bluuebunny/crossref_metadata_2025 huggingface dataset:
Disparate cholinergic currents in rat principal trigeminal sensory nucleus neurons mediated by M1 and M2 receptors: a possible mechanism for selective gating of afferent sensory neurotransmission
Authors: Kohlmeier Kristi A. , Soja Peter J. , Kristensen Morten P.
Published: June 2006

Neurons situated in the principal sensory trigeminal nucleus (PSTN) convey orofacial sensory inputs to thalamic relay regions and higher brain centres, and the excitability of these ascending tract cells is modulated across sleep/wakefulness states and during pain conditions. Moreover, acetylcholine release changes profoundly across sleep/wakefulness states and ascending sensory neurotransmission is altered by cholinergic agonists. An intriguing possibility is, therefore, that cholinergic mechanisms mediate such state‐dependent modulation of PSTN tract neurons. We tested the hypotheses that cholinergic agonists can modulate PSTN cell excitability and that such effects are mediated by muscarinic receptor subtypes, using patch‐clamp methods in rat and mouse. In all examined cells, carbachol elicited an electrophysiological response that was independent of action potential generation as it persisted in the presence of tetrodotoxin. Responses were of three types: depolarization, hyperpolarization or a biphasic response consisting of hyperpolarization followed by depolarization. In voltage‐clamp mode, carbachol evoked corresponding inward, outward or biphasic currents. Moreover, immunostaining for the vesicle‐associated choline transporter showed cholinergic innervation of the PSTN. Using muscarinic receptor antagonists, we found that carbachol‐elicited PSTN neuron hyperpolarization was mediated by M2 receptors and depolarization, in large part, by M1 receptors. These data suggest that acetylcholine acting on M1 and M2 receptors may contribute to selective excitability enhancement or depression in individual, rostrally projecting sensory neurons. Such selective gating effects via cholinergic input may play a functional role in modulation of ascending sensory transmission, including across behavioral states typified by distinct cholinergic tone, e.g. sleep/wakefulness arousal levels or neuropathic pain conditions.
Mental health in women experiencing intimate partner violence as the efficiency goal of social welfare functions
Authors: von Eye Alexander , Anne Bogat G.
Published: June 2006

In this article, we propose that psychological goal functions, such as mental health, as well as income are important elements of social welfare. We examine the relationship between income, depression, social welfare (food stamps and Medicaid) and intimate partner violence, using a person‐orientation in a sample from the United States. Data from four time points of a longitudinal study of intimate partner violence are analysed. Clusters of women are derived based on whether or not they received or did not receive food stamps and Medicaid at each of the four time periods. These clusters differ on income and intimate partner violence as well as the trajectory of depression. However, a series of linear models suggests that only intimate partner violence (not income and social welfare variables) predict the development and level of depression over time. The effects of the social welfare variables we examined seem to be domain specific and do not influence the mental health of women receiving these services.
The progress of social development in South Africa
Authors: Gray Mel
Published: June 2006

In 1998, James Midgley issued a challenge for scholars to provide a systematic description and examination of the South African experience in implementing social development. This article attempts to meet this challenge by examining the progress of developmental welfare or social development in the first ten years of South Africa's transition to democracy under African National Congress (ANC) rule. In this article it is argued that because social development marries social and economic goals, one cannot evaluate developmental welfare or social development without examining shifts in economic policy. Thus, it also examines economic policy transitions from development, to growth, to black economic empowerment. It shows how social security has become the major poverty alleviation measure within the developmental welfare system. It acknowledges that it is tough for developmental welfare to succeed in an economic system that promotes gross income disparities and a widening gap between rich and poor. Social development needs widespread institutional support to succeed and this is unlikely to be forthcoming while there is high unemployment, low economic growth and insufficient foreign investment. However, this state of affairs is unlikely to change as long as the government intervenes in the economy, promotes black economic empowerment and centralises decision‐making.
Surface to subsurface freshwater connections: phylogeographic and habitat analyses of Cambarus tenebrosus, a facultative cave‐dwelling crayfish
Authors: Finlay J. B. , Buhay J. E. , Crandall K. A.
Published: June 2006

This study examined the phylogeography and population demographics of Cambarus tenebrosus, which has an unusually large distribution for a freshwater crayfish species, encompassing the Interior Lowlands and Cumberland Plateau of the eastern United States. This facultative cave‐dweller provides a unique perspective on the biologic connections between surface and subsurface freshwater ecosystems, which are considered to be highly imperiled due to pollution and habitat degradation. The 16S mitochondrial gene was sequenced for 233 individuals from 84 cave and 20 surface locations throughout the range, with most sampling concentrated around the Cumberland Plateau of the southern Appalachians, to assess conservation status of this species and examine the extent of gene flow between the two habitat types. Cave and surface populations formed a single monophyletic group relative to Cambarus striatus, and clades showed strong geographical associations, but lacked habitat structuring. Occupation of subterranean environments does not appear to be a recent event in the evolutionary history of the species. The large amount of genetic diversity within the species, coupled with its ability to inhabit surface and subsurface environments, suggests that this species may pose a threat as a possible invasive species in other karst‐dominated landscapes.
Divided we fail: the importance of social integration for the re‐introduction of endangered African wild dogs (Lycaon pictus)
Authors: Gusset M. , Slotow R. , Somers M. J.
Published: June 2006

