Network interventions     

TW Valente 《Science (New York, N.Y.)》2012,337(6090):49-53

The term "network interventions" describes the process of using social network data to accelerate behavior change or improve organizational performance. In this Review, four strategies for network interventions are described, each of which has multiple tactical alternatives. Many of these tactics can incorporate different mathematical algorithms. Consequently, researchers have many intervention choices at their disposal. Selecting the appropriate network intervention depends on the availability and character of network data, perceived characteristics of the behavior, its existing prevalence, and the social context of the program.  相似文献   

Motivations and support for regulations: a typology of eastern wild turkey hunters     

Cristina Watkins  Carlotta Caplenor  David Buehler  Roger Applegate 《Human Dimensions of Wildlife》2018,23(5):433-445

To determine the diverse motivations of eastern wild turkey (Meleagris gallopavo) hunters, a self-administered questionnaire was developed and mailed to a sample of 5,000 licensed turkey hunters in Tennessee (response rate = 36%). A cluster analysis yielded three types of respondents in terms of their hunting motivations: social harvesters (44%), experiential harvesters (22%), and social outdoor enthusiasts (34%). Hunters in these segments were then analyzed to compare their support for various hunting regulations. While 61% of Tennessee eastern wild turkey hunters reported to be satisfied with current regulations, harvest-motivated hunters were less receptive to regulations that would limit season lengths or bag limits while socially motivated hunters were more accepting. The hunter groups did not differ in their preference for decentralizing regulations by management zones. Findings from this article may guide wildlife managers in designing socially acceptable regulations.  相似文献   

Optimization of phosphorus content in high plant protein practical diets for Senegalese sole (Solea senegalensis,Kaup 1858) juveniles: influence on growth performance and composition of whole body and vertebrae          下载免费PDF全文

E. Salas‐Leiton  J. Dias  P. Gavaia  A. Amoedo  L.M.P. Valente 《Aquaculture Nutrition》2017,23(1):18-29

Practical diets containing PP sources were elaborated. Increasing levels of di‐calcium phosphate were added to diets leading to five different dietary available P levels: 2.5, 3.2, 6.0, 6.5 and 8.0 g kg^?1 dry diet. The dietary treatments were tested in 13.5 g Senegalese sole juveniles throughout an 82‐day experimental period. Dietary P content had no effect on the productive parameters, while nutrient intake was also similar among dietary treatments, except P intake. Dry matter ADC ranged between 54.9% and 64.0%, and the highest P ADCs value (47.2 ± 0.7%) was achieved in fish fed AP6.0. Dietary phosphorus level significantly influenced body lipid and P compositions. Regression analysis performed on whole‐body P and ash contents fitted to quadratic models. Vertebral bone P content was low but increased significantly with increasing dietary P levels. Bone density and deformities occurrence were, however, similar between experimental conditions. An altered status of bone formation–resorption processes in soles fed the lowest P content diet might be inferred from ALP and TRAP activities. In conclusion, overall results state a high tolerance of Senegalese sole to low P content diets and support the utilization of practical diets with high plant protein content.  相似文献   

Effects of Feeding Levels on Growth Response,Body Composition,and Energy Expenditure in Blackspot Seabream,Pagellus bogaraveo,Juveniles     

Rodrigo Otávio De Almeida Ozório  Carlos Andrade  Viriato Manuel Freitas Andrade Timóteo  Luís Eugénio Castanheira da Conceição  Luisa Maria Pinheiro Valente 《Journal of the World Aquaculture Society》2009,40(1):95-103

