bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon loss induced by plasma beam irradiation in porous silica films
Authors: Kurihara K. , Ono T. , Kohmura K. , Tanaka H. , Fujii N. , Hata N. , Kikkawa T.
Published: June 2007

Plasma-induced damages of porous silica films during plasma processes were investigated by using a plasma beam irradiation apparatus. We used the porous silica films incorporated with methyl groups to achieve high hydrophobicity. The carbon (methyl group) reductions in the film as an index of the level of damages induced by Ar, He, O2, H2, and N2 plasma irradiations were examined by x-ray photoelectron spectroscopy and secondary ion mass spectroscopy. The damage due to Ar and He plasma bombardment increased with an increase in the ion dosage, although it was not strongly affected by the ion energy in the range higher than 130eV. Furthermore, it was found that the damage near the film surface was influenced more by metastable He atoms than by metastable Ar atoms. Both O ions and O atoms caused severe damage. N atoms did not affect the decrease of carbon content but reacted with carbon to form CN bonds. H atoms decreased carbon content slightly, but the amount of decrease was saturated by the further irradiation of H atoms.
Sharp assembly of small clusters obtained by atom deposition for room temperature Coulomb blockade
Authors: Lidgi-Guigui N. , Seneor P. , Nguyen Van Dau F. , Friederich A. , Vaurès A. , Deranlot C.
Published: June 2007

The growth of a nanocluster assembly on a processed AlOx and its electronic transport behavior are investigated. An Ar+ plasma was used in order to create defects of high trapping energy on an AlOx layer. This process promotes a shift of the cluster distribution towards smaller sizes and allows to sharpen it. In a second part, the authors show that the application of this techniqueto clusters inserted in a tunnel junction can lead to a dramatic increase in the temperature range over which Coulomb blockade can be observed.
Dynamic photolytical actinometry of the vacuum-ultraviolet radiation produced by multichannel surface discharges of submicrosecond duration
Authors: Tcheremiskine V. I. , Uteza O. P. , Sentis M. L. , Mikheev L. D.
Published: June 2007

Absolute measurements of the vacuum-ultraviolet (VUV) radiation power produced by a planar broadband optical source of submicrosecond light pulse duration are carried out in the transient regime of formation of a photodissociation (bleaching) wave in a photodecomposing absorptive medium. The source is based on a multichannel surface discharge initiated in Ar∕N2 gas mixtures on the area of ∼0.1m2. The energetic characteristics of the produced VUV radiation are determined on the basis of spatially and temporally resolved observations of the pulsed photolysis of XeF2 vapors. It is shown that the photon flux intensity produced by the source within the spectral range of 120–200nm reaches 1.1×1023photons∕cm2s corresponding to the effective brightness temperature of discharge plasma of 20kK and to the intrinsic efficiency of the discharge VUV emission of 3.2%. Numerical simulations of the photolysis process show a rather weak sensitivity of the results to the fraction of discharge radiation emitted into the line spectrum, as well as to the angular distribution of emitted radiation. The spectral band of measurements can be selected according to the choice of parent photodecomposing particles.
Leakage currents at crystallites in ZrAlxOy thin films measured by conductive atomic-force microscopy
Authors: Bierwagen O. , Geelhaar L. , Gay X. , Piešiņš M. , Riechert H. , Jobst B. , Rucki A.
Published: June 2007

The spatial distribution of the leakage current through ZrAlxOy thin films with different degrees of crystallinity was investigated at the nanometer-scale. Conductive atomic-force microscopy shows leakage currents at low electric fields in the polycrystalline but not in the amorphous films. Leakage occurs at large crystallites that protrude from the surface. Ring-shaped current distributions around some of the crystallites suggest a conduction at the boundary of crystalline grain and amorphous matrix, and not through the grain. In contrast, the leakage spots that are observed in amorphous films at high electric fields are not correlated to the morphology.
High-density capacitors based on amorphous BaTiO3 layers grown under hydrogen containing atmosphere
Authors: Gonon P. , El Kamel F.
Published: June 2007

Addition of hydrogen (H2) during the sputter deposition of BaTiO3 amorphous thin films drastically modifies their dielectric properties. Films grown under hydrogen containing atmospheres display large capacitances (several μF∕cm2 for 1μm thick films), that are hundred times higher than capacitances measured for films grown without hydrogen. This is explained by the formation of a double-layer capacitor which arises from mobile protons (protonic conduction with an activation energy around 0.3eV). These films could find applications for the elaboration of integrated supercapacitors.
Formation and photopatterning of nanoporous titania thin films
Authors: Park Oun-Ho , Cheng Joy Y. , Kim Hyun Suk , Rice Philip M. , Topuria Teya , Miller Robert D. , Kim Ho-Cheol
Published: June 2007

Photopatternable nanoporous titania thin films were generated from mixtures of an organic diblock copolymer, poly(styrene-b-ethylene oxide) (PS-b-PEO), and an oligomeric titanate (OT) prepared from a chelated titanium isopropoxide. The PS-b-PEO templates well-defined microdomains in thin films of the mixtures, which upon thermal treatment at 450°C, become nanopores in titania. Average pore size and porosity are controlled by the molecular weight and loading level of the PS-b-PEO, respectively. Patterns of nanoporous titania were created by selectively exposing UV light on the mixture films. The UV irradiation destroys the chelating bond and induces the cross-linking reaction of the OT. Subsequent wet development followed by thermal treatment gives patterned nanoporous films of anatase phase titania.
Room temperature deposited indium zinc oxide thin film transistors
Authors: Wang Yu-Lin , Ren F. , Lim Wantae , Norton D. P. , Pearton S. J. , Kravchenko I. I. , Zavada J. M.
Published: June 2007