In South Africa, a plan was launched to manage separate sub‐populations of endangered African wild dogs Lycaon pictus in several small, geographically isolated conservation areas as a single meta‐population. This intensive management approach involves the re‐introduction of wild dogs into suitable conservation areas and periodic translocations among them. Here, we sought to evaluate the relevance of taking the formation of new reproductive units into consideration in promoting such translocation attempts. For this purpose, we analysed the behavioural process of integrating translocated wild dogs into new packs in pre‐release holding facilities in Hluhluwe‐iMfolozi Park, one of the meta‐population conservation areas. In addition, we reviewed findings from other wild dog translocation attempts in regard to the outcome of using variously composed groups and captive‐bred animals for the artificial creation of new packs for translocation purposes. We show the importance of social integration before release for wild dog re‐introductions and translocations to be successful. We also present a set of proximate factors, including management manipulation of social relationships, which promote pack formation in pre‐release holding facilities. This demonstrably enhances the efficiency of costly wild dog re‐introductions and translocations, thereby illustrating the implications of sociality for endangered species recovery.
Romantic Scotland, tragic England, ambiguous Britain: constructions of ‘the Empire’ in post‐devolution national accounting
Authors: CONDOR SUSAN , ABELL JACKIE
Published: June 2006

ABSTRACT. This article compares the ways in which references to ‘the (British) Empire’ were constructed and used in interview accounts of national identity and domestic politics in Scotland and in England. In Scotland, spontaneous accounts of Empire were typically formulated in conjunction with nationalist moral meta‐narratives. Respondents variously inferred heroic national character from Scotland's role in Empire, or cast Scottish history as an enduring struggle between progressive forces of nationalism and atavistic forces of Anglo‐British colonialism. The construct of Britishness was often seen to derive from, and to be synonymous with, the history of Empire. In England, the Empire story tended to be framed within anti‐nationalist meta‐narratives. Imperialism was generally understood to represent a product of excessive nationalism, and tales of Empire were used to draw exemplary moral lessons concerning the deficiencies of Anglo‐British national character and of the catastrophic consequences of the pursuit of national self‐interest more generally. The existence of Britain, and the construct of Britishness, were generally understood to both predate and postdate the history of Empire.
Prion protein reduces both oxidative and non‐oxidative copper toxicity
Authors: Haigh Cathryn L. , Brown David R.
Published: June 2006

The prion protein is a membrane tethered glycoprotein that binds copper. Conversion to an abnormal isoform is associated with neurodegenerative diseases known as prion diseases. Expression of the prion protein has been suggested to prevent cell death caused by oxidative stress. Using cell based models we investigated the potential of the prion protein to protect against copper toxicity. Although prion protein expression effectively protected neurones from copper toxicity, this protection was not necessarily associated with reduction in oxidative damage. We also showed that glycine and the prion protein could both protect neuronal cells from oxidative stress. Only the prion protein could protect these cells from the toxicity of copper. In contrast glycine increased copper toxicity without any apparent oxidative stress or lipid peroxidation. Mutational analysis showed that protection by the prion protein was dependent upon the copper binding octameric repeat region. Our findings demonstrate that copper toxicity can be independent of measured oxidative stress and that prion protein expression primarily protects against copper toxicity independently of the mechanism of cell death.
Glycine receptors: recent insights into their structural organization and functional diversity
Authors: Betz Heinrich , Laube Bodo
Published: June 2006

Strychnine‐sensitive glycine receptors (GlyRs) are known to mediate synaptic inhibition in spinal cord, brainstem and other regions of the CNS. During the past 5 years, considerable progress has been made in delineating structural determinants of ligand binding and channel activation in recombinant GlyRs. Furthermore, immunohistochemical and gene inactivation studies have disclosed distinct distributions and functions of differentially expressed GlyR subtypes in retina, hippocampus and the dorsal horn of the spinal cord. Accordingly, GlyRs regulate not only the excitability of motor and sensory neurones, but are also essential for the processing of photoreceptor signals, neuronal development and inflammatory pain sensitization. Hence, these receptors constitute promising targets for the development of clinically useful compounds.
Defective axonal transport of neurofilament proteins in neurons overexpressing peripherin
Authors: Millecamps Stéphanie , Robertson Janice , Lariviere Roxanne , Mallet Jacques , Julien Jean‐Pierre
Published: June 2006

Peripherin is a type III neuronal intermediate filament detected in motor neuron inclusions of amyotrophic lateral sclerosis (ALS) patients. We previously reported that overexpression of peripherin provokes late‐onset motor neuron dysfunction in transgenic mice. Here, we show that peripherin overexpression slows down axonal transport of neurofilament (NF) proteins, and that the transport defect precedes by several months the appearance of axonal spheroids in adult mice. Defective NF transport by peripherin up‐regulation was further confirmed with dorsal root ganglia (DRG) neurons cultured from peripherin transgenic embryos. Immunofluorescence microscopy and western blotting revealed that excess peripherin provokes reduction in levels of hyperphosphorylated NF‐H species in DRG neurites. Similarly the transport of a green fluorescent protein (GFP)‐tagged NF‐M, delivered by means of a lentiviral construct, was impaired in DRG neurites overexpressing peripherin. These results demonstrate that peripherin overexpression can cause defective transport of type IV NF proteins, a phenomenon that may account for the progressive formation of ALS‐like spheroids in axons.
Antagonism by imidazoline – type drugs of muscarinic and other receptors in the guinea‐pig ileum
Authors: Salazar‐Bookaman M. M. , Miller D. D. , Patil P. N.
Published: June 2006

