University of Alcalá

About: University of Alcalá is a education organization based out in Alcalá de Henares, Spain. It is known for research contribution in the topics: Population & Context (language use). The organization has 10795 authors who have published 20718 publications receiving 410089 citations. The organization is also known as: University of Alcala & University of Alcala de Henares.

Measurement of the proton-air cross section at √s=57 TeV with the Pierre Auger Observatory.

Abstract: We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505 +/- 22(stat)(-36)(+28)(syst)] mb is found.

Increasing the Hematocrit Has a Beneficial Effect on Quality of Life and Is Safe in Selected Hemodialysis Patients

Abstract: Target hematocrit/hemoglobin values in dialysis patients are still controversial. The Spanish Cooperative Renal Patients Quality of Life Study Group (including 34 hemodialysis units) conducted a prospective, 6-mo study of the effect on patient functional status and quality of life of using epoetin to achieve normal hematocrit in hemodialysis patients with anemia. The possible adverse effects of increased hematocrit, patient hospitalization, and epoetin requirements were also studied. The study included 156 patients (age range, 18 to 65 yr). Given the minimal experience in the safety of increasing hematocrit in dialysis patients to normal levels with epoetin, stable patients on hemodialysis who had received epoetin treatment for at least 3 mo and had a stable hemoglobin level of > or = 9 g/dl were included in the study. Patients with antecedents of congestive cardiac failure, ischemic cardiopathy, diabetes mellitus, uncontrolled hypertension, cerebrovascular accident or seizures, malfunction of the vascular access or severe comorbidity (defined by a comorbidity index), and those over 65 yr of age were excluded from the study. Quality of life was measured with the Sickness Impact Profile (SIP) and Karnofsky scale. Patients completed questionnaires at home at onset and conclusion of the 6-mo study. Mean hematocrit increased from 30.9 to 38.4% and hemoglobin from 10.2 to 12.5 g/dl during the study. Health indicator scores improved significantly: mean Physical Dimension (SIP) from 5.38 to 4.1 (P < 0.005); mean Psychosocial Dimension from 9.2 to 7 (P < 0.001); mean global SIP from 8.9 to 7.25 (P < 0.001); mean Karnofsky scale score from 75.6 to 78.4 (P < 0.01). (SIP is scaled so that lower scores represent better functional status, and vice versa for the Karnofsky scale). Therefore, functional status and quality of life improved with increased hematocrit. No deaths occurred. Three patients (2%) were censored for hypertension and nine (5.7%) for thrombosis of the vascular access. The cumulative probability of thrombosis of the vascular access was 0.067. The average epoetin dose rose from 93 +/- 62 U/kg per wk at onset to 141 +/- 80 U/kg per wk at conclusion, a 51% increase. The number of patients hospitalized decreased and hospital lengths of stay were shorter during the study period than in the same patients in the 6-mo period preceding the study (P < 0.05). Nine patients (5.7%) had thrombosis of the vascular access. There were no changes in the prevalence of arterial hypertension, but three patients (2%) showed hypertension that was difficult to control. It is concluded that normalization of hematocrit in selected hemodialysis patients, i.e., nondiabetic patients without severe cardiovascular or cerebrovascular comorbidities, improves quality of life and decreases morbidity without significant adverse effects.

Climate change and fitness components of a migratory bird breeding in the Mediterranean region

Abstract: The increase in spring temperatures in temperate regions over the last two decades has led to an advancing spring phenology, and most resident birds have responded to it by advancing their onset of breeding. The pied flycatcher (Ficedula hypoleuca) is a long-distance migrant bird with a relatively late onset of breeding with respect to both resident birds and spring phenology in Europe. In the present correlational study, we show that some fitness components of pied flycatchers are suffering from climate change in two of the southernmost European breeding populations. In both montane study areas, temperature during May increased between 1980 and 2000 and an advancement of oak leafing was detected by using the normalized difference vegetation index (NDVI) to assess tree phenology. This might result in an advancement of the peak in availability of caterpillars, the main prey during the nestling stage. Over the past 18 yr, the time of egg laying and clutch size of pied flycatchers were not affected by the increase in spring temperatures in these Mediterranean populations. However, this increase seems to have an adverse effect on the reproductive output of pied flycatchers over the same period. Our data suggest that the mismatch between the timing of peak food supply and nestling demand caused by recent climate change might result in a reduction of parental energy expenditure that is reflected in a reduction of nestling growth and survival of fledged young in our study populations. The data seem to indicate that the breeding season has not shifted and it is the environment that has shifted away from the timing of the pied flycatcher breeding season. Mediterranean pied flycatchers were not able to advance their onset of breeding, probably, because they are constrained by their late arrival date and their restricted high altitude breeding habitat selection near the southern border of their range.

Depth of maximum of air-shower profiles at the Pierre Auger Observatory. II. Composition implications

Abstract: Using the data taken at the Pierre Auger Observatory between December 2004 and December 2012, we have examined the implications of the distributions of depths of atmospheric shower maximum (X-max), using a hybrid technique, for composition and hadronic interaction models. We do this by fitting the distributions with predictions from a variety of hadronic interaction models for variations in the composition of the primary cosmic rays and examining the quality of the fit. Regardless of what interaction model is assumed, we find that our data are not well described by a mix of protons and iron nuclei over most of the energy range. Acceptable fits can be obtained when intermediate masses are included, and when this is done consistent results for the proton and iron-nuclei contributions can be found using the available models. We observe a strong energy dependence of the resulting proton fractions, and find no support from any of the models for a significant contribution from iron nuclei. However, we also observe a significant disagreement between the models with respect to the relative contributions of the intermediate components.

Stem Cell Membrane-Coated Nanogels for Highly Efficient In Vivo Tumor Targeted Drug Delivery

Abstract: Stem cell membrane-coated nanogels can effectively evade clearance of the immune system, enhance the tumor targeting properties and antitumor chemotherapy efficacy of gelatin nanogels loaded doxorubicin in mice.