statistical analyses excluded 159 female study members. For all causes of death combined, all cancers combined, and for most of the nonmalignant disease categories examined, there were deficits in mortality among refinery workers, chemical plant workers, and workers with experience in both areas. These deficits were generally most pronounced for chemical plant workers. An analysis of specific cancer sites revealed patterns of increased risk suggestive of a possible relationship between occupational exposures in the refinery and lympho‐reticulosarcoma. Patterns of increased risk were also observed among chemical plant workers for a category of lymphopoietic tissue cancers, including multiple myeloma, myelofibrosis, polycythemia vera, and certain non‐Hodgkin's lymphomas. Some very limited evidence of a possible workplace association was also found among refinery workers for leukemia and cancers of the central nervous system and biliary passages/liver. No evidence was found of an increased risk for cancer of the respiratory system or stomach or for malignant melanoma. A work history review of all suspect cancer excesses failed to identify any common work areas, job assignments, or exposure potentials, although the lack of detailed data on specific chemical exposures precluded accurate assessments of exposure‐response.
Training a hierarchical classifier using inter document relationships
Authors: Gauch Susan , Chandramouli Aravind , Ranganathan Shankar
Published: September 2008

Text classifiers automatically classify documents into appropriate concepts for different applications. Most classification approaches use flat classifiers that treat each concept as independent, even when the concept space is hierarchically structured. In contrast, hierarchical text classification exploits the structural relationships between the concepts. In this article, we explore the effectiveness of hierarchical classification for a large concept hierarchy. Since the quality of the classification is dependent on the quality and quantity of the training data, we evaluate the use of documents selected from subconcepts to address the sparseness of training data for the top‐level classifiers and the use of document relationships to identify the most representative training documents. By selecting training documents using structural and similarity relationships, we achieve a statistically significant improvement of 39.8% (from 54.5–76.2%) in the accuracy of the hierarchical classifier over that of the flat classifier for a large, three‐level concept hierarchy.
A Google Scholar h‐index for journals: An alternative metric to measure journal impact in economics and business
Authors: Harzing Anne‐Wil , van der Wal Ron
Published: September 2008

We propose a new data source (Google Scholar) and metric (Hirsch's h‐index) to assess journal impact in the field of economics and business. A systematic comparison between the Google Scholar h‐index and the ISI Journal Impact Factor for a sample of 838 journals in economics and business shows that the former provides a more accurate and comprehensive measure of journal impact.
Numerical experiments on dynamo action in sheared and rotating turbulence
Authors: Yousef T. A. , Heinemann T. , Rincon F. , Schekochihin A. A. , Kleeorin N. , Rogachevskii I. , Cowley S. C. , McWilliams J. C.
Published: September 2008

Numerical simulations of forced turbulence in elongated shearing boxes are carried out to demonstrate that a nonhelical turbulence in conjunction with a linear shear can give rise to a mean‐field dynamo. Exponential growth of magnetic field at scales larger than the outer (forcing) scale of the turbulence is found. Over a range of values of the shearing rateSspanning approximately two orders of magnitude, the growth rate of the magnetic field is proportional to the imposed shear,γ ∝ S, while the characteristic spatial scale of the field islB∝ S–1/2. The effect is quite general: earlier results for the nonrotating case by Yousef et al. (2008) are extended to shearing boxes with Keplerian rotation; it is also shown that the shear dynamo mechanism operates both below and above the threshold for the fluctuation dynamo. The apparently generic nature of the shear dynamo effect makes it an attractive object of study for the purpose of understanding the generation of magnetic fields in astrophysical systems. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Saturation of the magnetorotational instability at large Elsasser number
Authors: Jamroz B. , Julien K. , Knobloch E.
Published: September 2008

