Future climate warming is expected to enhance plant growth in temperate ecosystems and to increase carbon sequestration. But although severe regional heatwaves may become more frequent in a changing ...climate, their impact on terrestrial carbon cycling is unclear. Here we report measurements of ecosystem carbon dioxide fluxes, remotely sensed radiation absorbed by plants, and country-level crop yields taken during the European heatwave in 2003. We use a terrestrial biosphere simulation model to assess continental-scale changes in primary productivity during 2003, and their consequences for the net carbon balance. We estimate a 30 per cent reduction in gross primary productivity over Europe, which resulted in a strong anomalous net source of carbon dioxide (0.5 Pg C yr-1) to the atmosphere and reversed the effect of four years of net ecosystem carbon sequestration. Our results suggest that productivity reduction in eastern and western Europe can be explained by rainfall deficit and extreme summer heat, respectively. We also find that ecosystem respiration decreased together with gross primary productivity, rather than accelerating with the temperature rise. Model results, corroborated by historical records of crop yields, suggest that such a reduction in Europe's primary productivity is unprecedented during the last century. An increase in future drought events could turn temperate ecosystems into carbon sources, contributing to positive carbon-climate feedbacks already anticipated in the tropics and at high latitudes.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The temperature sensitivity of soil respiration (SR) is often estimated from the seasonal changes in the flux relative to those in soil temperature, and subsequently used in models to interpolate or ...predict soil fluxes. However, temperature sensitivities derived from seasonal changes in SR (from here on denoted seasonal Q10) may not solely reflect the temperature sensitivity of SR, because seasonal changes in SR can also be affected by other seasonally fluctuating conditions and processes. In this manuscript, we present a case study of how the seasonal Q10 of SR can be decoupled from the temperature sensitivity of SR. In a mixed temperate forest, we measured SR under vegetations with different leaf strategies: pure evergreen, pure deciduous, and mixed. Seasonal Q10 was much higher under deciduous than under evergreen canopies. However, at a shorter time scale, both vegetation types exhibited very similar Q10 values, indicating that the large differences in seasonal Q10 do not represent differences in the temperature sensitivity of the soil metabolism. The seasonal Q10 depends strongly on the amplitude of the seasonal changes in SR (SRs), which, under the particular climatic and edaphic conditions of our forest study site, were significantly larger in deciduous forest. In turn, SRs was positively correlated with the seasonal changes in leaf area index (LAIs), a measure of the deciduousness of the vegetation. Thus, in this temperate maritime forest, seasonal Q10 of SR was strongly influenced by the deciduousness of the vegetation. We conclude that the large differences in seasonal Q10 were not entirely due to different temperature sensitivities, but also to different seasonal patterns of plant activity in the evergreen and deciduous plants of this site. Some coniferous forests may be more seasonal than the one we studied, and the deciduous–evergreen differences observed here may not be broadly applicable, but this case study demonstrates that variation of plant phenological process can significantly contribute to the seasonality of SR, and, hence, calculated Q10 values. Where this occurs, the seasonal Q10 value for SR does not accurately represent temperature sensitivity. Because the strong seasonal correlation between SR and temperature does not necessarily imply a causal relationship, Q10 values derived form annual patterns of SR should be used with caution when predicting future responses of SR to climatic change.
Objective
This study evaluated the effect of non-surgical periodontal therapy (NSPT) on the cytokine profile in gingival crevicular fluid (GCF) in patients with breast cancer and periodontitis.
...Methods
Forty patients were allocated into the periodontitis group (P) (
n
= 20) and breast cancer with periodontitis group (BC/P) (
n
= 20). Two days before the removal of infectious foci from the oral cavity and NSPT, as well as periodontal reevaluations, C-reactive protein, neutrophils (10
3
μL), and platelets (10
3
μL), were evaluated. The following cytokines in GCF, interleukin (IL)-4, IL-10, IL-2, IL-6, IL-1β, tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), and transforming growth factor-β (TGF-β) were evaluated by the Luminex assay at baseline, and 45 and 180 days after therapy. Cytokine levels were analyzed for correlations with the clinical parameters: clinical attachment level (CAL), probing depth (PD), bleeding on probing (BOP), and plaque index (PI).
