CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 2 2003
Krzysztof Boryczko
Abstract Simulating natural phenomena at greater accuracy results in an explosive growth of data. Large-scale simulations with particles currently involve ensembles consisting of between 106 and 109 particles, which cover 105,106 time steps. Thus, the data files produced in a single run can reach from tens of gigabytes to hundreds of terabytes. This data bank allows one to reconstruct the spatio-temporal evolution of both the particle system as a whole and each particle separately. Realistically, for one to look at a large data set at full resolution at all times is not possible and, in fact, not necessary. We have developed an agglomerative clustering technique, based on the concept of a mutual nearest neighbor (MNN). This procedure can be easily adapted for efficient visualization of extremely large data sets from simulations with particles at various resolution levels. We present the parallel algorithm for MNN clustering and its timings on the IBM SP and SGI/Origin 3800 multiprocessor systems for up to 16 million fluid particles. The high efficiency obtained is mainly due to the similarity in the algorithmic structure of MNN clustering and particle methods. We show various examples drawn from MNN applications in visualization and analysis of the order of a few hundred gigabytes of data from discrete particle simulations, using dissipative particle dynamics and fluid particle models. Because data clustering is the first step in this concept extraction procedure, we may employ this clustering procedure to many other fields such as data mining, earthquake events and stellar populations in nebula clusters. Copyright © 2003 John Wiley & Sons, Ltd. [source]

RESISTING CRIME: THE EFFECTS OF VICTIM ACTION ON THE OUTCOMES OF CRIMES

CRIMINOLOGY, Issue 4 2004
JONGYEON TARK
This study assessed the impact of sixteen types of victim self protection (SP) actions on three types of outcomes of criminal incidents: first, whether the incident resulted in property loss, second, whether it resulted in injury to the victim, and, third, whether it resulted in serious injury. Data on 27, 595 personal contact crime incidents recorded in the National Crime Victimization Survey for the 1992 to 2001 decade were used to estimate multivariate models of crime outcomes with logistic regression. Results indicated that self-protection in general, both forceful and nonforceful, reduced the likelihood of property loss and injury, compared to nonresistance. A variety of mostly forceful tactics, including resistance with a gun, appeared to have the strongest effects in reducing the risk of injury, though some of the findings were unstable due to the small numbers of sample cases. The appearance, in past research, of resistance contributing to injury was found to be largely attributable to confusion concerning the sequence of SP actions and injury. In crimes where both occurred, injury followed SP in only 10 percent of the incidents. Combined with the fact that injuries following resistance are almost always relatively minor, victim resistance appears to be generally a wise course of action. [source]

Evaluation of sixth grade primary schoolchildren's knowledge about avulsion and dental reimplantation

DENTAL TRAUMATOLOGY, Issue 4 2009
Lithiene Ribeiro Castilho
The avulsed tooth should be immediately reimplanted in its alveolus. This procedure can be performed by anyone at the accident site and not only by dental surgeons. Therefore, the purpose of this study is to evaluate the knowledge of sixth graders of the city of Araçatuba, SP, about dental avulsion and tooth reimplantation through a structured and standardized survey. Our sample consisted of 778 students. The data collected was processed using the program epiinfo 2000. Most students were around 12 years of age and 94.5% related to practice some kind of sports. Results demonstrated that the possibility of tooth reimplantation after dental avulsion is not acknowledged among these students and dental traumatism was associated to caries, toothache, and use of orthodontic appliances. Only 18.9% of the students associated dental traumatism to an impact trauma; 3.6% would store the tooth in milk, and 3.1% believed the tooth could be reimplanted by anyone present at the accident site. In summary, the results show an overall the lack of knowledge about dental traumatism and highlight the need of special programs designed to educate school-aged students about emergency procedures to handle cases of dental traumatisms. [source]

Prevalence of social phobia and its comorbidity with psychiatric disorders in Iran

DEPRESSION AND ANXIETY, Issue 7 2006
Mohammad-Reza Mohammadi M.D.
Abstract This study explored the prevalence of social phobia (SP) in the general population of Iran, the sociodemographic characteristics of subjects with SP, and its comorbidity with the other lifetime psychiatric disorders. Our study was part of the nationwide study on the prevalence of psychiatric disorders in Iran. Overall, 25,180 Iranian subjects, age 18 years and over, from urban and rural areas of Iran were selected by a clustered random sampling method and interviewed face-to-face by 250 trained clinical psychologists using DSM-IV diagnostic criteria. Out of 12,398,235 households, 7,795 households in the form of 1,559 clusters of five households were selected. The statistical framework was based on the household lists available from the Department of Health in the provinces. The response rate was 90%. The lifetime prevalence of SP was 0.82%. The rate was 0.4% in males and 1.3% in females. The rate was higher in younger age groups and widows/widowers. It was not related to educational level and residential area. Specific phobia (66.7%), obsessive,compulsive disorder (17.4%), major depressive disorder (15%), and panic disorder (12.1%) were the most common lifetime psychiatric disorders among subjects with SP. The rate of SP in Iran is more similar to that in other Asian countries, and it is lower than that in Western countries. The rate of other psychiatric disorders among subjects with SP is more than that in the general population, and the most common psychiatric disorders were the other anxiety disorders and major depressive disorder. Depression and Anxiety 23:405,411, 2006 © 2006 Wiley-Liss, Inc. [source]

