Acute complete heart block in dogs

A study has been conducted immediately and up to 18 days after the surgical production of complete heart block in dogs. Immediately after surgery cardiac output, coronary flow, and mean arterial pressure were reduced in rough proportion to the degree of bradycardia. In time, these measures began to return toward preoperative levels. Paralleling the diminished left ventricular work was a diminished left ventricular oxygen consumption with little consequent change in myocardial efficiency. Small rises were detected in central venous pressure. At autopsy, the only unequivocal abnormality was myocardial hypertrophy which became measurable between 2 and 18 days after operation

Review of Community Seed Production Practices in Africa Part 2: Lessons Learnt and Future Perspective

Within the context of the case studies presented, there are clear lessons learned and the second section of the review (Part 2) draws out those lessons in looking at seed and variety, description of community seed production, the support role of public, private, and civil society actors, the role of subsidies and technical support, farm level impact, and sustainability. A general theme running through all of these case studies is improving farmers’ access to quality seed of desired varieties. Topics include varietal identification, seed production, seed quality, seed policy, and seed marketing. The main conclusions are: Community seed production is necessary to improve formal and farmer seed system links; community seed production objectives should be explicit and include coherent activities for closing out, transitioning into commercial entities, or linking with publicly funded programs; community seed production is more effective when there is strong collaboration between the public sector, the commercial sector, and civil society/NGOs; The lack of standard ex-ante seed system diagnostics, including economic analysis to justify the scale and scope of interventions, significantly limits the capacity of donors and seed practitioners to make rational investments and intervention design decisions

Traditional Open-bay Versus Single-family Room Neonatal Intensive Care Unit: a Comparison of Selected nutrition Outcomes

Background: In contrast to the traditional open-bay–type design of the neonatal intensive care unit (tNICU), infants in developmentally appropriate NICU (dNICU) are housed in individual rooms with greater control of light and noise. Previous reports have documented positive influence of the dNICU in cardiorespiratory status, physiologic stability, and weight gain of the infants. The objective of this study was to explore selected nutrition outcomes of infants in the dNICU versus tNICU. Method: A prospective cohort study was conducted on infants with birth weight of 1500 g or less cared for in dNICU (n = 42) or tNICU (n = 31). Differences between days to reach full parenteral nutrition, full enteral nutrition, or full bottling were determined using analysis of covariance controlling for gestational age, birth weight, and clinical risk index for babies (CRIB) acuity score. Results: There were no differences between the two groups in days to reach full parenteral and bottle feeding. The infants in the dNICU took fewer days to reach full enteral nutrition (20.8 days, 95% confidence intervals [CI]: 17, 24.6 (dNICU) vs 23.3 days, 95% CI: 17.1, 29.6 (tNICU), P = 0.04) than those in the tNICU. Conclusions: Although the two groups of infants only differed in the days to reach full enteral feeding, it is important to remember that the lack of difference may be clinically significant. Clinically, the infants in the dNICU were younger (gestational age) and sicker (CRIB acuity score) than the infants in the tNICU. Consequently, the results of this study support the change to dNICU, as the private room model provides a supportive environment for growth as evidenced by similar nutritional outcome measures. More research is needed to determine the effect of the dNICU on nutrition outcomes

The time scale for the transition to turbulence in a high Reynolds number, accelerated flow

An experiment is described in which an interface between materials of different density is subjected to an acceleration history consisting of a strong shock followed by a period of deceleration. The resulting flow at this interface, initiated by the deposition of strong laser radiation into the initially well characterized solid materials, is unstable to both the Richtmyer–Meshkov (RM) and Rayleigh–Taylor (RT) instabilities. These experiments are of importance in their ability to access a difficult experimental regime characterized by very high energy density (high temperature and pressure) as well as large Reynolds number and Mach number. Such conditions are of interest, for example, in the study of the RM/RT induced mixing that occurs during the explosion of a core-collapse supernova. Under these experimental conditions, the flow is in the plasma state and given enough time will transition to turbulence. By analysis of the experimental data and a corresponding one-dimensional numerical simulation of the experiment, it is shown that the Reynolds number is sufficiently large (Re>105)(Re>105) to support a turbulent flow. An estimate of three key turbulence length scales (the Taylor and Kolmogorov microscales and a viscous diffusion scale), however, shows that the temporal duration of the present flow is insufficient to allow for the development of a turbulent inertial subrange. A methodology is described for estimating the time required under these conditions for the development of a fully turbulent flow. © 2003 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70243/2/PHPAEN-10-3-614-1.pd

Process cost analysis for the optimization of a container-based sanitation service in Haiti

A process cost analysis methodology was developed to calculate the per capita operational costs of the container-based sanitation service in Haiti operated by the non-profit research and development organization Sustainable Organic Integrated Livelihoods (SOIL). SOIL’s sanitation service covers the entire sanitation value chain, including containment, collection, transport, treatment and reuse. The results showed that around 30% of the service’s operational costs were covered with operating revenue. The researchers then used the detailed results to identify productive areas for cost reduction and further innovation. Findings also contributed to the development of a hybrid funding model that will enable increased access to sanitation while building relationships with public institutions and reinforcing a business mindset to encourage cost-effectiveness with scale