Creixement de rebrots d'alzina en una brolla postincendi en el període entre tres y sis anys després de fertilitzar-los

La disponibilitat de nutrients pot limitar la velocitat de recreixement de la vegetació després del foc, sobretot en llocs reiteradament cremats. Fruit d'un experiment de fertilització i reg, en aquest treball es valora el creixement en diimetre basal, secció basal i alçada de rebrots d'alzina (Quercus ilex ssp. ballota) en una brolla calcícola postincendi al Bages, durant el període entre tres i sis anys després de fertilitzar-10s. El 1990, cinc anys després del darrer incendi, es van tractar 78 individus en un disseny factorial amb 3 factors a 2 nivells cadascun: fertilització amb nitrogen (O i 500 kg N/ha en aplicació única), fertilització amb fbsfor (O i 250 kg P/ha en aplicació Única) i reg (O i 24 mm setmanals entre els mesos d'abril i agost dels anys 1991, 1992 i 1993). Entre els tres i els sis anys després de la fertilització, el creixement s'ha vist beneficiat significativament pel fbsfor en solitari (14% 13 anys d'increment relatiu mitjl de diimetre basal en les alzines fertilitzades amb només fòsfor respecte a un 6% 13 anys en les alzines control) i per l'acció sinkrgica de nitrogen i fòsfor (33% 13 anys d'increment relatiu de dilmetre basal en les alzines fertilitzades amb tots dos nutrients). El reg previ i el nitrogen en solitari no van tenir efectes significatius sobre el creixement. Aquests resultats demostren que els efectes positius de la fertilització amb P perduren no només els tres primers anys després de fertilitzar, com ja va trobar Sardans (1997), sinó que persisteixen com a m'nim sis anys.Regrowth of vegetation after a fire can be limited by nutrient availability, particularly after repeated bums. Using a previous field experiment of fertilization and irrigation in a bumt calcareous shrubland, we report growth rates in basal diarneter, basal cross sectional area, and height for holm oak (Quercus ilex ssp. ballota) resprouts during the period between 3 and 6 years after fertilization. In 1990, five years after the last burn, 78 holm oak genets were used in a factorial design involving three factors, each at two levels: nitrogen fertilization (O and 500 kg N/ha in a single application), phosphorus fertilization (O and 250 kg Plha in a single application), and irrigation (O and 24 mrn per week from April to August in 1991, 1992 and 1993). Between 3 and 6 years after fertilizing, growth was significantly enhanced by P (mean relative growth rate in basal diarneter of 14% I 3 years in holm oaks fertilized with only P, compared to 6% 13 years in control individuals). There was a positive interaction between N and P, the mean relative growth rate in basal diameter reaching 33% 1 3 years in holm oaks which had received N+P. Previous irrigation and N-only fertilization had no significant effects on growth. These results demonstrate that the positive effects of P fertilization on holm oak regrowth extend not only for the first 3 years after fertilizing as shown by Sardans (1997) but persist at least for 6 years

Quadrature and polarization squeezing in a dispersive optical bistability model

We theoretically study quadrature and polarization squeezing in dispersive optical bistability through a vectorial Kerr cavity model describing a nonlinear cavity filled with an isotropic chi(3) medium in which self-phase and cross-phase modulation, as well as four--wave mixing, occur. We derive expressions for the quantum fluctuations of the output field quadratures as a function of which we express the spectrum of fluctuations of the output field Stokes parameters. We pay particular attention to study how the bifurcations affecting the non-null linearly polarized output mode squeezes the orthogonally polarized vacuum mode, and show how this produces polarization squeezing.Comment: 10 text pages + 12 figure

Some conceptual difficulties regarding "net" multipliers

Multipliers are routinely used for impact evaluation of private projects and public policies at the national and subnational levels. Oosterhaven and Stelder (2002) correctly pointed out the misuse of standard 'gross' multipliers and proposed the concept of 'net' multiplier as a solution to this bad practice. We prove their proposal is not well founded. We do so by showing that supporting theorems are faulty in enunciation and demonstration. The proofs are flawed due to an analytical error but the theorems themselves cannot be salvaged as generic, non-curiosum counterexamples demonstrate. We also provide a general analytical framework for multipliers and, using it, we show that standard 'gross' multipliers are all that is needed within the interindustry model since they follow the causal logic of the economic model, are well defined and independent of exogenous shocks, and are interpretable as predictors for change

Allergen sensitization stratifies IL-31 production by memory T cells in atopic dermatitis patients

