In the context of sustainable forest management and climate change, increasing tree richness has been proposed as a possible strategy to reach both ecological and productivity goals. This review ...focuses on the effects of mixed stands and increasing tree richness on soil fauna in temperate forests. Effects on earthworm and microarthropod (Collembola and Oribatid Mites) species diversity and abundance and community structure are examined, and clues to the main factors affecting soil communities in these stands are proposed.
Our statistical analyses showed no evidence of any general trend for the effect of mixture either on earthworm or microarthropod diversity or on their abundance. Indeed, positive, negative and non-significant effects have all been reported. Nevertheless, the majority of the studies did find that increased tree richness or the introduction of broad-leaves had a positive effect. In addition, our review shows that soil organism abundance and diversity can be strongly affected by the presence of certain tree species and that the soil organism community structure is, in most cases, significantly affected by an increase in tree richness or by a mixing effect. Litter features appear to be important drivers of soil fauna community composition, while mixture effect seems to have less impact on soil biota. Soil fauna are directly affected by the physical characteristics (microhabitats) and chemical composition (resource quality) of the litter specific to each tree species. Soil communities are then indirectly affected by the subsequent humus characteristics. We conclude our review with some guidelines for forest management and further research.
•Abundance and diversity of soil biota can be strongly affected by tree diversity.•A positive trend of increased tree diversity or when broad-leaves are introduced was found.•Soil community structure is systematically modified in mixed vs pure stands.•Tree species traits, rather than tree species richness, are the most important factor.
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Enabling the transport of fronthaul traffic in next-generation cellular networks fifth-generation (5G) following the cloud radio access network (C-RAN) architecture requires a redesign of the ...fronthaul network featuring high capacity and ultra-low latency. With the aim of leveraging statistical multiplexing gains, infrastructure reuse, and, ultimately, cost reduction, the research community is focusing on Ethernet-based packet-switch networks. To this end, we propose using the high queuing delay percen-tiles of the G/G/1 queuing model as the key metric in front-haul network dimensioning. Simulations reveal that Kingman's exponential law of congestion provides accurate estimates on such delays for the particular case of aggregating a number of evolved Common Public Radio Interface fronthaul flows, namely functional splits and II D . We conclude that conventional 10 G, 40 G, and 100 G transponders can cope with multiple legacy 10-20 MHz radio channels with worst-case delay guarantees. Conversely, scaling to 40 and 100 MHz channels will require the introduction of 200G, 400G, and even 1T high-speed transponders.
This review paper organizes and summarizes the literature on Vertical Greenery Systems (VGS) when used as passive tool for energy savings in buildings. First, with the information obtained in the ...reviewed literature some key aspects to consider when working with VGS are clarified, such as the classification systems, the climate influence, the plant species used and the different operating mechanisms. Then, the main conclusions of this literature, sorted by construction system (Green Walls or Green Façades) and climatic situation, are summarized. In general, it can be concluded that VGS provide great potential in reducing energy consumption in buildings, especially in the cooling periods. However, a lack of data on operation during the heating period as well as during the whole year has been found. On the other hand, results show that the investigations of VGS are not equally distributed around the world, being basically concentrated in Europe and Asia. Moreover, the review concludes that some aspects must be studied in depth, such as which species are the most suitable for each climate, influence on energy savings of the façade orientation, foliage thickness, presence of air layers, and finally, substrate layer composition and thickness in the case of green walls.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Background
The projected rise in the incidence of type 2 diabetes mellitus (T2DM) could develop into a substantial health problem worldwide. Whether diet, physical activity or both can prevent or ...delay T2DM and its associated complications in at‐risk people is unknown.
Objectives
To assess the effects of diet, physical activity or both on the prevention or delay of T2DM and its associated complications in people at increased risk of developing T2DM.
Search methods
This is an update of the Cochrane Review published in 2008. We searched the CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, ICTRP Search Portal and reference lists of systematic reviews, articles and health technology assessment reports. The date of the last search of all databases was January 2017. We continuously used a MEDLINE email alert service to identify newly published studies using the same search strategy as described for MEDLINE up to September 2017.
Selection criteria
We included randomised controlled trials (RCTs) with a duration of two years or more.
Data collection and analysis
We used standard Cochrane methodology for data collection and analysis. We assessed the overall quality of the evidence using GRADE.
Main results
We included 12 RCTs randomising 5238 people. One trial contributed 41% of all participants. The duration of the interventions varied from two to six years. We judged none of the included trials at low risk of bias for all 'Risk of bias' domains.
