2,785 research outputs found
Nitric oxide alleviates cadmium- but not arsenic-induced damages in rice roots
Nitric oxide (NO) has signalling roles in plant stress responses. Cadmium (Cd) and arsenic (As) soil pollutants alter plant development, mainly the root-system, by increasing NO-content, triggering reactive oxygen species (ROS), and forming peroxynitrite by NO-reaction with the superoxide anion. Interactions of NO with ROS and peroxynitrite seem important for plant tolerance to heavy metal(oid)s, but the mechanisms underlying this process remain unclear. Our goal was to investigate NO-involvement in rice (Oryza sativa L.) root-system after exposure to Cd or As, to highlight possible differences in NO-behaviour between the two pollutants. To the aim, morpho-histological, chemical and epifluorescence analyses were carried out on roots of different origin in the root-system, under exposure to Cd or As, combined or not with sodium nitroprusside (SNP), a NO-donor compound. Results show that increased intracellular NO levels alleviate the root-system alterations induced by Cd, i.e., inhibition of adventitious root elongation and lateral root formation, increment in lignin deposition in the sclerenchyma/endodermis cell-walls, but, even if reducing As-induced endodermis lignification, do not recover the majority of the As-damages, i.e., enhancement of AR-elongation, reduction of LR-formation, anomalous tissue-proliferation. However, NO decreases both Cd and As uptake, without affecting the pollutants translocation-capability from roots to shoots. Moreover, NO reduces the Cd-induced, but not the As-induced, ROS levels by triggering peroxynitrite production. Altogether, results highlight a different behaviour of NO in modulating rice root-system response to the toxicity of the heavy metal Cd and the metalloid As, which depends by the NO-interaction with the specific pollutant
Cadmium and arsenic affect root development in Oryza sativa L. negatively interacting with auxin
Cadmium (Cd) and arsenic (As), non essential, but toxic, elements for animals and plants are frequently present in paddy fields. Oryza sativa L., a staple food for at least the half of world population, easily absorbs As and Cd by the root, and in this organ the pollutants evoke consistent damages, reducing/modifying the root system. Auxins are key hormones in regulating all developmental processes, including root organogenesis. Moreover, plants respond to environmental stresses, such as those caused by Cd and As, by changing levels and distribution of endogenous phytohormones. Even though the effects of Cd and As on the roots have been investigated in some species, it remains necessary to deepen the knowledge about the cross-talk between these toxic elements and auxin during root formation and development, in particular in agronomically important plants, such as rice. Hence, the research goal was to investigate the interactions between Cd and As, alone or combined, and auxin during the development of rice roots. To reach the aim, morphological, histological and histochemical analyses were carried out on seedlings, exposed or not to Cd and/or As, belonging to the wild type and transgenic lines useful for monitoring indole-3-acetic acid (IAA) localization, i.e., OsDR5:GUS, and IAA cellular influx and efflux, i.e., OsAUX1:GUS and OsPIN5b:GUS. Moreover, the transcript levels of the YUCCA2 and ASA2, IAA biosynthetic genes were also monitored in Cd and/or As exposed wild type seedlings. The results highlight that As and Cd affect cyto-histology and morphology of the roots. In particular, they alter the lateral root primordia organization and development with negative consequences on root system architecture. This is due to a disturbance of IAA biosynthesis and transport, as indicated by the altered expression of both ASA2 and YUCCA2 biosynthetic genes, and AUX1 and PIN5b transporter genes
Elliptic CMB Sky
The ellipticity of the anisotropy spots of the Cosmic Microwave Background
measured by the Wilkinson Microwave Anisotropy Probe (WMAP) has been studied.
We find an average ellipticity of about 2, confirming with a far larger
statistics similar results found first for the COBE-DMR CMB maps, and then for
the BOOMERanG CMB maps. There are no preferred directions for the obliquity of
the anisotropy spots. The average ellipticity is independent of temperature
threshold and is present on scales both smaller and larger than the horizon at
the last scattering. The measured ellipticity characteristics are consistent
with being the effect of geodesics mixing occurring in an hyperbolic Universe,
and can mark the emergence of CMB ellipticity as a new observable constant
describing the Universe. There is no way of simulating this effect. Therefore
we cannot exclude that the observed behavior of the measured ellipticity can
result from a trivial topology in the popular flat -CDM model, or from
a non-trivial topology.Comment: 10 pages, 5 figures, the version to appear in Mod.Phys.Lett.