Selective attention in anxiety: Distraction and enhancement in visual search

DEPRESSION AND ANXIETY, Issue 1 2003
Mike Rinck
Abstract According to cognitive models of anxiety, anxiety patients exhibit an attentional bias towards threat, manifested as greater distractibility by threat stimuli and enhanced detection of them. Both phenomena were studied in two experiments, using a modified visual search task, in which participants were asked to find single target words (GAD-related, speech-related, neutral, or positive) hidden in matrices made up of distractor words (also GAD-related, speech-related, neutral, or positive). Generalized anxiety disorder (GAD) patients, social phobia (SP) patients afraid of giving speeches, and healthy controls participated in the visual search task. GAD patients were slowed by GAD-related distractor words but did not show statistically reliable evidence of enhanced detection of GAD-related target words. SP patients showed neither distraction nor enhancement effects. These results extend previous findings of attentional biases observed with other experimental paradigms. Depression and Anxiety 18:18,28, 2003. © 2003 Wiley-Liss, Inc. [source]

Smooth ocular pursuit in Chiari type II malformation

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 4 2007
Michael S Salman MRCP PhD
Chiari type II malformation (CII) is a congenital anomaly of the cerebellum and brainstem, both important structures for processing smooth ocular pursuit. CII is associated with myelomeningocele and hydrocephalus. We investigated the effects of CII on smooth pursuit (SP) eye movements, and determined the effects of spinal lesion level, number of shunt revisions, nystagmus, and brain dysmorphology on SP. SP was recorded using an infrared eye tracker in 21 participants with CII (11 males, 10 females; age range 8-19y, mean 14y 3mo [SD 3y 2mo]). Thirty-eight healthy children (21 males, 17 females) constituted the comparison group. Participants followed a visual target moving sinusoidally at ± 10° amplitude, horizontally and vertically at 0.25 or 0.5Hz. SP gains, the ratio of eye to target velocities, were abnormal in the CII group with nystagmus (n= 8). The number of shunt revisions (range 0-10), brain dysmorphology, or spinal lesion level (n= 15 for lower and n= 6 for upper spinal lesion level) did not correlate with SP gains. SP is impaired in children with CII and nystagmus. Abnormal pursuit might be related to the CII dysgenesis or to effects of hydrocephalus. The lack of effect of shunt revisions and abnormal tracking in participants with nystagmus provide evidence that it is related primarily to the cerebellar and brainstem malformation. [source]

Epidemiology and natural course of social fears and social phobia,

ACTA PSYCHIATRICA SCANDINAVICA, Issue 2003
H.-U. Wittchen
Objective: To summarize epidemiological studies providing data on prevalence, incidence, comorbidity, natural course, risk factors and consequences of social phobia (SP). Method: Data from cross-sectional studies and prospective longitudinal studies in particular are considered. Results: These studies portray SP as a frequent mental disorder, which begins typically in early adolescence, and is highly comorbid with other anxiety disorders, as well as secondary depression and substance abuse disorders. Several possible risk factors have already been identified for the onset and unfavorable course of SP; some of them have been tested in prospective longitudinal studies. SP is a chronic disorder when compared with other mental disorders and when subclinical symptomatic levels are considered. Impairment caused by SP is considerable and increases over a patient's life span. The negative impact of SP is not only reflected in subjective well-being and reduced quality of life but also in social role functioning, and it impacts negatively on career progression. Conclusion: Prospective longitudinal studies in representative samples drawn from the general population provide information that allows the overall direct and indirect costs of the disorder (treatment costs, disability, social welfare) to be determined, and enables an improvement in long-term care strategies as well as preventive efforts to be established. [source]

Comparison of vasodilator effects of substance P in human forearm vessels of normoalbuminuric Type 1 diabetic and non-diabetic subjects

DIABETIC MEDICINE, Issue 3 2000
D. R. Meeking
Summary Aims To compare the vasodilatory responses to substance P in human forearm vessels in Type 1 normoalbuminuric diabetic and non-diabetic subjects. Methods Forearm blood flow (FBF) was measured using a plethysmography technique in 12 normoalbuminuric Type 1 diabetic subjects (six males, six females) (HbA1C 8.2 ± 0.3% (mean ±,sem)) and 12 non-diabetic healthy control subjects in response to the infusion of the vasodilators substance P (SP), acetylcholine (ACh) and nitroprusside. Results There was no significant difference in baseline FBF between the two groups (2.80 ± 0.29 ml/min per 100 ml forearm tissue (diabetic group) vs. 2.85 ± 0.37 ml/min per 100 ml (non-diabetic group), P = 0.45). Infusion of SP was associated with an incremental increase in FBF in the diabetic (0.6, 2 and 6 ng/min , 6.08 ± 1.07, 7.82 ± 1.08 and 9.48 ± 1.14 ml/min per 100 ml, respectively) and the non-diabetic group (0.6, 2 and 6 ng/min , 5.41 ± 0.80, 6.93 ± 0.96 and 9.25 ± 1.11 ml/min per 100 ml, respectively). Similarly, an incremental rise in FBF was observed during infusion of ACh (diabetic group: 7.5, 15 and 30 ,g/min , 7.14 ± 1.22, 8.91 ± 1.40 and 11.67 ± 1.93 ml/min per 100 ml, respectively; non-diabetic group: 7.5, 15 and 30 ,g/min , 5.87 ± 0.81, 7.49 ± 0.96 and 10.74 ± 1.29 ml/min per 100 ml, respectively). When FBF was expressed as percentage change from baseline, there was no significant difference in vasodilatory responses between the two groups for SP (0.6 ng/min, P = 0.21; 2 ng/min, P = 0.19; 6 ng/min, P = 0.19) or ACh (7.5 ,g/min, P = 0.20; 15 ,g/min, P = 0.20; 30 ,g/min, P = 0.35). Conclusions This study suggests that endothelium-dependent vasodilatory responses to SP (and ACh) are not impaired in Type 1 diabetic subjects with normal urinary albumin excretion. [source]