Depletion-mode indium zinc oxide (IZO) channel thin film transistors were fabricated on glass substrates from layers deposited at room temperature using rf magnetron sputtering. The threshold voltage was in the range from −5.5to−6.5V depending on gate dielectric (SiO2) thickness and the drain current on-to-off ratio was ∼105. The maximum field effect mobility in the channel was ∼4.5cm2V−1s−1, lower than the Hall mobility of ∼17cm2V−1s−1 in the same layers, suggesting a strong influence of scattering due to trapped charges at the SiO2-IZO interface. The low deposition and processing temperatures make these devices suitable for applications requiring flexible substrates.
Control of magnesium oxide nanowire morphologies by ambient temperature
Authors: Nagashima Kazuki , Yanagida Takeshi , Tanaka Hidekazu , Kawai Tomoji
Published: June 2007

Although controlling morphologies of oxide nanowires formed using vapor-liquid-solid (VLS) mechanism is desired in developing functional oxide-nanowire applications, a comprehensive understanding of the key factors affecting oxide-nanowire VLS growth is still lacking. Here, the authors demonstrate the controllability of magnesium oxide nanowire morphologies by varying the ambient temperature and discuss the underlying mechanism. Decreasing the ambient temperature resulted in shorter, tapered, and square-rod shaped nanowires, whereas increasing the ambient temperature allowed fabricating longer and untapered nanowires. The variation of oxide-nanowire morphologies is interpreted in terms of the competition between the VLS growth and the sidewall growth due to the variation of adatom transport.
Double hysteresis loop in Cu-doped K0.5Na0.5NbO3 lead-free piezoelectric ceramics
Authors: Lin Dunmin , Kwok K. W. , Chan H. L. W.
Published: June 2007

In this letter the authors report the observation of double hysteresis loops in Cu-doped K0.5Na0.5NbO3 (KNN) ceramics. Unlike other ferroelectric titanates (e.g., BaTiO3), aging is not required for the ceramic to exhibit the double-loop-like characteristics. Based on the symmetry-conforming principle of point defects, it is suggested that defect dipoles are formed by the acceptor dopant ions-Cu2+ and O2− vacancies along the polarization direction after the diffuse tetragonal-orthorhombic phase transition of the ceramic. Because of the low migration rates of defects, the defect dipoles remain in the original orientation during the P-E loop measurement, providing a restoring force to reverse the switched polarization. The defect dipoles also provide “pinning” effects in the normal piezoelectric activities. As a result, the ceramic becomes “hardened,” exhibiting an extraordinarily high mechanical quality factor (2500), while the other piezoelectric properties remain reasonably good: electromechanical coupling coefficients kp=39%, kt=47%, and piezoelectric coefficient d33=82pC∕N.
In situ study of the growth of ZnO nanosheets using environmental scanning electron microscope
Authors: Zhang Jingmin , Zhang Xinzheng , Chen Li , Xu Jun , You Liping , Ye Hengqiang , Yu Dapeng
Published: June 2007

The authors demonstrated an investigation of the real-time growth of ZnO nanosheets via in situ observation in an environmental scanning electron microscope. It was found that ZnO nanosheets were grown in a two-stage process: [21¯1¯0]-oriented nanowires were grown first, and then ZnO nanosheets grew perpendicularly on the parent nanowires along the [0001] axis. The authors’ results revealed that the change of the ZnO growth direction from [21¯1¯0] (a axis) to [0001] (c axis) can be achieved by control of the growth temperature.
Influence of base stacking on excited-state behavior of polyadenine in water, based on time-dependent density functional calculations
Authors: Santoro F. , Barone V. , Improta R.
Published: June 2007

A thorough study of the excited-state properties of the stacked dimers and trimers of 9-methyladenine in B-DNA conformation has been performed in aqueous solution by using time-dependent density functional calculations and the solvent polarizable continuum model, and results were compared with experimental results on polyadenine oligomers. The effect of base stacking on the absorption and emission spectra is fully reproduced by our calculations. Although light absorption leads to a state (S
B
) delocalized over several nucleobases, excited-state geometry optimization indicates that S
B
subsequently evolves into a state in which the excitation is localized on a single base. Analysis of the excited-state potential energy surfaces shows that S
B
can easily decay into the lowest energy excited state, S
CT
, which is a dark excimer produced by intermonomer charge transfer between two stacked bases. The subpicosecond features of the time-resolved experiments are interpreted in terms of ultrafast decay from S
B
. After localization, two easy, radiationless decay channels are indeed open for S
B
: (
i
) ground-state recovery, according to the same mechanisms proposed for isolated adenine and/or (
ii
) decay to S
CT
. Our calculations suggest that the slowest part of the excited-state dynamics detected experimentally involves the S
CT
state.
Reciprocal inhibition between Pax7 and muscle regulatory factors modulates myogenic cell fate determination
Authors: Olguin Hugo C. , Yang Zhihong , Tapscott Stephen J. , Olwin Bradley B.
Published: June 2007

