Display omitted
•Morpho-physiological traits were studied in 3 cardoon cvs. grown on a polluted soil.•Metals induced severe ultrastructural damage in Sardo and Siciliano cvs.•Pigments and ...photochemistry showed a significant decline in Sardo and Sicilano cvs.•Rubisco protein significantly increases in Spagnolo cv.•Spagnolo cv. faces metal stress by balancing morphology and physiology.
In the present work the cytomorphological and physiological effects on three cardoon cultivars – Sardo, Siciliano, Spagnolo - grown in a metal-polluted soil, were investigated, to assess the traits concurring to the high tolerance to metal stress observed in cv. Spagnolo compared to the other two cultivars. The plants were grown for one month on a real polluted soil collected at a dismantling battery plant, highly enriched by heavy metals, especially Cd and Pb, and their leaves were analyzed by a multidisciplinary approach. TEM observations highlighted severe ultrastructural damage in Sardo and Siciliano, and preserved cytological traits in Spagnolo. Both pigment content and photochemistry indicated a decline in photosynthesis in Sardo and Sicilano and a substantial stability of the same parameters in Spagnolo. Protein analysis indicated a decrease in D1 level in all cultivars; in Spagnolo the D1 decrease was more pronounced and associated to a significant increase in Rubisco, a pattern likely preserving photosynthetic efficiency and high biomass production. In conclusion, Spagnolo cardoon was able to face metal stress through a prompt, multiple response balancing structural and functional traits.
Help seeking is a key component of many systems of self-regulated learning (SRL). Prior research has noted how motivational and other aspects of SRL relate to students' engagement in help seeking and ...endorsement of types of help seeking (i.e., adaptive, expedient, and avoidant). This study examines specific antecedents to help seeking--monitoring accuracy, perceived need for help, and value for help seeking--as both domain-general (between students) and domain-specific (within students) aspects of help seeking in a sample of upper elementary students. Drawing on self-reports, teacher-reports, and assessments, results show that antecedents' relations with help seeking vary at the level of measurement (within or between students), type of reporter (student vs. teacher), and characterization of help (adaptive vs. expedient). Results present a complicated picture of students' classroom help seeking, supporting some theoretical links and laying the stage for further study of help seeking across contexts among elementary students.
•Mastery classrooms positively associated with help from peers and instrumental help.•Performance-approach classrooms inversely associated with seeking help from teacher.•Emotional support positively ...associated with seeking help from teacher and peers.•Instrumental help and seeking help from teacher linked with math test score gains.•Developmental and gender differences in help seeking were found.
We examined the relation between self reported help-seeking tendencies and standardized mathematics achievement as well as the contribution of shared perceptions of the classroom climate – achievement goal structure and emotional support – to the types of help (instrumental, expedient) middle and high school U.S. students seek and from whom (teacher and peers) over the school year. Hierarchical linear modeling (N = 3897 students grades 7–11 in 306 classrooms) revealed that the more students reported seeking help from their teacher and seeking instrumental help, the greater their over-the-year gains in standardized achievement. In general, shared perceptions of the classroom climate predicted changes in students' reported help seeking from the beginning of the school year (T1) to the end (T2). Students in classrooms collectively perceived to be more mastery-oriented at T1 predicted increases in instrumental help seeking and seeking help from peers at T2. Perceived T1 emotional support predicted increases in seeking help from teachers and peers at T2. By contrast, perceived T1 performance-approach goal structure predicted decreases in reported help seeking from teachers at T2 and positively predicted expedient help seeking at T2. Furthermore: (a) adolescent females reported seeking more instrumental help and seeking more help from peers and teachers, whereas, adolescent males reported seeking more expedient help; and (b) high school students sought more instrumental help than did middle school students. We discuss results with regard to the importance of help seeking to mathematics achievement as well as considering emotional support and classroom achievement goals together when examining students' help-seeking behaviors.
The effects of cadmium and lead were investigated in Cynara cardunculus L. Plant uptake by root and shoot, changes in cell ultrastructure and photosynthetic efficiency, photosynthetic key protein ...levels, as well as regulation of stress-induced Hsp70 were examined. Cynara cardunculus accumulated Cd and Pb in their tissue, with a different trend for the two metals. The prompt translocation of Cd to the shoot may justify the ultrastructural injuries, especially observed in chloroplasts. However, Cd- treated plants did not show any decline in photochemistry; it is likely that Cd in shoot tissue triggers defense mechanisms, increasing the level of proteins involved in photosynthesis (i.e., Rubisco and D1 increased 7 and 4.5 fold respectively) as a compensatory response to neutralize chloroplast damage. The accumulation of Pb mainly in root, can explain the increase in Hsp70 level (23 folds) in this tissue. Pb reached the shoots, even at low amounts, causing an overall significant change in some photochemical parameters (QY and NPQ decreases and increases of 25%, respectively). The results suggest a higher sensitivity of C. cardunculus to Pb than Cd, although maximal photochemical efficiency suggests that this species seems to tolerate Pb and Cd and hence, it is a suitable candidate for phytoremediation.