Wittgenstein's Builders and Perry's Objection to Sentence Priority

DIALECTICA, Issue 1 2002
Eli Dresner
In the first section of this paper I present a view of linguistic meaning that I label 'Sentence Priority'(SP): the position that semantically primitive language-world contact is made at the level of complete sentences (rather than the level of sentence parts). Then, in the main part of the paper, I consider and reject an objection against Sentence Priority raised by John Perry, an objection that appeals to Wittgenstein's builders parable. Perry argues that the builder's utterances (,Slab',,Pillar', etc.) are utterances of self-standing nouns, and that therefore they constitute a counter-example to SP. A sound assessment of Perry's argument, however, depends on a clear distinction between two cases: one in which the four expressions mentioned in Wittgenstein's example exhaust the builders'expressive powers, and one in which they do not. Once these cases are distinguished it can be seen that in neither does Perry's argument go through. [source]

Simultaneous determination of metronidazole and spiramycin in bulk powder and in tablets using different spectrophotometric techniques

DRUG TESTING AND ANALYSIS, Issue 1 2010
Fatma I. Khattab
Abstract Metronidazole (MZ) is an anti-infective drug used in the treatment of anaerobic bacterial and protozoa infections in humans. It is also used as a vetinary antiparasitic drug. Spiramycin (SP) is a medium-spectrum antibiotic with high effectiveness against Gram-positive bacteria. Three simple, sensitive, selective and precise spectrophotometric methods were developed and validated for the simultaneous determination of MZ and SP in their pure form and in pharmaceutical formulations. In methods A and B, MZ was determined by the application of direct spectrophotometry and by measuring its zero-order (D0) absorption spectra at its ,max = 311 nm. In method A, SP was determined by the application of first derivative spectrophotometry (D1) and by measuring the amplitude at 218.3 nm. In method B, the first derivative of the ratio spectra (DD1) was applied, and SP was determined by measuring the peak amplitude at 245.6 nm. Method C entailed mean centring of the ratio spectra (MCR), which allows the determination of both MZ and SP. The methods developed were used for the determination of MZ and SP over a concentration range of 5,25 µg ml,1. The proposed methods were used to determine both drugs in their pure, powdered forms with mean percentage recoveries of 100.16 ± 0.73 for MZ in methods A and B, 101.10 ± 0.90 in method C, 100.09 ± 0.70, 100.02 ± 0.88 and 100.49 ± 1.26 for SP in methods A, B and C, respectively. The proposed methods were proved using laboratory-prepared mixtures of the two drugs and were successfully applied to the analysis of MZ and SP in tablet formulation without any interference from each other or from the excipients. The results obtained by applying the proposed methods were compared statistically with a reported HPLC method and no significant difference was observed between these methods regarding both accuracy and precision. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Enterococcus faecalis with the gelatinase phenotype regulated by the fsr operon and with biofilm-forming capacity are common in the agricultural environment

ENVIRONMENTAL MICROBIOLOGY, Issue 6 2009
Lilia Macovei
Summary The prevalence of gelatinase activity and biofilm formation among environmental enterococci was assessed. In total, 396 enterococcal isolates from swine and cattle faeces and house flies from a cattle farm were screened for gelatinase activity. The most prevalent phenotype on Todd,Hewitt agar with 1.5% skim milk was the weak protease (WP) (72.2% of isolates), followed by the strong protease (SP) 18.7%, and no protease (NP) (9.1%). The majority of WP isolates was represented by Enterococcus hirae (56.9%), followed by Enterococcus faecium (25.9%), Enterococcus casseliflavus (10.4%), Enterococcus gallinarum (5.2%) and Enterococcus saccharolyticus (1.7%). All WP isolates were negative for gelE (gelatinase) and sprE (serine protease) as well as the fsrABDC operon that regulates the two proteases, and only four isolates (7.0%) formed biofilms in vitro. All SP isolates were Enterococcus faecalis positive for the fsrABDC, gelE, sprE genes and the majority (91.2%) formed a biofilm. Diversity of NP isolates was relatively evenly distributed among E. hirae, E. faecium, E. casseliflavus, E. gallinarum, Enterococcus durans, E. saccharolyticus and Enterococcus mundtii. All NP isolates were negative for the fsr operon and only four E. hirae (11.1%) formed a biofilm. Of further interest was the loss of the gelatinase phenotype (18.9% of isolates) from SP isolates after 4 month storage at 4,8°C and several passages of subculture. Results of reverse transcription PCR analysis indicated that mRNA was produced for all the genes in the frs operon and sequencing of the gelE gene did not reveal any significant mutations. However, gelatinase was not detectable by Western blot analysis. Our study shows that E. faecalis with the complete fsr operon and the potential to form a biofilm are relatively common in the agricultural environment and may represent a source/reservoir of clinically relevant strains. In addition, many environmental enterococci, especially E. hirae, produce an unknown WP that can hydrolyse casein but does not contribute to biofilm formation. The stability of the gelatinase phenotype in E. faecalis and its regulation will require additional studies. [source]

MHC class II-independent CD25+ CD4+ CD8,,,+ ,,, T cells attenuate CD4+ T cell-induced transfer colitis

