27 research outputs found
Water Stress and Afforestation: A Contribution to Ameliorate Forest Seedling Performance During the Establishment
Chemical Defenses in Eucalyptus Species: A Sustainable Strategy Based on Antique Knowledge to Diminish Agrochemical Dependency
Metabolomics demonstrates divergent responses of two Eucalyptus species to water stress
Past studies of water stress in Eucalyptus spp. generally highlighted the role of fewer than five “important” metabolites, whereas recent metabolomic studies on other genera have shown tens of compounds are affected. There are currently no metabolite profiling data for responses of stress-tolerant species to water stress. We used GC–MS metabolite profiling to examine the response of leaf metabolites to a long (2 month) and severe (Ψpredawn < −2 MPa) water stress in two species of the perennial tree genus Eucalyptus (the mesic Eucalyptus pauciflora and the semi-arid Eucalyptus dumosa). Polar metabolites in leaves were analysed by GC–MS and inorganic ions by capillary electrophoresis. Pressure–volume curves and metabolite measurements showed that water stress led to more negative osmotic potential and increased total osmotically active solutes in leaves of both species. Water stress affected around 30–40% of measured metabolites in E. dumosa and 10–15% in E. pauciflora. There were many metabolites that were affected in E. dumosa but not E. pauciflora, and some that had opposite responses in the two species. For example, in E. dumosa there were increases in five acyclic sugar alcohols and four low-abundance carbohydrates that were unaffected by water stress in E. pauciflora. Re-watering increased osmotic potential and decreased total osmotically active solutes in E. pauciflora, whereas in E. dumosa re-watering led to further decreases in osmotic potential and increases in total osmotically active solutes. This experiment has added several extra dimensions to previous targeted analyses of water stress responses in Eucalyptus, and highlights that even species that are closely related (e.g. congeners) may respond differently to water stress and re-waterin
Impacto de la sombra y la sequía sobre aspectos fisiológicos y de crecimiento en diversos orígenes de E. globulus subsp. globulus
Se estudiaron los efectos combinados de sombra y
sequía en plantas jóvenes de Eucalyptus globulus
subesp. globulus, evaluando cambios en las
características fisiológicas y de crecimiento de tres
procedencias (Jeeralang, Moogara y Pelverata). Las
mismas crecieron bajo tres niveles de disponibilidad
lumínica (pleno sol, sombra moderada, sombra
severa), y dos regímenes hídricos (regadas y bajo
estrés hídrico). El contenido relativo de agua de los
tejidos fue menor en las plantas bajo estrés hídrico, a
pleno sol y sombra moderada. La sequía redujo la
conductancia estomática en Jeeralang y Pelverata, a
pleno sol y sombra moderada. El potencial osmótico
de la célula se redujo por el déficit hídrico en las
plantas de Jeeralang y Moogara, así como en las que
crecían bajo pleno sol y sombra moderada. El
módulo de elasticidad de la pared celular aumentó
por sequía y sombra. El ajuste en las propiedades
osmóticas y elásticas determinó un incremento del
potencial de presión en las plantas estresadas de
pleno sol y sombra moderada. Todas las plantas
sombreadas mostraron menor diámetro, pero sólo las
de sombra severa tuvieron menor altura. La sequía
afectó el diámetro de las plantas que crecían bajo
pleno sol y a las del origen Moogara, pero redujo la
altura de las plantas bajo sombra moderada y del
origen Jeeralang. El área foliar específica aumentó al
disminuir la intensidad de la luz. La supervivencia
fue 100% en todos los tratamientos. Estos resultados
muestran la capacidad de E. globulus subesp.
globulus para tolerar la sequía y la sombra
moderada, si bien se detectó variabilidad entre
procedencias. Este comportamiento podría
interpretarse como una respuesta potencial frente a
condiciones de estrés múltiple de origen biótico y
abiótico y permitiría planificar un manejo más
eficiente en el establecimiento._____________________________The interactive effects of shade and drought were
studied in young plants of Eucalyptus globulus
subsp. globulus, evaluating changes in physiological
and growth characteristics of three provenances
(Jeeralang, Moogara and Pelverata). Plants grew
under three levels of light availability (full sunlight,
moderate shade and severe shade) and two water
regimes (well watered and watered stress). Tissue
relative water content was lower in plants under
water stress, full sunlight and moderate shade.
