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Introduction Numerous studies have shown that the constructs of the Theory of Reasoned Action (TRA), Theory of Planned Behavior (TPB) and Breastfeeding Self-Efficacy (BSE) Framework can effectively identify relationships between maternal psychosocial factors and breastfeeding initiation. However, the ability of these theories to predict breastfeeding duration has not been adequately analyzed. The aim of the review was to examine the utility of the constructs of TRA/TPB and BSE to predict breastfeeding duration. Methods We conducted a literature search using Pubmed (1980-May 2015), Medline (1966-May 2015), CINAHL (1980-May 2015), EMBASE (1980-May 2015) and PsycINFO (1980-May 2015). We selected studies that were observational studies without randomization or blinding, using TRA, TPB or BSE as the framework for analysis. Only studies reporting on breastfeeding duration were included. Results Thirty studies were selected, which include four using TRA, 10 using TPB, 15 using BSE and one using a combination of TPB and BSE. Maternal intention and breastfeeding self-efficacy were found to be important predictors of breastfeeding duration. Inconsistent findings were found in assessing the relationship between maternal attitudes, subjective norms, perceived behavior control and breastfeeding duration. Discussion The inadequacy of these constructs in explaining breastfeeding duration indicates a need to further explore the role of maternal self-determination in breastfeeding behavior.

Background although new mothers are aware of the benefits of breastfeeding, many of them stop breastfeeding early in the postpartum period. Maternal psychosocial factors have been shown to contribute to early breastfeeding cessation. According to Self-Determination Theory (SDT) maternal self-determination is an indispensable factor in studying motivation to breastfeed. There are no validated instruments to assess maternal breastfeeding motivation and self-determination. Objective our aim was to develop and assess the psychometric properties of the Breastfeeding Self -Regulation Questionnaire (BSRQ) for Chinese pregnant women in Hong Kong. Method we reviewed the literature and devised items for a preliminary version of the questionnaire. Thirty-five context-specific items in English were generated. We translated the items into Chinese and then back translated them into English following established translation procedures. We employed exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) to assess the structure of the questionnaire. Predictive validity was measured by assessing the relationship between the BRSQ score and actual duration of breastfeeding. Findings we recruited 591 participants from three publicly funded antenatal clinics. Of the 35 items in the preliminary BSRQ, 22 were retained by EFA. CFA revealed that there were 5 factors including intrinsic, identified, integrated, introjected and external regulation. The goodness of fit of the CFA model was adequate. The Cronbach's alpha of the BSRQ was 0.86. For every one point increase in the BSRQ score, participants had 15% higher odds of any breastfeeding (OR=1.15, 95%CI 1.07–1.23) and 9% higher odds of exclusive breastfeeding (OR=1.09, 95%CI 1.02–1.17) at 6 weeks postpartum. Conclusion the Chinese version of the BSRQ was a valid and reliable tool to measure maternal self-determination towards breastfeeding.

In this study, a virtual-reality (VR) pedestrian simulation method was used to evaluate the risks to pedestrians crossing streets in a traffic system with driving rules that were unfamiliar to them. Pedestrians from mainland China (which has a right-side driving (RD) system) and Hong Kong (which has a left-side driving (LD) system) were studied. Significant differences were observed between pedestrians from the different locations in terms of the direction in which the pedestrians habitually first looked before crossing. When exposed to an unfamiliar driving rule (i.e., traffic coming from an inconsistent direction in terms of participants’ habitual driving system), the odds of participants from mainland China making an error in their looking behavior were 2.93 times those when exposed to a familiar driving rule. Road markings and traffic sound did not improve these participants’ looking behavior. The results also show a negative correlation between inattentive looking behavior and time to collision (significant at the 1% level), as these errors lead to a shorter time to collision and increased the risk to pedestrians. The results of this study confirmed the risks for pedestrians traveling to places with unfamiliar driving rules and confirmed the existence of habitual looking behavior, and therefore provide evidence of the need for future studies to improve this problem. These may help decision makers take the risks of pedestrians from different driving rules into consideration in future traffic policymaking or traffic-facility improvements. The use of a VR simulation-based approach in this study provided a safe and controllable way to trial interventions and potential improvements without risking injury to participants, and thus may also be used for similar future studies.