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2004
Tamara Krajina
Abstract CD4+ ,,, T cell populations that develop in mice deficient in MHC class II (through ,knockout' of either the A,, or the A, chain of the I-Ab molecule) comprise a major ,single-positive' (SP) CD4+ CD8, subset (60,90%) and a minor ,double-positive' (DP) CD4+ CD8,,,+ subset (10,40%). Many DP T cells found in spleen, mesenteric lymph nodes (MLN) and colonic lamina propria (cLP) express CD25, CD103 and Foxp3. Adoptive transfer of SP but not DP T cells from A,,/, or A,,/, B6 mice into congenic RAG,/, hosts induces colitis. Transfer of SP T cells repopulates the host with only SP T cells; transfer of DP T cells repopulates the host with DP and SP T cells. Anti-CD25 antibody treatment of mice transplanted with DP T cells induces severe, lethal colitis; anti-CD25 antibody treatment of mice transplanted with SP T cells further aggravates the course of severe colitis. Hence, regulatory CD25+ T cells within (or developing from) the DP T cell population of MHC class II-deficient mice control the colitogenic potential of CD25, CD4+ T cells. [source]

Excitatory actions of substance P in the rat lateral posterior nucleus

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2010
Kush Paul
Abstract The lateral posterior nucleus (LP) receives inputs from both neocortex and superior colliculus (SC), and is involved with integration and processing of higher-level visual information. Relay neurons in LP contain tachykinin receptors and are innervated by substance P (SP)-containing SC neurons and by layer V neurons of the visual cortex. In this study, we investigated the actions of SP on LP relay neurons using whole-cell recording techniques. SP produced a graded depolarizing response in LP neurons along the rostro-caudal extent of the lateral subdivision of LP nuclei (LPl), with a significantly larger response in rostral LPl neurons compared with caudal LPl neurons. In rostral LPl, SP (5,2000 nm) depolarized nearly all relay neurons tested (> 98%) in a concentration-dependent manner. Voltage-clamp experiments revealed that SP produced an inward current associated with a decreased conductance. The inward current was mediated primarily by neurokinin receptor (NK)1 tachykinin receptors, although significantly smaller inward currents were produced by specific NK2 and NK3 receptor agonists. The selective NK1 receptor antagonist RP67580 attenuated the SP-mediated response by 71.5% and was significantly larger than the attenuation of the SP response obtained by NK2 and NK3 receptor antagonists, GR159897 and SB222200, respectively. The SP-mediated response showed voltage characteristics consistent with a K+ conductance, and was attenuated by Cs+, a K+ channel blocker. Our data suggest that SP may modulate visual information that is being processed and integrated in the LPl with inputs from collicular sources. [source]

Cocaine- and amphetamine-regulated transcript peptide (CART) is present in peptidergic C primary afferents and axons of excitatory interneurons with a possible role in nociception in the superficial laminae of the rat spinal cord

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2007
Márk Kozsurek
Abstract Cocaine- and amphetamine-regulated transcript peptides (CART) have been implicated in the regulation of several physiological functions, including pain transmission. A dense plexus of CART-immunoreactive fibres has been described in the superficial laminae of the spinal cord, which are key areas in sensory information and pain processing. In this study, we used antibody against CART peptide, together with markers for various types of primary afferents, interneurons and descending systems to determine the origin of the CART-immunoreactive axons in the superficial laminae of the rat spinal cord. Calcitonin gene-related peptide (CGRP), a marker for peptidergic primary afferents in the dorsal horn, was present in 72.6% and 34.8% of CART-immunoreactive axons in lamina I and II, respectively. The majority of these fibres also contained substance P (SP), while a few were somatostatin (SOM)-positive. The other subpopulation of CART-immunoreactive boutons in lamina I and II also expressed SP and/or SOM without CGRP, but contained vesicular glutamate transporter 2, which is present mainly in excitatory interneuronal terminals. Our data demonstrate that the majority of CART-immunoreactive axons in the spinal dorsal horn originate from peptidergic nociceptive primary afferents, while the rest arise from excitatory interneurons that contain SP or SOM. This strongly suggests that CART peptide can affect glutamatergic neurotransmission as well as the release and effects of SP and SOM in nociception and other sensory processes. [source]

c-Src kinase activation regulates preprotachykinin gene expression and substance P secretion in rat sensory ganglia

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2003
Orisa J. Igwe
Abstract Increased synthesis of substance P (SP) in the dorsal root ganglia (DRG) and enhanced axonal transport to and secretion from the primary afferent sensory neurons might enhance pain signalling in the spinal dorsal horn by modifying pronociceptive pathways. IL-1, increases SP synthesis by enhancing the expression of preprotachykinin (PPT) mRNA encoding for SP and other tachykinins in the DRG. Stimulation of IL-1 receptor by IL-1, may induce the phosphorylation of tyrosine residues in many effector proteins through the activation of p60c-src kinase. The hypothesis that the synthesis of SP in and secretion from the primary sensory ganglia are regulated by the activation of p60c-src kinase induced by IL-1, was tested. Pretreatment of DRG neurons in culture with herbimycin A, genistein or PP2, three structurally different nonreceptor tyrosine kinase inhibitors that act by different mechanisms, decreased the kinase activity of p60c-src induced by the activation of IL-1 receptor. PP3, a negative control for the Src family of tyrosine kinase inhibitor PP2 had no effect. Herbimycin A and genistein also decreased IL-1,-induced expression of PPT mRNA-encoding transcripts and the levels of SP-li synthesized in the cells and secreted into the culture medium in a concentration-dependent manner. SB 203580 [a p38 mitogen-activated protein kinase (p38 MAPK) inhibitor] and PD 98059 (a p44/42 MAPK kinase inhibitor) were ineffective in modulating IL-1,-induced SP synthesis and secretion, and p60c-src kinase activity in DRG neurons. Whereas, IL-1 receptor antagonist and cycloheximide inhibited IL-1,-evoked secretion of SP-like immunoreactivity (SP-li), actinomycin D decreased it significantly but did not entirely abolish it. These findings show that phosphorylation of specific protein tyrosine residue(s) following IL-1 receptor activation might play a key role in IL-1, signalling to modulate PPT gene expression and SP secretion in sensory neurons. In view of the role of SP as an immunomodulator, these studies provide a new insight into neural-immune intercommunication in pain regulation in the sensory ganglia through the IL-1,-induced p60c-src activation. [source]