Results
After NSPT, IL-2, TNF-α, and TGF-β were downregulated (
p
<0.05) in the BC/P. In the P group, INF-γ, IL-2, and TNF-α were downregulated (
p
<0.05), and TGF-β was increased (
p
<0.05). At 180 days, IL-6 in GCF was significantly positively correlated with PD and CAL (
r
=0.45,
r
=0.56) in the BC/P (
p
<0.05). In the P group, IL-1β in GCF was positively correlated with PD and CAL (
r
=0.56,
r
=0.59) at 45 days (
p
<0.05).
Conclusion
NSPT, before the start of chemotherapy, helps to reduce the inflammatory markers associated with the activity of periodontal disease, favoring a less inflammatory pattern, to avoid the exacerbation of periodontitis.
This study investigates the performances of different optical indices to estimate gross primary production (GPP) of herbaceous stratum in a Mediterranean savanna with different nitrogen (N) and ...phosphorous (P) availability. Sun-induced chlorophyll fluorescence yield computed at 760 nm (Fy760), scaled photochemical reflectance index (sPRI), MERIS terrestrial-chlorophyll index (MTCI) and normalized difference vegetation index (NDVI) were computed from near-surface field spectroscopy measurements collected using high spectral resolution spectrometers covering the visible near-infrared regions. GPP was measured using canopy chambers on the same locations sampled by the spectrometers. We tested whether light-use efficiency (LUE) models driven by remote-sensing quantities (RSMs) can better track changes in GPP caused by nutrient supplies compared to those driven exclusively by meteorological data (MM). Particularly, we compared the performances of different RSM formulations – relying on the use of Fy760 or sPRI as a proxy for LUE and NDVI or MTCI as a fraction of absorbed photosynthetically active radiation (fAPAR) – with those of classical MM. Results showed higher GPP in the N-fertilized experimental plots during the growing period. These differences in GPP disappeared in the drying period when senescence effects masked out potential differences due to plant N content. Consequently, although MTCI was closely related to the mean of plant N content across treatments (r2 = 0.86, p < 0.01), it was poorly related to GPP (r2 = 0.45, p < 0.05). On the contrary sPRI and Fy760 correlated well with GPP during the whole measurement period. Results revealed that the relationship between GPP and Fy760 is not unique across treatments, but it is affected by N availability. Results from a cross-validation analysis showed that MM (AICcv = 127, MEcv = 0.879) outperformed RSM (AICcv =140, MEcv = 0.8737) when soil moisture was used to constrain the seasonal dynamic of LUE. However, residual analyses demonstrated that GPP predictions with MM are inaccurate whenever no climatic variable explicitly reveals nutrient-related changes in the LUE parameter. These results suggest that RSM is a valuable means to diagnose nutrient-induced effects on the photosynthetic activity.
The present work aims to investigate the microstructure evolution along the length of a directionally solidified Al–8wt.%Ni hypereutectic alloy with a view to tailoring the range of microstructural ...parameters providing the best balance among tensile, wear, and corrosion properties. A macrostructure columnar region is shown to be associated with solidification cooling rates (
T
˙
) > 4.8 °C/s, having a microstructure typified by eutectic colonies (EC) of Al
3
Ni fibers + α-Al matrix. Differently, for
T
˙
< 4.8 °C/s, equiaxed grains prevailed consisting of the primary Al
3
Ni phase distributed in the EC matrix boundaries. A single diagram is proposed to relate experimental values of tensile, wear, and corrosion properties to each kind of microstructure (EC and Al
3
Ni + EC), exhibiting distinct behaviors, i.e., the Al–8wt.%Ni alloy with an EC microstructure is shown to provide higher tensile and wear resistances, whereas the best corrosion resistance and medium wear resistance can be assigned to the Al–8wt.%Ni alloy with an Al
3
Ni + EC microstructure.