The dielectric constant of dielectric elastomer(DE) is an important physical parameter that affects the performance of DE actuator. A number of factors may cause an effect on the value of the dielectric constant. In this paper, an extensive experimental study has been conducted to investigate the relation between dielectric constant and two factors, electrical frequency and biaxial prestretch ratio quantitatively. The experimental results show that the dielectric constant varies with the variation of the frequency of the sensing signal and prestretch ratio. The analyses and the recorded results provide a reference to researchers about the quantitative control of dielectric elastomer actuator relating to the two key parameters. An experimental platform has been developed for actuating and sensing of a prototype dielectric elastomer actuator that demonstrates the design for actuating and self-sensing control under varying dielectric constant. An area stretch ratio of more than 220% is obtained through the proposed design.

With the recent rising popularity of music streaming platforms, consumers are now able to enjoy music as a service, playing music for free without paying to obtain the ownership, the threat to the record labels’ financial prospect is eminent. We propose a novel decision support framework to assist the record label in making better informed decisions in the postrelease management timeframe to maximise the expected profit. By identifying the musical product as a durable goods, we model the consumers’ consumption rule with forward-looking behaviour, viewing music streaming as the consumers’ option of delayed consumption, making purchase only when the expected discounted lifetime utility exceeds the expected utility from streaming. Our proposed decision support framework has the record label use both the price and advertising as instrument of control in achieving maximised expected discounted profit, playing strategically in anticipating to the consumers’ decisions using an interactive Markov chain. We show in our illustrative example the proposed decision support framework is able to make decisions dynamically and performs substantially better than other single control variable decision tools.

It is a well recognized understanding that workers whose voice needs to be heard should be actively encouraged as full participants and involved in the early design stages of new ergonomic work system which encompass the development and implementation of new tools, workplaces, technologies or organizations. This paper presents a novel participatory strategy to evaluate three key psychological factors which are respectively mental fatigue, spiritual stress, and emotional satisfaction in work system design based on a modified version of Participatory Ergonomics (PE). In specific, it integrates a PE technique with a formulation view by combining the parallel development of PE strategies, frameworks and functions throughout the coverage of the entire work system design process, so as to bridge the gap between qualitative and quantitative analysis of psychological factors which can cause adverse or advantageous effects on worker's physiological and behavioral performance.

The amount of active ingredient in 20 commercially sourced batches of praziquantel (PZQ) tablets was determined using a high-performance liquid chromatography-ultraviolet (HPLC-UV) assay in conjunction with an anthentic, lot of PZQ powder. The general composition of each batch of tablets was also examined by means of (1)H nuclear magnetic resonance (NMR) spectroscopy and the NMR data were subjected to pattern recognition analysis by means of principal component analysis. The HPLC-UV results showed that each batch of PZQ tablets contained approximately the required amount of PZQ (600 mg per tablet). The NMR analysis showed a high degree of compositional variation between manufacturers, which caused by variation in excipients, along with some batch-to-batch variation in the tablets from a single manufacturer. Additionally, the PZQ tablets from one manufacturer were found to have an extra component (methyl-4-hydroxybenzoate) that was not detected in the other preparations.

An effective system development paradigm and its associated design tools can streamline the production of flexible manufacturing systems. In view of the technological advances in developing complex manufacturing systems, a framework and its associated graphical development environment are presented in this paper. This framework aims at providing a unified platform to develop complex manufacturing systems with enhanced formality. Features include procedures for requirement analysis, simulation of system behavior, and formal verification of abstract implementation. The proposed framework helps to shorten lifecycle for system designs and helps engineers to produce manufacturing systems that conform better with original specifications with better quality. A flexible conveyor‐based production system is chosen as a case example to illustrate the capabilities of the proposed framework.

