bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of self‐gated cine MRI retrospective cardiac synchronization algorithms
Authors: Nijm Grace M. , Sahakian Alan V. , Swiryn Steven , Carr James C. , Sheehan John J. , Larson Andrew C.
Published: September 2008

Purpose

To determine whether improved self‐gating (SG) algorithms can provide superior synchronization accuracy for retrospectively gated cine MRI.

Materials and Methods

First difference, template matching, and polynomial fitting algorithms were implemented to improve the synchronization of MRI data using cardiac SG signals. Cine datasets were acquired during short‐axis, two‐, three‐, and four‐chamber cardiac MRI scans. The root‐mean‐square (RMS) error of SG synchronization positions compared to detected R‐wave positions were calculated along with the mean square error (MSE) and peak signal‐to‐noise ratio (PSNR) comparing SG to electrocardiogram (ECG)‐gated images. Overall image quality was also compared by two expert reviewers.

Results

RMS errors were highest for the first difference method for all orientations. Improvements for both template matching and cubic polynomial fitting methods were significant for two‐, three‐, and four‐chamber scans. MSE values were lower and PSNR were significantly higher for the cubic method compared to the first difference method for all orientations. Reviewers scored the images to be of comparable quality.

Conclusion

Template matching and polynomial fitting improved the accuracy of cardiac cycle synchronization for two‐, three‐, and four‐chamber scans; improvements in SG synchronization accuracy were reflected in improvements in analytical image quality. Implementation of robust postprocessing algorithms may bring SG approaches closer to clinical utilization. J. Magn. Reson. Imaging 2008;28:767–772. © 2008 Wiley‐Liss, Inc.
Wave diffraction by a strip with first and second kind boundary conditions: the real wave number case
Authors: Castro L. P. , Kapanadze D.
Published: September 2008

We prove unique existence of solution for a class of plane wave diffraction problems by a strip with first and second kind boundary conditions. This is done in a Bessel potential spaces framework, and for a real (noncomplex) wave number. At the end, results about the regularity (and data dependence) of the solution are exhibited upon the initial setting and the boundary parameters. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On Kummer extensions of the power series field
Authors: Tornero José M.
Published: September 2008

In this paper we study the Kummer extensions K ′ of a power series field K = k ((X1, …, Xr)), where k is an algebraically closed field of arbitrary characteristic, with special emphasis in the case where K ′ is generated by a Puiseux power series. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Existence of a non‐reflexive embedding with birational Gauss map for a projective variety
Authors: Fukasawa Satoru , Kaji Hajime
Published: September 2008

We study the relationship between the generic smoothness of the Gauss map and the reflexivity (with respect to the projective dual) for a projective variety defined over an algebraically closed field. The problem we discuss here is whether it is possible for a projective variety X in ℙN to re‐embed into some projective space ℙM so as to be non‐reflexive with generically smooth Gauss map. Our result is that the answer is affirmative under the assumption that X has dimension at least 3 and the differential of the Gauss map of X in ℙN is identically zero; hence the projective varietyX re‐embedded in ℙM yields a negative answer to Kleiman–Piene's question: Does the generic smoothness of the Gauss map imply reflexivity for a projective variety? A Fermat hypersurface in ℙN with suitable degree in positive characteristic is known to satisfy the assumption above. We give some new, other examples of X in ℙN satisfying the assumption. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Arens multiplication on Banach algebras related to locally compact semigroups
Authors: Maghsoudi S. , Nasr–Isfahani R. , Rejali A.
Published: September 2008

Let S be a locally compact semigroup, let ω be a weight function on S, and let Ma (S, ω) be the weighted semigroup algebra of S. Let L∞0 (S;Ma (S, ω)) be the C*‐algebra of allMa (S, ω)‐measurable functions g on S such that g /ω vanishes at infinity. We introduce and study an Arens multiplication on L∞0 (S;Ma (S, ω))* under which Ma (S, ω) is a closed ideal. We show that the weighted measure algebra M (S, ω) plays an important role in the structure of L∞0 (S;Ma (S, ω))*. We then study Arens regularity of L∞0 (S;Ma (S, ω))* and ist relation with Arens regularity of Ma (S, ω), M (S, ω) and the discrete convolution algebra ℓ1(S, ω). As the main result, we prove that L∞0 (S;Ma (S, ω))* is Arens regular if and only if S is finite, or S is discrete and Ω is zero cluster. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A regularity criterion for the dissipative quasi-geostrophic equations
Authors: Dong Hongjie , Pavlović Nataša
Published: September 2008

We establish a regularity criterion for weak solutions of the dissipative quasi-geostrophic equations (with dissipation

(−\mathrm{\Delta })^{\gamma / 2}

,

0 < \gamma ⩽1

). More precisely, we show that if

\theta \in L_{t}^{r_{0}}((0,T);B_{p,\infty }^{\alpha }(\mathbb{R}^{2}))

with

\alpha = \frac{2}{p} + 1−\gamma + \frac{\gamma }{r_{0}}

is a weak solution of the 2D quasi-geostrophic equation, then

\theta

is a classical solution in

(0,T] \times \mathbb{R}^{2}

. This result extends the regularity result of Constantin and Wu [P. Constantin, J. Wu, Regularity of Hölder continuous solutions of the supercritical quasi-geostrophic equation, Ann. I. H. Poincaré – AN (2007), doi:] to scaling invariant spaces.
Finding new families of rank-one convex polynomials
Authors: Pedregal Pablo , Bandeira Luís
Published: September 2008

We introduce a method to find, in a systematic way, rank-one convex polynomials. We show how it works in several examples. It can also be applied to convexity along general cones.
Shifting the Sterile Processing Department Paradigm: A Mandate for Change
Authors: Swanson Scott C.
Published: September 2008

STERILE PROCESSING DEPARTMENT (SPD) staff members have the difficult task of processing complicated instrumentation, containing costs, and managing limited resources; and how they face these challenges has a direct effect on patient care.