Introduction
Surgical treatment of diastasis recti is still a matter of debate. Open approaches such as abdominoplasty, which offer the possibility to combine reparation of the diastasis with ...abdominal cosmetic surgery, are challenged by the emerging less-invasive laparoscopic or robotic techniques that offer shorter recovery for patients. However, evidence in favour of one of the two approaches concerning both short- and long-term complications and functional results is still lacking. In this paper, we analysed clinical and functional results of a new endo-laparoscopic technique for midline reconstruction (THT technique) in patients with primary abdominal wall defects associated with diastasis recti.
Methods
Prospective observational study on 110 consecutive patients was submitted to endo-laparoscopic reconstruction of the abdominal wall with linear staplers. Morbidity and relapse rates with clinical and radiological follow-up were recorded at 1, 6, 12, and 24 months after the operation. Data regarding the impact of surgery on patients’ quality of life (EuraHSQol) on chronic low back pain (Oswestry Disability Index, ODI) and urinary stress incontinence (Incontinence Severity Index, ISI) were gathered.
Results
After a mean follow-up of 14 months, the morbidity rate was 9.1% and no recurrences were recorded. 6-month follow-up ultrasound showed a rectus muscles mean distance of 6.7 mm; EuraHSQol, ODI, and ISI scores significantly improved in 93%, 77%, and 63% of the cases, respectively.
Conclusions
The THT technique proved to be a feasible, safe, and effective alternative for corrective surgery of primary midline hernias associated with diastasis recti. Short- and mid-term results are encouraging but need to be confirmed by further studies with longer follow-up. The achieved midline reconstruction offers a significant improvement of patients' perceived quality of life through reduction of abdominal wall pain, bulging, low back pain, and urinary stress incontinence.
In recent years, growing population and expansion of settlements and life-lines over hazardous areas have largely increased the impact of natural disasters both in industrialized and developing ...countries. Third world countries have difficulty meeting the high costs of controlling natural hazards through major engineering works and rational land-use planning. Industrialized societies are increasingly reluctant to invest money in structural measures that can reduce natural risks. Hence, the new issue is to implement warning systems and land utilization regulations aimed at minimizing the loss of lives and property without investing in long-term, costly projects of ground stabilization. Government and research institutions worldwide have long attempted to assess landslide hazard and risks and to portray its spatial distribution in maps. Several different methods for assessing landslide hazard were proposed or implemented. The reliability of these maps and the criteria behind these hazard evaluations are ill-formalized or poorly documented. Geomorphological information remains largely descriptive and subjective. It is, hence, somewhat unsuitable to engineers, policy-makers or developers when planning land resources and mitigating the effects of geological hazards. In the Umbria and Marche Regions of Central Italy, attempts at testing the proficiency and limitations of multivariate statistical techniques and of different methodologies for dividing the territory into suitable areas for landslide hazard assessment have been completed, or are in progress, at various scales. These experiments showed that, despite the operational and conceptual limitations, landslide hazard assessment may indeed constitute a suitable, cost-effective aid to land-use planning. Within this framework, engineering geomorphology may play a renewed role in assessing areas at high landslide hazard, and helping mitigate the associated risk.
High solidification cooling rates during unsteady-state conditions of solidification of Al-based alloys can induce different microstructural length scales or metastable phases, leading to improved ...properties. The present study aims to characterize the microstructural arrangement of the hypereutectic Al–8 wt%Ni alloy, unidirectionally solidified in unsteady-state heat flow conditions, examining the influence of the cooling rate in the development of the Al–Al
3
Ni eutectic and the primary phase. A columnar-to-equiaxed macrostructural transition is shown to occur at a solidification cooling rate (
Ṫ
) of about 4.8 °C/s, with different microstructures associated with each morphological zone. The observation of microstructures of hypoeutectic, eutectic and hypereutectic Al–Ni alloys, has permitted an asymmetric coupled zone diagram to be proposed. The microstructural interphase spacings of the Al–8 wt%Ni alloy are experimentally determined and correlated to
Ṫ
, and the Vickers microhardness (HV) is shown to decrease with the increase in such spacings. The higher experimental HV profile of the examined hypereutectic alloy as compared to that of the eutectic Al–Ni alloy is attributed to the formation of a supersaturated solid solution of Ni in
α
-Al.