Postnatal growth and regeneration of skeletal muscle requires a population of resident myogenic precursors named satellite cells. The transcription factor Pax7 is critical for satellite cell biogenesis and survival and has been also implicated in satellite cell self-renewal; however, the underlying molecular mechanisms remain unclear. Previously, we showed that Pax7 overexpression in adult primary myoblasts down-regulates MyoD and prevents myogenin induction, inhibiting myogenesis. We show that Pax7 prevents muscle differentiation independently of its transcriptional activity, affecting MyoD function. Conversely, myogenin directly affects Pax7 expression and may be critical for Pax7 down-regulation in differentiating cells. Our results provide evidence for a cross-inhibitory interaction between Pax7 and members of the muscle regulatory factor family. This could represent an additional mechanism for the control of satellite cell fate decisions resulting in proliferation, differentiation, and self-renewal, necessary for skeletal muscle maintenance and repair.
Nodes of Ranvier and axon initial segments are ankyrin G–dependent domains that assemble by distinct mechanisms
Authors: Dzhashiashvili Yulia , Zhang Yanqing , Galinska Jolanta , Lam Isabel , Grumet Martin , Salzer James L.
Published: June 2007

Axon initial segments (AISs) and nodes of Ranvier are sites of action potential generation and propagation, respectively. Both domains are enriched in sodium channels complexed with adhesion molecules (neurofascin [NF] 186 and NrCAM) and cytoskeletal proteins (ankyrin G and βIV spectrin). We show that the AIS and peripheral nervous system (PNS) nodes both require ankyrin G but assemble by distinct mechanisms. The AIS is intrinsically specified; it forms independent of NF186, which is targeted to this site via intracellular interactions that require ankyrin G. In contrast, NF186 is targeted to the node, and independently cleared from the internode, by interactions of its ectodomain with myelinating Schwann cells. NF186 is critical for and initiates PNS node assembly by recruiting ankyrin G, which is required for the localization of sodium channels and the entire nodal complex. Thus, initial segments assemble from the inside out driven by the intrinsic accumulation of ankyrin G, whereas PNS nodes assemble from the outside in, specified by Schwann cells, which direct the NF186-dependent recruitment of ankyrin G.
uPAR-induced cell adhesion and migration: vitronectin provides the key
Authors: Madsen Chris D. , Ferraris Gian Maria Sarra , Andolfo Annapaola , Cunningham Orla , Sidenius Nicolai
Published: June 2007

Expression of the membrane receptor uPAR induces profound changes in cell morphology and migration, and its expression correlates with the malignant phenotype of cancers. To identify the molecular interactions essential for uPAR function in these processes, we carried out a complete functional alanine scan of uPAR in HEK293 cells. Of the 255 mutant receptors characterized, 34 failed to induce changes in cell morphology. Remarkably, the molecular defect of all of these mutants was a specific reduction in integrin-independent cell binding to vitronectin. A membrane-tethered plasminogen activator inhibitor-1, which has the same binding site in vitronectin as uPAR, replicated uPAR-induced changes. A direct uPAR–vitronectin interaction is thus both required and sufficient to initiate downstream changes in cell morphology, migration, and signal transduction. Collectively these data demonstrate a novel mechanism by which a cell adhesion molecule lacking inherent signaling capability evokes complex cellular responses by modulating the contact between the cell and the matrix without the requirement for direct lateral protein–protein interactions.
The Ig cell adhesion molecule Basigin controls compartmentalization and vesicle release at Drosophila melanogaster synapses
Authors: Besse Florence , Mertel Sara , Kittel Robert J. , Wichmann Carolin , Rasse Tobias M. , Sigrist Stephan J. , Ephrussi Anne
Published: June 2007

Synapses can undergo rapid changes in size as well as in their vesicle release function during both plasticity processes and development. This fundamental property of neuronal cells requires the coordinated rearrangement of synaptic membranes and their associated cytoskeleton, yet remarkably little is known of how this coupling is achieved. In a GFP exon-trap screen, we identified Drosophila melanogaster Basigin (Bsg) as an immunoglobulin domain-containing transmembrane protein accumulating at periactive zones of neuromuscular junctions. Bsg is required pre- and postsynaptically to restrict synaptic bouton size, its juxtamembrane cytoplasmic residues being important for that function. Bsg controls different aspects of synaptic structure, including distribution of synaptic vesicles and organization of the presynaptic cortical actin cytoskeleton. Strikingly, bsg function is also required specifically within the presynaptic terminal to inhibit nonsynchronized evoked vesicle release. We thus propose that Bsg is part of a transsynaptic complex regulating synaptic compartmentalization and strength, and coordinating plasma membrane and cortical organization.
OMA Browser—Exploring orthologous relations across 352 complete genomes
Authors: Schneider Adrian , Dessimoz Christophe , Gonnet Gaston H.
Published: June 2007

Motivation: Inference of the evolutionary relation between proteins, in particular the identification of orthologs, is a central problem in comparative genomics. Several large-scale efforts with various methodologies and scope tackle this problem, including OMA (the Orthologous MAtrix project).

Results: Based on the results of the OMA project, we introduce here the OMA Browser, a web-based tool allowing the exploration of orthologous relations over 352 complete genomes. Orthologs can be viewed as groups across species, but also at the level of sequence pairs, allowing the distinction among one-to-one, one-to-many and many-to-many orthologs.

Availability:  http://omabrowser.org

Contact:  schneadr@inf.ethz.ch
POODLE-L: a two-level SVM prediction system for reliably predicting long disordered regions
Authors: Hirose Shuichi , Shimizu Kana , Kanai Satoru , Kuroda Yutaka , Noguchi Tamotsu
Published: June 2007

Motivation: Recent experimental and theoretical studies have revealed several proteins containing sequence segments that are unfolded under physiological conditions. These segments are called disordered regions. They are actively investigated because of their possible involvement in various biological processes, such as cell signaling, transcriptional and translational regulation. Additionally, disordered regions can represent a major obstacle to high-throughput proteome analysis and often need to be removed from experimental targets. The accurate prediction of long disordered regions is thus expected to provide annotations that are useful for a wide range of applications.

