bluuebunny/crossref_metadata_2025 huggingface dataset:
FRACTURE CHARACTERISTICS OF BOROSILICATE GLASSES REINFORCED BY METALLIC PARTICLES
Authors: Dlouhy I. , Reinisch M. , Boccaccini A. R. , Knott J. F.
Published: February 2008

Abstract— The fracture behaviour of borosilicate glass reinforced by molybdenum and/or vanadium particles has been investigated. For the addition of 5 vol% molybdenum particles, two processing procedures have been tested and the influence of volume fraction of vanadium particles (in the range 2 to 30 vol%) on fracture resistance has been assessed. The use of chevron‐notched specimens in three‐point bending has been shown to be a reliable method for the evaluation of fracture toughness even at toughness levels of order 0.7 to 1.3 MPa √m. The existence of subtle differences in fracture behaviour of glass‐composites having comparable volume fractions of molybdenum particles but obtained by two different processing procedures has been established by statistical treatment of the fracture toughness data. An increase in the volume fraction of metallic particles results in an increase of the fracture resistance and the measured fracture toughness level. Toughening mechanisms which have been identified include both the plastic deformation of particles and the bridging of cracks by ductile particles. Some particle cleavage and debonding has been observed, which indicates that a decrease in particle plasticity, probably induced by processing or due to constraints imposed by the rigid matrix, is responsible for a smaller than expected enhancement of the fracture toughness.
THE MINIATURISATION OF THE 4‐POINT‐BEND TEST
Authors: Lube T. , Manner M. , Danzer R.
Published: February 2008

Abstract— Strength measurements are becoming increasingly important for electroceramics. Bending of specimens small enough to be cut out of small electroceramic components may be one possibility. Therefore the miniaturisation of the 4‐point bend‐test for ceramic specimens is now being attempted. In this paper the errors in determining the flexural strength arising from the test principle itself, plus the geometry and measuring inaccuracies are calculated and expressed as a function of the outer span length. Contact pressure and a tolerable total measuring inaccuracy determines the dimensions of miniature specimens and fixtures. The possibilities of appropriate specimen preparation are also investigated.

Ceramic materials show a volume (i.e. a specimen size) dependence of strength which is described by Weibull's statistical theory. The applicability of the miniature bend‐fixtures is demonstrated by measuring this volume effect.
Modernity, ‘authenticity’, and ambivalence: subaltern masculinities on a South Indian college campus
Authors: Rogers Martyn
Published: February 2008

Focusing on an inner‐city college in Chennai, Tamil Nadu, South India, the article investigates the sexual harassment of female students. Locating this violence within the context of social changes resulting from India's integration into the global economy, the article argues that, in this context, sexual harassment is a manifestation of instrumental violence, deployed by subaltern or Scheduled Caste youths to contest their subordination within higher education and the ‘white‐collar’ employment market. However, this contest reveals a number of ambivalences through which these subaltern masculinities are constituted. Rationalizing their sexual harassment, the protagonists’ narratives, therefore, oscillate between denigrating ‘Westernization’ while valorizing Tamil culture ideals, and vice versa. This conflict is centred on intense competition for male privilege and status between the newly emerged middle‐class elite and impoverished low‐caste groups, effectively reworking the social history of youth masculinity to meet the demands of new economic and political conditions.

À partir du cas d’un collège urbain de Chennai dans le Tamil Nadu, dans le sud de l’Inde, le présent article étudie le harcèlement sexuel des étudiantes. En resituant cette violence dans le cadre des changements sociaux résultant de l’intégration de l’Inde dans l’économie mondiale, l’auteur affirme que dans ce contexte, le harcèlement sexuel est une manifestation de violence instrumentalisée par les jeunes hommes des castes subalternes ou répertoriées (scheduled) pour contester leur subordination sur le marché de l’éducation supérieure et de l’ emploi « en col blanc ». Cette rivalité révèle toutefois un certain nombre d’ambivalences par lesquelles ces masculinités subalternes se constituent. Les récits de protagonistes oscillent donc, pour justifier leur harcèlement sexuel, entre le dénigrement de « l’occidentalisation » associéà l’exaltation des idéaux culturels tamouls et vice versa. Ce conflit se cristallise dans une compétition intense à propos des prérogatives et du statut masculins entre la nouvelle élite des classes moyennes émergentes et les basses castes appauvries. De fait, il revisite l’histoire sociale de la masculinité des jeunes gens dans l’optique des nouvelles conditions économiques et politiques.
A preliminary study comparing the endometrial expression of inhibin, activin and follistatin in women with a history of implantation failure after IVF treatment and a control group
Authors: Prakash A , Tuckerman E , Laird S , Ola B , Li TC , Ledger WL
Published: February 2008

The aim of this study was to evaluate the expression of activin: beta A and beta B subunit and follistatin in endometrium of women with implantation failure (n = 10) and compare it with a fertile control group (n = 7). Immunohistochemical staining intensity for follistatin in the endometrial glandular epithelium from women with implantation failure were significantly lower than that in control women (P = 0.03). The decreased expression of follistatin in epithelial cells in the endometrium of women with implantation failure after in vitro fertilisation (IVF) may suggest that follistatin may play a role in the implantation process.
Life events in patients with vulvodynia
Authors: Plante AF , Kamm MA
Published: February 2008

Objective  Vulval pain, in the absence of pathology, may have a psychological basis that relates to life events. This study aimed to determine the nature of such events.

Design  Structured questionnaire about patient’s symptoms and early‐life events.

Setting  Private practice physiotherapist specialising in pelvic floor disorders.

