Brain noradrenergic responses to footshock after chronic activity-wheel running.

Effects of physical activity on brain noradrenergic response to footshock were examined. Male Fischer 344 rats were randomly assigned to shoebox cages with (AW) or without (SED) 24-hr access to an activity wheel for 4–5 weeks. Extracellular levels of norepinephrine (NE) and 3,4-dihydroxyphenyl-acetic acid (DOPAC) in the brain frontal cortex were measured in 20-min samples of microdialysate taken during a 2-hr baseline, 40 min of scrambled footshock, and a 1-hr recovery. Levels of messenger RNA (mRNA) for tyrosine hydroxylase (TH), c-fos, and prepro-galanin in the locus coeruleus were measured by in situ hybridization histochemistry with autoradiographic analysis. NE levels were the same for SED and AW rats at baseline but were elevated in SED compared with AW during and after footshock. Levels of mRNA for TH and c-fos were elevated after footshock but did not differ between SED and AW. Our findings suggest that wheel running blunts NE release in the brain frontal cortex in response to footshock but does not influence expression of the gene that encodes TH in the locus coeruleus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Association of compartment defects in pelvic floor dysfunction

OBJECTIVE: Dynamic cystoproctography was used to determine the frequency of associated urinary, genital, and anorectal abnormalities in women with pelvic floor dysfunction. SUBJECTS AND METHODS: We categorized, by pelvic floor compartments, the symptoms at presentation of 100 consecutive female patients who had been referred for dynamic cystoproctography. We then analyzed the compartment defects seen on dynamic cystoproctography relative to those detected on clinical presentation. RESULTS: Of the 20 patients with symptoms of anterior compartment (urinary) defect, dynamic cystoproctography revealed that 45% had vaginal vault prolapse of more than 50% and that 90% had rectoceles. Of the 45 patients with symptoms of middle compartment (genital) defect, dynamic cystoproctography revealed that 91% had cystoceles, 56% had a hypermobile bladder neck, 82% had rectoceles, 58% had enteroceles, 11% had sigmoidoceles, 20% had rectoanal intussusception, and 16% had anal incontinence. Of the 17 patients with symptoms of posterior compartment (anorectal) defect, dynamic cystoproctography showed that 71% had cystoceles, 65% had a hypermobile bladder neck, and 35% had vaginal vault prolapse of more than 50%. Of the 18 patients with symptoms of defects from a combination of compartments, dynamic cystoproctography revealed that 89% had cystoceles, 56% had a hypermobile bladder neck, 39% had vaginal vault prolapse exceeding 50%, 100% had rectoceles (of which 45% were large), 6% had enteroceles, 6% had sigmoidoceles, 22% had rectoanal intussusception, and 6% had anal incontinence. CONCLUSION: Although patients may present with symptoms that involve only one compartment, a multicompartment prolapse is usually revealed on dynamic cystoproctography. Of the patients with pelvic floor dysfunction, 95% had abnormalities in all three compartments.     

卫星提供商在亚洲的机会和风险均等

亚洲为卫星运营商的成功提供了诸多的强劲动力，这是因为像中国和印度这样的人口大国急需得到更多的通信服务，与此同时，其他一些国家似乎也很适合卫星通信。然而，尽管拥有明显的潜力，管理和经济问题却表明：卫星运营商要充分利用这些机会并非易事。     

Modeling viscoelastic secondary flows in three‐dimensional noncircular ducts

As process capabilities become more advanced, the need to predict flow phenomena at a smaller scale increases significantly. Viscoelastic secondary flows in square ducts were simulated using a finite volume approach. Single mode and multimode Giesekus and Phan‐Thien Tanner (PTT) models were implemented and were able to reproduce full three‐dimensional (3D) flow through a square duct. Results for low density polyethylene (LDPE), polystyrene, and polycarbonate are all in agreement with experiments [Dooley, Viscoelastic flow effects in multilayer polymer coextrusion, PhD Thesis, Technische Universiteit Eindhoven (2002)] as well as numerical results using a finite element method (FEM) and a meshless radial function method (RFM), [Lopez et al., SPE ANTEC Tech. Pap. (2010)]. The mathematical model presented here has shown the potential to model full 3D flow in more complex geometries. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

Learning classifier systems: New models, successful applications

Rules are an accepted means of representing knowledge for virtually every domain. Traditional machine learning methods derive rules by exploring sets of examples using statistical or information theoretic techniques. Alternatively, rules can be discovered through methods of Evolutionary Computation such as genetic algorithms and learning classifier systems.In recent years, new models of learning classifier systems have been developed which have resulted in successful applications in a wide variety of domains (e.g., autonomous robotics, classification, knowledge discovery, modeling). These models have led to a resurgence of this area which for a certain period appeared almost at a dead end. This paper overviews the recent developments in learning classifier systems research, the new models, and the most interesting applications, suggesting some of the most relevant future research directions.     