1 Several imidazolines were examined for the antagonism of muscarinic (M3) and other receptors on the isolated ileum of guinea‐pig. The effect of the muscarinic agonist, carbachol was competitively antagonized by oxymetazoline at 10−5 m. A dissociation constant (KB) of 3.6 μmfor the antagonist was calculated. At higher concentrations, 3 × 10−5and 10−4 m, of the antagonist, the agonist dose–response curve was shifted to the right with a decrease in the maximum effect. Thus, a non‐competitive block occurred at higher concentrations of oxymetazoline. Blockade of histamine H, and serotonin receptor‐mediated responses by oxymetazoline were also of a non‐competitive type.

2 Naphazoline at 10−4 mshifted the dose‐response curves of carbachol and serotonin to the right by two‐ and 15‐fold, respectively. The maximum contraction of the agonist was not affected. Tolazoline also had a weak antihistaminic activity. At similar concentration; tetrahydrozoline clonidine and phentolamine at 10−5 mproduced two‐, three‐ and four‐fold shift of the carbachol dose–response curve without significant changes in the maxima. Neither methoxamine, p‐amino‐clonidine nor cimetidine blocked the responses of carbachol.

3 The isosteric nature of theα‐adrenoceptor agonist, oxymetazoline and some imidazolines with carbachol, in part, explains its molecular competition at the muscarinic M3receptor of the guinea‐pig ileum. Surprisingly, contractile effects of carbachol (M3), histamine (H1) or serotonin (5HT3/5HT4) were not influenced by methoxamine, tetrahydrozoline, p‐amino clonidine and cimetidine.
Muscarinic receptor subtypes in neuronal and non‐neuronal cholinergic function
Authors: Eglen R. M.
Published: June 2006

1 Muscarinic M1–M5receptors mediate the metabotropic actions of acetylcholine in the nervous system. A growing body of data indicate they also mediate autocrine functions of the molecule. The availability of novel and selective muscarinic agonists and antagonists, as well asin vivogene disruption techniques, has clarified the roles of muscarinic receptors in mediating both functions of acetylcholine.

2 Selective M1agonists or mixed M1agonists/M2antagonists may provide an approach to the treatment of cognitive disorders, while M3antagonism, or mixed M2/M3antagonists, are approved for the treatment of contractility disorders including overactive bladder and chronic obstructive pulmonary disease. Preclinical data suggest that selective agonism of the M4receptor will provide novel anti‐nociceptive agents, while therapeutics‐based upon agonism or antagonism of the muscarinic M5receptor have yet to be reported.

3 The autocrine functions of muscarinic receptors broadly fall into two areas – control of cell growth or proliferation and mediation of the release of chemical mediators from epithelial cells, ultimately causing muscle relaxation. The former particularly are involved in embryological development, oncogenesis, keratinocyte function and immune responsiveness. The latter regulate contractility of smooth muscle in the vasculature, airways and urinary bladder.

4 Most attention has focused on muscarinic M1or M3receptors which mediate lymphocyte immunoresponsiveness, cell migration and release of smooth muscle relaxant factors. Muscarinic M4receptors are implicated in the regulation of keratinocyte adhesion and M2receptors in stem cell proliferation and development. Little data are available concerning the M5receptor, partly due to the difficulties in defining the subtype pharmacologically.

5 The autocrine functions of acetylcholine, like those in the nervous system, involve activation of several muscarinic receptor subtypes. Consequently, the role of these subtypes in autocrine, as well neuronal cholinergic systems, significantly expands their importance in physiology and pathophysiology.
Regulation of bladder muscarinic receptor subtypes by experimental pathologies
Authors: Ruggieri M. R. , Braverman A. S.
Published: June 2006

1 The M3muscarinic receptor subtype is widely accepted as the receptor on smooth muscle cells that mediates cholinergic contraction of the normal urinary bladder and other smooth muscle tissues, however, we have found that the M2receptor participates in contraction under certain abnormal conditions. The aim of this study was to determine the effects of various experimental pathologies on the muscarinic receptor subtype mediating urinary bladder contraction.

2 Experimental pathologies resulting in bladder hypertrophy (denervation and outlet obstruction) result in an up‐regulation of bladder M2receptors and a change in the receptor subtype mediating contraction from M3towards M2. Preventing the denervation‐induced bladder hypertrophy by urinary diversion prevents this shift in contractile phenotype indicating that hypertrophy is responsible as opposed to denervationper se.

3 The hypertrophy‐induced increase in M2receptor density and contractile response is accompanied by an increase in the tissue concentrations of mRNA coding for the M2receptor subtype, however, M3receptor protein density does not correlate with changes in M3receptor tissue mRNA concentrations across different experimental pathologies.

4 This shift in contractile phenotype from M3towards M2subtype is also observed in aged male Sprague–Dawley rats but not females or either sex of the Fisher344 strain of rats.

5 Four repeated, sequential agonist concentration response curves also cause this shift in contractile phenotype in normal rat bladder stripsin vitro, as evidenced by a decrease in the affinity of the M3selective antagonistp‐fluoro‐hexahydro‐sila‐diphenidol (p‐F‐HHSiD).

