How does target duration affect object substitution masking?

Object substitution masking (OSM) is typically studied using a brief search display. The target item may be indicated by a cue/mask surrounding but not overlapping it. Report of the target is reduced when mask offset trails target offset rather than being simultaneous with it. We report 5 experiments investigating whether OSM can be obtained if the search display is on view for a period of up to 830 ms but cueing of the target location is delayed. The question of interest is whether OSM must reflect the initial response of the visual system to target onset or whether it can arise in other ways, possibly during the transition from a pre-attentive representation of the target item to an attentional representation of it. Our results show that OSM decreases in strength as target duration increases. An explanation is suggested in terms of the object individuation hypothesis (Lleras & Moore, 2003). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Molecular Mechanisms of Skewed X-Chromosome Inactivation in Female Hemophilia Patients—Lessons from Wide Genome Analyses

Introduction: Hemophilia A (HA) is an X-linked bleeding disorder caused by factor VIII (FVIII) deficiency or dysfunction due to F8 gene mutations. HA carriers are usually asymptomatic because their FVIII levels correspond to approximately half of the concentration found in healthy individuals. However, in rare cases, a carrier may exhibit symptoms of moderate to severe HA primarily due to skewed inactivation of her non-hemophilic X chromosome. Aim: The aim of the study was to investigate X-chromosome inactivation (XCI) patterns in HA carriers, with special emphasis on three karyotypically normal HA carriers presenting with moderate to severe HA phenotype due to skewed XCI, in an attempt to elucidate the molecular mechanism underlying skewed XCI in these symptomatic HA carriers. The study was based on the hypothesis that the presence of a pathogenic mutation on the non-hemophilic X chromosome is the cause of extreme inactivation of that X chromosome. Methods: XCI patterns were studied by PCR analysis of the CAG repeat region in the HUMARA gene. HA carriers that demonstrated skewed XCI were further studied by whole-exome sequencing (WES) followed by X chromosome-targeted bioinformatic analysis. Results: All three HA carriers presenting with the moderate to severe HA phenotype due to skewed XCI were found to carry pathogenic mutations on their non-hemophilic X chromosomes. Patient 1 was diagnosed with a frameshift mutation in the PGK1 gene that was associated with familial XCI skewing in three generations. Patient 2 was diagnosed with a missense mutation in the SYTL4 gene that was associated with familial XCI skewing in two generations. Patient 3 was diagnosed with a nonsense mutation in the NKAP gene that was associated with familial XCI skewing in two generations. Conclusion: Our results indicate that the main reason for skewed XCI in our female HA patients was negative selection against cells with a disadvantage caused by an additional deleterious mutation on the silenced X chromosome, thus complicating the phenotype of a monogenic X-linked disease. Based on our study, we are currently offering the X inactivation test to symptomatic hemophilia carriers and plan to expand this approach to symptomatic carriers of other X-linked diseases, which can be further used in pregnancy planning.     

Temperature dependence and interferences of NO and N₂O microelectrodes used in wastewater treatment

Electrodes for nitric and nitrous oxide have been on the market for some time, but have not yet been tested for an application in wastewater treatment processes. Both sensors were therefore assessed with respect to their (non)linear response, temperature dependence and potential cross sensitivity to dissolved compounds, which are present and highly dynamic in nitrogen conversion processes (nitric oxide, nitrous oxide, nitrogen dioxide, ammonia, hydrazine, hydroxylamine, nitrous acid, oxygen, and carbon dioxide). Off-gas measurements were employed to differentiate between cross sensitivity to interfering components and chemical nitric oxide or nitrous oxide production. Significant cross sensitivities were detected for both sensors: by the nitrous oxide sensor to nitric oxide and by the nitric oxide sensor to ammonia, hydrazine, hydroxylamine and nitrous acid. These interferences could, however, be removed by correction functions. Temperature fluctuations in the range of ±1 °C lead to artifacts of ±3.5% for the nitric oxide and ±3.9% for the nitrous oxide sensor and can be corrected with exponential equations. The results from this study help to significantly shorten and optimize the determination of the correction functions and are therefore relevant for all users of nitric and nitrous oxide electrodes.     

High Dose trans-10,cis-12 CLA Increases Lean Body Mass in Hamsters, but Elevates Levels of Plasma Lipids and Liver Enzyme Biomarkers

The current study examined the efficacy of graded doses of c9,t11 and t10,c12 CLA isomers on body composition, energy expenditure, hepatic and serum lipid liver biomarkers in hamsters. Animals (n = 105) were randomized to seven treatments (control, 1, 2, 3% of c9,t11; 1, 2, 3% of t10,c12) for 28 days. After 28 days treatment, 1–3% of t10,c12 lowered (p < 0.05) body fat mass compared to the control group. The 1–3% t10,c12 and 3% c9,t11 fed groups showed higher (p < 0.05) lean mass compared to other groups. We observed unfavorable changes in plasma total cholesterol and non-HDL cholesterol levels in animals fed with 3% t10,c12 CLA isomers. The 2%, 3% t10,c12 groups presented elevated (p < 0.05) ALT levels. The present data suggest that a diet enriched with more than 2% t10, c12 led to liver malfunction and poses unfavorable changes on plasma lipid profiles. The 1% t10,c12 CLA lowered (p < 0.05) body fat mass and increased (p < 0.05) lean body mass. The c9,t11 CLA has less potent actions than t10,c12 CLA. We conclude that the actions of CLA on energy and lipid metabolism are form and dose dependent in the hamster model.     

