Many studies have reported that hydraulic properties vary considerably between tree species, but little is known about their intraspecific variation and, therefore, their capacity to adapt to a ...warmer and drier climate. Here, we quantify phenotypic divergence and clinal variation for embolism resistance, hydraulic conductivity and branch growth, in four tree species, two angiosperms (Betula pendula, Populus tremula) and two conifers (Picea abies, Pinus sylvestris), across their latitudinal distribution in Europe. Growth and hydraulic efficiency varied widely within species and between populations. The variability of embolism resistance was in general weaker than that of growth and hydraulic efficiency, and very low for all species but Populus tremula. In addition, no and weak support for a safety vs. efficiency trade-off was observed for the angiosperm and conifer species, respectively. The limited variability of embolism resistance observed here for all species except Populus tremula, suggests that forest populations will unlikely be able to adapt hydraulically to drier conditions through the evolution of embolism resistance.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
AIMS: To evaluate the impact of the amount and distribution of soil water on xylem anatomy and xylem hydraulics of current-year shoots, plant water status and stomatal conductance of mature ...‘Manzanilla’ olive trees. METHODS: Measurements of water potential, stomatal conductance, hydraulic conductivity, vulnerability to embolism, vessel diameter distribution and vessel density were made in trees under full irrigation with non-limiting soil water conditions, localized irrigation, and rain-fed conditions. RESULTS: All trees showed lower stomatal conductance values in the afternoon than in the morning. The irrigated trees showed water potential values around −1.4 and −1.6 MPa whereas the rain-fed trees reached lower values. All trees showed similar specific hydraulic conductivity (K ₛ) and loss of conductivity values during the morning. In the afternoon, K ₛ of rain-fed trees tended to be lower than of irrigated trees. No differences in vulnerability to embolism, vessel-diameter distribution and vessel density were observed between treatments. CONCLUSIONS: A tight control of stomatal conductance was observed in olive which allowed irrigated trees to avoid critical water potential values and keep them in a safe range to avoid embolism. The applied water treatments did not influence the xylem anatomy and vulnerability to embolism of current-year shoots of mature olive trees.
Abstract
Climate change is expected to increase the frequency and intensity of droughts and heatwaves in Europe, leading to effects on forest growth and major forest dieback events due to hydraulic ...failure caused by xylem embolism. Inter-specific variability in embolism resistance has been studied in detail, but little is known about intra-specific variability, particularly in marginal populations. We evaluated 15 European beech populations, mostly from geographically marginal sites of the species distribution range, focusing particularly on populations from the dry southern margin. We found small, but significant differences in resistance to embolism between populations, with xylem pressures causing 50% loss of hydraulic conductivity ranging from −2.84 to −3.55 MPa. Significant phenotypic clines of increasing embolism resistance with increasing temperature and aridity were observed: the southernmost beech populations growing in a warmer drier climate and with lower habitat suitability have higher resistance to embolism than those from Northern Europe growing more favourable conditions. Previous studies have shown that there is little or no difference in embolism resistance between core populations, but our findings show that marginal populations have developed ways of protecting their xylem based on either evolution or plasticity.
The Granada group in BNCT research is currently performing studies on: nuclear and radiobiological data for BNCT, new boron compounds and a new design for a neutron source for BNCT and other ...applications, including the production of medical radioisotopes. All these activities are described in this report.
•Basic research activities at two international facilities: CERN and ILL are shown.•Obtention of accurate nuclear and radiobiological data for reducing uncertainties in treatment planning is pursued.•The conceptual design of a facility for BNCT and isotope production is described.
Display omitted
•Engineering aspects of hydrothermal pretreatment are presented.•Hydrothermal pretreatment stage plays an important role in the biorefinery concept.•Hydrothermal pretreatment and ...their effect on biomass structure.•Operation mode in batch and continuous of hydrothermal pretreatment are discuses.