Population  Patients with vulvodynia as their primary symptom and control patients being treated for urinary tract disorder or post‐childbirth routine physiotherapy who had no vulval pain on direct questioning.

Methods  Questionnaire applied to consecutive patients referred for treatment. Seventy‐eight consecutive women presenting with vulvodynia (mean age 34 years, mean duration of symptoms 48 months) and 78 controls (mean age 39 years).

Main outcome measures  Incidence of life events.

Results  A similar proportion of both groups were married. Being in a new relationship (P < 0.04), adverse current or previous relationships (39 versus 9%, P ≤ 0.01), parental divorce (26 versus 9%, P ≤ 0.001), history of termination of pregnancy, and adverse childbirth experiences (P < 0.04) were more common in patients than in controls. A history of sexual abuse was not more common in patients with vulvodynia compared with controls (13 versus 10%, P = not significant). Lack of libido was common in patients with vulvodynia (94 versus 29%, P < 0.0001).

Conclusions  Adverse life experiences, including conflict, are common in women with vulvodynia. These factors may be important in mediating the genesis of pain through stress‐related mechanisms. Sexual interest is diminished in these women. Sexual abuse is not a factor in most of these women. These findings have implications for treatment.
MORPHOLOGICAL AND PHYLOGENETIC STUDIES ON UNICELLULAR DIAZOTROPHIC CYANOBACTERIA (CYANOPHYTES) ISOLATED FROM THE COASTAL WATERS AROUND SINGAPORE1
Authors: Ohki Kaori , Kamiya Mitsunobu , Honda Daisuke , Kumazawa Shuzo , Ho Kwok Ki
Published: February 2008

Six unicellular diazotrophic cyanobacteria were isolated from the coast around Singapore. The isolates grew under both light:dark (L:D) cycles and continuous illumination (CL) in media without combined nitrogen and exhibited an ability to fix nitrogen (as measured by acetylene reduction) under aerobic conditions. The cells of all isolates were surrounded by a thick fibrous outer wall layer, and they divided by transverse binary fission. The arrangement of photosynthetic thylakoids was of the dispersed type. Three isolates were identified as form‐genus Gloeothece as cells were divided in a single plane, and the other three isolates were identified as form‐genus Gloeocapsa as cells were divided in multiple planes. Phylogenetic analyses based on the DNA sequences of the genes encoding 16S rRNA and dinitrogenase reductase (nifH) revealed the following: (i) Our six isolates formed a monophyletic cluster. (ii) The monophyletic cluster was subdivided into two phylogenetic groups, which taxonomically corresponded with the form‐genera Gloeothece and Gloeocapsa. However, (iii) a diazotrophic strain of form‐genus Gloeothece, Gloeothece membranacea (Rabenh.) Bornet PCC6501, was not closely related to our isolates, and (iv) some, but not all, diazotrophic unicellular strains of form‐genus Cyanothece were observed to be in a close relationship with our isolates.
GENOMIC INSIGHTS INTO EVOLUTIONARY RELATIONSHIPS AMONG HETEROKONT LINEAGES EMPHASIZING THE PHAEOPHYCEAE1
Authors: Phillips Naomi , Calhoun Samantha , Moustafa Ahmed , Bhattacharya Debashish , Braun Edward L.
Published: February 2008

Heterokonts comprise a large and diverse group of organisms unified by the heterokont biflagellate condition. Monophyly of many of these lineages is well established, but evolutionary relationships among the various lineages remain elusive. Among these lineages, the brown algae (Phaeophyceae) are a monophyletic, taxonomically diverse, and ecologically critical group common to marine environments. Despite their biological and scientific importance, consensus regarding brown algal phylogeny and taxonomic relationships is missing. Our long‐term research goal is to produce a well‐resolved taxon‐rich phylogeny of the class to assess evolutionary patterns and taxonomic relationships among brown algal lineages and their relationship to other closely related heterokont groups. To accomplish this goal and augment existing loci for phaeophycean‐wide systematic studies, we generated expressed sequence tags (ESTs) from several major brown algal lineages and from the heterokont lineage representing the closest sister group to brown algae. To date, we have successfully constructed cDNA libraries for two lineages (Choristocarpus tenellus Zanardini and Schizocladia ischiensis E. C. Henry, Okuda et H. Kawai) and in the library test phase obtained up to 1,600 ESTs per organism. Annotation results showed a gene discovery rate of 45%–50% for each library revealing 500–700 unique genes from each organism. We have identified several potential genes for phylogenetic inference and used these loci for preliminary molecular clock analyses. Our molecular clock analysis suggests that the basal divergence in brown algae occurred around the time of the pennate‐centric diatom divergence. Here we report this analysis and other uses of ESTs in brown algal phylogenomics and the utility of these data for resolving the phylogeny of this group.
BICARBONATE STIMULATION OF CALCIFICATION AND PHOTOSYNTHESIS IN TWO HERMATYPIC CORALS1
Authors: Herfort Lydie , Thake Brenda , Taubner Isabelle
Published: February 2008

A wide range of bicarbonate concentrations was used to monitor the kinetics of bicarbonate (HCO3−) use in both photosynthesis and calcification in two reef‐building corals, Porites porites and Acropora sp. Experiments carried out close to the P. porites collection site in Barbados showed that additions of NaHCO3 to synthetic seawater proportionally increased the calcification rate of this coral until the concentration exceeded three times that of seawater (6 mM). Photosynthetic rates were also stimulated by HCO3− addition, but these became saturated at a lower concentration (4 mM). Similar experiments on aquarium‐acclimated colonies of Indo‐Pacific Acropora sp. showed that calcification and photosynthesis in this coral were enhanced to an even greater extent than P. porites, with calcification continuing to increase above 8 mM HCO3−, and photosynthesis saturating at 6 mM. Calcification rates of Acropora sp. were also monitored in the dark, and, although these were lower than in the light for a given HCO3− concentration, they still increased dramatically with HCO3− addition, showing that calcification in this coral is light stimulated but not light dependent.
ANTIFEEDING DEFENSE IN BALTIC MACROALGAE: INDUCTION BY DIRECT GRAZING VERSUS WATERBORNE CUES1
Authors: Rohde Sven , Wahl Martin
Published: February 2008