紫苏咀嚼片制备工艺的研究

目的 研究紫苏咀嚼片的制备工艺,开发紫苏营养保健品.方法 通过对紫苏粉、甜味剂、酸味剂、紫苏香精、润滑剂、填充剂的考察,确定合理的原辅料配比;采用湿法制粒压片法,经原辅料混合、制软材、制粒、干燥、压片、包衣等工序,制备紫苏咀嚼片.结果 紫苏咀嚼片配方合理、工艺简单可行,产品表面光滑、口味较好.结论 湿法制粒压片法适于制备本品.     

Laboratory evaluation of traps for the detection of beetle pests in bulk grain

Traps have been evaluated against three species of storage beetle in plastic bins containing 150 kg wheat. The bins were used to generate data for a comparison of the trapping effectiveness of the pitfall cone (PC), pitfall beaker and insect probe traps. The data produced reflect those obtained from field studies and illustrate the advantages of this method over less rigorously controlled field trials. The PC trap, a single type developed to replace both of the previously recommended traps, buried to a 5 cm depth in grain, was as effective as the insect probe for detecting Cryptolestes ferrugineus. The buried PC trap was also as effective as the insect probe trap for trapping Oryzaephilus surinamensis below the grain surface, and the PC trap on the surface was as effective as the pitfall beaker trap. The PC trap below the surface was more effective for trapping Sitophilus granarius than the insect probe trap. This pilot-scale method is a cost-effective alternative to field-scale trials and could be used to investigate various factors influencing trap catch.     

A population approach to initial dose selection

Before a drug can be marketed, an initial dose must be established. Sheiner et al. argue that a population approach leads to the most informed and rational decision making. We discuss the choice of an initial dose from both a predictive and estimative viewpoint. Our criteria are based upon evaluating the probabilities that a patient from the specified population obtains a response that is at least of a specified size. We demonstrate the approach using a simulation study and compare estimation of population parameters and initial dose using Bayesian and likelihood-based methods.     

Oxidative stability of jojoba wax

The rates of autoxidation of crude, bleached and stripped jojoba wax were determined under conditions of accelerated oxidation (98 C). Oxidation of the raw yellow wax had a long induction period (50 hr) compared with the bleached wax (10–12 hr) or stripped wax (2 hr). These differences indicate the presence of a natural antioxidant in the crude wax. Addition of 0.02% butylated hydroxytoluene or butylated hydroxyanisole to the bleached wax restored and even improved its stability. Autoxidation of jojoba wax was also studied at room temperature. In the presence of light and air, the activity of the natural inhibitor was rapidly lost.     

Histone underacetylation is an ancient component of mammalian X chromosome inactivation

Underacetylation of histone H4 is thought to be involved in the molecular mechanism of mammalian X chromosome inactivation, which is an important model system for large-scale genetic control in eukaryotes. However, it has not been established whether histone underacetylation plays a critical role in the multistep inactivation pathway. Here we demonstrate differential histone H4 acetylation between the X chromosomes of a female marsupial, Macropus eugenii. Histone underacetylation is the only molecular aspect of X inactivation known to be shared by marsupial and eutherian mammals. Its strong evolutionary conservation implies that, unlike DNA methylation, histone underacetylation was a feature of dosage compensation in a common mammalian ancestor, and is therefore likely to play a central role in X chromosome inactivation in all mammals.     

Asthma prevalence, morbidity and management practices in South Australia, 1992-1995

BACKGROUND: The Spring South Australian Health Omnibus Survey (SSAHOS) has been used to monitor trends in asthma prevalence, asthma morbidity and asthma management practices between 1992 and 1995. AIMS: To determine if self-reported asthma prevalence and availability of asthma action plans were increasing. To identify deficiencies in asthma management and opportunities for intervention. METHODS: Representative population survey by trained interviewers using a multistage, systematic, clustered area sample of 4200 households in South Australia where people aged 15 years or more are living. RESULTS: Over 3000 interviews were conducted each year. Between 1992 and 1995 the self-reported prevalence of asthma in those aged 15 years or more increased significantly from 15.7% to 20.3% (p < 0.0005), and the prevalence of current asthma increased from 9.3% to 11.4% (p < 0.05). The self-reported availability of individual asthma action plans increased from 21.9% in 1992 to 42.2% in 1995 (p < 0.0005). In 1992, 21% had a nebuliser at home, and 10.5% had a peak flow meter. In 1993, 61.4% were using preventive medications, and 35% thought bronchodilators were 'preventer' medications. In 1994 and 1995, between 12.5% and 15.6% had nocturnal awakening weekly or more often, and 31.4% had morning asthma symptoms weekly or more often. Between 20.1% and 20.8% had lost days from usual activities during the last year. Those on incomes below $20,000 had more symptoms, had more admissions to hospital, and required more medication than those on higher incomes. CONCLUSIONS: Self-reported asthma prevalence has increased. There remains a gap between current asthma management and that recommended by the National Asthma Campaign.