123 research outputs found
Modeling high-resolution climate change impacts on wheat and maize in Italy
Abstract The Mediterranean basin has been identified as a prominent hotspot of climate change, with expected negative impacts on crop productivity, among others. Given the primary role that agriculture has to sustain cultural values, economic opportunities, and food security, it is crucial to identify specific risks in agriculture due to climate change, which can address more effective adaptation strategies and policies to cope with climate change. This study aims to evaluate the high-resolution impacts of climate change on the length of the growing cycle and yield of durum wheat, common wheat, and maize in Italy by using the CERES-Wheat and CERES-Maize crop models implemented in the Decision Support System for Agrotechnology Transfer (DSSAT) software. A digital platform (GIS-DSSAT) was developed to couple crop simulation models with dynamically downscaled climate projections at high resolution for Italy, which can better represent the Italian landscape complexity and the spatial distribution of different pedological and crop management features, providing more detailed information on the expected impacts on crops respect to previous studies at a coarser resolution. The projections have been extended for two climate change scenarios and accounting for uncertainty, either considering or not the potential direct effects of increasing atmospheric CO2 concentrations ([CO2]). Results show that climate change may affect Italian cereal production in the medium to long term periods. Maize is the main affected crop, with yield reductions homogeneously distributed from North to South Italy. Wheat yield is expected to decrease mainly in southern Italy, while northern Italy may benefit from higher precipitation regimes. Higher levels of atmospheric CO2 concentrations may partially offset the negative impact posed by climate change and increase the benefits in the northern regions, especially for common and durum wheat
Testicular cancer and sperm DNA damage: short- and long-term effects of antineoplastic treatment
The aim of this study was to investigate sperm DNA damage induced by chemo- and radiotherapy in patients with testicular cancer to provide data on the extent and persistence of nuclear damage that might affect individual reproductive potential. We evaluated pre- and post-antineoplastic treatment sperm DNA integrity, expressed as DNA Fragmentation Index (DFI), in a large caseload of testicular cancer patients by sperm chromatin structure assay. The mean total DFI for all patients at T0 was 18.0 ± 12.5%. Sperm chromatin profile was markedly impaired at T3 (27.7 ± 17.4%) and T6 (23.2 ± 15.3%), improving considerably at T12 and T24 (14.0 ± 8.9% and 14.4 ± 10.3%). After chemotherapy, we found a marked increase in DFI at T3 and T6 and a significant reduction at T12 and T24 in comparison with the baseline. In contrast, DFI increased at T3 and T6 after radiotherapy but the subsequent reduction was far less marked, reaching baseline values at T12 and T24. Finally, post-treatment DNA damage was not age or histotype dependent, but was more marked in the advanced stage of cancer. In this study, we showed that the chromatin profile may be affected in the months immediately following the end of the treatment, improving after 12-24 months. Our results thus indicate that post-treatment DNA damage is influenced both by the type and intensity of the therapy and by the pathological and clinical stage of the disease. © 2014 American Society of Andrology and European Academy of Andrology
Ricostruzione dei flussi di CO<sub>2</sub> di un ecosistema a macchia mediterranea mediante reti neurali
Nell’ultimo decennio sono state realizzate numerose reti di monitoraggio dei flussi di massa ed energia
a scala regionale, che utilizzano come standard di misura la tecnica dell’Eddy Covariance. La continuità del
monitoraggio dei flussi è una condizione difficilmente realizzabile a causa sia della complessità degli apparati di misura
sia di alcune limitazioni di carattere modellistico: in generale dopo i controlli di congruità fisica e biologica, non più del
65% dei dati risulta utilizzabile per la costruzione dei bilanci annuali. Negli ultimi anni sono state sviluppate
metodologie per la ricostruzione dei dati mancanti dei flussi di energia e materia negli ecosistemi terrestri; tuttavia,
attualmente non esiste una metodologia di ricostruzione standardizzata. In questo lavoro vengono realizzati modelli
basati sulle reti neurali per la ricostruzione dei flussi di CO2 in un ecosistema a macchia mediterranea; le prestazioni
fornite da tali modelli vengono confrontate con quelle di altre tecniche recentemente proposte dalla comunitÃ
internazionale. I dati sono stati raccolti nel corso del biennio 1998-99 in un sito sperimentale del progetto europeo
MEDEFLU situato nella Sardegna nord-occidentale. I modelli basati sulle reti neurali hanno fornito in genere
prestazioni superiori rispetto agli altri metodi, con valori dell’errore quadratico medio compresi tra 0.9 e 2.9 μmol m-2 s-
1 di CO2. Questi risultati confermano le possibilità applicative delle reti neurali nella ricostruzione dei flussi provenienti
da reti di monitoraggio
Effetti dell'anulazione del tronco nell'olivo (Ascolana tenera)
Effects of girdling with and without removal of a bark ring in «Ascolana tenera» olive-trees, whose charac
teristic is the variable yield, are reported in this study.