The prevalence of antigrazing defense induction and the cues triggering induction in marine macroalgae are generally not well understood. We examined the capacity of defense and the mechanisms of regulation in five common perennial macroalgal species from the Baltic Sea, Furcellaria lumbricalis (Huds.) J. V. Lamour., Delesseria sanguinea (Huds.) J. V. Lamour., Phyllophora pseudoceranoides (S. G. Gmel.) Newroth et A. R. A. Taylor, Fucus serratus L., and Fucus evanescens C. Agardh. Specifically, we investigated whether direct feeding and/or waterborne cues from feeding on neighboring conspecifics decreased the palatability of the tested algae. Direct feeding by the local isopod Idotea baltica triggered the induction of chemical defense in Fur. lumbricalis, D. sanguinea, P. pseudoceranoides, F. serratus, and F. evanescens. Conversely, we did not find any evidence for waterborne cues associated with feeding to trigger defense induction in neighboring conspecifics.
Prosthetic Rehabilitation of Orofacial Donor Site Fistula Following Surgical Reconstruction: A Clinical Report
Authors: Kumar T. Pavan , Azhagarasan N.S. , Shankar K. Chitra , Rajan Manoj
Published: February 2008

Orofacial defects can be either congenital or acquired. Rehabilitation of these patients can be done using a surgical and/or a prosthetic approach. In situations where surgical reconstruction is not possible, prosthetic management becomes the only option. This clinical report describes a simple, economical, and effective technique for the prosthetic rehabilitation of a patient with oro‐cutaneous fistula due to donor site dehiscence following tumor defect reconstruction.
Inducibility of Paroxysmal Atrial Fibrillation by Isoproterenol and its Relation to the Mode of Onset of Atrial Fibrillation
Authors: ORAL HAKAN , CRAWFORD THOMAS , FREDERICK MELISSA , GADEELA NITESH , WIMMER ALAN , DEY SUJOYA , SARRAZIN JEAN F. , KUHNE MICHAEL , CHALFOUN NAGIB , WELLS DARRYL , GOOD ERIC , JONGNARANGSIN KRIT , CHUGH AMAN , BOGUN FRANK , PELOSI FRANK , MORADY FRED
Published: February 2008

Background: Isoproterenol has been used to assess inducibility during catheter ablation for paroxysmal PAF. However, no studies have determined the sensitivity and specificity of isoproterenol for the induction of AF. It also is not clear whether isoproterenol is equally effective in inducing AF in the clinical subtypes of vagotonic, adrenergic, and random AF.

Objective: To determine the sensitivity and specificity of isoproterenol for the induction of atrial fibrillation (AF).

Methods: Isoproterenol was infused at 5, 10, 15, and 20 μg/min at 2‐minute intervals or until AF was induced in 20 control subjects with no history of AF and in 80 patients with PAF.

Results: Among the 20 control subjects, AF was induced by isoproterenol in one patient (5%). Among the 80 patients with PAF, persistent AF was induced in 67 patients (84%, P < 0.001). Isoproterenol induced AF in 15 of 17 patients (88%) with vagotonic AF, 11 of 11 patients (100%) with adrenergic AF, and 41 of 52 patients (79%) with random episodes of AF (P = 0.2). The yield of AF was 11% (9/80) after 5 μg/min, 28% (22/80) after 10 μg/min, 51% (40/78) after 15 μg/min, and 88% (67/76) after 20 μg/min of isoproterenol (P < 0.01). Isoproterenol had to be discontinued in four patients (5%) before reaching the maximum dose due to reversible chest pain or systolic blood pressure <85 mmHg.

Conclusions: Isoproterenol at infusion rates up to 20 μg/min has a high sensitivity (88%) and specificity (95%) for induction of AF in patients with PAF, regardless of whether the clinical subtype is vagotonic, adrenergic, or random.
Health‐related quality of life in the era of erythropoietin
Authors: WEISBORD Steven D. , KIMMEL Paul L.
Published: February 2008

Patients with end‐stage renal disease treated with maintenance hemodialysis suffer substantial impairments in health‐related quality of life (HRQOL). Despite widespread efforts, there are few interventions that improve the overall well‐being and quality of life of this patient population. The current review provides a description of HRQOL as an essential, yet arguably overlooked health‐related domain in hemodialysis patients, and discusses interventions that have been evaluated to improve the functional status and well‐being of this population, with a particular focus on therapy with recombinant human erythropoietin. We review the controversy surrounding recombinant human erythropoietin as it relates to HRQOL, and describe the delicate balance faced by renal providers who seek to reduce hemodialysis patients' morbidity and mortality while simultaneously striving to improve patients' HRQOL.
Hemodialysis: A therapeutic option for severe attacks of acute intermittent porphyria in developing countries
Authors: PRABAHAR MURUGESAN R. , MANORAJAN RAJENDRAN , SATHIYAKUMAR DEVASAHAYAM , SOUNDARARAJAN PERIYASAMY , JAYAKUMAR MATCHA
Published: February 2008