Towards joint reconstruction of noise and losses in quantum channels
The calibration of a quantum channel, i.e. the determination of the
transmission losses affecting it, is definitely one of the principal objectives
in both the quantum communication and quantum metrology frameworks. Another
task of the utmost relevance is the identification, e.g. by extracting its
photon number distribution, of the noise potentially present in the channel.
Here we present a protocol, based on the response of a photon-number-resolving
detector at different quantum efficiencies, able to accomplish both of these
tasks at once, providing with a single measurement an estimate of the
transmission losses as well as the photon statistics of the noise present in
the exploited quantum channel. We show and discuss the experimental results
obtained in the practical implementation of such protocol, with different kinds
and levels of noise.Comment: 6 pages, 4 figure
Cambiamento climatico, inquinamento atmosferico e aumento delle allergie respiratorie: solo una coincidenza o qualcosa di piĂą? [Climate change, air pollution, and increase of respiratory allergies: just a coincidence or something more?].
It is well known that the prevalence of respiratory allergies has increased over time. At the same time, climate change has become part of our everyday life. The resulting question is whether this 'allergic epidemic' is linked to this aspect. It is assumed that the causes of the increase of respiratory allergies are mainly related to environmental factors and lifestyle: first, the improvement of social and health conditions and related hygiene hypothesis; secondly, lifestyle change and anthropogenic activities, which have caused an alteration in the balance normally existing between soil, water, and atmosphere, giving rise to the phenomena of climate change. In fact, it has been demonstrated that they can influence beginning, duration, and intensity of the pollen season, as well as the allergenicity of pollen. The consequence is both an increase in frequency and intensity of allergic symptomatology in subjects previously affected by allergy, and a promotion of the sensitization of the airways to allergens present in the atmosphere in predisposed subjects. Several intervention strategies aiming to mitigate climate change and reduce anthropogenic emissions and, consequently, respiratory allergies are possible and can be implemented on an individual and social level. It follows that the allergist cannot solve the problem of the progressive increase of respiratory allergies on his own. Anyway, his role can have both clinical and educational purposes with a special commitment to reduce health impact due to environmental risk factors. KEYWORDS: respiratory allergies; allergenic potential of pollen; climate change; pollution
Investigating Habituation to Premonitory Urges in Behavior Therapy for Tic Disorders
Behavior therapy is effective for Persistent Tic Disorders (PTDs), but behavioral processes facilitating tic reduction are not well understood. One process, habituation, is thought to create tic reduction through decreases in premonitory urge severity. The current study tested whether premonitory urges decreased in youth with PTDs (N = 126) and adults with PTDs (N = 122) who participated in parallel randomized clinical trials comparing behavior therapy to psychoeducation and supportive therapy (PST). Trends in premonitory urges, tic severity, and treatment outcome were analyzed according to the predictions of a habituation model, whereby urge severity would be expected to decrease in those who responded to behavior therapy. Although adults who responded to behavior therapy showed a significant trend of declining premonitory urge severity across treatment, results failed to demonstrate that behavior therapy specifically caused changes in premonitory urge severity. In addition, reductions in premonitory urge severity in those who responded to behavior therapy were significant greater than those who did not respond to behavior therapy but no different than those who responded or did not respond to PST. Children with PTDs failed to show any significant changes in premonitory urges. Reductions in premonitory urge severity did not mediate the relationship between treatment and outcome in either adults or children. These results cast doubt on the notion that habituation is the therapeutic process underlying the effectiveness of behavior therapy, which has immediate implications for the psychoeducation and therapeutic rationale presented in clinical practice. Moreover, there may be important developmental changes in premonitory urges in PTDs, and alternative models of therapeutic change warrant investigation
Benchmarking Treatment Response in Tourette’s Disorder: A Psychometric Evaluation and Signal Detection Analysis of the Parent Tic Questionnaire
