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Showing papers by "University of Alcalá published in 2002"


Journal ArticleDOI
TL;DR: The analysis of some species-rich, well-defined food webs shows that they display the so-called small world behavior shared by a number of disparate complex systems, suggesting that communities might be self-organized in a non-random fashion that might have important consequences in their resistance to perturbations.

606 citations


Journal ArticleDOI
01 Dec 2002
TL;DR: An eye-control method based on electrooculography (EOG) to develop a system for assisted mobility where the control is actually effected by eye movements within the socket, which could be useful in multiple applications, such as mobility and communication aid for handicapped persons.
Abstract: Describes an eye-control method based on electrooculography (EOG) to develop a system for assisted mobility. One of its most important features is its modularity, making it adaptable to the particular needs of each user according to the type and degree of handicap involved. An eye model based on electrooculographic signal is proposed and its validity is studied. Several human-machine interfaces (HMI) based on EOG are commented, focusing our study on guiding and controlling a wheelchair for disabled people, where the control is actually effected by eye movements within the socket. Different techniques and guidance strategies are then shown with comments on the advantages and disadvantages of each one. The system consists of a standard electric wheelchair with an on-board computer, sensors and a graphic user interface run by the computer. On the other hand, this eye-control method can be applied to handle graphical interfaces, where the eye is used as a mouse computer. Results obtained show that this control technique could be useful in multiple applications, such as mobility and communication aid for handicapped persons.

452 citations


Journal ArticleDOI
TL;DR: This paper reviewed the Spanish experience of using temporary employment contracts for regular jobs since 1984, focusing on the role of fixed-term contracts with low severance pay, which have substituted for reform of employment protection legislation for permanent contracts.
Abstract: We review some lessons from the Spanish experience of using temporary employment contracts for regular jobs since 1984 The focus is on the role of fixed-term contracts with low severance pay, which have substituted for reform of employment protection legislation for permanent contracts We consider the main findings about this reform on the Spanish labour market in the light of the main theoretical implications derived from models dealing with dual labour markets, and address why the incidence of temporary work has remained highly persistent, around 33% of salaried employment, in the 1990s, despite several reforms aimed at reducing it

443 citations


Journal ArticleDOI
TL;DR: In patients with AVB, pharmacologic agents improve the efficacy of endoscopic therapy to achieve initial control of bleeding and 5‐day hemostasis, yet fail to affect mortality.

427 citations


Journal ArticleDOI
TL;DR: Current views of the relationship between competence and performance are described and some of the implications of the distinctions between the two areas are delineated for the purpose of assessing doctors in practice.
Abstract: Objective This paper aims to describe current views of the relationship between competence and performance and to delineate some of the implications of the distinctions between the two areas for the purpose of assessing doctors in practice. Methods During a 2-day closed session, the authors, using their wide experiences in this domain, defined the problem and the context, discussed the content and set up a new model. This was developed further by e-mail correspondence over a 6-month period. Results Competency-based assessments were defined as measures of what doctors do in testing situations, while performance-based assessments were defined as measures of what doctors do in practice. The distinction between competency-based and performance-based methods leads to a three-stage model for assessing doctors in practice. The first component of the model proposed is a screening test that would identify doctors at risk. Practitioners who ‘pass’ the screen would move on to a continuous quality improvement process aimed at raising the general level of performance. Practitioners deemed to be at risk would undergo a more detailed assessment process focused on rigorous testing, with poor performers targeted for remediation or removal from practice. Conclusion We propose a new model, designated the Cambridge Model, which extends and refines Miller's pyramid. It inverts his pyramid, focuses exclusively on the top two tiers, and identifies performance as a product of competence, the influences of the individual (e.g. health, relationships), and the influences of the system (e.g. facilities, practice time). The model provides a basis for understanding and designing assessments of practice performance.

