Forest production efficiency increases with growth temperature.

Forest production efficiency (FPE) metric describes how efficiently the assimilated carbon is partitioned into plants organs (biomass production, BP) or-more generally-for the production of organic matter (net primary production, NPP). We present a global analysis of the relationship of FPE to stand-age and climate, based on a large compilation of data on gross primary production and either BP or NPP. FPE is important for both forest production and atmospheric carbon dioxide uptake. We find that FPE increases with absolute latitude, precipitation and (all else equal) with temperature. Earlier findings-FPE declining with age-are also supported by this analysis. However, the temperature effect is opposite to what would be expected based on the short-term physiological response of respiration rates to temperature, implying a top-down regulation of carbon loss, perhaps reflecting the higher carbon costs of nutrient acquisition in colder climates. Current ecosystem models do not reproduce this phenomenon. They consistently predict lower FPE in warmer climates, and are therefore likely to overestimate carbon losses in a warming climate.

Assessment of climate change effects on mountain ecosystems through a cross-site analysis in the Alps and Apennines.

Mountain ecosystems are sensitive and reliable indicators of climate change. Long-term studies may be extremely useful in assessing the responses of high-elevation ecosystems to climate change and other anthropogenic drivers from a broad ecological perspective. Mountain research sites within the LTER (Long-Term Ecological Research) network are representative of various types of ecosystems and span a wide bioclimatic and elevational range. Here, we present a synthesis and a review of the main results from ecological studies in mountain ecosystems at 20 LTER sites in Italy, Switzerland and Austria covering in most cases more than two decades of observations. We analyzed a set of key climate parameters, such as temperature and snow cover duration, in relation to vascular plant species composition, plant traits, abundance patterns, pedoclimate, nutrient dynamics in soils and water, phenology and composition of freshwater biota. The overall results highlight the rapid response of mountain ecosystems to climate change, with site-specific characteristics and rates. As temperatures increased, vegetation cover in alpine and subalpine summits increased as well. Years with limited snow cover duration caused an increase in soil temperature and microbial biomass during the growing season. Effects on freshwater ecosystems were also observed, in terms of increases in solutes, decreases in nitrates and changes in plankton phenology and benthos communities. This work highlights the importance of comparing and integrating long-term ecological data collected in different ecosystems for a more comprehensive overview of the ecological effects of climate change. Nevertheless, there is a need for (i) adopting co-located monitoring site networks to improve our ability to obtain sound results from cross-site analysis, (ii) carrying out further studies, in particular short-term analyses with fine spatial and temporal resolutions to improve our understanding of responses to extreme events, and (iii) increasing comparability and standardizing protocols across networks to distinguish local patterns from global patterns.

Are optical indices good proxies of seasonal changes in carbon fluxes and stress-related physiological status in a beech forest?

This study investigates the functionality of a Mediterranean-mountain beech forest in Central Italy using simultaneous determinations of optical measurements, carbon (C) fluxes, leaf eco-physiological and biochemical traits during two growing seasons (2014-2015). Meteorological variables showed significant differences between the two growing seasons, highlighting a heat stress coupled with a reduced water availability in mid-summer 2015. As a result, a different C sink capacity of the forest was observed between the two years of study, due to the differences in stressful conditions and the related plant physiological status. Spectral indices related to vegetation (VIs, classified in structural, chlorophyll and carotenoid indices) were computed at top canopy level and used to track CO2 fluxes and physiological changes. Optical indices related to structure (EVI 2, RDVI, DVI and MCARI 1) were found to better track Net Ecosystem Exchange (NEE) variations for 2014, while indices related to chlorophylls (SR red edge, CL red edge, MTCI and DR) provided better results for 2015. This suggests that when environmental conditions are not limiting for forest sink capacity, structural parameters are more strictly connected to C uptake, while under stress conditions indices related to functional features (e.g., chlorophyll content) become more relevant. Chlorophyll indices calculated with red edge bands (SR red edge, NDVI red edge, DR, CL red edge) resulted to be highly correlated with leaf nitrogen content (R2>0.70), while weaker, although significant, correlations were found with chlorophyll content. Carotenoid indices (PRI and PSRI) were strongly correlated with both chlorophylls and carotenoids content, suggesting that these indices are good proxies of the shifting pigment composition related to changes in soil moisture, heat stress and senescence. Our work suggests the importance of integrating different methods as a successful approach to understand how changing climatic conditions in the Mediterranean mountain region will impact on forest conditions and functionality.

