bluuebunny/crossref_metadata_2025_split huggingface dataset:
RNAi– induced silencing of the plasma membrane Ca2+– ATPase 2 in neuronal cells: effects on Ca2+ homeostasis and cell viability
Authors: Fernandes Denzyl , Zaidi Asma , Bean Jennifer , Hui Dongwei , Michaelis Mary L. 
Published: May 2007

AbstractIntraneuronal calcium ([Ca2+]i) regulation is altered in aging brain, possibly because of the changes in critical Ca2+ transporters. We previously reported that the levels of the plasma membrane Ca2+‐ATPase (PMCA) and the Vmax for enzyme activity are significantly reduced in synaptic membranes in aging rat brain. The goal of these studies was to use RNAi techniques to suppress expression of a major neuronal isoform, PMCA2, in neurons in culture to determine the potential functional consequences of a decrease in PMCA activity. Embryonic rat brain neurons and SH‐SY5Y neuroblastoma cells were transfected with in vitro– transcribed short interfering RNA or a short hairpin RNA expressing vector, respectively, leading to 80% suppression of PMCA2 expression within 48 h. Fluorescence ratio imaging of free [Ca2+]i revealed that primary neurons with reduced PMCA2 expression had higher basal [Ca2+]i, slower recovery from KCl‐induced Ca2+ transients, and incomplete return to pre‐stimulation Ca2+ levels. Primary neurons and SH‐SY5Y cells with PMCA2 suppression both exhibited significantly greater vulnerability to the toxicity of various stresses. Our results indicate that a loss of PMCA such as occurs in aging brain likely leads to subtle disruptions in normal Ca2+ signaling and enhanced susceptibility to stresses that can alter the regulation of Ca2+ homeostasis.
Paradoxical modulation of short‐term facilitation of dopamine release by dopamine autoreceptors
Authors: Kita Justin M. , Parker Lauren E. , Phillips Paul E. M. , Garris Paul A. , Wightman R. Mark 
Published: May 2007

AbstractElectrophysiological studies have demonstrated that dopaminergic neurons burst fire during certain aspects of reward‐related behavior; however, the correlation between dopamine release and cell firing is unclear. When complex stimulation patterns that mimic intracranial self‐stimulation were employed, dopamine release was shown to exhibit facilitated as well as depressive components (Montague et al. 2004). Understanding the biological mechanisms underlying these variations in dopamine release is necessary to unravel the correlation between unit activity and neurotransmitter release. The dopamine autoreceptor provides negative feedback to dopamine release, inhibiting release on the time scale of a few seconds. Therefore, we investigated this D2 receptor to see whether it is one of the biological mechanisms responsible for the history‐dependent modulation of dopamine release. Striatal dopamine release in anesthetized rats was evoked with stimulus trains that were designed to promote the variability of dopamine release. Consistent with the well established D2‐mediated autoinhibition, the short‐term depressive component of dopamine release was blocked by raclopride, a D2 antagonist, and enhanced by quinpirole, a D2‐receptor agonist. Surprisingly, these same drugs exerted a similar effect on the short‐term facilitated component: a decrease with raclopride and an increase with quinpirole. These data demonstrate that the commanding control exerted by dopamine autoreceptors over short‐term neuroadaptation of dopamine release involves both inhibitory and paradoxically, facilitatory components.
Regulation of PI3K/Akt/GSK‐3 pathway by cannabinoids in the brain
Authors: Ozaita Andrés , Puighermanal Emma , Maldonado Rafael 
Published: May 2007