The magnetorotational instability is investigated within the shearing box approximation in the large Elsasser number regime. In this regime, which is of fundamental importance to astrophysical accretion disk theory, shear is the dominant source of energy, but the instability itself requires the presence of a weaker vertical magnetic field. Dissipative effects are weaker still but not negligible. The regime explored retains the condition that (viscous and ohmic) dissipative forces do not play a role in the leading order linear instability mechanism. However, they are sufficiently large to permit a nonlinear feedback mechanism whereby the turbulent stresses generated by the MRI act on and modify the local background shear in the angular velocity profile. To date this response has been omitted in shearing box simulations and is captured by a reduced pde model derived here from the global MHD fluid equations using multiscale asymptotic perturbation theory. Results from numerical simulations of the reduced pde model indicate a linear phase of exponential growth followed by a nonlinear adjustment to algebraic growth and decay in the fluctuating quantities. Remarkably, the velocity and magnetic field correlations associated with these algebraic growth and decay laws conspire to achieve saturation of the angular momentum transport. The inclusion of subdominant ohmic dissipation arrests the algebraic growth of the fluctuations on a longer, dissipative time scale. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Can turbulent plane‐shear flows support large‐scale dynamos?
Authors: Kitchatinov L. L.
Published: September 2008

Turbulent plane‐shear flow is found to show same basic effects of mean‐fieldMHD as rotating turbulence. In particular, the mean electromotive force (EMF) includes highly anisotropic turbulent diffusion and alpha‐effect. Only magnetic diffusion remains for spatially‐uniform turbulence. The question is addressed whether in this case a self‐excitation of a magnetic field by so‐called sher‐current dynamo is possible and the quasilinear theory provides a negative answer. The streamaligned component of the EMF has the sign opposite to that required for dynamo. If, however, the turbulence is not uniform across the flow direction then a dynamo‐activeα‐effect emerges. The critical magnetic Reynolds number for the alpha‐shear dynamo is estimated to be slightly above ten. Possibilities for cross‐checking theoretical predictions with MHD experiments are discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Results of a modified PROMISE experiment
Authors: Stefani F. , Gerbeth G. , Gundrum Th. , Szklarski J. , Rüdiger G. , Hollerbach R.
Published: September 2008

The PROMISE experiment relies on the fact that the critical Reynolds number for the appearance of the magnetorotational instability (MRI) in liquid metal flows drastically decreases when the purely axial magnetic field is replaced by a helical one. We report the results of a modified version of this experiments in which the radial electrical boundary conditions are changed. Special focus is laid on the role of the radial jet region where the two Ekman vortices from the top and the bottom meet each other. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Furfural: Hemicellulose/xylosederived biochemical
Authors: Mamman Ajit Singh , Lee Jong‐Min , Kim Yeong‐Cheol , Hwang In Taek , Park No‐Joong , Hwang Young Kyu , Chang Jong‐San , Hwang Jin‐Soo
Published: September 2008

Hemicellulose, the second, most common polysaccharide in nature constitutes approximately 20—35% of lignocellulosic biomass. Effective utilization of biomass, hitherto underutilized, is gaining tremendous importance for the production of energy, fuels, and chemicals. Amongst the vast array of chemicals derived from lignocellulosics, furfural is the key chemical that finds wide applications in oil refining, plastics, pharmaceutical and agrochemical industries. There is no synthetic route for the production of furfural. A few conventional technologies currently in practice for its separation and subsequent isolation are appropriately reviewed. Major disadvantages associated with processes currently used for the production of furfural based on acid‐catalyzed hydrolysis have been discussed. A need to develop a process which is devoid of all the shortcomings associated with conventional process is emphasized. Several important aspects of chemistry underlying the acid hydrolysis of xylose are discussed. The importance of myriad pre‐treatment steps involved to surmount the physical and chemical barriers and to liberate xylose from the confines of acid‐resistant layer of lignin has been emphasized. New developments in the production of furfural from cyclodehydration of xylose using solid acid catalysts in the recent past have been reviewed appropriately in present communication. Finally, the production of furfural and furfuryl alcohol, their domestic market and export in China deserve some coverage and therefore have appropriately been discussed as well. © 2008 Society of Chemical Industry and John Wiley & Sons, Ltd
Intraneural ganglion cyst: A 200‐year‐old mystery solved
Authors: Spinner Robert J. , Vincent Jean‐François , Wolanskyj Alexandra P. , Scheithauer Bernd W.
Published: September 2008

