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

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

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

Hypoxia-enhanced Blood-Brain Barrier Chip recapitulates human barrier function and shuttling of drugs and antibodies

The high selectivity of the human blood-brain barrier (BBB) restricts delivery of many pharmaceuticals and therapeutic antibodies to the central nervous system. Here, we describe an in vitro microfluidic organ-on-a-chip BBB model lined by induced pluripotent stem cell-derived human brain microvascular endothelium interfaced with primary human brain astrocytes and pericytes that recapitulates the high level of barrier function of the in vivo human BBB for at least one week in culture. The endothelium expresses high levels of tight junction proteins and functional efflux pumps, and it displays selective transcytosis of peptides and antibodies previously observed in vivo. Increased barrier functionality was accomplished using a developmentally-inspired induction protocol that includes a period of differentiation under hypoxic conditions. This enhanced BBB Chip may therefore represent a new in vitro tool for development and validation of delivery systems that transport drugs and therapeutic antibodies across the human BBB

Matrilineal behavioral and physiological changes following the death of a non-alpha matriarch in rhesus macaque

In many species, the loss of alpha matriarchs is associated with a number of negative outcomes such as troop fission, eviction, wounding, and reduced vitality. However, whether the dramatic consequences of their loss are due to their role as an old experienced figure or to their alpha status remains unclear. In a retrospective study, we tested that in a semi-free ranging colony of rhesus macaques (Macaca mulatta), the removal of a non-alpha matriarch, who had a large set of kin, led to changes in behavior and physiological stress within her matriline. Following her removal, her matriline increased in aggression, vigilance, and social grooming. Additionally, hierarchical stability, measured by levels of rank changes, decreased within her matriline, and levels of intense aggression by high-ranking animals were more frequent, as well as matrilineal wounding. Although ordinal rank was positively associated with higher chronic hair cortisol concentrations (HCCs) in the months before the matriarch’s removal, following her removal, only those who experienced large increases in rank within her matriline displayed higher HCCs. Changes in matrilineal stability, aggression, behavior, and HCCs within the other two matrilines in the troop were not evident, although caution is needed due to the small sample sizes. We conclude that the removal of the non-alpha matriarch led to matrilineal instability, characterized by higher levels of aggression and subsequent vigilance, rank changes, physiological stress, and grooming. We suggest that non-alpha matriarchs with a large number of kin and social support can be integral to the stability of matrilines.Division of Intramural Research, National Institute of Child Health and Human Development, 1ZIAHD001107- 3

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

?-glycosidase of the GH3 family produced by filamentous fungus isolated from the intestine of Nausitora fusticula (Bivalvia: Teredinidae) / ?-glicosidase da família GH3 produzida por fungo filamentoso isolado do intestino de Nausitora fusticula (Bivalvia: Teredinidae)

Cellulolytic enzymes are those that are able to break down cellulose into its monomeric component, glucose. This group of enzymes is divided into endoglucanases that act inside the cellulosic fiber, exoglucanases that act on the ends of the chains, and ?-glucosidases that act on endo and exoglucanase products, cellobiose, releasing glucose as the final product. The main producers of these enzymes are filamentous fungi and the search for new microbial sources of these enzymes is essential for research involving the production of bioethanol, to improve the efficiency of this process. The objective of this work was to investigate the production of the cellulolytic complex in a lineage of filamentous fungus, isolated from the intestine of specimens of the teredo species Nausitora fusticula, to characterize some biochemical properties of the isolated enzymes and partially purify them to obtain a cellulolytic extract. From the digestive system of N. fusticula, were isolated fungi good producers of cellulases, which were classified as better producers through enzyme index tests. One specie stood out in the production of the three investigated enzymes, and this was grown in a medium containing carboxymethylcellulose and sugarcane bagasse as substrates for obtaining enzymatic extracts. Cultures with sugarcane bagasse produced a greater amount of cellulases. The production kinetics of these enzymes was evaluated in cultures of up to six days. The temperature and optimum pH of each enzyme was verified, as well as their stability at a temperature of 52º C. The enzymes were partially purified by the ion exchange technique and analyzed by mass spectrometry. The enzyme ?-glycosidase produced showed high similarity with ?-glycosidases of the GH3 family produced by the fungal species Bipolaris sorokiniana. The morphological characteristics of the isolated strain of N. fusticula intestine were very similar to those described for the species B. sorokiniana, which strongly suggests the correlation of these species and consequently the enzymes produced by them

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