Effect of hyperbaric,controlled atmosphere,and UV treatments on peach volatiles     

Dong Sik Yang  René R. Balandrán-Quintana  Carlos F. Ruiz  Romeo T. Toledo  Stanley J. Kays 《Postharvest Biology and Technology》2009,51(3):334-341

The effect of hyperbaric (HP) and controlled atmosphere (CA) storage and prestorage treatment with ultra violet (UV) radiation on the volatile chemistry of peach [Prunus persica (L.) Batsch] fruit was assessed. Peach volatiles were analyzed using a dynamic headspace system with Tenax trap, automated short path thermal desorption, and GC–MS. The composition of volatile compounds emanating from the fruit varied quantitatively and qualitatively with storage (4 weeks). A total of 65 volatiles were identified, 21 prior to storage and 59 after 4 weeks storage. Six of the prestorage volatiles were not found after storage. The concentration of total volatiles and esters, the highest relative proportion of primary classes increased 32.5- and 36.5-fold, respectively, during storage. Ethyl butanoate, ethyl hexanoate, and ethyl heptanoate contributed to peach aroma due to their low odor thresholds and high concentrations. Using a factorial design (2 × 2 × 2), the main effects [storage pressure (P), storage gas atmosphere (A), and UV pretreatment] and interactions (P × A, P × UV, A × UV, and P × A × UV) were determined. P contributed most to the concentration of total volatile compounds followed by A; HP and HP + CA with or without UV significantly reduced the concentration of total volatiles and esters. Prestorage UV irradiation treatment did not affect the emission of volatile compounds. Principal component analysis (PCA) using 59 volatile compounds emanating from stored fruit indicated a significant effect of P and A on the emission of volatiles that were divided into four treatment groups accounting for 67.5% of the total variance, i.e., AP + Air, AP + CA, HP + Air, and HP + CA. The PCA distribution indicated which compounds contributed most to differences in volatile pattern among treatments: ethyl (Z)-4-octenoate, ethyl heptanoate, ethyl octanoate, and decanal (AP + Air); 3-methylbutyl acetate, ethyl butanoate, ethyl hexanoate, and 2-methylbutanoate (HP + CA); nonanal and hexanal (AP + CA); and hexyl acetate (HP + Air).  相似文献   

Protected areas do not fulfil the wintering habitat needs of the trans-Saharan migratory Montagu’s harrier     

Ruben Limiñana  Alvaro Soutullo  Beatriz Arroyo  Vicente Urios 《Biological conservation》2012,145(1):62-69

Populations of migratory birds can be affected by events happening at both breeding and wintering grounds. The Sahel is a vast region holding a large number of wintering trans-Saharan migratory European birds, and current land-use changes there may represent a threat for these species. We used satellite tracking data from the migratory Montagu’s harrier to evaluate habitat use of the species during the wintering season, and whether the current network of protected areas is effective to provide their habitat needs during that season. We also developed an ecological niche model for the species in Western-Central Sahel to check if the most suitable sites are included within current protected areas. Tracked harriers occupied a large region encompassing a total of eight countries. The most preferred habitats during winter were croplands and some natural vegetation habitats, especially grasslands. Protected areas only covered a small proportion of the overall wintering grounds of tracked harriers and the most suitable areas for the species in Western-Central Sahel. Increasing the extent of preferred natural habitats within protected areas should benefit the conservation of this and probably other insect-eating raptors. However, substantial increases in extent and number of protected areas in sub-Saharan Africa are very unlike to occur. Conservation actions in the region should therefore be mostly focused on improving land use planning and management outside protected areas, specially enhancing agricultural practices to make biodiversity conservation compatible with poverty alleviation. These can be chiefly targeted at an area of <20,000 km² of very suitable habitat for these species.  相似文献   

Suspended sediment dynamics during flushing flows in a large impounded river (the lower River Ebro)     

Alvaro Tena  Damià Vericat  Ramon J. Batalla 《Journal of Soils and Sediments》2014,14(12):2057-2069

Purpose

The aim of this work was to improve the understanding of the spatial and temporal dynamics of suspended sediment transport during flushing flows in a large regulated river, the lower River Ebro (NE Spain).

Materials and methods

Relationships between sediment and discharge (i.e. discharge (Q)–suspended sediment concentrations (SSC)) were examined during six flushing flows using continuous discharge and turbidity records obtained at six monitoring sections distributed along the lower Ebro River for the 2008–2011 period.

Results and discussion

Analyses revealed marked spatial and temporal patterns. At the spatial scale, the Q–SSC relationships were mostly influenced by the different routing velocity of discharge and sediment waves. At the upstream sections, the sediment peak usually preceded peak discharge (i.e. clockwise loop); however, flow routing through the 85-km channel length tends to increase the lag between them, modifying the hysteresis towards counter-clockwise patterns in the downstream direction. At the temporal scale, the season when the artificial releases were performed strongly influenced the sediment availability, with similar-magnitude flushing flows generating higher sediment peaks in autumn than in spring.

