Impact of fuel quality regulation and speed reductions on shipping emissions: implications for climate and air quality

Atmospheric emissions of gas and particulate matter from a large ocean-going container vessel were sampled as it slowed and switched from high-sulfur to low-sulfur fuel as it transited into regulated coastal waters of California. Reduction in emission factors (EFs) of sulfur dioxide (SO?), particulate matter, particulate sulfate and cloud condensation nuclei were substantial (≥ 90%). EFs for particulate organic matter decreased by 70%. Black carbon (BC) EFs were reduced by 41%. When the measured emission reductions, brought about by compliance with the California fuel quality regulation and participation in the vessel speed reduction (VSR) program, are placed in a broader context, warming from reductions in the indirect effect of SO? would dominate any radiative changes due to the emissions changes. Within regulated waters absolute emission reductions exceed 88% for almost all measured gas and particle phase species. The analysis presented provides direct estimations of the emissions reductions that can be realized by California fuel quality regulation and VSR program, in addition to providing new information relevant to potential health and climate impact of reduced fuel sulfur content, fuel quality and vessel speed reductions.     

Individual risk factors for hip osteoarthritis: obesity, hip injury, and physical activity

Hip osteoarthritis is a major cause of pain and disability. The authors explored individual risk factors for hip osteoarthritis in a population-based case-control study. The study was performed in two English health districts (Portsmouth and North Staffordshire) from 1993 to 1995. A total of 611 patients (210 men and 401 women) listed for hip replacement because of osteoarthritis over an 18-month period were compared with an equal number of controls selected from the general population and individually matched for age, sex, and family practitioner. Information about suspected risk factors was obtained by a questionnaire administered at interview and a short physical examination. Obesity (odds ratio (OR) = 1.7, 95% confidence interval (CI) 1.3-2.4; highest vs. lowest third of body mass index), previous hip injury (OR = 4.3, 95% CI 2.2-8.4), and the presence of Heberden's nodes (OR = 1.6, 95% CI 1.2-2.2) were independent risk factors for hip osteoarthritis among men and women. Hip injury was more closely related to unilateral as compared with bilateral disease. There were a negative association between cigarette smoking and osteoarthritis among men and a weak positive association with prolonged regular sporting activity. Obesity and hip injury are important independent risk factors for hip osteoarthritis, which might be amenable to primary prevention. Hip osteoarthritis may also arise as part of the polyarticular involvement found in generalized osteoarthritis.     

Ultrasonographic estimate of birth weight at 24 to 34 weeks: a multicenter study

OBJECTIVE: The study was intended to compare the accuracies of ultrasonographic estimates of birth weights among infants born between 24 and 34 weeks' gestation at 3 tertiary centers. STUDY DESIGN: In this retrospective study subjects were matched for gestational age (1:1); all underwent ultrasonographic examination within 2 weeks of delivery. The estimates of birth weight were obtained according to 26 published regression equations and their accuracies were assessed with the mean standardized absolute error. For each center the equation with the lowest error was selected to generate (1) receiver-operating characteristic curves for an estimate to identify actual weight < 1500 g and (2) prediction limit calculations to determine the estimate that ensures at 70% confidence a birth weight > 1500 g. RESULTS: One hundred seventy-one cases were analyzed at each center. Comparison of the 26 mean standardized errors at each center indicated that (1) the range was rather wide (eg, 89 +/- 87 to 365 +/- 313 g/kg) and (2) 73% (19/26) of the equations had significantly (P < .05) different accuracies. Receiver-operator characteristic curves show that fetal weight estimates of > or = 1600 g at 2 centers and > or = 1700 g at the third center are required to predict actual birth weight < 1500 g. Prediction limit calculation suggests that different fetal weight estimates (> 1600 g at center 1, > 1900 g for the center II, and > 1800 g at center III) are needed to predict actual weight > 1500 g with a 70% accuracy. CONCLUSIONS: Ultrasonographic estimates of weight for preterm infants, as obtained from 26 equations, are characterized by a rather wide range of accuracy; for most of the equations the accuracies of estimates differ markedly among centers.     