390 citations


Journal ArticleDOI
TL;DR: In this article, a new spectral index named Burned Area Index (BAI) was designed for burned land discrimination in the red-near-infrared spectral domain, which was tested on multitemporal sets of Landsat Thematic Mapper and NOAA Advanced Very High Resolution Radiometer (AVHRR) images.
Abstract: A new spectral index named Burned Area Index (BAI), specifically designed for burned land discrimination in the red-near-infrared spectral domain, was tested on multitemporal sets of Landsat Thematic Mapper (TM) and NOAA Advanced Very High Resolution Radiometer (AVHRR) images. The utility of BAI for burned land discrimination was assessed against other widely used spectral vegetation indices: Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI) and Global Environmental Monitoring Index (GEMI). BAI provided the highest discrimination ability among the indices tested. It also showed a high variability within scorched areas, which reduced the average normalized distances with respect to other indices. A source of potential confusion between burned land areas and low-reflectance targets, such as water bodies and cloud shadows, was identified. Since BAI was designed to emphasize the charcoal signal in post-fire images, this index was highly dependent on the temporal permanence o...

336 citations


Journal ArticleDOI
TL;DR: The changes in the distribution of this critical enzyme suggests that the glutamate-glutamine cycle may be differentially impaired in hyperammonemic states.

323 citations


Journal ArticleDOI
TL;DR: In this paper, the technical feasibility and performance of photocatalytic degradation of four water-soluble pesticides (diuron, imidacloprid, formetanate and methomyl) have been studied at pilot scale in two well-defined systems of special interest because natural-solar UV light can be used: heterogeneous photocatalysis with titanium dioxide and homogeneous photocATalysis by photo-Fenton.

312 citations


Journal ArticleDOI
TL;DR: There is an essential role for Nav1.8 in mediating spontaneous activity in sensitized nociceptors in the absence of additional stimuli, according to a visceral model of tonic noxious chemical stimulation, cyclophosphamide cystitis.
Abstract: The tetrodotoxin-resistant sodium channel α subunit Nav1.8 is expressed exclusively in primary sensory neurons and is proposed to play an important role in sensitization of nociceptors. Here we compared visceral pain and referred hyperalgesia in Nav1.8-null mice and their wild-type littermates in five tests that differ in the degree to which behavior depends on spontaneous, ongoing firing in sensitized nociceptors. Nav1.8-null mice showed normal nociceptive behavior provoked by acute noxious stimulation of abdominal viscera (intracolonic saline or intraperitoneal acetylcholine). However, Nav1.8-null mutants showed weak pain and no referred hyperalgesia to intracolonic capsaicin, a model in which behavior is sustained by ongoing activity in nociceptors sensitized by the initial application. Nav1.8-null mice also showed blunted pain and hyperalgesia to intracolonic mustard oil, which sensitizes nociceptors but also provokes tissue damage. To distinguish between a possible role for Nav1.8 in ongoing activity per se and ongoing activity after sensitization in the absence of additional stimuli, we tried a visceral model of tonic noxious chemical stimulation, cyclophosphamide cystitis. Cyclophosphamide produces cystitis by gradual accumulation of toxic metabolites in the bladder. In this model, Nav1.8-null mice showed normal responses. There were no differences between null mutants and their normal littermates in tissue damage and inflammation evoked by any of the stimuli tested, suggesting that the behavioral differences are not secondary to impairment of inflammatory responses. We conclude that there is an essential role for Nav1.8 in mediating spontaneous activity in sensitized nociceptors.

255 citations


Journal ArticleDOI
TL;DR: A review is presented dealing with electrocatalytic NADH oxidation at mediator-modified electrodes, summarising the history of the topic, as well as the present state of the art.

236 citations


Journal ArticleDOI
TL;DR: An eye-control method, based on electrooculography (EOG), for guiding and controlling a wheelchair for disabled people; the control is actually effected by eye movements within the socket.
Abstract: This paper describes an eye-control method, based on electrooculography (EOG), for guiding and controlling a wheelchair for disabled people; the control is actually effected by eye movements within the socket. An eye model based on an electrooculographic signal is proposed and its validity is studied. Different techniques and guidance strategies are then shown with comments on the advantages and disadvantages of each one. The system consists of a standard electric wheelchair with an on-board computer, sensors and a graphic user interface run by the computer. This control technique could be useful in multiple applications, such as mobility and communication aid for handicapped persons.

