Children's referential communication: Components of plans for effective listening.

Investigated the effects of 2 plans on children's listener behavior in a referential communication setting. The design systematically varied the presence and absence of instructions about a plan to engage in comparison activities (comparison plan) and instructions about a plan to request more information if the speaker's message was ambiguous (action plan). 94 elementary school Ss played the role of listener. The speaker was an adult confederate who produced messages of varying informational adequacy. Results show that on an immediate test, Ss who received the action plan asked more questions when the messages were ambiguous and made more correct referent choices than other Ss. These effects persisted on a test administered 2 wks later and were observed both for nameable and abstract stimulus items. No significant effect of the comparison plan was observed. Results suggest that knowing when and how to request additional information is an important listener skill. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Colour Doppler energy (power) mode ultrasound

During the study period, 24,492 pregnant women attended the Harris Birthright Research Centre at 10-14 weeks of gestation, at which time, in addition to the measurements of nuchal translucency thickness and crown-rump length (CRL), data on fetal abnormalities were recorded onto a computer database. Cases of megacystis were identified and the records were reviewed. Additionally, the relationship of the longitudinal bladder diameter with the CRL and the bladder diameter/CRL ratio (expressed as a percentage) were examined with the use of data from 300 normal fetuses at 10-14 weeks. Megacystis was present in 15 of the 24,492 pregnancies (1 in 1,633) and in these cases the minimum longitudinal bladder diameter was 8 mm and the minimum bladder diameter/CRL ratio was 13%. In the 300 control fetuses the bladder was visualized in 278 (92.7%) of the cases and the longitudinal bladder diameter increased with the CRL (bladder diameter = 0.065 x CRL - 0.69; r = 0.47, p < 0.001), none of the measurements was more than 6 mm and the median bladder diameter/CRL ratio was 5.4% (range 0-10.4%) which did not change significantly with gestation (r = 0.1, p = 0.09). The bladder was visible in all cases with a minimum CRL of 67 mm. In three of the 15 cases with megacystis, there were chromosomal abnormalities. In the chromosomally normal group, there were seven cases with spontaneous resolution, whereas in four cases there was progression to severe obstructive uropathy. The bladder diameter was 8-12 mm and the bladder diameter/CRL ratio 13-22% in all cases with resolution and in one case with progressive megacystis; in the other three cases with progressive obstruction, the bladder length was more than 16 mm and the bladder diameter/CRL ratio was more than 28%.     

Minimally invasive valve operations

BACKGROUND: To reduce the morbidity from valvular heart operations, a right parasternal approach was introduced. We report our initial experience with the procedure. METHODS: From January 1996 through July 1996, 115 patients underwent primary isolated valve procedures. One hundred (85%) patients underwent the operation through a right parasternal incision. RESULTS: There was one hospital death secondary to a stroke on the fifth postoperative day. Three patients (two with aortic valve operations and one having a mitral valve procedure) required conversion to sternotomy. Mean aortic occlusion time was 71 minutes; mean cardiopulmonary bypass time was 93 minutes. Mean stay in the intensive care unit was 27 hours and mean hospital postoperative stay was 5.7 days. Seventy-seven percent of the patients did not receive blood transfusions. Comparison with median sternotomy demonstrated a reduction in both postoperative length of stay and direct hospital costs. CONCLUSIONS: We conclude that this minimally invasive approach is safe for a variety of valve procedures and is effective in reducing surgical trauma and cost.     

