Relationship of body condition score and blood urea and ammonia to pregnancy in Italian Mediterranean buffaloes

The relationship of body condition score ( BCS) and blood urea and ammonia to pregnancy outcome was examined in Italian Mediterranean Buffalo cows mated by AI. The study was conducted on 150 buffaloes at 145 +/- 83 days in milk that were fed a diet comprising 14.8% crude protein, 0.9 milk forage units . kg(-1) dry matter and a non- structural carbohydrate/ crude protein ratio of 2.14. The stage of the oestrous cycle was synchronised by the Ovsynch- TAI programme and blood urea and ammonia levels were assessed on the day of AI. Energy corrected milk ( ECM) production and BCS were recorded bi- weekly. The pregnancy risk was 46.7% and was slightly lower in buffaloes with BCS < 6.0 and BCS > 7.5. There were no significant differences in ECM, urea and ammonia between pregnant and non- pregnant buffaloes. However, pregnancy outcome was higher ( P = 0.02) in buffaloes with blood urea < 6.83 mmol . L-1. The likelihood of pregnancy for buffaloes with low urea blood level was 2.6 greater than for high urea level and exposure to a high urea level lowered the probability of pregnancy by about 0.25. The findings indicate that buffaloes are similar to cattle and increased blood levels of urea are associated with reduced fertility when animals are mated by AI.

Evaluation of resynchronization of contractile function following biventricular pacing using colour tissue Doppler imaging

Biventdcular (BV) pacing is evaluated as an alternative treatment for patients with dilated cardiomyppathy (both ischemic and non-ischemic) and end-stage heart failure. Colour tissue Doppler imaging using echocardiography allows noninvasive, quantitative assessment of radial motion in the long-axis with measurement of peak systolic velocity timing. The aim of the present study was to evaluate quantitatively, the systolic performance of the left ventricle and the resynchrenization of contraction (before vs after implantation). Patients and methods: 25 patients with dilated cardiomyopathy (11 ischemic), NYHA class III or IV, QRS duration >120 ms received a biventricular pacemaker. Routine 2D echo and colour tissue Doppler imaging were performed before and within 1 week following implantation. LVEF was assessed using the biplane Sampson's method.Peak systolic velocity (PSV) and time to PSV (TPV) were assessed in 4 regions (basal anterior, inferior, lateral and septal). By averaging the TPV from all 4 regions, a synchronization index was dedved from these measurements. Reaults: LVEF improved by 9±9% following pacing; 17 patients improved LVEF 5% or more. The change in PSV in the septal and lateral regions related significantly to the change in LVEF (r=0.74, r=0.62).The change in synchronization index before vs after pacing (as a measurement of REsynchronization) was related to the change in LVEF (y=120x+5.6, r=0.79, P

Emergent temporal behaviour and collaborative work

Although collaboration manifestly takes place in time, the role of time in shaping the behaviour of collaborations, and collaborative systems, is not well understood. Time is more than clock-time or the subjective experience of time; its effects on systems include differential rates of change of system elements, temporally non-linear behaviour and phenomena such as entrainment and synchronization. As a system driver, it generates emergent effects shaping systems and their behaviour. In the paper we present a systems view of time, and consider the implications of such a view through the case of collaborative development of a new university timetabling system. Teasing out the key temporal phenomena using the notion of temporal trajectories helps us understand the emergent temporal behaviour and suggests a means for improving outcomes.

Refinement-robust fairness

We motivate and study the robustness of fairness notions under refinement of transitions and places in Petri nets. We show that the classical notions of weak and strong fairness are not robust and we propose a hierarchy of increasingly strong, refinement-robust fairness notions. That hierarchy is based on the conflict structure of transitions, which characterizes the interplay between choice and synchronization in a fairness notion. Our fairness notions are defined on non-sequential runs, but we show that the most important notions can be easily expressed on sequential runs as well. The hierarchy is further motivated by a brief discussion on the computational power of the fairness notions.

Modelling Java concurrency with Object-Z

In this paper, we present a formal model of Java concurrency using the Object-Z specification language. This model captures the Java thread synchronization concepts of locking, blocking, waiting and notification. In the model, we take a viewpoints approach, first capturing the role of the objects and threads, and then taking a system view where we capture the way the objects and threads cooperate and communicate. As a simple illustration of how the model can, in general be applied, we use Object-Z inheritance to integrate the model with the classical producer-consumer system to create a specification directly incorporating the Java concurrency constructs.

A classification of concurrency failures in java components

The Java programming language supports concurrency. Concurrent programs are hard to test due to their inherent non-determinism. This paper presents a classification of concurrency failures that is based on a model of Java concurrency. The model and failure classification is used to justify coverage of synchronization primitives of concurrent components. This is achieved by constructing concurrency flow graphs for each method call. A producer-consumer monitor is used to demonstrate how the approach can be used to measure coverage of concurrency primitives and thereby assist in determining test sequences for deterministic execution.