Atmospheric deposition, CO2, and change in the land carbon sink.

Concentrations of atmospheric carbon dioxide (CO2) have continued to increase whereas atmospheric deposition of sulphur and nitrogen has declined in Europe and the USA during recent decades. Using time series of flux observations from 23 forests distributed throughout Europe and the USA, and generalised mixed models, we found that forest-level net ecosystem production and gross primary production have increased by 1% annually from 1995 to 2011. Statistical models indicated that increasing atmospheric CO2 was the most important factor driving the increasing strength of carbon sinks in these forests. We also found that the reduction of sulphur deposition in Europe and the USA lead to higher recovery in ecosystem respiration than in gross primary production, thus limiting the increase of carbon sequestration. By contrast, trends in climate and nitrogen deposition did not significantly contribute to changing carbon fluxes during the studied period. Our findings support the hypothesis of a general CO2-fertilization effect on vegetation growth and suggest that, so far unknown, sulphur deposition plays a significant role in the carbon balance of forests in industrialized regions. Our results show the need to include the effects of changing atmospheric composition, beyond CO2, to assess future dynamics of carbon-climate feedbacks not currently considered in earth system/climate modelling.

A randomised controlled trial of the effectiveness of a program for early detection and treatment of depression in primary care.

OBJECTIVE: There is considerable uncertainty about whether depression screening programs in primary care may improve outcomes and what specific features of such programs may contribute to success. We tested the effectiveness of a program involving substantial commitment from local mental health services. METHODS: Prospective, randomised, patient- and evaluator-masked, parallel-group, controlled study. Participants were recruited in several urban primary care practices where they completed the PC-SAD screener and WHOQOL-Bref. Those who screened positive and did not report suicidal ideation (N=115) were randomised to an intervention group (communication of the result and offer of psychiatric evaluation and treatment free of charge; N=56) or a control group (no feedback on test result for 3 months; N=59). After 3 months, 100 patients agreed to a follow-up telephone interview including the administration of the PC-SAD5 and WHOQOL-Bref. RESULTS: Depression severity and quality of life improved significantly in both groups. Intent-to-treat analysis showed no effect of the intervention. As only 37% of patients randomised to the intervention group actually contacted the study outpatient clinic, we performed a per-protocol analysis to determine whether the intervention, if delivered as planned, had been effective. This analysis revealed a significant positive effect of the intervention on severity of depressive symptoms, and on response and remission rate. Complier average causal effect analysis yielded similar results. CONCLUSION: Due to the relatively small sample size, our findings should be regarded as preliminary and have limited generalizability. They suggest that there are considerable barriers on the part of many patients to the implementation of depression screening programs in primary care. While such programs can be effective, they should be designed based on the understanding of patients' perspectives.

Diagnostic Accuracy of the Primary Care Screener for Affective Disorder (PC-SAD) in Primary Care.