This study assessed the psychometric properties of a parent-reported tic severity measure, the Parent Tic Questionnaire (PTQ), and used the scale to establish guidelines for delineating clinically significant tic treatment response. Participants were 126 children ages 9 to 17 who participated in a randomized controlled trial of Comprehensive Behavioral Intervention for Tics (CBIT). Tic severity was assessed using the Yale Global Tic Severity Scale (YGTSS), Hopkins Motor/Vocal Tic Scale (HMVTS) and PTQ; positive treatment response was defined by a score of 1 (very much improved) or 2 (much improved) on the Clinical Global Impressions – Improvement (CGI-I) scale. Cronbach’s alpha and intraclass correlations (ICC) assessed internal consistency and test-retest reliability, with correlations evaluating validity. Receiver- and Quality-Receiver Operating Characteristic analyses assessed the efficiency of percent and raw-reduction cutoffs associated with positive treatment response. The PTQ demonstrated good internal consistency (α = 0.80 to 0.86), excellent test-retest reliability (ICC = .84 to .89), good convergent validity with the YGTSS and HM/VTS, and good discriminant validity from hyperactive, obsessive-compulsive, and externalizing (i.e., aggression and rule-breaking) symptoms. A 55% reduction and 10-point decrease in PTQ Total score were optimal for defining positive treatment response. Findings help standardize tic assessment and provide clinicians with greater clarity in determining clinically meaningful tic symptom change during treatment
Pharmaceutical particles design by membrane emulsification: preparation methods and applications in drug delivery
© 2017 Bentham Science Publishers.Nowadays, the rational design of particles is an important issue in the development of pharmaceutical medicaments. Advances in manufacturing methods are required to design new pharmaceutical particles with target properties in terms of particle size, particle size distribution, structure and functional activity. Membrane emulsification is emerging as a promising tool for the production of emulsions and solidified particles with tailored properties in many fields. In this review, the current use of membrane emulsification in the production of pharmaceutical particles is highlighted. Membrane emulsification devices designed for small-scale testing as well as membrane-based methods suitable for large-scale production are discussed. A special emphasis is put on the important factors that contribute to the encapsulation efficiency and drug loading. The most recent studies about the utilization of the membrane emulsification for preparing particles as drug delivery systems for anticancer, proteins/peptide, lipophilic and hydrophilic bioactive drugs are reviewed
The use of inhaled corticosteroid in preschool wheezers: what's the point today?
Among the preschool children who wheeze two different groups can be identify: children who have a viral infection and those who respond to multiple triggers, such as exercise or allergens
Moderators and Predictors of Response to Behavior Therapy for Tics in Tourette Syndrome
Objective: To examine moderators and predictors of response to behavior therapy for tics in children and adults with Tourette syndrome and chronic tic disorders. Methods: Data from 2 10-week, multisite studies (1 in children and 1 in adults; total n = 248) comparing comprehensive behavioral intervention for tics (CBIT) to psychoeducation and supportive therapy (PST) were combined for moderator analyses. Participants (177 male, 71 female) had a mean age of 21.5 ± 13.9 years (range 9–69). Demographic and clinical characteristics, baseline tic-suppressing medication, and co-occurring psychiatric disorders were tested as potential moderators for CBIT vs PST or predictors of outcome regardless of treatment assignment. Main outcomes measures were the Yale Global Tic Severity Scale Total Tic score and the Clinical Global Impression–Improvement score assessed by masked evaluators. Results: The presence of tic medication significantly moderated response to CBIT vs PST (p = 0.01). Participants showed tic reduction after CBIT regardless of tic medication status, but only participants receiving tic medication showed reduction of tics after PST. Co-occurring psychiatric disorders, age, sex, family functioning, tic characteristics, and treatment expectancy did not moderate response. Across both treatments, greater tic severity (p = 0.005) and positive participant expectancy (p = 0.01) predicted greater tic improvement. Anxiety disorders (p = 0.042) and premonitory urge severity (p = 0.005) predicted lower tic reduction. Conclusions: Presence of co-occurring attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, or anxiety disorders did not moderate response to CBIT. Although participants on tic medication showed improvement after CBIT, the difference between CBIT and PST was greater for participants who were not on tic-suppressing medication. ClinicalTrials.gov identifiers: The child and adult CBIT studies are listed on clinical trials.gov (NCT00218777 and NCT00231985, respectively). Classification of evidence: This study provides Class I evidence that CBIT is effective in reducing tic severity across subgroups of patients with chronic tic disorders, although the difference between treatments was smaller for participants on tic-suppressing medications, suggesting reduced efficacy in this subgroup
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