We describe the first reported case of an intraneural ganglion cyst, an ulnar (“cubital”) intraneural cyst, which, on literature review, dated to 1810. For over 80 years, its original brief description by Beauchêne was wrongly attributed to Duchenne, effectively making the reference and specimen inaccessible to scrutiny. Fortunately, the intact cyst had been safely housed in the Musée Dupuytren, Paris, France, thus permitting its examination. Although originally described as a “serous” cyst, our present understanding of the anatomy of the ulnar nerve and of peripheral nerve pathology allowed us to reinterpret it as a mucin‐filled, elbow‐level, ulnar intraneural ganglion cyst. In addition to its description as a fusiform cystic enlargement of the nerve, we documented similar enlargement of a lumen‐bearing branch, the articular branch at the level of the elbow. Based on our assessment of the specimen and with a modern perspective, we concluded that the origin of the cyst was from the postero‐medial aspect of the elbow joint and that its fluid content, having dissected through a capsular defect, followed the path of the articular branch into the parent ulnar nerve. The purpose of this report is to clarify historical misconceptions regarding the pathogenesis of this controversial entity. Clin. Anat. 21:611–618, 2008. © 2008 Wiley‐Liss, Inc.
Structure, Magnetic Properties, Polarized Neutron Diffraction, and Theoretical Study of a Copper(II) Cubane
Authors: Aronica Christophe , Chumakov Yurii , Jeanneau Erwann , Luneau Dominique , Neugebauer Petr , Barra Anne‐Laure , Gillon Béatrice , Goujon Antoine , Cousson Alain , Tercero Javier , Ruiz Eliseo
Published: September 2008

The paper reports the synthesis, X‐ray and neutron diffraction crystal structures, magnetic properties, high field–high frequency EPR (HF‐EPR), spin density and theoretical description of the tetranuclear CuII complex [Cu4L4] with cubane‐like structure (LH2=1,1,1‐trifluoro‐7‐hydroxy‐4‐methyl‐5‐aza‐hept‐3‐en‐2‐one). The simulation of the magnetic behavior gives a predominant ferromagnetic interaction J1 (+30.5 cm−1) and a weak antiferromagnetic interaction J2 (−5.5 cm−1), which correspond to short and long Cu–Cu distances, respectively, as evidence from the crystal structure (ℋ︁=−${{{}\mathrel{\mathop{\sum{}}\limits_{i\char62 j}}{}}}$2JijŜiŜj). It is in agreement with DFT calculations and with the saturation magnetization value of an S=2 ground spin state. HF‐EPR measurements at low temperatures (5 to 30 K) provide evidence for a negative axial zero‐field splitting parameter D (−0.25±0.01 cm−1) plus a small rhombic term E (0.025±0.001 cm−1, E/D = 0.1). The experimental spin distribution from polarized neutron diffraction is mainly located in the basal plane of the CuII ion with a distortion of yz‐type for one CuII ion. Delocalization on the ligand (L) is observed but to a smaller extent than expected from DFT calculations.
A Dinuclear Iron Complex Based on Parallel Malonate Binding Sites: Cooperative Activation of Dioxygen and Biomimetic Ligand Oxidation
Authors: Siewert Inke , Limberg Christian , Demeshko Serhiy , Hoppe Elke
Published: September 2008