RECENT TECHNOLOGICAL ADVANCES require SPD staff members to be more knowledgeable about what instrument trays are used together and the conditions in which they are used to help prevent costly delays in processing.

THIS ARTICLE EXPLORES how one health care system was successful in facing these challenges by implementing a solid orientation and education program. AORN J 88 (August 2008) 241–247. © AORN, Inc, 2008.
Controlled‐Substance Returns in the Operating Suite
Authors: Sharer Kevin B.
Published: September 2008

DRUG DIVERSION is an ongoing problem in health care settings. The potential for drug diversion incidents in the perioperative area is high because of the availability of narcotics and other controlled substances and the stresses of working in this environment.

THE FLOW OF CONTROLLED SUBSTANCES traditionally has been monitored by various accounting systems, but these systems can be inaccurate because the returned medications rarely are tested to verify that they have not been diluted or replaced. Returned medications are not routinely tested because of the expense and time involved.

ENHANCED PHOTOEMISSION SPECTROSCOPY is one technology that can validate returned medications quickly and inexpensively. AORN J 88 (August 2008) 249–252. © AORN, Inc, 2008.
Evaluating the Evidence: Guidelines
Authors: Hanson Diane , Hoss Brenda L. , Wesorick Bonnie
Published: September 2008

GUIDELINES ARE COLLECTIONS of practical information that assist with clinical decision making. Evidence‐based guideline development includes a critique of the quality and an evaluation of the strength of published evidence.

EVOLUTION FROM opinion‐based to evidence‐based guidelines is incomplete in many of the organizations that author them, so perioperative nurses must become skillful at critiquing guideline development methodologies and clinical content.

THE AGREE INSTRUMENT is useful for evaluating guideline development. Nurses have access to evidence‐based guidelines registered online through the National Guideline Clearinghouse. AORN J 88 (August 2008) 184–196. © AORN, Inc, 2008.
Using Servant Leadership to Facilitate Healing After a Drug Diversion Experience
Authors: Ramer Lynne Marie
Published: September 2008

ALTHOUGH MUCH HAS BEEN WRITTEN about substance abuse in nursing, little attention has been paid to the reaction of a nurse's coworkers after he or she has been caught diverting drugs.

THE REMAINING STAFF MEMBERS may enter into a grieving process, which can have a serious effect on the delivery of patient care and staff satisfaction.

DEVOTING TIME AND ENERGY to addressing the challenges faced by staff members after a drug diversion experience is essential to reestablishing equilibrium in the department.

USING THE SERVANT LEADERSHIP MODEL, managers can exemplify the characteristics of commitment, persuasion, awareness, and foresight to facilitate the grieving process and solidify staff cohesion to help ensure quality patient care. AORN J 88 (August 2008) 253–258. © AORN, Inc, 2008.
Impaired activation of caspase cascade during cell death induced by newly synthesized singlet oxygen generator, 1‐buthylnaphthalene‐4‐propionate endoperoxide
Authors: Otsu Kaoru , Sato Kazuaki , Sato Michihiko , Ono Hideyu , Ohba Yoshihiro , Katagata Yohtaro
Published: September 2008

Endoperoxides of naphthalene derivatives generate singlet oxygen under physiological conditions. Here we have synthesized a new endoperoxide of a naphthalene derivative, 1‐buthylnaphthalene‐4‐propionate endoperoxide (BNPE), and studied its cytotoxic properties on HepG2 and HaCaT cells. BNPE induced cell death at much lower concentration than 1‐methylnaphthalene‐4‐propionate endoperoxide (MNPE) and naphthalene dipropionate endoperoxide (NDPE). A positive correlation exists between the amount of endoperoxide incorporated into cells and its cytotoxic ability. The cytotoxic effect of BNPE was attenuated by α‐tocopherol but not by sodium azide. In contrast, the effects of MNPE and NDPE were attenuated by both α‐tocopherol and sodium azide. The caspase cascade in cells treated with endoperoxide was impaired. Caspase activity in a soluble protein fraction were inhibited similarly by the above three endoperoxides. These results suggest an abortive apoptotic pathway due to the suppression of caspase activation is a general feature of cell death induced by singlet oxygen.
Rat mesenchymal stem cells increase tyrosine hydroxylase expression and dopamine content in ventral mesencephalic cells in vitro
Authors: Jin Guang‐Zhen , Cho Su‐Jin , Choi Eu‐Gene , Lee Young‐S. , Yu Xian‐Feng , Choi Kap‐Seong , Yee Sung‐Tae , Jeon Jin‐Tae , Kim Myeong‐Ok , Kong Il‐Keun
Published: September 2008

Mesenchymal stem cells (MSCs) are pluripotent adult stem cells. It has been shown that MSCs secrete neurotrophic factors involving nerve growth factor (NGF) and brain‐derived neurotrophic factor (BDNF). Also, these neurotrophic factors can upregulate tyrosine hydroxylase (TH) gene expression in PC12 cells and neural stem cells. Here, we investigated the effect of co‐culturing rat E13.5 ventral mesencephalic cells (VMCs) with MSCs from rat bone marrow on TH expression and dopamine (DA) content. The study consisted of 3 groups: MSC, VMC and a combined MSC + VMC group. All groups were cultured in serum‐free neuro‐basal medium for 3 days. Thereafter, each group was analyzed by RT‐PCR, western blotting, and HPLC. The co‐culture group showed a higher expression at TH and DA than the VMC group. However, TH and DA were not present in the MSC group. These observations suggest that MSCs could be an alternative source for treating neurodegenerative diseases such as Parkinson's disease (PD).
Simultaneous use of electrochemistry and chemiluminescence to detect reactive oxygen species produced by human neutrophils
Authors: Shleev Sergey , Wetterö Jonas , Magnusson Karl‐Eric , Ruzgas Tautgirdas
Published: September 2008