Results: We developed Prediction Of Order and Disorder by machine LEarning (POODLE-L; L stands for long), the Support Vector Machines (SVMs) based method for predicting long disordered regions using 10 kinds of simple physico-chemical properties of amino acid. POODLE-L assembles the output of 10 two-level SVM predictors into a final prediction of disordered regions. The performance of POODLE-L for predicting long disordered regions, which exhibited a Matthew's correlation coefficient of 0.658, was the highest when compared with eight well-established publicly available disordered region predictors.

Availability: POODLE-L is freely available at http://mbs.cbrc.jp/poodle/poodle-l.html

Contact:  hirose-shuichi@aist.go.jp

Supplementary information: Supplementary data are available at Bioinformatics online.
Hyperthyroidism may affect serum N‐terminal pro‐B‐type natriuretic peptide levels independently of cardiac dysfunction
Authors: Arikan Senay , Tuzcu Alpaslan , Gokalp Deniz , Bahceci Mithat , Danis Ramazan
Published: June 2007

Background and aim  It is known that NT‐proBNP levels increase in cardiac failure. However, NT‐proBNP levels in different thyroid states are still unclear. We aimed to evaluate serum NT‐proBNP levels in both hyperthyroid and hypothyroid patients without cardiac insufficiency.

Subjects and methods  Thirty‐six patients with hyperthyroidism (42·9 ± 16·7 years), 25 patients with hypothyroidism (35·4 ± 13·9 years) and 34 age‐matched euthyroid subjects (41·4 ± 13·8 years) were included in the study. After anthropometric evaluations, body fat analyses were determined by bioelectrical impedance. Electrocardiography and echocardiography were used in cardiac evaluations. Serum NT‐proBNP was measured by immunoassay.

Results  Mean serum NT‐proBNP levels in hyperthyroid patients were higher than in both control subjects (13·65 ± 13·02 vs. 6·50 ± 4·83 pmol/l, P = 0·002) and hypothyroid patients (13·65 ± 13·02 vs. 5·98 ± 5·08 pmol/l, P = 0·003). However, mean serum NT‐proBNP levels in hypothyroid patients were not different from those in control subjects. There was a positive correlation between serum NT‐proBNP and thyroid hormones (NT‐proBNP and FT3: r = 0·324, P = 0·001; NT‐proBNP and FT4: r = 0·269, P = 0·009, respectively). Serum NT‐proBNP levels were positively correlated with left ventricle end‐diastolic diameters (r = 0·232, P = 0·04), interventricular septum thickness (r = 0·315, P = 0·006), and negatively correlated with left ventricular ejection fraction (r = –0·238, P = 0·04).

Conclusions  Serum NT‐proBNP levels may increase in hyperthyroidism independently of cardiac insufficiency. Therefore, hyperthyroidism may lead to cardiac ultrastructural changes undetermined by conventional echocardiography and these changes may be responsible for elevation of NT‐proBNP levels. In contrast to decreased thyroid hormones, excess thyroid hormones may have a more pronounced effect on serum NT‐proBNP levels.
Serum resistin in gestational diabetes mellitus and early postpartum
Authors: Chen Danqing , Fang Qin , Chai Yun , Wang Hanzhi , Huang Hefeng , Dong Minyue
Published: June 2007

Objectives  To observe the alterations in serum resistin in gestational diabetes (GDM) and the early postpartum period, and compare this to nondiabetic pregnancies in order to evaluate the role of serum resistin in gestational diabetes mellitus.

Design  A cross‐sectional study.

Patients  Twenty women with normal pregnancy and 20 with gestational diabetes.

Measurements  Serum resistin concentration was assayed by ELISA.

Results  Serum resistin concentration was significantly higher in women with GDM than in controls before delivery. Serum levels of resistin significantly decreased after delivery in both the GDM group and controls (P < 0·001 for both). There was a trend of higher serum resistin in women with GDM than in controls. Differences existed on days 1 (P < 0·001) and 3 (P = 0·013), but not by day 5 (P = 0·052) after delivery.

Conclusions  Elevated serum resistin level was observed in women with gestational diabetes, suggesting that it is important in the pathology of the disease.
Screening of Cushing's syndrome in adult patients with newly diagnosed diabetes mellitus
Authors: Reimondo Giuseppe , Pia Anna , Allasino Barbara , Tassone Francesco , Bovio Silvia , Borretta Giorgio , Angeli Alberto , Terzolo Massimo
Published: June 2007

Objective  Recent studies have shown that a relatively high number of diabetic patients may have unsuspected Cushing's syndrome (CS). The aim of the present study was to screen for CS in adult patients with newly diagnosed diabetes mellitus who were not selected for clinical characteristics, such as poor control and obesity, which may increase the pre‐test probability of CS.

Design, patients and measurement  We prospectively evaluated 100 consecutive diabetic patients at diagnosis from 2003 to 2004. No patient had clear Cushingoid features. Screening was performed by using the overnight 1‐mg dexamethasone suppression test (DST) after complete recovery from acute concomitant illnesses and attainment of satisfactory glycaemic control. The threshold of adequate suppression after DST was set at 110 nmol/l.

Results  Five patients failed to suppress cortisol after DST and underwent a repeated DST and a confirmatory standard 2‐day, 2‐mg DST after 3–6 months from the baseline evaluation. In one woman, a definitive diagnosis of CS was made by a surgically proven pituitary adenoma, and glycaemic control improved after cure of CS.

