On the Feasibility of Extending Social Experiments to Wider Applications

Background: When deciding how to allocate limited funds for social programs, policymakers and program managers increasingly ask for evidence of effectiveness based on studies that rely on solid methodology, providing credible scientific evidence. The basic claim for the “social experiment”—that the “coin flip” of randomization creates two statistically equivalent groups that do not diverge except through an intervention’s effects—makes resulting estimates unbiased. Despite the transparency and conceptual strength of the experimental strategy for revealing the causal connection between an intervention and the outcomes of its participants, the wisdom or feasibility of conducting social experiments is often questioned on a variety of grounds. Purpose: This article defines 15 common concerns about the viability and policy reliability of social experiments, in order to assess how much these issues need constrain the use of the method in providing policy evidence. Setting: NA Intervention: NA Research Design: The research uses the authors’ experience designing and conducting dozens of social experiments to examine the basis for and soundness of each concern.  It  provides examples from the scholarly literature and evaluations in practice of both the problems posed and responses to each issue. Data Collection and Analysis: NA Findings: We conclude that none of the 15 concerns precludes substantially extending the use of randomized experiments as a means of evaluating the impacts of government and foundation social policies and programs

The joint US/UK 1990 epoch world magnetic model

A detailed summary of the data used, analyses performed, modeling techniques employed, and results obtained in the course of the 1990 Epoch World Magnetic Modeling effort are given. Also, use and limitations of the GEOMAG algorithm are presented. Charts and tables related to the 1990 World Magnetic Model (WMM-90) for the Earth's main field and secular variation in Mercator and polar stereographic projections are presented along with useful tables of several magnetic field components and their secular variation on a 5-degree worldwide grid

High Prevalence of Non-Typhoid Salmonella Bacteraemia Among Febrile HIV Adult Patients Admitted at a Tertiary Hospital, North-Western Tanzania.

Bacterial blood stream infections constitute a significant public-health problem and it is an important cause of morbidity and mortality in HIV infected patients. Little is known in developing countries regarding salmonella bacteraemia among HIV patients. The purpose of this study was to determine the bacterial pathogens causing blood stream infection among febrile adults attending in a tertiary hospital North-Western, Tanzania. A prospective cross-sectional study involving 346 consecutive, febrile adult patients admitted at Bugando Medical Centre was conducted. Demographic and other data were collected using standardized questionnaires. Blood culture was done followed by susceptibility testing using disc diffusion method. HIV testing was also performed as per Tanzania national algorithm and total white blood cell counts and CD4+ counts determined. Of 346 febrile adult patients 33 (9.5%) had blood stream infections. The common isolates were Salmonella spp 13(39.4%), Escherichia coli 8 (24.2%), Streptococcus pneumonia 5(15.2%), Staphylococcus aureus 4(12.1%), Citrobacter spp 1(3%), Streptococcus pyogenes 1(3%) and Klebsiella pneumonia 1(3%). A total of 156 (45.1%) patients were HIV infected; of whom 12/156 (7.6%) were infected by non-typhoid Salmonella spp compared to 1/190 (0.5%) of non-HIV infected patients (RRR 11.2, p=0.029) infected with Salmonella typhi. HIV infected patients with bacteraemia had significantly lower CD4+ count than those without bacteraemia (median 28 vs. 88 cells/ml, p=0.01). Patients with salmonella bacteraemia had significantly lower median of WBC than those with non-salmonella as well as those without bacteraemia (median, 3.6 vs. 17.5 vs. 9.8x109, p=0.0001). All Salmonella spp were sensitive to ceftriaxone and imipenem, while being 84%, 69.2%, 38% and 8% resistant to chloramphenicol, ampicillin, sulphamethaxazole/trimethoprim and ciprofloxacin respectively. Predictors of mortality were HIV infection (OR 2.3, p=0.006), Glasgow coma score of less than 15 (OR 3.4, p=0.0001) and night sweats (OR 2.4, p=0.014). Non-typhoid Salmonella spp that are highly resistant to common antibiotics are predominant cause of bacterial blood stream infection among HIV patients attending Bugando Medical Centre. Continuous surveillance and intervention strategies should be put in place to monitor and manage cases of bloodstream infections in HIV-positive patients in Mwanza, Tanzania

Alveolar Ridge Preservation Using Leukocyte and Platelet-Rich Fibrin: A Report of a Case

In order for a dental implant to be restored optimally, it must be placed in an ideal anatomic position. However, this is not always possible, since physiological wound healing after tooth removal, often results in hard and soft tissue changes which ultimately compromises ideal implant placement. With the aim of minimising the need for tissue augmentation, several alveolar ridge preservation (ARP) techniques have been developed. These often require the use of grafting material and therefore increase the risk of disease transmission. Leukocyte and platelet-rich fibrin (L-PRF) is a newly developed platelet concentrate that is prepared from the patient's own blood. Clinical research has indicated that it improves wound healing and stimulates bone formation. We present a case where L-PRF was successfully used in an ARP procedure to facilitate implant placement in a compromised extraction socket

Afterschool quality

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110030/1/yd20111.pd

Using Prediction to Improve Patient Flow in a Health Care Delivery Chain

Often, in a health care delivery chain, lack of coordination has been detrimental to timely, high quality care. This paper focuses on the two steps of the hospital health care delivery chain, an emergency department and a hospital’s inpatient units. Past research into this chain has suggested that early prediction of patient need for admission can be used to better align flow between the two departments. This chain and the nature of prediction in health care delivery are discussed as well as a how prediction may be useful in this context. Finally tools for making admission predictions are tested and their possible implications are explored. The results of this exploration show that both expert opinion and a Naïve Bayesian statistical approach have predictive value in this context

Liquid Phase Electrochemistry at Ultralow Temperatures

Fluid electrolyte solutions based on mixtures of butyronitrile (PrCN) and ethyl chloride (EtCl) with or as electrolyte freeze below −180°C and provide excellent media for cryogenic electrochemical experiments. A 1:2 mixture of PrCN and EtCl exhibits the best combination of freezing point and ionic conductivity for ultralow temperature electrochemistry. Diffusion coefficients for bis(pentamethylcyclopentadienyl) iron are measurable by potential step chronoamperometry down to −160°C using a conventionally sized electrode, but the resistivity of the solvent mixture is such that potential sweep voltammetry benefits from the use of microdisk (10 and 25 μm diam Pt) or microband (0.2 μm wide Au) electrodes. Voltammetry at a chemically modified electrode down to −170°C is presented for the case of thin films