Instant messaging: A cross-country comparison of factors affecting adoption

This research-in-progress paper utilizes the Technology Acceptance Model (TAM) to determine whether differences exist in the adoption of Instant Messaging (IM) Technologies in Australia, China, Mexico and the USA. Despite significant differences in the technology needed to implement IM (e.g., software supporting Chinese language characters), few barriers exist to the adoption of IM given the environment is in place. We postulate that language interface technology, infrastructure, and culture affect the adoption of IM technology.

Particle formation during soy protein precipitation

The current success of soy foods is driving soy ingredient manufacturers to develop innovative products for food manufacturers. One such innovation is separating the soy proteins glycinin and beta-conglycinin to take advantage of their individual functional and nutritional properties. Precipitation by acidification is a low-cost method for separating these two proteins. Separation is achieved by preferentially precipitating glycinin at pH ~ 6 while beta-conglycinin remains in solution. Understanding the particle formation during protein precipitation is important as it can influence the efficiency of the precipitation process as well as subsequent downstream processes such as the particle-liquid separation step, usually achieved by centrifugation. Most of the previous soy protein precipitation studies are limited to precipitation at pH 4 as this is the pH range most commonly used in the commercial manufacturing of soy protein isolates. To date, there have been no studies on the particle formation during precipitation at pH > 5.Precipitation of soy protein is generally thought to occur by the rapid formation of primary particles in the size range of 0.1 - 0.3 microns followed by aggregation of these particles via collision to aggregates of size about 1 - 50 microns. The formation of the primary particles occurs on a time scale much shorter than that of the overall precipitation process (Nelson and Glatz, 1985). This study shows that precipitation of soy protein is indeed rapid. At high pH levels, binary liquid-liquid separation occurs forming a protein-rich heavy phase. The protein-rich phase appears as droplets which can be coalesced to form a uniform bulk layer under centrifugation forces. Upon lowering the pH level by the addition of acid, further protein is precipitated as amorphous material which binds the droplets together to form aggregates of amorphous precipitates. Liquid-liquid separation has been observed in many protein solutions but this phenomenon has only scarcely been reported in the literature for soy proteins. It presents an exciting opportunity for an innovative product. Features of the liquid-phase protein such as protein yield and purity will be characterized.

Coronary revascularization can improve regional left ventricular volumes in non-transmural scars without contractile reserve

Revascularization (RVS) of scar segts does not lead to recovery of left ventricular (LV) function, but its effect on post-infarct remodeling is unclear. We examined the impact of RVS on regional remodeling in different transmural extents of scar (TME). Dobutamine echo (DbE) and contrast enhanced magnetic resonance imaging (ce- MRI) were performed in 72 pts post MI (age 63±10, EF 49±12%). Pts were selected for RVS (n = 31) or medical treatment (n = 41). Segts were classified as scar if there were no contractile reserve during lowdose DbE.TMEwas measured by ce-MRI; a cutoff of 75% was used to differentiate transmural (TM) from non-transmural (NT) scars. Regional end systolic (ESV) and end diastolic volumes (EDV) were measured at baseline and 12 months follow up.Of 218 segts identified as scar on DbE, 164wereNTand 54 were TM on ce-MRI. Revascularization was performed to 62 NT and 11 TM segts. In the RVS group, there was reverse remodeling with significant reduction in LV volumes in NT (ESV, 6.8±3.2 ml versus 5.8±3.7 ml, p = 0.002; EDV, 10.9±4.9 ml versus 9.8±5.6 ml, p = 0.02), but no significant change in volumes in TM (ESV, 6.9±3.7 ml versus 5.4±2.1 ml, p = 0.09; EDV, 10.2±4.4 ml versus 9.4±4.3 ml, p = 0.5). In the medically treated group, there were no changes in LV volumes in both NT (ESV, 12.0±11.9 ml versus 12.7±13.8 ml, p = 0.3; EDV, 12.5±7.8 ml versus 12.6±9.7 ml, p = 0.8) and TM (ESV, 8.0±3.8 ml versus 7.9±4.6 ml, p = 0.8; EDV, 10.3±4.8 ml versus 10.4±5.4 ml, p = 0.9). Despite absence of contractile reserve on DbE, NT benefit from coronary revascularization with regional reverse LV remodeling.