电力系统保护新技术

电子科技大学应用超导与电工技术研究中心的科研人员发明出一种电力系统保护新技术——复合高温超导电力系统故障电流限流器。该项技术发明已申请国家专利。     

Modeling ultrasonic compression wave absorption during the seeded crystallization of copper (II) sulphate pentahydrate from aqueous solution

Ultrasonic compression wave absorption is investigated as a means to monitor the seeded crystallization of copper (II) sulphate pentahydrate from aqueous solution. Simple models are applied to predict crystal yield, crystal size distribution, and the changing nature of the continuous phase. The Allegra-Hawley scattering formulation is used to simulate ultrasonic absorption as crystallization proceeds. Experiments confirm that simulated attenuation is in agreement with measured results.     

Fluorescent infrared scanning-laser ophthalmoscope for three-dimensional visualization: automatic random-eye-motion correction and deconvolution

Scanning-laser ophthalmoscope (SLO) technology has provided, among other possibilities, the potential for three-dimensional (3-D) visualization of anatomy in the posterior pole of the eye. The use of indocyanine green (ICG) as an infrared fluorescent marker of vasculature in combination with aninfrared SLO (the Heidelberg Retina Angiograph) is presented. Presently, two main factors among others discussed impede the visualization of 3-D structures in observed SLO data. Random eye motion between optical sections and (to a lesser degree) motion between raster scan lines prevent assessment of spatial orientation and connectivity of vasculature. Second, smear along the optic axis owing to the optics prevents accurate determination of vessel or lesion size and shape, especially for features spanning several optical sections. A novel, to our knowledge, deconvolution algorithm is described that automatically corrects for the poor axial (optical-sectioning) resolution of the SLO and for patient random eye motion during target fixation. Encouraging preliminary results are presented showing the usefulness of applying blind deconvolution toward improving the 3-D clarity of SLO data. Although clinical and medical research applications are broad, the specific medical sample selected shows the potential of examining microvascular 3-D morphology for diagnosis and treatment of choroidal tumors.     

Characterizing stimulus-response functions using nonlinear regressors in parametric fMRI experiments

A vector model for the simultaneous contrast of equiluminant colors is proposed. The main characteristics of simultaneous color contrast are associated with the interaction of the test and induction fields. The mechanisms of color contrast depend on the activity of neurons which subtract excitation arising in analogous neurons of the test and induction fields. Signals from the "subtractor" neurons pass via local inputs to "adder" neurons. Selective color detectors are excited by contributions from the adder neurons. When the induction and test fields are of identical color and their excitation vectors coincide, the color of the test field depends on neurons excited only in the test field, and the induction field has no effect on the color of the test field. When the test and induction fields are of different color tone or saturation, the color of the induction field affects the color of the test field such that the excitation vector of the test field diverges from the excitation vector of the induction field. This model can be used for analysis of neurophysiological and psychophysiological studies of color contrast.     

Effect of horizontal vergence on the motor and sensory components of vertical fusion

PURPOSE: To compare motor and sensory capabilities for fusion of vertical disparities at different angles of horizontal vergence in healthy humans. METHODS: Eye movements were recorded from both eyes of 12 healthy subjects using three-axis search coils. The stimulus was a cross (+) (3.4 x 3.2 degrees , vertically and horizontally, respectively) presented to each eye with a stereoscopic display. Vertical disparities were introduced by adjusting the vertical position of the cross in front of one eye. The disparity was increased in small increments (0.08 degrees ) every 8 seconds. Viewing was defined as "near" if there was a horizontal disparity that elicited 6 degrees to 15 degrees convergence, depending on the subject's capability for horizontal fusion; viewing was defined as "far" at 1 degrees convergence. Maximum motor (measured), sensory (stimulus minus motor), and total (motor plus sensory) vertical fusion were compared. RESULTS: In 9 (75%) of 12 subjects the maximum total vertical fusion was more in near than in far viewing. The three who did not show this effect had relatively weak horizontal fusion. For the entire group, the motor component differed significantly between far (mean, 1.42 degrees ) and near (mean, 2.13 degrees). Total vertical fusion capability (motor plus sensory) also differed significantly between far (mean, 1.68 degrees ) and near (mean, 2.39 degrees ). For the sensory component there was no difference between between far (mean, 0.268 degrees ) and near (mean, 0.270 degrees ). As vertical disparity increased in a single trial, however, there was a small gradual increase of the contribution of the sensory component to vertical fusion. CONCLUSIONS: Vertical fusion capability usually increases with convergence. This increase is caused primarily by an increase in the motor component. There is a gradual but small increase in the sensory component as target disparity slowly increases.