6 A similar decrease in the contractile affinity of M3selective antagonists (darifenacin andp‐F‐HHSiD) is also observed in bladder specimens from patients with neurogenic bladder as well as certain organ transplant donors.

7 It is concluded that although the M3receptor subtype predominately mediates contraction under normal circumstances, the M2receptor subtype can take over a contractile role when the M3subtype becomes inactivated by, for example, repeated agonist exposures or bladder hypertrophy. This finding has substantial implications for the clinical treatment of abnormal bladder contractions.
The Effect of Two Publicly Funded Insurance Programs on Use of Dental Services for Young Children
Authors: Brickhouse Tegwyn H. , Rozier R. Gary , Slade Gary D.
Published: June 2006

Objective. The purpose of this study is to compare the use of dental services for preschool aged children enrolled in North Carolina Medicaid, a traditional program based on a fee‐for‐service schedule, and North Carolina Health Choice (NCHC), an State Children's Health Insurance Program (S‐CHIP) dental insurance program structured similarly to private insurance.

Study Population. All children (165,858) 1–5 years of age enrolled in Medicaid and S‐CHIP (NCHC) at some time during one study year (October 1, 1999–September 30, 2000).

Data Sources/Extraction Methods. Medicaid and NCHC enrollment and dental claims files were obtained for individual children.

Study Design. An observational study with a retrospective cohort design. Use of dental services for each child was measured as having at least one dental claim during the outcome period (October 1, 1999–September 30, 2000). Multivariable logistic regression models were developed to compare the effect of two differently administered insurance programs on the use of dental services, controlling for demographic, enrollment, and county characteristics.

Principle Findings. Children enrolled solely in S‐CHIP (NCHC) were 1.6 times more likely (95 percent confidence intervals (CI)=1.50–1.79) to have a dental visit than those enrolled solely in Medicaid. Prediction models for children enrolled for 12 months indicated that those enrolled in S‐CHIP (NCHC) had a significantly higher probability of having a dental visit (50 percent) than those enrolled in both plans (44 percent) or Medicaid only (39 percent), a trend found in all age groups.

Conclusions. The S‐CHIP (NCHC) program appears to provide children with increased access to dental care compared to children in the Medicaid program.
Learning from Doing Participatory Rural Research: Lessons from the Peak District National Park
Authors: Dougill A. J. , Fraser E. D. G. , Holden J. , Hubacek K. , Prell C. , Reed M. S. , Stagl S. , Stringer L. C.
Published: June 2006

Understanding the socio‐economic and environmental implications of rural change requires the active participation of many research disciplines and stakeholders. However, it remains unclear how to best integrate participatory and biophysical research to provide information useful to land managers and policy makers. This paper presents findings of a RELU scoping study that has formulated and applied a research framework based on stakeholder participation and adaptive learning to model rural change in the Peak District National Park in the north of England. The paper describes a learning process that integrates different types of knowledge to produce future scenarios that describe possible economic and environmental changes due to a national review of burning practices on heather moorland and blanket bogs. We stress the need for using social network analysis to structure stakeholder engagement and outline how a range of participatory approaches can facilitate more inclusive environmental planning and policy development.
Understanding Loweswater: Interdisciplinary Research in Practice
Authors: Waterton Claire , Norton Lisa , Morris Jake
Published: June 2006

This paper reports on a scoping study, ‘Understanding Loweswater’, funded under the Rural Economy and Land Use (RELU) programme. It highlights the research and policy context supporting the need for this kind of interdisciplinary, stakeholder‐inclusive research and explains the way that the research was carried out in practice. The scoping study identified some of the challenges of the interdisciplinary approach taken, as well as highlighted its potential for solving environmental problems that do not fit within the frame of a single discipline.
Adolescent and Young Adult Suicide: A 10‐Year Retrospective Review of Kentucky Medical Examiner Cases
Authors: Shields Lisa B.E. , Hunsaker Donna M. , Hunsaker John C.
Published: June 2006

ABSTRACT: The compilation of all suicidal causes of death attained the third highest ranking of mortality between the ages of 15 and 24 following unintentional deaths and homicide in the United States, accounting for approximately 4000 deaths in 2002. A variety of biopsychosocial factors may contribute to adolescent suicidal behavior, including psychiatric disorders, risk‐taking behaviors, and lack of a cohesive family unit. The authors conducted a 10‐year (1993–2002) retrospective review of 108 Medical Examiner cases of suicide ages 11–17 and 358 cases ages 18–24 in Kentucky, which represents two thirds of the Coroner cases in the state. The majority of victims were male and Caucasian. The major causes of death were the same for the two age groups, specifically, firearm injury (72.2% and 70.7%), hanging (22.2% and 18.7%), and drug intoxication (2.8% and 5.3%). An integrated Coroner‐Medical Examiner system profits in the public health arena by providing collaborative research data for policy decisions. The prevalence of youth suicide by firearm should prompt further discussion regarding ways to better identify high‐risk adolescents and young adults and restrict pediatric access to unsecured household firearms.
Eccentric rehabilitation exercise increases peritendinous type I collagen synthesis in humans with Achilles tendinosis
Authors: Langberg H. , Ellingsgaard H. , Madsen T. , Jansson J. , Magnusson S. P. , Aagaard P. , Kjær M.
Published: June 2006

It has been shown that 12 weeks of eccentric heavy resistance training can reduce pain in runners suffering from chronic Achilles tendinosis, but the mechanism behind the effectiveness of this treatment is unknown. The present study investigates the local effect of an eccentric training regime on elite soccer players suffering from chronic Achilles tendinosis on the turnover of the peritendinous connective tissue.

