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.

Prevalence of prostate cancer and prostatic intraepithelial neoplasia in Caucasian Mediterranean males: an autopsy study.

Abstract: Background The prevalence of carcinoma of the prostate gland (CaP) and high-grade prostatic intraepithelial neoplasia (HGPIN) was assessed in a Spanish population, representative of the Caucasian Mediterranean (CM) ethnic group Data were compared with those described in populations from other geographical regions and in other ethnic groups Methods CaP and HGPIN were evaluated in a consecutive series of prostatic glands collected at the post-mortem examination of 162 male patients born and living in Spain, aged 20–80 years, and dying from trauma The glands were sliced every 2–3 mm All slices were paraffin embedded and sectioned to obtain 5 μm whole-mount sections To compare the prevalence rate in our series and in other Caucasian populations with that from other geographical areas and other ethnic groups, we used data from the autopsy study performed at the Wayne State University Results Prevalence of CaP is 358, 882, 1428, 2380, 317, and 3333% in the 3rd, 4th, 5th, 6th, 7th, and 8th decades, respectively The rates of HGPIN were 714, 1175, 3571, 3806, 4540, and 4815% at the 3rd, 4th, 5th, and 8th decades of life Both CaP and HGPIN are located preferentially at the peripheral zone of the gland and in 21/27 cases (777%), an association between CaP and HGPIN was found The prevalence of both lesions in CM males is significantly lower than in Caucasian American (CA) and Afro-American (AA) males in all the age groups evaluated Conclusions Microscopic foci of CaP and HGPIN can be documented in CM males from the 3rd decade of life onwards The lesions become more frequent and extensive as age increases The prevalence of both lesions seems to be significantly lower in the CM population than in CA and AA males in all the age groups evaluated Prostate 54: 238–247, 2003 © 2002 Wiley-Liss, Inc

Student acceptance of virtual laboratory and practical work: An extension of the technology acceptance model

Abstract: The development of Internet technologies and new ways of sharing information has facilitated the emergence of a variety of elearning scenarios. However, in technological areas such as engineering, where students must carry out hands-on exercises and laboratory work essential for their learning, it is not so easy to design online environments for practicals. The aim of this experimental study was to examine students' acceptance of technology and the process of adopting an online learning environment incorporating web-based resources, such as virtual laboratories, interactive activities, and educational videos, and a game-based learning methodology. To this end, their responses to an online questionnaire (n = 223) were analyzed using structural equation modeling. The study was based on the technology acceptance model (TAM), but included and assessed other factors such as perceived efficiency, playfulness, and satisfaction, which are not explained by the TAM. Our results confirm that this extension of the TAM provides a useful theoretical model to help understand and explain users' acceptance of an online learning environment incorporating virtual laboratory and practical work. Our results also indicate that efficiency, playfulness, and students' degree of satisfaction are factors that positively influence the original TAM variables and students' acceptance of this technology. Here, we also discuss the significant theoretical and spractical implications for educational use of these web-based resources.

Increase in size and nitrogen concentration enhances seedling survival in Mediterranean plantations. Insights from an ecophysiological conceptual model of plant survival

Abstract: Reduction in size and tissue nutrient concentration is widely considered to increase seedling drought resistance in dry and oligotrophic plantation sites. However, much evidence indicates that increase in size and tissue nutrient concentration improves seedling survival in Mediterranean forest plantations. This suggests that the ecophysiological processes and functional attributes relevant for early seedling survival in Mediterranean climate must be reconsidered. We propose a ecophysiological conceptual model for seedling survival in Mediterranean-climate plantations to provide a physiological explanation of the frequent positive relationship between outplanting performance and seedling size and nutrient concentration. The model considers the physiological processes outlined in the plantation establishment model of Burdett (Can J For Res 20:415–427, 1990), but incorporates other physiological processes that drive seedling survival, such as N remobilization, carbohydrate storage and plant hydraulics. The model considers that seedling survival in Mediterranean climates is linked to high growth capacity during the wet season. The model is for container plants and is based on three main principles, (1) Mediterranean climates are not dry the entire year but usually have two seasons of contrasting water availability; (2) summer drought is the main cause of seedling mortality; in this context, deep and large roots is a key trait for avoiding lethal water stress; (3) attainment of large root systems in the dry season is promoted when seedlings have high growth during the wet season. High growth is achieved when seedlings can divert large amount of resources to support new root and shoot growth. Functional traits that confer high photosynthesis, nutrient remobilization capacity, and non-structural carbohydrate storage promote high growth. Increases in seedling size and nutrient concentration strongly affect these physiological processes. Traits that confer high drought resistance are of low value during the wet season because hinder growth capacity. We provide specific evidence to support the model and finally we discuss its implications and the factors that may alter the frequent increase in performance with increase in seedling size and tissue nutrient concentration.

Star formation relations and co spectral line energy distributions across the J-ladder and redshift

Abstract: We present FIR [50-300 mu m]-CO luminosity relations (i.e., log L-FIR = alpha log L'(CO) + beta) for the full CO rotational ladder from J = 1-0 up to J = 13-12 for a sample of 62 local (z 10(11) L-circle dot) using data from Herschel SPIRE-FTS and ground-based telescopes. We extend our sample to high redshifts (z > 1) by including 35 submillimeter selected dusty star forming galaxies from the literature with robust CO observations, and sufficiently well-sampled FIR/submillimeter spectral energy distributions (SEDs), so that accurate FIR luminosities can be determined. The addition of luminous starbursts at high redshifts enlarge the range of the FIR-CO luminosity relations toward the high-IR-luminosity end, while also significantly increasing the small amount of mid-J/high-J CO line data (J = 5-4 and higher) that was available prior to Herschel. This new data set (both in terms of IR luminosity and J-ladder) reveals linear FIR-CO luminosity relations (i.e., a similar or equal to 1) for J = 1-0 up to J = 5-4, with a nearly constant normalization (beta similar to 2). In the simplest physical scenario, this is expected from the (also) linear FIR-(molecular line) relations recently found for the dense gas tracer lines (HCN and CS), as long as the dense gas mass fraction does not vary strongly within our (merger/starburst)-dominated sample. However, from J = 6-5 and up to the J = 13-12 transition, we find an increasingly sublinear slope and higher normalization constant with increasing J. We argue that these are caused by a warm (similar to 100 K) and dense (>10(4) cm(-3)) gas component whose thermal state is unlikely to be maintained by star-formation-powered far-UV radiation fields (and thus is no longer directly tied to the star formation rate). We suggest that mechanical heating (e.g., supernova-driven turbulence and shocks), and not cosmic rays, is the more likely source of energy for this component. The global CO spectral line energy distributions, which remain highly excited from J = 6-5 up to J = 13-12, are found to be a generic feature of the (U)LIRGs in our sample, and further support the presence of this gas component.