Background:The role of allergen sensitization in IL-31 production by T cells and specifically in the clinical context of atopic dermatitis (AD) has not been characterized. MethodsThe response to house dust mite (HDM) in purified memory T cells cocultured with epidermal cells from AD patients (n=58) and control subjects (n=11) was evaluated. AD-associated cytokines from culture supernatants, plasma proteins and mRNA expression from cutaneous lesions were assessed and related with the clinical features of the patients. ResultsHDM-induced IL-31 production by memory T cells defined two subsets of AD patients according to the presence or absence of IL-31 response. Patients in the IL-31 producing group showed a more inflammatory profile, and increased HDM-specific (sp) and total IgE levels compared to the IL-31 non-producing group. A correlation between IL-31 production and patient's pruritus intensity, plasma CCL27 and periostin was detected. When the same patients were analyzed based on sp IgE and total IgE levels, an increased IL-31 in vitro response, as well as type 2 markers in plasma and cutaneous lesions, was found in patients with sp IgE levels > 100 kUA/L and total IgE levels > 1000 kU/L. The IL-31 response by memory T cells was restricted to the cutaneous lymphocyte-associated antigen (CLA)(+) T-cell subset. ConclusionIgE sensitization to HDM allows stratifying IL-31 production by memory T cells in AD patients and relating it to particular clinical phenotypes of the disease

Prevalence and Predictors of Cerebral Microangiopathy Determined by Pulsatility Index in an Asymptomatic Population From the ILERVAS Project

Background: Little is known about the prevalence of cerebral microangiopathy (CM), which is related to cognitive impairment, in an asymptomatic population. Pulsatility index (PI) is an easily measurable parameter of cerebral vascular resistance in transcranial duplex of the middle cerebral artery (MCA) study. We aimed to determine the prevalence of CM measured by PI of MCA in low to moderate vascular risk subjects. Methods: We included 3,721 subjects between 45 and 70 years without previous history of vascular disease or diabetes mellitus and with at least one other vascular risk factor from the cross-sectional study ILERVAS (Lleida, Spain). Patients underwent transcranial duplex to determine MCA-PI. Possible CM was defined by MCA-PI >1.1. Carotid and femoral arteries ultrasound registration was done to determine the presence, the number, and the area of atheromatous plaques. Body mass index (BMI), pulse pressure (PP) and laboratory data were also recorded. Results: 439 (11.8%) subjects were excluded due to the low quality of transcranial duplex images. Median age was 57 [IQR 52, 62] years. Possible CM was found in 424 (12.9%) subjects. CM patients had higher prevalence of plaques than non-CM (77.4 vs. 66.4%, p < 0.001). PI showed a positive linear correlation with the number of territories with plaques (r = 0.130, p < 0.001), and the total plaque area (r = 0.082, p < 0.001). The predictors of possible CM were the age, male gender, and PP. Conclusions: In low-to-moderate vascular risk asymptomatic population, the proportion of abnormal brain microvascular bed determined by MCA-PI is not negligible. The planned 10-year follow-up will describe the clinical relevance of these findings.This work was supported by grants from the Diputacio de Lleida, Instituto de Salud Carlos III (RETIC RD16/0009/0011) and Ministerio de Ciencia, Inovación y Universidades (IJC2018-037792-I). FP was supported by the Catalan Autonomous Government’s Agència de Gestió d’Ajuts Universitaris i de Recerca (2017 suport a les activitats dels grups de recerca 1628). RP was supported by the Spanish Ministry of Science, Innovation, and Universities (grant RTI2018-099200-B-I00), and the Generalitat of Catalonia: Agency for Management of University and Research Grants (2017SGR696). This study was co-financed by FEDER funds from the European Union (A way to build Europe). IRBLleida is a CERCA Programme/Generalitat of Catalonia

Nanoinformatics: developing new computing applications for nanomedicine

Nanoinformatics has recently emerged to address the need of computing applications at the nano level. In this regard, the authors have participated in various initiatives to identify its concepts, foundations and challenges. While nanomaterials open up the possibility for developing new devices in many industrial and scientific areas, they also offer breakthrough perspectives for the prevention, diagnosis and treatment of diseases. In this paper, we analyze the different aspects of nanoinformatics and suggest five research topics to help catalyze new research and development in the area, particularly focused on nanomedicine. We also encompass the use of informatics to further the biological and clinical applications of basic research in nanoscience and nanotechnology, and the related concept of an extended ?nanotype? to coalesce information related to nanoparticles. We suggest how nanoinformatics could accelerate developments in nanomedicine, similarly to what happened with the Human Genome and other -omics projects, on issues like exchanging modeling and simulation methods and tools, linking toxicity information to clinical and personal databases or developing new approaches for scientific ontologies, among many others