Deterministic Polynomial Time Algorithms for Matrix Completion Problems

We present new deterministic algorithms for several cases of the maximum rank matrix completion problem (for short matrix completion), i.e. the problem of assigning values to the variables in a given symbolic matrix as to maximize the resulting matrix rank. Matrix completion belongs to the fundamental problems in computational complexity with numerous important algorithmic applications, among others, in computing dynamic transitive closures or multicast network codings (Harvey et al SODA 2005, Harvey et al SODA 2006). We design efficient deterministic algorithms for common generalizations of the results of Lovasz and Geelen on this problem by allowing linear functions in the entries of the input matrix such that the submatrices corresponding to each variable have rank one. We present also a deterministic polynomial time algorithm for finding the minimal number of generators of a given module structure given by matrices. We establish further several hardness results related to matrix algebras and modules. As a result we connect the classical problem of polynomial identity testing with checking surjectivity (or injectivity) between two given modules. One of the elements of our algorithm is a construction of a greedy algorithm for finding a maximum rank element in the more general setting of the problem. The proof methods used in this paper could be also of independent interest.Comment: 14 pages, preliminar

Interferon lambda protects the female reproductive tract against Zika virus infection

Zika virus infections can cause devastating congenital birth defects but the underlying interactions with the host immune system are not well understood. Here, the authors examine the immune basis of vaginal protection and susceptibility to Zika viral infection, and identify a hormonal dependent role for interferon-lambda-mediated protection against disease

Catalase as a sulfide-sulfur oxido-reductase: An ancient (and modern?) regulator of reactive sulfur species (RSS)

Catalase is well-known as an antioxidant dismutating H2O2 to O2 and H2O. However, catalases evolved when metabolism was largely sulfur-based, long before O2 and reactive oxygen species (ROS) became abundant, suggesting catalase metabolizes reactive sulfide species (RSS). Here we examine catalase metabolism of H2Sn, the sulfur analog of H2O2, hydrogen sulfide (H2S) and other sulfur-bearing molecules using H2S-specific amperometric electrodes and fluorophores to measure polysulfides (H2Sn; SSP4) and ROS (dichlorofluorescein, DCF). Catalase eliminated H2Sn, but did not anaerobically generate H2S, the expected product of dismutation. Instead, catalase concentration- and oxygen-dependently metabolized H2S and in so doing acted as a sulfide oxidase with a P50 of 20 mmHg. H2O2 had little effect on catalase-mediated H2S metabolism but in the presence of the catalase inhibitor, sodium azide (Az), H2O2 rapidly and efficiently expedited H2S metabolism in both normoxia and hypoxia suggesting H2O2 is an effective electron acceptor in this reaction. Unexpectedly, catalase concentration-dependently generated H2S from dithiothreitol (DTT) in both normoxia and hypoxia, concomitantly oxidizing H2S in the presence of O2. H2S production from DTT was inhibited by carbon monoxide and augmented by NADPH suggesting that catalase heme-iron is the catalytic site and that NADPH provides reducing equivalents. Catalase also generated H2S from garlic oil, diallyltrisulfide, thioredoxin and sulfur dioxide, but not from sulfite, metabisulfite, carbonyl sulfide, cysteine, cystine, glutathione or oxidized glutathione. Oxidase activity was also present in catalase from Aspergillus niger. These results show that catalase can act as either a sulfide oxidase or sulfur reductase and they suggest that these activities likely played a prominent role in sulfur metabolism during evolution and may continue do so in modern cells as well. This also appears to be the first observation of catalase reductase activity independent of peroxide dismutation

Study of Uncontrolled Cement Dust Exposure and Its Prolonged Effects on Glycemic Status and Renal Function Markers among Male Cement Handlers at Dalmia Cement Factory

Environmental pollutants cause adverse impact on human body vital organs and ultimately leads to disease. It is of utmost importance to recognize those components or risk factors within individual’s surrounding that are associated with it. The current study has explored the persisting effects of cement dust on glycemic status and selected renal function markers between male cement handlers at Dalmia Cement Factory. This study revealed that prolonged and recurrent exposures, contingent on the length of time and sensitivity of factory workers exposed to cement dust particles, have caused deleterious complications and deteriorating health conditions particularly seen in their glycemic status and selected renal function markers. The finding results of this investigation demonstrated that uncontrolled cement dust- exposure causes significant commonness of type 2 diabetes mellitus (T2DM), prediabetes and derailed renal function markers among cement handlers (CH). The levels of HbA1c, 24 hours urinary sugar, blood urea, creatinine, bi-carbonate and serum electrolytes (Na+ and K+) is significantly increased in cement handlers as compared to non-cement handlers (NCH) as controls. In addition to this significant difference was recorded in the blood pressure levels among exposed group when compared with control subjects at Dalmia Cement Factory. The hyperglycemic and nephrotoxic consequences of cement dust and its potential for development of insulin resistance, T2DM disease and renal insufficiency might exacerbate if the exposure to cement dust among cement handlers is not controlled.&nbsp

SNACS Annotation of Case Markers and Adpositions in Hindi

We present in-progress annotation of semantic relations expressed through adpositions and case markers in a Hindi corpus. We used the multilingual SNACS annotation scheme, which has been applied to a variety of typologically diverse languages. Annotation problems in Hindi are examined and used to suggest changes to SNACS. We look towards finalizing the corpus and using it for future work in typology and semantic role-dependent tasks

Elegant Aging Through Endocrine Optimization

Elegant Aging Through Endocrine Optimizatio

Direct N-body Kernels for Multicore Platforms

Abstract—We present an inter-architectural comparison of single- and double-precision direct n-body implementations on modern multicore platforms, including those based on the Intel Nehalem and AMD Barcelona systems, the Sony-Toshiba-IBM PowerXCell/8i processor, and NVIDIA Tesla C870 and C1060 GPU systems. We compare our implementations across platforms on a variety of proxy measures, including performance, coding complexity, and energy efficiency. I