With the Bondi‐Metzner‐Sachs (BMS) group in general relativity as the main motivation and example, a theorem is proved which may be described as follows. Let G be a complex semisimple, connected and simply connected Lie group with compact real form K , and let A be a metrizable, complete and locally convex real topological vector space on which there is a continuous G action. Consider the semidirect product topological group Gx s A (which is, in general, infinite‐dimensional) constructed naturally out of G and A . If the set of equivalence classes of irreducible representations of K in A satisfies certain hypotheses, then the second cohomology group of G x s A in the sense of continuous group cohomology is trivial. When G = SL (2, C ) and A is an appropriate function space of real‐valued functions of the 2‐sphere endowed with a specific G action (e.g. A may consist of C k , k ⩾ 3, real‐valued functions defined on the 2‐sphere), the semidirect product group is the universal cover of the BMS group. The theorem implies the existence of lifting of the projective unitary representations of the BMS group to the linear unitary representations of its universal cover. In the quantum context when we consider massless quantum fields at null infinity of a non‐stationary, asymptotically Minkowskian space‐time, in place of the projective unitary representations of the BMS group, there is no loss of generality in considering the linear unitary representations of its universal cover instead.

Balloon mitral valvotomy (BMV) is safe and effective in patients with mitral stenosis (MS) and coexisting mild mitral regurgitation (MR). Influence of preexisting MR on late outcome of BMV is under evaluation. We included 77 patients without MR and 72 with MR in this study, and compared their immediate and late results in a mean follow-up of 33 ± 24 months after BMV. Patients with coexisting MR were older and more frequently had significant valvular calcium and atrial fibrillation than patients without MR. After BMV, mitral valve gradient decreased, and cardiac output and mitral valve area by planimetry increased significantly (all p = 0.0001) in both groups. There was no difference in values of mitral valve gradient and cardiac output after BMV between the groups. Mitral valve area was significantly smaller in patients with preexisting MR. During follow-up, there were 11 patients (14%) in the group without MR and 24 (33%) in the group with MR developed cardiac events (p = 0.006). Cumulative event-free survival was 90% at the second year, 87% at the fourth year, and 69% at the sixth year, respectively, in the group without MR versus 78%, 62%, and 37%, respectively, in the group with MR (p = 0.0014). Cox regression showed that preexisting MR was a significant predictor for late cardiac events with a threefold increased hazard risk (p = 0.0025), but age, valvular calcium, echocardiographic score, and cardiac rhythm also played a culpable role. We conclude that preexisting MR is an important risk factor for poor, late outcome of BMV.

We developed a prognostic scoring system to predict the outcome of follow-up after balloon mitral valvotomy. The system incorporates seven variables before valvotomy: age, New York Heart Association class, fluoroscopic calcification, echocardiographic score, cardiac rhythm, mitral regurgitation, and mitral valve area. Each variable was coded with either 0 or 1 and a total score was between 0 and 7. The study included 150 patients with a mean follow-up of 33 ± 24 months. In patients with scores of 0-1, 2-3, 4-5, and 6-7, the estimated cardiac event-free survival rate was 97%, 94%, 86%, and 68%, respectively, at 1 year; 95%, 88%, 74%, and 47%, respectively, at 3 years; and 92%, 82%, 61%, and 30%, respectively, 5 years after valvotomy ( p = 0.0001). The hazard risk ratio for cardiac events was 1.7 times greater for every step up of the score ( p = 0.0001). Our scoring system provides a simple but effective method to predict late outcome of balloon mitral valvotomy. (Am Heart J 1997;134:772-8.)

The follow-up results between Inoue balloon (n = 43, group 1) and double-balloon (n = 43, group 2) mitral valvotomies were compared in a patient-to-patient matched study. Matching was based on patients' age, mitral valve echo score, fluoroscopic calcification, mitral valve area before valvotomy, and follow-up period. The mean follow-up period was 13 +/- 9 months for both groups. At follow-up, 72% of patients were symptom free in each group; 2 (4.7%) patients in group 1 and 1 (2.3%) patient in group 2 underwent mitral valve replacement surgery. Of these 3 patients, 2 died after surgery, 1 from each group. The mitral valve area by Doppler was 1.8 +/- 0.3 cm2 in group 1 and 1.8 +/- 0.4 cm2 in group 2 (p = 0.7); the area by echo planimetry was 1.7 +/- 0.3 cm2 in group 1 and 1.8 +/- 0.3 cm2 in group 2 (p = 0.3) at follow-up. Restenosis occurred in 5 (12%) patients from each group. The cumulative restenosis-free rate was 96% at 1 years, 78% at 2 years, and 58% at 3 years in group 1 and 98%, 76%, and 51%, respectively, in group 2 (p = 0.8). Balloon selection did not appear to influence the clinical outcome at follow-up. We conclude that both the inoue balloon and the double-balloon valvotomies are effective therapies with comparable follow-up results for patients with mitral stenosis.

