The study of landscape connectivity in conservation has increased considerably since the early part of the 21st century. While the implications of landscape connectivity are self-evident for ...conservation, they are also important for physical geography since a proper understanding of landscape patterns and processes allows for better landscape management practices, which are at the core of geography. This paper presents a review of the literature based on 162 publications from 2000 to 2013, in which we evaluated the current state and recent advances in the integration of landscape connectivity in the identification and planning of conservation areas. The literature review and data analysis were based on a database organized into five categories: General information, study areas, research objectives, research methods in connectivity studies, and integration of connectivity with conservation. We found a substantial increase in the number of publications relating to connectivity and conservation from 2008 to 2013. Least cost analysis was the method most commonly applied. We found no implementation of landscape connectivity proposals generated by the studies (e.g. potential corridors) into real landscape elements to ensure the permanence and functionality of ecosystems. We identified four important niches for potential future research projects: a) connectivity and climate change, b) contribution of connectivity studies to restoration planning, c) connectivity and land cover/land use change modeling and planning, d) contribution of connectivity analysis in the provision of ecosystem services across landscapes.
C3 glomerulonephritis is a clinicopathologic entity defined by the presence of isolated or dominant deposits of C3 on immunofluorescence. To explore the effect of immunosuppression on C3 ...glomerulonephritis, we studied a series of 60 patients in whom a complete registry of treatments was available over a median follow-up of 47months. Twenty patients had not received immunosuppressive treatments. In the remaining 40 patients, 22 had been treated with corticosteroids plus mycophenolate mofetil while 18 were treated with other immunosuppressive regimens (corticosteroids alone or corticosteroids plus cyclophosphamide). The number of patients developing endstage renal disease was significantly lower among treated compared with untreated patients (3 vs. 7 patients, respectively). No patient in the corticosteroids plus mycophenolate mofetil group doubled serum creatinine nor developed end-stage renal disease, as compared with 7 (significant) and 3 (not significant), respectively, in patients treated with other immunosuppressive regimens. Renal survival (100, 80, and 72% at 5years) and the number of patients achieving clinical remission (86, 50, and 25%) were significantly higher in patients treated with corticosteroids plus mycophenolate mofetil as compared with patients treated with other immunosuppressive regimens and untreated patients, respectively. Thus, immunosuppressive treatments, particularly corticosteroids plus mycophenolate mofetil, can be beneficial in C3 glomerulonephritis.
A systematic review and meta‐analysis of on farm management and water quality as risk factors triggering pathogen outbreaks in tilapia culture is presented. A total of 121 papers from 28 countries, ...37 devoted to management and 84 to water quality associated with the presence of pathogens in tilapia culture were analysed. Most of research has been made on ponds, focusing on bacteria and metazoans. Meta‐analysis reveals the proportion of research showing statistical inferences between management (34%), water quality (38% for bacteria and 16.2% for metazoans) and pathogen outbreaks. The most cited parameters related to pathogens outbreaks were temperature (>30°C), dissolved oxygen (<5.0 mg/L), pH (<8.0) and ammonia (1.0 >mg/L) 65, 38, 32 and 34 papers, respectively. However, statistical inference was <20%. Meta‐analysis reveals tendencies between high temperatures (30–35°C), low dissolved oxygen (<5 mg/L) and high NH3 (1–5 mg/L) with pathogen outbreaks. Despite the knowledge about the relationship between management and water quality as factors for pathogen effects, most information is descriptive and empirical. Future research on tilapia culture outbreaks should be focused on the effects of multiple stressors affecting tilapia pathogen outbreaks, thereby generating strategies to prevent diseases and financial losses.
The selective functionalization of carbon nanotube surfaces is crucial for many potential applications of these materials. For this purpose several oxidants, among other substances, are used. The aim ...is to reach a large degree of functionalization which depends on the oxidant character of the reagent. For this reason the functionalization of multiwall carbon nanotubes (MWCNTs) by treatment with ozone in basic solution is studied. At basic pHs, ozone results into hydroxyl radicals whose reduction potential is very high (E° = 3.06 V). The results have been compared to those obtained by ozone in gas phase and with cold oxygen plasma. The oxidation with ozone in basic solution seems to be kinetically restricted. As a consequence, the degree of oxidation in this medium is smaller than this of ozone gas, in spite of the larger oxidation capacity of the former. The oxygen-containing groups fixed by these two treatments are mainly attached to defects of the nanotubes. Moreover, no modification of the graphene layers and no porosity result from these treatments. The oxygen plasma treatment stands out in the content of oxygen groups fixed to the MWCNTs, as it is by far more effective, although some of these groups have relatively low thermal stability. Nevertheless, this treatment mainly fixes the oxygen groups on the walls of the nanotubes.
