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 & Receptor. 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.

Auditory capacities in Middle Pleistocene humans from the Sierra de Atapuerca in Spain

Abstract: Human hearing differs from that of chimpanzees and most other anthropoids in maintaining a relatively high sensitivity from 2 kHz up to 4 kHz, a region that contains relevant acoustic information in spoken language. Knowledge of the auditory capacities in human fossil ancestors could greatly enhance the understanding of when this human pattern emerged during the course of our evolutionary history. Here we use a comprehensive physical model to analyze the influence of skeletal structures on the acoustic filtering of the outer and middle ears in five fossil human specimens from the Middle Pleistocene site of the Sima de los Huesos in the Sierra de Atapuerca of Spain. Our results show that the skeletal anatomy in these hominids is compatible with a human-like pattern of sound power transmission through the outer and middle ear at frequencies up to 5 kHz, suggesting that they already had auditory capacities similar to those of living humans in this frequency range.

Cerebrospinal fluid levels of transition metals in patients with Alzheimer's disease.

Abstract: We compared CSF and serum levels of iron, copper, manganese, and zinc, measured by atomic absorption spectrophotometry, in 26 patients patients with Alzheimer's disease (AD) without major clinical signs of undernutrition, and 28 matched controls. CSF zinc levels were significantly decreased in AD patients as compared with controls (p < 0.05). The serum levels of zinc, and the CSF and serum levels of iron, copper, and manganese, did not differ significantly between AD-patient and control groups. These values were not correlated with age, age at onset, duration of the disease, and scores of the MiniMental State Examination in the AD group. Weight and body mass index were significantly lower in AD patients than in controls. Because serum zinc levels were normal, the possibility that low CSF zinc levels were due to a deficiency of dietary intake seems unlikely. However, it is possible that they might be related to the interaction of beta-amyloid and/or amyloid precursor protein with zinc, that could result in a depletion of zinc levels.

letsR: a new R package for data handling and analysis in macroecology

Abstract: Summary 1. The current availability of large ecological data sets and the computational capacity to handle them have fostered the testing and development of theory at broad spatial and temporal scales. Macroecology has particularly benefited from this era of big data, but tools are still required to help transforming this data into information and knowledge. 2. Here, we present ‘letsR’, a package for the R statistical computing environment, designed to handle and analyse macroecological data such as species’ geographic distributions (polygons in shapefile format and point occurrences) and environmental variables (in raster format). The package also includes functions to obtain data on species’ habitat use, description year and current as well as temporal trends in conservation status as provided by the IUCN RedList online data base. 3. ‘letsR’ main functionalities are based on the presence–absence matrices that can be created with the package’s functions and from which other functions can be applied to generate, for example species richness rasters, geographic mid-points of species and species- and site-based attributes. 4. We exemplify the package’s functionality by describing and evaluating the geographic pattern of species’ description year in tailless amphibians. All data preparation and most analyses were made using the ‘letsR ’f unctions. Our example illustrates the package’s capability for conducting macroecological analyses under a single computer platform, potentially helping researchers to save time and effort in this endeavour.