Journal ArticleDOI
TL;DR: Here different characteristic features of complex nets, as well as their behavior under different sources of perturbation, are considered.
Abstract: Summary of the Basic Features that Relate and Distinguish Different Types of Complex Networks, Both Natural and Artificial Property Proteomics Ecology Language TechnologyTinkering Gene duplication and recruitation Local assemblages fromregional species pools andpriority effectsCreation of words fromalready established onesReutilization of modules andcomponentsHubs Cellular signaling genes (e.g.,p53)Omnivorous and mostabundant speciesFunction words Most used componentsWhat can be optimized? Communication speed and linkingcostUnclear Communication speed withrestrictionsMinimize development effortwithin constraintsFailures Small phenotypic effect ofrandom mutationsLoss of only a few species-specific functionsMaintenance of expressionand communicationLoss of functionalityAttacks Large alterations of cell-cycle andapoptosis (e.g., cancer)Many coextinctions and lossof several ecosystemsfunctionsAgrammatism (i.e., greatdifficulties for buildingcomplex sentences)Avalanches of changes and largedevelopment costsRedundancy and degeneracy Redundant genes rapidly lost R minimized and D restrictedto non-keystone speciesGreat D Certain degree of R but no DHere different characteristic features of complex nets, as well as their behavior under different sources of perturbation, are considered.

Journal ArticleDOI
TL;DR: C carvedilol has a greater portal hypotensive effect than propranolol in patients with cirrhosis, however, its clinical applicability may be limited by its systemic hypotensive effects.

Posted Content
TL;DR: In this paper, the effects of reduced payroll taxes and dismissal costs on the distribution of employment and worker flows were investigated using individual data from the Spanish Labor Force Survey, showing that the reduction of payroll taxes increased the employment of young workers on permanent contracts.
Abstract: Temporary employment contracts allowing unrestricted dismissals were introduced in Spain in 1984 and quickly came to account for most new jobs. As a result, temporary employment increased from around 10% in the mid-eighties to more than 30% in the early nineties. In 1997, however, the Spanish government attempted to reduce the incidence of temporary employment by reducing payroll taxes and dismissal costs for permanent contracts. In this paper, we use individual data from the Spanish Labor Force Survey to estimate the effects of reduced payroll taxes and dismissal costs on the distribution of employment and worker flows. We exploit the fact that recent reforms apply only to certain demographic groups to set up a natural experiment research design that can be used to study the effects of contract regulations. Our results show that the reduction of payroll taxes and dismissal costs increased the employment of young workers on permanent contracts. Results for older workers show insignificant effects. The results suggest a reasonably elastic response of permanent employment to nonwage labor costs for young workers. We also find positive effects on the transitions from unemployment and temporary employment into permanent employment for young and older workers, although the effects for older workers are not always significant. On the other hand, transitions from permanent employment to nonemployment increased only for older men, suggesting that the reform had little effect on dismissals.

Journal ArticleDOI
TL;DR: The concentrations of aluminium (Al), arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), manganese (Mn), nickel (Ni), lead (Pb), tin (Sn), thallium (Tl), vanadium (V), and zinc (Zn) were determined in soil samples collected in Alcala de Henares (Madrid, Spain) as discussed by the authors.

Journal ArticleDOI
TL;DR: In this article, the role of externalities in promoting industrial growth in Spanish regions is discussed, and the analysis is restricted to dynamic externalities using productivity, instead of labor, using data from the Spanish Industry Survey from 1978 to 1992 for 26 manufacturing branches.

Journal ArticleDOI
TL;DR: In this paper, spectral mixture analysis (SMA) was used to understand regeneration patterns after fire in two semiarid shrub communities of the Santa Monica Mountains, California: northern mixed chaparral and coastal sage scrub.

Journal ArticleDOI
TL;DR: Two Landsat images, acquired in 1982 and 1992 were used to evaluate the potential of using remote sensing analysis in desertification monitoring, and simple differences between unmixed images of sand or water revealed dune movement, re-vegetation trends and variations in water bodies, as a result of changing rainfall and land use patterns.