Drought reduced stomatal conductance in Jeeralang
and Pelverata, under full sunlight and moderate
shade. Osmotic potential decreased due to water
deficit in plants of Jeeralang and Moogara, as well
as in those growing under full sunlight and moderate
shade. Cell wall elasticity modulus increased due to
drought and shade. The adjustment in osmotic and
elastic properties determined an increase in pressure
potential at full turgor in stressed plants at full
sunlight and moderate shade. Shaded plants showed
lower diameter but only those under severe shade
had lower height. Drought affected the diameter of
full sunlight plants and Moogara plants, but reduced
the height of moderate shaded plants and Jeeralang
plants. Specific leaf area increased as the light
intensity diminished. Survival was 100 % in all
treatments. These results show the capacity of E.
globulus subsp. globulus to tolerate drought and
moderate shade, although variability among
provenances was detected. This behavior could be
interpreted as a potential response to biotic and
abiotic multiple stress conditions allowing to plan a
more efficient management during the
establishment
Voiding urgency and detrusor contractility in women with overactive bladders.
To check whether the contractility of overactive bladders would be affected by voiding urgency.We urodynamically studied 100 women: 20 normal controls (group 1), 60 patients with idiopathic detrusor overactivity (DO), and 20 with neurogenic DO from intracerebral lesions. The idiopathic DO groups 2A (n = 20), 2B (n = 20), and 3 (n = 20) had moderate, severe, and no voiding urgency, respectively. The neurogenic DO group 4 had severe urgency. The delay time of urgent void at cystometry (2 minutes or more or, respectively, less than 2 minutes) defined moderate or severe urgency. Detrusor contractility was defined by the maximum bladder external voiding power (WF(max)).WF(max) was higher in the idiopathic DO patients than in the controls, had the highest values in group 2B, and did not differ significantly between groups 1-4 and 2A-3.We inferred from our data that idiopathic DO suggests a facilitation of voiding contractions and that such facilitation might be centrally amplified by severe urgency. This amplifying effect would probably be impaired in cases of neurogenic DO from intracerebral lesions
Urgency of micturition and detrusor contractility in men with prostatic obstruction and overactive bladders
Abstract
Aims.
In men with prostatic obstruction and detrusor overactivity (DO), to ascertain whether urgency of micturition affects bladder contractility.
Materials and Methods.
We urodynamically assessed five groups of 20 men each who had bladder outflow obstruction (BOO) from benign prostatic enlargement—Groups 1 (with no DO and no urgency), 2 (with DO and no urgency), 3A (with DO and moderate urgency), 3B (with DO and severe urgency), and 4 (with DO, severe urgency and chronic ischemic cerebral lesions). Urgency was graded as moderate or severe by the ability to avert an urgent void at cystometry for ≥2 or <2 min, respectively. BOO was assessed by the “Abrams–Griffiths number” (AG) and bladder contractility by the parameters PIP and WFmax.
Results.
AG did not differ significantly in Groups 2, 3A, and 3B, proved higher in such groups than in Group 1, and was nearly the same in Groups 1 and 4. PIP and WFmax were significantly higher in Groups 2, 3A, and 3B than in Groups 1 and 4, had the highest levels in Group 3B, and did not differ significantly in Groups 1–4 and 2–3A.
Conclusions.
In DO patients with prostatic obstruction there seems to be a DO-related facilitation of bladder contractility. In the same patients, severe urgency of micturition might over-amplify (i.e., enhance a DO-related facilitation of) bladder contractility, provided there are no neurogenic (chronic ischemic cerebral) lesions
Urgency of micturition and detrusor contractility in men with prostatic obstruction and overactive bladders
The potential role of brachytherapy in the irradiation of patients with lung cancer: a systematic review
What makes voters turn out: the effects of polls and beliefs
We use laboratory experiments to test for one of the foundations of the rational voter paradigm - that voters respond to probabilities of being pivotal. We exploit a setup that entails stark theoretical effects of information concerning the preference distribution (as revealed through polls) on costly participation decisions. The data reveal several insights. First, voting propensity increases systematically with subjects' predictions of their preferred alternative's advantage. Consequently, pre-election polls do not exhibit the detrimental welfare effects that extant theoretical work predicts. They lead to more participation by the expected majority and generate more landslide elections. Finally, we investigate subjects' behavior in polls and identify when Bandwagon and Underdog Effects arise