Drought and oxidative stress

Drought, a natural stress factor has the highest percentage with 26%, when the usable areas on the earth are classified in view of stress factors. Biotic and abiotic stress factors may cause yield loss in plants and affect human and animal nutrition. Amount of lacking yield due to biotic and abiotic stress factors ranged between 65 and 87%. The best option for crop production, yield improvement and yield stability under soil moisture deficient conditions is to develop drought tolerant crop varieties (Siddique et al., 2000). A physiological approach would be the most attractive way to develop new varieties rapidly. Only few studies highlighted the importance of antioxidant enzymes during drought stress. The antioxidant defenses appear to provide crucial protection against oxidative damage in cellular membranes and organelles in plants grown under unfavorable conditions. Thus, plants are equipped with complex and a highly efficient antioxidative defense system which can respond and adapt to drought stress. This system is composed of protective nonenzymatic and enzymatic protection mechanisms. They interrupt the uncontrolled oxidation and serve to maintain the antioxidants in their reduced functional state, that efficiently scavenge ROS (reactive oxygen species) and prevent damaging effects of free radicals. Balance at aerobic metabolism is defined as free radical generation and rapid removal by antioxidant systems. The structure of cells and functional changes of systems, may be damaged by the formation of irreversible oxidative stress. Redox signalling and antioxidative defense systems are very important for protection towards uncontrolled and cascade damage of biotic and abiotic stress factors. In this review, drought, drought types and antioxidative defense system components will be discussed.Key words: Antioxidative defense system, ascorbate peroxidase, catalase, drought types, glutathione reductase, oxidative stress, superoxide dismutase

Statistical Shape Modeling to Quantify Variation in the Proximal Humeral Anatomy

The fit of the humeral prosthesis to the intramedullary canal and the replication of the anatomic humeral head center are important factors in Total Shoulder Arthroplasty (TSA). The objective of this thesis was to develop a Statistical Shape Model (SSM) of the cortical and cancellous bone regions of the proximal humerus, and to assess potential shape differences with gender and ethnicity, with a goal of informing implant design. An SSM was used and Principal Component Analysis (PCA) was applied to data that represented both the cancellous and cortical humeral bone of 63 healthy subjects and cadavers. Anatomical measurements and PC scores were analyzed by gender and ethnicity. Scaling accounted for 75% of the variation in the training set. Differences between males and females were primarily in size. Ethnicity differences were observed in the relationship between medial and posterior offset. Differences in ethnicity and/or gender were observed in the relationship between posterior offset and the head inclination angle. These are differences that should be considered when designing implants for a global population or subpopulation

Localization transition on complex networks via spectral statistics

The spectral statistics of complex networks are numerically studied. The features of the Anderson metal-insulator transition are found to be similar for a wide range of different networks. A metal-insulator transition as a function of the disorder can be observed for different classes of complex networks for which the average connectivity is small. The critical index of the transition corresponds to the mean field expectation. When the connectivity is higher, the amount of disorder needed to reach a certain degree of localization is proportional to the average connectivity, though a precise transition cannot be identified. The absence of a clear transition at high connectivity is probably due to the very compact structure of the highly connected networks, resulting in a small diameter even for a large number of sites.Comment: 6 pages, expanded introduction and referencess (to appear in PRE

Expression and localization of claudins-3 and -12 in transformed human brain endothelium

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to characterize the hCMEC/D3 cell line, an <it>in vitro </it>model of the human Blood Brain Barrier (BBB) for the expression of brain endothelial specific claudins-3 and -12.</p> <p>Findings</p> <p>hCMEC/D3 cells express claudins-3 and -12. Claudin-3 is distinctly localized to the TJ whereas claudin -12 is observed in the perinuclear region and completely absent from TJs. We show that the expression of both proteins is lost in cell passage numbers where the BBB properties are no longer fully conserved. Expression and localization of claudin-3 is not modulated by simvastatin shown to improve barrier function <it>in vitro </it>and also recommended for routine hCMEC/D3 culture.</p> <p>Conclusions</p> <p>These results support conservation of claudin-3 and -12 expression in the hCMEC/D3 cell line and make claudin-3 a potential marker for BBB characteristics <it>in vitro</it>.</p

Relationship of vascular variations with liver remnant volume in living liver transplant donors

Background: In this study, we investigated the relationship between the portal vein and hepatic artery variations and the remaining liver volume in living donors in liver transplantation.Materials and methods: In the study, triphasic abdominal computed tomography images of 180 live liver donor candidates were analysed retrospectively. Portal veins were divided into four groups according to the Nakamura classification and seven groups according to the Michels classification. The relationship between vascular variations and remnant liver volume was compared statistically.Results: According to the Nakamura classification, there were 143 (79.4%) type A, 23 (12.7%) type B, 7 (3.9%) type C and 7 (3.9%) type D cases. Using the Michels classification, 129 (71%) type 1, 12 (6.7%) type 2, 24 (13%) type 3, 2 (2.2%) type 4, 10 (5.6%) type 5, 1 (0.6%) type 6, and 2 (1.1%) type 7 cases were detected. There was no significant difference in the percentage of the remaining volume of the left liver lobe between the groups (p = 0.055, p = 0.207, respectively).Conclusions: Variations in the hepatic artery and portal vein do not affect the remaining liver volume in liver transplantation donors