Conclusions  The results of the present study support the view that unknown CS is not rare among patients with diabetes mellitus. This is the first demonstration that screening for CS may be feasible at the clinical onset of diabetes in an unselected cohort of patients. Therefore, early diagnosis and treatment of CS may provide the opportunity to improve the prognosis of diabetes.
Age‐, gender‐, and weight‐related effects on levels of 25‐hydroxyvitamin D are not mediated by vitamin D binding protein
Authors: Bolland Mark J. , Grey Andrew B. , Ames Ruth W. , Horne Anne M. , Mason Barbara H. , Wattie Diana J. , Gamble Greg D. , Bouillon Roger , Reid Ian R.
Published: June 2007

Objective  25‐hydroxyvitamin D (25OHD) levels are inversely related to body weight, and have been reported to decline with age and be lower in women than men. We hypothesized that these findings might be explained by effects of these variables on vitamin D binding protein (DBP) levels. We set out to determine the relationships between DBP and gender, 25OHD, body weight and body composition.

Design  Cross‐sectional analysis.

Patients  One hundred healthy, middle‐aged and older, community‐dwelling men and women.

Measurements  All participants were measured for 25OHD, DBP, body weight, bone mineral density and body composition.

Results  Women had higher mean DBP levels than men but lower total 25OHD levels [DBP: women, mean (SD) 339 (36) mg/l, men 307 (71) mg/l, P = 0·005; 25OHD: women 67 (23) nmol/l, men 91 (39) nmol/l, P < 0·001]. In women, there were significant positive relationships between DBP and albumin (r = 0·33) and 25OHD (r = 0·34) whereas in men there were no significant relationships between DBP and any measured variables. There was no significant relationship between DBP and age, body weight, body mass index, fat mass or percentage fat in men or women.

Conclusion  We found no evidence to support the hypothesis that DBP levels are related to age, or adiposity. The changes in 25OHD levels with age, gender, or fat mass are not due to underlying relationships between DBP and these variables. This suggests that the relationships consistently observed between 25OHD and body composition and gender are of biological origin and not due to adaptation to changes in transport proteins.
Bone mineral density remains stable in HAART‐treated HIV‐infected men over 2 years
Authors: Bolland Mark J. , Grey Andrew B. , Horne Anne M. , Briggs Simon E. , Thomas Mark G. , Ellis‐Pegler Rod B. , Woodhouse Andrew F. , Gamble Greg D. , Reid Ian R.
Published: June 2007

Objective  Recently we reported that human immunodeficiency virus (HIV)‐infected Caucasian men treated with highly active antiretroviral therapy (HAART) have normal weight‐adjusted bone mineral density (BMD), in contrast to most other cross‐sectional analyses, which have reported low BMD in HIV‐infected patients. We have now addressed the question of whether there is accelerated BMD loss over time in HIV‐infected men.

Design  A 2‐year, prospective, longitudinal study.

Subjects  Twenty‐three HAART‐treated, HIV‐infected men and 26 healthy controls.

Measurements  All participants had measurements of BMD and bone‐related laboratory parameters at baseline, and a repeat measurement of BMD at 2 years.

Results  In the HIV‐infected men the mean age was 47 years, the mean duration of infection was 8·2 years, and the mean duration of HAART was 54 months. Over 2 years of follow‐up, BMD increased from baseline in the HIV‐infected men by 2·6% at the lumbar spine (P = 0·05 vs. baseline), and remained stable at the total hip (mean change 0·1%, P > 0·99) and total body (mean change 0·6%, P = 0·39). Mean changes in BMD in the control group were 1·4% at the lumbar spine, –0·1% at the total hip, and –0·8% at the total body. The HIV‐infected men lost less total body BMD than the control group (P = 0·01). In the HIV‐infected men, body weight remained stable over 2 years while fat mass decreased and lean mass tended to increase, whereas in the controls, body weight and fat mass increased while lean mass remained stable.

Conclusions  Accelerated bone loss does not occur in HIV‐infected men treated with HAART. Monitoring of BMD in HIV‐infected men may not be necessary.
Differences in morphological and physiological traits between native and invasive populations of Sapium sebiferum
Authors: ZOU J. , ROGERS W. E. , SIEMANN E.
Published: June 2007

Functional traits contribute to the success of invasive plants. These traits can reflect inherent properties or they can be new adaptations from evolutionary responses to escape from natural enemies of the introduced range. We tested the hypothesis that genetic shifts in morphological and physiological traits have occurred between native and invasive populations of Sapium sebiferum.

Sapium sebiferum seedlings were grown in a greenhouse using seed collected from four populations of its introduced range (US) and four from native Chinese populations that are thought to be genetic candidates of the introduced populations. We examined plant biomass production, relative growth rate (RGR), relative stem height growth rate (RHR), root : shoot ratio (RSR), total number of leaves (TLN) and leaf area (TLA), specific leaf area (SLA), leaf area ratio (LAR), net CO2 assimilation (A) and shoot specific respiration rate (RD).

US populations of S. sebiferum differed from Chinese populations for most plant variables. Final shoot and total biomass, as well as, RGRs of invasive (US) populations were significantly greater than those of native (Chinese) populations, although RHR and TLN per seedling did not differ between them. Root : shoot ratios (RSR) were significantly lower, while leaf traits including TLA, LAR and SLA were generally greater for invasive populations compared to native populations. Net CO2 A was significantly higher for invasive populations than for native populations, but no significant difference in RD was found between two population types.