High-energy ball milling is a process suitable for producing composite powders whose achieved microstructure can be controlled by the processing parameters. Through this technique, it is possible to ...obtain a homogeneous distribution of reinforced material into a ductile metal matrix. In this work, some Al/CGNs nanocomposites were fabricated through a high-energy ball mill to disperse nanostructured graphite reinforcements produced in situ in the Al matrix. To retain the dispersed CGNs in the Al matrix, avoiding the precipitation of the Al
C
phase during sintering, the high-frequency induction sintering (HFIS) method was used, which allows rapid heating rates. For comparative purposes, samples in the green and sintered state processed in a conventional electric furnace (CFS) were used. Microhardness testing was used to evaluate the effectiveness of the reinforcement in samples under different processing conditions. Structural analyses were carried out through an X-ray diffractometer coupled with a convolutional multiple whole profile (CMWP) fitting program to determine the crystallite size and dislocation density; both strengthening contributions were calculated using the Langford-Cohen and Taylor equations. According to the results, the CGNs dispersed in the Al matrix played an important role in the reinforcement of the Al matrix, promoting the increase in the dislocation density during the milling process. The strengthening contribution of the dislocation density was ~50% of the total hardening value, while the contribution by dispersion of CGNs was ~22% in samples with 3 wt. % C and sintered by the HFIS method. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to analyze the morphology, size, and distribution of phases present in the Al matrix. From the analyses carried out in AFM (topography and phase images), the CGNs are located mainly around crystallites and present height profiles of 1.6 to 2 nm.
•Characterisation of virgin olive oils produced in Extremadura.•Analysis of fatty acids, triglycerides, sterols and triterpenic dialcohols.•Relation between chemistry composition and ripeness ...maturation.
The aim of this study was the classification of olive oil according to the stage of ripeness of the olives used for its manufacture. A discriminant analysis was applied taking as dependent variables the fatty acids, triglycerides and sterols profile. The evolution of parameters of quality of the oils during ripening of the fruit has also been studied in three successive crops. The results of the classification shows that 88.5% of selected original grouped cases are correctly classified (85.7% green, 80% spotted and 78.9% ripe) and furthermore the validation classified the 69.6% of the unselected original cases. The most discriminating variables have been: avenasterol, linolenic acid, β-sitosterol and gadoleico. Fig. 1 shows graphically the values of the canonical discriminant functions and the centroids of the intervals of three or the maturity index.
A new Y-based metal–organic framework (MOF) GR-MOF-6 with a chemical formula of {YL(DMF)2·(DMF)} n {H3L = 5-(4-carboxyphenyl)ethynyl isophthalic acid; DMF = N,N-dimethylformamide} has been prepared ...by a solvothermal route. Structural characterization reveals that this novel material is a three-dimensional MOF in which the coordination of the tritopic ligand to Y(III) metal ions leads to an intercrossing channel system extending over three dimensions. This material has proven to be a very efficient catalyst in the cyanosilylation of carbonyls, ranking second in catalytic activity among the reported rare earth metal-based MOFs described so far but with the lowest required catalyst loading. In addition, its electrophoretic behavior has been studied in depth, providing a zero-charge point between pH 4 and 5, a peak electrophoretic mobility of −1.553 μm cm V–1 s–1, and a ζ potential of −19.8 mV at pH 10.
Type 2 diabetes (T2D) affects a large part of the adult population and impairs its quality of life. Because of this, natural compounds with antioxidant, anti-inflammatory and hypoglycemic properties ...have been used as adjuvants. Among these compounds, resveratrol (RV) stands out, a polyphenol that has been studied in several clinical trials, the results of which are controversial. We conducted a randomized clinical trial on 97 older adults with T2D to evaluate the effect of RV on oxidative stress markers and sirtuin 1, using doses of 1000 mg/day (EG1000,
= 37) and 500 mg/day (EG500,
= 32) compared with a placebo (PG,
= 28). Biochemical markers, oxidative stress and sirtuin 1 levels were measured at baseline and after six months. We observed a statistically significant increase (
< 0.05) in total antioxidant capacity, antioxidant gap, the percentage of subjects without oxidant stress and sirtuin 1 levels in EG1000. In the PG, we observed a significant increase (
< 0.05) in lipoperoxides, isoprostanes and C-reactive protein levels. An increase in the oxidative stress score and in the percentage of subjects with mild and moderate oxidative stress was observed too. Our findings suggest that 1000 mg/day of RV exerts a more efficient antioxidant effect than 500 mg/day.
•Different correlations for flow boiling in microfin tubes are evaluated.•Akhavan-Behabadi et al. correlation presents the best predictions.•Min. and max. deviations occur with R134a and R450A, ...respectively.•R450A and R134a evaporator performances are almost the same.•Due to high R448A glide, its evaporator performance is very different from R404A.
When retrofitting new refrigerants in an existing vapour compression system, their adaptation to the heat exchangers is a major concern. R450A and R448A are commercial non-flammable mixtures with low GWP developed to replace the HFCs R134a and R404A, fluids with high GWP values. In this work the evaporator performance is evaluated through a shell-and-microfin tube evaporator model using R450A, R448A, R134a and R404A. The accuracy of the model is first studied considering different recently developed micro-fin tube correlations for flow boiling phenomena. The model is validated using experimental data from tests carried out in a fully monitored vapour compression plant at different refrigeration operating conditions. The main predicted operational parameters such as evaporating pressure, UATP, and cooling capacity, when compared with experimental data, fit within ±10% using the Akhavan-Behabadi et al. correlation for flow boiling. Results show that R450A and R404A are the refrigerants in which the model fits better, even though R448A and R134a predictions are also accurate.
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