A ligand that offers two parallel malonate binding sites linked by a xanthene backbone, namely, Xanthmal2−, has been utilised to synthesise dinuclear FeII complex [Fe2(Xanthmal)2] (1). The reactivity of 1 in contact with O2 was investigated at −40 °C and room temperature. After activation of O2 through interaction with both iron centres the ligand is oxidised: at the Cα position monooxygenation and peroxide formation occur, partially accompanied by CC bond cleavage to yield α‐keto ester groups. To reveal mechanistic details investigations concerning 1) peroxide decomposition, 2) the reactivity of a corresponding mononuclear complex, 3) the influence of monooxygenation of the ligand on the reactivity and 4) product formation in dependence on time were carried out. The results can be explained by postulating formation of high‐valent Fe intermediates and ligand‐to‐metal electron transfer, and the mechanistic scheme derived includes several steps that mimic the (suggested) functioning of non‐heme iron enzymes. In agreement with this proposal, ligand oxidation can also be performed catalytically. Furthermore, we show that via a competitive route [(Xanthmal)2Fe2O] (2) is formed, which is unreactive towards O2 and thus is a dead end with respect to ligand oxidation. Both compounds 1 and 2 were fully characterised, and their properties are discussed.
Determination of the Electrophilicity Parameters of Diethyl Benzylidenemalonates in Dimethyl Sulfoxide: Reference Electrophiles for Characterizing Strong Nucleophiles
Authors: Kaumanns Oliver , Lucius Roland , Mayr Herbert
Published: September 2008

The second‐order rate constants of the reactions of nine substituted diethyl benzylidenemalonates 1 a–i with the carbanions 2 a–e have been determined spectrophotometrically in dimethyl sulfoxide (DMSO). Product studies show that the nucleophiles attack regioselectively at the electrophilic CC double bond of the Michael acceptors to form the carbanionic adducts 4. The correlation log k(20 °C)=s(N+E) allows the determination of the electrophilicity parameters E for the electrophiles 1 a–i from the rate constants determined in this work and the previously published N and s parameters for the nucleophiles 2 a–e. The electrophilicities E for compounds 1 a–i cover a range of six units (−17.7>E>−23.8) and correlate excellently with Hammett's substituent constants σp. The title compounds are roughly ten orders of magnitude less reactive than analogously substituted benzylidene Meldrum's acids, their cyclic analogues. Due to their low reactivities, compounds 1 a–i are suitable reference electrophiles for determining the reactivities of highly reactive nucleophiles, such as carbanions with 16<N<30.
First Principles Investigation of Noncovalent Complexation: A [2.2.2]‐Cryptand Ion‐Binding Selectivity Study
Authors: Su Joe W. , Burnette Ronald R.
Published: September 2008

A first principles methodology, aimed at understanding the roles of molecular conformation and energetics in host–guest binding interactions, is developed and tested on a system that pushes the practical limits of ab initio methods. The binding behavior between the [2.2.2]‐cryptand host (4,7,13,16,21,24‐hexaoxa‐1,10‐diaza‐bicyclo[8.8.8]hexacosane) and alkali metal cations (Li+, Na+, and K+) in gas, water, methanol, and acetonitrile is characterized. Hartree–Fock and density functional theory methods are used in concert with crystallographic information to identify gas phase, energy‐minimized conformations. Gas phase free energies of binding, with vibrational contributions, are compared to solution‐state binding constants through relative binding selectivity analysis. Calculated relative binding free energies qualitatively correlated with solution state experiments only after gas phase metal desolvation is considered. The B3LYP exchange–correlation functional improves theoretical correlations with experimental relative binding free energies. The relevance of gas phase calculations towards understanding binding in condensed phases is discussed. Natural bond orbital methods highlights previously unidentified intramolecular and intermolecular M+(222) chemistries, such as an intramolecular n′O→σ*CH hydrogen bond.
Metamorphosis and adult development of the mushroom bodies of the red flour beetle, Tribolium castaneum
Authors: Zhao X. , Coptis V. , Farris S. M.
Published: September 2008

