173 research outputs found

    Susceptibility to Melampsora leaf rust of poplar clones from diverse genetic backgrounds: effects on photochemistry and water relations

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    The selection of resistant genotypes is the most appropriate approach in the prevention of the reduction of biomass and mortality caused by rust infection in poplar plantations. Thus, it is pertinent that we improve our understanding of the consequences that this fungal disease has on leaf physiology. Here, we studied the susceptibility to Melampsora rust in three different poplar clones of commercial interest: Lux clone - Populus deltoides Batr. (cottonwood) and Luisa Avanzo and Adige clones - both Populus × canadensis Mönch. The most susceptible clone to the infection was L. Avanzo whereas Lux and especially Adige were only slightly affected. The propagation of the disease was very rapid in L. Avanzo; their leaves showed a high incidence and severity of the disease in early and advanced stages of infection as was clearly evidenced by the degree of infection. Infected leaves of L. Avanzo were shown to have drought impaired water relations during summer as reflected by the marked decline in the relative water content (RWC). Chlorophyll fluorescence imaging revealed heterogeneity of the effect of the pathogen in the leaves, and areas with pustules showed low maximum quantum yield (Fv/Fm) and PSII quantum yield (?PSII) values, indicative of strong photoinhibition. In L. Avanzo, with a greater pustule density, rust provoked a decline in whole leaf photochemistry as indicated by Fv/Fm and photochemical reflectance index (PRI) results. Leaf structural parameters were not affected by the disease but results in L. Avanzo and Lux showed higher leaf mass per area (LMA) and higher leaf density (D) indicating an adaptation to increasing summer drought. In all clones, the effect of the pathogen was reflected in lower leaf chlorophyll content

    Carbon sequestration in Mediterranean ecosystems: critical aspects related to plant respiration, wildfires and nitrogen budget

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    La producció primària neta (NPP) de la biosfera està limitada pels baixos nivells actuals de CO2 atmosfèric (Ca). Per conseqüent, l'augment de Ca degut a l'activitat humana, considerat la causa principal del canvi climàtic, s'hauria de traduir en un augment de la NPP i, per tant, en un augment del segrestament de Ca a la biomassa. Els augments de NPP i del segrestament de Ca ja són detectables en boscos boreals i tropicals. L'augment de Ca produeix també una disminució de la respiració vegetal ?un 17 % de mitjana?, fet que podria provocar que el segrestament de Ca fos més gran que no s'havia previst. Aquests resultats han fet que alguns autors ofereixin visions força optimistes sobre la capacitat dels ecosistemes terrestres per compensar l'excés de Ca. No obstant això, l'augment de Ca no es tradueix només en un augment de la NPP (diferent per a cada espècie), sinó també en canvis en la morfologia de la planta (també diferents per a cada espècie), que comportaran canvis en els patrons d'ocupació de l'espai, que fan difícil predir en quin sentit canviarà la NPP a llarg termini en l'ecosistema sencer. No és gens clar que aquestes previsions optimistes siguin aplicables als ecosistemes terrestres mediterranis, en els quals la sequera ?principal factor limitant de la NPP? s'espera que s'agreugi en un futur, com a conseqüència del canvi climàtic. L'agreujament de la sequera es pot traduir en un augment del risc d'incendi, fet que pot conduir els ecosistemes mediterranis a una situació de gran inestabilitat, en cas que la periodicitat i la intensitat dels focs superin llur capacitat de recuperació (per germinació o rebrot). L'incendi implica pèrdues importants de N i P per volatilització; també provoca un fort augment de la disponibilitat de nutrients (sobretot N) i, doncs, un augment de la fertilitat del sòl. Moltes espècies mediterrànies, i en concret l'alzina (Quercus ilex), tenen una gran capacitat d'acumular N en òrgans basals, probablement per facilitar un rebrot ràpNet primary production (NPP) in the biosphere is limited by the current low atmospheric CO2 concentration (Ca). Hence, the increase in Ca due to anthropogenic activities, which is thought to be the main cause of climate change, is expected to result in an increase in NPP, and therefore in an increased Ca sequestration in the biomass. Increases in NPP and Ca sequestration in the biota are already detectable in boreal and tropical forests. Increased Ca results in a decrease in plant respiration ?on average, about 17%?, and therefore the increase in Ca sequestration could be higher than previously assumed. This has led some authors to publish highly optimistic views about the capacity of terrestrial ecosystems to compensate for the excess of Ca. Nevertheless, increased Ca results not only in an increase in NPP (different for every plant species), but also in changes in plant morphology (also different for every plant species); these will result in changes in the patterns of space occupation by plants, which make it difficult to predict how the NPP will change in the long term, at a whole-ecosystem level. It is not clear that such optimistic views can be applied to Mediterranean terrestrial ecosystems, in which drought ?the main constraint for NPP? is expected to increase in the future as a result of climate change. Increased drought is expected to lead to a greater risk of wildfires, which can generate a highly unstable situation in the ecosystem if the periodicity and intensity of fire events surpasses its capacity to recover (either by resprouting or seeding). Wildfires cause significant losses of N and P by volatilization. They also result in a strong increase in the availability of nutrients (mainly N), and hence an increase in soil fertility