A novel approach for the simultaneous optical and electrochemical detection of biologically produced reactive oxygen species has been developed and applied. The set‐up consists of a luminol‐dependent chemiluminescence assay combined with two amperometric biosensors sensitive to superoxide anion radicals (O2−) and hydrogen peroxide (H2O2), respectively. The method permits direct, real‐time in vitro determination of both extra‐ and intracellular O2− and H2O2 produced by human neutrophil granulocytes. The rate of O2− production by stimulated neutrophils was calculated to about 10−17 mol s−1 per single cell. With inhibited NADPH oxidase, a distinct extracellular release of H2O2 instead of O2− was obtained from stimulated neutrophils with the rate of about 3 · 10−18 mol s−1 per single cell. When the H2O2 release was discontinued, fast H2O2 utilisation was observed. Direct interaction with and possibly attachment of neutrophils to redox protein‐modified gold electrodes, resulted in a spontaneous respiratory burst in the population of cells closely associated to the electrode surface. Hence, further stimulation of human neutrophils with a potent receptor agonist (fMLF) did not significantly increase the O2− sensitive amperometric response. By contrast, the H2O2 sensitive biosensor, based on an HRP‐modified graphite electrode, was able to reflect the bulk concentration of H2O2, produced by stimulated neutrophils and would be very useful in modestly equipped biomedical research laboratories. In summary, the system would also be appropriate for assessment of several other metabolites in different cell types, and tissues of varying complexity, with only minor electrode modifications.
Comparison of the endogenous IK currents in rat hippocampal neurons and cloned Kv2.1 channels in CHO cells
Authors: Liu Mingna , Gong Bo , Qi Zhi
Published: September 2008

The Kv2.1 potassium channel is a principal component of the delayed rectifier IK current in the pyramidal neurons of cortex and hippocampus. We used whole‐cell patch‐clamp recording techniques to systemically compare the electrophysiological properties between the native neuronal IK current of cultured rat hippocampal neurons and the cloned Kv2.1 channel currents in the CHO cells. The slope factors for the activation curves of both currents obtained at different prepulse holding potentials and holding times were similar, suggesting similar voltage‐dependent gating. However, the half‐maximal activation voltage for IK was ∼20 mV more negative than the Kv2.1 channel in CHO cells at a given prepulse condition, indicating that the neuronal IK current had a lower threshold for activation than that of the Kv2.1 channel. In adddition, the neuronal IK showed a stronger holding membrane potential and holding time‐dependence than Kv2.1. The Kv2.1 channel gave a U‐shaped inactivation, while the IK current did not. The IK current also had much stronger voltage‐dependent inactivation than Kv2.1. These results imply that the neuronal factors could make Kv2.1 channels easier to activate. The information obtained from these comparative studies help elucidate the mechanism of molecular regulation of the native neuronal IK current in neurons.
Stimulation of dorsal root ganglion neurons activity by pancreatic cancer cell lines
Authors: Li Jun‐Hui , Ma Qing‐Yong , Shen Su‐Gang , Hu Heng‐Tong
Published: September 2008

Stimulation of mice dorsal root ganglion neurons (DRGNs) activity by human pancreatic cancer (PanCa) cell line Mia PaCa‐2 and its potential molecule mechanism has been investaged. DRGNs were cultured alone or along with the MIA PaCa‐2. The effects of MIA PaCa‐2 to DRGNs were determined by neurofilament (NF) immunocytochemical and Nissl staining. ELISA was used to detect the concentration of insulin‐like growth factor‐1 (IGF‐1) in the culture supernatant. Cyton size, neurite outgrowth and neuronal activity in the experimental group were greater than in the control groups. However, the concentration of IGF‐1 in the supernatants was not significantly different from those in the blank and non‐cultured medium groups. In the presence of MIA PaCa‐2 cell line, cyton size, neurite outgrowth and neuronal activity were enhanced, which may provide more routes for the invasion of cancer cells along nerves.
Compression of the trigeminal ganglion produces prolonged nociceptive behavior in rats
Authors: Ahn Dong K. , Lim Eun J. , Kim Byung C. , Yang Gwi Y. , Lee Min K. , Ju Jin S. , Han Seung R. , Bae Yong C.
Published: September 2008

