Carriage of Clostridium perfringens in domestic and farm animals across the central highlands of Colombia: implications for gut health and zoonotic transmission.

Clostridium perfringens inhabits the guts of humans and animal species. C. perfringens can proliferate and express an arsenal of toxins, promoting the development of multiple gut illnesses. Healthy animals carrying C. perfringens represents a risk of transmission to other animals or humans through close contact and an increased likelihood of acquisition of toxin plasmids. The aim of this study was to evaluate the frequency of C. perfringens carriage in domestic and farm animals in the central highlands of Colombia. C. perfringens was detected in six animal species using PCR targeting alpha toxin (cpa) and 16S ribosomal RNA (16S-rRNA) genes from 347 fecal samples collected in two Departments: 177 from farm animals of Boyacá and 170 from domestic animals of both Cundinamarca and Boyacá. The overall frequency of C. perfringens detection was 22.1% (n = 77/347), with the highest frequency observed in cats 34.2% (n = 41/120), followed by dogs 30.0% (n = 15/50). The lowest frequency was detected in ruminants: goats 11.1% (n = 3/27), sheep 8.0% (n = 4/50) and cattle 6.0% (n = 6/50). Domestic animals showed a higher frequency of C. perfringens carriage than farm animals. This difference could be associated with dietary patterns, as domestic animals have diets rich in proteins and carbohydrates, while ruminants have low-carbohydrate diets, resulting in high production of endopeptidase-type enzymes and differences in pH due to the anatomy of gastrointestinal tract, which can influence bacterial proliferation. These findings indicate a potential risk of transmission of C. perfringens among animals and from animals to humans through close contact.

Spondylodiscitis associated with skin lesions caused by Rhizopus in a patient with systemic lupus erythematosus.

Mucormycosis is a serious and rare fungal disease caused by opportunistic fungi of the zygomycete class, order Mucorales. The main clinical presentations are rhinocerebral, pulmonary, cutaneous, gastrointestinal, and disseminated infections. There are few reports in the literature of spondylodiscitis caused by mucormycosis. We report a 53-year-old male patient presenting with subcutaneous nodules and severe low back pain radiating to the lower limbs. The patient had systemic lupus erythematosus (SLE) for 8 years and corticoid-induced diabetes. He had been using 60 mg/day of prednisone in the last year, with a recent pulse therapy regimen with methylprednisolone and cyclophosphamide to control the renal dysfunction. Nuclear magnetic resonance (NMR) of the spine showed spondylodiscitis. The patient underwent spinal arthrodesis and lesion biopsy. The histopathological study of the vertebra reported a necro suppurative inflammation with numerous fungal structures described as a wide range of hyaline hyphae. The histopathology of the cutaneous nodule exhibited an extensive suppurative lesion centered on the subcutaneous tissue, associated with a large amount of hyphae, similar to that found in the spinal lesion, suggestive of mucormycosis. The fungal culture showed the growth of Rhizopus spp. Treatment was performed with amphotericin B lipid complex 5 mg/kg/day for 60 days. After antifungal treatment, there was a progressive reduction in the number of subcutaneous nodules and total improvement of the patient's low back pain, with recovery of his gait. At the 18-month outpatient visit follow-up, the patient was stable and without recurrence. In our case, timely diagnosis enabled the removal of the osteoarticular focus and the targeted therapy resulted in a satisfactory clinical response, without sequelae or complications, despite the patient's underlying immunosuppressed status.

Discrete hydrodynamics near solid planar walls.

We derive, with the projection operator technique, the equations of motion for the time-dependent average of the discrete mass and momentum densities of a fluid confined by planar walls under the assumption that the flow field is translationally invariant along the directions tangent to the walls. Shear flow and sound propagation perpendicular to the walls can be described with the discrete hydrodynamic equations. The interaction with the walls is not given through boundary conditions but rather in terms of impenetrability and friction forces appearing in the discrete hydrodynamic equations. Microscopic expressions for the transport coefficients entering the discrete equations are provided. We further show that the obtained discrete equations can be interpreted as a Petrov-Galerkin finite-element discretization of the continuum equations presented by Camargo et al. [J. Chem. Phys. 148, 064107 (2018)JCPSA60021-960610.1063/1.5010401] when restricted to planar geometries and flows.