Acute intermittent prophyria (AIP) is an autosomal dominant disease that results from a defect in the enzyme porphobilinogen deaminase. Acute intermittent porphyria is the most common of hepatic porphyrias and can tax the therapeutic capabilities of the physician to the limit. Motor weakness is a major feature of an acute attack, and flaccid paralysis of all extremities can occur rapidly, within a matter of days. The acute attacks may be life threatening. Hematin (Heme Arginate) should be given early during an acute attack to prevent neurologic sequel. Hemodialysis and hemoperfusion have been tried in the treatment of acute attacks of AIP with success. As hematin is not available in India, a severe acute attack of AIP in a patient was managed with hemodialysis successfully. Later, hematin was imported and provided to the patient. An 18‐year‐old girl was admitted to our hospital with recurrent abdominal pain and 2 episodes of convulsions. She had undergone an appendectomy earlier at another hospital for abdominal pain. On evaluation, she had hyponatremia, episodic abnormal behavior, generalized muscle pain, hypertension, and sinus tachycardia. In view of the above clinical picture, a clinical diagnosis of acute intermittent porphyria was made. Her 24‐hr urinary porphobilinogen was 90.8 mg/day (<2 mg—normal) and α amino levalunic acid was 108.8 mg/day (1–7 mg—normal), consistent with the diagnosis. Her hyponatremia was corrected. Arrangements were made to import hematin and she was managed with dextrose infusion. Meanwhile, she developed flaccid quardriparesis with urinary incontinence and bulbar palsy. Her brain MRI was normal. Her nerve conduction study was suggestive of motor radiculoneuropathy. Specific treatment for severe porphyric crisis was planned. She failed to improve with dextrose infusion alone. As hematin was not readily available in the country, other therapeutic options were considered. As few case reports of AIP being successfully treated with hemodialysis were available, the option of dialytic support was explained to the family. After procuring informed consent, she was subjected to hemodialysis for 4 hr in the first day, increasing to 6 hr a day for the next 6 days. Her abdominal pain and myalgia subsided on the third day of dialysis. Her lower limb muscle power improved and she became ambulant by the fourth day. Urinary retention improved within 4 days. Hematin was imported by then from the United States. Later, 2 doses of hematin (4 mg/kg–160 mg in 20% albumin) were given via a central vein. She was maintained on physiotherapy. Repeat nerve conduction study revealed recovery. She has been provided with a list of drugs that have to be avoided. Currently, she is on outpatient follow‐up with occasional abdominal pain, which subsides with intravenous dextrose therapy.
Effect of acetate‐free biofiltration with a potassium‐profiled dialysate on the control of cardiac arrhythmias in patients at risk: A pilot study
Authors: MUÑOZ Rosa I. , MONTENEGRO Jesús , SALCEDO Alberto , GALLARDO Isabel , MARTÍNEZ Isabel , QUINTANILLA Nuria , SARACHO Ramón , LEKUONA Iñaki
Published: February 2008

Cardiac arrhythmias are a frequent event in chronic hemodialysis patients. The aim of this study was to evaluate the efficacy and safety of acetate‐free hemofiltration with potassium‐profiled dialysate (AFB‐K) dialysis compared with constant potassium acetate‐free biofiltration (AFB). Twelve patients (mean age 79 years) affected by cardiac arrhythmias or at a high risk for arrhythmia (advanced age, hypertension, left ventricular hypertrophy, heart valve disease, coronary artery disease, diabetes, paroxysmal atrial fibrillation) participated in a single‐center, sequential cohort study. All were treated with hemodialysis 3 times per week, using constant potassium AFB for the first 3 weeks, followed by an AFB‐K dialysate for the subsequent 3 weeks. The hemofilter, duration of dialysis, and electrolyte concentration were the same in both treatments. Both AFB‐K and constant potassium AFB dialytic techniques were safe and well tolerated. The results of biochemical tests were similar, except for serum potassium levels after 2 hr of dialysis, which were significantly higher in the AFB‐K group (4.0 mmol/L) than in the constant potassium AFB group (3.6 mmol/L) (p<0.001). All cardiac variables improved during AFB‐K dialysis. There was a significant reduction of postdialysis QT intervals corrected for heart rate in the AFB‐K group (448.8 ms) compared with the constant potassium AFB group (456.8 ms) (p=0.039). The severity and mean number of ventricular extasystoles also decreased (163.5 vs. 444.5/24 hr). Potassium profiling during hemodialysis treatment may be beneficial for patients with arrhythmias or at those risk of arrhythmias, particularly those with predialysis hyperkalemia.
An Evaluation of Vaporizing Rates of SiO2 and TiO2 As Protective Coatings for Ultrahigh Temperature Ceramic Composites
Authors: Bronson Arturo , Chessa Jack
Published: February 2008

For temperatures >1973 K, the thermodynamic and kinetic analyses of the major gaseous species for a liquid titanate layer would vaporize significantly less than a silicate layer, when considering these layers as a protective barrier for ultrahigh temperature ceramic composites. At 2500 K, the major species is TiO(g) with pTiO(g)=0.1 kPa compared with SiO(g) with pSiO(g)=1.3 × 103 kPa at the Ti/TiO2 and Si/SiO2 equilibrium, respectively. The SiO(g) attains a partial pressure greater than ambient pressure at 2500 K even with a thermodynamic activity of 0.01 considering equilibration with a silicide (e.g., TiSix). In addition, at 2500 K the TiO2 layer would vaporize at a rate of 0.23 mm/s compared with the SiO2 layer's loss rate of 207 mm/s. Although the oxygen diffusivity and permeability through titanate solutions must be further analyzed, the thermodynamic and kinetic analyses for vaporization indicate a longer duration for a liquid titanate than for a liquid silicate layer at ultrahigh temperatures.
Activation of TGF‐β within cultured hepatocytes and in liver injury leads to intracrine signaling with expression of connective tissue growth factor
Authors: Gressner Olav A. , Lahme Birgit , Siluschek Monika , Rehbein Katharina , Herrmann Jens , Weiskirchen Ralf , Gressner Axel M.
Published: February 2008