Although reported as a slow growing species, to date information regarding nutritional dynamics of blackspot seabream, Pagellus bogaraveo, is limited, especially during ongrowing phase. This study determined the effects of different feeding levels on growth response, body composition, and energy expenditure of blackspot seabream juveniles (initial weight = 64 g). Fish were allocated in nine indoor tanks (15 fish per tank) and fed a basal diet twice daily at increasing levels (2.5, 3.3, and 4.1 g feed/kg^0.8/d) for 138 d. Growth response decreased with decreasing feeding levels, but only at 2.5 g feed/kg^0.8/d (P < 0.001). Differences in growth rates were positively correlated with body lipid content (r² = 0.90). Net protein utilization decreased with each increase in feeding level. The energy requirement for zero growth (maintenance) and the estimated energy loss on starvation were calculated as 22.6 and 17.9 kJ/kg^0.8/d, respectively. The energy cost for protein and lipid gain was calculated as 3.8 and 1.4 kJ/kJ energy deposited, respectively. This study suggested that blackspot seabream may grow slower than the other close‐related species because of its higher demand of dietary protein energy in favor of lipid deposition.  相似文献   

Apparent digestibility coefficients of processed agro‐food by‐products in European seabass (Dicentrarchus labrax) juveniles          下载免费PDF全文

I. Campos  E. Matos  C. Aragão  M. Pintado  L.M.P. Valente 《Aquaculture Nutrition》2018,24(4):1274-1286

Apparent digestibility coefficients (ADCs) of processed agro‐food by‐products were assessed in European seabass (Dicentrarchus labrax). Each experimental diet was obtained by replacing 300 g/kg of a commercial‐based diet used as reference (REF) with a test ingredient: wheat germ (GERM), okara meal (OKA), poultry by‐product meal (POULT), steam hydrolysed (FeHY) and enzyme‐treated feather meal (FeENZ), beta‐lactoglobulin (β‐Lg) and peptide fractions >3,000 Da obtained from brewer's yeast (YeastP) and fish by‐products (FishP). Dry matter ADC was highest in β‐Lg (95%) and lowest in OKA (40%). Protein ADCs were high in β‐Lg, FishP, GERM and POULT (>93%); intermediate in FeHY and FeENZ (85%–88%); and moderate in OKA and YeastP (70%–78%). The essential amino acids' ADC mean was above 91% in POULT, β‐Lg, GERM and FishP, 84%–89% in FeHY and FeENZ and 73%–76% in YeastP and OKA. Energy ADC was highest in POULT and β‐Lg (89%–95%) and lowest in YeastP and OKA (61%–64%). Lipid ADC was highest for POULT and GERM (100%). Phosphorus ADC was lowest in GERM (19%) and highest in β‐Lg (88%). FeHY, FeENZ, POULT, GERM, FishP and β‐Lg are highlighted as protein sources for European seabass.  相似文献   

Toward forest ‘‘sprawl':monitoring and planning a changing landscape for urban sustainability     

Luca Salvati  Carlotta Ferrara  Anastasios Mavrakis  Andrea Colantoni 《林业研究》2016,27(1):175-184

The present study analyzes the structure and dynamics of the forest landscape in a peri-urban area(Rome, Italy) during the city's expansion from 1949 to2008 using landscape metrics and change detection analysis of digital maps of the area(1500 km2). While urban settlements increased continuously from 6.5 to 27.5 % of the study area, woodlands changed less clearly, with a moderate increase(from 11.2 to 11.9 % of the total area)and a higher fragmentation as a consequence of Rome's expansion. The structure of forest landscape changed along the urban-to-rural gradient with patch size increasing with the distance to the inner city in 1949 and substantial landscape homogeneity in 2008. The indicators proposed in this study inform dedicated measures for conserving forest and maintaining landscape diversity. Measures adopted in Rome's forestation plan to counteract woodlandffragmentation were analyzed and discussed. Based on the complex landscape dynamics found for Rome, an integrated multiscale planning approach targeting forest conservation is considered a key contribution to urban sustainability.  相似文献   

Comparison of different PCR tests to identify Monilinia fructicola          下载免费PDF全文