BACKGROUND: Depression goes often unrecognised and untreated in non-psychiatric medical settings. Screening has recently gained acceptance as a first step towards improving depression recognition and management. The Primary Care Screener for Affective Disorders (PC-SAD) is a self-administered questionnaire to screen for Major Depressive Disorder (MDD) and Dysthymic Disorder (Dys) which has a sophisticated scoring algorithm that confers several advantages. This study tested its performance against a 'gold standard' diagnostic interview in primary care. METHODS: A total of 416 adults attending 13 urban general internal medicine primary care practices completed the PC-SAD. Of 409 who returned a valid PC-SAD, all those scoring positive (N=151) and a random sample (N=106) of those scoring negative were selected for a 3-month telephone follow-up assessment including the administration of the Structured Clinical Interview for DSM-IV-TR Axis I Disorders (SCID-I) by a psychiatrist who was masked to PC-SAD results. RESULTS: Most selected patients (N=212) took part in the follow-up assessment. After adjustment for partial verification bias the sensitivity, specificity, positive and negative predictive value for MDD were 90%, 83%, 51%, and 98%. For Dys, the corresponding figures were 78%, 79%, 8%, and 88%. CONCLUSIONS: While some study limitations suggest caution in interpreting our results, this study corroborated the diagnostic validity of the PC-SAD, although the low PPV may limit its usefulness with regard to Dys. Given its good psychometric properties and the short average administration time, the PC-SAD might be the screening instrument of choice in settings where the technology for computer automated scoring is available.

Development and preliminary validation of the PC-SAD5, a screener-derived short depression severity measure.

BACKGROUND: The prevalence of depressive disorders is high among patients with skin disease. The PC-SAD is a 37-item self-administered depression screening questionnaire that has been validated in dermatological patients. OBJECTIVE: The aim of this study was to develop and validate a brief depression severity instrument derived from the PC-SAD that can be used to assess severity and monitor ongoing clinical course. METHODS: Two patient samples participated in the study: 72 adult dermatological inpatients and 73 adults attending six primary care practices. Psychiatric assessment included the Structured Clinical Interview for DSM-IV and an 18-item version of the PC-SAD; moreover, dermatological patients completed the Patient Health Questionnaire depression scale (PHQ-9), while primary care patients were administered the Montgomery-Asberg Depression Rating Scale (MADRS). A subset of five PC-SAD items showing the best psychometric properties were selected, and the reliability and validity of the resulting instrument (PC-SAD5) were examined. RESULTS: The PC-SAD5 showed satisfactory internal consistency in both samples. There was a high correlation between PC-SAD5 and PHQ-9 and MADRS scores. Multiple regression analysis revealed a gradient of PC-SAD5 scores from patients with no mental disorder, those with milder forms of depression, to those with Major Depressive Disorder. Similar results were observed for the 18-item version of the PC-SAD. CONCLUSION: The availability of valid and reliable continuous measures of depression severity derived from the PC-SAD extends its field of application from depression screening to use as a follow-up measure of depression severity in routine clinical practice. A validated very short instrument such as the PC-SAD5 may have substantial clinical value.

Europe-wide reduction in primary productivity caused by the heat and drought in 2003.

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.

Study of the field around magnetic force microscopy probes using electron holography.

We have used electron holography to perform quantitative investigations of the leakage flux of thin film tips used as probes in magnetic force microscopy. A method to deduce an arrangement of magnetic domains in a thin magnetic whisker from the knowledge of the stray flux is also described. A simple analytical model of the magnetic properties of the probes allows the extraction of computer images, which simulate the experimental results satisfactory. The reliability of the recorded experimental maps of the magnetic flux arising from these kinds of sensors allows an evaluation of the total flux affecting the sample and the calculation of the magnetic field profile along the tip axis.

[Prevalence of occupational allergy to laboratory animals in two towns of northern and central Italy]. / Prevalenza dell'allergia professionale agli animali di laboratorio in due città del nord e del centro Italia.