Recently, synthesis and secretion of connective tissue growth factor (CTGF)/CYR61/CTGF/NOV‐family member 2 (CCN2) in cultures of hepatocytes were shown, which are sensitively up‐regulated by exogenous TGF‐β. In this study TGF‐β‐dependent CTGF/CCN2 expression in hepatocytes cultured under completely TGF‐β‐free conditions was analysed by Western‐blots, metabolic labelling, and CTGF‐reporter gene assays. In alkaline phosphatase monoclonal anti‐alkaline phosphatase complex (APAAP)‐staining of cultured hepatocytes it was demonstrated that latent TGF‐β within the hepatocytes becomes rapidly detectable during culture indicating an intracellular demasking of the mature TGF‐β antigen. Subsequent signaling to theCTGF/CCN2 promoter occurs via p‐Smad2, whereas p‐Smad3 does not seem to be involved. Cycloheximide did not abolish the rapid immunocytochemical appearance of mature TGF‐β, but calpain inhibitors partially suppressed intracellular TGF‐β activation and subsequently CTGF up‐regulation. Calpain treatment had the reverse effect. None of the inhibitors of extracellular TGF‐β signalling was effective in the reduction of spontaneous CTGF synthesis, but intracellularly acting Alk 4‐/Alk 5‐specific inhibitor SB‐431542 was able to diminish CTGF expression. The assumption that latent intracellular TGF‐β is activated by calpains during culture‐induced stress or injurious conditions in the liver in vivo was further validated by a direct effect of calpains on the activation of recombinant latent TGF‐β. In conclusion, these data are the first to suggest the possibility of intracrine TGF‐β signalling due to calpain‐dependent intracellular proteolytic activation leading to transcriptional activation of CTGF/CCN2 as a TGF‐β‐sensitive reporter gene. This mechanism might be deleterious for keeping long‐term hepatocyte cultures due to TGF‐β‐induced apoptosis and, further, might be of relevance for induction of apoptosis or epithelial‐mesenchymal transition of hepatocytes in injured liver.
The Sarcoplasmic Reticulum: An Organized Patchwork of Specialized Domains
Authors: Rossi Daniela , Barone Virginia , Giacomello Emiliana , Cusimano Vincenza , Sorrentino Vincenzo
Published: February 2008

The sarcoplasmic reticulum (SR) of skeletal muscle cells is a convoluted structure composed of a variety of tubules and cisternae, which share a continuous lumen delimited by a single continuous membrane, branching to form a network that surrounds each myofibril. In this network, some specific domains basically represented by the longitudinal SR and the junctional SR can be distinguished. These domains are mainly dedicated to Ca2+ homeostasis in relation to regulation of muscle contraction, with the longitudinal SR representing the sites of Ca2+ uptake and storage and the junctional SR representing the sites of Ca2+ release. To perform its functions, the SR takes contact with other cellular elements, the sarcolemma, the contractile apparatus and the mitochondria, giving rise to a number of interactions, most of which are still to be defined at the molecular level. This review will describe some of the most recent advancements in understanding the organization of this complex network and its specific domains. Furthermore, we shall address initial evidence on how SR proteins are retained at distinct SR domains.
Rural veterinary services in Western Australia: Part A. Government veterinary services
Authors: Maxwell JAL , Costa ND , Layman LL , Robertson ID
Published: February 2008

Objective    To determine the status of rural veterinary services in Western Australia.

Procedure    Two questionnaires were mailed to eligible, registered veterinary surgeons in Western Australia in 2006. The first was mailed to government veterinarians and the second to private practitioners in rural practice. Part A presents the replies from government veterinary officers and Part B the replies from rural practitioners. Replies were transferred to Microsoft Excel for analysis.

Results    Sixty‐seven per cent of government veterinary officers responded to the questionnaire. Eighty per cent of these had been in the service for 20 years or more and their average age was 54. Work with sheep and beef cattle occupied 75% of their time, with dairy cattle receiving 10% and pigs and poultry less than 10%. The majority of respondents reported changes in the attitude of farmers to the service as a result of rural recessions and the decision to make a direct charge for government veterinary services. Although most respondents thought that the government veterinary service would continue in the future there were differences of opinion as to what form that would take.

Conclusion    Government veterinary services in Western Australia are undergoing major changes, with the service decreasing in size and scope. Recently the Department of Agriculture has been renamed the Department of Agriculture and Food and it is likely that the role of its veterinary officers will change accordingly.
SURFACE POTENTIAL AND PHOTO‐ADSORPTION ONTO SEMICONDUCTORS
Authors: Levine Sumner N.
Published: February 2008

Abstract— A theory of photo‐adsorption onto semiconductors is developed using the kinetic expressions and the relations for steady state carrier concentrations in terms of the quasien Fermi levels. Expressions are derived which emphasize the importance of the surface potential. In particular it is shown that a significant quantity is the ratio of the surface potential to a critical quantity, Ysc. An expression for the latter is given and it is shown that photoadsorption occurs if the ratio is greater than unity while desorption occurs if the ratio is less than unity. The theory also suggests a useful graphical representation of the effects of impurities and surface potential on adsorption.
PHOTOCHEMISTRY OF THYMINE IN AQUEOUS SOLUTION*
Authors: Alcántara Raúl , Wang Shih Yi
Published: February 2008