Different pretreatments strategies have been developed over the years mainly to enhance enzymatic cellulose degradation. In the new biorefinery era, a more holistic view on pretreatment is required to secure optimal use of the whole biomass. Hydrothermal pretreatment technology is regarded as very promising for lignocellulose biomass fractionation biorefinery and to be implemented at the industrial scale for biorefineries of second generation and circular bioeconomy, since it does not require no chemical inputs other than liquid water or steam and heat. This review focuses on the fundamentals of hydrothermal pretreatment, structure changes of biomass during this pretreatment, multiproduct strategies in terms of biorefinery, reactor technology and engineering aspects from batch to continuous operation. The treatise includes a case study of hydrothermal biomass pretreatment at pilot plant scale and integrated process design.
By presenting sea surface temperatures, planktonic oxygen isotope profiles, and bulk geochemical composition of core sediments, we offer a multiparameter reconstruction of Western Mediterranean ...oceanography from the Last Glacial Maximum until the Middle Holocene (20,000–5000 cal years B. P.). Sediments from Ocean Drilling Program Site 975 in the Algero‐Balearic basin have been compared with three Alboran basin cores (TTR‐300G, TTR‐302G, and TTR‐304G), all of them investigated at high resolution. This multiproxy approach has allowed two different modes of circulation to be recognized: (1) during the LGM and from ∼8.0 cal. ka B. P. onward, no surface gradient in δ18OG. bulloides is found associated with low productivity, in close analogy to modern conditions; (2) during the Bølling‐Allerød and early Holocene, significant surface isotopic gradients are found with periods probably indicating an unstable water column, associated with enhanced productivity and low bottom oxygen conditions. The close synchrony between the occurrence of the surface isotopic offset and organic rich layer formation implicates that the origin of these features is linked, probably via shoaling of the regional thermohaline circulation. Paleo‐SSTs, derived from planktonic foraminifer assemblages, indicate abrupt changes in surface conditions during the analyzed time interval. Fluctuations in marine productivity based on Ba and total organic carbon are related to water column stability and atmospheric conditions. A sharp warming and δ18OG. bulloides excursion at the end of the Younger Dryas is probably linked to glacial meltwater influence. The riverine input has been reconstructed using the Mg/Al ratio, and Mg/Al peaks during arid periods (Greenland Stadial‐2a and Younger Dryas) related to “bypass” margin processes.
To cite this article: Torres MJ, Ariza A, Fernández J, Moreno E, Laguna JJ, Montañez MI, Ruiz-Sanchez AJ, Blanca M. Role of minor determinants of amoxicillin in the diagnosis of immediate allergic ...reactions to amoxicillin. Allergy 2010; 65: 590-596. Skin testing of subjects with immediate hypersensitivity to amoxicillin is performed using major and minor determinants of benzylpenicillin plus amoxicillin. However, sensitivity is not optimal, and other determinants need to be considered. We assessed the sensitivity of stable, well-characterized minor determinants of amoxicillin in subjects with immediate allergic reactions to amoxicillin to improve skin test sensitivity. Amoxicillin, amoxicilloic acid, and diketopiperazine were prepared and characterized by reverse-phase HPLC, tested in vivo by skin testing and in vitro by basophil activation test and RAST inhibition assay. Patients with immediate hypersensitivity to amoxicillin were selected: Group A (n = 32), skin test positive just to amoxicillin; Group B (n = 19), skin test positive to benzylpenicillin determinants; Group C (n = 10), skin test negative and amoxicillin drug provocation test positive. In Group A, 27 subjects (81.8%) were skin test positive to amoxicillin, ten (30.3%) to amoxicilloic acid, two (6.1%) to diketopiperacine, and six (18.2%) negative. In Group B, nine (50%) were positive to amoxicillin, eight (42.1%) to amoxicilloic acid, none to diketopiperacine, and nine (50%) negative. In Group C, skin tests were negative. BAT was positive to amoxicillin in 26 patients (50.9%), to amoxicilloic acid in 15 (29.1%), and diketopiperazine in four (7.8%). RAST inhibition studies showed > 50% inhibition in all sera, with the highest concentration of amoxicillin and amoxicilloic acid. The combination of minor determinants of amoxicillin, amoxicilloic acid, and diketopiperazine seems to be of no greater value than the use of amoxicillin alone. Further efforts are needed to find new structures to improve sensitivity in the diagnosis of immediate hypersensitivity to betalactams.