AbstractDelta9‐tetrahydrocannabinol (THC), the main psychoactive component in Cannabis sativa preparations, exerts its central effects mainly through the G‐protein coupled receptor CB1, a component of the endocannabinoid system. Several in vitro and in vivo studies have reported neuroprotective effects of cannabinoids in excitotoxicity and neurodegeneration models. However, the intraneuronal signaling pathways activated in vivo by THC underlying its central effects remain poorly understood. We report that THC acute administration (10 mg/kg, i.p.) increases the phosphorylation of Akt in mouse hippocampus, striatum, and cerebellum. This phosphorylation was mediated by CB1 receptors as it was blocked by the selective CB1 antagonist rimonabant. Moreover, PI3K inhibition by wortmannin abrogated THC‐induced phosphorylation of Akt, but blockade of extracellular signal‐regulated protein kinases by SL327 did not modify this activation/phosphorylation of Akt. Moreover, administration of the dopaminergic D1 (SCH 23390) and D2 (raclopride) receptor antagonists did not block the activation of PI3K/Akt pathway induced in the striatum by cannabinoid receptor stimulation, suggesting that this effect is independent of the dopaminergic system. In addition, THC increased the phosphorylation of glycogen synthase kinase 3 beta. Therefore, activation of the PI3K/Akt/GSK‐3 signaling pathway may be related to the in vivo neuroprotective properties attributed to cannabinoids.
Effects of sleep deprivation on anaerobic exercise‐induced changes in auditory brainstem evoked potentials
Authors: Öztürk Levent , Bulut Erdoğan , Vardar Selma Arzu , Uzun Cem 
Published: May 2007

SummaryBackground  The present study was designed to assess how anaerobic exercise affects auditory brainstem response (ABR) parameters, and whether one night of sleep deprivation could alter these possible exercise‐induced changes in ABRs.Methods  Seven healthy, audiologically normal male students (mean age 22·4 ± 1·0 years) participated in the study. All subjects underwent anaerobic Wingate test for three times: (i) baseline, (ii) following a full‐night of habitual sleep and (iii) following one night of sleep deprivation. ABR measurements were performed before and after the second and the third Wingate tests. Oral body temperatures were recorded at the beginning of all ABR measurements.Results  The latencies of wave III and V significantly shortened by anaerobic loading performed in the day after habitual sleep (4·13 ± 0·10 versus 4·01 ± 0·17 ms, P<0·02; and 5·84 ± 0·26 versus 5·65 ± 0·23 ms, P<0·03, respectively). One night of total sleep deprivation shortened pre‐exercise latencies and altered exercise‐induced changes in ABRs.Conclusion  The findings obtained in the present study show that acute anaerobic exercise is effective on ABR wave latencies independent from body temperature changes, and sleep deprivation has some modulatory effects on exercise‐induced changes in ABR.
Comparison between aortic, mitral and tricuspid annular velocities measured with quantitative two‐dimensional color Doppler tissue imaging in healthy subjects
Authors: Emilsson K. , Egerlid R. , Magnuson A. , Nygren B. M. 
Published: May 2007

SummaryObjectives  To compare the systolic, early and late diastolic velocities of the aortic, mitral and tricuspid annuli in healthy subjects and to study the intraobserver and interobserver reproducibility (IIOR) of measuring the velocities at the aortic annulus.Methods  Twenty healthy subjects with mean age 28 years were investigated with quantitative two‐dimensional color Doppler tissue imaging and the systolic, early and late diastolic velocities were measured at the aortic, mitral and tricuspid annuli.Results  The mitral annulus had significant higher systolic velocity and early diastolic velocity than the aortic annulus. The late diastolic velocity was significant lower at the aortic annulus compared with the both other annuli.At the different sites of the annuli the highest systolic velocity and early diastolic velocity were measured at the lateral site of the mitral annulus, whereas the lowest systolic velocity was measured at the septal site of the same annulus. The lowest early diastolic velocity was found at the septal site of the aortic annulus.The highest late diastolic velocity was measured at the lateral site of the tricuspid annulus and the lowest at the lateral site of the aortic annulus.Conclusions  The mitral annulus has statistical significant higher systolic and early diastolic velocities than the aortic annulus. There are significant differences in velocities between several of the different sites of the annuli. IIOR of measuring the systolic and early diastolic velocities of the aortic annulus is good.
The Role of the United Nations in the Independence of Namibia
Authors: Saunders Christopher 
Published: May 2007

AbstractWhen South African rule ended and Namibia finally gained its independence on 21 March 1990 it was the United Nations (UN) Secretary‐General Pérez de Cuellar who presided at the ceremony in Windhoek, the capital, and who swore in Sam Nujoma as the first President of the independent state. This symbolically recognised the fact that the UN had played a major role in aiding the process leading to independence. But that role was very different from the one which the UN had wanted to play decades before. This article explains why the UN's role was more limited than originally conceived, and assesses what the UN did to help achieve Namibia's independence.
Seroprevalence of Helicobacter pylori Infection Among Schoolchildren and Teachers in Taiwan
Authors: Lin Ding‐Bang , Lin Jye‐Bin , Chen Chien‐Yi , Chen Shiuan‐Chih , Chen Wen‐Kang 
Published: May 2007