This study was conducted to establish the validity of left-sided cardiac output measurement with a Swan-Ganz catheter and assess its accuracy in estimating mitral valve area (MVA) by the Gorlin formula. The use of right-sided cardiac output after balloon mitral valvotomy (BMV) can give inaccurate measurements for Gorlin-derived MVA because of the atrial septal defect (ASD) created during the procedure. The left-sided cardiac output was measured with a Swan-Ganz catheter (proximal port in the left atrium and then in the left ventricle, and distal port in the ascending aorta) in 10 consecutive patients before and after BMV. Gorlin-derived MVA cardiac output by this method was compared with (1) Gorlin-derived MVA by means of right-sided cardiac output with and without balloon occlusion of the ASD and (2) MVA measured by echocardiography. Before BMV, a close agreement with a good correlation between left-sided and right-sided cardiac output was found (r = 0.83, p = 0.006). Furthermore, Gorlin-derived MVA by cardiac output with either method was comparable with valve area by echo. After BMV, left-sided cardiac output correlated well (r = 0.92, p = 0.0002) and was comparable with right-sided cardiac output with occlusion of the ASD (mean difference 0.17 +/- 0.49 L/min, p = 0.3) but was significantly lower than the value obtained with open ASD (mean difference 0.93 +/- 0.77 L/min, p = 0.004). Comparison of the correspondent MVAs yielded similar results. Gorlin-derived MVA with left-sided cardiac output and MVA by echo were also similar.(ABSTRACT TRUNCATED AT 250 WORDS)

The thermodynamic fluctuation near a certain critical temperature of an isolated, radiating Kerr-Newman black hole with charge and angular momentum not both zero is investigated. Divergence is found in the mean square fluctuation of mass and entropy of the black hole as the critical temperature is approached. This gives further support to the existence of a second order phase transition for Kerr-Newman black holes.

The thermodynamic fluctuation of a charged black hole is investigated and anomalous behaviour near a certain critical temperature is found, evidencing the existence of a phase transition. A phenomenological order parameter is then introduced and the fluctuation-dissipation properties of the black hole near the critical temperature are studied. The critical exponents of relevant thermodynamical quantities are also computed.

Resurgence of the transseptal procedure in the last decade has occurred coincident with the advent of therapeutic catheterizations and in particular mitral balloon valvuloplasty. As larger numbers of these procedures have been performed, experience shows that the position of intended septal puncture varies for each anticipated procedure and need not lie at the fossa ovalis, which is frequently displaced or inaccessible. Recognizing the dynamic alterations in septal and atrial anatomy that accompany the various combinations of valvular heart disease, the experienced interventionalist will use precatheterization echo and radiological techniques to enable precise and localized transseptal puncture. Using these techniques in 597 patients for valvular heart disease, we have had no deaths and a morbidity of 1.8% with the transseptal puncture. © 1992 Wiley-Liss, Inc.

Percutaneous double balloon valvotomy for severe rheumatic mitral stenosis was successfully performed in 281 of 285 consecutive patients. The changes evoked were a decrease of the mean transvalvular gradient from 16 +/- 7 to 5 +/- 3 mm Hg, an increase in cardiac output from 3.8 +/- 1.0 liters/min to 5.4 +/- 1.5 liters/min and an increase in mitral valve area from 0.86 +/- 0.24 cm2 to 2.41 +/- 0.54 cm2. The mean pulmonary artery pressure decreased from 37 +/- 13 mm Hg to 27 +/- 12 mm Hg and the pulmonary vascular resistance decreased from 307 +/- 181 to 238 +/- 122 dynes/s/cm-5. Symptomatic improvement occurred in 272 of the 285 (95%) patients. There were 3 procedure-related deaths (1%). Postdilatation mitral regurgitation was not significant in most patients. Therefore, this procedure can be performed at a low risk with effective results and a fast recovery.