Conclusions

These results are of great interest in order to reinforce the flushing flows programme in the lower Ebro River, so as to help achieve the sustainability of the riverine and deltaic ecosystems.  相似文献   

Use of PCR-RFLP to identify Leishmania species in naturally-infected dogs     

de Andrade HM  Reis AB  dos Santos SL  Volpini AC  Marques MJ  Romanha AJ 《Veterinary parasitology》2006,140(3-4):231-238

Tissue imprints on Giemsa stained slides from dogs were used to investigate the presence of Leishmania amastigotes by either optical microscopy (OM) or Polymerase chain reaction (PCR) detection of DNA. Samples from skin, spleen, lymph node, liver and bone marrow from a Leishmaniasis endemic area dogs where Leishmania (Leishmania) chagasi and Leishmania (Viannia) braziliensis are sympatric were studied. Dogs were initially diagnosed by Indirect Immunofluorescence (IIF), as which 39 were IIF positive (≥1:40) and 16 negative. The IIF positive dogs were clinically grouped as symptomatic (n = 15), oligosymptomatic (n = 12) and asymptomatic (n = 12). Although PCR positivity was higher in symptomatic dogs, specially their skin samples, there was no significant difference among clinical groups or organs examined. Ten (62.5%) out of 16 IIF and OM negative animals were positive for PCR in at least one organ. Forty-eight positive PCR amplicons were further submitted to RFLP for Leishmania identification. All dogs were infected with L. (L.) chagasi except one, infected with L. (V.) braziliensis. PCR was more efficient than IIF and OM to diagnose canine visceral Leishmaniasis (CVL), regardless of the organ examined and the clinical form present. The use of PCR together with serology helps determining the extension of sub clinical infection in CVL endemic areas and provides a better estimate of the number of dogs to be targeted for control measures. In conclusion, our data reinforce the need for a specific diagnosis of canine infection in areas where diverse Leishmania species are sympatric and demonstrate that PCR–RFLP can be used to identify Leishmania species in dog tissue imprint stained slides.  相似文献   

Phytoestrogen treatment induces testis alterations in dogs. Potential use in population control     

Perez-Rivero JJ  Martinez-Maya JJ  Perez-Martinez M  Aguilar-Setien A  Garcia-Suarez MD  Serrano H 《Veterinary research communications》2009,33(1):87-95

Dog overpopulation is considered a human health risk; they are the terrestrial vector of rabies and reservoirs for other human diseases. Surgical neutering and intratesticular injections have been used in male dogs. Physiological and morphological alterations in reproductive organs can be induced by phytoestrogens. Our goal was to evaluate the effect of oral coumestrol on dog ejaculates and testis histology. Two groups of 5 healthy adult dogs were used. One coumestrolcontaining biscuit was given once a week for a 4 week period to the experimental group. Ejaculates were obtained and evaluated. After treatment, testis were obtained and processed for histology. Compared to controls, treated dogs have reduced tubules (462 ± 1.4 vs 336 ± 2 μ²), spermatogenic epithelium (49.1 ± 0.01 vs 13.3 ± 0.01 μ²), and lumen opening (891 ± 1.4 vs 530 ± 26.9 μ). Ejaculates from treated animals have increased numbers of abnormal spermatozoa and reduced sperm concentration.  相似文献   

Colombia and Venezuela 1992 wild potato (Solanum sect. Petota) germplasm collecting expedition: taxonomy and new germplasm resources     

David M. Spooner  Raúl Castillo T.  Luis López J.  Ramón Pineda  Raúl León P.  Alvaro Vargas  Maria L. García  John B. Bamberg 《Euphytica》1995,81(1):45-56

Summary We conducted a joint Colombia/United States/Venezuela wild potato (Solanum sect. Petota Dumort.) germplasm collecting expedition in Colombia from June 27–August 24, and in Venezuela from August 17–September 15, 1992. The goals of the expedition were to collect germplasm and study the species boundaries of all of the 23 Colombian and Venezuelan taxa accepted by current taxonomists. We made 128 collections of 16 of these taxa, 96 as true seed collections. We collected the first available germplasm collections of S. cacetanum, S. cuatrecasasii, S. estradae, S. lobbianum, S. orocense, S. paramoense, and S. sucubunense, and obtained germplasm collections of S. neovalenzuelae and S. pamplonense as a germplasm exchange from the Colombian national germplasm collection. We had problems identifying some of our collections, and currently are investigating them for species status and interrelationships. We summarize the state of germplasm collections for Colombia and Venezuela, provide our field data regarding the taxonomy of Colombian and Venezuelan wild potatoes, and provide recommendations for future collecting.  相似文献   

