Three-fold way to extinction in populations of cyclically competing species

Species extinction occurs regularly and unavoidably in ecological systems. The time scales for extinction can broadly vary and inform on the ecosystem's stability. We study the spatio-temporal extinction dynamics of a paradigmatic population model where three species exhibit cyclic competition. The cyclic dynamics reflects the non-equilibrium nature of the species interactions. While previous work focusses on the coarsening process as a mechanism that drives the system to extinction, we found that unexpectedly the dynamics to extinction is much richer. We observed three different types of dynamics. In addition to coarsening, in the evolutionary relevant limit of large times, oscillating traveling waves and heteroclinic orbits play a dominant role. The weight of the different processes depends on the degree of mixing and the system size. By analytical arguments and extensive numerical simulations we provide the full characteristics of scenarios leading to extinction in one of the most surprising models of ecology

Gating of high-mobility two-dimensional electron gases in GaAs/AlGaAs heterostructures

We investigate high-mobility two-dimensional electron gases in AlGaAs heterostructures by employing Schottky-gate-dependent measurements of the samples' electron density and mobility. Surprisingly, we find that two different sample configurations can be set in situ with mobilities diering by a factor of more than two in a wide range of densities. This observation is discussed in view of charge redistributions between the doping layers and is relevant for the design of future gateable high-mobility electron gases

Influence Of Nanopolymers With Different End‐Functionalities On Platelets And Coagulation. An Ex‐Vivo Study

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106058/1/jth03252.pd

Hyper parathyroidisim jaw tumor syndrome: a rare condition of incongruous features

Background: Hyperparathyroidism-Jaw Tumor (HPT-JT) syndrome is a rare genetic disorder bearing both a germline and a somatic CDC73 mutation (formerly known as HRPT2), which has been mapped to chromosome 1q25-q31. The association of jaw ossifying fibroma with primary hyperparathyroidisim (PHPT) is typical of HPT-JT. It may also include cystic and neoplastic renal abnormalities and uterine tumors.Case Details: Here, we report a case of HPT-JT with an initial presentation of declination in reproductive fitness. Extensive literature search and thorough investigation helped us parturitate the underlying syndrome, thereby predictively improving the prognosis.Conclusion: The features of HPT-JT are clinically difficult to ascertain because the parathyroid disease, ossifying fibroma in the jaw and other abnormalities, often occurs asynchronously and may be diagnosed and treated separately.Keywords: Hyperparathyroidism, HPT-JT, Ossifying fibroma, Syndrom

Potential effect of metformin and vildagliptin against isoniazid induced hepatotoxicity in Wistar albino rats

Background: Metformin and vildagliptin both are anti-diabetic agent and they play an important role in diabetic patients as they reduce blood glucose levels. Studies revealed that both metformin and vildagliptin has the ability to promote beta cell neogenesis and regeneration. So, our study was planned to explore the hepatoprotective potential of metformin and vildagliptin in Wistar albino rats exposed to isoniazid (INH) induced hepatotoxicity. Methods: Wistar albino rats weighing 150-180 g were obtained from Mass Biotech, Chengalpattu, Tamil Nadu. The animals were divided into 6 groups (n=6) and further treated orally against INH-induced hepatotoxicity except normal control group. group 1: normal control, group 2: INH, group 3: metformin+INH, group 4: vildagliptin+INH, group 5: metformin amd vildagliptin+INH, group 6: silymarin. Results: In the present study, INH was administered for 21 days to induce liver damage to rats except normal group. Each group was treated with metformin, vildagliptin, (metformin+vildagliptin) combination and silymarin half an hour before INH challenge. On the 22nd day the blood samples were collected to estimate the AST and ALT levels. Immediately after blood collection the animals were sacrificed, the livers were removed and kept in 10% formalin for histopathological examination. Conclusions: The study found that metformin, vildagliptin, and their combination showed hepatoprotective activity against INH-induced hepatotoxicity. The combination of metformin+vildagliptin was the most effective. Metformin reduces oxidative stress, while vildagliptin balances pro-oxidant and anti-oxidant levels, contributing to their hepatoprotective effects. This suggests their potential usefulness in drug-induced hepatotoxicity

Guaranteed clustering and biclustering via semidefinite programming

Identifying clusters of similar objects in data plays a significant role in a wide range of applications. As a model problem for clustering, we consider the densest k-disjoint-clique problem, whose goal is to identify the collection of k disjoint cliques of a given weighted complete graph maximizing the sum of the densities of the complete subgraphs induced by these cliques. In this paper, we establish conditions ensuring exact recovery of the densest k cliques of a given graph from the optimal solution of a particular semidefinite program. In particular, the semidefinite relaxation is exact for input graphs corresponding to data consisting of k large, distinct clusters and a smaller number of outliers. This approach also yields a semidefinite relaxation for the biclustering problem with similar recovery guarantees. Given a set of objects and a set of features exhibited by these objects, biclustering seeks to simultaneously group the objects and features according to their expression levels. This problem may be posed as partitioning the nodes of a weighted bipartite complete graph such that the sum of the densities of the resulting bipartite complete subgraphs is maximized. As in our analysis of the densest k-disjoint-clique problem, we show that the correct partition of the objects and features can be recovered from the optimal solution of a semidefinite program in the case that the given data consists of several disjoint sets of objects exhibiting similar features. Empirical evidence from numerical experiments supporting these theoretical guarantees is also provided

Analysis of interaction between Arbuscular Mycorrhizal fungi and their Helper bacteria by MILPA model

Many recent researches carried out the research in mycorrhizal symbiosis to improve crop growth in the agriculture but they differ in their approaches like crops and the agricultural perspectives. The study focused on the interaction of Arbuscular mycorrhizal (AM) fungi and helper bacteria, influence maize growth through milpa as a model system to analyze soil enzyme activity of acid, alkaline phosphatase and signaling molecule of phospholipids fatty acid (PLFA) profile. Bioinoculants plays an important role in plant growth like nutrient mobilization, biocontrol and prevent the plants from stress. The maize crops were treated with bio inoculants such as Azospirillum, Azotobacter, Rhizobium,Pseudomonas and AM fungi. Significant diverse effects were observed with bioinoculants in the crops compared to control crop. The number spores formed was proportional to the rate of colonization.AM fungi association in plant roots helps the plants in nutrient uptake especially phosphorus (P) from soil materials. The enzyme activities were also found to influence the growth of the plant and phospholipids fatty acid (PLFA) profile influences the interaction between bacterium and AMF. Plant and phospholipids fatty acid analysis is asensitive and accurate method in determining microbial community structures, because it depends on living cell contents of microorganisms under in situ conditions. It confirmed with gas chromatographic analysis of PLFA to determination of the structure and total biomass of microbial community in treated soil samples