The present study is the first demonstration of prolonged nociceptive behavior in the trigeminal region following compression of the trigeminal ganglion in rats. Experiments were carried out on male Sprague–Dawley rats mounted onto a stereotaxic frame under pentobarbital sodium anesthesia. For compression of the trigeminal ganglion, a 4% agar solution (8μl) was injected into the trigeminal ganglion through a stainless steel injector (24 gauge), which extended 2mm beyond the end of a guide cannula (21 gauge). Following agar injection, the injector and guide cannula were removed. In the control group, rats were sham operated without agar injection. Air‐puff thresholds (mechanical allodynia), pin prick responses (mechanical hyperalgesia), and spontaneous scratching behavior were examined 3 days before surgery and at 3, 7, 10, 14, 17, 21, 24, 30, and 40 days after surgery. Data were analyzed using a repeated measures ANOVA followed by multiple group comparisons using the LSD post‐hoc test. Air‐puff thresholds significantly decreased after compression of the trigeminal ganglion. Mechanical allodynia was established within 3 days and lasted beyond postoperative day 24. Mechanical hyperalgesia was also evident 3 days after compression and persisted until the 40th postoperative day. Although mechanical allodynia and hyperalgesia appeared bilaterally, the ipsilateral side was significantly more sensitive. Intraperitoneal treatment with carbamazepine significantly blocked mechanical allodynia produced by compression of the trigeminal ganglion. These findings suggest that prolonged nociceptive behavior following compression of the trigeminal ganglion may mimic trigeminal neuralgia in this animal model.
A pilot study of clonazepam versus psychodynamic group therapy plus clonazepam in the treatment of generalized social anxiety disorder
Authors: Knijnik Daniela Z. , Blanco Carlos , Salum Giovanni Abrahão , Moraes Carolina U. , Mombach Clarissa , Almeida Ellen , Pereira Marília , Strapasson Atahualpa , Manfro Gisele G. , Eizirik Cláudio L.
Published: September 2008

Background

Both psychodynamic group therapy (PGT) and clonazepam are used as treatment strategies in reducing symptoms of generalized social anxiety disorder (GSAD). However, many individuals remain symptomatic after treatment with PGT or clonazepam.

Method

Fifty-eight adult outpatients with a diagnosis of GSAD according to DSM-IV were randomized to 12 weeks PGT plus clonazepam or clonazepam. The Clinical Global Impression-Improvement (CGI-I) Scale was the primary efficacy measure. Secondary efficacy measures included the Liebowitz Social Anxiety Scale (LSAS) total score, the World Health Organization Instrument to Assess Quality of Life—Brief (WHOQOL-Bref) Scale and the Beck Depression Inventory (BDI).

Results

CGI-I data from 57 patients (intent-to-treat population) showed that patients who received PGT plus clonazepam presented significantly greater improvement than those who received clonazepam (P = 0.033). There were no significant differences between the two groups in the secondary efficacy measures.

Conclusions

Our study suggests that the combination of PGT with clonazepam may be a promising strategy for the treatment of GSAD, regarding gains in the global functioning. However the present study failed to detect more specific changes in social anxiety symptomatology between the two groups.
Facial emotion recognition and its relationship to symptomatic, subjective, and functional outcomes in outpatients with chronic schizophrenia
Authors: Hofer Alex , Benecke Cord , Edlinger Monika , Huber Regina , Kemmler Georg , Rettenbacher Maria A. , Schleich Gerald , Wolfgang Fleischhacker W.
Published: September 2008

Outcome in schizophrenia is multidimensional and consists of clinical and psychosocial domains. Difficulties in affect recognition are a hallmark of schizophrenia, but there is little research investigating the consequences of this deficit on patients’ psychosocial status. This cross-sectional study examined the relationship of facial affect recognition and treatment outcomes in terms of psychopathology, quality of life (QOL), and psychosocial functioning.

We investigated 40 regular attendees of a specialized schizophrenia outpatient clinic who had been stable both from a symptomatic and a medication perspective for a minimum of 6 months and 40 healthy volunteers who were chosen to match patients in age, sex, and education. Affect recognition was positively associated with patients’ level of education and negatively with increasing age. Deficits in this area corresponded to the severity of negative and affective symptoms as well as to poor work and global functioning. These findings suggest that affect recognition is an important aspect of psychosocial functioning in stable outpatients with schizophrenia.
Development and evaluation of a case group concept for inpatients with mental disorders in Germany: Using self-report and expert-rated instruments
Authors: Andreas Sylke , Dirmaier Jörg , Harfst Timo , Kawski Stephan , Koch Uwe , Schulz Holger
Published: September 2008

The aim of this study was to evaluate a case-mix system to classify inpatients with mental disorders in Germany by means of self-report and expert-rated instruments. The use of case-mix systems enhances the transparency of performance and cost structure and can thus improve the quality of mental health care. We analysed a consecutive sample of 1677 inpatients with mental disorders from 11 hospitals using regression tree analysis. The model assigns patients to 17 groups, accounting for 17% of the variance for duration of stay. Patients with eating disorders had a longer duration of stay than patients with anxiety disorder, duration of mental illness of less than 3–5 years, lower levels of interpersonal problems and higher occupational position. The results showed that besides diagnosis, variables such as duration of illness and interpersonal problems are important for classifying inpatients with mental disorders. The results of the study should be critically reviewed regarding the empirical results of other studies and the appropriateness of case group concepts for inpatients with mental disorders.
Childhood trauma as a correlative factor of suicidal behavior – via aggression traits. Similar results in an Italian and in a French sample
Authors: Sarchiapone M. , Jaussent I. , Roy A. , Carli V. , Guillaume S. , Jollant F. , Malafosse A. , Courtet P.
Published: September 2008

Background and objective

Childhood trauma and aggressive traits are considered risk factors for suicidal behavior. The hypothesis we aimed to test in this study was the existence of an association between childhood trauma and aggression in two distinct samples of Italian and French suicide attempters.

Method

Study participants comprise 587 subjects with different psychiatric diagnoses according to DSM-IV-TR criteria. Three different samples were analyzed and compared: a group of French suicide attempters (N = 396; mean age 40.47 SD = 13.52; M/F: 110/286); a group of Italian suicide attempters (N = 103; mean age 38.60 SD = 12.04; M/F 27/76) and an Italian psychiatric comparison group (N = 88; mean age: 41.49 SD = 12.05; M/F; 37/51). Patients were interviewed with the Brown–Goodwin Assessment for Lifetime History of Aggression (BGLHA) and the Childhood Trauma Questionnaire (CTQ) 34-items for Italian data and 28-items for French data.

