Stomatal responses of Eucalyptus species to elevated CO2 concentration and drought stress

Five species of Eucalyptus (E. grandis, E. urophylla, E. camaldulensis, E. torelliana, and E. phaeotrica), among the ten species most commonly used in large scale plantations, were selected for studies on the effects of elevated CO2 concentration [CO2] and drought stress on stomatal responses of 2.5-month old seedlings. The first three species belong to the subgenus Smphyomyrtus, whereas the fourth species belongs to the subgenus Corymbia and E. phaeotrica is from the subgenus Monocalyptus. Seedlings were grown in four pairs of open-top chambers, arranged to have 2 plants of each species in each chamber, with four replications in each of two CO2 concentrations: 350 ± 30 mumol mol-1 and 700 ± 30 mumol mol-1. After 100 days in the chambers, a series of gas exchange measurements were made. Half the plants in each chamber, one plant per species per chamber, were drought-stressed by withholding irrigation, while the remaining plants continued to be watered daily. Drought stress decreased stomatal conductance, photosynthesis and transpiration rates in all the species. The effect of drought stress on stomatal closure was similar in both [CO2]. The positive effects of elevated [CO2] on photosynthesis and water use efficiency were maintained longer during the stress period than under well-watered conditions. The photosynthetic rate of E. phaeotrica was higher even in the fourth day of the drought stress. Drought stress increased photoinhibition of photosynthesis, as measured by chlorophyll fluorescence, which varied among the species, as well as in relation to [CO2]. The results are in agreement with observed differences in stomatal responses between some eucalyptus species of the subgenera Symphyomyrtus and Monocalyptus

Post-acute COVID-19 neuropsychiatric symptoms are not associated with ongoing nervous system injury

A proportion of patients infected with severe acute respiratory syndrome coronavirus 2 experience a range of neuropsychiatric symptoms months after infection, including cognitive deficits, depression and anxiety. The mechanisms underpinning such symptoms remain elusive. Recent research has demonstrated that nervous system injury can occur during COVID-19. Whether ongoing neural injury in the months after COVID-19 accounts for the ongoing or emergent neuropsychiatric symptoms is unclear. Within a large prospective cohort study of adult survivors who were hospitalized for severe acute respiratory syndrome coronavirus 2 infection, we analysed plasma markers of nervous system injury and astrocytic activation, measured 6 months post-infection: neurofilament light, glial fibrillary acidic protein and total tau protein. We assessed whether these markers were associated with the severity of the acute COVID-19 illness and with post-acute neuropsychiatric symptoms (as measured by the Patient Health Questionnaire for depression, the General Anxiety Disorder assessment for anxiety, the Montreal Cognitive Assessment for objective cognitive deficit and the cognitive items of the Patient Symptom Questionnaire for subjective cognitive deficit) at 6 months and 1 year post-hospital discharge from COVID-19. No robust associations were found between markers of nervous system injury and severity of acute COVID-19 (except for an association of small effect size between duration of admission and neurofilament light) nor with post-acute neuropsychiatric symptoms. These results suggest that ongoing neuropsychiatric symptoms are not due to ongoing neural injury

Cultural identity and peer influence as predictors of substance use among culturally diverse Australian adolescents

This study investigated cultural identity and peer influence on tobacco, alcohol, and cannabis use in a culturally diverse sample of Northern Australian adolescents. Middle school students (n = 274) completed the Multigroup Ethnic Identity Measure (MEIM) and measures of their own and perceived friends' substance use. Higher scores on the full scale MEIM indicating stronger cultural identity were found to be independently protective of Indigenous and Non-Indigenous alcohol initiation. More friends using substances was associated with increased substance use risk for both cultural groups. A factor analysis of the MEIM identified a two-factor structure, consisting of Affirmation/Belonging and Participation/Exploration. Few significant associations were found between the MEIM factors and cultural group substance use. Interactions between the MEIM factors and friends' substance use indicated the two factors acted in the same way and decreased Non-Indigenous alcohol initiation for up to four drinking friends but were associated with risk for Indigenous alcohol initiation with any number of drinking friends. Copyright © 2011 by SAGE Publication

Can Asset Pricing Models Price Idiosyncratic Risk in U.K. Stock Returns?

I examine how well different linear factor models and consumption-based asset pricing models price idiosyncratic risk in U.K. stock returns. Correctly pricing idiosyncratic risk is a significant challenge for many of the models I consider. For some consumption-based models, there is a clear tradeoff in the performance of the models between correctly pricing systematic risk and idiosyncratic risk. Linear factor models do a better job in most cases in pricing systematic risk than consumption-based models but the reverse is true for idiosyncratic risk. Copyright 2007, The Eastern Finance Association.

Up-regulation of mitochondrial antioxidation signals in ovarian cancer cells with aggressive biologic behavior

Objective: Recently, a high frequency of mutations in mitochondrial DNA (mtDNA) has been detected in ovarian cancer. To explore the alterations of proteins in mitochondria in ovarian cancer, a pair of human ovarian carcinoma cell lines (SKOV3/SKOV3.ip1) with different metastatic potentials was examined. Methods: Cancer cells SKOV3.ip1 were derived from the ascitic tumor cells of nude mice bearing a tumor of ovarian cancer cells SKOV3. SKOV3.ip1 exhibited a higher degree of migration potential than its paired cell line SKOV3. The proteins in the mitochondria of these two cells were isolated and separated by 2-D gel electrophoresis. The differently expressed proteins were extracted and identified using matrix assisted laser desorption ionisation/time-of-flight/time-of-flight (MALDI-TOF/TOF), and finally a selected protein candidate was further investigated by immunohistochemistry (IHC) method in nude mice bearing tumor tissues of these two cells. Results: A total of 35 spots with different expressions were identified between the two cells using 2D-polyacrylamide gel electrophoresis (PAGE) approach. Among them, 17 spots were detected only in either SKOV3 or SKOV3.ip1 cells. Eighteen spots expressed different levels, with as much as a three-fold difference between the two cells. Twenty spots were analyzed using MALDI-TOF/TOF, and 11 of them were identified successfully; four were known to be located in mitochondria, including superoxide dismutase 2 (SOD2), fumarate hydratase (FH), mitochondrial ribosomal protein L38 (MRPL38), and mRNA turnover 4 homolog (MRTO4). An increased staining of SOD2 was observed in SKOV3.ip1 over that of SKOV3 in IHC analysis. Conclusions: Our results indicate that the enhanced antioxidation and metabolic potentials of ovarian cancer cells might contribute to their aggressive and metastatic behaviors. The underlying mechanism warrants further study

Variation in 5' Promoter Region of the APOE gene Contributes to Predicting Ischemic Heart Disease (IHD) in the Population at Large: the Copenhagen City Heart Study

The objective of this study was to evaluate whether an increased hazard of developing ischemic heart disease (IHD) is associated with any of the three genotypes A 560 T 832 /A 560 T 832 , A 560 T 832 /A 560 G 832 and A 560 T 832 /T 560 T 832, defined by variations in two non-coding SNPs in the 5′ promoter region of the apolipoprotein E ( APOE) gene. These genotypes were selected because they distinguished between high and low levels of HDL-C, TG and/or T-C in our earlier study of multiple samples defined by gender and population. We found a significant increase (p<0.05) in the hazard of IHD in females with the A 560 T 832 /T 560 T 832 genotype that remained significant after fitting the effects of dyslipidemia, other established risk factors, and the structural isoform variations of the ApoE molecule. We discuss why this statistically significant genetic predictor may not be an appropriate screening test for IHD in the Danish population at large.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65393/1/j.1469-1809.2007.00370.x.pd