Boundary conditions derived from a microscopic theory of hydrodynamics near solids.

The theory of nonlocal isothermal hydrodynamics near a solid object derived microscopically in the study by Camargo et al. [J. Chem. Phys. 148, 064107 (2018)] is considered under the conditions that the flow fields are of macroscopic character. We show that in the limit of macroscopic flows, a simple pillbox argument implies that the reversible and irreversible forces that the solid exerts on the fluid can be represented in terms of boundary conditions. In this way, boundary conditions are derived from the underlying microscopic dynamics of the fluid-solid system. These boundary conditions are the impenetrability condition and the Navier slip boundary condition. The Green-Kubo transport coefficients associated with the irreversible forces that the solid exert on the fluid appear naturally in the slip length. The microscopic expression for the slip length thus obtained is shown to coincide with the one provided originally by Bocquet and Barrat [Phys. Rev. E 49, 3079 (1994)].

Discrete hydrodynamics near solid walls: Non-Markovian effects and the slip boundary condition.

A simple Markovian theory for the prediction of averages and correlations of discrete hydrodynamics near parallel solid walls is presented. The discrete momentum of bins is defined through a finite element basis function. The effect of the walls on the fluid is through irreversible extended friction forces appearing in the very equations of hydrodynamics. The Markovian assumption is critically assessed from the exponential decay of the eigenvalues of the correlation matrix of the discrete transverse momentum. We observe that for bins smaller than molecular dimensions, allowing one to resolve the density layering near the wall, the dynamics near the wall is non-Markovian. Bins larger than the molecular size do behave in a Markovian way. We measure the nonlocal viscosity and frictions kernels that appear in the discrete hydrodynamic equations, which are given in terms of Green-Kubo formulas. They suffer dramatically from the plateau problem. We use a recent procedure for reliably extracting the transport kernels out of the plateau-problematic Green-Kubo formula. With the so-measured transport kernels the nonlocal theory predicts very well the decay of the average of the transverse momentum when the initial velocity profile is a plug flow. The theory allows us to derive the slip boundary condition with microscopic expressions for the slip length and the hydrodynamic position of the wall. The slip boundary condition is not satisfied at the initial stages of the discontinous plug flow, but good agreement is obtained at later stages.

Nanoscale hydrodynamics near solids.

Density Functional Theory (DFT) is a successful and well-established theory for the study of the structure of simple and complex fluids at equilibrium. The theory has been generalized to dynamical situations when the underlying dynamics is diffusive as in, for example, colloidal systems. However, there is no such a clear foundation for Dynamic DFT (DDFT) for the case of simple fluids in contact with solid walls. In this work, we derive DDFT for simple fluids by including not only the mass density field but also the momentum density field of the fluid. The standard projection operator method based on the Kawasaki-Gunton operator is used for deriving the equations for the average value of these fields. The solid is described as featureless under the assumption that all the internal degrees of freedom of the solid relax much faster than those of the fluid (solid elasticity is irrelevant). The fluid moves according to a set of non-local hydrodynamic equations that include explicitly the forces due to the solid. These forces are of two types, reversible forces emerging from the free energy density functional, and accounting for impenetrability of the solid, and irreversible forces that involve the velocity of both the fluid and the solid. These forces are localized in the vicinity of the solid surface. The resulting hydrodynamic equations should allow one to study dynamical regimes of simple fluids in contact with solid objects in isothermal situations.

Estudio de los derechos de los usuarios y consumidores establecidos en la legislación boliviana vigente

Abarca los derechos de los usurios y consumidores y su aplicación en nuestro ordenamiento jurídico actual, por eso se debe considerar que los derechos de los usuarios y consumidores fueron incluidos recién en nuestra Constitución Política del Estado