The Intrinsic Fundamental Group of a Linear Category

We provide an intrinsic definition of the fundamental group of a linear category over a ring as the automorphism group of the fibre functor on Galois coverings. If the universal covering exists, we prove that this group is isomorphic to the Galois group of the universal covering. The grading deduced from a Galois covering enables us to describe the canonical monomorphism from its automorphism group to the first Hochschild-Mitchell cohomology vector space.Comment: Final version, to appear in Algebras and Representation Theor

Nosema bombi (Microsporidia: Nosematidae) and trypanosomatid prevalence in spring bumble bee queens (Hymenoptera: Apidae: Bombus) in Kansas

Citation: Tribodi, A., Cibils-Stewart, X., McCornack, B., & Szlanski, A. (2014). Nosema bombi (Microsporidia: Nosematidae) and Trypanosomatid Prevalence in Spring Bumble Bee Queens (Hymenoptera: Apidae: Bombus) in Kansas. Journal of the Entomological Society, 87(2), 225-233. https://doi.org/10.2317/JKES130730.1Several species of bumble bees are declining in the United States; these declining populations often show higher prevalence of Nosema bombi, a microsporidian pathogen. To date, surveys of bumble bee pathogens in the United States have only been conducted on workers and males, yet the health of a population is ultimately dependent on the success of colony-founding queens. We conducted a molecular-diagnostic survey of the prevalence of N. bombi and trypanosomatids, such as Crithidia bombi, in six species of spring queens (n  =  142) collected in 2011 and 2013 at three sites in central Kansas. Nosema bombi was found in 27% of Bombus pensylvanicus and 13% of B. auricomus but was not found in the other species sampled. Trypanosomatids were only found in B. pensylvanicus (9%) during the May 2013 sampling period. The high prevalence of N. bombi in B. pensylvanicus is consistent with other surveys for this pathogen in other castes, but the high prevalence of N. bombi in B. auricomus is a novel finding. Although the conservation status of B. auricomus has not been thoroughly assessed, two recently published surveys showed that B. auricomus were less common in portions of the species' range. Based on those findings and an oft-cited link between N. bombi prevalence and bumble bee species' decline (e.g., B. pensylvanicus) in other studies, our findings suggest B. auricomus populations in Kansas may warrant further scrutiny

Flow equations for Hamiltonians: Contrasting different approaches by using a numerically solvable model

To contrast different generators for flow equations for Hamiltonians and to discuss the dependence of physical quantities on unitarily equivalent, but effectively different initial Hamiltonians, a numerically solvable model is considered which is structurally similar to impurity models. By this we discuss the question of optimization for the first time. A general truncation scheme is established that produces good results for the Hamiltonian flow as well as for the operator flow. Nevertheless, it is also pointed out that a systematic and feasible scheme for the operator flow on the operator level is missing. For this, an explicit analysis of the operator flow is given for the first time. We observe that truncation of the series of the observable flow after the linear or bilinear terms does not yield satisfactory results for the entire parameter regime as - especially close to resonances - even high orders of the exact series expansion carry considerable weight.Comment: 25 pages, 10 figure

Anestesia sub-Tenoniana versus Anestesia Peribulbar en Cirugía Extracapsular de Catarata

Con el objeto de comparar la efectividad de la anestesia sub-tenoniana con la peribulbar en cirugía extracapsular de catarata, se seleccionaron aleatoriamente en la Fundación Visión de Asunción (Paraguay), 35 pacientes adultos para recibir anestesia sub-tenoniana (8 mujeres y 9varones) o anestesia peribulbar (13 mujeres y 5 varones). La presión intraocular (PIO) antes, al primer y a los diez minutos de la anestesia fue medida, como así también la motilidad de los músculos rectos a los 10 minutos de la anestesia, el grado de dolor del paciente durante y altérmino de la cirugía y el grado de satisfacción del cirujano. La elevación de la PIO con la peribulbar fue estadísticamente significativa (p<0,008) al minuto de la inyección, retornando a los diez minutos a los niveles basales en ambos grupos. Diez minutos después de la aplicación delanestésico se encontraron diferencias estadísticamente significativas entre los grupos en la elevación (p=0,005), abducción (p=0,02) y depresión (p=0,01) de los músculos rectos; como así también en los niveles de dolor intraquirúrgico (p=0,04), pero no en los niveles de dolor debido a laaplicación de la anestesia o en el grado de satisfacción del cirujano. En conclusión, la anestesia subtenoniana produjo menor elevación de la PIO que la peribulbar y la aquinesia parcial obtenida con ella no fue un factor limitante para el cirujano. Aunque mayor porcentaje del grupo de la anestesia sub-tenoniana refirió algún grado de dolor intraquirúrgico, fue considerado tolerable debido a que no fue necesario refuerzo del anestésico

Clostridium Perfringens: agente etiologico de queratitis infecciosa

Clostridium perfringens es un raro agente causal de queratitis infecciosa, usualmente produce enfermedades necrotizantes severas. Presentación del caso: Agricultor de 32 años, procedente de General Artigas, Paraguay consultó en un servicio debido a un trauma con metal, cable en ojo derecho. Fue tratado con cicloplégico, AINES (antiinflamatorio no esteroideo) y aplicación de lente de contacto terapéutico. Después de 18 días sin mejoría acudió al Departamento de Oftalmología del Hospital de Clínicas de la Universidad Nacional de Asunción. El paciente presentó ausencia de percepción luminosa en el ojo afecto, quemosis, hipopion y ulcera central de cornea (5 mm). Se tomó muestra por raspado de cornea y el examen directo reveló bacilos Gram positivos. Se realizó cultivo en placas de agar sangre, agar chocolate y en caldo tioglicolato incubados a 37ºC y en agar Sabouraud incubados a 28 ºC. Después del informe laboratorial se inició tratamiento con cefazolina 50 mg/ml y gentamicina 14 mg/ml cada hora. Del medio de enriquecimiento fue aislado Clostridium perfringens después de tres días. Desafortunadamente el paciente no asistió a su control

Small denominators, frequency operators, and Lie transforms for nearly integrable quantum spin systems

Based on the previously proposed notions of action operators and of quantum integrability, frequency operators are introduced in a fully quantum-mechanical setting. They are conceptually useful because another formulation can be given to unitary perturbation theory. When worked out for quantum spin systems, this variant is found to be formally equivalent to canonical perturbation theory applied to nearly integrable systems consisting of classical spins. In particular, it becomes possible to locate the quantum-mechanical operator-valued equivalent of the frequency denominators that may cause divergence of the classical perturbation series. The results that are established here link the concept of quantum-mechanical integrability to a technical question, namely, the behavior of specific perturbation series

Graded D-branes and skew-categories

I describe extended gradings of open topological field theories in two dimensions in terms of skew categories, proving a result which alows one to translate between the formalism of graded open 2d TFTs and equivariant cyclic categories. As an application of this formalism, I describe the open 2d TFT of graded D-branes in Landau-Ginzburg models in terms of an equivariant cyclic structure on the triangulated category of `graded matrix factorizations' introduced by Orlov. This leads to a specific conjecture for the Serre functor on the latter, which generalizes results known from the minimal and Calabi-Yau cases. I also give a description of the open 2d TFT of such models which manifestly displays the full grading induced by the vector-axial R-symmetry group.Comment: 37 page