AbstractBackground:  Helicobacter pylori are associated with chronic antral gastritis that is related to duodenal ulcer, gastric ulcer, and probably gastric adenocarcinoma. Infection of H. pylori during childhood is considered an important risk factor for gastric carcinoma in adult life.Materials and Methods:  To examine the epidemiologic characteristics of H. pylori infection among schoolchildren in central Taiwan, a community‐based survey was carried out using stratified sampling in 10 elementary schools and three junior high schools including students and theirs teachers. Serum specimens of 1950 healthy schoolchildren (aged 9–15 years old) and 253 teachers who were randomly sampled were screened for the H. pylori antibodies by enzyme‐linked immunosorbent assay. Statistical analysis was performed by using the spss for Windows statistical software system.Results:  A total of 332 subjects were H. pylori antibodies positive, giving an overall prevalence of 15.1%. The age‐specific seropositive rates were 11.0% in 9–12 years age group, 12.3% in 13–15 years age group, and 45.1% in the teacher group. The older the age, the higher the seroprevalence (OR = 11.53; 95% CI = 6.73–19.74; p < .001 for children vs. teachers). There was no difference in the seroprevalence of H. pylori infection by gender, ethnicity, geographical area, socioeconomic level, parental education, sibship size, family members, and source of drinking water.Conclusion:  The teachers had a much higher prevalence of H. pylori antibodies. The finding suggests that these teachers (adults) might be infected in their early childhood and implies that the poor environmental and hygienic conditions might be responsible for it. It seemed that poor water supply system, sewage disposal, and other environmental hygiene in adult might play some roles in H. pylori infection in Taiwan (before early 1980s).
The Relationship of Helicobacter pylori Positivity with Age, Sex, and ABO/Rhesus Blood Groups in Patients with Gastrointestinal Complaints in Turkey
Authors: Şeyda Türkölmez , Derya Çayır , Füsun Aydoğan , Meliha Korkmaz 
Published: May 2007

AbstractBackground:  To determine the magnitude of Helicobacter pylori infection in patients with gastrointestinal complaints in Turkey.Methods: We studied 1680 patients with variable gastrointestinal complaints. The H. pylori infection status was determined using C‐14 urea breath test (UBT). Overall, 1567 patients (548 male, 1019 female; age range 4–80 years, mean 29.37 ± 17.30 years) were included in this study. The relationship between H. pylori positivity and age, sex, sociodemographic characteristic, blood groups, and gastrointestinal diagnosis was determined.Results: H. pylori positivity was found to be 68%. The difference in positivity rates between age groups 4–9 years and other groups was statistically significant (p = .001). H. pylori positivity was 67.7% in males and 68.2% in females (p = .865). H. pylori positivity was 72.1, 65.1, 70, and 68.4% in blood groups A, B, AB, and O (p = .703), and 68.9% and 76.3% in Rh (+) and Rh (–) blood subgroups, respectively (p = .292). There was no statistically significant difference between H. pylori positivity and gastrointestinal diagnosis (p = .980). There was significant association between increased number of household members and low socioeconomic status, and H. pylori positivity (p < .001). Living in rural and suburban area was significantly associated with H. pylori positivity compared with living in urban.Conclusions: H. pylori infection positivity rate was 68% in symptomatic subjects in Turkey and the positivity rate was significantly lower at age 4–9 years than the other age groups. It was not related to gender, ABO, and Rh blood groups and gastrointestinal diagnosis. Low socioeconomic conditions and living in rural and suburban area were significantly associated with H. pylori positivity.
Helicobacter pylori Infection as a Triggering Factor of Attacks in Patients with Hereditary Angioedema
Authors: Visy Beáta , Füst George , Bygum Anette , Bork Konrad , Longhurst Hilary , Bucher Christoph , Bouillet Laurence , Cicardi Marco , Farkas Henriette 
Published: May 2007