Girdling with and without removal of a bark ring, carried out before anthesis, increased the percentage of
setting of 40% the first one and of 70% the second one. The yield levels (resulted definitely low in control) resulted superior to 100% and 300%.
At the same time leaf diagnostic showed (between May and October) a decrease of leaf mineral composi
tion in leaves from girdled trees regarding N, Ca, Mg, P, Mg rates: in any case girdling with removal of a
bark ring showed more intense effects.
Considerable yield increases showed no bad influence on fruit morphology and quality
Important factors to model climate change effects on evapotranspiration
Although growers have considerable control over crop production, a major concern is the anticipated
increase in evapotranspiration (ET) due to global warming. ET rates, however, are also affected by
radiation, humidity, wind speed, crop morphology, and crop physiology in addition to temperature.
Crop ET (ETc) is commonly estimated as the product of reference ET (ET0) and a crop coefficient (Kc),
and the main factors affecting Kc values are net radiation, aerodynamic resistance, and canopy
resistance differences between the reference and crop surfaces. The standardized ET0 equation has
fixed values for the canopy resistance (rc), and different values are likely for other crops. The rc values
might also adjust with increasing CO2 and higher temperature. Aerodynamic resistance (ra) depends on
atmospheric stability, wind speed, and surface roughness. The relative aerodynamic contributions of
sensible heat to ET0 and ETc could change if the canopy development or the wind speed climatology
are modified by global warming. In this paper, we will discuss how the ET0 and Kc values vary with
microclimate and how Kc values and ET0 rates might react to global warming
Ecophysiological Responses to Rainfall Variability in Grassland and Forests Along a Latitudinal Gradient in Italy
In the Mediterranean region, ecosystems are severely affected by climate variability. The Italian Peninsula is a hot spot for biodiversity thanks to its heterogeneous landscape and the Mediterranean, Continental, and Alpine climates hosting a broad range of plant functional types along a limited latitudinal range from 40′ to 46′ N. In this study we applied a comparative approach integrating descriptive statistics, time series analysis, and multivariate techniques to answer the following questions: (i) do the climatic variables affect Gross Primary Productivity (GPP), Reco, Water Use Efficiency (WUE), and ET to a similar extent among different sites? (ii) Does a common response pattern exist among ecosystems along a latitudinal gradient in Italy? And, finally (iii) do these ecosystems respond synchronically to meteorological conditions or does a delayed response exist? Six sites along a latitudinal, altitudinal, and vegetational gradient from semi-arid (southern Italy), to a mountainous Mediterranean site (central Italy), and sub-humid wet Alpine sites (northern Italy) were considered. For each site, carbon and water fluxes, and meteorological data collected during two hydrologically-contrasting years (i.e., a dry and a wet year) were analyzed. Principal Component Analysis (PCA) was adopted to identify temporal and spatial variations in GPP, Ecosystem Respiration (Reco), WUE, and Evapotranspiration (ET). The model outlined differences among Mediterranean semi-arid, Mediterranean mountainous, and Alpine sites in response to contrasting precipitation regimes. GPP, Reco, WUE, and ET increased up to 16, 19, 25, and 28%, respectively in semi-arid Mediterranean sites and up to 15, 32, 15, and 11%, respectively in Alpine sites in the wet year compared to the dry year. Air temperature was revealed to be one of the most important variables affecting GPP, Reco, WUE, and ET in all the study sites. While relative air humidity was more important in southern Mediterranean sites, global radiation was more significant in northern Italy. Our work suggests that a realistic prediction of the main responses of Italian forests under climate change should also take in account delayed responses due to acclimation to abiotic stress or changing environmental conditions
Stima evapotraspirativa dei fabbisogni irrigui nelle principali aree agricole della Sardegna
ETP calculation for three important irriguous areas of Southern (39°17' N. I), Central (39°53' N. I) and Northern
(40°41' N. I) Sardinia through F.A.O. method shows too much high values with originai Blaney-Criddle
equation, reduced differences with Penman (original and F.A.O.) equation, Radiation method and B.-C. F.A.O.
equation respectively. The last method, believed the most suitable according to the first lisimetric measurements,
estimates annual mean ETP equal to 1194 mm, 1077 mm and 1022 mm for Southern, Central and
Northern Sardinia.