Facial stereotypes and perceived mental illness

It is well established that we carry stereotypes that impact on human perception and behaviour (e.g. G.W. Allport, “The nature of prejudice”. Reading, MA: Addison-Wesley, 1954). Here, we investigate the possibility that we hold a stereotype for a face indicating that its owner may have a mental illness. A three-stage face-perception experiment suggested the presence of such a stereotype. Participants first rated 200 synthetic male faces from the EvoFIT facial-composite system for perceived mental illness (PMI). These faces were used to create a computer-based rating scale that was used by a second sample of participants to make a set of faces appear mentally ill. There was evidence to suggest that the faces that participants identified using the PMI scale differed along this dimension (although not entirely as expected). In the final stage of the study, another set of synthetic faces were created by artificially increasing and decreasing levels along the scale. Participants were asked to rate these items for PMI and for six criminal types. It was found that participants assigned higher PMI ratings (cf. veridical) for items with inflated PMI (although there was no reliable difference in ratings between veridical faces and faces with decreased PMI). Implications of the findings are discussed

Predicting fine-scale daily NO2 over Mexico city using an ensemble modeling approach

In recent years, there has been growing interest in developing air pollution prediction models to reduce exposure measurement error in epidemiologic studies. However, efforts for localized, fine-scale prediction models have been predominantly focused in the United States and Europe. Furthermore, the availability of new satellite instruments such as the TROPOsopheric Monitoring Instrument (TROPOMI) provides novel opportunities for modeling efforts. We estimated daily ground-level nitrogen dioxide (NO2) concentrations in the Mexico City Metropolitan Area at 1-km2 grids from 2005 to 2019 using a four-stage approach. In stage 1 (imputation stage), we imputed missing satellite NO2 column measurements from the Ozone Monitoring Instrument (OMI) and TROPOMI using the random forest (RF) approach. In stage 2 (calibration stage), we calibrated the association of column NO2 to ground-level NO2 using ground monitors and meteorological features using RF and extreme gradient boosting (XGBoost) models. In stage 3 (prediction stage), we predicted the stage 2 model over each 1-km2 grid in our study area, then ensembled the results using a generalized additive model (GAM). In stage 4 (residual stage), we used XGBoost to model the local component at the 200-m2 scale. The cross-validated R2 of the RF and XGBoost models in stage 2 were 0.75 and 0.86 respectively, and 0.87 for the ensembled GAM. Cross-validated root-mean-squared error (RMSE) of the GAM was 3.95 μg/m3. Using novel approaches and newly available remote sensing data, our multi-stage model presented high cross-validated fits and reconstructs fine-scale NO2 estimates for further epidemiologic studies in Mexico City

Canal wall reconstruction and mastoid obliteration with composite multi-fractured osteoperiosteal flap

We used inferior pedicled composite multi-fractured osteoperiosteal flap (CMOF), our original and new surgical approach, to obliterate the mastoid cavity and reconstruct the external auditory canal (EAC) to prevent the open cavity problems. CMOF was used to obliterate the mastoid cavity and reconstruct the EAC in 24 patients (13 women, 11 men; age span 12–51 years) who underwent radical mastoidectomy to treat the chronic otitis media between 1998 and 2004. Small meatoplasty was done in all 24 patients to relive their aesthetical concerns. Temporal bone CT scanning was done to observe the neo-osteogenesis in the mastoidectomy cavity and the CMOF, and the EAC volume was measured postoperatively. All our patients were followed-up for 2 years. The epithelization of the new EAC in our patients was complete at the end of the second month. Cholesteatoma, granulation, and recurrence of osteitis did not occur in any of the patients. We saw the new bone formation filling the mastoid cavity in the postoperative temporal bone CT scanning images. The mean volume of the new EAC on the 24th month was 1.83 ± 0.56 cm(3). We had an almost natural EAC, which owed its existence to the neo-osteogenesis that grows behind the CMOF, which we use to obliterate the mastoid cavity and to reconstruct the EAC

EACVI survey on radiation exposure in interventional echocardiography.

AIMS: The European Association of Cardiovascular Imaging (EACVI) Scientific Initiatives Committee performed a global survey on radiation exposure in interventional echocardiography. The survey aimed to collect data on local practices for radioprotection in interventional echocardiography and to assess the awareness of echocardiography operators about radiation-related risks. METHODS AND RESULTS: A total of 258 interventional echocardiographers from 52 different countries (48% European) responded to the survey. One hundred twenty-two (47%) participants were women. Two-thirds (76%) of interventional echocardiographers worked in tertiary care/university hospitals. Interventional echocardiography was the main clinical activity for 34% of the survey participants. The median time spent in the cath-lab for the echocardiographic monitoring of structural heart procedures was 10 (5-20) hours/month. Despite this, only 28% of interventional echocardiographers received periodic training and certification in radioprotection and 72% of them did not know their annual radiation dose. The main adopted personal protection devices were lead aprons and thyroid collars (95% and 92% of use, respectively). Dedicated architectural protective shielding was not available for 33% of interventional echocardiographers. Nearly two-thirds of responders thought that the radiation exposure of interventional echocardiographers was higher than that of interventional cardiologists and 72% claimed for an improvement in the radioprotection measures. CONCLUSION: Radioprotection measures for interventional echocardiographers are widely variable across centres. Radioprotection devices are often underused by interventional echocardiographers, portending an increased radiation-related risk. International scientific societies working in the field should collaborate to endorse radioprotection training, promote reliable radiation dose assessment, and support the adoption of radioprotection shielding dedicated to interventional echocardiographers