AbstractBackground:  Helicobacter pylori infection is considered among the causative factors of urticaria and angioedema. Having conducted a study on 65 patients, Hungarian authors reported in 2001 that successful eradication of H. pylori is followed by a significant reduction in the number of attacks in patients with hereditary angioedema (HAE). The present study aimed to reinvestigate the relationship between H. pylori infection and the attack rate in the framework of an international collaborative study.Materials and methods:  Within the framework of the PREHAEAT project launched by the European Union, further 152 patients were studied in seven collaborating centers, and participants of the earlier study were followed up in order to detect any relationship between H. pylori infection and the occurrence of attacks in patients suffered from HAE.Results:  The proportion of patients experiencing frequent (≥ 5 per year) abdominal attacks was higher (p = .002) among the H. pylori‐infected participants of the international study who underwent eradication as compared to the rest of patients. Successful eradication of H. pylori significantly (p = .0006) reduced the number of attacks in these patients as well.Nine subjects of the previous Hungarian study who underwent eradication therapy for dyspepsia were followed up for an additional 4 years. In these patients, attack frequency remained consistently low.Conclusions:  As shown by experience from the Hungarian and the international trial, the number of frequent, edematous abdominal attacks may decrease substantially following the eradication of H. pylori from HAE patients infected with this pathogen. Therefore, screening of patients with HAE for H. pylori infection seems warranted. Eradication of H. pylori may lead to a marked reduction in disease severity.
HP/LT metamorphism in the Volparone Breccia (Northern Corsica, France): evidence for involvement of the Europe/Corsica continental margin in the Alpine subdution zone
Authors: MALASOMA A. , MARRONI M. 
Published: May 2007

AbstractThe Alpine belt in Corsica (France) is characterized by the occurrence of stacked tectonic slices derived from the Corsica/Europe continental margin, which outcrop between two weakly or non‐metamorphic tectonic domains: the ‘autochthonous’ domain of the Hercynian basement to the west and the Balagne Nappe (ophiolitic unit belonging to the ‘Nappes supérieures’) to the east. These slices, including basement rocks (Permian granitoids and their Palaeozoic host rocks), Late Carboniferous–Permian volcano‐sedimentary deposits, coarse‐grained polymict breccias (Volparone Breccia) and Middle Eocene siliciclastic turbidite deposits, were affected by a polyphase deformation history of Alpine age, associated with a well‐developed metamorphic recrystallization. This study provides new quantitative data about the peak of metamorphism and the retrograde P–T path in the Alpine Corsica: the tectonic slices of Volparone Breccia from the Balagne region (previously regarded as unmetamorphosed) were affected by peak metamorphism characterized by the phengite + chlorite + quartz ± albite assemblage. Using the chlorite‐phengite local equilibria method, peak metamorphic P–T conditions coherent with the low‐grade blueschist facies are estimated as 0.60 ± 0.15 GPa and 325 ± 20 °C. Moreover, the retrograde P–T path, characterized by a decrease of pressure and temperature, is evidence of the first stage of the exhumation path from the peak metamorphic conditions to greenschist facies conditions (0.35 ± 0.06 GPa and 315 ± 20 °C). The occurrence of metamorphic peak at high‐pressure/low‐temperature (HP/LT) conditions is evidence of the fact that these tectonic slices, derived from the Corsica/Europe continental margin, were deformed and metamorphosed in the Alpine subduction zone during their underplating at ∼20 km of depth into the accretionary wedge and were subsequently juxtaposed against the metamorphic and non‐metamorphic oceanic units during a complex exhumation history.
Brain Activation Elicited by Affectively Positive Stimuli Is Associated With a Lower Risk of Relapse in Detoxified Alcoholic Subjects
Authors: Heinz Andreas , Wrase Jana , Kahnt Thorsten , Beck Anne , Bromand Zohra , Grüsser Sabine M. , Kienast Thorsten , Smolka Michael N. , Flor Herta , Mann Karl 
Published: May 2007