Of 13 measured plant variables, RSRs, TLA and CO2 A were identified as traits that contributed the most to differences observed between native Chinese and invasive US populations. The suite of morphological and physiological traits functioning together may result in different growth strategies for native versus invasive populations. By virtue of these traits, invasive populations of S. sebiferum may use soil resources and light more efficiently than native populations, which may have given rise to their competitive superiority in the introduced range.
Evaluation of dirlotapide for sustained weight loss in overweight Labrador retrievers
Authors: GOSSELLIN J. , PEACHEY S. , SHERINGTON J. , ROWAN T. G. , SUNDERLAND S. J.
Published: June 2007

The effects of dirlotapide on body weight (BW) reduction were investigated in overweight Labradors in two parallel‐design studies. Study A involved 42 dogs randomized to 0.0, 0.025, 0.05, 0.1, 0.2 or 0.4 mg dirlotapide/kg/day orally for 4 weeks. Study B involved 72 dogs randomized to nine treatments: placebo (24 weeks); dirlotapide (24 weeks) followed by placebo (28 weeks); or dirlotapide (52 weeks); on diets containing 5%, 10% or 15% fat. Dirlotapide dose (initially 0.1 mg/kg) was adjusted monthly during 24‐week weight‐loss and subsequent 28‐week weight‐stabilization phases. Food was offered above maintenance energy requirements (MER× 1.1–1.2) based on initial BW. Body composition (body fat, lean tissue and bone mineral content) was monitored using dual‐energy X‐ray absorptiometry. After treatment, dogs that had received dirlotapide for 52 weeks were fed 90% of quantity consumed at week 52. In study A, BW and food intake decreased asymptotically with dose: mean weekly weight loss exceeded 1% at 0.1–0.4 mg/kg. In study B, dirlotapide resulted in significant mean weekly weight loss (>0.8%) and decreased food intake over 24 weeks compared with placebo (P = 0.0001) for all diets. Food restriction minimized post‐treatment weight rebound. Dirlotapide administered daily to dogs for up to 52 weeks was clinically safe and resulted in sustained weight reduction.
Clonal diversity of a lizard malaria parasite, Plasmodium mexicanum, in its vertebrate host, the western fence lizard: role of variation in transmission intensity over time and space
Authors: VARDO A. M. , SCHALL J. J.
Published: June 2007

Within the vertebrate host, infections of a malaria parasite (Plasmodium) could include a single genotype of cells (single‐clone infections) or two to several genotypes (multiclone infections). Clonal diversity of infection plays an important role in the biology of the parasite, including its life history, virulence, and transmission. We determined the clonal diversity of Plasmodium mexicanum, a lizard malaria parasite at a study region in northern California, using variable microsatellite markers, the first such study for any malaria parasite of lizards or birds (the most common hosts for Plasmodium species). Multiclonal infections are common (50–88% of infections among samples), and measures of genetic diversity for the metapopulation (expected heterozygosity, number of alleles per locus, allele length variation, and effective population size) all indicated a substantial overall genetic diversity. Comparing years with high prevalence (1996–1998 = 25–32% lizards infected), and years with low prevalence (2001–2005 = 6–12%) found fewer alleles in samples taken from the low‐prevalence years, but no reduction in overall diversity (H = 0.64–0.90 among loci). In most cases, rare alleles appeared to be lost as prevalence declined. For sites chronically experiencing low transmission intensity (prevalence ~1%), overall diversity was also high (H = 0.79–0.91), but there were fewer multiclonal infections. Theory predicts an apparent excess in expected heterozygosity follows a genetic bottleneck. Evidence for such a distortion in genetic diversity was observed after the drop in parasite prevalence under the infinite alleles mutation model but not for the stepwise mutation model. The results are similar to those reported for the human malaria parasite, Plasmodium falciparum, worldwide, and support the conclusion that malaria parasites maintain high genetic diversity in host populations despite the potential for loss in alleles during the transmission cycle or during periods/locations when transmission intensity is low.
Rates, types, and psychosocial correlates of legal charges in adolescents with newly diagnosed bipolar disorder
Authors: Barzman Drew H , DelBello Melissa P , Fleck David E , Lehmkuhl Heather , Strakowski Stephen M
Published: June 2007

Objectives:  To examine the rates, types, and psychosocial correlates of legal charges in adolescents with newly diagnosed bipolar disorder (BD).

Methods:  Adolescents (n = 80), between the ages of 12 and 21 years (mean = 15.6, standard deviation = 2.3), hospitalized for their initial manic or mixed episode of BD, were evaluated for the incidence of prior juvenile offending (i.e., legal charges). We examined potential psychosocial correlates associated with legal charges using chi‐square, t‐tests, and discriminant function analyses to determine if there were differences between adolescents who did and did not offend prior to their first manic episode.

Results:  Juvenile antisocial behaviors were common (55%) for adolescents with newly diagnosed BD. Discriminant function analysis revealed that older age at first treatment (p < 0.01), sexual activity over the previous month (p < 0.05), therapeutic use of stimulants (p < 0.05), and anxiety disorders were the most significant factors to differentiate between bipolar adolescents who offended and those who did not (Wilks’ lambda = 0.80, p < 0.005).

