A mechanism synthesis and modeling for correction of hip dysplasia in medium and large dog breeds

Hip dysplasia is an incurable but treatable disease that affects medium and large dog breeds. It appears as a result of genetic disorders, overweight, and the care given to the dogs. Currently, there are no specialized mechanisms that provide comfort to the life of these pets, while adapting to the canine condition and promoting the use of their hind legs until mobility is completely lost. Therefore, in the present study, a versatile device was synthesized and modeled to help to improve the life quality of dogs, taking as a reference the "German Shepherd" breed. It was designed considering the health and welfare of these animals, taking into account the mobility and safety of their limbs. This device uses a linkage mechanism to provide structural support to the dogs, while allowing for mobility within an specified range of motion. It aims to incorporate a gear and spring system that controls the weight lifted by the device, so that dogs partially use their hind legs. The static and dynamic behavior of this mechanism were mathematically modeled, finding an optimal solution.La displasia de cadera es una enfermedad incurable pero tratable que afecta a razas de perros medianas y grandes. Aparece como resultado de trastornos genéticos, sobrepeso y la atención brindada a los perros. Actualmente, no existen mecanismos especializados que brinden comodidad a la vida de estas mascotas, al tiempo que se adaptan a la condición canina y promueven el uso de sus patas traseras hasta que se pierda por completo la movilidad. Por lo tanto, en el presente estudio, se sintetizó y modeló un dispositivo versátil para ayudar a mejorar la calidad de vida de los perros, tomando como referencia la raza "Pastor Alemán". Fue diseñado teniendo en cuenta la salud y el bienestar de estos animales, considerando la movilidad y la seguridad de sus extremidades. Este dispositivo utiliza un mecanismo de eslabones para proporcionar soporte estructural a los perros, al tiempo que permite la movilidad dentro de un rango de movimiento específico. Proyectando una posible incorporación de un sistema de engranaje y resorte que controla el peso levantado por el dispositivo, para que los perros utilicen parcialmente sus patas traseras. El comportamiento estático y dinámico de este mecanismo fue modelado matemáticamente, encontrando una solución óptima

Spherically symmetric dissipative anisotropic fluids: A general study

The full set of equations governing the evolution of self--gravitating spherically symmetric dissipative fluids with anisotropic stresses is deployed and used to carry out a general study on the behaviour of such systems, in the context of general relativity. Emphasis is given to the link between the Weyl tensor, the shear tensor, the anisotropy of the pressure and the density inhomogeneity. In particular we provide the general, necessary and sufficient, condition for the vanishing of the spatial gradients of energy density, which in turn suggests a possible definition of a gravitational arrow of time. Some solutions are also exhibited to illustrate the discussion.Comment: 28 pages Latex. To appear in Phys.Rev.

A new algorithm for anisotropic solutions

We establish a new algorithm that generates a new solution to the Einstein field equations, with an anisotropic matter distribution, from a seed isotropic solution. The new solution is expressed in terms of integrals of an isotropic gravitational potential; and the integration can be completed exactly for particular isotropic seed metrics. A good feature of our approach is that the anisotropic solutions necessarily have an isotropic limit. We find two examples of anisotropic solutions which generalise the isothermal sphere and the Schwarzschild interior sphere. Both examples are expressed in closed form involving elementary functions only.Comment: 16 pages, to appear in Pramana - J. Phy

High thermal tolerance in high-elevation species and laboratory-reared colonies of tropical bumble bees