► When
Ψ
stem
<
−1.7
MPa half-inversed or completely inversed diurnal
P
p curves were recorded. ► This was reversible: normal
P
p curves were recorded within a few days after rewatering. ► ...Information on water stress was derived from the inversed
P
p curves. ► An early detection of water stress can be achieved with LPCP probes installed in the east part of the canopy. ► The LPCP probe is an advantageous alternative to the pressure chamber in hedgerow olive orchards.
The need for sophisticated irrigation strategies in fruit tree orchards has led to an increasing interest in reliable and robust sensor technology that allows automatic and continuous recording of the water stress of trees under field conditions. In this work we have evaluated the potential of the leaf patch clamp pressure (LPCP) probe for monitoring water stress in a 4-year-old ‘Arbequina’ hedgerow olive orchard with 1667
trees
ha
−1. The leaf patch output pressure (
P
p) measured by the LPCP probe is inversely correlated with the leaf turgor pressure (>50
kPa). Measurements of
P
p were made over the entire irrigation season of 2010 (April to November) on control trees, irrigated up to 100% of the crop water needs (ET
c), and on trees under two regulated deficit irrigation (RDI) strategies. The 60RDI trees received 59.2% of ET
c and the 30RDI trees received 29.4% of ET
c. In the case of the RDI trees the irrigation amounts were particularly low during July and August, when the trees are less sensitive to water stress. At severe water stress levels (values of stem water potential dropped below ca. −1.70
MPa; turgor pressure
<
50
kPa) half-inversed or completely inversed diurnal
P
p curves were observed. Reason for these phenomena is the accumulation of air in the leaves. These phenomena were reversible. Normal diurnal
P
p profiles were recorded within a few days after rewatering, the number depending on the level of water stress previously reached. This indicates re-establishment of turgescence of the leaf cells. Crucial information about severe water stress was derived from the inversed diurnal
P
p curves. In addition
P
p values measured on representative trees of all treatments were compared with balancing pressure (
P
b) values recorded with a pressure chamber on leaves taken from the same trees or neighbored trees exposed to the same irrigation strategies. Concomitant diurnal
P
b measurements were performed in June and September, i.e. before and after the period of great water stress subjected to RDI trees. Results showed close relationships between
P
p and
P
b, suggesting that the pressure chamber measures relative turgor pressure changes as the LPCP probe. Therefore the probe seems to be an advantageous alternative to the pressure chamber for monitoring tree water status in hedgerow olive tree orchards.
Purpose: To analyse outcome and prognostic factors for overall survival (OS) and time to treatment failure (TTF) in 357 patients with Hodgkin's lymphoma (HL) undergoing an autologous stem cell ...transplantation (ASCT) after a first relapse and reported to the The Grupo Español de Linfomas/Trasplante Autólogo de Médula Osea (GEL/TAMO) Cooperative Group. Methods: Two hundred and twenty males and 137 females with a median age of 29 years were autografted in second remission (n=181), first sensitive relapse (n=148) and first resistant relapse (n=28). Results: Five-year actuarial TTF and OS were of 49% ± 3% and 57% ± 3%. Advanced stage at diagnosis, complementary radiotherapy before ASCT, a short first complete response (CR) and detectable disease at ASCT adversely influenced TTF. Year of transplant ≤1995, bulky disease at diagnosis, a short first CR, detectable disease at ASCT and ≥1 extranodal areas involved at ASCT were adverse factors for OS. Conclusions: ASCT constitutes a therapeutic option for HL patients after a first relapse. Promising results are observed in patients with low tumour burden at diagnosis, autografted after a long CR and without detectable disease at ASCT. Innovative approaches should be pursued for patients with risk factors at relapse.
PDF