Results

When compared with the comparison group, Italian suicide attempters had significantly higher scores on the BGLHA scale and reported higher scores on the CTQ scores for physical abuse, sexual abuse and emotional abuse. Significant correlations between childhood trauma and aggression were found in both groups, Italian and French, of suicide attempters.

Conclusion

The hypothesis tested was supported as psychiatric patients who had attempted suicide reported significantly more childhood trauma and aggression. Significant correlations were found between aggressive behavior, and childhood trauma in suicidal patients. This finding was replicated in two independently recruited samples in two countries with different prevalence of suicidal behavior.
δ‐Opioid receptors stimulate ERK1/2 activity in NG108‐15 hybrid cells by integrin‐mediated transactivation of TrkA receptors
Authors: Eisinger Daniela A. , Ammer Hermann
Published: September 2008

This study demonstrates that activation of δ‐opioid receptors (DORs) in neuroblastoma × glioma (NG108‐15) hybrid cells by [d‐Ala2,d‐Leu5]enkephalin (DADLE) and etorphine significantly enhances cell adhesion to fibronectin‐coated wells. This effect is blocked by both naloxone and integrin binding RGDT peptides. In addition, cell adhesion turned out to be a prerequisite for DOR‐stimulated transactivation of Tropomyosin‐related kinase A (TrkA) and extracellular signal‐regulated kinases 1/2 (ERK1/2). Because inhibition of TrkA activation by AG879 completely blocked DOR‐ and integrin‐mediated ERK1/2 signaling, the present results indicate that in NG108‐15 cells DOR‐stimulated ERK1/2 activation is mediated by integrin‐induced transactivation of TrkA.
Simulations of a G protein‐coupled receptor homology model predict dynamic features and a ligand binding site
Authors: Wolf Steffen , Böckmann Marcus , Höweler Udo , Schlitter Jürgen , Gerwert Klaus
Published: September 2008

A computational approach to predict structures of rhodopsin‐like G protein‐coupled receptors (GPCRs) is presented and evaluated by comparison to the X‐ray structural models. By combining sequence alignment, the rhodopsin crystal structure, and point mutation data on the β2 adrenoreceptor (b2ar), we predict a (−)‐epinephrine‐bound computational model of the β2 adrenoreceptor. The model is evaluated by molecular dynamics simulations and by comparison with the recent X‐ray structures of b2ar. The overall correspondence between the predicted and the X‐ray structural model is high. Especially the prediction of the ligand binding site is accurate. This shows that the proposed dynamic homology modelling approach can be used to create reasonable models for the understanding of structure and dynamics of other rhodopsin‐like GPCRs.
Characterization of mammalian sedoheptulokinase and mechanism of formation of erythritol in sedoheptulokinase deficiency
Authors: Kardon Tamas , Stroobant Vincent , Veiga-da-Cunha Maria , Schaftingen Emile Van
Published: September 2008

Our aim was to identify the product formed by sedoheptulokinase and to understand the mechanism of formation of erythritol in patients with sedoheptulokinase deficiency. Mouse recombinant sedoheptulokinase was found to be virtually specific for sedoheptulose and its reaction product was identified as sedoheptulose 7‐phosphate. Assays of sedoheptulose in plant extracts disclosed that this sugar is present in carrots (≈7 μmol/g) and in several fruits. Sedoheptulose 1‐phosphate is shown to be a substrate for aldolase B, which cleaves it to dihydroxyacetone‐phosphate and erythrose. This suggests that, in patients deficient in sedoheptulose‐7‐kinase, sedoheptulose is phosphorylated by fructokinase to sedoheptulose 1‐phosphate. Cleavage of the latter by aldolase B would lead to the formation of erythrose, which would then be reduced to erythritol.
Structural and functional studies of Streptococcus pneumoniae neuraminidase B: An intramolecular trans‐sialidase
Authors: Gut Heinz , King Samantha J. , Walsh Martin A.
Published: September 2008

The human pathogen Streptococcus pneumoniae expresses neuraminidase proteins that cleave sialic acids from complex carbohydrates. The pneumococcus genome encodes up to three neuraminidase proteins that have been shown to be important virulence factors. Here, we report the first structure of a neuraminidase from S. pneumoniae: the crystal structure of NanB in complex with its reaction product 2,7‐anhydro‐Neu5Ac. Our structural data, together with biochemical analysis, establish NanB as an intramolecular trans‐sialidase with strict specificity towards α2‐3 linked sialic acid substrates. In addition, we show that NanB differs in its substrate specificity from the other pneumococcal neuraminidase NanA.
Misacylation of pyrrolysine tRNA in vitro and in vivo
Authors: Gundllapalli Sarath , Ambrogelly Alexandre , Umehara Takuya , Li Darrick , Polycarpo Carla , Söll Dieter
Published: September 2008

Methanosarcina barkeri inserts pyrrolysine (Pyl) at an in‐frame UAG codon in its monomethylamine methyltransferase gene. Pyrrolysyl‐tRNA synthetase acylates Pyl onto tRNAPyl, the amber suppressor pyrrolysine Pyl tRNA. Here we show that M. barkeri Fusaro tRNAPyl can be misacylated with serine by the M. barkeri bacterial‐type seryl‐tRNA synthetase in vitro and in vivo in Escherichia coli. Compared to the M. barkeri Fusaro tRNA, the M. barkeri MS tRNAPyl contains two base changes; a G3:U70 pair, the known identity element for E. coli alanyl‐tRNA synthetase (AlaRS). While M. barkeri MS tRNAPyl cannot be alanylated by E. coli AlaRS, mutation of the MS tRNAPyl A4:U69 pair into C4:G69 allows aminoacylation by E. coli AlaRS both in vitro and in vivo.
Pyruvate uptake is inhibited by valproic acid and metabolites in mitochondrial membranes
Authors: Aires Cátia C.P. , Soveral Graça , Luís Paula B.M. , ten Brink Herman J. , de Almeida Isabel Tavares , Duran Marinus , Wanders Ronald J.A. , Silva Margarida F.B.
Published: September 2008

