Search for Gamma-Ray Spectral Lines from Dark Matter Annihilation up to 100 TeV toward the Galactic Center with MAGIC.

Linelike features in TeV γ rays constitute a "smoking gun" for TeV-scale particle dark matter and new physics. Probing the Galactic Center region with ground-based Cherenkov telescopes enables the search for TeV spectral features in immediate association with a dense dark matter reservoir at a sensitivity out of reach for satellite γ-ray detectors, and direct detection and collider experiments. We report on 223 hours of observations of the Galactic Center region with the MAGIC stereoscopic telescope system reaching γ-ray energies up to 100 TeV. We improved the sensitivity to spectral lines at high energies using large-zenith-angle observations and a novel background modeling method within a maximum-likelihood analysis in the energy domain. No linelike spectral feature is found in our analysis. Therefore, we constrain the cross section for dark matter annihilation into two photons to ⟨σv⟩≲5×10^{-28} cm^{3} s^{-1} at 1 TeV and ⟨σv⟩≲1×10^{-25} cm^{3} s^{-1} at 100 TeV, achieving the best limits to date for a dark matter mass above 20 TeV and a cuspy dark matter profile at the Galactic Center. Finally, we use the derived limits for both cuspy and cored dark matter profiles to constrain supersymmetric wino models.

Bounds on Lorentz Invariance Violation from MAGIC Observation of GRB 190114C.

On January 14, 2019, the Major Atmospheric Gamma Imaging Cherenkov telescopes detected GRB 190114C above 0.2 TeV, recording the most energetic photons ever observed from a gamma-ray burst. We use this unique observation to probe an energy dependence of the speed of light in vacuo for photons as predicted by several quantum gravity models. Based on a set of assumptions on the possible intrinsic spectral and temporal evolution, we obtain competitive lower limits on the quadratic leading order of speed of light modification.

Differences in clinical manifestations and increased severity of systemic lupus erythematosus between two groups of Hispanics: European Caucasians versus Latin American mestizos (data from the RELESSER registry).

BACKGROUND: Systemic lupus erythematosus (SLE) is regarded as a prototype autoimmune disease because it can serve as a means for studying differences between ethnic minorities and sex. Traditionally, all Hispanics have been bracketed within the same ethnic group, but there are differences between Hispanics from Spain and those from Latin America, not to mention other Spanish-speaking populations. OBJECTIVES: This study aimed to determine the demographic and clinical characteristics, severity, activity, damage, mortality and co-morbidity of SLE in Hispanics belonging to the two ethnic groups resident in Spain, and to identify any differences. METHODS: This was an observational, multi-centre, retrospective study. The demographic and clinical variables of patients with SLE from 45 rheumatology units were collected. The study was conducted in accordance with Good Clinical Practice guidelines. Hispanic patients from the registry were divided into two groups: Spaniards or European Caucasians (EC) and Latin American mestizos (LAM). Comparative univariate and multivariate statistical analyses were carried out. RESULTS: A total of 3490 SLE patients were included, 90% of whom were female; 3305 (92%) EC and 185 (5%) LAM. LAM patients experienced their first lupus symptoms four years earlier than EC patients and were diagnosed and included in the registry younger, and their SLE was of a shorter duration. The time in months from the first SLE symptoms to diagnosis was longer in EC patients, as were the follow-up periods. LAM patients exhibited higher prevalence rates of myositis, haemolytic anaemia and nephritis, but there were no differences in histological type or serositis. Anti-Sm, anti-Ro and anti-RNP antibodies were more frequently found in LAM patients. LAM patients also had higher levels of disease activity, severity and hospital admissions. However, there were no differences in damage index, mortality or co-morbidity index. In the multivariate analysis, after adjusting for confounders, in several models the odds ratio (95% confidence interval) for a Katz severity index >3 in LAM patients was 1.45 (1.038-2.026; p = 0.02). This difference did not extend to activity levels (i.e. SLEDAI >3; 0.98 (0.30-1.66)). CONCLUSION: SLE in Hispanic EC patients showed clinical differences compared to Hispanic LAM patients. The latter more frequently suffered nephritis and higher severity indices. This study shows that where lupus is concerned, not all Hispanics are equal.