The insect mushroom bodies play important roles in a number of higher processing functions such as sensory integration, higher level olfactory processing, and spatial and associative learning and memory. These functions have been established through studies in a handful of tractable model systems, of which only the fruit fly Drosophila melanogaster has been readily amenable to genetic manipulations. The red flour beetle Tribolium castaneum has a sequenced genome and has been subject to the development of molecular tools for the ready manipulation of gene expression; however, little is known about the development and organization of the mushroom bodies of this insect. The present account bridges this gap by demonstrating that the organization of the Tribolium mushroom bodies is strikingly like that of the fruit fly, with the significant exception that the timeline of neurogenesis is shifted so that the last population of Kenyon cells is born entirely after adult eclosion. Tribolium Kenyon cells are generated by two large neuroblasts per hemisphere and segregate into an early‐born δ lobe subpopulation followed by clear homologs of the Drosophila γ, α′/β′ and α/β lobe subpopulations, with the larval‐born cohorts undergoing dendritic reorganization during metamorphosis. BrdU labeling and immunohistochemical staining also reveal that a proportion of individual Tribolium have variable numbers of mushroom body neuroblasts. If heritable, this variation represents a unique opportunity for further studies of the genetic control of brain region size through the control of neuroblast number and cell cycle dynamics. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008.
Adolescent development of neuron structure in dentate gyrus granule cells of male syrian hamsters
Authors: Zehr Julia L. , Nichols Liana R. , Schulz Kalynn M. , Sisk Cheryl L.
Published: September 2008

Hippocampal function, including spatial cognition and stress responses, matures during adolescence. In addition, hippocampal neuron structure is modified by gonadal steroid hormones, which increase dramatically at this time. This study investigated pubertal changes in dendritic complexity of dentate gyrus neurons. Dendrites, spines, and cell bodies of Golgi‐impregnated neurons from the granule cell layer were traced in pre‐, mid‐, and late‐pubertal male Syrian hamsters (21, 35, and 49 days of age). Sholl analysis determined the number of intersections and total dendritic length contained in concentric spheres set at 25‐μm increments from the soma. Spine densities were quantified separately in proximal and distal segments of a subset of neurons used for the Sholl analysis. We found that the structure of neurons in the lower, but not upper, blade of the dentate gyrus changed during adolescence. The lower, infrapyramidal blade showed pruning of dendrites close to the cell body and increases in distal dendritic spine densities across adolescence. These data demonstrate that dentate gyrus neurons undergo substantial structural remodeling during adolescence and that patterns of maturation are region specific. Furthermore, these changes in dendrite structure, which alter the electrophysiological properties of granule cells, are likely related to the adolescent development of hippocampal‐dependent cognitive functions such as learning and memory, as well as hippocampus‐mediated stress responsivity. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008.
Dual inhibition of proteasomal and lysosomal proteolysis ameliorates autoimmune central nervous system inflammation
Authors: Fissolo Nicolas , Kraus Marianne , Reich Michael , Ayturan Miriam , Overkleeft Herman , Driessen Christoph , Weissert Robert
Published: September 2008

Multiple sclerosis (MS) is a detrimental disease of the central nervous system (CNS) leading to long‐term disability. In the course of animal models of multiple sclerosis (experimental autoimmune encephalomyelitis), we find enhanced activity of proteasome subunits b1i, b2, b2i and b5 in the CNS. We demonstrate that pharmacological inhibition of the proteasome by bortezomib ameliorates experimental autoimmune encephalomyelitis in mice and rats in prophylactic and therapeutic treatment with reduced numbers of T‐cells secreting proinflammatory cytokines. The anti‐inflammatory effect of proteasome inhibition was accompanied by reduced NF‐jB activity in the CNS and lymphoid organs. The combined inhibition of proteasomes and lysosomal proteases involved in major histocompatibility complex II antigen presentation further improved therapeutic efficacy. We suggest proteasome inhibition alone or in combination with inhibition of lysosomal proteases as a novel therapeutic strategy against inflammation‐induced neurodegeneration in the CNS. We demonstrate the impact of the proteasome and lysosomal proteases on development of autoimmunity.
Geoadditive models for the analysis of the spatial distribution of soil salinity in a Sardinia coastal area
Authors: Cafarelli Barbara , Pollice Alessio
Published: September 2008

The use of geoadditive models is proposed to analyse the spatial distribution of the sodium absorption ratio (SAR) of a citrus groves cultivated area, in order to ascertain the factors influencing its extreme salinization. Geoadditive models are considered as an evolution of universal kriging, allowing explicit consideration of the linear and nonlinear relations with relevant explanatory variables as well as the spatial correlation described by a standard spatial autocorrelation function. Copyright © 2008 John Wiley & Sons, Ltd.