The pyruvate uptake rate in inverted submitochondrial vesicles prepared from rat liver was optimized and further characterized; the potential inhibitory effects of the anticonvulsive drug valproic acid or 2‐n‐propyl‐pentanoic acid (VPA), Δ4‐valproic acid or 2‐n‐propyl‐4‐pentenoic acid and the respective coenzyme A (CoA) conjugates were studied in the presence of a proton gradient. All tested VPA metabolites inhibited the pyruvate uptake, but the CoA esters were stronger inhibitors (40% and 60% inhibition, respectively, for valproyl‐CoA and Δ4‐valproyl‐CoA, at 1 mM). At the same concentration, the specific inhibitor 2‐cyano‐4‐hydroxycinnamate decreased the pyruvate uptake rate by 70%. The reported inhibition of the mitochondrial pyruvate uptake may explain the significant impairment of the pyruvate‐driven oxidative phosphorylation induced by VPA.
In vivo requirement of TGF‐β/GDNF cooperativity in mouse development: focus on the neurotrophic hypothesis
Authors: Rahhal Belal , Heermann Stephan , Ferdinand Anika , Rosenbusch Joachim , Rickmann Michael , Krieglstein Kerstin
Published: September 2008

Neurotrophic factors are well‐recognized extracellular signaling molecules that regulate neuron development including neurite growth, survival and maturation of neuronal phenotypes in the central and peripheral nervous system. Previous studies have suggested that TGF‐β plays a key role in the regulation of neuron survival and death and potentiates the neurotrophic activity of several neurotrophic factors, most strikingly of GDNF. To test the physiological relevance of this finding, TGF‐β2/GDNF double mutant (d‐ko) mice were generated. Double mutant mice die at birth like single mutants due to kidney agenesis (GDNF−/−) and congential cyanosis (TGF‐β2−/−), respectively. To test for the in vivo relevance of TGF‐β2/GDNF cooperativity to regulate neuron survival, mesencephalic dopaminergic neurons, lumbar motoneurons, as well as neurons of the lumbar dorsal root ganglion and the superior cervical ganglion were investigated. No loss of mesencephalic dopaminergic neurons was observed in double mutant mice at E18.5. A partial reduction in neuron numbers was observed in lumbar motoneurons, sensory and sympathetic neurons in GDNF single mutants, which was further reduced in TGF‐β2/GDNF double mutant mice at E18.5. However, TGF‐β2 single mutant mice showed no loss of neurons. These data point towards a cooperative role of TGF‐β2 and GDNF with regard to promotion of survival within the peripheral motor and sensory systems investigated.
The CALM and CALM/AF10 interactor CATS is a marker for proliferation
Authors: Archangelo Leticia Fröhlich , Greif Philipp A. , Hölzel Michael , Harasim Thomas , Kremmer Elisabeth , Przemeck Gerhard K.H. , Eick Dirk , Deshpande Aniruddha Jayant , Buske Christian , Hrabé de Angelis Martin , Olalla Saad Sara Teresinha , Bohlander Stefan K.
Published: September 2008

The CATS protein was recently identified as a novel CALM interacting protein. CATS increases the nuclear and specifically the nucleolar localization of the leukemogenic CALM/AF10 fusion protein. We cloned and characterized the murine Cats gene. Detailed analysis of murine Cats expression during mouse embryogenesis showed an association with rapidly proliferating tissues. Interestingly, the Cats transcript is highly expressed in murine hematopoietic cells transformed by CALM/AF10. The CATS protein is highly expressed in leukemia, lymphoma and tumor cell lines but not in non‐proliferating T‐cells or human peripheral blood lymphocytes. CATS protein levels are cell cycle dependent and it is induced by mitogens, suggesting a role of CATS in the control of cell proliferation and possibly CALM/AF10‐mediated leukemogenesis.
Fluctuating abundance of humpback whales (Megaptera novaeangliae) in a calving ground off coastal Brazil
Authors: Morete Maria E. , Bisi Tatiana L. , Pace Richard M. , Rosso Sergio
Published: September 2008

The humpback whale (Megaptera novaeangliae) population that uses Abrolhos Bank, off the east coast of Brazil as a breeding ground is increasing. To describe temporal changes in the relative abundance of humpback whales around Abrolhos, seven years (1998–2004) of whale count data were collected during July through to November. During one-hour-scans, observers determined group size within 9.3 km (5 n.m.) of a land-based observing station. A total of 930 scans, comprising 7996 sightings of adults and 2044 calves were analysed using generalized linear models that included variables for time of day, day of the season, years and two-way interactions as possible predictors. The pattern observed was the gradual build-up and decline in whale counts within seasons. Patterns and peaks of adult and calf counts varied among years. Although fluctuation was observed, there was generally an increasing trend in adult counts among years. Calf counts increased only in 2004. These fluctuations may have been caused by some environmental conditions in humpback whales' summering grounds and also by changes in spatial–temporal concentrations in Abrolhos Bank. The general pattern observed within the study area mirrored what was observed in the whole Abrolhos Bank. Knowledge of the consistency with which humpback whales use this important nursing area should prove beneficial for designing future monitoring programmes especially related to whale watching activities around Abrolhos Archipelago.
Individual identification and habitat use of the estuarine dolphin Sotalia guianensis (Cetacea: Delphinidae) in Cananéia, south-eastern Brazil, using video images
Authors: de Oliveira L.V. , Monteiro-Filho E.L.A.
Published: September 2008

