Molecular characterization of avipoxviruses circulating in Windhoek district,Namibia 2021     

Umberto MOLINI  Vimanuka MUTJAVIKUA  Mari de VILLIERS  Lourens de VILLIERS  Alaster SAMKANGE  Lauren M. COETZEE  Siegfried KHAISEB  Giovanni CATTOLI  William G. DUNDON 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2022,84(5):707

Samples from eleven birds (chicken, dove and peacock) with symptoms of fowlpox, caused by the avipoxvirus (APV), were collected in seven different areas of the Windhoek district, Namibia between April and October 2021. A fragment of the 4b core protein and the DNA polymerase gene of APV were amplified by PCR from the DNA of the samples and sequenced. Phylogenetic analysis revealed that the viruses present in the chickens all belonged to clade A1 while the viruses in the doves and peacock were from subclade A3.1. This is the first report of subclade A3.1 avipoxvirus in peacock. In addition, all of the samples obtained from chickens were shown by PCR to be positive for the integration of reticuloendotheliosis virus while those from the doves and peacocks were negative. This study is the first characterization of avipoxvirus in Namibia and provides additional information on the presence of avipoxvirus in southern Africa.  相似文献   

Does post‐anthesis heat stress affect plant phenology,physiology, grain yield and protein content of durum wheat in a semi‐arid Mediterranean environment?     

Salvatore L. Cosentino  Emanuele Sanzone  Giorgio Testa  Cristina Patan  Umberto Anastasi  Danilo Scordia 《Journal of Agronomy and Crop Science》2019,205(3):309-323

Increasing air temperature due to changing climate is projected to decrease the length of the growing season, hasten vegetative development and maturation, and ultimately affect yield of many C3 crops. Previous multilocation trials highlighted strong relationships between thermal trends in the interval “beginning of flowering‐end of grain filling” and grain yield, and protein content in durum wheat (Triticum turgidum subsp. durum (Desf.) Husn.). With the aim to confirm these relationships, nine durum wheat genotypes, including old (Capeiti 8, Senatore Cappelli and Trinakria) and modern (Amedeo, Arcangelo, Mongibello, Simeto, and Svevo) varieties and a Sicilian landrace (Russello) were grown at three different sites representing a climate gradient in Sicily, Italy. Moreover, the effect of post‐anthesis heat stress on these durum wheats was further investigated in two contrasting environments: open‐field (control—C) and greenhouse heat stress (HS). HS shortened the interval “beginning‐end of flowering” of 1.5 days across genotypes, and the “end of flowering‐beginning of grain filling” and maturation of 4.9 days, with a range of 1 day in Arcangelo to 11 days in Cappelli. Advances in main phenophases significantly decreased kernel weight (KW) and grain yield (GY), whereas grain protein content (PC) increased. As expected, a negative relationship was observed between GY and PC, while positive relationships were found for GY and grain‐filling duration (GFD), and GY and KW. Genotypes responded differently to heat stress, as evidenced by the net photosynthesis, transpiration rate, instantaneous water use efficiency and dry matter accumulation in kernels. Genotypes were ranked according to the heat susceptibility index (HSI): Amedeo, Arcangelo, Capeiti 8, Svevo and Trinakria resulted heat‐tolerant. These varieties were characterized by an early trigger of dry matter accumulation in kernels under HS (Amedeo, Arcangelo and Trinakria), or showed similar length of the GFD (Capeiti 8) between environments. The multilocation trial confirmed a negative relationship between maximum temperatures and grain yield, and a positive relationship between minimum temperatures and protein content during grain–filling periods. Research focusing on agronomic strategies, phenology and breeding for tolerance to heat stress is of strategic importance to cope with the detrimental effect of global warming in semi‐arid climates.  相似文献   

Monitoring managed forest structure at the compartment-level under different silvicultural heritages: An exploratory data analysis in Italy     

Claudia Becagli  Umberto Di Salvatore  Gianfranco Fabbio  Ferretti Fabrizio  Luca Salvati 《Journal of Sustainable Forestry》2013,32(3):234-250

ABSTRACT

The more and more diffused multifunctional role addressed nowadays to public forests, calls for targeted analysis aimed at highlighting the overall outcome of different practices implemented on the same forest compartment, according to the locally prevailing function. This study was carried out in four Italian beech forests across a latitudinal gradient representative of multiple management history, stand structure, and dominant stand age. We analyze forest structure at the compartment scale before and after silvicultural practices. We aim to explore relationships and similarities between 10 stand attributes (mensurational and structural variables) to identify relevant indicators for the monitoring and management of forest ecosystems. Results indicate changing patterns of correlation and similarity among mensurational variables following practice implementation. A sensitivity gradient to silvicultural practice was finally identified within the four sites investigated as a result of the diverging stand structure. Our approach suggests a way and provides an insight for the design of adaptive forestry management practices required to meet environmental targets, in addition to the already acknowledged supply of primary goods and services.  相似文献   