The increasing interest in the Semantic Web is producing a growing number of publicly available domain ontologies. These ontologies are a rich source of information that could be very helpful during the process of engineering other domain ontologies. We present an automatic technique that, given a set of Web documents, selects appropriate domain ontologies from a collection of pre-existing ontologies. We empirically compare an ontology match score that is based on statistical techniques with simple keyword matching algorithms. The algorithms were tested on a set of 183 publicly available ontologies and documents representing ten different domains. Our algorithm was able to select the correct domain ontology as the top ranked ontology 8 out of 10 times.

The purpose of the investigation is to develop a prototype hybrid package to integrate an InGaAsP laser diode array with an array of waveguides on the Si optical bench (SiOB) using solder-bumped flip chip technology.

It is shown that a proposed dual-port DRAM approach for the realization of an orthogonal memory access structure is a very cost-effective method for digital signal processing. It has the advantages of flexibility and high-speed switching for time-domain real-time image processing. The authors also propose to use a dual-port DRAM in a FIFO form to obtain a processor-array extension scheme to extend logically the processor array to an infinite length. This gives a systematic solution to the job partitioning problem of multiprocessors for digital signal processing. It is also shown that various digital signal processing problems have been tackled successfully using the suggested processor-array extension and other techniques. The authors expect the proposed structure and realization schemes to be suitable for other applications. >

We present a patient with a left atrial hemangioma associated with shortness of breath and irregular heart-beats. Imaging modalities used to evaluate this rare tumor demonstrated characteristic features of its vascular nature. After successful surgical excision of the tumor under cardiopulmonary bypass, there were no clinical or echocardiographic evidence of recurrence at 18 months.

Balloon mitral valvotomy (BMV) provides improvement in pulmonary vascular resistance (PVR) in patients with severe mitral stenosis. Its normalization, however, remains questionable. We evaluated PVR before, after BMV, and at follow-up in 37 patients who had a previous successful BMV. Patients were divided into 2 groups: group 1 had 21 patients with normalized PVR (125 dynes/s/cm5) either after BMV or at follow-up, and group 2 had 16 patients with persistently abnormal PVR. Patients in group 2 were older than patients in group 1 (55+/-13 vs 43+/-14 years, p = 0.01) and had atrial fibrillation more frequently (10 [63%] vs 6 [29%], p = 0.04). Age, cardiac rhythm, mitral valve area, pulmonary bed gradient, pulmonary artery pressure, and PVR before the procedure were significant univariate predictors for normalization of PVR. Age, echocardiographic score, systolic pulmonary artery pressure, and mitral regurgitation were all independent determinants of normalization of PVR in a multivariate logistic regression model. We conclude that PVR failed to return to normal in 16 patients (43%) after successful BMV; this can be predicted by baseline clinical and hemodynamic parameters.

The influence on a quantum scalar field in its Minkowski vacuum state induced by weak coupling of the field to a uniformly accelerated harmonic oscillator is studied. From the perspective of a Rindler observer, the reaction of the oscillator on the quantum field distorts the Planckian particle spectrum of the Minkowski vacuum state and induces a change of state for the quantum field even without simultaneous excitation of the oscillator. From the perspective of an inertial observer, apart from inducing the excitation of a Minkowski vacuum state without excitation of the oscillator, the reaction of the oscillator on the field also gives rise to the presence of particles in the Minkowski vacuum state. In the long time limit, when the oscillator comes into thermal equilibrium again with the Minkowski vacuum state according to a Rindler observer, a closed expression for the particle number is worked out and its physical implications are discussed. EPR correlation of the Minkowski vacuum state for a Rindler observer is also disturbed by the presence of an accelerated oscillator even in the long time limit. When the oscillator is viewed as a simple model of a measuring device, the result suggests that noise induced by measurementmore » on a quantum field might present difficulties for a Rindler observer who wants to uphold EPR correlation across the event horizon. {copyright} {ital 1996 The American Physical Society.}« less

In summary, the possibility of developing moderate to severe (3+) MR after balloon dilatation was greater in patients with preexisting moderate MR. Nevertheless, improvements in hemodynamics and increases in mitral valve area can be equally achieved using balloon mitral valvotomy for treatment of mitral stenosis in patients with or without moderate MR.