Background: Stimuli that are regularly associated with alcohol intake (AI) may acquire incentive salience, while other reinforcers can be devalued. We assessed whether brain activation elicited by (1) alcohol associated, (2) affectively positive, and (3) negative versus neutral stimuli is associated with the subsequent risk of relapse.Methods: Twelve detoxified alcoholic subjects (6 women and 6 men) and 12 age‐matched and gender‐matched healthy control subjects were assessed with functional magnetic resonance imaging (fMRI) and a fast single‐event paradigm using standardized affective and alcohol‐associated pictures. Patients were followed for 6 months and AI was recorded.Results: In alcoholic subjects, compared with healthy control subjects, (1) alcohol‐related versus neutral visual stimuli elicited increased activation in the prefrontal (PFC; BA 6 and 10) and cingulate cortex (BA 23 and 24), precuneus and adjacent parietal cortex; (2) positive versus neutral stimuli elicited increased activation in the anterior cingulate cortex (ACC; BA 24), PFC (BA 10), ventral striatum and thalamus; and (3) negative versus neutral stimuli elicited increased activation in the PFC (BA 10). Seven alcoholic subjects relapsed. Within the follow‐up period of 6 months, the number of subsequent drinking days (DD) and the amount of AI were inversely correlated with brain activation elicited by positive versus neutral stimuli in the thalamus (DD: r=−0.63, p=0.03; AI: r=−0.63, p=0.03) and in the ventral striatum (DD: r=−0.60, p=0.04; AI: r=−0.48, p=0.11).Conclusions: In this study, brain activation elicited by briefly presented alcohol‐associated stimuli was not associated with the prospective risk of relapse. Unexpectedly, alcoholic subjects displayed increased limbic brain activation during the presentation of affectively positive but not negative stimuli, which may reflect a protective factor in detoxified alcoholic subjects.
Hollywood Must Portray Point of View of Others
Authors: IÑÁRRITU ALEJANDRO GONZÁLEZ 
Published: May 2007

In the age of globalization we are no longer home alone. Migration brings other worlds into our own just as the global reach of the mass media transmits our world into the hearts and minds of others. The resulting clashes and fusions are shaping the soul of the first global civilization in the making.In this section, one of Hollywood's top producers, Mike Medavoy, and the Oscar‐nominated director of Babel, Alejandro González Iñárritu share their thoughts with NPQ.
Giving Content to Investor Sentiment: The Role of Media in the Stock Market
Authors: TETLOCK PAUL C. 
Published: May 2007

ABSTRACTI quantitatively measure the interactions between the media and the stock market using daily content from a popular Wall Street Journal column. I find that high media pessimism predicts downward pressure on market prices followed by a reversion to fundamentals, and unusually high or low pessimism predicts high market trading volume. These and similar results are consistent with theoretical models of noise and liquidity traders, and are inconsistent with theories of media content as a proxy for new information about fundamental asset values, as a proxy for market volatility, or as a sideshow with no relationship to asset markets.
Effects on poverty and equity of the decline in collective tank irrigation management in Tamil Nadu, India
Authors: Kajisa Kei , Palanisami K. , Sakurai Takeshi 
Published: May 2007

AbstractThis paper investigates the factors influencing the decline in collective management of local commons and the impact of this decline on agricultural production and household consumption. The analysis is based on a village and household data set collected in 1999 in Tamil Nadu, India, where tank irrigation systems are managed collectively for rice cultivation by informal water users' organizations. Our statistical analyses find that one major reason for the decline in collective tank irrigation management is the dissemination of private well irrigation systems. Once the decline has occurred, our analyses predict that the gap in rice yields between farmers who have access to private wells and those who must rely solely on tanks will widen, with only the latter group suffering lower yields. Our analyses also find that the same pattern holds for levels of income and consumption because the affected farmers cannot sufficiently compensate for the loss of their rice income by diversifying their income sources to agricultural labor or nonagricultural work. In this way, the decline in collective management results in greater inequality and poverty.
Economic development and the role of agricultural technology
Authors: Self Sharmistha , Grabowski Richard 
Published: May 2007

AbstractIn earlier debates on economic development, the agricultural sector's role was somewhat controversial. While dualistic models highlighted the importance of agriculture, the mainstream literature placed a greater emphasis on the creation of a modern industrial sector. Soon agriculture disappeared from the mainstream development literature to re‐emerge recently with a variety of multiple‐sector growth models emphasizing the key role of agriculture and specifically technology in agriculture. This article is an empirical cross‐country analysis of agricultural technology's role in economic development. Specifically, the hypothesis being tested is whether improvements in agricultural technology have a significant impact on long‐run economic growth. The results indicate that agricultural modernization has a positive effect on both measures of economic growth and human development.