Genetics and human reproduction

Most people want children, and most people want healthy children. For those couples with an infertility problem who have recourse to assisted reproduction, usually in vitro fertilization (IVF) or donor insemination (DI), the practitioners have a special responsibility to ensure as far as possible that the babies in whose conception they assist are in good health. How can they best tackle the challenge of inherited diseases, of which about 4000 are known today, and chromosomal malfunction?     

Blocking and Unblocking in Human Causal Learning.

Three experiments sought to develop the suggestion that, under some circumstances, common associative learning mechanisms might underlie animal conditioning and human causal learning, by demonstrating, in humans, an effect analogous to the unblocking by reinforcer omission observed in animal conditioning. Experiment 1 found no such effect. Experiment 2, designed to prevent inhibitory influences that might have masked excitatory unblocking in Experiment 1, demonstrated unblocking, indicating common human-animal associative learning mechanisms in which the associability of a stimulus varies as a function of its predictive history. Experiment 3, using a similar design but with a procedure promoting application of rational inference processes, failed to detect the same unblocking effect, indicating that associative and cognitive mechanisms may influence human causal learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Localization of HRG4, a photoreceptor protein homologous to Unc-119, in ribbon synapse

PURPOSE: To characterize further HRG4, a novel photoreceptor protein recently identified by subtractive cDNA cloning, by sequence analysis and immunolocalization. METHODS: The rat homolog of HRG4, RRG4 was expressed and used to prepare an antibody. The antibody was used in Western blot analysis, and immunofluorescent localization at the light and electron microscopic levels of HRG4-RRG4 protein. The HRG4-RRG4 sequence was also analyzed for homologies. RESULTS: HRG4-RRG4 showed 57% homology with unc-119, a Caenorhabditis elegans neuroprotein causing defects in locomotion, feeding, and chemosensation when mutated. By Western blot analysis, the HRG4-RRG4 protein was demonstrable only in retina and was soluble in nature. Immunofluorescence microscopic study of human and rat retinas, using the HRG4-RRG4 antibody, and other rod and cone photoreceptor-specific antibodies showed that the HRG4-RRG4 protein is localized in the outer plexiform layer of the retina in the synaptic termini of rod and cone photoreceptors. Electron microscopic immunolocalization showed the protein in the cytoplasm and on the presynaptic membranes of the photoreceptor synapses. CONCLUSIONS: The homology to unc-119 and localization to the photoreceptor synapse are suggestive of a function for HRG4-RRG4 in photoreceptor neurotransmission. HRG4 is the first photoreceptor-enriched synaptic protein to be reported, suggesting that its function may be unique to the specialized ribbon synapses formed between photoreceptors and the horizontal and bipolar cells of the retina.     

The Outcome Specificity of Learned Predictiveness Effects: Parallels Between Human Causal Learning and Animal Conditioning.

Two experiments examined the outcome specificity of a learned predictiveness effect in human causal learning. Experiment 1 indicated that prior experience of a cue-outcome relation modulates learning about that cue with respect to a different outcome from the same affective class but not with respect to an outcome from a different affective class. Experiment 2 ruled out an interpretation of this effect in terms of context specificity. These results indicate that learned predictiveness effects in human causal learning index an associability that is specific to a particular class of outcomes. Moreover, they mirror demonstrations of the reinforcer specificity of analogous effects in animal conditioning, supporting the suggestion that, under some circumstances, human causal learning and animal conditioning reflect the operation of common associative mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discrimination and generalization along a simple dimension: Peak shift and rule-governed responding.

In 2 experiments, participants learned to discriminate between a pair of simply related, but very similar, colors in a 2-choice categorization task. They were then tested over a wider range of isoluminant hues. Over these test values, both experiments yielded a postdiscrimination gradient that was initially peak-shifted but became monotonic through the course of testing. In Experiment 2, the presence of this early peak shift and subsequent change in gradient form were related to participants’ inability to verbally characterize the difference between the training stimuli. This suggests a transition from generalization based on simple physical similarity to generalization based on a “verbalizable” rule, as a consequence of additional relevant information becoming available during test. An explanation appealing to both associative and strategically controlled verbal processes provides an accurate account of the results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)