Journal ArticleDOI
TL;DR: A single-channel chip-based analytical microsystem that allows rapid flow injection measurements of the total content of organic explosive or nerve agent compounds, as well as detailed micellar chromatographic identification of the individual ones, is described, which will lead to the creation of a field-deployable microanalyzer and will enable transporting the forensic laboratory to the sample source.
Abstract: A single-channel chip-based analytical microsystem that allows rapid flow injection measurements of the total content of organic explosive or nerve agent compounds, as well as detailed micellar chromatographic identification of the individual ones, is described. The protocol involves repetitive rapid flow injection (screening) assaysto provide a timely warning and alarmand switching to the separation (fingerprint identification) mode only when harmful compounds are detected. While micellar electrokinetic chromatography, in the presence of sodium dodecyl sulfate (SDS), is used for separating the neutral nitroaromatic explosive and nerve agent compounds, an operation without SDS leads to high-speed measurements of the “total” explosives or nerve agent content. Switching between the “flow injection” and “separation” modes is accomplished by rapidly exchanging the SDS-free and SDS-containing buffers in the separation channel. Amperometric detection was used for monitoring the separation. Key factors influenci...

Journal ArticleDOI
TL;DR: Evidence that a genetic component is involved in controlling age- and size-related changes in foliar morphology and physiology is reviewed and the possibility of complex interactions among model pathways is discussed.
Abstract: Woody plants exhibit significant and predictable patterns of change in morphology and physiology as they become older and larger. Four models of potential pathways controlling these changes are presented: a stimulus-response model in which fully developed organs respond to changes in environment (defined here as everything external to the organ); an extrinsic model in which the attributes of developing organs are determined by environmental factors; an intrinsic model in which changes are a result of programmed changes in gene expression; and an extrinsic-intrinsic model in which changes in gene expression are induced by environmental factors. We review evidence that a genetic component is involved in controlling age- and size-related changes in foliar morphology and physiology and discuss the possibility of complex interactions among model pathways.

Journal ArticleDOI
01 Jul 2002-Oikos
TL;DR: The results suggest that the ecological role of Opuntia clumps as refuge from cattle grazing should be taken into consideration in management practices aimed at cactus eradication in order to increase forage availability for livestock.
Abstract: This study evaluates the hypothesis that biological grazing refuges have an important role in plant-grazer interactions of grasslands with a long history of grazing. We assessed the hypothesis that clumps of the spiny cactus Opuntia polyacantha provide biological refuges from cattle grazing, affecting cover and seedhead production of associated vascular plants in the shortgrass steppe of the North America. The study was based on sampling inside and outside Opuntia clumps in eight long-term moderately grazed pastures established 60 yr ago and their respective ungrazed controls. Opuntia clumps provided a refuge for seedhead production of the dominant grass (Bouteloua gracilis) and for cover and seedhead production of many plant groups. Clumps were also a refuge for species sensitive to grazing (species that decrease with grazing) and barrel-cacti, but not for species preferred by cattle (species with greater proportion in the diet than in the field), exotics or weeds. Our results suggest that these effects were mainly through changes in the microenvironmental conditions resulting from protection effects, even though all potential microenvironmental effects could not be measured. Cacti promoted some negative effects on other plant groups, probably due to the space occupied by cladodes inside cactus clumps. The refuge effects observed at the group level did not translate into strong community level effects. Species diversity (H′) was greater in cactus clumps due to lower dominance rather than greater richness. The presence of Opuntia clumps increased landscape-scale diversity. This ecological role of Opuntia clumps as refuge from cattle grazing should be taken into consideration in management practices aimed at cactus eradication in order to increase forage availability for livestock. We discuss the potential role of plant community productivity and grazing history with regard to the importance of natural refuges in structuring grassland communities.