Abstract— Uracil, 5‐hydroxymethyluracil, and 5‐formyluracil have been identified by paper chromatography as the photo‐oxidation products from an aqueous solution of thymine which was irradiated with germicidal lamps. These findings are parallel to the photochemical changes of 1,3‐dimethylthyniine as reported in the preceding paper.
QUENCHING OF THE TRIPLET STATE OF CHLOROPHYLL a BY ASCORBIC ACID AND ASCORBATE IN ETHANOLIC SOLUTION
Authors: Holmes DeField T.
Published: February 2008

Abstract— Ascorbic acid and ascorbate in chlorophyll ethanol solution were found to be fairly efficient quenchers of the chlorophyll triplet state; comparable to the efficiency of ascorbic acid as a quencher in aqueous pyridine solution.

It has been well established that ascorbic acid quenches the triplet state of chlorophyll in aqueous pyridine solution.(1,2) The bimolecular quenching constant, kQ, is very much less than that for O2 or quinine.(3,4)

Information regarding the quenching of the triplet state of chlorophyll by ascorbic acid in ethanolic solution is lacking. There has been some question as to whether ascorbic acid reduces photoexcited chloro‐phyll‐ethanolic solution because of its high oxidation potential, or because like the ascorbate ion, it acts only as a quencher; both ascorbic acid and ascorbate in high concentrations gave low quantum yields.(5) The quenching of the triplet state by ascorbic acid and ascorbate was determined by the flash‐photolytic method.
Water sources and carbon isotope composition (δ13C) of selected tree species of the Italian Alps
Authors: Valentini R. , Anfodillo T. , Ehleringer J.R.
Published: February 2008

Selected species of the Italian Alpine region (Piceaabies (L.) Karst., Pinussylvestris L., Pinuscembra L., and Larixdecidua L.) have been investigated in terms of water-source utilization and carbon fixation estimated by the analysis of hydrogen and carbon stable isotopes composition at two sites of differing altitude (1000 and 1500 m above sea level). Larixdecidua is the species most dependent on groundwater in both sites, while Pinussylvestris utilizes rainwater to a greater extent. Concurrently, Pinussylvestris displayed the highest value of the carbon isotopic ratio (δ13C = −25.9 ± 0.6‰), while Larixdecidua had the most negative one (δ13C = −29.0 ± 0.4‰). A relationship was found between water-source utilization and carbon-isotope discrimination.
Adaptive variation in Piceamariana from northwestern Ontario determined by short-term common environment tests
Authors: Parker William H. , Niejenhuis Annette Van , Charrette Paul
Published: February 2008

To obtain a better understanding of the pattern of adaptive variation of Piceamariana (Mill.) B.S.P. from northwestern Ontario, a short-term provenance test was carried out for 75 seed sources collected east and west of Lake Nipigon. Provenances were grown in common environments at a greenhouse for two seasons (1990–1991) and a farm field and a forestry trial each for four growing seasons (1990–1993). Twenty-five growth and phenological variables were determined, including seedling height, needle flushing date, and the timing of shoot elongation. Significant levels of interprovenance variation were present for 18 of these variables. Graphic analysis of the pattern of variation indicated that sources from the southwestern portion of the collected area generally grew faster and flushed later than easterly sources near the north shore of Lake Superior. Superimposed on this general pattern were several irregularities caused by one or more provenances. Multiple regressions were run for each of the 18 variables against latitude, elevation, and 12 climatic variables interpolated for each of the seed sources by a geographic information system from 1951–1980 data obtained from 56 nearby weather stations. Large coefficients of variation (up to 0.57) were obtained for some variables. Combinations of climatic variables, including winter minimum and summer maximum temperatures together with precipitation and timing of the growing season, were excellent predictors of black spruce needle flushing dates, while summer temperature, precipitation, and elevation were moderately good predictors of height growth.
Population-dependent selection strategies needed for 2-year-old black cottonwood clones
Authors: Riemenschneider Don E. , McMahon Bernard G. , Ostry Michael E.
Published: February 2008

We conducted a study to determine whether genotypic and phenotypic covariances among important traits differed between collections of black cottonwood (Populustrichocarpa Torn & Gray) from British Columbia and northern Idaho. We also determined how differences in estimated covariances could affect various multiple-trait clonal selection strategies. The experimental design consisted of 166 clones from British Columbia and northern Idaho intermixed at random in two replications of three-tree row plots. Measurements made during the second growing season included tree height, frequency and number of sylleptic branches, number of leaves, and the lengths and areas of leaf plastochron index 5, 10, and 15 leaves at the end of the growing season. The severity and extent of Melampsora leaf rust and Septoria leaf spot were also evaluated. We found high heritability for tree height, phenology, leaf morphology, and resistance to damaging agents. However, no advantage to using leaf morphology to improve genetic selection for tree height was demonstrable. Restricted selection indices had high potential utility for controlling increases in damaging agents. However, the relation between tree height and leaf diseases varied between the British Columbia and northern Idaho collections of black cottonwood, and between black cottonwood and an adjacent experimental population of balsam poplar (Populusbalsamifera L.). Such population-related variation in intertrait covariances suggests that selection strategies involving disease resistance may need to be evaluated on an individual population basis.
Transient β-glucuronidase expression in Scots pine tissues derived from mature trees
Authors: Aronen Tuija , Häggman Hely , Hohtola Anja
Published: February 2008