Relationship between particle density and soil bulk chemical composition     

Dario Di Giuseppe  Massimiliano Melchiorre  Umberto Tessari  Barbara Faccini 《Journal of Soils and Sediments》2016,16(3):909-915

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Testing Scandium Method to Quantify Suspended Particles Adhesion to the External Surface of Periphyton Communities     

Sansone  Umberto  Belli  Maria  Fernandez  José A.  Comans  Rob N. J.  Jeran  Zvonka  Cavolo  Fabio  Barbizzi  Sabrina  De Zorzi  Paolo  Jacimovic  Radojko 《Water, air, and soil pollution》2002,141(1-4):313-324

Aquarium experiments were performed to quantify the inorganic fraction of suspended particles deposited on the external surface of aquatic biota. The mass of suspended particles retained on the surfaces of microalgae growing on submerged substrates and the algal biomass were determined by comparing the scandium content of suspended material with that in algal communities. Scandium, a predominantly soil-associated trace element, has been used as a ‘tracer’ for the inorganic component of suspended particles, because this element is geologically ubiquitous in soils, and it is recognized that it cannot cross natural membranes of plants and other organisms. The algal biomass determined using the scandium content was compared with biomass values calculated using phytopigments as estimates of periphyton biomass. The results indicate that the suspended particle mass adhering to the external periphyton surface may accounted for up to 55% of the total mass collected on submerged artificial substrates.  相似文献   

Identification of herbaceous hosts of the <Emphasis Type="Italic">Grapevine Pinot gris virus</Emphasis> (GPGV)     

Valeria Gualandri  Elisa Asquini  Pierluigi Bianchedi  Laura Covelli  Matteo Brilli  Umberto Malossini  Paola Bragagna  Pasquale Saldarelli  Azeddine Si-Ammour 《European journal of plant pathology / European Foundation for Plant Pathology》2017,147(1):21-25

Grapevine Pinot gris Virus (GPGV) is a single stranded RNA of the genus Trichovirus infecting grapevine (Vitis vinifera) and associated with stunting, chlorotic mottling and leaf deformation symptoms. During a monitoring of GPGV infection in vineyards of the Trentino region in Italy, we have detected the virus in the herbaceous plants Silene latifolia subsp. Alba (Mill.) (bladder campion) and Chenopodium album L. (white goosefoot), which showed symptoms of viral infection. The full-length GPGV RNA genome, amplified from these infected hosts, was sequenced and a phylogenetic analysis revealed that its closest relative is the strain SK13, recently isolated in Slovakia. Our results indicate that herbaceous plants can be considered as a reservoir for the GPGV virus. This finding is important for studying the epidemiological aspects of GPGV disease and to formulate appropriate control measures.  相似文献   

Using digital repeat photography and eddy covariance data to model grassland phenology and photosynthetic CO₂ uptake     

Mirco Migliavacca  Marta Galvagno  Edoardo CremoneseMicol Rossini  Michele Meroni  Oliver SonnentagSergio Cogliati  Giovanni MancaFabrizio Diotri  Lorenzo BusettoAlessandro Cescatti  Roberto ColomboFrancesco Fava  Umberto Morra di CellaEmiliano Pari  Consolata SiniscalcoAndrew D. Richardson 《Agricultural and Forest Meteorology》2011,151(10):1325-1337

The continuous and automated monitoring of canopy phenology is of increasing scientific interest for the multiple implications of vegetation dynamics on ecosystem carbon and energy fluxes. For this purpose we evaluated the applicability of digital camera imagery for monitoring and modeling phenology and physiology of a subalpine grassland over the 2009 and 2010 growing seasons.We tested the relationships between color indices (i.e. the algebraic combinations of RGB brightness levels) tracking canopy greenness extracted from repeated digital images against field measurements of green and total biomass, leaf area index (LAI), greenness visual estimation, vegetation indices computed from continuous spectroradiometric measurements and CO₂ fluxes observed with the eddy covariance technique. A strong relationship was found between canopy greenness and (i) structural parameters (i.e., LAI) and (ii) canopy photosynthesis (i.e. Gross Primary Production; GPP). Color indices were also well correlated with vegetation indices typically used for monitoring landscape phenology from satellite, suggesting that digital repeat photography provides high-quality ground data for evaluation of satellite phenology products.We demonstrate that by using canopy greenness we can refine phenological models (Growing Season Index, GSI) by describing canopy development and considering the role of ecological factors (e.g., snow, temperature and photoperiod) controlling grassland phenology. Moreover, we show that canopy greenness combined with radiation use efficiency (RUE) obtained from spectral indices related to photochemistry (i.e., scaled Photochemical Reflectance Index) or meteorology (i.e., MOD17 RUE) can be used to predict daily GPP.Building on previous work that has demonstrated that seasonal variation in the structure and function of plant canopies can be quantified using digital camera imagery, we have highlighted the potential use of these data for the development and parameterization of phenological and RUE models, and thus point toward an extension of the proposed methodologies to the dataset collected within PhenoCam Network.  相似文献   

