Extrahepatic complications of liver transplantation.

The massive surgical assault associated with hepatic transplantation makes a high frequency of complications almost inevitable. In this review of 225 patient records, selected at random from cases of liver transplantation in Pittsburgh over a 2 1/2 year period ending in January 1985, 87.2% of patients experienced at least one significant complication that threatened their survival or that of the graft and that often prolonged their hospitalization. Familiarity with the complications may facilitate earlier recognition, with consequently early and more effective management in future cases

A simplified technique for the treatment of simple pleural effusions

This technique for the drainage of simple pleural effusions is simple, safe and effective. It requires little more skill than the ability to perform a thoracentesis or central venous line placement. It appears ideal for both the bedridden patient who cannot sit for repetitive thoracocentesis and for the ambulatory patient who need not be tied down with a chest tube and underwater seal system. We stress that the system is functional only for simple transudates and will provide unsatisfactory drainage of thick or bloody effusions

Influence of selected patient variables and operative blood loss on six-month survival following liver transplantation.

A group of 118 adults who underwent primary, orthotopic transplantation of the liver over a 4-year period served as the subjects of a detailed examination of their ability to survive the first 6 months as a function of their preoperative condition. As a result, a scoring system was developed empirically in an attempt to separate very high-risk from relatively low-risk patients. The scoring method is based on the high degree of correlation between survival probability and various patient characteristics. It allows for additional scoring to account for the dramatic effect of operative blood loss on the eventual outcome. The curve that best describes the relationship between patient scores and survival probability is sigmoidal in shape. Many patients will have scores located on the curve between the inflection points. They represent a group whose relative risk is difficult to estimate but for whom operative blood loss or the occurrence of surgical complications may prove particularly telling

Does Associative Memory Play a Role in Solving Physics Problems?

This is the final version of the article. Available from the publisher via the link in this record.Previous research has found that people frequently provide incorrect predictions about the path of moving objects when given an idealised physics problem to solve. The aim of this research was to explore whether these incorrect predictions are due to the application of an incorrect naïve physics theory, whether incorrect perceptions generated from past experiences lead to misconceptions of how moving objects behave, or whether it is a combination of both. Thirty-one participants volunteered to take part in the experiment which followed a two (experience congruent/incongruent with naïve physics theory) by two (carried versus free-moving object) within-subject design. The dependent variable was participant response (straight down or curved forwards). Results of the study revealed that participants provided answers both consistent and inconsistent with the naïve physics theory. This suggests that responses were primarily elicited through the retrieval of associatively-mediated memories of similar scenarios - some of which contain perceptual illusions. Possible methodological limitations and alternative theoretical explanations are discussed, along with practical and theoretical implications for education and learning

Naïve Physics - the wrong theory?

PublishedCopyright © 2013 Cognitive Science SocietyIn this paper we examine the idea of a "naïve physics" in humans solving physics problems. This invokes the idea that people have a theory of motion in their heads that is non- Newtonian, and hence leads to systematic errors on these problems. We are able to show that, by selecting our problems carefully, it is possible to obtain answers that are consistent with this naïve physics and inconsistent with it; suggesting that it is not used to solve these problems but sometimes offered as post-hoc justification for the answers given. We offer evidence that the answers given owe more to past experience than any theory, and that a theory that postulates extrapolation on the basis of associative memory can give a good account of our results

Across the great divide: genetic forensics reveals misidentification of endangered cutthroat trout populations

Accurate assessment of species identity is fundamental for conservation biology. Using molecular markers from the mitochondrial and nuclear genomes, we discovered that many putatively native populations of greenback cutthroat trout (Oncorhynchus clarkii stomias) comprised another subspecies of cutthroat trout, Colorado River cutthroat trout (Oncorhynchus clarkii pleuriticus). The error can be explained by the introduction of Colorado River cutthroat trout throughout the native range of greenback cutthroat trout in the late 19th and early 20th centuries by fish stocking activities. Our results suggest greenback cutthroat trout within its native range is at a higher risk of extinction than ever before despite conservation activities spanning more than two decades

The Evolving Landscape of the Economics of HIV Treatment and Prevention

Bohdan Nosyk and Julio Montaner argue that the cost-effectiveness of HAART roll out has been significantly underestimated because economic analyses haven't yet taken into account the beneficial impact of HAART on HIV transmission

A novel pathway producing dimethylsulphide in bacteria is widespread in soil environments

The volatile compound dimethylsulphide (DMS) is important in climate regulation, the sulphur cycle and signalling to higher organisms. Microbial catabolism of the marine osmolyte dimethylsulphoniopropionate (DMSP) is thought to be the major biological process generating DMS. Here we report the discovery and characterisation of the first gene for DMSP-independent DMS production in any bacterium. This gene, mddA, encodes a methyltransferase that methylates methanethiol (MeSH) and generates DMS. MddA functions in many taxonomically diverse bacteria including sediment-dwelling pseudomonads, nitrogen-fixing bradyrhizobia and cyanobacteria, and mycobacteria, including the pathogen Mycobacterium tuberculosis. The mddA gene is present in metagenomes from varied environments, being particularly abundant in soil environments, where it is predicted to occur in up to 76% of bacteria. This novel pathway may significantly contribute to global DMS emissions, especially in terrestrial environments, and could represent a shift from the notion that DMSP is the only significant precursor of DMS

Loss to follow-up in a community clinic in South Africa – roles of gender, pregnancy and CD4 count

Background. Faith-based organisations have expanded antiretroviral therapy (ART) in community clinics across South Africa. Loss to follow-up (LTFU), however, limits the potential individual and population treatment benefits and optimal care. Objective. To identify patient characteristics associated with LTFU 6 months after starting ART in a large community clinic. Methods. Patients initiating ART between April 2004 and October 2006 in one South African Catholic Bishops’ Conference HIV treatment clinic who had at least one follow-up visit were included and routinely monitored every 6 months after ART initiation. Standardised instruments were used to collect data. Rates of LTFU over time were estimated by the Kaplan-Meier method. The Cox proportional hazard regression examined the impact of age, baseline CD4 count, baseline HIV RNA, gender and pregnancy status on LTFU. Results. Data from 925 patients (age >14 years, median age 36 years, 70% female, of whom 16% were pregnant) were included: 51 (6%) were lost to follow-up 6 months after ART initiation. Younger age (≤30 years) (hazard ratio (HR) 2.14, 95% confidence interval (CI) 1.05 - 4.38) and pregnancy for women (HR 3.75, 95% CI 1.53 - 9.16) were significantly associated with higher LTFU rates. When stratified by baseline CD4 count, gender and pregnancy status, pregnant women with lower baseline CD4 counts (≤200 cells/ μl) had 6.06 times the hazard (95% CI 2.20 - 16.71) of LTFU at 6 months compared with men. Conclusions. HIV-infected pregnant women initiating ART were significantly more likely to be lost to follow-up in a community clinic in South Africa. Urgent interventions to successfully retain pregnant women in care are needed