Tricuspid valve surgery and intraoperative echocardiography: factors affecting survival, clinical outcome, and echocardiographic success

BACKGROUND: The impact of echocardiographic-guided treatment on outcome after tricuspid valve (TV) surgery is not well defined. OBJECTIVES: The purpose of this study was to determine clinical and echocardiographic factors associated with adverse outcomes after TV surgery and determine the role of intraoperative echo (IOE) in facilitating successful outcomes after TV surgery. METHODS: Four hundred and one patients (279 females, mean age 60 years) underwent TV surgery and other concomitant cardiac surgery at a single institution and were followed clinically and by echocardiography during a 10-year period. RESULTS: Decreased survival after TV surgery was associated with: preoperative increased New York Heart Association (NYHA) functional classification (relative risk [RR]=2.02), increased left ventricular dysfunction by echocardiography (RR=1.28), and use of a TV replacement strategy (RR=2.92). Decreased event-free survival after TV surgery was associated with concomitant coronary artery bypass grafting (RR=2.97). Late echocardiographic failure (3 to 4+ tricuspid valve regurgitation [TR]) after TV surgery was associated with increased severity of TR on preoperative echocardiogram (odds ratio [OR]=1.91). Decreased late echocardiographic failure after TV surgery was associated with the use of a TV annuloplasty ring with a repair strategy (OR=0.40). The surgical plan was altered at the time of surgery to insure a successful outcome in 32 (10%) of 335 patients based on IOE findings. CONCLUSIONS: Adverse outcomes after TV surgery can be predicted by several preoperative clinical and echocardiographic variables. IOE is useful in improving immediate, but not late, outcomes after TV surgery.     

The sorption of iso-propyl nitrate and acetone into nitrocellulose/nitroglycerine films

Rates of sorption of iso-propyl nitrate and acetone vapour into nitrocellulose films plasticized with nitroglycerine have been measured. In all cases, although fractional uptakes were approximately proportional to the square root of time, they were also independent of film thickness. Such behaviour indicates a ‘Case III’ mechanism in which the film expands uniformly with no appreciable concentration gradients. A kinetic equation, which describes uptakes of up to 90% is suggested.     

Mapping the positions of beads on a string: dethreading rotaxanes by molecular force spectroscopy

The direct manipulation by atomic force microscopy (AFM) of individual macrocycles within a rotaxane offers a potential route to a new sequencing tool for complex macromolecules such as polysaccharides, glycoproteins and nucleic acids. In this paper we demonstrate for the first time that a sliding contact made between a macrocycle, α-cyclodextrin, and its polymer axle by an AFM tip can be used to map the positions of specific groups along the polymer as if they were beads along a string, thereby generating sequence information. We find very good agreement (linear fit with slope = 1.03, R(2) = 0.968) between the calculated and measured positions of phenylenediamine and benzenetricarboxylic acid groups within polymers of polyethylene oxide?(PEO). The rupture force profiles attributable to the dethreading interactions of phenylenediamine and benzenetricarboxylic acid differ observably from each other and, in the latter case, from the rupture of the corresponding host-guest complex. As well as opening the way to a macromolecular sequencing technique, the ability demonstrated by this method to?manipulate the dethreading of a rotaxane offers a new tool for investigating the process?energetics in a wide array of spontaneously forming and forced rotaxane systems.     

Quantitative visualization of ultrasonic acoustic waves by means of digital laser speckle-technologies

An original version of digital laser speckle photography has been used for visualization and quantitative diagnosis of acoustic waves in liquids in the megahertz frequency range. Standing acoustic waves were generated in tanks of special configuration which permitted obtaining analytical dependences of refraction angles of the probe laser radiation on the wave intensity. These refraction angles were determined experimentally by the change in contrast of the speckle fields arising in the scattered probe radiation and recorded by means of high-resolution digital CCD matrices. Quantitative diagnosis of the pressure and velocity fields in acoustic waves was carried out by measuring the deformation of the laser intensity correlation functions in recorded speckle fields. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 81, No. 2, pp. 229–239, March–April, 2008.     

A model of cell wall expansion based on thermodynamics of polymer networks

A theory of cell wall extension is proposed. It is shown that macroscopic properties of cell walls can be explained through the microscopic properties of interpenetrating networks of cellulose and hemicellulose. The qualitative conclusions of the theory agree with the existing experimental data. The dependence of the cell wall yield threshold on the secretion of the wall components is discussed.