Detection of global state predicates

The problem addressed here arises in the context of Meta: how can a set of processes monitor the state of a distributed application in a consistent manner? For example, consider the simple distributed application as shown here. Each of the three processes in the application has a light, and the control processes would each like to take an action when some specified subset of the lights are on. The application processes are instrumented with stubs that determine when the process turns its lights on or off. This information is disseminated to the control processes, each of which then determines when its condition of interest is met. Meta is built on top of the ISIS toolkit, and so we first built the sensor dissemination mechanism using atomic broadcast. Atomic broadcast guarantees that all recipients receive the messages in the same order and that this order is consistent with causality. Unfortunately, the control processes are somewhat limited in what they can deduce when they find that their condition of interest holds

Fast, deterministic computation of the Hermite normal form and determinant of a polynomial matrix

Given a nonsingular $n \times n$ matrix of univariate polynomials over a field $\mathbb{K}$, we give fast and deterministic algorithms to compute its determinant and its Hermite normal form. Our algorithms use $\widetilde{\mathcal{O}}(n^\omega \lceil s \rceil)$ operations in $\mathbb{K}$, where $s$ is bounded from above by both the average of the degrees of the rows and that of the columns of the matrix and $\omega$ is the exponent of matrix multiplication. The soft-$O$ notation indicates that logarithmic factors in the big-$O$ are omitted while the ceiling function indicates that the cost is $\widetilde{\mathcal{O}}(n^\omega)$ when $s = o(1)$. Our algorithms are based on a fast and deterministic triangularization method for computing the diagonal entries of the Hermite form of a nonsingular matrix.Comment: 34 pages, 3 algorithm

Per un linguaggio gender-free uno sguardo agli usi non sessisti della lingua italiana e di quella tedesca

Il saggio illustra gli sforzi che si stanno facendo in Italia e nei paesi tedescofoni per realizzare la parità linguistica tra donna e uomo, combattere l'imperante sessismo e dare maggior visibilità alle persone di sesso femminile

Polioencephalomalacia

Polioencephalomalacia (PEM) is a morphological diagnosis of a lesion in the brain characterized by necrosis of gray matter of the cerebral cortex. However, the term is most often used to indicate a specific central nervous system disease in ruminants assumed to be caused by the disruption of normal thiamine metabolism. The pathological lesion polioencephalomalacia is not caused only by thiamine problems. Therefore, it is important in communications between pathologists practitioners, and producers that everyone realizes how the others are using the term. In some countries such as Great Britain and Australia, the term cerebrocortical necrosis is used instead of PEM

Identification and Characterization of a Salmonella Hyper-biofilm isolate from mouse gallstones

Denman Undergraduate Research Forum, 2nd Place Biological Sciences 2014Center for Microbial Interface Biology Research Symposium, Best Undergraduate Poster Presentation 2014Typhoid fever, a human-specific disease, infects approximately 21 million people each year, resulting in greater than 200,000 deaths. The primary causative agent of typhoid fever is Salmonella enterica serovar Typhi (S. Typhi). It is estimated that 3-5% of people infected with typhoid fever become chronic carriers, who are likely responsible for much of the spread of this disease. Studies have shown a correlation between the typhoid fever carrier state and the presence of gallstones, and this correlation is a result of Salmonella biofilm formation on gallstone surfaces. In the course of a previous long term study of gallstone-bearing mice (a model for S. Typhi human infection), a S. Typhimurium isolate was recovered from a biofilm on a mouse gallstone. This isolate exhibited 3-fold increased biofilm formation over the wild type strain, a phenotype that persisted after 10 passages, suggesting that it was due to a genetic mutation and not a transient change in gene expression. Common biofilm components were tested to identify the key differences causing altered phenotype. Our experiments indicate that the mutant has significant alterations in surface appendages/matrix components that play a role in biofilm development and maintenance. In order to identify the exact mutations responsible for the new phenotype, we sequenced the complete genomes of both wild type Salmonella and our mutant. These sequences identified fourteen genes of interest that may be the cause of the hyperbiofilm phenotype. Mutations in select prioritized genes (envZ, rcsB, flagella-related) have been created and tested for enhanced biofilm capacity. These and other studies will determine if this hyperbiofilm state is due to a directed/selected genetic alteration caused by prolonged incubation in the gallbladder. These data will identify novel targets to interfere with gallstone biofilms, resolve the carrier state and eliminate the spread of typhoid fever.Ohio State Undergraduate Research Office, SOLAR GrantThermo Scientific Pierce ScholarshipOhio State Undergraduate Research Office, Summer FellowshipA one-year embargo was granted for this item.Academic Major: Biomedical Scienc

Fast Computation of Minimal Interpolation Bases in Popov Form for Arbitrary Shifts

We compute minimal bases of solutions for a general interpolation problem, which encompasses Hermite-Pad\'e approximation and constrained multivariate interpolation, and has applications in coding theory and security. This problem asks to find univariate polynomial relations between $m$ vectors of size $\sigma$; these relations should have small degree with respect to an input degree shift. For an arbitrary shift, we propose an algorithm for the computation of an interpolation basis in shifted Popov normal form with a cost of $\mathcal{O}\tilde{~}(m^{\omega-1} \sigma)$ field operations, where $\omega$ is the exponent of matrix multiplication and the notation $\mathcal{O}\tilde{~}(\cdot)$ indicates that logarithmic terms are omitted. Earlier works, in the case of Hermite-Pad\'e approximation and in the general interpolation case, compute non-normalized bases. Since for arbitrary shifts such bases may have size $\Theta(m^2 \sigma)$, the cost bound $\mathcal{O}\tilde{~}(m^{\omega-1} \sigma)$ was feasible only with restrictive assumptions on the shift that ensure small output sizes. The question of handling arbitrary shifts with the same complexity bound was left open. To obtain the target cost for any shift, we strengthen the properties of the output bases, and of those obtained during the course of the algorithm: all the bases are computed in shifted Popov form, whose size is always $\mathcal{O}(m \sigma)$. Then, we design a divide-and-conquer scheme. We recursively reduce the initial interpolation problem to sub-problems with more convenient shifts by first computing information on the degrees of the intermediate bases.Comment: 8 pages, sig-alternate class, 4 figures (problems and algorithms