1,622 research outputs found
Determinants Associated to Zeta Matrices of Posets
We consider the matrix , where the entries of
are the values of the zeta function of the finite poset . We give a
combinatorial interpretation of the determinant of and establish
a recursive formula for this determinant in the case in which is a boolean
algebra.Comment: 14 pages, AMS-Te
Parallel computations on pedigree data through mapping to configurable computing devices
Pedigree data structures have a number of applications in genetics, including the estimation of allelic or haplotype probabilities in humans and agricultural species, and the estimation of breeding values in agricultural species. Sequential algorithms for general purpose CPU-based computers are commonly used, but are inadequate for some tasks on large data sets. We show that pedigree data can be directly represented on Field Programmable Gate Arrays (FPGA), allowing highly efficient massively parallel simulation of the flow of genes. Operating on the whole pedigree in parallel, the transmission of genes can occur for all individuals in a single clock cycle. By using FPGA, the algorithms to estimate inbreeding coefficients and allelic probabilities are shown to operate hundreds to thousands of times faster than the corresponding sequentially based algorithms. Where problems can be largely represented in an integer form, FPGA provide an efficient platform for computations on pedigree data
Continental breakup and UHP rock exhumation in action: GPS results from the Woodlark Rift, Papua New Guinea
We show results from a network of campaign Global Positioning System (GPS) sites in the Woodlark Rift, southeastern Papua New Guinea, in a transition from seafloor spreading to continental rifting. GPS velocities indicate anticlockwise rotation (at 2–2.7°/Myr, relative to Australia) of crustal blocks north of the rift, producing 10–15 mm/yr of extension in the continental rift, increasing to 20–40 mm/yr of seafloor spreading at the Woodlark Spreading Center. Extension in the continental rift is distributed among multiple structures. These data demonstrate that low-angle normal faults in the continents, such as the Mai'iu Fault, can slip at high rates nearing 10 mm/yr. Extensional deformation observed in the D'Entrecasteaux Islands, the site of the world's only actively exhuming Ultra-High Pressure (UHP) rock terrane, supports the idea that extensional processes play a critical role in UHP rock exhumation. GPS data do not require significant interseismic coupling on faults in the region, suggesting that much of the deformation may be aseismic. Westward transfer of deformation from the Woodlark Spreading Center to the main plate boundary fault in the continental rift (the Mai'iu fault) is accommodated by clockwise rotation of a tectonic block beneath Goodenough Bay, and by dextral strike slip on transfer faults within (and surrounding) Normanby Island. Contemporary extension rates in the Woodlark Spreading Center are 30–50% slower than those from seafloor spreading-derived magnetic anomalies. The 0.5 Ma to present seafloor spreading estimates for the Woodlark Basin may be overestimated, and a reevaluation of these data in the context of the GPS rates is warranted
Conodont faunas in the Hughes Creek Shale and Bennett Shale of Riley and Wabaunsee Counties, Kansas
Call number: LD2668 .T4 1965 L77Master of Scienc
Hail to the Chief: Former Law Clerks for William Rehnquist Recall What They Learned and How He Touched Their Lives
Chief Justice William H. Rehnquist, who died Sept. 3, is remembered for his disarming warmth and humor, breadth of knowledge about the law, and insistence that there is life outside the office. Few knew him better than the legions of clerks who tolled with and learned from him. Indeed, the sheer number who attended his funeral testifies to how highly he was regarded. Here, four former clerks from the decades of the 1970s, \u2780s and \u2790s write about their own particular memories of the late chief justice
Hail to the Chief: Former Law Clerks for William Rehnquist Recall What They Learned and How He Touched Their Lives
Chief Justice William H. Rehnquist, who died Sept. 3, is remembered for his disarming warmth and humor, breadth of knowledge about the law, and insistence that there is life outside the office. Few knew him better than the legions of clerks who tolled with and learned from him. Indeed, the sheer number who attended his funeral testifies to how highly he was regarded. Here, four former clerks from the decades of the 1970s, \u2780s and \u2790s write about their own particular memories of the late chief justice