Twelve elite male soccer players, of whom six suffered from unilateral tendinosis and six were healthy controls, participated in this study. All participants performed 12 weeks of heavy‐resistance eccentric training apart from their regular training and soccer activity. Before and after the training period the tissue concentration of indicators of collagen turnover was measured by the use of the microdialysis technique. After training, collagen synthesis was increased in the initially injured tendon (n=6; carboxyterminal propeptide of type I collagen (PICP): pre 3.9±2.5 μg/L to post 19.7±5.4 μg/L, P<0.05). The collagen synthesis was unchanged in healthy tendons in response to training (n=6; PICP: pre 8.3±5.2 μg/L to post 11.5±5.0 μg/L, P>0.05). Collagen degradation, measured as carboxyterminal telopeptide region of type I collagen (ICTP), was not affected by training neither in the injured nor in the healthy tendons. The clinical effect of the 12 weeks of eccentric training was determined by using a standardized loading procedure of the Achilles tendons showing a decrease in pain in all the chronic injured tendons (VAS before 44±9, after 13±9; P<0.05), and all subjects were back playing soccer following the eccentric training regime.

The present study demonstrates that chronically injured Achilles tendons respond to 12 weeks of eccentric training by increasing collagen synthesis rate. In contrast, the collagen metabolism in healthy control tendons seems not to be affected by eccentric training. These findings could indicate a relation between collagen metabolism and recovery from injury in human tendons.
Reproducibility and relationship of single‐joint strength vs multi‐joint strength and power in aging individuals
Authors: Holsgaard Larsen A. , Caserotti P. , Puggaard L. , Aagaard P.
Published: June 2006

Introduction: Reliable and sensitive muscle strength/power assessments are essential when evaluating age‐related and/or training‐induced changes in maximal strength and power.

Aim: To investigate the reproducibility and inter‐relationship of single‐joint isokinetic/isometric leg muscle strength vs multi‐joint mechanical muscle function during counter‐movement jump (CMJ) in moderately trained aging individuals (age 72.3±6.6).

Results: The within‐subject coefficient of variation (CVw‐s) for the single‐joint test showed good reproducibility (<10%) for quadriceps and hamstring strength (except for hamstring isometric). Plantar flexion demonstrated good to moderate reproducibility (CVw‐s range: 10.4–17.2%). Excellent to good CVw‐s (<10%) was observed for all concentric CMJ parameters, except for plantar flexor mean work (CVw‐s=13%). Eccentric CMJ parameters demonstrated good to moderate reproducibility (CVw‐s range: 8.1–18.2%). Isokinetic and isometric quadriceps, hamstring and plantar flexor single‐joint strength measurements were found to correlate with several CMJ parameters.

Conclusion: Single‐joint and multi‐joint strength and power assessment tests of the lower limbs appear to be reproducible in aging individuals. Furthermore, associations between single‐joint strength and multi‐joint CMJ power and force variables exist. To evaluate functional capacity in elderly people further investigations must be carried out to identify specific power/strength parameters that are most tightly linked to functional performance.
Decreased shoulder function and pain common in recreational badminton players
Authors: Fahlström M. , Söderman K.
Published: June 2006

The aim of this study was to describe the prevalence and consequences of painful conditions in the shoulder region in recreational badminton players. A questionnaire study was performed on 99 players, of whom 57 were also assessed with Constant score. Previous or present pain in the dominant shoulder was reported by 52% of the players. Sixteen percent of the players had on‐going shoulder pain associated with badminton play. A majority of these players reported that their training habits were affected by the pain. Total Constant score was lower in the painful shoulders. Furthermore, range of active pain‐free shoulder abduction was decreased. However, isometric shoulder strength test showed no differences when compared with pain‐free shoulders. Even though the pain caused functional problems, the players were still playing with on‐going symptoms. The diagnoses were mostly unknown, although history and clinical tests indicate problems resembling subacromial impingement.
Exercise, bone mass and bone size in prepubertal boys: one‐year data from the pediatric osteoporosis prevention study
Authors: Lindén C. , Alwis G. , Ahlborg H. , Gardsell P. , Valdimarsson O. , Stenevi‐Lundgren S. , Besjakov J. , Karlsson M. K.
Published: June 2006

This non‐randomized prospective controlled study evaluates a daily school‐based exercise intervention program of 40 min/school day for 1 year in a population‐based cohort of 81 boys aged 7–9 years. Controls were 57 age‐matched boys assigned to the general school curriculum of 60 min/week. Bone mineral content (BMC; g) and areal bone mineral density (aBMD; g/cm2) were measured with dual X‐ray absorptiometry (DXA) of the total body, the third lumbar vertebra (L3) and the femoral neck (FN). Bone width for L3 and FN was calculated from the lumbar spine and hip scan. No differences between the groups were found at baseline in age, anthropometrics or bone parameters. The mean annual gain in L3 BMC was 5.9 percentage points higher (P<0.001), L3 aBMD a mean 2.1 percentage points higher (P=0.01) and L3 width a mean 2.3 percentage points higher (P=0.001) in the cases than in the controls. When all individuals were included in one cohort, the total duration of exercise including both school‐based and spare‐time training correlated with L3 BMC (r=0.26, P=0.003), L3 aBMD (r=0.18, P=0.04) and L3 width (r=0.24, P=0.006). The study suggests that exercise in pre‐pubertal boys influences the accrual of bone mineral and bone width and that a 1‐year school‐based exercise program confers skeletal benefits, at least in the lumbar spine.
Hypoxia reduces the expression of heme oxygenase‐2 in various types of human cell lines
Authors: Zhang Yongzhao , Furuyama Kazumichi , Kaneko Kiriko , Ding Yuanying , Ogawa Kazuhiro , Yoshizawa Miki , Kawamura Masaki , Takeda Kazuhisa , Yoshida Tadashi , Shibahara Shigeki
Published: June 2006