Fuel vertical structure affects fire sustainability and behaviour of prescribed burning in Spartium junceum shrublands     

Daniele Castagneri  Assunta Esposito  Giovanni Bovio  Stefano Mazzoleni  Umberto Seneca  Ambra Elena Catalanotti  Davide Ascoli 《Annals of Forest Science》2013,70(8):863-871

? Context

Prescribed burning is increasingly recommended to control encroaching shrublands in the Mediterranean area.

? Aims

The aims of this paper are to analyze the fuel structural characteristics of Spartium junceum and how they influence fire behaviour during prescribed burning.

? Methods

Two winter–spring prescribed burns were conducted in 2009 and 2011. Fuel load and structure of S. junceum shrubs were assessed using the Cube Method, and shrub 3-D models were built using the FIRE PARADOX FUEL MANAGER software. Allometric equations to estimate S. junceum fuel load were developed. During burning, thermocouples measured temperature variations, which were then analyzed relative to fuel characteristics.

? Results

Fuel load components and distribution were strictly related to shrub height; in tall shrubs, most of the fine fuel was more than 1.5 m aboveground. Due to fuel vertical discontinuity, not all shrubs were burned in the fires, but wind increased fire sustainment and fuel consumption. Maximum temperatures (over 800 °C) and residence times were positively related to fuel load.

? Conclusion

S. junceum tall shrublands represent high hazard formations due to their elevated fuel load, mostly in fine fuel fractions. Vertical discontinuity among fuel strata limits fire propagation in mild weather conditions. Winter–spring prescribed burning cannot eliminate S. junceum shrublands, but do create shrub cover discontinuity. As S. junceum has fire-adapted morphological traits, a single burn is insufficient to control it.  相似文献   

Apple juice clarification by immobilized pectolytic enzymes in packed or fluidized bed reactors     

Diano N  Grimaldi T  Bianco M  Rossi S  Gabrovska K  Yordanova G  Godjevargova T  Grano V  Nicolucci C  Mita L  Bencivenga U  Canciglia P  Mita DG 《Journal of agricultural and food chemistry》2008,56(23):11471-11477

The catalytic behavior of a mixture of pectic enzymes, covalently immobilized on different supports (glass microspheres, nylon 6/6 pellets, and PAN beads), was analyzed with a pectin aqueous solution that simulates apple juice. The following parameters were investigated: the rate constant at which pectin hydrolysis is conducted, the time (tau(50)) in which the reduction of 50% of the initial viscosity is reached, and the time (tau(comp,dep)) required to obtain complete depectinization. The best catalytic system was proven to be PAN beads, and their pH and temperature behavior were determined. The yields of two bed reactors, packed or fluidized, using the catalytic PAN beads, were compared to the circulation flow rate of real apple juice. The experimental conditions were as follows: pH 4.0, T = 50 degrees C, and beads volume = 20 cm(3). The initial pectin concentration was the one that was present in our apple juice sample. No differences were observed at low circulation rates, while at higher recirculation rates, the time required to obtain complete pectin hydrolysis into the fluidized reactor was found to be 0.25 times smaller than in the packed bed reactor: 131 min for the packed reactors and 41 min for the fluidized reactors.  相似文献   

Identification of porcine circovirus-3 in Mozambique     

Anahory  Iolanda Vieira  Franzo  Giovanni  Settypalli  Tirumala B. K.  Mapaco  Lourenço P.  Achá  Sara J.  Molini  Umberto  Cattoli  Giovanni  Lamien  Charles E.  Dundon  William G. 《Veterinary research communications》2022,46(2):593-596

Veterinary Research Communications - Porcine circovirus 3 (PCV-3) has been associated with an assortment of clinical conditions in pigs and has been reported in many countries worldwide. In Africa...  相似文献