Neuronal nitric oxide synthase (nNOS) mRNA is down-regulated, and constitutive NOS enzymatic activity decreased, in thoracic dorsal root ganglia and spinal cord of the rat by a substance P N-terminal metabolite

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2001
Katalin J. Kovacs
Abstract Nitric oxide (NO) in the spinal cord plays a role in sensory and autonomic activity. Pain induced by acetic acid in the abdominal stretch (writhing) assay and hyperalgesia associated with chronic pain are highly sensitive to NO synthase (NOS) inhibitors. Because substance P (SP) is released and up-regulated in some models of chronic pain, we hypothesized that an accumulation of SP metabolites may influence NOS expression and activity. To test this hypothesis, we examined the effect of intrathecally (i.t.) injected substance P (1-7) [SP(1-7)], the major metabolite of SP in the rat, on neuronal NOS (nNOS) mRNA in the thoracic and lumbar spinal cord, dorsal root ganglia (DRG) and on the corresponding constitutive NOS (cNOS) enzyme activity. Detected using quantitative RT-PCR, nNOS mRNA content in the thoracic spinal cord was decreased 6 h after injection of 5 µmol of SP(1-7) and returned to control 2 days later. In thoracic DRG, nNOS mRNA was reduced 48 h after SP(1-7). The cNOS enzymatic activity in thoracic spinal tissue was gradually decreased to a minimum at 72 h. Down-regulation of NOS by SP(1-7) in the thoracic area appears to be highly associated with capsaicin-sensitive primary afferent neurons. No similar changes in either parameter were measured in the lumbar area after SP(1-7). These data suggest that N-terminal SP fragments, which are known to cause long-term antinociception in the writhing assay, may do so by their ability to down-regulate NO synthesis along nociceptive pathways. [source]

Abnormal substance P release from the spinal cord following injury to primary sensory neurons

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2000
Marzia Malcangio
Abstract The neuropeptide substance P (SP) modulates nociceptive transmission within the spinal cord. Normally, SP is uniquely contained in a subpopulation of small-calibre axons (A,- and C-fibres) within primary afferent nerve. However, it has been shown that after nerve transection, besides being downregulated in small axons, SP is expressed de novo in large myelinated A,-fibres. In this study we investigated whether, following peripheral nerve injury, SP was released de novo from the spinal cord after selective activation of A,-fibres. Spinal cords with dorsal roots attached were isolated in vitro from rats 2 weeks following distal sciatic axotomy or proximal spinal nerve lesion (SNL). The ipsilateral dorsal roots were electrically stimulated for two consecutive periods at low- or high-threshold fibre strength, spinal cord superfusates were collected and SP content was determined by radioimmunoassay. SNL, but not axotomized or control rat cords, released significant amounts of SP after selective activation of A,-fibres. Not only do these data support the idea that A, myelinated fibres contribute to neuropathic pain by releasing SP, they also illustrate the importance of the proximity of the lesion to the cell body. [source]

New Monodentate P,C-Stereogenic Bicyclic Phosphanes: 1-Phenyl-1,3a,4,5,6,6a-hexahydrocyclopenta[b]phosphole and 1-Phenyloctahydrocyclopenta[b]phosphole

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2004
Zbigniew Pakulski
Abstract Racemic1-phenyl-1,3a,4,5,6,6a-hexahydrocyclopenta[b]phosphole (4) was separated into enantiomerically pure 1-phenyl-1,3a,4,5,6,6a-hexahydrocyclopenta[b]phosphole 1-oxides [(RP)- 6 and (SP)- 6] by an oxidative resolution procedure involving treatment of 4 with menthyl bromoacetate, crystallization of the resulting diastereoisomeric phosphonium bromides 8, and stereoselective hydrolysis of the diastereomerically pure salts to the corresponding enantiomerically pure phosphane oxides. Stereoretentive reduction of P=O in (RP)- 6 gave enantiomerically pure (SP)- 4. Hydrogenation of (SP)- 6 and subsequent reduction of P=O afforded saturated 1-phenyloctahydrocyclopenta[b]phosphole [(RP)- 5]. Monophosphanes (SP)- 4 and (RP)- 5 were tested as chiral ligands and catalysts in model asymmetric hydrogenation and C,C bond-forming reactions. Enantioselectivities of up to 95% were observed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

Personality, expectations, and response strategies in multiple-choice question examinations, in university students: a test of Gray's hypotheses

EUROPEAN JOURNAL OF PERSONALITY, Issue 1 2004
César Ávila
The relation between personality and type of error made in multiple-choice examinations when correction for guessing is applied was investigated across two studies. Our general hypothesis was that disinhibited subjects (those scoring high on the Sensitivity to Reward (SR) scale and/or low on the Sensitivity to Punishment (SP) scale) would make more incorrect responses and fewer omission errors (blanks) than inhibited subjects (those with high SP and/or low SR scores). The meta-analyses of 19 examinations in study 1 confirmed our hypotheses for SP, SR, and extraversion. Regression analyses on effect sizes revealed that SP differences were obtained in examinations with low marks, whereas SR differences were obtained in examinations with more responses and fewer questions. Study 2 showed that a low-mark expectation increased omissions in high-SP subjects, whereas a high-mark expectation increased incorrect responses in high-SR subjects. These results suggest two different mechanisms mediating inhibition/disinhibition: one associated with aversive motivation, and the other with appetitive motivation. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Delay analysis of a probabilistic priority discipline

EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 6 2002
Yuming Jiang
In computer networks, the Strict Priority (SP) discipline is perhaps the most common and simplest method to schedule packets from different classes of applications, each with diverse performance requirements. With this discipline, however, packets at higher priority levels can starve packets at lower priority levels. To resolve this starvation problem, we propose to assign a parameter to each priority queue in the SP discipline. The assigned parameter determines the probability or extent by which its corresponding queue is served when the queue is polled by the server. We thus form a new packet service discipline, referred to as the Probabilistic Priority (PP) discipline. By properly adjusting the assigned parameters, not only is the performance of higher priority classes satisfied, but also the performance of lower priority classes can be improved. This paper analyzes the delay performance of the PP discipline. A decomposition approach is proposed for calculating the average waiting times and their bounds are studied. Two approximation approaches are proposed to estimate the waiting times. Simulation results that validate the numerical analysis are presented and examined. A numerical example which demonstrates the use of the PP discipline to achieve service differentiation is presented. This example also shows how the assigned parameters can be determined from the results of analysis mentioned above. [source]

Foot shock stress prolongs the telogen stage of the spontaneous hair cycle in a non-depilated mouse model

EXPERIMENTAL DERMATOLOGY, Issue 7 2007
Mirei Katayama
Abstract:, Background:, There is an increasing evidence to indicate that stress can influence skin disease and cutaneous functions. Previous studies have shown that stress alters the murine hair cycle; however, these studies have been carried out by using mouse models in which the hair cycle is forcibly synchronized after depilation. Objective:, To examine whether foot shock stress (FS) changes the spontaneous hair cycle in a non-depilated animal model, and to evaluate the role of mast cells and substance P (SP) in the influence of stress on the hair cycle. Methods:, Changes in the spontaneous hair cycle and the inhibitory effects of a specific SP NK1 receptor antagonist were examined in non-depilated mice during 3,4 weeks of FS. Results:, Foot shock stress prolonged the telogen stage of the hair cycle and delayed the induction of the subsequent anagen stage in the animal model. FS caused an increase in the ratio of de-granulated mast cells in the skin, an increase in the number of TUNEL-positive cells, and a decrease in the number of Ki67-positive cells. The NK1 receptor antagonist, WIN 62577, inhibited these stress responses. Conclusion:, Our results strongly support previous work, demonstrating that stress alters active hair-cycling in vivo through the action of SP. [source]

Hair growth inhibition by psychoemotional stress: a mouse model for neural mechanisms in hair growth control

EXPERIMENTAL DERMATOLOGY, Issue 1 2006
Eva M. J. Peters
Abstract:, Stress has long been discussed controversially as a cause of hair loss. However, solid proof of stress-induced hair growth inhibition had long been missing. If psychoemotional stress can affect hair growth, this must be mediated via definable neurorendocrine and/or neuroimmunological signaling pathways. Revisiting and up-dating relevant background data on neural mechanisms of hair growth control, we sketch essentials of hair follicle (HF) neurobiology and discuss the modulation of murine hair growth by neuropeptides, neurotransmitters, neurotrophins, and mast cells. Exploiting an established mouse model for stress, we summarize recent evidence that sonic stress triggers a cascade of molecular events including plasticity of the peptidergic peri- and interfollicular innervation and neuroimmune crosstalk. Substance P (SP) and NGF (nerve growth factor) are recruited as key mediators of stress-induced hair growth-inhibitory effects. These effects include perifollicular neurogenic inflammation, HF keratinocyte apoptosis, inhibition of proliferation within the HF epithelium, and premature HF regression (catagen induction). Intriguingly, most of these effects can be abrogated by treatment of stressed mice with SP-receptor neurokinin-1 receptor (NK-1) antagonists or NGF-neutralizing antibodies , as well as, surprisingly, by topical minoxidil. Thus there is now solid in vivo -evidence for the existence of a defined brain- HF axis. This axis can be utilized by psychoemotional and other stressors to prematurely terminate hair growth. Stress-induced hair growth inhibition can therefore serve as a highly instructive model for exploring the brain-skin connection and provides a unique experimental model for dissecting general principles of skin neuroendocrinology and neuroimmunology well beyond the HF. [source]