Heme oxygenase consists of two structurally related isozymes, heme oxygenase‐1 and and heme oxygenase‐2, each of which cleaves heme to form biliverdin, iron and carbon monoxide. Expression of heme oxygenase‐1 is increased or decreased depending on cellular microenvironments, whereas little is known about the regulation of heme oxygenase‐2 expression. Here we show that hypoxia (1% oxygen) reduces the expression levels of heme oxygenase‐2 mRNA and protein after 48 h of incubation in human cell lines, including Jurkat T‐lymphocytes, YN‐1 and K562 erythroleukemia, HeLa cervical cancer, and HepG2 hepatoma, as judged by northern blot and western blot analyses. In contrast, the expression level of heme oxygenase‐1 mRNA varies under hypoxia, depending on the cell line; it was increased in YN‐1 cells, decreased in HeLa and HepG2 cells, and remained undetectable in Jurkat and K562 cells. Moreover, heme oxygenase‐1 protein was decreased in YN‐1 cells under the conditions used, despite the induction of heme oxygenase‐1 mRNA under hypoxia. The heme oxygenase activity was significantly decreased in YN‐1, K562 and HepG2 cells after 48 h of hypoxia. To explore the mechanism for the hypoxia‐mediated reduction of heme oxygenase‐2 expression, we showed that hypoxia shortened the half‐life of heme oxygenase‐2 mRNA (from 12 h to 6 h) in YN‐1 cells, without affecting the half‐life of heme oxygenase‐1 mRNA (9.5 h). Importantly, the heme contents were increased in YN‐1, HepG2 and HeLa cells after 48 h of incubation under hypoxia. Thus, the reduced expression of heme oxygenase‐2 may represent an important adaptation to hypoxia in certain cell types, which may contribute to the maintenance of the intracellular heme level.
FixJ: a Major Regulator of the Oxygen Limitation Response and Late Symbiotic Functions of
Sinorhizobium meliloti
Authors: Bobik Christine , Meilhoc Eliane , Batut Jacques
Published: June 2006

Sinorhizobium meliloti
exists either in a free-living state in the soil or in
symbiosis within legume nodules, where the bacteria differentiate into
nitrogen-fixing bacteroids. Expression of genes involved in nitrogen
fixation and associated respiration is governed by two intermediate
regulators, NifA and FixK, respectively, which are controlled by a
two-component regulatory system FixLJ in response to low-oxygen
conditions. In order to identify the FixLJ regulon, gene expression
profiles were determined in microaerobic free-living cells as well as
during the symbiotic life of the bacterium for the wild type and a
fixJ
null-mutant strain. We identified 122 genes activated by
FixJ in either state, including 87 novel targets. FixJ controls 74% of
the genes induced in microaerobiosis (2% oxygen) and the majority of
genes expressed in mature bacteroids. Ninety-seven percent of
FixJ-activated genes are located on the symbiotic plasmid pSymA.
Transcriptome profiles of a
nifA
and a
fixK
mutant
showed that NifA activates a limited number of genes, all specific to
the symbiotic state, whereas FixK controls more than 90 genes, involved
in free-living and/or symbiotic life. This study also revealed that
FixJ has no other direct targets besides those already known. FixJ is
involved in the regulation of functions such as denitrification or
amino acid/polyamine metabolism and transport. Mutations in selected
novel FixJ targets did not affect the ability of the bacteria to form
nitrogen-fixing nodules on
Medicago sativa
roots. From these
results, we propose an updated model of the FixJ
regulon.
Site-Directed Amino Acid Substitutions in the Hydroxylase α Subunit of Butane Monooxygenase from
Pseudomonas butanovora
: Implications for Substrates Knocking at the Gate
Authors: Halsey Kimberly H. , Sayavedra-Soto Luis A. , Bottomley Peter J. , Arp Daniel J.
Published: June 2006

