Tracking Thermo-Oxidation Reaction Products and Pathways of Modified Lignin Structures from Reactive Molecular Dynamics Simulations.

Thermo-oxidation of biomass is an important process that occurs through a variety of reaction pathways depending on the chemical nature of the molecules and reaction conditions. These processes can be modeled using reactive molecular dynamics to study chemical reactions and the evolution of converted molecules over time. The advantage of this approach is that many molecules can be modeled, but it is challenging to use the large amount of data obtained from such a simulation to determine reaction products and pathways. In this study, we developed a tracking approach to identify the reaction pathways of the dominant reaction products from reactive molecular dynamics simulations. We demonstrated the approach for thermo-oxidation reactions of modified model lignin compounds. For two modified lignin structures, we tracked the evolving chemical species to find the most common reaction products. Subsequently, we monitored specific bonds to determine the individual steps in the reaction process. This combined approach of reactive molecular dynamics and tracking enabled us to identify the most likely thermo-oxidation pathways. The methodology can be used to investigate the thermo-oxidative pathways of a wider range of chemical compounds.

Increased expression of receptor phosphotyrosine phosphatase-ß/ζ is associated with molecular, cellular, behavioral and cognitive schizophrenia phenotypes.

Schizophrenia is a serious and chronic mental disorder, in which both genetic and environmental factors have a role in the development of the disease. Neuregulin-1 (NRG1) is one of the most established genetic risk factors for schizophrenia, and disruption of NRG1 signaling has been reported in this disorder. We reported previously that NRG1/ErbB4 signaling is inhibited by receptor phosphotyrosine phosphatase-ß/ζ (RPTP ß/ζ) and that the gene encoding RPTPß/ζ (PTPRZ1) is genetically associated with schizophrenia. In this study, we examined the expression of RPTPß/ζ in the brains of patients with schizophrenia and observed increased expression of this gene. We developed mice overexpressing RPTPß/ζ (PTPRZ1-transgenic mice), which showed reduced NRG1 signaling, and molecular and cellular changes implicated in the pathogenesis of schizophrenia, including altered glutamatergic, GABAergic and dopaminergic activity, as well as delayed oligodendrocyte development. Behavioral analyses also demonstrated schizophrenia-like changes in the PTPRZ1-transgenic mice, including reduced sensory motor gating, hyperactivity and working memory deficits. Our results indicate that enhanced RPTPß/ζ signaling can contribute to schizophrenia phenotypes, and support both construct and face validity for PTPRZ1-transgenic mice as a model for multiple schizophrenia phenotypes. Furthermore, our results implicate RPTPß/ζ as a therapeutic target in schizophrenia.

Animals lacking endothelin-converting enzyme-2 are deficient in learning and memory.

Endothelin-converting enzyme (ECE)-2 is a metalloprotease that possesses many properties consistent with it being a neuropeptide-processing enzyme. This protease is found primarily in neural tissues, with high levels of expression in midbrain, cerebellum, hypothalamus, frontal cortex and spinal cord and moderate levels in hippocampus and striatum. To evaluate its role in neural function, mice have been generated lacking this enzyme. Physical appearance, autonomic reflexes, motor co-ordination, balance, locomotor activity and spontaneous emotional responses appear normal in these knockout (KO) mice. However, these mutants display deficits in learning and memory as evidenced by marked impairment in the Morris water maze. Knockout mice are also deficient in object recognition memory where they show delays in discerning changes in object location and in recognizing the introduction of a novel object. In this study, perseveration appears to interfere with learning and memory. Finally, mutants are impaired in social transmission of food preference where they show poor short-term memory and perturbations in long-term memory; the latter can be ameliorated by reminder cues. As ECE-2 has been implicated in Alzheimer's disease, the deficits in learning and memory in the KO mice may provide unique insights into processes that may contribute to this disease and possible other disorders of cognition.

Status differences and in-group bias: a meta-analytic examination of the effects of status stability, status legitimacy, and group permeability.

This work examines the moderating effects of status stability, legitimacy, and group permeability on in-group bias among high- and low-status groups. These effects were examined separately for evaluative measures that were relevant as well as irrelevant to the salient status distinctions. The results support social identity theory and show that high-status groups are more biased. The meta-analysis reveals that perceived status stability, legitimacy, and permeability moderate the effects of group status. Also, these variables interacted in their influences on the effect of group status on in-group bias, but this was only true for irrelevant evaluative dimensions. When status was unstable and perceived as illegitimate, low-status groups and high-status groups were equally biased when group boundaries were impermeable, compared with when they were permeable. Implications for social identity theory as well as for intergroup attitudes are discussed.