Trafficking of neurokinin receptors: regulation, mechanism and function

EXPERIMENTAL DERMATOLOGY, Issue 9 2004
N. Bunnett
Cellular responses to agonists of G-protein-coupled receptors (GPCRs) depend in large part on the trafficking of receptors between the plasma membrane and intracellular locations. Receptor activation usually triggers rapid endocytosis of receptors, which either recycle to the cell surface or are targeted for degradation, depending on the receptor in question and the nature of the stimulation. Activation of neurokinin receptors (NKRs) induces membrane translocation of G-protein receptor kinases, which phosphorylate the receptors and ,-arrestins, which interact with phosphorylated receptors. ,-arrestins: 1) uncouple receptors from G-proteins to mediate desensitization; 2) are adaptors for clathrin and AP-2 and mediate clathrin and dynamin-dependent endocytosis of receptors; and 3) interact with components of the MAP kinase pathway such as src, and thereby determine the subcellular location and function of activated MAP kinases. The fate of endocytosed NKRs depends on the receptor and the nature of the stimulus. Transient stimulation with low concentrations of SP (1 nm, 10 min) induces rapid recycling of the NK1R from superficially located endosomes by a mechanism that is mediated by rab4a and rab11a. Higher concentrations of SP (10 nm) induce rab5a-dependent trafficking of the NK1R to perinuclear sorting endosomes and a gradual recycling to the plasma membrane. Continuous stimulation with high concentrations of SP (100 nm, 180 min) induces NK1R ubiquitination and trafficking for degradation. The fate of endocytosed receptors also depends on their interaction with ,-arrestins. The NK1R forms stable high-affinity interactions with both ,-arrestins 1 and 2 at the plasma membrane and in endosomes, whereas the NK3R interacts transiently only with ,-arrestin 2 at the cell surface. The nature of these interactions is specified by domains in the intracellular loop 3 and the carboxyl terminus and determine the rate of recycling and resensitization of these receptors. [source]

The role of neuropeptides and neuropeptide-degrading enzymes in wound healing

EXPERIMENTAL DERMATOLOGY, Issue 9 2004
John E. Olerud
Thirty to 40% of diabetic patients develop sensory neuropathy. Neuropathy is a major causal factor in diabetic ulcers. Only 31% of neuropathic diabetic ulcers heal in 20 weeks. Patients with neuropathy have a 15.5-fold excess risk of amputation. Diabetic patients with neuropathy particularly lose epidermal and papillary dermal sensory nerves which release neuropeptides such as substance P (SP). Neutral endopeptidase (NEP), the enzyme that degrades SP, is dramatically over expressed in patients with diabetic neuropathy. SP has positive effect on wound healing. Treatment strategies related to the nervous system for prevention and treatment of diabetic ulcers currently being studied include prevention of neuropathy with tight control of blood glucose, application of neuropeptides, nerve growth factors (NGF), and antagonists of NEP. [source]

Induction of neuropeptides in skin innervating sensory neurons by stress and nerve growth factor as a possible reason for hair growth alteration

EXPERIMENTAL DERMATOLOGY, Issue 9 2004
A. Kuhlmei
Recently, we introduced a mouse model launching experimental evidence for stress-induced hair growth inhibition (HGI), pointing to the existence of a brain-hair follicle axis (BFA). We suggested that nerve growth factor (NGF), besides neuropeptide substance P (SP), is a candidate mediator along the BFA. Published data further indicate that stress-related neuropeptides, e.g. calcitonin gene-related peptide (CGRP) and SP may be involved in HGI. SP and CGRP are synthesized in dorsal root ganglia (DRG) and released after axonal transport in the skin. Thus, aim of the present study was to investigate the effect of stress or subcutaneous injection of NGF, which mimics stress and regulates neuropeptide genes in sensory neurons, on the expression of SP and CGRP in DRG. Anagen was induced in C57BL/6 mice by depilation and retrograde tracing was employed on day 9 post-depilation (PD). On day 14 PD, mice were either exposed to sound stress (n = 4) injected subcutaneously with NGF (n = 4) or served as control (n = 4). On day 16 PD, DRG (mean of 30/mouse) were harvested and SP and CGRP in skin-specific sensory neurons, as identified by the tracer dye, were labelled by immunohistochemistry and counted. Stress exposure as well as NGF injection leads to a significant induction of SP and CGRP in retrograde-labelled neurons. This allows us to conclude that sensitive dermal nerve fibres are likely to originate from the presently identified neuropeptide-positive neurons. Peripheral activation of SP-expressing afferent nerve fibres via NGF-dependent pathways may cause neurogenic inflammation, eventually resulting in HGI. [source]

Predicting the J integral fracture toughness of Al 6061 using the small punch test

FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 9 2007
E. BUDZAKOSKA
ABSTRACT The 6000 series aluminium alloys (Al,Mg,Si systems) are commonly used as medium-strength structural materials; in particular, the 6061 (Al,1Mg,0.6Si) alloy is widely utilized as a general-purpose structural material due to its excellent formability and corrosion-resisting capabilities. The objective of this study was to obtain a correlation between the small punch (SP) test estimated equivalent fracture strain (,qf) and fracture toughness (J1C) property for 6061 aluminium, and determine its viability as a non-destructive fracture toughness test technique for remaining life assessment of in-service components. Samples of 6061-T6 aluminium were cut from bulk plate, in both the longitudinal and transverse directions, for the as-received condition as well as subjected to three different over-ageing heat-treatment schedules. A strong linear correlation between valid J1C and SP estimated biaxial fracture strain ,qf is presented for aluminium 6061 at room temperature. [source]

An active triple-catalytic hybrid enzyme engineered by linking cyclo-oxygenase isoform-1 to prostacyclin synthase that can constantly biosynthesize prostacyclin, the vascular protector