Local geometric changes in left ventricular remodeling post-infarction can lead to apparent reduction in scar thickness

Serial reduction in scar thickness has been shown in animal models. We sought whether this reduction in scar thickness may be a result of dilatation of the left ventricle (LV) with stretching and thinning of the wall. Contrast enhanced magnetic resonance imaging (CMRI) was performed to delineate radial scar thickness in 25 patients (age 63±10, 21 men) after myocardial infarction. The LV was divided into 16 segts and the absolute radial scar thickness (ST) and percentage scar to total wall thickness (%ST) were measured. Regional end diastolic (EDV) and end systolic volumes (ESV) of corresponding segments were measured on CMRI. All patients underwent revascularization and serial changes in ST, %ST, and regional volumes were assessed with a mean follow up of 15±5 months. CMRI identified a total of 93 scar segments. An increase in EDV or ESV was associated with a serial reduction inST(versusEDV, r =−0.3, p = 0.01; versusESV, r =−0.3, p = 0.005) and%ST(versusEDV, r =−0.2, p = 0.04; versus ESV, r =−0.3, p = 0.001). For segts associated with a positive increase in EDV (group I) or ESV (group II) there was a significant decrease in ST and %ST, but in those segts with stable EDV (group III) or ESV (group IV) there were no significant changes in ST and %ST (Table).

Relative predictive value of intraventricular dysynchrony in determining long-term outcome in patients with known or suspected coronary disease

Improvement of intra-ventricular dysynchrony (IVD) in pts undergoing bi-ventricular pacing is associated with clinical improvementbut little isknownabout the relationship between IVD and prognosis.We sought whether IVD influences long-term outcome in pts with known or suspected coronary disease (CAD). Tissue Doppler imaging was performed in 184 pts (aged 61±10 years, 67% male) prior to dobutamine echo. From velocity curves the interval between QRS onset and max systolic velocity (Ts) was measured in basal septal, lateral, inferior and anterior segments. The maximal difference in Ts between segments (TsMax) was used as a measure of IVD. The standard deviation (TsSD) between all segments and the septal-lateral difference (TsSL) were also calculated. Pts were followed up for a median interval of 5 years and a Cox model used for survival analysis. The medianwall motion index (WMI) was 1.3 (IQR 1.0–1.8) at rest and 1.4 (IQR 1.3–1.9) at stress. The table shows IVD parameters. Forty-one deaths occurred during follow-up. Pts who died during follow-up, compared to survivors, showed greater IVD. WMI at rest (p = 0.03) and peak stress (p = 0.02), TsSD (p = 0.06), TsSL (p = 0.02) and TsMax (p = 0.05) but not QRS width were univariate predictors of mortality. TsSL was the only independent predictor of death (p = 0.01). Therefore, IVD is common in pts with known or suspected CAD. Pts with more IVD have reduced long-term survival, independent of WMI.

Reduction in scar thickness post myocardial infarction is secondary to increase in regional left ventricular volumes

We sought to determine the relative impact of myocardial scar and viability on post-infarct left ventricular (LV) remodeling in medically-treated patients with LV dysfunction. Forty patients with chronic ischemic heart disease (age 64±9, EF 40±11%) underwent rest-redistribution Tl201 SPECT (scar = 50% transmural extent), A global index of scarring for each patient (CMR scar score) was calculated as the sum of transmural extent scores in all segts. LV end diastolic volumes (LVEDV) and LV end systolic volumes (LVESV) were measured by real-time threedimensional echo at baseline and median of 12 months follow-up. There was a significant positive correlation between change in LVEDV with number of scar segts by all three imaging techniques (LVEDV: SPECT scar, r = 0.62, p < 0.001; DbE scar, r = 0.57, p < 0.001; CMR scar, r = 0.52, p < 0.001) but change in LV volumes did not the correlate with number of viable segments. ROC curve analysis showed that remodeling (LVEDV> 15%) was predicted bySPECTscars(AUC= 0.79),DbEscars(AUC= 0.76),CMR scars (AUC= 0.70), and CMR scar score (AUC 0.72). There were no significant differences between any of the ROC curves (Z score

It's all in the game: Teaching software process concepts

A major challenge in teaching software engineering to undergraduates is that most students have limited industry experience, so the problems addressed are unknown and hence unappreciated. Issues of scope prevent a realistic software engineering experience, and students often graduate with a simplistic view of software engineering’s challenges. Problems and Programmers (PnP) is a competitive, physical card game that simulates the software engineering process from requirements specification to product delivery. Deliverables are abstracted, allowing a focus on process issues and for lessons to be learned in a relatively short time. The rules are easy to understand and the game’s physical nature allows for face-to-face interaction between players. The game’s developers have described PnP in previous publications, but this paper reports the game’s use within a larger educational scheme. Students learn and play PnP, and then are required to create a software requirements specification based on the game. Finally, students reflect on the game’s strengths and weaknesses and their experiences in an individual essay. The paper discusses this approach, students’ experiences and overall outcomes, and offers an independent, critical look at the game, its use, and potential improvements.