We assessed immediate and late outcome in 55 patients with significantly calcified valves (group 1) after balloon mitral valvotomy and compared the results with those from 60 patients with noncalcified or minimally calcified valves (group 2). After valvotomy, mitral valve area increased from 1.03 +/- 0.30 cm2 to 1.64 +/- 0.35 cm2 (p = 0.0001) by echo planimetry in group 1 but was significantly smaller than the mitral valve area in group 2 after valvotomy (1.94 +/- 0.38 cm2; p = 0.0001). At a mean follow-up period of 30 months (range 2 to 81 months), 51% of patients in group 1 and 83% in group 2 were symptom free (p = 0.0002). In group 2, 15 (27%) patients and in group 2, 4 (7%) patients had cardiac events (p = 0.003). The risk ratio for cardiac events was 4.3 times greater in group 1 than in group 2. In group 1, the risk ratio for cardiac events was 3.2 times higher in patients age > or = 65 years and in patients with atrial fibrillation. The 6-year cumulative cardiac event-free survival rate was 64% in group 1 and 90% in group 2 (p = 0.005). In 75 (65%) patients who had follow-up echocardiographic study (35 in group 1 and 40 in group 2), mitral valve area decreased to 1.48 +/- 0.42 cm2 at follow-up in group 1 (p < 0.01) and to 1.77 +/- 0.50 cm2 in group 2 (p = 0.3). Restenosis occurred in 16 (46%) of 35 patients in group 1 and 10 (25%) of 40 in group 2 (p = 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

We adopt the concept of using pheromones to generate a set of static paths that can reach the performance of global dynamic routing strategy [Phys. Rev. E 81 (2010) 016113]. The path generation method consists of two stages. In the first stage, a pheromone is dropped to the nodes by packets forwarded according to the global dynamic routing strategy. In the second stage, pheromone static paths are generated according to the pheromone density. The output paths can greatly improve traffic systems' overall capacity on different network structures, including scale-free networks, small-world networks and random graphs. Because the paths are static, the system needs much less computational resources than the global dynamic routing strategy.

This is a 43-yr-old female presenting with recurrent atrial septal defect, closed surgically, 10 years prior, severe aortic and mitral stenosis, and severe tricuspid regurgitation. She was considered inoperable because of the severe pulmonary hypertension and the complexity of the disease. A percutaneous umbrella closure of the atrial septal defect in conjunction with mitral and aortic balloon valvotomies could be safely and successfully performed. After significant clinical and hemodynamic improvement, surgery was judged feasible, but was refused by the patient who suddenly expired 8 weeks later. The usefulness of percutaneous therapy as a rescue procedure and the management of patients with Eisenmenger's physiology are discussed.

The results of percutaneous mitral valvotomy by means of the lnoue single-balloon (N = 85, group 1) and the double-balloon (N = 322, group 2) techniques were compared in a nonrandomized study. The groups were not significantly different with regard to age, sex, calcification, or hemodynamic values before percutaneous mitral valvotomy. After percutaneous mitral valvotomy, patients in both groups had significant hemodynamic and clinical improvement. The increases in mitral valve area and cardiac output and the decreases in mitral valve gradient, mean pulmonary artery pressure, and mean left atrial pressure were greater in group 2. Mitral valve area determined by the Gorlin method increased 191% in group 2 and 106% in group 1; Doppler-determined mitral valve area increased 133% in group 2 and 98% in group 1. Optimal results were achieved in 93% of the patients in group 2 and 76% in group 1 (p ≤ 0.0001). In group 1, 6% of patients had a left-to-right shunt as shown by angiography versus 14% in group 2 (p ≤ 0.05). In group 2, 46% of patients had at least a 1 + increase in mitral regurgitation versus 52% in group 1. Among the patients who had an increase in mitral regurgitation, 36% of those in group 1 versus 9% in group 2 had a 2+ or more increase (p ≤ 0.001). The mean balloon diameter to anulus ratio was larger in group 2, and the larger the balloon diameter to anulus ratio, the greater the increase in mitral valve area. Long-term follow-up will be needed to determine whether or not the immediate hemodynamic superiority of the double-balloon technique is clinically important.

A patient with progressive disabling angina was found to have a single right coronary artery with atresia of the left main coronary artery, and absence of any obstructive coronary disease. The patient required aortocoronary by-pass surgical reconstruction of a left main coronary artery to control her angina. Possible mechanisms for the development of her anginal pain are briefly discussed.