Eleven trials compared diet plus physical activity with standard or no treatment. Nine RCTs included participants with impaired glucose tolerance (IGT), one RCT included participants with IGT, impaired fasting blood glucose (IFG) or both, and one RCT included people with fasting glucose levels between 5.3 to 6.9 mmol/L. A total of 12 deaths occurred in 2049 participants in the diet plus physical activity groups compared with 10 in 2050 participants in the comparator groups (RR 1.12, 95% CI 0.50 to 2.50; 95% prediction interval 0.44 to 2.88; 4099 participants, 10 trials; very low‐quality evidence). The definition of T2DM incidence varied among the included trials. Altogether 315 of 2122 diet plus physical activity participants (14.8%) developed T2DM compared with 614 of 2389 comparator participants (25.7%) (RR 0.57, 95% CI 0.50 to 0.64; 95% prediction interval 0.50 to 0.65; 4511 participants, 11 trials; moderate‐quality evidence). Two trials reported serious adverse events. In one trial no adverse events occurred. In the other trial one of 51 diet plus physical activity participants compared with none of 51 comparator participants experienced a serious adverse event (low‐quality evidence). Cardiovascular mortality was rarely reported (four of 1626 diet plus physical activity participants and four of 1637 comparator participants (the RR ranged between 0.94 and 3.16; 3263 participants, 7 trials; very low‐quality evidence). Only one trial reported that no non‐fatal myocardial infarction or non‐fatal stroke had occurred (low‐quality evidence). Two trials reported that none of the participants had experienced hypoglycaemia. One trial investigated health‐related quality of life in 2144 participants and noted that a minimal important difference between intervention groups was not reached (very low‐quality evidence). Three trials evaluated costs of the interventions in 2755 participants. The largest trial of these reported an analysis of costs from the health system perspective and society perspective reflecting USD 31,500 and USD 51,600 per quality‐adjusted life year (QALY) with diet plus physical activity, respectively (low‐quality evidence). There were no data on blindness or end‐stage renal disease.
One trial compared a diet‐only intervention with a physical‐activity intervention or standard treatment. The participants had IGT. Three of 130 participants in the diet group compared with none of the 141 participants in the physical activity group died (very low‐quality evidence). None of the participants died because of cardiovascular disease (very low‐quality evidence). Altogether 57 of 130 diet participants (43.8%) compared with 58 of 141 physical activity participants (41.1%) group developed T2DM (very low‐quality evidence). No adverse events were recorded (very low‐quality evidence). There were no data on non‐fatal myocardial infarction, non‐fatal stroke, blindness, end‐stage renal disease, health‐related quality of life or socioeconomic effects.
Two trials compared physical activity with standard treatment in 397 participants. One trial included participants with IGT, the other trial included participants with IGT, IFG or both. One trial reported that none of the 141 physical activity participants compared with three of 133 control participants died. The other trial reported that three of 84 physical activity participants and one of 39 control participants died (very low‐quality evidence). In one trial T2DM developed in 58 of 141 physical activity participants (41.1%) compared with 90 of 133 control participants (67.7%). In the other trial 10 of 84 physical activity participants (11.9%) compared with seven of 39 control participants (18%) developed T2DM (very low‐quality evidence). Serious adverse events were rarely reported (one trial noted no events, one trial described events in three of 66 physical activity participants compared with one of 39 control participants ‐ very low‐quality evidence). Only one trial reported on cardiovascular mortality (none of 274 participants died ‐ very low‐quality evidence). Non‐fatal myocardial infarction or stroke were rarely observed in the one trial randomising 123 participants (very low‐quality evidence). One trial reported that none of the participants in the trial experienced hypoglycaemia. One trial investigating health‐related quality of life in 123 participants showed no substantial differences between intervention groups (very low‐quality evidence). There were no data on blindness or socioeconomic effects.
Authors' conclusions
There is no firm evidence that diet alone or physical activity alone compared to standard treatment influences the risk of T2DM and especially its associated complications in people at increased risk of developing T2DM. However, diet plus physical activity reduces or delays the incidence of T2DM in people with IGT. Data are lacking for the effect of diet plus physical activity for people with intermediate hyperglycaemia defined by other glycaemic variables. Most RCTs did not investigate patient‐important outcomes.