Bumble bees are key pollinators with some species reared in captivity at a commercial scale, but with significant evidence of population declines and with alarming predictions of substantial impacts under climate change scenarios. While studies on the thermal biology of temperate bumble bees are still limited, they are entirely absent from the tropics where the effects of climate change are expected to be greater. Herein, we test whether bees' thermal tolerance decreases with elevation and whether the stable optimal conditions used in laboratory-reared colonies reduces their thermal tolerance. We assessed changes in the lower (CTMin) and upper (CTMax) critical thermal limits of four species at two elevations (2600 and 3600 m) in the Colombian Andes, examined the effect of body size, and evaluated the thermal tolerance of wild-caught and laboratory-reared individuals of Bombus pauloensis. We also compiled information on bumble bees' thermal limits and assessed potential predictors for broadscale patterns of variation. We found that CTMin decreased with increasing elevation, while CTMax was similar between elevations. CTMax was slightly higher (0.84°C) in laboratory-reared than in wild-caught bees while CTMin was similar, and CTMin decreased with increasing body size while CTMax did not. Latitude is a good predictor for CTMin while annual mean temperature, maximum and minimum temperatures of the warmest and coldest months are good predictors for both CTMin and CTMax. The stronger response in CTMin with increasing elevation, and similar CTMax, supports Brett's heat-invariant hypothesis, which has been documented in other taxa. Andean bumble bees appear to be about as heat tolerant as those from temperate areas, suggesting that other aspects besides temperature (e.g., water balance) might be more determinant environmental factors for these species. Laboratory-reared colonies are adequate surrogates for addressing questions on thermal tolerance and global warming impacts

Synergistic warm inflation

We consider an alternative warm inflationary scenario in which $n$ scalar fields coupled to a dissipative matter fluid cooperate to produce power--law inflation. The scalar fields are driven by an exponential potential and the bulk dissipative pressure coefficient is linear in the expansion rate. We find that the entropy of the fluid attains its asymptotic value in a characteristic time proportional to the square of the number of fields. This scenario remains nearly isothermal along the inflationary stage. The perturbations in energy density and entropy are studied in the long--wavelength regime and seen to grow roughly as the square of the scale factor. They are shown to be compatible with COBE measurements of the fluctuations in temperature of the CMB.Comment: 13 pages, Revtex 3 To be published in Physical Review

Chiral symmetry breaking and effective lagrangians for softly broken supersymmetric QCD

We study supersymmetric QCD with N_f<N_c in the limit of small supersymmetry-breaking masses and smaller quark masses using the weak-coupling Kahler potential. We calculate the full spectrum of this theory, which manifests a chiral symmetry breaking pattern similar to that caused by the strong interactions of the standard model. We derive the chiral effective lagrangian for the pion degrees of freedom, and discuss the behavior in the formal limit of large squark and gluino masses and for large N_c. We show that the resulting scalings of the pion decay constant and pion masses in these limits differ from those expected in ordinary nonsupersymmetric QCD. Although there is no weak coupling expansion with N_f=N_c, we extend our results to this case by constructing a superfield quantum modified constraint in the presence of supersymmetry breaking.Comment: 16 pages, LaTe

Rapid monitoring of anti-tuberculosis therapy using fluorescein diacetate microscopy: a simple method to determine infectiousness and screen for drug resistance

Background: Tuberculosis treatment and infection control are hampered by difficulty assessing mycobacterial viability to determine infectiousness and early treatment response. TB culture takes weeks; molecular tests are technically demanding; and acid-fast staining cannot differentiate live from dead tuberculosis. / Objectives: To develop and evaluate a simple slide-microscopy test to rapidly determine tuberculosis viability. / Methods: A protocol was optimized to stain viable but not dead tuberculosis in decontaminated sputum dried onto microscope slides and stained with the vital stain fluorescein diacetate (FDA). The reliability of this FDA slide microscopy for determining the concentration of viable tuberculosis in sputum was then compared with quantitative culture. / Results-laboratory evaluation: In untreated patients, tuberculosis auramine staining was unaffected whether sputum was fresh or had been sterilized by boiling, whereas FDA stained only un-boiled, viable tuberculosis. Quantification of viable tuberculosis by culture was reliably predicted by FDA, but not by auramine microscopy. / Results-clinical evaluation : Sequential sputums were collected from 35 patients before and after 3, 6 and 9 days of first-line tuberculosis treatment. Culture quantification of viable mycobacteria in sputum was predicted by slide microscopy with FDA (r2=0.77) but not auramine (r2=0.33). Quantification of viable tuberculosis in sputum by both quantitative culture and FDA microscopy fell 10-100 fold during the first nine days of treatment in all patients with drug-susceptible tuberculosis, whereas there was little change for patients with MDRTB. Specifically, 70% of samples from patients with drug-susceptible tuberculosis had a decline in the FDA count of viable tuberculosis of at least 0.2 logs/treatment-day, compared with none of the samples from MDRTB patients (P1 month required for culture. This simple and inexpensive technique rapidly assessed patient infectiousness on treatment, potentially guiding infection control measures. FDA staining also revealed differences in early treatment response between non-MDR and MDRTB and may allow early field screening for MDRTB and impending treatment failure