Butane monooxygenase (BMO) from
Pseudomonas butanovora
has high homology to soluble methane monooxygenase (sMMO), and both oxidize a wide range of hydrocarbons; yet previous studies have not demonstrated methane oxidation by BMO. Studies to understand the basis for this difference were initiated by making single-amino-acid substitutions in the hydroxylase α subunit of butane monooxygenase (BMOH-α) in
P. butanovora
. Residues likely to be within hydrophobic cavities, adjacent to the diiron center, and on the surface of BMOH-α were altered to the corresponding residues from the α subunit of sMMO. In vivo studies of five site-directed mutants were carried out to initiate mechanistic investigations of BMO. Growth rates of mutant strains G113N and L279F on butane were dramatically slower than the rate seen with the control
P. butanovora
wild-type strain (Rev WT). The specific activities of BMO in these strains were sevenfold lower than those of Rev WT. Strains G113N and L279F also showed 277- and 5.5-fold increases in the ratio of the rates of 2-butanol production to 1-butanol production compared to Rev WT. Propane oxidation by strain G113N was exclusively subterminal and led to accumulation of acetone, which
P. butanovora
could not further metabolize. Methane oxidation was measurable for all strains, although accumulation of 23 μM methanol led to complete inhibition of methane oxidation in strain Rev WT. In contrast, methane oxidation by strain G113N was not completely inhibited until the methanol concentration reached 83 μM. The structural significance of the results obtained in this study is discussed using a three-dimensional model of BMOH-α.
Involvement of Y-Family DNA Polymerases in Mutagenesis Caused by Oxidized Nucleotides in
Escherichia coli
Authors: Yamada Masami , Nunoshiba Tatsuo , Shimizu Masatomi , Gruz Petr , Kamiya Hiroyuki , Harashima Hideyoshi , Nohmi Takehiko
Published: June 2006

Escherichia coli
DNA polymerase IV incorporated 2-hydroxy-dATP opposite template guanine or thymine and 8-hydroxy-dGTP exclusively opposite adenine in vitro. Mutator phenotypes in
sod/fur
strains were substantially diminished by deletion of
dinB
and/or
umuDC
. DNA polymerases IV and V may be involved in mutagenesis caused by incorporation of the oxidized deoxynucleoside triphosphates.
Polar Localization of the Autotransporter Family of Large Bacterial Virulence Proteins
Authors: Jain Sumita , van Ulsen Peter , Benz Inga , Schmidt M. Alexander , Fernandez Rachel , Tommassen Jan , Goldberg Marcia B.
Published: June 2006

Autotransporters are an extensive family of large secreted virulence-associated proteins of gram-negative bacteria. Secretion of such large proteins poses unique challenges to bacteria. We demonstrate that autotransporters from a wide variety of rod-shaped pathogens, including IcsA and SepA ofShigella flexneri, AIDA-I of diffusely adherentEscherichia coli, and BrkA ofBordetella pertussis, are localized to the bacterial pole. The restriction of autotransporters to the pole is dependent on the presence of a complete lipopolysaccharide (LPS), consistent with known effects of LPS composition on membrane fluidity. Newly synthesized and secreted BrkA is polar even in the presence of truncated LPS, and all autotransporters examined are polar in the cytoplasm prior to secretion. Together, these findings are consistent with autotransporter secretion occurring at the poles of rod-shaped gram-negative organisms. Moreover, NalP, an autotransporter of spherically shapedNeisseria meningitidiscontains the molecular information to localize to the pole ofEscherichia coli. InN. meningitidis, NalP is secreted at distinct sites around the cell. These data are consistent with a model in which the secretion of large autotransporters occurs via specific conserved pathways located at the poles of rod-shaped bacteria, with profound implications for the underlying physiology of the bacterial cell and the nature of bacterial pathogen-host interactions.
A NEW S-S′ PAIR CREATION RATE EXPRESSION IMPROVING UPON ZENER CURVES FOR I-E PLOTS
Authors: BECKWITH A. W.
Published: June 2006

To simplify phenomenology modeling used for charge density wave (CDW) transport, we apply a wavefunctional formulation of tunneling Hamiltonians to a physical transport problem characterized by a perturbed washboard potential. To do so, we consider tunneling between states that are wavefunctionals of a scalar quantum field ϕ. I-E curves that match Zener curves — used to fit data experimentally with wavefunctionals congruent with the false vacuum hypothesis. This has a very strong convergence with the slope of graphs of electron-positron pair production representations. The newly derived results include a threshold electric field explicitly as a starting point without an arbitrary cut off value for the start of the graphed results, thereby improving on both the Zener plots and Lin's generalization of Schwingers 1950 electron-positron nucleation values results for low dimensional systems. The similarities in plot behavior of the current values after the threshold electric field values argue in favor of the Bardeen pinning gap paradigm proposed for quasi-one-dimensional metallic transport problems.
On the performance of the particle swarm optimization algorithm with various inertia weight variants for computing optimal control of a class of hybrid systems
Authors: Arumugam M. Senthil , Rao M. V. C.
Published: June 2006

This paper presents an alternative and efficient method for solving the optimal control of single‐stage hybrid manufacturing systems which are composed with two different categories: continuous dynamics and discrete dynamics. Three different inertia weights, a constant inertia weight (CIW), time‐varying inertia weight (TVIW), and global‐local best inertia weight (GLbestIW), are considered with the particle swarm optimization (PSO) algorithm to analyze the impact of inertia weight on the performance of PSO algorithm. The PSO algorithm is simulated individually with the three inertia weights separately to compute the optimal control of the single‐stage hybrid manufacturing system, and it is observed that the PSO with the proposed inertia weight yields better result in terms of both optimal solution and faster convergence. Added to this, the optimal control problem is also solved through real coded genetic algorithm (RCGA) and the results are compared with the PSO algorithms. A typical numerical example is also included in this paper to illustrate the efficacy and betterment of the proposed algorithm. Several statistical analyses are carried out from which can be concluded that the proposed method is superior to all the other methods considered in this paper.
Spacelike hypersurfaces in de Sitter space with constant higher‐order mean curvature
Authors: Cai Kairen , Xu Huiqun
Published: June 2006