Mediation of the Translocation of nNOSμ During Unloading-Induced Atrophy of Skeletal Muscle via NOX2 Inhibition
Mechanical unloading results in detachment of the mu-splice variant of neuronal nitric oxidase synthase (nNOSμ) from the dystrophin-glycoprotein complex and sarcolemma and translocation to the cytosol. We recently found that reactive oxygen species (ROS) play a role in nNOSμ translocation during unloading and muscle atrophy. NOX2, an isoform of NADPH oxidase and source of ROS, may play a causal role in nNOSμ translocation. The purpose of the study was to determine the effectiveness of NOX2 peptidyl inhibition in reducing the translocation of nNOSμ from the sarcolemma and subsequently soleus CSA. Adult male Fisher 344 rats were randomly assigned to one of three groups: CON (control), HU-S (hind limb unloaded with gp91ds-tat scramble) and HU-G (hind limb unloaded with gp91ds-tat). The hind limb unloading period was 7 days. Mean body weights for CON (353.26 g ± 15.47), HU-S (305.14 g ± 18.18) and HU-G (306.34 g ± 16.84) at the beginning of the experiment were not significantly different. Muscle mass/body mass ratio for the gastrocnemius complex (gastrocnemius, plantaris and soleus) was significantly reduced in HU-S rats (10.08 mg/g ± 0.24) but was maintained in HU-G rats (10.88 mg/g ± 0.47). SMASH analysis revealed that average soleus CSA in HU-G rats (3293.08 μm2 ± 46.82) decreased significantly less than HU-S rats (2606.66 μm2 ± 33.46) compared with ambulatory controls (p \u3e 0.0001). Immunofluorescence and staining of nNOS activity with NADPH Diaphorase of soleus tissue showed considerable loss of sarcolemmal nNOSμ in the HU-S group while the HU-G group revealed substantial maintenance of nNOSμ at the sarcolemma. The results of this study suggest that NOX2 inhibition via gp91ds-tat is effective in reducing the translocation of nNOSμ from the sarcolemma to the cytosol and maintaining CSA of the soleus with mechanical unloading via the inhibition of NOX2
Augmenting the Space Domain Awareness Ground Architecture via Decision Analysis and Multi-Objective Optimization
Purpose — The US Government is challenged to maintain pace as the world’s de facto provider of space object cataloging data. Augmenting capabilities with nontraditional sensors present an expeditious and low-cost improvement. However, the large tradespace and unexplored system of systems performance requirements pose a challenge to successful capitalization. This paper aims to better define and assess the utility of augmentation via a multi-disiplinary study. Design/methodology/approach — Hypothetical telescope architectures are modeled and simulated on two separate days, then evaluated against performance measures and constraints using multi-objective optimization in a heuristic algorithm. Decision analysis and Pareto optimality identifies a set of high-performing architectures while preserving decision-maker design flexibility. Findings — Capacity, coverage and maximum time unobserved are recommended as key performance measures. A total of 187 out of 1017 architectures were identified as top performers. A total of 29% of the sensors considered are found in over 80% of the top architectures. Additional considerations further reduce the tradespace to 19 best choices which collect an average of 49–51 observations per space object with a 595–630 min average maximum time unobserved, providing redundant coverage of the Geosynchronous Orbit belt. This represents a three-fold increase in capacity and coverage and a 2 h (16%) decrease in the maximum time unobserved compared to the baseline government-only architecture as-modeled. Originality/value — This study validates the utility of an augmented network concept using a physics-based model and modern analytical techniques. It objectively responds to policy mandating cataloging improvements without relying solely on expert-derived point solutions
Variations of the McEliece Cryptosystem
Two variations of the McEliece cryptosystem are presented. The first one is
based on a relaxation of the column permutation in the classical McEliece
scrambling process. This is done in such a way that the Hamming weight of the
error, added in the encryption process, can be controlled so that efficient
decryption remains possible. The second variation is based on the use of
spatially coupled moderate-density parity-check codes as secret codes. These
codes are known for their excellent error-correction performance and allow for
a relatively low key size in the cryptosystem. For both variants the security
with respect to known attacks is discussed
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