607 research outputs found

    Masses and Interactions of q-Fermionic Knots

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    The q-electroweak theory suggests a description of elementary particles as solitons labelled by the irreducible representations of SU_q(2). Since knots may also be labelled by the irreducible representations of SU_q(2), we study a model of elementary particles based on a one-to-one correspondence between the four families of Fermions (leptons, neutrinos, (-1/3) quarks, (2/3) quarks) and the four simplest knots (trefoils). In this model the three particles of each family are identified with the ground and first two excited states of their common trefoil. Guided by the standard electroweak theory we calculate conditions restricting the masses of the fermions and the interactions between them. In its present form the model predicts a fourth generation of fermions as well as a neutrino spectrum. The same model with q almost equal to 1 is compatible with the Kobayashi-Maskawa matrix. Depending on the test of these predictions, the model may be refined.Comment: 40 pages, 2 figures, latex forma

    Diabetic kidney disease in type 2 diabetes: a consensus statement from the Swiss Societies of Diabetes and Nephrology.

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    Diabetic kidney disease is highly prevalent in patients with type 2 diabetes and is a major cause of end-stage renal disease in Switzerland. Patients with diabetic kidney disease are among the most complex patients in diabetes care. They require a multifactorial and multidisciplinary approach with the goal to slow the decline in glomerular filtration rate (GFR) and cardiovascular morbidity. With this consensus we propose an evidence-based guidance to health care providers involved in the care of type 2 diabetic patients with diabetic kidney disease.First, there is a need to increase physician awareness and improve screening for diabetic kidney disease as early intervention may improve clinical outcomes and the financial burden. Evaluation of estimated GFR (eGFR) and spot urine albumin/creatinine ratio is recommended at least annually. Once it is diagnosed, glucose control and optimisation of blood pressure control with renin-angiotensin system blockers have been recommended as mainstay management of diabetic kidney disease for more than 20 years. Recent, high quality randomised controlled trials have shown that sodium-glucose cotransporter-2 (SGLT2) inhibition slows eGFR decline and cardiovascular events beyond glucose control. Likewise, mineralocorticoid receptor antagonism with finerenone has cardiorenal protective effects in diabetic kidney disease. Glucagon-like peptide-1 (GLP1) receptor agonists improve weight loss if needed, and decrease albuminuria and cardiovascular morbidity. Lipid control is also important to decrease cardiovascular events. All these therapies are included in the treatment algorithms proposed in this consensus. With advancing kidney failure, other challenges may rise, such as hyperkalaemia, anaemia and metabolic acidosis, as well as chronic kidney disease-mineral and bone disorder. These different topics and treatment strategies are discussed in this consensus. Finally, an update on diabetes management in renal replacement therapy such as haemodialysis, peritoneal dialysis and renal transplantation is provided. With the recent developments of efficient therapies for diabetic kidney disease, it has become evident that a consensus document is necessary. We are optimistic that it will significantly contribute to a high-quality care for patients with diabetic kidney disease in Switzerland in the future

    A genetically-informed population viability analysis reveals conservation priorities for an isolated population of Hyla arborea

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    Population Viability Analysis (PVA) is a commonly used tool to predict the fate of endangered populations. However, although amphibians are the most endangered group of vertebrates, PVAs have so far been underrepresented in their conservation management. In the last decades, the European tree frog (Hyla arborea) has experienced drastic declines mainly caused by habitat fragmentation and loss of suitable breeding sites. In the present study, we used the PVA software VORTEX to predict the viability of a H. arborea population, comprising about 70 adults and inhabiting an isolated pond in the region of Hannover (Germany), by combining life history data with genotypic information derived from eight polymorphic microsatellite markers. The PVA revealed a high probability of extinction over the next 50 years, with juvenile survival being a crucial demographic parameter for population persistence. Simulated immigration through metapopulation processes or population supplementation prevented genetic erosion, and markedly increased the probability of population survival. Future management interventions should consider pond management to enhance survival at early stages, and the creation of migration corridors to allow connectivity with adjacent demes and/or the translocation of individuals. To our knowledge, this is one of the first studies which applies a genetically-informed PVA to the management of endangered anuran amphibians

    Acute Renal Failure on Immune Reconstitution in an HIV-Positive Patient with Miliary Tuberculosis

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    Immune reconstitution syndrome following HAART in human immunodeficiency virus (HIV)-infected patients is characterized by inflammatory worsening of organ functions despite improvement in HIV surrogate markers of HIV infection. We describe a patient with miliary tuberculosis and urinary shedding of acid fast bacilli who developed acute renal failure 8 weeks after initiation of antituberculosis therapy and 6 weeks after initiation of HAART. The diagnostic workup and further course of disease implicated immune reconstitution syndrome as the cause of acute renal failur

    A toy model of the five-dimensional universe with the cosmological constant

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    A value of the cosmological constant in a toy model of the five-dimensional universe is calculated in such a manner that it remains in agreement with both astronomical observations and the quantum field theory concerning the zero-point fluctuations of the vacuum. The (negative) cosmological constant is equal to the inverse of the Planck length squared, which means that in the toy model the vanishing of the observed value of the cosmological constant is a consequence of the existence of an energy cutoff exactly at the level of the Planck scale. In turn, a model for both a virtual and a real particle-antiparticle pair is proposed which describes properly some energetic properties of both the vacuum fluctuations and created particles, as well as it allows one to calculate the discrete "bare" values of an elementary-particle mass, electric charge and intrinsic angular momentum (spin) at the energy cutoff. The relationships between the discussed model and some phenomena such as the Zitterbewegung and the Unruh-Davies effect are briefly analyzed, too. The proposed model also allows one to derive the Lorentz transformation and the Maxwell equations while considering the properties of the vacuum filled with the sea of virtual particles and their antiparticles. Finally, the existence of a finite value of the vacuum-energy density resulting from the toy model leads us to the formulation of dimensionless Einstein field equations which can be derived from the Lagrangian with a dimensionless (naively renormalized) coupling constant.Comment: 52 pages, 1 figure; a post-final, rewritten version with a number of new remarks and conclusion

    Kinematics and hydrodynamics of spinning particles

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    In the first part (Sections 1 and 2) of this paper --starting from the Pauli current, in the ordinary tensorial language-- we obtain the decomposition of the non-relativistic field velocity into two orthogonal parts: (i) the "classical part, that is, the 3-velocity w = p/m OF the center-of-mass (CM), and (ii) the so-called "quantum" part, that is, the 3-velocity V of the motion IN the CM frame (namely, the internal "spin motion" or zitterbewegung). By inserting such a complete, composite expression of the velocity into the kinetic energy term of the non-relativistic classical (i.e., newtonian) lagrangian, we straightforwardly get the appearance of the so-called "quantum potential" associated, as it is known, with the Madelung fluid. This result carries further evidence that the quantum behaviour of micro-systems can be adirect consequence of the fundamental existence of spin. In the second part (Sections 3 and 4), we fix our attention on the total 3-velocity v = w + V, it being now necessary to pass to relativistic (classical) physics; and we show that the proper time entering the definition of the four-velocity v^mu for spinning particles has to be the proper time tau of the CM frame. Inserting the correct Lorentz factor into the definition of v^mu leads to completely new kinematical properties for v_mu v^mu. The important constraint p_mu v^mu = m, identically true for scalar particles, but just assumed a priori in all previous spinning particle theories, is herein derived in a self-consistent way.Comment: LaTeX file; needs kapproc.st
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