Journal ArticleDOI
TL;DR: In this article, a new model for the topology of magnetic clouds at 1 AU that relates the magnetic field vector with the current density of the cloud without assuming the force-free condition is presented.
Abstract: [1] We present a new model for the topology of magnetic clouds at 1 AU that relates the magnetic field vector with the current density of the cloud without assuming the force-free condition. In addition, the model is formulated in such a way that it can be fitted directly to the data without the need of initially determining the flux rope axis by minimum variance. The model provides both the magnetic field strength and the direction in just one fitting procedure. In addition to the orientation of its axis and the relative closest-approach distance between the spacecraft and the cloud axis, the fit of the model to the experimental data allows an estimation of the current density of plasma inside the magnetic cloud. From our study on several clouds we conclude that this has values of the order of 10−12 C m−2 s−1. Compared with the force-free model, although the improvement gained in the χ2 values is not very great, the fitting procedure is shorter and easier, and the number of parameters involved has been reduced from seven to five. Our model also lets us check the validity of force-free approximation by the calculation of the value of the current density perpendicular to the flux rope, j⟂ = j × B/|B|. This component is assumed to be zero in the force-free model, but for all analyzed cases we obtain a nonzero value. This finite value implies the existence of pressure gradients inside the cloud that cannot be explained with a force-free approximation. In this paper, four cases are presented that have already been analyzed in the literature. We show that our model can explain the profiles of the magnetic field as a magnetic cloud passes a spacecraft.

Journal ArticleDOI
TL;DR: In maize, cells at the base of the endosperm are transformed into transfer cells that facilitate nutrient uptake by the developing seed and ZmMRP-1 is the first transfer cell–specific transcriptional activator to be identified.
Abstract: In maize, cells at the base of the endosperm are transformed into transfer cells that facilitate nutrient uptake by the developing seed. ZmMRP-1 is the first transfer cell-specific transcriptional activator to be identified. The protein it encodes contains nuclear localization signals and a MYB-related DNA binding domain. A single gene copy is present in maize, mapping to a locus on chromosome 8. ZmMRP-1 is first expressed soon after fertilization, when the endosperm is still a multinuclear coenocyte. The transcript accumulates in the basal nucleocytoplasmic domain that gives rise to transfer cells after cellularization. The transcript can be detected throughout transfer cell development, but it is not found in mature cells. ZmMRP-1 strongly transactivates the promoters of two unrelated transfer cell-specific genes. The properties of ZmMRP-1 are consistent with it being a determinant of transfer cell-specific expression. Possible roles for ZmMRP-1 in the regulation of endosperm and transfer cell differentiation are discussed.

Journal ArticleDOI
TL;DR: In this article, a growing pied flycatchers (Ficedula hypoleuca) was assessed from cell counts in blood smears and levels of two heat-shock protein (HSPs, HSP60 and HSP70) from the cell fraction of peripheral blood.
Abstract: Growing altricial birds may experience nutritional stress in the nest due to sibling competition, food restriction, or parasites. Nutritional stress may be detected through its effect on nestling growth, although genetic and maternal effects may interfere with its expression. A more direct way of estimating nutritional stress may be through measurements of organismic stress in growing birds. Heterophil/lymphocyte ratios (H/L) have been proposed as reliable physiological indicators of the stress response. Heat-shock protein (HSP) synthesis is induced by animals in response to various stressors, making the concentration of HSPs a suitable measure of organismic stress. In a study of growing pied flycatchers (Ficedula hypoleuca), we assessed H/L from cell counts in blood smears and levels of two HSPs, HSP60 and HSP70, from the cell fraction of peripheral blood. H/L and the level of HSP60 were significantly positively associated in nestlings of 13 days of age, while the level of HSP70 was not related t...

Journal ArticleDOI
TL;DR: In this article, the authors present an extension of a previous model for the topology of magnetic clouds which takes into account their interaction with the solar wind, and the main consequence of this interaction is the possible distortion of their cross-section, that need no longer be circular during the propagation from the Sun to 1AU.
Abstract: [1] In this work we present an extension of a previous model for the topology of magnetic clouds which takes into account their interaction with the solar wind. The main consequence of this interaction is the possible distortion of their cross-section, that need no longer be circular during the propagation from the Sun to 1AU. The first approach to this deformation is to assume an elliptical geometry for the cross section although we consider a cylindrical shape for the clouds. Once we make the assumptions of an uniform radial component of the plasma current density and a null value for the radial component of the magnetic field vector, the solutions of the Maxwell equations and the continuity equation in stationary conditions, both expressed in elliptical coordinates, incorporate the expansion of the cross-section of the cloud. To illustrate the model we present the fitting of four selected clouds with different magnetic field profiles. We show in all cases analyzed that the fits are indeed good and have eight free parameters.