Genetic control of Asian rust in soybean     

Aliny Simony Ribeiro  José Ubirajara Vieira Moreira  Pedro Henrique Braga Pierozzi  Breno Francovig Rachid  José Francisco Ferraz de Toledo  Carlos Alberto Arrabal Arias  Rafael Moreira Soares  Claudia Vieira Godoy 《Euphytica》2007,157(1-2):15-25

The objective of this study was to investigate the genetic mechanisms of soybean resistance to Asian rust (Phakopsora pachyrhizi Syd. & P. Syd). F2 and F3 generations from 15 diallel crosses involving six soybean cultivars, FT-2, EMBRAPA 48, BRS 154, BRS 184, BRS 214, BRS 231, were used to analyze the genetic control of Asian rust resistance in the soybean parents tested. Genetic models were fitted to means and variances of the generations tested in a completely randomized field experiment with 5,700 hill plots. The experiment was spray-inoculated twice with an isolate that was first detected during the 2002/03 season in Mato Grosso (MT) State and presently prevail in Central Brazil, at a six-day interval, on borders rows and on the useful area, respectively, with a 10⁴ spores/ml distilled H₂O suspension. Assessments were made using a diagrammatic scale for disease severity at seven and 39 days after the first detection of Asian rust in the experiments. Evaluations made in the second assessment (39 days) discriminated better between genotypes. Selection at early plant developmental stages may not result in adult resistant plants. Cultivar FT-2, which had presented monogenic resistance to a rust isolated that prevailed in the first two years of rust occurrence in Brazil, showed no resistance to the MT State rust strain used in this experiment, but eleven crosses showed genetic variability for resistance in the second assessment. Soybean rust resistant genes showing predominantly additive effects are dispersed among parents. Narrow sense heritability values ranging from 0.42 to 0.74 at the F3 family level in the second assessment suggested that selection of resistant genotypes is feasible.  相似文献   

Regional habitat conservation priorities for the American crocodile     

John Thorbjarnarson  Frank Mazzotti  Fabio Buitrago  Karen Minkowski  Paulino Ponce  Roberto Soberon  Alvaro Velasco 《Biological conservation》2006,128(1):25-36

The American crocodile is widely distributed in coastal and lowland wetlands in the northern Neotropics. As a result of commercial skin hunting in the 20th century, populations were greatly diminished, but in many areas have initiated a period of recovery since hunting and trade controls were enacted in the 1980s and 1990s. While a great deal of attention has been devoted to regulated commercial use as a management strategy for recovering crocodilian populations, these approaches are limited in their efficacy to deal with issues of habitat loss and fragmentation. Because habitat limitations are expected to be the most critical issue for crocodile conservation in the 21st century, there is an unfulfilled need for alternative strategies that prioritize habitat conservation. Here, we present results of an international effort to identify and prioritize the most critical habitats for this wide ranging species. We quantified information of a group of American crocodile experts and classified 69 areas in eight distinct crocodile bioregions as Crocodile Conservation Units (CCU), the most important areas for the conservation of this species. The relative importance of the CCUs in each bioregion was quantified using an algorithm that weighted factors that the experts considered to be most important for the long term conservation of viable populations of crocodiles. This effort is the initial step in the development of a regional conservation plan for the American crocodile. We identified two bioregions in particular where the creation of protected areas should be given a high priority, the Dry Pacific South America (northern Peru and southern Ecuador) and the Northwest and Central Pacific Mexico.  相似文献   

Diagnostic needle arthroscopy of the scapulohumeral joint in standing sedated horses     

Morgane Pouyet  Alvaro G. Bonilla 《Veterinary surgery : VS》2021,50(1):29-37

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Quambalaria eucalypti found on Eucalyptus in Indonesia     

Marthin Tarigan  Michael J. Wingfield  Yosep M. A. N. Marpaung  Alvaro Durán  Nam Q. Pham 《Forest Pathology》2023,53(5):e12829

The Eucalyptus plantation industry in Indonesia has expanded rapidly during the last few decades. During routine nursery disease surveys, symptoms of a leaf and shoot blight disease were detected on Eucalyptus mother plants. Isolates were obtained from symptomatic tissues and identified using DNA sequence analyses. Phylogenetic analyses showed that the isolates were those of Quambalaria eucalypti. Pathogenicity tests were conducted with isolates of Q. eucalypti on clones of E. pellita and E. grandis × E. pellita hybrids. These resulted in symptoms similar to those observed on naturally infected plants. Eucalyptus genotypes tested showed variation in their susceptibility, highlighting the potential to select and breed for resistance and thus to manage future outbreaks of the disease. This is the first report of the pathogen in Indonesia as well as in Southeast Asia.  相似文献