BACKGROUND: Laboratory animal allergy (LAA) is a well known occupational hazard for workers employed in biological and medical research institutes, but few Italian data on this disease exist. OBJECTIVES: The aim of our study was to evaluate the prevalence of LAA in 45 workers in Trieste (NE-Italy) and in 80 workers in Perugia (Central Italy) and to assess factors predisposing to sensitisation among subjects occupationally exposed to animals. METHODS: All subjects underwent a physical examination and responded to a standardized questionnaire for the evaluation of allergic respiratory symptoms and exposure data. Skin prick tests with common allergens and with hair extract from laboratory animals were performed and specific IgE was measured. Atopy was defined as positive skin prick test to common allergens. RESULTS: There were 60% atopic subjects in Trieste and 55% in Perugia and sensitisation to laboratory animal hair was found in 24.4% subjects in Trieste and in 35% in Perugia. The prevalence rates of LLA were respectively 11.1% and 11.2%; 2.3% and 3.7% complained of asthma while 8.9% and 7.5% complained of rhinitis. The resulting symptoms were significantly related to skin prick tests that were positive to laboratory animal hair (odds ratio (OR) = 7.64; 1.83-44.5), to skin prick test positivity to common inhalant allergens (OR = 5.29; 1.09-50.2), to common allergic symptoms (OR = 3.95; 1.05-18.2) and to exposure time exceeding 5 hours per day (OR = 5.45; 1.31-22.0). CONCLUSION: The role of atopy and of exposure time in causing LLA was confirmed and the need of prevention measures to reduce exposure in people at risk was discussed.

Organic pollution in a Ramsar site (Piallassa Baiona, northern Adriatic Sea).

A core collected in the Piallassa Baiona lagoon, a salt-marsh area already studied for Hg contamination related to nearby industrial sites, was analysed for organic micropollutants. Surface sediments show high concentrations of total PCBs (1148 ng g-1), PCDD/Fs (64 ng g-1) and PAHs (4801 ng g-1). According to a sedimentation rate of 0.4 cm y-1, the high increases in total PAH, PCB and PCDD/F concentrations began in the 1960s and peaked in the 1970s, in parallel with the highest Hg concentrations. Instead, the recent contamination, which primarily involves PCBs and PCDD/Fs, has been observed to be unrelated to Hg concentrations. Organic micropollutant concentrations in the sample core were compared with the sediment quality criteria provided by international guidelines, and revealed high toxic potential. This heavy contamination was also confirmed by comparison with similar environments, particularly the Lagoon of Venice. Further investigations are needed to understand better the sources of the recent contamination and to explain the different transfer pathways involved during sedimentation of the "old" material, dumped 20-30 years ago.

Downward fluxes of particulate carbon, nitrogen and phosphorus in the north-western Adriatic sea.

Downward fluxes of particles, organic carbon, total nitrogen and total phosphorus and the composition of the settled particulate matter were determined in the north-western Adriatic Sea at two coastal sites influenced by the outflows of the Po and Adige rivers and one offshore site. Vertical fluxes were strongly influenced by resuspension processes in addition to the primary flux and advection. The resuspended material contributed on average 34-43% of the total matter sedimented in the near bottom traps in coastal waters. Net annual vertical fluxes (due to primary flux and advection) of organic carbon, total nitrogen and phosphorus in the coastal stations were: 71-97 g C m(-2) year(-1), 8-14 g N m(-2) year(-1) and 2.1-2.3 g P m(-2) year(-1), with the highest values recorded at the station off the Po river delta. The offshore site was characterised by net annual fluxes of particulates, C, N and P approximately one order of magnitude lower than the above. The carbon export to the bottom was limited in the warm seasons when it constituted only 2-9% of primary production, due to high recycling and utilisation in the upper layer of the water column, increasing up to 8-18% in winter because of the instability of the water column and low biological utilisation.

Reported diagnosis of previous asthma in a sample of the Italian general population.