•Effects of Cd and Pb on uptake and photochemistry were studied in C. cardunculus.•Cd-treated plants showed ultrastructural injuries, but no decline in photochemistry.•Pb induced an increase of Hsp70 in root and a decrease of photochemistry.•The overall results suggest a higher sensitivity of C. cardunculus to Pb than Cd.
•Growth under red, blue and green light (RB, RGB) affects differently tomato and plane traits.•Plant biomass is reduced and photosynthesis stimulated in tomato under RB and RGB.•Photosynthesis of ...oriental plane was insensitive to different light qualities.•RB and RGB reduce isoprene emission by plane and change monoterpene blend in tomato.
The effect of different light qualities on growth, photosynthesis, leaf anatomy and isoprenoid emission was studied in two different fast-growing plant systems: a herbaceous crop, tomato (Solanum lycopersicum L.), and a tree, oriental plane (Platanus orientalis L.). Both plant species were subjected to three different light quality regimes: RGB (Red 33%, Green 33%, Blue 33%) and RB (Red 66%, Blue 33%), provided by light emitting diodes (LED); and white light (WL), considered as a control and provided by white fluorescent lamps. Compared to WL, RGB and RB reduced plant height, plant biomass and leaf area. The CO2 assimilation rate (A) was lower in tomato grown under WL than RGB and RB, while A was similar in oriental plane leaves exposed to the three light regimes. In tomato, stomatal (gs) and mesophyll (gm) conductance were higher under RGB and RB compared to WL. In plane, gs was also higher under RGB and RB, while gm was not significantly influenced by different light qualities. In both species, leaf lamina thickness (LT) and stomata size were the anatomical traits most affected by the different light regimes. In tomato, leaf lamina thickness was significantly reduced in RGB and RB leaves, whereas in oriental plane leaf lamina thickness was significantly higher in RGB and RB than in WL leaves. In both species, RB leaves showed bigger stomata size than WL and RGB leaves. Light quality also affected photosynthesis-dependent volatile isoprenoids. In tomato, β-phellandrene was lower under RB and RGB compared to WL. However, RGB and RB stimulated α-pinene, carene and α-terpinene emissions. Oriental plane released about 14nmolm−2s−1 isoprene when growing at WL, while the emission was reduced under RGB and even more under RB. In summary, photosynthetic performance, leaf anatomy, biomass production, and volatile isoprenoids are affected by light quality differently in tomato and plane plants. Light quality control may have important applications to modulate plant productivity and increase biosynthesis of useful biochemical compounds.
High concentrations of air pollutants have been linked to increased incidence of stroke in North America and Europe but not yet assessed in mainland China. The aim of this study is to evaluate the ...association between stroke hospitalization and short-term elevation of air pollutants in Wuhan, China.
Daily mean NO2, SO2 and PM10 levels, temperature and humidity were obtained from 2006 through 2008. Data on stroke hospitalizations (ICD 10: I60-I69) at four hospitals in Wuhan were obtained for the same period. A time-stratified case-crossover design was performed by season (April-September and October-March) to assess effects of pollutants on stroke hospital admissions.
Pollution levels were higher in October-March with averages of 136.1 µg/m(3) for PM10, 63.6 µg/m(3) for NO2 and 71.0 µg/m(3) for SO2 than in April-September when averages were 102.0 µg/m(3), 41.7 µg/m(3) and 41.7 µg/m(3), respectively (p<.001). During the cold season, every 10 µg/m(3) increase in NO2 was associated with a 2.9% (95%C.I. 1.2%-4.6%) increase in stroke admissions on the same day. Every 10 ug/m(3) increase in PM10 daily concentration was significantly associated with an approximate 1% (95% C.I. 0.1%-1.4%) increase in stroke hospitalization. A two-pollutant model indicated that NO2 was associated with stroke admissions when controlling for PM10. During the warm season, no significant associations were noted for any of the pollutants.