Individual identification using Hi8 video images was tested on the population of estuarine dolphins, Sotalia guianensis that inhabit the Cananéia estuary, south-eastern Brazil. Between June 2001 and August 2002, 25 different dolphins were identified by nicks on the dorsal fin (80%) and by the association of cuts and scratches on the dorsal fin and the body's dorsal region (20%). The existent marks were used to create an identification key to ease the matching between dolphins. The animals were present on 100% of the sampled days, and some of them were repeatedly registered at the same sector in the area, suggesting that although they occupy an extensive area, they use it in an intended way. When compared to researches that used photographs to identify cetaceans, the video images showed some loss of information, nevertheless the analysis could be done without impairment of results, therefore this method proved to be efficient.
Harbour porpoise (Phocoena phocoena) static acoustic monitoring: laboratory detection thresholds of T-PODs are reflected in field sensitivity
Authors: Kyhn Line A. , Tougaard Jakob , Teilmann Jonas , Wahlberg Magnus , Jørgensen Poul B. , Bech Nikolaj I.
Published: September 2008

The T-POD (Timing POrpoise Detector) is a self-contained acoustic data logger used for detecting and monitoring the presence of echolocation clicks of small cetaceans. It has become a standard tool in environmental impact assessments and monitoring programmes. Yet, little is known about the variability in sensitivity and detection range of T-PODs. In this study the field performance of ten v3 T-PODs was compared to detection thresholds measured in a tank. The T-POD thresholds ranged from 123 to 132 dB re 1μPa (pp). The detection thresholds of the ten individual T-PODs were different and the differences increased over time. The more sensitive a T-POD was in the laboratory (i.e. the lower the threshold) the more clicks were recorded by it in the field. Threshold correlated differently to the five analysed T-POD parameters (encounters, encounter duration, waiting time, porpoise positive minutes, clicks per porpoise positive minute). This study demonstrates that individual threshold calibrations of T-PODs are necessary to obtain comparable results when monitoring odontocetes with this tool. Regression equations for relationships between T-POD detection thresholds and study parameters obtained during field trials may allow comparisons of T-PODs with different detection thresholds.
The size and complexity of dolphin brains—a paradox?
Authors: Huggenberger Stefan
Published: September 2008

Dolphin brain size with respect to body size ranks between that of apes and humans. The hypertrophic auditory structures, the large cerebrum with extended gyrification and the highly cognitive capabilities of toothed whales seem to be in paradoxical contrast to their thin neocortex with a plesiomorphic or paedomorphic cytoarchitecture. The total number of neurons in the delphinid neocortex is comparable to that of the chimpanzee (Primates), but, in relation to body weight, in the magnitude of the hedgehog (Insectivora) neocortex since cetaceans may be able to obtain larger body sizes than terrestrial mammals due to reduced gravitational effects in water. During evolution, dolphins may have increased the computational performance of their cytoarchitectonically ‘simple’ neocortex by a multiplication of relevant structures (resulting in a hypertrophic surface area) instead of increasing its complexity. Based on this hypothesis, I suggest that the evolution of the large dolphin brain was possible due to a combination of different prerequisites based on adaptations to the aquatic environment including the sonar system. The latter facilitated a successful feeding strategy to support an increased metabolic turnover of the brain and led to a hypertrophic auditory system. Moreover, the rudimentary pelvic girdle did not limit brain size at birth. These adaptations favoured the evolutionary size increase of the cerebral cortex in dolphins facilitating highly cognitive capabilities as well as precise and rapid sound processing using a ‘simple’ kind of neocortical cytoarchitecture.
Relative abundance, density and distribution of the harbour porpoise (Phocoena phocoena) along the west coast of the UK
Authors: Goodwin L. , Speedie C.
Published: September 2008

The harbour porpoise(Phocoena phocoena)is the most frequently sighted cetacean in the UK, yet there is a conservation need to assess both abundance and distribution for this species. During May–August, 2002–2004 a boat-based visual survey, employing effort-related line transect methodology was conducted for specified areas of the west coast of the UK. Estimates of relative abundance were made, with full DISTANCE analysis being carried out during 2004 for each of the areas surveyed. A generalized additive model (GAM) was constructed examining porpoise presence in relation to month, position (latitude and longitude), depth and sea surface temperature for all years and for each year of the study individually. Harbour porpoise density showed a significant decrease in the South West, with an increase for West Scotland over the study period, whilst the highest numbers for both Northern Ireland and the Firth of Clyde were recorded in 2003. The porpoise population in the south-west of England was estimated at 163 (67LCI–400UCI) individuals during the months of May and June, 387 (170LCI–877UCI) individuals were present off Northern Ireland during July, 1645 (823LCI–3289UCI) individuals around the Firth of Clyde in July and 3105 (2032LCI–4745UCI) off West Scotland during August and September. The GAM demonstrated that porpoise presence increased around the 100 m depth contour. Whilst further research is required in each of the areas throughout the year, this study provides important information on the distribution and habitat use of the harbour porpoise within UK waters.
Colour patterns and pigmentation variability on striped dolphin Stenella coeruleoalba in north-western Mediterranean Sea
Authors: Rosso Massimiliano , Moulins Aurélie , Würtz Maurizio
Published: September 2008