Vegetative buds and bud-derived calli and suspension cells from 5- to 50-year-old Scots pines (Pinussylvestris L.) were used as targets for biolistic transformation. The gene construct used in the experiments was 35S CaMV–β-glucuronidase (GUS). The highest average level of transient GUS expression was found in suspension cells: 1229 ± 359 (mean ± SE) expressing cells per million. Transient expression was found in 35 of 44 (79%) tree genotypes studied. The expression level in buds and in calli was low: one or two spots per expressing bud. Growth-regulator pretreatment (BAP and 2,4-D) increased the number of GUS-expressing buds significantly. The high transient expression level in suspensions and the high percentage of GUS-expressing genotypes suggest that mature Scots pine tissues have potential for further transformation and genetic regulation studies.
An economic assessment of a nest-box strategy for the conservation of an endangered species
Authors: McKenney Daniel W. , Lindenmayer David B.
Published: February 2008

There is increasing concern over the extinction of plants and animals resulting from modern land-use activities. Many jurisdictions have enacted legislation that limits these activities and directs resource managers to take mitigative steps. In this paper we demonstrate how standard economic analysis can be used to assess the costs of alternative conservation management strategies. The costs of a nest box program for the conservation of an endangered Australian arboreal marsupial, Leadbeater's possum (Gymnobelideusleadbeateri McCoy), are compared with the timber production value of the forests they inhabit. Nest boxes have been suggested as a mechanism to maintain the species and still allow timber harvesting to occur. In most scenarios nest boxes cost more than logging bans even under a variety of discount rates. Thus, given an exogenous policy decision to conserve Leadbeater's possum, the most efficient management strategy in this case is to not harvest the old-growth forests that are likely to support the species.
Prediction of poplar leaf rust epidemics from a leaf-disk assay
Authors: Hamelin Richard C. , Ferriss Richard S. , Shain Louis , Thielges Bart A.
Published: February 2008

The reliability of a leaf-disk assay to assess resistance of Populusdeltoides Bartr. to Melampsoramedusae Thuëm. f.sp. deltoidae, the causal agent of poplar leaf rust, was evaluated. Leaf disks of eight host genotypes were inoculated in a spore settling tower with 11 isolates of the pathogen in all possible combinations, and the latent period, infection probability, sporulation, and progeny/parent ratio were recorded. Correlations were established between these measures and measures derived from field epidemics, namely the relative area under the disease progress curve, the apparent rate of infection, the final disease severity, and the number of days before defoliation. Four genotypes were highly resistant to all 11 isolates tested with the leaf-disk assay and to the local inoculum in field tests. Three genotypes were highly susceptible in inoculation assays and were also susceptible in the field. One genotype was highly resistant in inoculation assays but had intermediate resistance in the field. Significant correlations (p < 0.05) were found between all leaf-disk and all field parameters.
Representational Power of Restricted Boltzmann Machines and Deep Belief Networks
Authors: Le Roux Nicolas , Bengio Yoshua
Published: February 2008

Deep belief networks (DBN) are generative neural network models with many layers of hidden explanatory factors, recently introduced by Hinton, Osindero, and Teh (2006) along with a greedy layer-wise unsupervised learning algorithm. The building block of a DBN is a probabilistic model called a restricted Boltzmann machine (RBM), used to represent one layer of the model. Restricted Boltzmann machines are interesting because inference is easy in them and because they have been successfully used as building blocks for training deeper models. We first prove that adding hidden units yields strictly improved modeling power, while a second theorem shows that RBMs are universal approximators of discrete distributions. We then study the question of whether DBNs with more layers are strictly more powerful in terms of representational power. This suggests a new and less greedy criterion for training RBMs within DBNs.
Influence of "Flexible" versus "Rigid" Nanoparticles on the Stability of Matrix Metalloproteinase-7
Authors: Ganguly Bratati , Srivastava D. K.
Published: February 2008

Matrix Metalloproteinase-7 (MMP-7) is invariably expressed in a variety of cancer cells, and exhibits the potentials to interact with differently charged macromolecular surfaces. To ascertain whether the nature of the charge carrying surfaces influences the stability as well as catalytic
properties of the enzyme, we compared the effects of differently charged lipid (representative of "flexible") and gold ("rigid") nanoparticles. The experimental data revealed that the catalytic activity of MMP-7 is impaired only by the positively charged lipid nanoparticles, and it remains
unaffected by their negatively charged or neutral counterparts. On the other hand, both positively and negatively charged gold nanoparticles impair the enzyme activity with nearly equal potency; no significant influence of neutral gold nanoparticles was noted on the enzyme activity. Unlike
lipid nanoparticles, the charged gold nanoparticles mediated effects were found to be manifested partially via the inactivation of the enzyme. Arguments are presented that both the "rigidity" as well as the surface curvature of the lipid ("flexible") vis a vis the gold ("rigid") nanoparticles
are responsible for eliciting differential influence on the catalytic activity as well as the stability of MMP-7.
Quantification of PRL/Stat5 signaling with a novel pGL4-CISH reporter
Authors: Fang Feng , Antico Giovanni , Zheng Jiamao , Clevenger Charles V
Published: February 2008

Background

Elevations of serum prolactin (PRL) are associated with an increased risk for breast cancer. PRL signaling through its prolactin receptor (PRLr) involves the Jak2/Stat5 pathway. Luciferase-based reporter assays have been widely used to evaluate the activity of this pathway. However, the existing reporters are often not sensitive enough to monitor the effect of PRL in this pathway.

