Vacuum polarization in d+1/2d+{1/2} dimensions

We study the main properties of the one-loop vacuum polarization function ($\Pi_{\alpha \beta}$) for spinor $QED$ in `$d + {1/2}$ dimensions', i.e., with fields defined on ${\mathcal M} \subset {\mathbb R}^{d+1}$ such that ${\mathcal M} = \{(x_0,...,x_d) | x_{d}\geq 0 \}$, with bag-like boundary conditions on the boundary $\partial{\mathcal M} = \{(x_0,...,x_d) | x_{d}= 0 \}$. We obtain an exact expression for the induced current due to an external constant electric field normal to the boundary. We show that, for the particular case of 2+1 dimensions, there is a transverse component for the induced current, which is localized on a region close to $\partial{\mathcal M}$. This current is a parity breaking effect purely due to the boundary.Comment: 11 pages, no figure

RICORS2040 : The need for collaborative research in chronic kidney disease

Chronic kidney disease (CKD) is a silent and poorly known killer. The current concept of CKD is relatively young and uptake by the public, physicians and health authorities is not widespread. Physicians still confuse CKD with chronic kidney insufficiency or failure. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. Thus health authorities may consider CKD a non-issue: very few persons eventually need KRT and, for those in whom kidneys fail, the problem is 'solved' by dialysis or kidney transplantation. However, KRT is the tip of the iceberg in the burden of CKD. The main burden of CKD is accelerated ageing and premature death. The cut-off points for kidney function and kidney damage indexes that define CKD also mark an increased risk for all-cause premature death. CKD is the most prevalent risk factor for lethal coronavirus disease 2019 (COVID-19) and the factor that most increases the risk of death in COVID-19, after old age. Men and women undergoing KRT still have an annual mortality that is 10- to 100-fold higher than similar-age peers, and life expectancy is shortened by ~40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth greatest global cause of death by 2040 and the second greatest cause of death in Spain before the end of the century, a time when one in four Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded Centres for Biomedical Research (CIBER) network structure in Spain. Realizing the underestimation of the CKD burden of disease by health authorities, the Decade of the Kidney initiative for 2020-2030 was launched by the American Association of Kidney Patients and the European Kidney Health Alliance. Leading Spanish kidney researchers grouped in the kidney collaborative research network Red de Investigación Renal have now applied for the Redes de Investigación Cooperativa Orientadas a Resultados en Salud (RICORS) call for collaborative research in Spain with the support of the Spanish Society of Nephrology, Federación Nacional de Asociaciones para la Lucha Contra las Enfermedades del Riñón and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true

Reproducibility in the absence of selective reporting : An illustration from large-scale brain asymmetry research

Altres ajuts: Max Planck Society (Germany).The problem of poor reproducibility of scientific findings has received much attention over recent years, in a variety of fields including psychology and neuroscience. The problem has been partly attributed to publication bias and unwanted practices such as p-hacking. Low statistical power in individual studies is also understood to be an important factor. In a recent multisite collaborative study, we mapped brain anatomical left-right asymmetries for regional measures of surface area and cortical thickness, in 99 MRI datasets from around the world, for a total of over 17,000 participants. In the present study, we revisited these hemispheric effects from the perspective of reproducibility. Within each dataset, we considered that an effect had been reproduced when it matched the meta-analytic effect from the 98 other datasets, in terms of effect direction and significance threshold. In this sense, the results within each dataset were viewed as coming from separate studies in an "ideal publishing environment," that is, free from selective reporting and p hacking. We found an average reproducibility rate of 63.2% (SD = 22.9%, min = 22.2%, max = 97.0%). As expected, reproducibility was higher for larger effects and in larger datasets. Reproducibility was not obviously related to the age of participants, scanner field strength, FreeSurfer software version, cortical regional measurement reliability, or regional size. These findings constitute an empirical illustration of reproducibility in the absence of publication bias or p hacking, when assessing realistic biological effects in heterogeneous neuroscience data, and given typically-used sample sizes

Registro ACESUR: atención de pacientes adultos con crisis epilépticas en servicios de urgencias: diferencias entre primer episodio y recurrencia

