Enumerating Cyclic Orientations of a Graph

Acyclic and cyclic orientations of an undirected graph have been widely studied for their importance: an orientation is acyclic if it assigns a direction to each edge so as to obtain a directed acyclic graph (DAG) with the same vertex set; it is cyclic otherwise. As far as we know, only the enumeration of acyclic orientations has been addressed in the literature. In this paper, we pose the problem of efficiently enumerating all the \emph{cyclic} orientations of an undirected connected graph with $n$ vertices and $m$ edges, observing that it cannot be solved using algorithmic techniques previously employed for enumerating acyclic orientations.We show that the problem is of independent interest from both combinatorial and algorithmic points of view, and that each cyclic orientation can be listed with $\tilde{O}(m)$ delay time. Space usage is $O(m)$ with an additional setup cost of $O(n^2)$ time before the enumeration begins, or $O(mn)$ with a setup cost of $\tilde{O}(m)$ time

sectional study

Backgrounds: The aim of this study is identify the main morphological patterns of the pancreas in AIDS patients in use of Higly Active Antiretorviral Therapy (HAART). Methods: We conducted a cross sectional study in the year of 2010. The inclusion criteria were patients older than 18 years who died of AIDS with the use of HAART (2006–2009) and underwent to autopsy. They were compared with a group of 109 patients who died of AIDS in 1995 before the HAART therapy. All the autopsies were made in the Death Verification Service of São Paulo. Results: The HAART group presented pancreas abnormalities lighter than no HAART users. In the HAART group, histology shows: reduction of zymogen granules in the acinar cells (ZG) higher percentage of cases, “dysplasia-like” presents lower and pancreatic acinar atrophy, presents higher percentage of cases compared to no HAART group. The exocrine pancreas in treated patients was distinguished by the high level of atrophy, sharp reduction of zymogen granules and high level of apoptosis, reflecting degeneration and lower level of protein-caloric malnutrition. Conclusions: The islets of Langerhans in HAART group were increased in number and volume and with high level of nuclear dysplasia. The antiviral therapy and a longer survival resulted in a higher atrophy and reduction of enzymes, increasing the apoptosis and generated important changes in the pancreatic islets, probably resulting in clinical laboratory repercussion. We found no evidence of pancreatic histopathological lesions secondary to antiretroviral therapy

PDK1 and HR46 Gene Homologs Tie Social Behavior to Ovary Signals

The genetic basis of division of labor in social insects is a central question in evolutionary and behavioral biology. The honey bee is a model for studying evolutionary behavioral genetics because of its well characterized age-correlated division of labor. After an initial period of within-nest tasks, 2–3 week-old worker bees begin foraging outside the nest. Individuals often specialize by biasing their foraging efforts toward collecting pollen or nectar. Efforts to explain the origins of foraging specialization suggest that division of labor between nectar and pollen foraging specialists is influenced by genes with effects on reproductive physiology. Quantitative trait loci (QTL) mapping of foraging behavior also reveals candidate genes for reproductive traits. Here, we address the linkage of reproductive anatomy to behavior, using backcross QTL analysis, behavioral and anatomical phenotyping, candidate gene expression studies, and backcross confirmation of gene-to-anatomical trait associations. Our data show for the first time that the activity of two positional candidate genes for behavior, PDK1 and HR46, have direct genetic relationships to ovary size, a central reproductive trait that correlates with the nectar and pollen foraging bias of workers. These findings implicate two genes that were not known previously to influence complex social behavior. Also, they outline how selection may have acted on gene networks that affect reproductive resource allocation and behavior to facilitate the evolution of social foraging in honey bees

Quality of life following liver transplantation: a comparative study between Familial Amyloid Neuropathy and liver disease patients

<p>Abstract</p> <p>Background</p> <p>It has been demonstrated in many studies that quality of life can be improved after liver transplantation in patients with liver disease. Nevertherless quality of life improvement in specific groups of transplantated patients such as those with Familial Amyloid Polineuropathy hasn't yet been explored. The present study aimed to compare the change in quality of life following liver transplantation between patients with Familial Amyloid Polineuropathy (FAP) and patients with liver disease.</p> <p>Results</p> <p>Patient's mental quality of life showed an improvement in all liver disease patients, and a worsening in FAP patients, resulting in a significant difference between the two groups. Regarding physical quality of life, although a similar improvement was seen in both groups, FAP patients had significantly less improvement than the sub-group of decompensated liver disease (Child-Pugh B and C).</p> <p>Conclusion</p> <p>It is concluded that liver transplantation has a less beneficial impact in FAP patient's physical quality of life, probably because they are not so much disabled by their disease at the moment of liver transplantation. The lesser improvement in mental quality of life of FAP patients may be due to their particular psychological profile and greater expectations towards transplantation.</p

The Trypanosoma cruzi Virulence Factor Oligopeptidase B (OPBTc) Assembles into an Active and Stable Dimer

Oligopeptidase B, a processing enzyme of the prolyl oligopeptidase family, is considered as an important virulence factor in trypanosomiasis. Trypanosoma cruzi oligopeptidase B (OPBTc) is involved in host cell invasion by generating a Ca2+-agonist necessary for recruitment and fusion of host lysosomes at the site of parasite attachment. The underlying mechanism remains unknown and further structural and functional characterization of OPBTc may help clarify its physiological function and lead to the development of new therapeutic molecules to treat Chagas disease. In the present work, size exclusion chromatography and analytical ultracentrifugation experiments demonstrate that OPBTc is a dimer in solution, an association salt and pH-resistant and independent of intermolecular disulfide bonds. The enzyme retains its dimeric structure and is fully active up to 42°C. OPBTc is inactivated and its tertiary, but not secondary, structure is disrupted at higher temperatures, as monitored by circular dichroism and fluorescence spectroscopy. It has a highly stable secondary structure over a broad range of pH, undergoes subtle tertiary structure changes at low pH and is less stable under moderate ionic strength conditions. These results bring new insights into the structural properties of OPBTc, contributing to future studies on the rational design of OPBTc inhibitors as a promising strategy for Chagas disease chemotherapy

Potential risk factors for diabetic neuropathy: a case control study

BACKGROUND: Diabetes mellitus type II afflicts at least 2 million people in Iran. Neuropathy is one of the most common complications of diabetes and lowers the patient's quality of life. Since neuropathy often leads to ulceration and amputation, we have tried to elucidate the factors that can affect its progression. METHODS: In this case-control study, 110 diabetic patients were selected from the Shariati Hospital diabetes clinic. Michigan Neuropathic Diabetic Scoring (MNDS) was used to differentiate cases from controls. The diagnosis of neuropathy was confirmed by nerve conduction studies (nerve conduction velocity and electromyography). The multiple factors compared between the two groups included consumption of angiotensin converting enzyme inhibitors (ACEI), blood pressure, serum lipid level, sex, smoking, method of diabetes control and its quality. RESULTS: Statistically significant relationships were found between neuropathy and age, gender, quality of diabetes control and duration of disease (P values in the order: 0.04, 0.04, < 0.001 and 0.005). No correlation was found with any atherosclerosis risk factor (high BP, hyperlipidemia, cigarette smoking). CONCLUSION: In this study, hyperglycemia was the only modifiable risk factor for diabetic neuropathy. Glycemic control reduces the incidence of neuropathy, slows its progression and improves the diabetic patient's quality of life. More attention must be paid to elderly male diabetic patients with poor diabetes control with regard to regular foot examinations and more practical education