    Implementation of Group Interpersonal Psychotherapy in primary care

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    OBJECTIVE To show the implementation process of IPT-G in primary care, including facilitating and obstructing factors, implementation strategies, and training and supervision of primary care professionals. METHODS Quantitative (cross-sectional and longitudinal) analysis of pre and post-knowledge tests; qualitative analyses of the training courses; patient recruitment; conduction of IPT-G sessions; supervision of IPT-G therapists; application of a semi-structured questionnaire to assess, investigate, and develop strategies against the identified barriers. RESULTS About 120 clinicians answered the pre-test; 84 completed the post-test. Pre- and post-test scores of IPT-G knowledge were significantly different. Twenty initially trained clinicians completed additional supervision in IPT-G. Qualitative analysis identified twelve barriers and six facilitators to IPT-G implementation in individual, organizational, and systemic contexts. CONCLUSIONS Implementation of IPT-G in primary care is a complex process with several steps. In the first step, health professionals were successfully trained in IPT-G. However, subsequent steps were more complex. Therefore, careful planning of IPT-G implementation is essential to maximize the success of this innovation

    Wbp2 is required for normal glutamatergic synapses in the cochlea and is crucial for hearing

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    WBP2 encodes the WW domain-binding protein 2 that acts as a transcriptional coactivator for estrogen receptor a (ESR1) and progesterone receptor (PGR). We reported that the loss of Wbp2 expression leads to progressive high-frequency hearing loss in mouse, as well as in two deaf children, each carrying two different variants in the WBP2 gene. The earliest abnormality we detect in Wbp2-deficient mice is a primary defect at inner hair cell afferent synapses. This study defines a new gene involved in the molecular pathway linking hearing impairment to hormonal signalling and provides new therapeutic targets

    Health, education, and social care provision after diagnosis of childhood visual disability

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    Aim: To investigate the health, education, and social care provision for children newly diagnosed with visual disability.Method: This was a national prospective study, the British Childhood Visual Impairment and Blindness Study 2 (BCVIS2), ascertaining new diagnoses of visual impairment or severe visual impairment and blindness (SVIBL), or equivalent vi-sion. Data collection was performed by managing clinicians up to 1-year follow-up, and included health and developmental needs, and health, education, and social care provision.Results: BCVIS2 identified 784 children newly diagnosed with visual impairment/SVIBL (313 with visual impairment, 471 with SVIBL). Most children had associated systemic disorders (559 [71%], 167 [54%] with visual impairment, and 392 [84%] with SVIBL). Care from multidisciplinary teams was provided for 549 children (70%). Two-thirds (515) had not received an Education, Health, and Care Plan (EHCP). Fewer children with visual impairment had seen a specialist teacher (SVIBL 35%, visual impairment 28%, χ2p < 0.001), or had an EHCP (11% vs 7%, χ2p < 0 . 01).Interpretation: Families need additional support from managing clinicians to access recommended complex interventions such as the use of multidisciplinary teams and educational support. This need is pressing, as the population of children with visual impairment/SVIBL is expected to grow in size and complexity.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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