The effect of body fat distribution on systemic sclerosis.

Obesity contributes to a chronic proinflammatory state, which is a known risk factor to develop immune-mediated diseases. However, its role in systemic sclerosis (SSc) remains to be elucidated. Therefore, we conducted a two-sample mendelian randomization (2SMR) study to analyze the effect of three body fat distribution parameters in SSc. As instrumental variables, we used the allele effects described for single nucleotide polymorphisms (SNPs) in different genome-wide association studies (GWAS) for SSc, body mass index (BMI), waist-to-hip ratio (WHR) and WHR adjusted for BMI (WHRadjBMI). We performed local (pHESS) and genome-wide (LDSC) genetic correlation analyses between each of the traits and SSc and we applied several Mendelian randomization (MR) methods (i.e., random effects inverse-variance weight, MR-Egger regression, MR pleiotropy residual sum and outlier method and a multivariable model). Our results show no genetic correlation or causal relationship between any of these traits and SSc. Nevertheless, we observed a negative causal association between WHRadjBMI and SSc, which might be due to the effect of gastrointestinal complications suffered by the majority of SSc patients. In conclusion, reverse causality might be an especially difficult confounding factor to define the effect of obesity in the onset of SSc.This work was supported by grant RTI2018101332-B-100 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe” funded by the European Union. Red de Investigación en Inflamación y Enfermedades Reumáticas (RIER) from Instituto de Salud Carlos III (RD16/0012/0013). 115565. LB-C was funded by Grant IJC2018-038026-I funded by MCIN/AEI/10.13039/501100011033. MA-H is a recipient of a Miguel Servet fellowship (CP21/00132) from Instituto de Salud Carlos III (Spanish Ministry of Science and Innovation). EL-I was funded by Grant IJC2019-040080-I funded by MCIN/AEI/10.13039/501100011033. GV-M was funded by Grant PRE2019-087586 funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”

Determination of Pericardial Adipose Tissue Increases the Prognostic Accuracy of Coronary Artery Calcification for Future Cardiovascular Events

Objectives: Pericardial adipose tissue (PAT) is associated with coronary artery plaque accumulation and the incidence of coronary heart disease. We evaluated the possible incremental prognostic value of PAT for future cardiovascular events. Methods: 145 patients (94 males, age 60 10 years) with stable coronary artery disease underwent coronary artery calcification (CAC) scanning in a multislice CT scanner, and the volume of pericardial fat was measured. Mean observation time was 5.4 years. Results: 34 patients experienced a severe cardiac event. They had a significantly higher CAC score (1,708 +/- 2,269 vs. 538 +/- 1,150, p 400, 3.5 (1.9-5.4; p = 0.007) for scores > 800 and 5.9 (3.7-7.8; p = 0.005) for scores > 1,600. When additionally a PAT volume > 200 cm(3) was determined, there was a significant increase in the event rate and relative risk. We calculated a relative risk of 2.9 (1.9-4.2; p = 0.01) for scores > 400, 4.0 (2.1-5.0; p = 0.006) for scores > 800 and 7.1 (4.1-10.2; p = 0.005) for scores > 1,600. Conclusions:The additional determination of PAT increases the predictive power of CAC for future cardiovascular events. PAT might therefore be used as a further parameter for risk stratification. Copyright (C) 2012 S. Karger AG, Base

The effect of body fat distribution on systemic sclerosis.

Congresos y Comunicaciones: Comunicación de Congreso - Conferencia invitada