Studies on differences in external morphology and pigmentation patterns were historically carried out using stranded individuals or opportunistic sightings; few studies have involved sampling systematically free-ranging individuals. In order to investigate and describe main pigmentation characteristics, outlining ‘typical’ regional pigmentations, this work analysed systematic photographic information taken on free-ranging striped dolphins, Stenella coeruleoalba. Photographs of dolphins in the Ligurian Sea were collected between May 2004 and December 2006. All individuals were described by the presence/absence of pigmentation variables and by differences in colour shades. The frequency of all the pigmentation variables analysed is stable in the population (10 ‘gene’ variables, 19 ‘allele’ variables), and remains similar between each different group of dolphins. But population presents widespread pigmentation variability between specimens, allowing identification even at single individual level. Cluster analysis also found that the majority of the pigmentations derive from two main colour patterns, called ‘mat’ and ‘pale’ patterns (fmat = 0.68; fpale = 0.12). The Bray–Curtis index showed a high variability of the intra-group pigmentation distance between groups. This resulted in a positive correlation between group size and ‘intra-group’ pigmentation distance: the distance increases rapidly up to a group size of 40 individuals. According to the results obtained, the striped dolphins seem to be concentrated in small groups in which there is a large phenotypic similarity among individuals. These small units could be associated between them to form temporary large groups observed only in pelagic waters.
Angular distributions of albedo protons at the near earth orbit
Authors: Wang Kaiti , Huang Ming‐Huey A.
Published: September 2008

A new insight into angular distributions of albedo proton fluxes is assessed by modeling the size of loss cone at 380‐km altitude. The percentage occupied by particle populations of each categorized flight time at a spatial point can then be related to the local angular distribution of their fluxes; accordingly, the global percentage of each population thus can be obtained. The global percentages of the albedo protons that were derived from the Alpha Magnetic Spectrometer (AMS) data are chosen as the benchmarks. Angular distributions of particle fluxes were found to conform these benchmarks under the following three cases: (1) a very anisotropic pitch angle distribution when both the bounce‐loss and drift‐loss populations are assumed to be generated at the local atmosphere; (2) a zenith‐angle distribution with an isotropic component exceeding the anisotropic component and include the drift‐loss population originated from other locations; (3) a pure isotropic distribution with a drift‐loss population originated from other locations included to account for the detected fluxes. Case 3 is most likely to represent what have really occurred since it could reproduce the observed results of AMS well. Our study has focused on the theoretical relation between angular distributions and percentages of various flight time populations. The consistency with observations suggests that it is worthwhile to feature future new instruments to measure the angular distributions of the albedo proton and to carry out further theoretical calculations to explore the energy input to the environment by the albedo particles.
Seismic constraints on a large mafic intrusion with implications for the subsidence history of the Danish Basin
Authors: Sandrin Alessandro , Thybo Hans
Published: September 2008

Seismic refraction data from the ESTRID‐1 profile are used for seismic velocity modeling along the strike of a large mafic intrusion in the Norwegian‐Danish Basin, central Denmark. The P wave velocity structure identifies a ∼8 km thick sedimentary succession with velocities between 1.8 and 5.7 km/s. The top basement is defined by a step to vp = 6.2 km/s. In the middle to lower crust a high‐velocity body (vp > 6.7 km/s), with its top located at about 10–12 km depth, is interpreted as a high‐velocity and high‐density gabbroic intrusion of Permian age. This high‐velocity body explains the large (∼50 mGal) positive gravity anomaly known as Silkeborg Gravity High. The intrusion has a minimum volume of 40,000 km3, which implies that the magma influx and the consequent cooling of the lithosphere from high temperature could have had profound effects on the subsidence of the Danish Basin, in particular because the magma probably intruded during only a few events and other similar structures cover much of the basin. An anomalously high velocity gradient (from 7.0 km/s in the middle crust to 7.7 km/s at 30–32 km depth) in the central part of the intrusion coincides with an interval without Moho reflections, indicative of a gradual transition zone between the crust and the mantle. This feature may show the location of the feeder dykes of the intrusion.
Variation of H2O/CO2 and CO2/SO2 ratios of volcanic gases discharged by continuous degassing of Mount Etna volcano, Italy
Authors: Shinohara H. , Aiuppa A. , Giudice G. , Gurrieri S. , Liuzzo M.
Published: September 2008

We applied the Multi‐GAS technique to measure compositions of the volcanic plumes continuously discharged from summit craters of Voragine, Northeast and Bocca Nuova at Mount Etna, in an attempt to estimate compositions of the source volcanic gases. The estimated CO2/SO2 and H2O/CO2 ratios of the volcanic gases show a large variation ranging from 0.6 to 30 and from 1 to 18, respectively. This variability overlaps with the compositional range of dissolved volatiles in melt inclusions and their coexisting bubbles in a magma chamber and can be caused by the low‐pressure degassing of a magma with variable bubble content ranging from 0.3 to 15 wt.%. The variable bubble content in the magma is likely a result of supply of deep‐derived CO2‐rich gas phase to the chamber and subsequent bubble‐magma differentiation by bubble ascent in the magma chamber. In contrast, the variation of volcanic gas composition can also be caused by changes of degassing pressure (gas–magma separation pressure), ranging from 0 to 100 MPa, as a result of changes in the depth of the top of the convecting magma in volcanic conduits. Both mechanisms can cause similar compositional variations. However, the two mechanisms will result in contrasting correlations between the SO2 emission rates and the gas compositions that can be examined by parallel observations of the emission rates and compositions in the future.