A meta-analysis of fibromyalgia treatment interventions.

OBJECTIVE: To evaluate and compare the efficacy of pharmacological and nonpharmacological treatments of fibromyalgia syndrome (FMS). METHODS: This meta-analysis of 49 fibromyalgia treatment outcome studies assessed the efficacy of pharmacological and nonpharmacological treatment across four types of outcome measures-physical status, self-report of FMS symptoms, psychological status, and daily functioning. RESULTS: After controlling for study design, antidepressants resulted in improvements on physical status and self-report of FMS symptoms. All nonpharmacological treatments were associated with significant improvements in all four categories of outcome measures with the exception that physically-based treatment (primarily exercise) did not significantly improve daily functioning. When compared, nonpharmacological treatment appears to be more efficacious in improving self-report of FMS symptoms than pharmacological treatment alone. A similar trend was suggested for functional measures. CONCLUSION: The optimal intervention for FMS would include nonpharmacological treatments, specifically exercise and cognitive-behavioral therapy, in addition to appropriate medication management as needed for sleep and pain symptoms.

Psychosocial correlates of voluntary HIV antibody testing in college students.

Although past research has examined correlates of HIV testing, much of it has focused on demographic differences between tested and nontested individuals. The present study examined psychosocial differences between individuals seeking a voluntary HIV test at a college student health center and individuals who have never had an HIV test. Variables included in the model were four components of the health belief model (perceived susceptibility, perceived severity, perceived benefits, perceived barriers), as well as perceived norms, consideration of future consequences, and risky sexual behavior. Results suggest that individuals seeking an HIV test perceived more benefits of having a test, tended to perceive fewer barriers to having a test, were higher in consideration of Future Consequences, and engaged in riskier sexual behavior than individuals never having had an HIV test. Implications for both HIV testing interventions and the health belief model are discussed.

Relationship between individual-cow udder health status in early lactation and dairy cow characteristics in Brittany, France.

Data from a 4-year ecopathological survey involving 47 dairy farms in Brittany (France) were used to determine the individual animal characteristics associated with the udder health profiles of clinical and subclinical mastitis, and the presence of minor or major pathogens in milk during early lactation. Herd effect was taken into account and a within-herd analysis using factorial correspondence analysis and a decomposition of chi-square distance was performed. In primiparous cows, the main association observed was between milk production and intramammary infections with major pathogens. The dirtiness score showed contradictory relationships with udder health profiles. The indoor/outdoor transition period was unfavourable for udder health status; since the frequency rate of subclinical and clinical mastitis increased during this period. In multiparous cows, intramammary infections by minor or major pathogens were closely associated with non-infectious udder diseases, but the main effect was due to parity. Old cows were generally affected by higher somatic cell counts than younger cows regardless of whether the SCC were associated with clinical mastitis or not.

Interrelationships between herd management practices and udder health status using canonical correspondence analysis.

The relationships between the herd-level distribution of udder health measures (traumatic, physical, functional and congestive udder disorders, clinical mastitis and somatic cell counts (SCC) greater than 400 x 10(3) ml-1) and farm (general hygiene, milking practices and housing system) and aggregated individual characteristics were studied by canonical correspondence analysis (CCA). This is a correspondence-analysis technique in which the axes representing disease patterns are expressed as linear combinations of potentially explanatory variables. These main axes can be drawn so that the distribution of diseases for combinations of the main-explanatory managerial variables can be visualized. The type of quarantine for newcomers, type of animal housing, presence of shelter at pasture, use of udder towel before milking, milk production and loss of body condition after calving, were strongly correlated with udder health status. Mastitis and physical udder disorders were associated with the combination of no introduction of replacement heifers and low loss of body condition after calving. Congestive disorders were more common on farms when no quarantine for newcomers was combined with high loss of body condition after calving. Higher clinical and subclinical mastitis incidence risks were associated with the combination of no udder towel, loose housing with high animal density and high milk production. In most cases, clinical mastitis and high SCC were explained by the same covariates but with contrasting levels of those covariates.

Farming practices associated with the 'udder infection' complex.

A total of 4,129 dairy cows from 47 dairy farms were submitted each year after calving to a milk sampling for bacteriological examination. Six criteria defined the udder infection complex: frequency of minor, major and rare pathogens; rate of clinical and subclinical mastitis; and index of gravity of mastitis. Forty-seven variables described practices and their associations with the type of farms (defined by the above 6 criteria) were studied. The associated variables were dipping practices, covering of the milking parlour, disinfection practices, housing cleanliness and milk production.