Journal ArticleDOI
TL;DR: A simple evolutionary model with three trophic levels is presented, and its properties are compared with characteristic patterns of ecological response to disturbances in continuous models of three-level ecosystems to provide a preliminary ecological theory of recoveries.
Abstract: Biotic recoveries following mass extinctions are characterized by a process in which whole ecologies are reconstructed from low-diversity systems, often characterized by opportunistic groups. The recovery process provides an unexpected window to ecosystem dynamics. In many aspects, recovery is very similar to ecological succession, but important differences are also apparently linked to the innovative patterns of niche construction observed in the fossil record. In this paper, we analyse the similarities and differences between ecological succession and evolutionary recovery to provide a preliminary ecological theory of recoveries. A simple evolutionary model with three trophic levels is presented, and its properties (closely resembling those observed in the fossil record) are compared with characteristic patterns of ecological response to disturbances in continuous models of three-level ecosystems.

Journal ArticleDOI
TL;DR: Phylogenetic analyses indicated a close genetic relationship between Tirmania and Terfezia, and the re-establishment of the genus Mattirolomyces was supported.
Abstract: Terfezia and Tirmania, so called desert truffles, are mycorrhizal fungi mostly endemic to arid and semi-arid areas of the Mediterranean Region, where they are associated with Helianthemum species. The aim of this work was to study the phylogenetic relationships in these pezizalean hypogeous fungi. The restriction fragment length polymorphism (RFLP) and DNA sequences of internal transcribed spacers (ITS) of the nuclear rDNA were studied for several morphological species, Terfezia arenaria, T. boudieri, T. claveryi, T. leptoderma, T. terfezioides (=Mattirolomyces terfezioides), Tirmania nivea and T. pinoyi. The sequences were analyzed with distance and parsimony methods. Phylogenetic analyses indicated a close genetic relationship between Tirmania and Terfezia. They may have arisen from a single evolutionary lineage of pezizalean fungi that developed the hypogeous habit as an adaptation to heat and drought in Mediterranean ecosystems. This analysis also supports the re-establishment of the genus Mattirolomyces. The genera Tirmania and Terfezia were monophyletic, and morphological species corresponded to phylogenetic species. The Tirmania clade comprises desert truffles with smooth spores and amyloid asci, which were found in deserts. The Terfezia clade grouped species found in semi-arid habitats having ornamented and spherical spores. These species are adapted to exploit different types of soil (either acid or basic soils) in association with specific hosts (either basophilous or acidophilous species). Although other factors might also play a role, host specialization and edaphic tolerances (fungus and/or host tolerances) might be the key in the species diversity of these genera.

Journal ArticleDOI
TL;DR: Because of the severe consequences an assessment of practice performance may have, it is essential that the procedure is both defensible to the stakeholders and fair in that it distinguishes well between good performers and underperformers.
Abstract: Introduction An essential element of practice performance assessment involves combining the results of various procedures in order to see the whole picture. This must be derived from both objective and subjective assessment, as well as a combination of quantitative and qualitative assessment procedures. Because of the severe consequences an assessment of practice performance may have, it is essential that the procedure is both defensible to the stakeholders and fair in that it distinguishes well between good performers and underperformers. Lessons from competence assessment Large samples of behaviour are always necessary because of the domain specificity of competence and performance. The test content is considerably more important in determining which competency is being measured than the test format, and it is important to recognise that the process of problem-solving process is more idiosyncratic than its outcome. It is advisable to add some structure to the assessment but to refrain from over-structuring, as this tends to trivialise the measurement. Implications for practice performance assessment A practice performance assessment should use multiple instruments. The reproducibility of subjective parts should not be increased by over-structuring, but by sampling through sources of bias. As many sources of bias may exist, sampling through all of them may not prove feasible. Therefore, a more project-orientated approach is suggested using a range of instruments. At various timepoints during any assessment with a particular instrument, questions should be raised as to whether the sampling is sufficient with respect to the quantity and quality of the observations, and whether the totality of assessments across instruments is sufficient to see ‘the whole picture’. This policy is embedded within a larger organisational and health care context.