FEBS JOURNAL, Issue 23 2008
Ke-He Ruan
It remains a challenge to achieve the stable and long-term expression (in human cell lines) of a previously engineered hybrid enzyme [triple-catalytic (Trip-cat) enzyme-2; Ruan KH, Deng H & So SP (2006) Biochemistry45, 14003,14011], which links cyclo-oxygenase isoform-2 (COX-2) to prostacyclin (PGI2) synthase (PGIS) for the direct conversion of arachidonic acid into PGI2 through the enzyme's Trip-cat functions. The stable upregulation of the biosynthesis of the vascular protector, PGI2, in cells is an ideal model for the prevention and treatment of thromboxane A2 (TXA2)-mediated thrombosis and vasoconstriction, both of which cause stroke, myocardial infarction, and hypertension. Here, we report another case of engineering of the Trip-cat enzyme, in which human cyclo-oxygenase isoform-1, which has a different C-terminal sequence from COX-2, was linked to PGI2 synthase and called Trip-cat enzyme-1. Transient expression of recombinant Trip-cat enzyme-1 in HEK293 cells led to 3,5-fold higher expression capacity and better PGI2 -synthesizing activity as compared to that of the previously engineered Trip-cat enzyme-2. Furthermore, an HEK293 cell line that can stably express the active new Trip-cat enzyme-1 and constantly synthesize the bioactive PGI2 was established by a screening approach. In addition, the stable HEK293 cell line, with constant production of PGI2, revealed strong antiplatelet aggregation properties through its unique dual functions (increasing PGI2 production while decreasing TXA2 production) in TXA2 synthase-rich plasma. This study has optimized engineering of the active Trip-cat enzyme, allowing it to become the first to stably upregulate PGI2 biosynthesis in a human cell line, which provides a basis for developing a PGI2 -producing therapeutic cell line for use against vascular diseases. [source]

Co-operative effect of the isoforms of type III antifreeze protein expressed in Notched-fin eelpout, Zoarces elongatus Kner

FEBS JOURNAL, Issue 2 2005
Yoshiyuki Nishimiya
We found that Notched-fin eelpout, which lives off the north east coast of Japan, expresses an antifreeze protein (AFP). The liver of this fish contains DNAs that encode at least 13 type III AFP isoforms (denoted nfeAFPs). The primary sequences of the nfeAFP isoforms were categorized into SP- and QAE-sephadex binding groups, and the latter were further divided into two subgroups, QAE1 and QAE2 groups. Ice crystals observed in HPLC-pure nfeAFP fractions are bipyramidal in shape with different ratios of c and a axes, suggesting that all the isoforms are able to bind ice. We expressed five recombinant isoforms of nfeAFP and analyzed the thermal hysteresis (TH) activity of each as a function of protein concentration. We also examined the change in activity on mixing the isoforms. TH was estimated to be 0.60 °C for the QAE1 isoform, 0.11 °C for QAE2, and almost zero for the SP isoforms when the concentrations of these isoforms was standardized to 1.0 mm. Significantly, the TH activity of the SP isoforms showed concentration dependence in the presence of 0.2 mm QAE1, indicating that the less active SP isoform becomes ,active' when a small amount of QAE1 is added. In contrast, it does not become active on the addition of another SP isoform. These results suggest that the SP and QAE isoforms of type III AFP have different levels of TH activity, and they accomplish the antifreeze function in a co-operative manner. [source]

Domain V of m-calpain shows the potential to form an oblique-orientated ,-helix, which may modulate the enzyme's activity via interactions with anionic lipid

FEBS JOURNAL, Issue 22 2002
Klaus Brandenburg
The activity of m-calpain, a heterodimeric, Ca2+ -dependent cysteine protease appears to be modulated by membrane interactions involving oblique-orientated ,-helix formation by a segment, GTAMRILGGVI, in the protein's smaller subunit. Here, graphical and hydrophobic moment-based analyses predicted that this segment may form an ,-helix with strong structural resemblance to the influenza virus peptide, HA2, a known oblique-orientated ,-helix former. Fourier transform infrared spectroscopy showed that a peptide homologue of the GTAMRILGGVI segment, VP1, adopted low levels of ,-helical structure (, 20%) in the presence of zwitterionic lipid and induced a minor decrease (3 °C) in the gel to liquid-crystalline phase transition temperature, TC, of the hydrocarbon chains of zwitterionic membranes, suggesting interaction with the lipid headgroup region. In contrast, VP1 adopted high levels of ,-helical structure (65%) in the presence of anionic lipid, induced a large increase (10 °C) in the TC of anionic membranes, and showed high levels of anionic lipid monolayer penetration (,SP = 5.5 mN·m,1), suggesting deep levels of membrane penetration. VP1 showed strong haemolytic ability (LD50 = 1.45 mm), but in the presence of ionic agents, this ability, and that of VP1 to penetrate anionic lipid monolayers, was greatly reduced. In combination, our results suggest that m-calpain domain V may penetrate membranes via the adoption of an oblique-orientated ,-helix and electrostatic interactions. We speculate that these interactions may involve snorkelling by an arginine residue located in the polar face of this ,-helix. [source]

High Quality Factor Metallodielectric Hybrid Plasmonic,Photonic Crystals

ADVANCED FUNCTIONAL MATERIALS, Issue 12 2010
Xindi Yu
Abstract A 2D polystyrene colloidal crystal self-assembled on a flat gold surface supports multiple photonic and plasmonic propagating resonance modes. For both classes of modes, the quality factors can exceed 100, higher than the quality factor of surface plasmons (SP) at a polymer,gold interface. The spatial energy distribution of those resonance modes are carefully studied by measuring the optical response of the hybrid plasmonic,photonic crystal after coating with dielectric materials under different coating profiles. Computer simulations with results closely matching those of experiments provide a clear picture of the field distribution of each resonance mode. For the SP modes, there is strong confinement of electromagnetic energy near the metal surface, while for optical modes, the field is confined inside the spherical particles, far away from the metal. Coating of dielectric material on the crystal results in a large shift in optical features. A surface sensor based on the hybrid plasmonic,photonic crystal is proposed, and it is shown to have atomic layer sensitivity. An example of ethanol vapor sensing based on physisorption of ethanol onto the sensor surface is demonstrated. [source]