Inhibition of nitric oxide synthesis extends cerebrovascular autoregulation during hypertension

In anesthetized intact rats, cerebral blood flow is autoregulated until mean arterial blood pressure (MAP) exceeds 150 mmHg. At higher pressures cerebral blood flow breaks through autoregulation and rapidly increases. However, interruption of the arterial baroreceptor reflex eliminates breakthrough of autoregulation. Thus, breakthrough may reflect active rather than passive vasodilatation. We, therefore, sought to determine if breakthrough depends upon synthesis of the vasodilator nitric oxide. Thirty-eight anesthetized adult male Sprague-Dawley rats were studied. In all, MAP was raised by slow i.v. infusion of phenylephrine. In rats pretreated with the nitric oxide synthase inhibitor L-nitroarginine (L-NA; 22 mg/kg i.v.) or with a combination of L-NA plus D-arginine (D-Arg; 240 mg/kg i.v.), breakthrough did not occur even when MAP exceeded 185 mmHg (L-NA) and 165 mmHg (D-Arg). In contrast, breakthrough occurred in rats treated with L-NA plus L-arginine (L-Arg; 240 mg/kg i.v.) and in rats whose basal vascular tone had been increased by pretreatment with arginine vasopressin prior to infusion of phenylephrine. Removal of sympathetic innervation to cerebral vessels attenuated, but did not eliminate, effects of L-NA on breakthrough. Thus, vasodilatation seen with breakthrough of autoregulation depends upon release of nitric oxide or a nitric oxide donor.     

8-Gbit/s transmission experiment over 68 km of optical fiber using a Ti:LiNbO3external modulator

We describe the performance of an experimental 1.5-μm lightwave transmission system operating at 8 Gbit/s over 68.3 km of single-mode fiber. The dispersion penalty is limited to 1 dB through the use of external modulation and is attributable to the intrinsic information bandwidth.     

‘Podracing’: experimenting with mobile TV content consumption and delivery methods

Recently, mobile TV has been launched in several countries. While mobile TV integrates television contents into mobile phones, the most personal of communication devices, it becomes interesting to know how this feature will be used throughout the day and in varying contexts of everyday life. This paper presents empirical results on the use of mobile TV with different delivery mechanisms and both quantitative and qualitative results on how end-users prefer to use mobile TV contents in different situations. The data is based on ongoing empirical research in Finland in 2006 and 2007. The mobile TV services under study included both news and entertainment contents, and were tested in 3G, DVB-H and Wi-Fi networks using different delivery paradigms: broadcast, on-demand and download. To explore the use of different delivery methods and content consumption, we have developed a mobile TV service protoype, called Podracing. The analysis shows that users appreciated up-to-date information and information-rich media forms and contents especially for mobile news delivery. There was high demand for only the latest news on mobiles. The real-time property was considered important. Most of the users looked at the headlines or followed the news several times a day – much more often than the traditional TV and news prime times would allow.     

NumSBT: A subroutine for calculating spherical Bessel transforms numerically

A previous subroutine, LSFBTR, for computing numerical spherical Bessel (Hankel) transforms is updated with several improvements and modifications. The procedure is applicable if the input radial function and the output transform are defined on logarithmic meshes and if the input function satisfies reasonable smoothness conditions. Important aspects of the procedure are that it is simply implemented with two successive applications of the fast Fourier transform, and it yields accurate results at very large values of the transform variable. Applications to the evaluation of overlap integrals and the Coulomb potential of multipolar charge distributions are described.

Program summary

Program title: NumSBTCatalogue identifier: AANZ_v2_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AANZ_v2_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 476No. of bytes in distributed program, including test data, etc.: 4451Distribution format: tar.gzProgramming language: Fortran 90Computer: GenericOperating system: LinuxClassification: 4.6Catalogue identifier of previous version: AANZ_v1_0Journal reference of previous version: Comput. Phys. Comm. 30 (1983) 93Does the new version supersede the previous version?: NoNature of problem: This program is a subroutine which, for a function defined numerically on a logarithmic mesh in the radial coordinate, generates the spherical Bessel, or Hankel, transform on a logarithmic mesh in the transform variable. Accurate results for large values of the transform variable are obtained, that would not be otherwise obtainable.Solution method: The program applies a procedure proposed by the author [1] that treats the problem as a convolution. The calculation then requires two applications of the fast Fourier transform method.Reasons for new version: The method of computing the transform at small values of the transform variable has been substantially changed and the whole procedure simplified. In addition, the possibility of computing the transform for a single transform variable value has been incorporated. The code has also been converted to Fortran 90 from Fortran 77.Restrictions: The procedure is most applicable to smooth functions defined on (0,∞) with a limited number of nodes.Running time: The example provided with the distribution takes a few seconds to execute.References:[1] J.D. Talman, J. Comp. Phys. 29 (1978) 35.     

Sex Pheromones of the American Cockroach,Periplaneta americana

Two sex pheromones, periplanone A and periplanone B were isolated from the American cockroach Periplaneta americana. The technique is described for collecting periplanone B from the alimentary tracts of virgin females. Periplanone A was extracted from the excreta of the insects. Mass spectral analysis of the pheromones and related compounds were performed and the results are reported here. Evidence is presented suggesting that periplanone A is in fact a degradation product of periplanone B. A reaction scheme is considered for the pathway: periplanone B → periplanone A → (stable, but inactive) PA 22–VII.     

