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Contradictory Reports (contradictory + report)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Spatiotemporal analysis of NO production upon NMDA and tetanic stimulation of the hippocampus

HIPPOCAMPUS, Issue 4 2005
Norio Takata
Abstract Nitric oxide (NO) is a gaseous neuromessenger. Although increasing evidence reveals significant physiological effects of NO in the hippocampal synaptic plasticity, the spatial distribution of NO production has remained largely uncharacterized due to the poor development of techniques for real-time NO imaging. In this work, using a NO-reactive fluorescent dye, diaminorhodamine-4M (DAR-4M), time-dependent heterogeneous NO production is demonstrated in hippocampal slices upon N-methyl- D -aspartate (NMDA) stimulation or tetanic stimulation. NMDA-induced DAR fluorescence increase in the CA1 was found to be twice that in the CA3 and the dentate gyrus (DG). Intracellular Ca2+ concentration was also investigated. NMDA induced similar Ca2+ responses both in the CA1 and DG, which were approx. 13% greater than that in the CA3. Subsequently, spatial distribution of NO production in the CA1 upon a tetanic stimulation of Schaffer collateral was investigated, because there are contradictory reports on the effect of NO on long-term potentiation (LTP), and that NO is known to exert various physiological effects depending on its concentration. In the stratum radiatum (sr), DAR fluorescence increase upon tetanus was largest at the vicinity of a stimulating electrode and decreased as a function of increasing distance from the stimulating electrode, suggesting the possibility that the effect of NO in LTP is dependent on the distance between stimulating and recording electrodes. The tetanus-induced Ca2+ response observed in the sr showed the same but weak distant dependence from the stimulating electrode. Taken together, the observed heterogeneity in the distribution of NO production is suggestive of region-specific effects of NO in the hippocampus. © 2005 Wiley-Liss, Inc. [source]

Drought and salinity: A comparison of their effects on mineral nutrition of plants

JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 4 2005
Yuncai Hu
Abstract The increasing frequency of dry periods in many regions of the world and the problems associated with salinity in irrigated areas frequently result in the consecutive occurrence of drought and salinity on cultivated land. Currently, 50% of all irrigation schemes are affected by salinity. Nutrient disturbances under both drought and salinity reduce plant growth by affecting the availability, transport, and partitioning of nutrients. However, drought and salinity can differentially affect the mineral nutrition of plants. Salinity may cause nutrient deficiencies or imbalances, due to the competition of Na+ and Cl, with nutrients such as K+, Ca2+, and NO. Drought, on the other hand, can affect nutrient uptake and impair acropetal translocation of some nutrients. Despite contradictory reports on the effects of nutrient supply on plant growth under saline or drought conditions, it is generally accepted that an increased nutrient supply will not improve plant growth when the nutrient is already present in sufficient amounts in the soil and when the drought or salt stress is severe. A better understanding of the role of mineral nutrients in plant resistance to drought and salinity will contribute to an improved fertilizer management in arid and semi-arid areas and in regions suffering from temporary drought. This paper reviews the current state of knowledge on plant nutrition under drought and salinity conditions. Specific topics include: (1) the effects of drought and salt stress on nutrient availability, uptake, transport, and accumulation in plants, (2) the interactions between nutrient supply and drought- or salt-stress response, and (3) means to increase nutrient availability under drought and salinity by breeding and molecular approaches. Trockenstress und Salzstress , Vergleich der Auswirkungen auf die mineralische Ernährung von Pflanzen Eine Zunahme von Trockenperioden in vielen Ländern der Welt und assoziierte Probleme der Versalzung in bewässerten Gebieten führen häufig zu gleichzeitigem Auftreten von Trockenheit und Salinität. Gegenwärtig sind weltweit ungefähr 50 % aller Bewässerungsflächen durch Salinität beeinträchtigt. Nährstoffstörungen bei Trocken- und Salzstress beeinträchtigen die Verfügbarkeit, den Transport und die Verteilung von Nährelementen in der Pflanze und reduzieren somit das Pflanzenwachstum. Trocken- und Salzstress können sich jedoch unterschiedlich auf die Nährstoffversorgung der Pflanzen auswirken. Salinität kann aufgrund der Konkurrenz zwischen Na+ bzw. Cl, und Nährelementen wie K+, Ca2+ und NO Nährstoffmängel oder -ungleichgewichte in den Pflanzen verursachen. Trockenstress kann sowohl die Nährstoffaufnahme als auch den akropetalen Transport einiger Elemente beeinträchtigen. Trotz kontroverser Schlussfolgerungen in der Literatur hinsichtlich der Wechselbeziehungen von Nährstoffangebot und Trocken- bzw. Salzstress auf das Pflanzenwachstum ist allgemein akzeptiert, dass Nährstoffzufuhr das Pflanzenwachstum nicht verbessert, wenn ausreichend Nährstoffe im Boden verfügbar sind oder bei stark ausgeprägter Trockenheit oder Salinität. Ein besseres Verständnis der Rolle von Mineralstoffen in der Toleranz von Pflanzen gegenüber Trocken- oder Salzstress dürfte gerade in ariden und semi-ariden Gebieten sowie in Regionen, die unter periodischer Trockenheit leiden, zu verbesserten Düngestrategien beitragen. In der vorliegenden Arbeit wird der gegenwärtige Kenntnisstand der mineralischen Ernährung bei Trockenheit und Salinität diskutiert. Schwerpunkte der Betrachtungen sind (1) die Auswirkungen von Trockenheit und Salzstress auf die Verfügbarkeit, die Aufnahme, den Transport und die Anreicherung von Nährelementen in der Pflanze, (2) Wechselbeziehungen zwischen dem Nährstoffangebot und Trockenheit oder Salinität sowie (3) Maßnahmen zur Verbesserung der Nährstoffverfügbarkeit bei Trockenheit und Salzstress mittels züchterischer und molekularbiologischer Ansätze. [source]