Exposure to NO2 is significantly associated with stroke hospitalizations during the cold season in Wuhan, China when pollution levels are 50% greater than in the warm season. Larger and multi-center studies in Chinese cities are warranted to validate our findings.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The causes of autism spectrum disorder (ASD) are not well known. Recent investigations have suggested that air pollution, including PM2.5, may play a role in the onset of this condition. The ...objective of the present work was to investigate the association between prenatal and early childhood exposure to fine particulate matter (PM2.5) and risk for childhood ASD. A population-based case-control study was conducted in children born between January 1, 2005 and December 31, 2009 in six counties in Southwestern Pennsylvania. ASD cases were recruited from specialty autism clinics, local pediatric practices, and school-based special needs services. ASD cases were children who scored 15 or above on the Social Communication Questionnaire (SCQ) and had written documentation of an ASD diagnosis. Controls were children without ASD recruited from a random sample of births from the Pennsylvania state birth registry and frequency matched to cases on birth year, gender, and race. A total of 217 cases and 226 controls were interviewed. A land use regression (LUR) model was used to create person- and time-specific PM2.5 estimates for individual (pre-pregnancy, trimesters one through three, pregnancy, years one and two of life) and cumulative (starting from pre-pregnancy) key developmental time periods. Logistic regression was used to investigate the association between estimated exposure to PM2.5 during key developmental time periods and risk of ASD, adjusting for mother's age, education, race, and smoking. Adjusted odds ratios (AOR) were elevated for specific pregnancy and postnatal intervals (pre-pregnancy, pregnancy, and year one), and postnatal year two was significant, (AOR=1.45, 95% CI=1.01–2.08). We also examined the effect of cumulative pregnancy periods; noting that starting with pre-pregnancy through pregnancy, the adjusted odds ratios are in the 1.46–1.51 range and significant for pre-pregnancy through year 2 (OR=1.51, 95% CI=1.01–2.26). Our data indicate that both prenatal and postnatal exposures to PM2.5 are associated with increased risk of ASD. Future research should include multiple pollutant models and the elucidation of the biological mechanism for PM2.5 and ASD.
•A case-control study of childhood autism and PM2.5 air pollution was conducted.•Daily PM2.5 was linked to residences of cases and controls prenatally to age two.•There was increased risk for childhood autism (OR=1.51, 95% CI=1.01–2.26).•Prenatal and postnatal exposure to PM2.5 is associated with increased risk of ASD
In many crops, including grapevine, the distribution of reflecting dust on foliage is a practice potentially leading to the mitigation of environmental stresses such as excessive light and limited ...water supply. This study aimed to evaluate whether the presence of dust on the leaves may affect PSII photochemical efficiency and gas-exchange measurements, thus leading to biased results. The study was conducted in a winery located at Benevento (Italy) on Vitis vinifera L. subsp. vinifera 'Falanghina' where the application of basalt dust was tested on the canopy to alleviate the effects of water stress. The results showed that there is no difference in PSII photochemistry or gas-exchange parameters measured in the presence of dust or after cleaning the leaves. Therefore, we conclude there is no need to remove dust from leaves before performing the ecophysiological investigations, thus fastening and simplifying the data collection.
In this work, the effects of light quality and beneficial microbes (biofertilizer) supply on structural and ecophysiological traits of spinach were investigated. Plants were grown under four light ...quality regimens: white light (WL), red-blue (RB), red-green (RG), and red (R) light, with or without the addition of biofertilizer. RG and R plants without biofertilizer showed morphological traits typical of shaded plants as wide leaf lamina and high photosynthetic pigment content. These plants also exhibited a higher photosynthetic capacity compared to WL and RB plants. The improved photosynthesis in RG plants was due to both morphological and physiological adjustments allowing a better utilisation of light energy, whereas in R plants it has been attributed to a reduced photorespiration rate. Biofertilizer application under WL improved plant performance enhancing photosynthesis. The high carbon gain compensates the costs of symbiosis. Biofertilizer application under R light favouring too much the microbial root colonisation, removed the benefits of symbiosis. The interaction of light quality and biofertilization significantly affects the root-microbe relationship.
This work aimed to evaluate if chilling stress may be mitigated by elevated CO
2
(EC) in
Beta vulgaris
L. plants. Photosynthetic rate was measured at 21% and 2% O
2
after a short-term exposure of 5 h ...at four different treatments: 360 μmol(CO
2
) mol
–1
/25°C (AC); 360 μmol(CO
2
) mol
–1
/4°C (AC+LT); 700 μmol(CO
2
) mol
–1
/25°C (EC); 700 μmol(CO
2
) mol–1/4°C (EC+LT). Compared to AC+LT, EC+LT plants showed higher values of CO
2
fixation, photochemical activity, and Rubisco amount. These latter invest a higher portion of photosynthetic electron flow to O
2
, differently from AC+LT plants that promote the regulated thermal dissipation processes. In EC+LT plants, the photosynthetic electron flow to O
2
acts as a safety mechanism against the excess of absorbed light, upon return to prechilling conditions, allowing photosynthetic apparatus to maintain its efficiency. In AC+LT plants, the increase of thermal dissipation processes was not adequate to guarantee the PSII photoprotection and the photosynthetic recovery after chilling.
PDF