In this cross-sectional study we describe the prevalence and characteristics of subjects who self-reported a diagnosis of previous asthma in a sample of the Italian general population. We chose a wide age range (3-69 yrs) in order to obtain data over a large spectrum of the population. Interviews were conducted in 1,038 subjects by trained physicians using a modified version of the American Thoracic Society and National Heart & Lung Institute--Division of Lung Disease questionnaire proposed in 1978 (ATS-DLD-78). 791 subjects underwent skin prick tests for 7 common aeroallergens; 422 subjects underwent spirometry and 212 methacholine challenge tests. Cumulative prevalence of asthma was 7.9% (82/1038). Previous asthma (PA) was reported by 29 (35.4%) of the subjects, who said they had been but were no longer asthmatic; 65.5% of these claimed that PA had developed at or before the age of 14 yrs. No significant differences emerged in sex, age, family and personal history of atopy, and size of skin test reaction in subjects with PA compared to those with current asthma (CA). Although the difference was not statistically significant, the latter tended to be lifetime nonsmokers while subjects with PA were more often current smokers. Age at onset of asthma was significantly higher in subjects with CA than in subjects with PA (24.6 +/- 20 yrs vs. 12.0 +/- 15.0 yrs, p = 0.005). Bronchial hyperreactivity was present in 37.5% of subjects with PA, while forced expiratory volume in 1 sec (FEV1) was within normal limits in all. In conclusion, in this sample of the Italian population, PA was reported by about 1/3 of the asthmatic subjects, most of whom were atopic. Lung function was within normal limits in all, but bronchial hyperreactivity persisted in 1/3 subjects.

Reduction pneumoplasty versus respiratory rehabilitation in severe emphysema: a randomized study. Pulmonary Emphysema Research Group.

BACKGROUND: The purpose of the study was to determine in a prospective randomized trial the independent short-term physiologic impact of reduction pneumoplasty (RP) on respiratory rehabilitation (RR). METHODS: Sixty patients eligible for RP were randomly selected by computer to receive either RP (n = 30) or comprehensive RR (n = 30). Pulmonary function tests, analysis of blood gas levels, measurement of respiratory muscle strength (maximal inspiratory and expiratory pressures), 6-minute walk test (6MWT), and incremental treadmill test (ITT), were performed at baseline and at 3 and 6 months. RESULTS: Two treatment-related deaths occurred after RP and one after RR. At 6 months dyspnea index, maximal inspiratory pressure, 6MWT, ITT, and PaO2 were significantly improved in both groups whereas forced expiratory volume in 1 second and residual volume were significantly improved only in the surgical arm. In addition at 6 months, dyspnea index, 6MWT, maximal ITT, and PaO2 improved significantly more after RP than after RR. CONCLUSIONS: In our study short-term improvements in dyspnea index, oxygenation, inspiratory muscle strength, and exercise capacity occurred after either RP and RR. However dyspnea index, PaO2, and exercise capacity improved more after RP than after RR whereas pulmonary function improved only after RP.

Respiration as the main determinant of carbon balance in European forests.

Carbon exchange between the terrestrial biosphere and the atmosphere is one of the key processes that need to be assessed in the context of the Kyoto Protocol. Several studies suggest that the terrestrial biosphere is gaining carbon, but these estimates are obtained primarily by indirect methods, and the factors that control terrestrial carbon exchange, its magnitude and primary locations, are under debate. Here we present data of net ecosystem carbon exchange, collected between 1996 and 1998 from 15 European forests, which confirm that many European forest ecosystems act as carbon sinks. The annual carbon balances range from an uptake of 6.6 tonnes of carbon per hectare per year to a release of nearly 1 t C ha(-1) yr(-1), with a large variability between forests. The data show a significant increase of carbon uptake with decreasing latitude, whereas the gross primary production seems to be largely independent of latitude. Our observations indicate that, in general, ecosystem respiration determines net ecosystem carbon exchange. Also, for an accurate assessment of the carbon balance in a particular forest ecosystem, remote sensing of the normalized difference vegetation index or estimates based on forest inventories may not be sufficient.

Sediment composition and normalisation procedures: an example from a QUASH project sediment exercise.

The QUASH UE-Project was designed to assess the reliability of normalisation approaches to compensate the influence of natural process affecting the distribution and concentration of contaminants in sediment. The focus of this paper was to test the influence on normalisation procedures of an inorganic matrix using a sample collected in the Venice Lagoon, Italy.

Protection of intrinsic nerves of guinea-pig detrusor strips against anoxia/glucopenia and reperfusion injury by taurine.