L. Riccioni  M. T. Valente 《EPPO Bulletin》2015,45(1):33-40

Monilinia fructicola was until very recently a regulated pest in the European Union, and EU countries were requested to monitor its presence on their territories. As accredited laboratories should use validated tests, the mycological laboratory of CRA‐PAV carried out a validation process for the multiplex based PCR test (Coté et al., 2004 ), that is one of the most widely used tests for the identification of M. fructicola, although this test is not described in the EPPO diagnostic protocol PM 7/18 (2) because the validation data were lacking. The performance characteristics of this multiplex PCR test were established according to the EPPO Standard PM 7/98 (1) and the test was compared in a collaborative study with the end point PCR test (Ioos & Frey, 2000 ), considered as the ‘standard test’. The validation data were obtained using different isolates of M. fructicola, M. laxa, M. fructigena and Monilia polystroma, as well as different fruit tissues. Four series of the DNA target at different concentration, repeated three times, were analyzed in four Italian laboratories. The results showed that the multiplex PCR detection test (Coté et al., 2004 ) was fit for diagnostic purpose, although the analytical sensitivity was significantly lower compared to the conventional PCR ‘standard test’.  相似文献   

Modelling interception loss from evergreen oak Mediterranean savannas: Application of a tree-based modelling approach     

F.L. Pereira  J.H.C. Gash  J.S. David  T.S. David  P.R. Monteiro  F. Valente 《Agricultural and Forest Meteorology》2009,149(3-4):680-688

In a previous study, it was shown that an isolated, fully saturated tree-crown behaves like a wet bulb, allowing evaporation of intercepted rainfall to be estimated by a simple diffusion equation for water vapour. This observation was taken as the basis for a new approach in modelling interception loss from savanna-type woodland, whereby the ecosystem evaporation is derived by scaling up the evaporation from individual trees, rather than by considering a homogeneous forest cover. Interception loss from isolated trees was estimated by combining the aforementioned equation for water vapour flux with Gash's analytical model. A new methodology, which avoids the subjectivity inherent in the Leyton method, was used for estimating the crown storage capacity. Modelling performance was evaluated against data from two Mediterranean savanna-type oak woodlands (montados) in southern Portugal. Interception loss estimates were in good agreement with observations in both sites. The proposed modelling approach is physically based, requires only a limited amount of data and should be suitable for the modelling of interception loss in isolated trees and savanna-type ecosystems.  相似文献   

Detection of the Maedi Visna Virus in the popliteal lymph nodes of sheep infected by the respiratory route     

S. Preziuso  G. E. Magi  C. Valente  V. Cuteri 《Veterinary research communications》2009,33(Z1):153-155

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Rearing temperature affects Senegalese sole (Solea senegalensis) larvae protein metabolic capacity     

Catarina Campos  M. Filipa Castanheira  Sofia Engrola  Luísa M. P. Valente  Jorge M. O. Fernandes  Luís E. C. Conceição 《Fish physiology and biochemistry》2013,39(6):1485-1496

The present work examined the short- and long-term effects of three rearing temperatures on protein metabolism and growth trajectories of Senegalese sole larvae using ¹⁴C-labelled Artemia protein as feed. A first feeding trial was performed on larvae reared at 15, 18 and 21 °C (at 26, 17 and 14 days post-hatching (dph), respectively) and a second trial conducted on post-larvae after transfer to the same rearing temperature (~20 °C) (49, 35 and 27 dph, in larvae initially reared at 15, 18 and 21 °C, respectively). Temperature greatly influenced larvae relative growth rate (RGR) and survival, since growth at 15 °C was severely depressed. Protein digestibility and retention was highest at 18 °C during the first trial (85.35 ± 1.16 and 86.34 ± 2.33 %, respectively). However, during the second trial, post-larvae from 15 °C had the highest feed intake and protein digestibility (3.58 ± 1.54 and 75.50 ± 1.35 %, respectively), although retention was similar between treatments. Furthermore, after transfer to 20 °C larvae from 15 °C experienced compensatory growth, which was observed until 121 dph, and confirmed by RGR values, which were significantly higher at 15 ºC than at 21 ºC or 18 ºC. Results from the present study show that Solea senegalensis larval development, survival and protein digestion and retention are highly affected by thermal history.  相似文献