Conclusions:  Our findings indicate that there are identifiable psychosocial correlates associated with antisocial behaviors in adolescents with newly diagnosed BD that may improve our understanding of juvenile antisocial behaviors.
Diagnosing bipolar disorder in trauma exposed primary care patients
Authors: Graves Ruth Elaine , Alim Tanya N , Aigbogun Notalelomwan , Chrishon Kris , Mellman Thomas A , Charney Dennis S , Lawson William B
Published: June 2007

Objectives:  Bipolar disorder (BD) is often under‐recognized in non‐psychiatric settings, especially in African Americans. The Mood Disorder Questionnaire (MDQ) is a screening instrument proposed to show adequate sensitivity and specificity for bipolar spectrum disorders. The current study is an examination of the usefulness of this instrument in a trauma exposed subgroup of mainly African American patients attending primary care clinics.

Methods:  The sample is a part of a larger study exploring traumatic stress exposure and psychopathology. Consenting patients in 3 academically affiliated primary care clinics were asked to complete the MDQ. Ninety percent of the participants were African American. Diagnostic performance was determined in a trauma exposed subgroup by employing the Structured Clinical Interview for DSM‐IV (SCID) as a gold standard.

Results:  Of the total group of 579 participants, 178 (30.7%) screened positive for BD along with 77 (33.7%) of the 228 trauma exposed subjects who were SCID interviewed. Only 13 (27%) of the MDQ positives met SCID criteria for BD and were true positives. The sensitivity was 61.9% and the specificity was 69%, with a positive predictive value of 16.8% and a negative predictive value of 94.7%.

Conclusions:  The MDQ was found to have low specificity in a predominately African American group of trauma exposed patients attending primary care.
Quetiapine monotherapy in the treatment of patients with bipolar I or II depression and a rapid‐cycling disease course: a randomized, double‐blind, placebo‐controlled study
Authors: Vieta E , Calabrese JR , Goikolea JM , Raines S , Macfadden W ,   for the BOLDER Study Group
Published: June 2007

Objectives:  To investigate the efficacy and tolerability of quetiapine monotherapy in patients with bipolar I or II disorder with a rapid‐cycling disease course.

Methods:  Adult patients with a DSM‐IV diagnosis of bipolar disorder, most recent episode depressed, with a rapid‐cycling disease course from a previously completed multicenter trial randomized to 8 weeks of treatment with quetiapine 600 mg/day (n = 31), quetiapine 300 mg/day (n = 42), or placebo (n = 35) were included in this sub‐analysis. The primary efficacy variable was change from baseline to week 8 in Montgomery–Asberg Depression Rating Scale (MADRS) total score.

Results:  Quetiapine (600 and 300 mg/day) provided significantly greater mean reductions from baseline to week 8 in the MADRS total score than placebo (−21.1, −20.7 versus −11.6, both p < 0.001) in this patient population. Effect sizes in patients with a rapid‐cycling disease course were 1.2 (600 mg/day) and 1.1 (300 mg/day) and were similar for bipolar I (0.98 and 1.22) and bipolar II (1.45 and 0.97) sub‐groups. Significant improvements were also noted on the Clinical Global Impression, Hamilton Rating Scale for Depression, Hamilton Rating Scale for Anxiety, Pittsburgh Sleep Quality Index, and Quality of Life Enjoyment and Satisfaction Questionnaire scales. Quetiapine was generally well tolerated with moderate increases in weight and extrapyramidal side effects compared to placebo. The incidence of treatment‐emergent mania was similar to placebo.

Conclusions:  Quetiapine monotherapy (600 or 300 mg/day) is clinically effective and well tolerated in the short‐term treatment of depressive episodes in patients with bipolar I or II disorder who have a rapid‐cycling disease course.
Effectiveness of mood stabilizers and antipsychotics in the maintenance phase of bipolar disorder: a systematic review of randomized controlled trials
Authors: Smith Lesley A , Cornelius Victoria , Warnock Adrian , Bell Angus , Young Allan H
Published: June 2007

Background:  Bipolar disorder (BD) is a leading cause of disability. Systematic reviews of randomized trials for the treatment of the maintenance phase of BD are lacking.

Objectives:  To determine the efficacy and tolerability of mood stabilizers and antipsychotics in the maintenance treatment of BD.

Methods:  We systematically reviewed randomized controlled trials of licensed medications for the treatment of any phase of BD. We included randomized controlled trials comparing a medication to placebo or another medication. Comprehensive searches of electronic databases were conducted to March 2005. Outcomes investigated were relapse due to mania, depression or any mood episode, and withdrawal due to any reason or due to an adverse event. Data were combined through meta‐analysis.

Results:  Fourteen studies (n = 2,526) met the inclusion criteria. Lithium, lamotrigine, olanzapine and valproate semisodium each demonstrated evidence to support long‐term use. Compared with placebo, all medications were more effective at preventing relapse because of any mood episode. Hazard ratios (HR) were 0.68 [95% confidence interval (CI) = 0.53–0.86] for lithium, 0.68 (95% CI = 0.55–0.85) for lamotrigine, and 0.82 (95% CI = 0.57–1.20) for valproate semisodium; for olanzapine, the risk ratio (RR) was 0.58 (95% CI = 0.49–0.69). Lithium and olanzapine significantly reduced manic relapses (HR = 0.53; 95% CI = 0.35–0.79 and RR = 0.37; 95% CI = 0.24–0.57, respectively). Lamotrigine and valproate semisodium significantly reduced depressive relapses (HR = 0.65; 95% CI = 0.46–0.91 and RR = 0.40; 95% CI = 0.20–0.82, respectively). Lithium significantly reduced manic relapses compared with lamotrigine (HR = 0.56; 95% CI = 0.34–0.92) and olanzapine significantly reduced manic relapses compared with lithium (RR = 1.69; 95% CI = 1.12–2.55). Withdrawal due to an adverse event was approximately twice as likely with lithium compared with valproate semisodium (RR = 1.81; 95% CI = 1.08–3.03) and lamotrigine (RR = 2.20; 95% CI = 1.31–3.70). There were few data for carbamazepine or medications given as adjunct therapy.