Objetivo. Describir las características y la atención recibida de pacientes adultos que consultan por crisis epiléptica (CE) en los servicios de urgencias hospitalarios (SUH), diferenciando entre primera crisis y recurrencia en epiléptico conocido. Método. ACESUR es un registro observacional de cohortes multipropósito, prospectivo y multicéntrico con un muestreo sistemático, los días pares de febrero y julio alternando con los impares de abril y octubre de 2017. Se incluyeron pacientes 18 años con diagnóstico de CE en los SUH. Se recogieron variables clínico-asistenciales de la visita índice de pacientes, distinguiendo entre primera CE y recurrencia en epiléptico. Resultados. El registro ACESUR recogió a 664 pacientes procedentes de 18 SUH españoles, 229 (34, 5%) con primera CE y 435 (65, 5%) con CE recurrentes. Los pacientes con primera CE fueron de mayor edad (p < 0, 001), presentaron motivos de consulta distintos (p < 0, 001) y requirieron más traslados en ambulancia (p < 0, 001). La atención recibida en el SUH fue diferente, en pacientes con primera CE se solicitó con mayor probabilidad una prueba complementaria específica (OR ajustada = 13, 94; IC95%:7, 29-26, 7; p < 0, 001) y se necesitó mayor hospitalización o estancia prolongada en el SUH (OR ajustada = 1, 69; IC95%:1, 11-2, 58; p = 0, 015). No hubo diferencias en cuanto al tratamiento farmacológico en fase aguda ni preventivo (OR ajustada = 1, 40; IC95%:0, 94-2, 09; p = 0, 096). Se inició tratamiento con fármacos antiepiépticos (FAE) en 100 pacientes (43, 7%) tras primera CE y se reinició o modificó añadiendo nuevo FAE en 142 pacientes (32, 6%) con CE recurrentes. Conclusiones. Las características clínicas y la atención recibida de pacientes adultos con primera CE en SUH en España difieren de las recurrencias en epiléptico conocido. Objective. To describe the characteristics of care received by patients who come to the emergency department with a first epileptic seizure versus a recurrent seizure in a patient with diagnosed epilepsy. Methods. ACESUR (Acute Epileptic Seizures in the Emergency Department) is a prospective multicenter, multipurpose registry of cases obtained by systematic sampling on even days in February and July 2017 and on odd days in April and October 2017. Patients were aged 18 years or older and had an emergency department diagnosis of epileptic seizure. We recorded clinical variables and details related to care given during each patient''s visit, including whether the event was a first or recurrent seizure. Results. A total of 664 patients attended by 18 Spanish emergency departments were entered into the ACESUR registry. Two hundred twenty-nine (34.5%) were first seizures and 435 (65.5%) were recurrences. Patients who were attended for first seizures were older, consulted for a wider variety of reasons, and were transported in ambulances (P<.001, all comparisons). Care received differed between patients with first seizures versus recurrent seizures. Specific complementary testing was more likely in patients with first seizures (adjusted odds ratio [aOR], 13.94; 95% CI, 29-26.7; P<.001), and they were more often hospitalized or stayed longer in the emergency department, (aOR, 1.69; 95% CI, 1.11-2.58; P=.015). Pharmacologic treatment did not differ between the groups, either in the acute phase or for prevention (aOR, 1.40; 95% CI, 0.94-2.09; P=.096). Antiepileptic drugs were given to 100 patients (43.7%) after a first seizure and were restarted or changed in 142 patients with recurrent seizure (32.6%). Conclusions. The clinical characteristics of adults attended for a first epileptic seizure differ from those of patients with diagnosed epilepsy who were attended for recurrent seizures in Spain. The care received also differs

First sagittarius A* Event Horizon Telescope results. VI. Testing the black hole metric

Galaxie

A universal power-law prescription for variability from synthetic images of black hole accretion flows

Instrumentatio

First sagittarius A* Event Horizon Telescope results. IV. Variability, morphology, and black hole mass

Galaxie

Millimeter light curves of sagittarius A* observed during the 2017 Event Horizon Telescope campaign

Galaxie