Journal ArticleDOI
TL;DR: The aims of this study were to estimate the prevalence of major maturity-onset diabetes of the young (MODY) subtypes in Spanish MODY families and to analyze genotype-phenotype correlations.
Abstract: The aims of this study were to estimate the prevalence of major maturity-onset diabetes of the young (MODY) subtypes in Spanish MODY families and to analyze genotype-phenotype correlations. Twenty-two unrelated pediatric MODY patients and 97 relatives were screened for mutations in the coding region of the glucokinase (GCK), hepatic nuclear factor- HNF-1alpha and HNF4alpha genes using PCR-single strand conformation polymorphism and/or direct sequencing. In families carrying GCK mutations, the influence of genetic defects on fetal growth was investigated by comparing the birth weights of 32 offspring discordant for the mutations. Mutations in MODY genes were identified in 64% of the families. GCK/MODY2 mutations were the most frequently found, in 41%: seven novel (R369P, S411F, M298K, C252Y, Y108C, A188E, and S383L) and 2 already described mutations. Four pedigrees (18%) harbored mutations in the HNF-1alpha/MODY3 gene, including a previously unreported change (R271G). One family (4%) carried a novel mutation in the HNF-4alpha gene (IVS5-2delA), representing the first report of a MODY1 pedigree in the Spanish population. The age at diagnosis was prepubertal in MODY2 index patients and pubertal in MODY3 patients. Overt diabetes was rare in MODY2 and was invariably present in MODY3 index patients. Chronic complications of diabetes were absent in the MODY2 population and were present in more than 40% of all relatives of MODY3. Birth weight was lower in the presence of a GCK fetal mutation when the mutation was of paternal origin. The MODY1 patient was diagnosed at 15 yr of age. She developed intermittent microalbuminuria despite good metabolic control, and severe late-onset complications were common within her family. Mutations in the GCK/MODY2 gene are the most common cause of MODY in our population as recruited from pediatric and adolescent index patients. The inheritance of GCK defects by the fetus results in a reduction of birth weight. Clinical expression of MODY3 and MODY1 mutations, the second and third groups of defects found, was more severe, including the frequent development of chronic complications.

Journal ArticleDOI
TL;DR: In this article, the authors associated patterns of plant diversity with posible causal factors by considering 93 local regions in the Iberian Peninsula and Balearic Islands with respect to biogeo-graphy, environmental favourability, and environmental hetero- geneity, and their relationship with measured species diversity at four different scales: mean local species richness, total species richness in a community type within a region (regional community richness), mean compositional similarity, and mosaic diversity.
Abstract: We associated patterns of plant diversity with pos- sible causal factors by considering 93 local regions in the Iberian Peninsula and Balearic Islands with respect to biogeo- graphy, environmental favourability, and environmental hetero- geneity, and their relationship with measured species diversity at four different scales: mean local species richness standard- ized at a grain of 100 m2, total species richness in a community type within a region (regional community richness), mean compositional similarity, and mosaic diversity. Local regions in biogeographic transition zones to the North African and Atlantic floras had higher regional commu- nity richness and greater mosaic diversity than did non-transi- tional regions, whereas no differences existed in mean local species richness or mean compositional similarity. Mean local species richness was positively related to environmental fa- vourability as measured by actual evapotranspiration, but negatively related to total precipitation and temporal heteroge- neity in precipitation. Mean local species richness was great- est in annual grassland and dwarf shrubland communities, and on calcareous bedrock types. Regional community richness was similarly related to actual evapotranspiration and total precipitation, but in addition was positively related to spatial heterogeneity in topography and soil water holding capacity. Mean compositional similarity decreased with increasing spa- tial heterogeneity and temperature seasonality. Mosaic diver- sity, a measure of complexity, increased with increasing local and regional richness. We hypothesize that these relationships can be explained by four ecological and evolutionary classes of causal factors: numbers of individuals, intermediate environments, limits to adaptation, and niche variation. These factors operate at various scales and manifest themselves in various ways. For example, at the site level, apparently processes that increase the number of individuals increase mean local species richness, but at the level of the entire region no such effects were found.