The Effectiveness of Psychological Interventions for the Treatment of Erectile Dysfunction: Systematic Review and Meta-Analysis, Including Comparisons to Sildenafil Treatment, Intracavernosal Injection, and Vacuum Devices

THE JOURNAL OF SEXUAL MEDICINE, Issue 11 2008
Tamara Melnik PhD
ABSTRACT Introduction., In contrast to the impressive advances in somatic research of erectile dysfunction (ED), scientific literature shows contradictory reports on the results of psychotherapy for the treatment of ED. Aim., Authors conducted a meta-analysis to evaluate the effectiveness of psychological interventions for the treatment of ED compared to oral drugs, local injection, vacuum devices, or other psychological intervention. Method., Distinct sources of randomized controlled trials (RCTs) were searched: electronic databases (between 1966 and 2007), cross checking of references, and contact with scientific societies. Main Outcome Measures., For dichotomous outcomes the pooled relative risks were calculated and for continuous outcomes mean differences between interventions. Statistical heterogeneity was addressed. Results., Eleven RCTs involving 398 men met the inclusion criteria. Conclusions., There is evidence that group therapy improves ED. Focused sex group therapy showed greater efficacy than control group. Men randomized to receive psychotherapy plus sildenafil showed significant improvement of ED and were less likely than those receiving only sildenafil to drop out. Regarding to the effectiveness of psychological interventions for the treatment of ED compared to local injection and vacuum devices no difference was found. Melnik T, Soares BGO, and Nasello AG. The effectiveness of psychological interventions for the treatment of erectile dysfunction: Systematic review and meta-analysis, including comparisons to sildenafil treatment, intracavernosal injection, and vacuum devices. J Sex Med 2008;5:2562,2574. [source]

Morton's design of the early ether vaporisers

ANAESTHESIA, Issue 5 2002
P. Desbarax
Summary The exact design of the ether vaporiser used by William Morton on 16 October 1846 has remained uncertain with many contradictory reports. This article explores the known facts and speculates on the design used on that and subsequent occasions. [source]