Effective rainfall successive analysis shows they are 50% of total rainfall (in case of grasses) and they hold
ETP for about 22%.
Therefore seasonal irrigation requirements, calculated through F.A.O. crop coefficients, are among 841 mm,
791 mm and 706 mm concerning grasses, and 353 mm, 322 mm and 311 mm concerning olive tree, for
Southern, Central and Northern Sardinia
Orientamenti per l'irrigazione del mirto
Preliminary observations on ecophysiology of Myrtus communis L. in cultural conditions
are reported. Responses of plants to different moisture soil conditions were observed using the
stem water potential methodology. Plants showed optimal ecophysiological behaviour under
moderate stress condition. Stress symptoms appear only with very low soil moisture content.
These first results show that this species requires only few water applications or regulated
deficit irrigation
Identification of membrane proteins regulated by ADAM15 by SUSPECS proteomics
ADAM15 is a member of the disintegrin-metalloproteinase family of sheddases, which plays a role in several biological processes including cartilage homeostasis. In contrast with well-characterized ADAMs, such as the canonical sheddases ADAM17 and ADAM10, little is known about substrates of ADAM15 or how the enzyme exerts its biological functions. Herein, we used surface-spanning enrichment with click-sugars (SUSPECS) proteomics to identify ADAM15 substrates and/or proteins regulated by the proteinase at the cell surface of chondrocyte-like cells. Silencing of ADAM15 by siRNAs significantly altered membrane levels of 13 proteins, all previously not known to be regulated by ADAM15. We used orthogonal techniques to validate ADAM15 effects on 3 of these proteins which have known roles in cartilage homeostasis. This confirmed that ADAM15-silencing increased cell surface levels of the programmed cell death 1 ligand 2 (PDCD1LG2) and reduced cell surface levels of vasorin and the sulfate transporter SLC26A2 through an unknown post-translational mechanism. The increase of PDCD1LG2 by ADAM15 knockdown, a single-pass type I transmembrane protein, suggested it could be a proteinase substrate. However, shed PDCD1LG2 could not be detected even by a data-independent acquisition mass spectrometry, a highly sensitive method for identification and quantification of proteins in complex protein samples, suggesting that ADAM15 regulates PDCD1LG2 membrane levels by a mechanism different from ectodomain shedding
Effects of warmer and drier climate conditions on plant composition and biomass production in a Mediterranean shrubland community
The last IPCC report predicts warmer and drier conditions for the future European climate and the
Mediterranean basin could be highly sensible to future climatic change. In order to investigate how the forecast
more stressing factors could affect Mediterranean shrubland ecosystems, an appropriate manipulation
of the microclimate was carried out in an area covered by Mediterranean maquis aimed at extending the
drought period and increasing the night-time temperature. Soil cover, plant growth, litterfall, leaf water
status, and leaf nutritional status were monitored over three growing seasons. The manipulation altered the
microclimate according to common scenarios, increasing mean annual night-time air temperature by about 1
°C and mean annual temperature by about 0.5 °C, and decreasing precipitation between 6-46% of the total
rainfall during the growing seasons. A general increase of vegetation cover was observed in the whole community
during the three years of experimentation. This positive temporal pattern was mainly observed in
control and warming treatment, whereas in the drought treatment it was less evident. At species-specific
level, a clear negative effect of drought treatment was observed for C. monspeliensis percentage cover. Shoot
elongation was not significantly affected by the warming treatment. A significant negative effect of drought
treatment was noticed in the 2001-2002 and 2002-2003 growing seasons. An increase of N and P concentrations
in the drought treatment in Cistus was observed and it can be explained by the reduced shoot growth
induced by the water shortage that we had observed in the same treatment. The absence of a concentration
effect on the other two species could be the signal of the different behaviour with regard to a drier climate,
and therefore could be a symptom of future change in species composition. We underline the need of longterm
observation, because of the different responses of plants in the short and long- term conditions
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