The authors apply the generalized Minkowski formula to set up a
spherical theorem. It is shown that a compact connected
hypersurface with positive constant higher‐order mean curvature Hr for some fixed r , 1 ≤ r ≤ n, immersed in the de
Sitter space must be a sphere.
A density result in vector optimization
Authors: Zaslavski Alexander J.
Published: June 2006

We study a class of vector minimization problems
on a complete metric space such that all its bounded closed
subsets are compact. We show that a subclass of minimization
problems with a nonclosed set of minimal values is dense in
the whole class of minimization problems.
Matrix transformations between the spaces of Cesàro sequences and invariant means
Authors: Mursaleen M. , Savaş E. , Aiyub M. , Mohiuddine S. A.
Published: June 2006

The main purpose of this paper is to characterize the classes of
matrices (ces[(p), (q)], cσ)
and , where cσ is the space of all
bounded sequences all of whose σ‐ means are equal,
is the space of σ‐ bounded
sequences, and ces[(p), (q)] is the generalized Cesàro sequence
space.
Decompositions of a C‐algebra
Authors: Rao G. C. , Sundarayya P.
Published: June 2006

We prove that if A is a C‐algebra, then for each a ∈ A, Aa = {x ∈ A/x ≤ a} is itself a C‐algebra and is isomorphic to the quotient algebra A/θa of A where θa = {(x, y) ∈ A × A/a∧x = a∧y}. If A is C‐algebra with T, we prove that for every a ∈ B(A), the centre of A, A is isomorphic to and that if A is isomorphic A1 × A2, then there exists a ∈ B(A) such that A1 is isomorphic Aa and A2 is isomorphic to . Using this decomposition theorem, we prove that if a, b ∈ B(A) with a∧b = F, then Aa is isomorphic to Ab if and only if there exists an isomorphism φ on A such that φ(a) = b.
Generalized multidimensional Hilbert transformsin Clifford analysis
Authors: Brackx Fred , De Knock Bram , De Schepper Hennie
Published: June 2006

Two specific generalizations of the multidimensional Hilbert
transform in Clifford analysis are constructed. It is shown that
though in each of these generalizations some traditional
properties of the Hilbert transform are inevitably lost, new
bounded singular operators emerge on Hilbert or Sobolev spaces of
L2‐functions.
A Bacillus sphaericus Based Biosensor for Monitoring Nickel Ions in Industrial Effluents and Foods
Authors: Verma Neelam , Singh Minni
Published: June 2006

A microbial‐based biosensor has been developed based on enzyme inhibition bioassay for monitoring the presence of Ni(II) in real‐time samples. The sensing element is immobilized Bacillus sphaericus MTCC 5100 yielding urease enzyme. The transducer is an ion selective electrode in conjunction with a potentiometer. Heavy metals are potentially toxic to human beings. Nickel is associated with causing adverse health effects such as dermatitis and vertigo, in humans. Toxicity is manifested by affecting T‐cell system and suppressing the activity of natural killer cells. Nickel finds applications in electroplating, coinage, electrodes, jewellery, alloys. The foods rich in Ni(II) are nuts, beans, oats, and wheat. The range of Ni(II) detection by the developed biosensor is 0.03–0.68 nM (0.002–0.04 ppb) with a response time of 1.5 minutes. For application, the Ni(II) effluent was procured from an electroplating industrial unit and was found to have a concentration of 100.0 ppm Ni(II). In foods, wheat flour sample was acid digested and Ni(II) was specifically complexed in the presence of other cations, and had an Ni(II) concentration of 0.044 ppm. The developed system has a reliability of 91.5% and 90.6%, respectively, for the samples and could possibly replace the existing conventional techniques of analysis.
Testing a differential‐algebraic equation solver in long‐term voltage stability simulation
Authors: Pessanha José E. O. , Paz Alex A.
Published: June 2006

This work evaluates the performance of a particular differential‐algebraic equation solver, referred to as DASSL, in power system voltage stability computer applications. The solver is tested for a time domain long‐term voltage stability scenario, including transient disturbances, using a real power system model. Important insights into the mechanisms of the DASSL solver are obtained through the use of this real model, including control devices relevant to the simulated phenomena. The results indicate that if properly used, the solver can be a powerful numerical tool in time domain assessment of long‐term power system stability since it comprises, among several important features, suitable and very efficient variable order and variable step‐size numerical techniques. These characteristics are very important when CPU time is a great concern, which is the case when the power system operator needs reliable results in a short period of time. Prior to the present work, this solver has never been applied in power system stability computer analysis in time domain considering slow and fast phenomena.
Determination of inspection schedules of equipment by variational method
Authors: Okumura Susumu
Published: June 2006

Maintained equipment can be subject to random failures. If failures are evident, they can be detected immediately when they occur. On the other hand, hidden failures that are not revealed during the performance of regular duties may be detected by inspection process. If concerned equipment has hidden failures, loss is assumed to incur from the moment its failure until the time when it is detected. Optimal inspection schedule should be considered when inspection is costly. In this study, optimal inspection schedules for equipment are derived by the variational method employing the inspection density function. For the case in which the time‐to‐failure distribution of equipment is given, a conditional equation that optimal inspection schedules should satisfy is derived. Furthermore, when the time‐to‐failure distribution is unknown, an ordinary differential equation that optimal inspection schedules should satisfy is obtained. Optimal inspection schedules in a closed form and numerical examples are shown for some potential loss rate functions.