There is ample evidence that ischaemia is associated with partial denervation of the detrusor muscle and that this is responsible for much of its abnormal contractile behaviour, resulting in bladder dysfunction (instability). In guinea-pig nerves are very susceptible to the ischaemic damage as compared to the muscle cells. The purpose of this study was to assess the neuroprotection afforded by taurine on guinea-pig detrusor under ischaemic-like conditions. Guinea-pig detrusor strips were subjected for 60 min to ischaemic-like conditions, followed by 150 min reperfusion. Intrinsic nerves underwent every 30 min electrical field stimulation (EFS) by 5-s trains of square voltage pulses of 0.05 ms duration (15 Hz, 50 V). Detrusor strips were perfused with 0.1, 1, 3 or 10 mM taurine during the ischaemia-like exposure and the first 30 min of reperfusion. Taurine (1 and 3 mM) significantly improved the response of the strips to EFS both at the end of ischaemia and reperfusion. On the contrary, neither 0.1 nor 10 mM taurine had significant effects. It is concluded that taurine can partially counteract the ischaemia-reperfusion injury in the guinea-pig urinary bladder.

Dermal exposure assessment of polycyclic aromatic hydrocarbons: in vitro percutaneous penetration from lubricating oil.

OBJECTIVES: Percutaneous penetration of polycyclic aromatic hydrocarbons (PAHs) is affected by various factors connected to exposure conditions. The nature of the matrix, such as that of oil, can strongly affect their percutaneous penetration. Risk assessment should consider these effects. We examined the effect of matrix on percutaneous penetration of PAHs, particularly that of lubricating oil. METHODS: The test apparatus consisted of an in vitro static diffusion cell system using full-thickness monkey (Cercopithecus aetiops) skin as the membrane and saline solution with gentamycin sulfate and 4% bovine serum albumin as receptor fluid. Chemical analysis of PAHs in the samples obtained from cells was carried out by inverse-phase HPCL, and the results were read by spectrofluorimetry. RESULTS: Comparing the penetration of 13 PAHs from a lubricating oil and from acetone solution with artificial sweat resulted in a significantly slower passage from the oil matrix for acenaphthene, anthracene, phenanthrene, fluoranthene, naphthalene, pyrene, fluorene (Mann-Whitney U test, P < 0.05). No significant differences in the passage were found for chrysene because, in the test with oil, its concentration was very often below the detection limit. For benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene it was possible to demonstrate a passage through the skin only when compounds were applied in acetone solution with artificial sweat. CONCLUSIONS: The results of the study suggest the necessity of dermal penetration data relevant for risk assessment, obtained under experimental conditions similar to the real exposure conditions.

Conformational stability of human erythrocyte transglutaminase. Patterns of thermal unfolding at acid and alkaline pH.

Tissue-type transglutaminase is irreversibly inactivated during heat treatment. The rate of inactivation is low at pH 7.5; it increases slightly at acid pH (6.1) but much more at alkaline pH (9.0-9.5), suggesting that specific effects take place in the alkaline range, possibly in relation to decreased stability of the transition-state intermediate as pH is raised above 9.0. Differential scanning calorimetry experiments indicate that thermal unfolding of the protein occurs with two separate transitions, involving independent regions of the enzyme. They are assigned to domains 1 and 2 and domains 3 and 4, respectively, by a combination of calorimetric and spectroscopic techniques. When considering the effects of pH, we noted that transglutaminase was unfolded via different pathways at the different pH values considered. At acid pH, the whole structure of the protein was lost irreversibly, with massive aggregation. At neutral and, even more so, at alkaline pH, aggregation was absent (or very limited at high protein concentration) and the loss of secondary structure was dependent on the ionization state of crucial lysine residues. Unfolding at pH 9.5 apparently chiefly involved the N-terminal region, as testified by changes in protein intrinsic fluorescence. In addition, the C-terminal region was destabilized at each pH value tested during thermal unfolding, as shown by digestion with V8 proteinase, which is inactive on the native protein. Evidence was obtained that the N-terminal and C-terminal regions interact with each other in determining the structure of the native protein.