Results

In this study, a new biologically relevant reporter, pGL4-CISH, was generated to study the PRL/Jak2/Stat5 signaling pathway. The sensitivity of pGL4-CISH to detect PRL was superior to that of several other commonly utilized Stat5-responsive reporters. Interestingly, the enhanced function pGL4-CISH was restricted to the estrogen receptor positive (ER+) human breast cancer cell lines T47D and MCF7, but not in the ER-MDA-231, BT-474, or MCF10A cell lines. Overexpression of Stat5 further enhanced the effect of PRL on pGL4-CISH.

Conclusion

These studies demonstrate that pGL4-CISH is a novel and sensitive reporter for assessing the activity of the PRL/Stat5 signaling pathway in the ER+ human breast cancer cells.
Xenopus NEDD1 is required for microtubule organization in Xenopus egg extracts
Authors: Liu Lingling , Wiese Christiane
Published: February 2008

The centrosome serves as the major microtubule-nucleating and -organizing center in animal cells. It is composed of hundreds of proteins. The molecular details of how centrosomal proteins contribute to centrotome function are only beginning to emerge. Members of the neuron-precursor-cell-expressed developmentally downregulated protein 1 (NEDD1) family of conserved proteins have recently been implicated in recruiting γ-tubulin and its associated proteins, which together make up the γ-tubulin ring complex (γTuRC), to the centrosome. Human NEDD1 and its Drosophila ortholog Dgp71WD are WD-repeat proteins that interact with the γTuRC. Experimental knockdown of human NEDD1 was recently shown to result in loss of γ-tubulin from the centrosome. By contrast, however, Dgp71WD knockdown has no effect on targeting the γTuRC to the centrosome in flies. Using Xenopus egg extracts, we show that Xenopus NEDD1 is mostly dispensable for targeting γ-tubulin to centrosomes, but that microtubule organization is disrupted in NEDD1-depleted extracts. We show that NEDD1 exists in a complex that is distinct from the γTuRC, suggesting that NEDD1 may not be a bona fide subunit of the Xenopus γTuRC. We propose that the main function of NEDD1 in Xenopus is in microtubule organization.
The AP3 adaptor is involved in the transport of membrane proteins to acidocalcisomes of Leishmania
Authors: Besteiro Sébastien , Tonn Daniela , Tetley Laurence , Coombs Graham H. , Mottram Jeremy C.
Published: February 2008

Lysosomal function is crucial for the differentiation and infectivity of the parasitic protozoon Leishmania major. To study lysosomal biogenesis, an L. major mutant deficient in the δ subunit of the adaptor protein 3 (AP3 δ) complex was generated. Structure and proteolytic capacity of the lysosomal compartment were apparently unaffected in the AP3-deficient mutant; however, defects were identified in its acidocalcisomes. These are acidic organelles enriched in calcium and phosphorus, conserved from bacteria to eukaryotes, whose function remains enigmatic. The acidocalcisomes of the L. major mutant lacked membrane-bound proton pumps (notably V-H+-PPase), were less acidic than normal acidocalcisomes and devoid of polyphosphate, but contained a soluble pyrophosphatase. The mutant parasites were viable in vitro, but were unable to establish an infection in mice, which indicates a role for AP3 in determining – possibly through an acidocalcisome-related function – the virulence of the parasite. AP3 transport function has been linked previously to lysosome-related organelles such as platelet dense granules, which appear to share several features with acidocalcisomes. Our findings, implicating that AP3 has a role in transport to acidocalcisomes, thus provide further evidence that biogenesis of acidocalcisomes resembles that of lysosome-related organelles, and that both may have conserved origins.
Proapoptotic BH3-Only Protein Bid Is Essential For Death Receptor–Induced Apoptosis of Pancreatic β-Cells
Authors: McKenzie Mark D. , Carrington Emma M. , Kaufmann Thomas , Strasser Andreas , Huang David C.S. , Kay Thomas W.H. , Allison Janette , Thomas Helen E.
Published: February 2008

OBJECTIVE—Apoptosis of pancreatic β-cells is critical in both diabetes development and failure of islet transplantation. The role in these processes of pro- and antiapoptotic Bcl-2 family proteins, which regulate apoptosis by controlling mitochondrial integrity, remains poorly understood. We investigated the role of the BH3-only protein Bid and the multi-BH domain proapoptotic Bax and Bak, as well as prosurvival Bcl-2, in β-cell apoptosis.

RESEARCH DESIGN AND METHODS—We isolated islets from mice lacking Bid, Bax, or Bak and those overexpressing Bcl-2 and exposed them to Fas ligand, tumor necrosis factor (TNF)-α, and proinflammatory cytokines or cytotoxic stimuli that activate the mitochondrial apoptotic pathway (staurosporine, etoposide, γ-radiation, tunicamycin, and thapsigargin). Nuclear fragmentation was measured by flow cytometry.

RESULTS—Development and function of islets were not affected by loss of Bid, and Bid-deficient islets were as susceptible as wild-type islets to cytotoxic stimuli that cause apoptosis via the mitochondrial pathway. In contrast, Bid-deficient islets and those overexpressing antiapoptotic Bcl-2 were protected from Fas ligand–induced apoptosis. Bid-deficient islets were also resistant to apoptosis induced by TNF-α plus cycloheximide and were partially resistant to proinflammatory cytokine-induced death. Loss of the multi-BH domain proapoptotic Bax or Bak protected islets partially from death receptor–induced apoptosis.

CONCLUSIONS—These results demonstrate that Bid is essential for death receptor–induced apoptosis of islets, similar to its demonstrated role in hepatocytes. This indicates that blocking Bid activity may be useful for protection of islets from immune-mediated attack and possibly also in other pathological states in which β-cells are destroyed.