Black hole physics. Black hole lightning due to particle acceleration at subhorizon scales.

Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescopes, revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20% of the gravitational radius of its central black hole. We suggest that the emission is associated with pulsar-like particle acceleration by the electric field across a magnetospheric gap at the base of the radio jet.

[Changes in carbohydrate metabolism during the administration of progestational hormones]. / Modificaciones del metabolismo de los hidratos de carbono durante la administración de progestágenos.

PIP: Changes in the levels of plasma glucose and serum insulin and growth hormone after oral and iv administration of glucose and infusion of arginine in a group of 35 carefully selected normal women were studied. The tests were performed before and during the administration of progestins of the sequential and combination type (Oracon and Ovulen, respectively), during the 2nd or 3rd cycle of treatment. The results showed that both types of treatment produced a significant increase in the serum insulin and growth hormone levels, while the plasma glucose level remained unaltered in the various tests. It would appear that these drugs produce an increase in peripheral resistance to insulin, since the insulin-glucose index rose in the growth hormone level, may also be due to an antiinsulin action and/or to changes in the production of insulin directly caused by the drugs.^ieng

Serum insulin and growth hormone responses to arginine infusion before and during treatment with contraceptive steroids.

PIP: To determine the responses of plasma glucose, serum growth hormone (HGH), and serum insulin to arginine infusion before and during cyclic administration of 100 mcg ethinyl estradiol 3-methyl ether (mestranol) plus 1 mg ethynodiol diacetate (Ovulen) 12 young, healthy, nonobese women (at least 6 weeks postpartum with no family or obstetric history suggestive of diabetes) were observed. The mean cumulative glucose was unchanged, while the mean cumulative insulin (p less than .05 at 30 minutes) and HGH increased (p less than .05 at 30 minutes and p less than .01 at 120 minutes) during 2 hour tests. These data indicate that contraceptive steroids induced a peripheral antiinsulin effect which may be due to increased HGH secretion. A direct antiinsulin action or insulinogenic effect of steroids remains to be determined.^ieng

Timing and sequence of resuming ovulation and menstruation after childbirth.

Abstract This report presents results from a prospective study of post-partum physiology conducted by the Obstetric Department of the Catholic University of Chile during 1965-68. The study was undertaken to gain more detailed knowledge than is currently available about the relationship between a woman's lactation experience and the return of her post-partum reproductive function. 200 mothers were successfully followed and information collected about their intervals from childbirth to first ovulation and to first bleeding day, together with a detailed history of breast feeding. In these histories, days of 'full breast feeding' (infant exclusively breast-fed) are distinguished from days of 'partial breast feeding' (infant given supplementary nutrition besides breast milk). Elaborate pains were taken to establish the date of first ovulation, four different techniques being used concurrently during a series of weekly contacts with each patient.

Study designs and statistical methods in rheumatological journals: an international comparison.

In order to determine the characteristics of papers published in the rheumatological literature, we have conducted a survey of the seven leading rheumatological journals published in 1987; 1107 original papers have been reviewed and classified according to study design, statistical techniques, and country of origin. Almost half of the published papers were clinical descriptive studies without inferential power; both authors and editors should reflect whether the impact of these studies on the knowledge of readers justifies their frequency. Analytical research was represented mainly by randomized clinical trials (15.6%), and case control studies (14.2%). Cohort studies represented 5.4% and this seems a low figure in a specialty in need of more aetiological research. Almost half of the papers originated from the USA or the UK; journals edited in these countries published papers mainly from the same country. English language journals from other countries published a larger percentage of papers from other countries, including many non-English speaking nations. Bibliometric studies are desirable to evaluate trends in publication.

Pleural effusion as manifestation of temporal arteritis.

Two patients with temporal arteritis who presented with pleural effusion are reported. Both had an exudate that responded to prednisolone treatment.