Perceptions of and satisfaction with retirement: A comparison of six European Union countries.

The main aim of this study was to assess perceptions of and satisfaction with retirement among 1,686 recently retired people from 6 European Union countries. The authors compared their responses to a set of questions taken from the Retirement Satisfaction Inventory (F. J. Floyd et al., 1992). The first significant result was that Belgian, British, Finnish, French, and Spanish retirees all expressed very similar assessments of life satisfaction, whereas Portuguese retirees expressed a lower level of satisfaction. The 2nd result was that the major determinants of overall satisfaction in the 6 countries were (a) health and resources and (b) anticipated satisfaction. Finally, the data revealed that cultural background only accounted for a limited amount of variance in overall satisfaction with retirement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

UX Curve: A method for evaluating long-term user experience

The goal of user experience design in industry is to improve customer satisfaction and loyalty through the utility, ease of use, and pleasure provided in the interaction with a product. So far, user experience studies have mostly focused on short-term evaluations and consequently on aspects relating to the initial adoption of new product designs. Nevertheless, the relationship between the user and the product evolves over long periods of time and the relevance of prolonged use for market success has been recently highlighted. In this paper, we argue for the cost-effective elicitation of longitudinal user experience data. We propose a method called the “UX Curve” which aims at assisting users in retrospectively reporting how and why their experience with a product has changed over time. The usefulness of the UX Curve method was assessed in a qualitative study with 20 mobile phone users. In particular, we investigated how users’ specific memories of their experiences with their mobile phones guide their behavior and their willingness to recommend the product to others. The results suggest that the UX Curve method enables users and researchers to determine the quality of long-term user experience and the influences that improve user experience over time or cause it to deteriorate. The method provided rich qualitative data and we found that an improving trend of perceived attractiveness of mobile phones was related to user satisfaction and willingness to recommend their phone to friends. This highlights that sustaining perceived attractiveness can be a differentiating factor in the user acceptance of personal interactive products such as mobile phones. The study suggests that the proposed method can be used as a straightforward tool for understanding the reasons why user experience improves or worsens in long-term product use and how these reasons relate to customer loyalty.     

Managing the Senegal River: National and Local Development Dilemma

The Senegal River is located in West Africa in the Sudano-Sahelian zone. The river has faced various development schemes since the early 1970s, which have not brought the desired results. Many problems stem from the overall lack of economic and human development and weak institutional settings. Droughts and ethnic complexities add to the problem. The environment and local population have continuously been exposed to negative changes. The river developers face a difficult task when choosing the development options for the future. Taking into account all the stakeholders and variables, and adding to these the external demographic and natural challenges, the development actions require weighing complex multiform and interconnected issues. An objective analysis of the development plans is needed in order to avoid repeating past mistakes and to acquire harmonious end results.     

The Measurement of Business Intelligence

Based on a literature review, this article identifies and assesses measurement approaches for two different purposes: determining the value of BI and managing the BI process within an organization.     

Direct evidence for nitric oxide synthase in vagal afferents to the nucleus tractus solitarii

The anatomical relationship between vagal afferents and brain nitric oxide synthase containing terminals in the nucleus tractus solitarii was studied by means of anterograde tracing combined with immunocytochemistry and immuno-electron microscopy. Biotinylated dextran amine was injected into the nodose ganglion with a glass micropipette. Four to eight days following the injection, regions of the nucleus tractus solitarii containing biotinylated dextran amine-labelled vagal afferents and those containing nitric oxide synthase-immunopositive terminals were congruent. Many neurons exhibiting nitric oxide synthase immunoreactivity were found within the biotinylated dextran amine-containing terminal field. However dense labeling of terminals with biotinylated dextran amine precluded determination if the terminals were nitric oxide synthase-immunoreactive. Therefore, we combined degeneration of vagal afferents after removal of one nodose ganglion with nitric oxide synthase immuno-electron microscopy. Axon terminals that possessed characteristic vesicle clusters and were partially or completely engulfed by glial processes were identified as degenerating vagal afferents. Degenerating axon terminals comprised 38% of the total axon terminals in the nucleus tractus solitarii in a sample of sections; and of the degenerating axon terminals, 67% were nitric oxide synthase-immunoreactive. Nitric oxide synthase immunoreactivity was present in 41% of the non-degenerating axon terminals. Prominent staining of dendrites for nitric oxide synthase immunoreactivity indicated that much of the nitric oxide synthase in the nucleus tractus solitarii is not derived from peripheral afferents. Of the total number of dendritic profiles sampled, half were nitric oxide synthase-immunoreactive. Our data support the hypothesis that nitric oxide or nitric oxide donors may be present in primary vagal afferents that terminate in the nucleus tractus solitarii. While this study confirms that vagal afferents contain brain nitric oxide synthase, it demonstrates for the first time that the majority of nitric oxide synthase immunoreactivity in the nucleus tractus solitarii is found in intrinsic structures in the nucleus. In addition, our data show that second or higher order neurons in the nucleus tractus solitarii may be nitroxidergic and receive both nitroxidergic and non-nitroxidergic vagal input.