Conclusions:  Mood stabilizers have differing profiles of efficacy and tolerability, suggesting complementary roles in long‐term maintenance treatment.
Effects of crop type on Bacillus thuringiensis toxicity and residual activity against Trichoplusia ni in greenhouses
Authors: Janmaat A. F. , Ware J. , Myers J.
Published: June 2007

We assessed the efficacy and persistence of a Bacillus thuringiensiskurstaki (Btk) formulation (Dipel) against Trichoplusia ni (Hubner) (Lep., Noctuidae), the cabbage looper, on three greenhouse vegetable crops (tomato, bell pepper and cucumber). First, T. ni larvae were fed leaf discs treated with Btk to assess how Btk toxicity varies with host plant. Secondly, T. ni larvae were fed leaf discs harvested from plants that had been sprayed with Btk 1, 5 and 9 days previously to assess the residual activity of Btk toxicity in greenhouse environments. Mortality of T. ni larvae fed tomato leaf discs was significantly higher than T. ni fed cucumber or pepper leaf discs. The toxicity of Btk had declined by less than 50% after 9 days, which suggests that Btk persistence is lengthy in greenhouse environments. No crop effects on the residual activity of Btk were found. These results demonstrate that the greenhouse environment and the crop should be considered when using Btk for insect management on greenhouse crops.
Withholding anticoagulation after a negative computed tomography pulmonary angiogram as a stand‐alone imaging investigation: a prospective management study
Authors: Subramaniam R. M. , Blair D. , Gilbert K. , Coltman G. , Sleigh J. , Karalus N.
Published: June 2007

Background: Accurate diagnosis of pulmonary embolism (PE) is essential and it is not clear whether a computed tomography pulmonary angiogram (CTPA) could be used as a stand‐alone imaging investigation. The aim of the study was to test the accuracy of the clinical outcome of a negative CTPA as a stand‐alone imaging investigation to exclude PE.

Methods: Five hundred and thirty‐four consecutive patients who had a CTPA for diagnosis or exclusion of PE were recruited from March 2003 to October 2004. Four hundred and ninety‐four patients had a helical CTPA as a stand‐alone imaging investigation for diagnosis or exclusion of PE. A 3‐month post‐CTPA follow up was carried out in all patients to establish the clinical outcome accuracy of a negative CTPA as a stand‐alone imaging investigation.

Results: There were 387 (78.3%) negative and 107 (21.7%) positive CTPA examinations. The average age of the patients was 57.16 years (standard deviation 18.57). Among those with a negative CTPA who survived, one patient had deep vein thrombosis and 342 patients had no evidence of an episode of venous thromboembolism or PE at the 3‐month follow up. Thirty‐eight patients died within the 3‐month follow‐up period and one patient’s death was attributed to suspected PE. The negative predictive value of a CTPA is 99.5% (95% confidence interval 98.1–99.9%).

Conclusion: Helical negative CTPA examination excludes clinically significant PE as a stand‐alone imaging investigation. Where concurrent deep vein thrombosis is suspected, lower limb needs to be imaged by ultrasound if the CTPA is negative.
D‐dimer concentration increases with age reducing the clinical value of the D‐dimer assay in the elderly
Authors: Harper P. L , Theakston E. , Ahmed J. , Ockelford P.
Published: June 2007

Background: The D‐dimer assay is used as an exclusion test in the assessment of suspected venous thromboembolic disease; patients with a negative result have a low probability of thrombosis. We reviewed the D‐dimer results from a hospital and community laboratory using the vidas D‐dimer test to assess the influence of age on the D‐dimer assay.

Methods: D‐dimer results from 6631 unselected patients aged more than 16 years were analysed in four age groups and it was shown that the median D‐dimer concentration increased with age (16–40 years, 294 ng/mL; 40–60 years, 387 ng/mL; 60–80 years; 854 ng/mL; >80 years, 1397 ng/mL). To test the effect of age on the assay specificity, a cohort of 1897 patients with suspected venous thromboembolic disease was analysed separately. Patients with a negative D‐dimer were discharged without further investigation. Patients with a positive result and a clinical suspicion of thrombosis underwent further investigation. One hundred and sixty‐five deep vein thrombosis or pulmonary embolus cases were identified.

Results: The assay specificity decreased with age from 70% in patients less than 40 years to below 5% in patients more than 80 years. Receiver operator curves were prepared for each age group and the effect of altering the threshold value was analysed. In patients 60–80 years old a threshold value of 1000 ng/mL increased assay specificity to 55% without loss of assay sensitivity.

Conclusion: The vidas D‐dimer assay with a threshold value of 500 ng/mL has little clinical value as an exclusion test in patients more than 80 years old. The assay specificity is poor (26%) in patients aged 60–80 years but could be improved by increasing the threshold value to 1000 ng/mL. We believe that this should be tested in a prospective trial.
Pointing Sets the Stage for Learning Language—and Creating Language
Authors: Goldin‐Meadow Susan
Published: June 2007

Tomasello, Carpenter, and Liszkowski (2007) have argued that pointing gestures do much more than single out objects in the world. Pointing gestures function as part of a system of shared intentionality even at early stages of development. As such, pointing gestures form the platform on which linguistic communication rests, paving the way for later language learning. This commentary provides evidence that pointing gestures do establish a foundation for learning a language and, moreover, set the stage for creating a language.