Fiscal targets. A guide to forecasters? Paredes, Joan; Pérez, Javier J.; Perez Quiros, Gabriel
Journal of applied econometrics,
June/July 2023, Volume:
38, Issue:
4
Journal Article
Peer reviewed
Open access
Summary
We formulate and estimate empirical models for a selection of EU countries (Germany, France, Italy, Spain, Portugal, and Ireland) to show that ex‐ante government (consumption) targets convey ...useful information about ex‐post fiscal developments, even if the track record of governments meeting their respective targets is low. The use of targets is particularly valuable when there is limited information about its implementation, for example, at the beginning of a fiscal year, when observed data are scarce. Thus, forecasters would be well advised to use fiscal targets as a guide in creating projections, despite the findings of a well‐established literature that reports that, ex post, governments tend to induce politically motivated biases in policy targets.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Soil drying and re-wetting (DRW) occurs at varying frequencies and intensities during crop production, and is deliberately used in water-saving irrigation techniques that aim to enhance crop water ...use efficiency. Soil drying not only limits root water uptake which can (but not always) perturb shoot water status, but also alters root synthesis of phytohormones and their transport to shoots to regulate leaf growth and gas exchange. Re-wetting the soil rapidly restores leaf water potential and leaf growth (minutes to hours), but gas exchange recovers more slowly (hours to days), probably mediated by sustained changes in root to shoot phytohormonal signalling. Partial rootzone drying (PRD) deliberately irrigates only part of the rootzone, while the remainder is allowed to dry. Alternating these wet and dry zones (thus re-wetting dry soil) substantially improves crop yields compared with maintaining fixed wet and dry zones or conventional deficit irrigation, and modifies phytohormonal (especially abscisic acid) signalling. Alternate wetting and drying (AWD) of rice can also improve yield compared with paddy culture, and is correlated with altered phytohormonal (including cytokinin) signalling. Both PRD and AWD can improve crop nutrition, and re-wetting dry soil provokes both physical and biological changes which affect soil nutrient availability. Whether this alters crop nutrient uptake depends on competition between plant and microbes for nutrients, with the rate of re-wetting determining microbial dynamics. Nevertheless, studies that examine the effects of soil DRW on both crop nutritional and phytohormonal responses are relatively rare; thus, determining the cause(s) of enhanced crop yields under AWD and PRD remains challenging.
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Abstract
The characteristic Cauchy problem of the Einstein field equations has been recently addressed from a completely abstract viewpoint by means of hypersurface data and, in particular, via the ...notion of double null data (DND). However, this definition was given in a partially gauge-fixed form. In this paper we generalize the notion of DND in a fully diffeomorphism and gauge covariant way, and show that the definition is complete by proving that no extra conditions are needed to embed the DND in some spacetime. The second aim of the paper is to show that the characteristic Cauchy problem satisfies a geometric uniqueness property. Specifically, we introduce a natural notion of isometry at the abstract level such that two DND that are isometric in this sense give rise to isometric spacetimes.
Abstract
General hypersurfaces of any causal character can be studied abstractly using the hypersurface data formalism. In the null case, we write down all tangential components of the ambient Ricci ...tensor in terms of the abstract data. Using this formalism, we formulate and solve in a completely abstract way the characteristic Cauchy problem of the Einstein vacuum field equations. The initial data is detached from any spacetime notion, and it is fully diffeomorphism and gauge covariant. The results of this paper put the characteristic problem on a similar footing as the standard Cauchy problem in General Relativity.
We set out a model to compute short-term forecasts of the euro area GDP growth in real time. To allow for forecast evaluation, we construct a real-time dataset that changes for each vintage date and ...includes the exact information that was available at the time of each forecast. With this dataset we show that our simple factor model algorithm, which uses an easy-to-replicate methodology, is able to forecast the euro area GDP growth as well as professional forecasters who can combine the best forecasting tools with the possibility of incorporating their own judgement. In this context, we provide examples showing how data revisions and data availability affect point forecasts and forecast uncertainty.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
This review summarizes and organizes the literature on life cycle assessment (LCA), life cycle energy analysis (LCEA) and life cycle cost analysis (LCCA) studies carried out for environmental ...evaluation of buildings and building related industry and sector (including construction products, construction systems, buildings, and civil engineering constructions). The review shows that most LCA and LCEA are carried out in what is shown as “exemplary buildings”, that is, buildings that have been designed and constructed as low energy buildings, but there are very few studies on “traditional buildings”, that is, buildings such as those mostly found in our cities. Similarly, most studies are carried out in urban areas, while rural areas are not well represented in the literature. Finally, studies are not equally distributed around the world.
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