Purpose
Despite the recent growing interest of the scientific community, there is still no consensus on the actual applicability and effectiveness of sentinel lymph node (SL) procedure in colon ...cancers. This study aims to quantify feasibility, detection rate, negative predictive value, and accuracy of the SL identified with fluorescent dye in early colon cancers (ECC).
Methods
This study conducted a consecutive sampling of 95 patients with non-metastatic colorectal cancer who have been treated with laparoscopic colon resection and complete mesocolic excision after a 25-mg indocyanine green peritumoral laparoscopic injection and SL identification with a near-infrared camera. The SL was later isolated and sent to ultra-staging.
Results
Ninety-five patients with an average age of 71 (range 37–90) and a mean BMI of 25 (range 18–39) have been recruited. On the patient sample (92 Pts), an average of 1.49 SL (range 1–5) and a mean time of 4 min were identified. The detection rate was 96.8% and the negative predictive value and accuracy rates were 96.2% and 93.4%, respectively.
Conclusions
Mapping the SL with fluorescent dye can play an important role in the treatment of colon cancers, particularly those at early stages, and can lead to ultra-conservative surgery.
▶
▪. ▶ This data-oriented approach from European cropland showed average carbon loss of 95
±
87
g
C
m
−2
y
−1. ▶ The full GHG balance of the considered sites was estimated to be 160
g
C
m
−2
y
−1 in ...CO
2-equivalents. ▶ Carbon losses are mainly related to soils with high carbon concentrations which are not in equilibrium.
Data sets of biometeorological measurements of ecosystem CO
2 flux, combined with harvest and manure data from several European cropland were integrated to provide an assessment of the carbon budget. Sites encompassed different climatic regions and contrasting crop rotations. The influence of different crops and management practices was also assessed to identify some of the major factors contributing to the cropland carbon balance. Since crops are rotated and cropping periods do not always follow the calendar year, net ecosystem production (NEP) as well as net biome production (NBP) sums of full crop rotations or of at least 4 years of longer-term crop rotations and of monocultures were used. In a second analysis NBP sums were correlated to soil properties. Finally, the data were combined with additional data to derive a mean annual GHG balance for the European cropland sites under consideration.
Five crop rotations and two monocultures were integrated over 4 years. During 4 years the average annual NEP was −240
±
113
g
C
m
−2
y
−1. On average, 382
±
117
g
C
m
−2
y
−1 were harvested, where as average carbon inputs by manure and seeding was 47
±
51
g
C
m
−2 y
−1. The average NBP of the seven sites under consideration was estimated to be a carbon loss of 95
±
87
g
C
m
−2
y
−1. The full GHG balance of the considered sites was estimated to be 160
g
C
m
−2
y
−1 in CO
2-equivalents.
These results challenge current good practice guidelines that predict neutral carbon budgets for systems where the inputs of manure and crop residues are of comparable magnitude to those associated with the sites examined in this study. Ongoing humus loss in spite of good practice is mainly related to soils with high carbon concentrations which are not in equilibrium but may also be a result of already ongoing climate change. A modification in the good practice guidelines to increase carbon inputs may be required.
Results from a representativeness analysis suggest that more than 50 sites are necessary for a European cropland flux network to adequately represent the variability of climate, soil and management within the European continent. Thus, the uncertainties due to the network design are currently bigger than the uncertainty intrinsic in the measurement method.
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