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201.
Qinfeng Guo Basil V. Iannone III Gabriela C. Nunez-Mir Kevin M. Potter Christopher M. Oswalt Songlin Fei 《Landscape Ecology》2017,32(2):229-238
Context
Biological invasions are among the greatest global and regional threats to biomes in the Anthropocene. Islands, in particular, have been perceived to have higher vulnerability to invasions. Because of the dynamic nature of ongoing invasions, distinguishing regional patterns from global patterns and their underlying determinants remains a challenge.Objectives
We aim to comparatively examine global versus regional patterns of plant invasions and the possible underlying mechanisms. We also test whether there is a difference in degree of invasion and invasibility between mainland areas and islands.Methods
We compiled and analyzed data from published sources for 100 mainland areas (i.e., regions, countries, states, and provinces) and 89 islands across the globe.Results
We find that (1) the pool of exotic species available intrinsically decreases as area of the land considered increases (at global scale, all is native), thus global invasion patterns assessed by exotic fraction (proportion of exotics) are primarily determined by land area; (2) because “exotic” is defined relative to the borders of the target region, “boundary effects” can result in regional differences in invasion patterns without any ecological processes being involved; and (3) human population density is closely linked to exotic fraction within regions that are defined by a single administrative border.Conclusions
There were clear differences between global and regional patterns of plant invasions. We observed no difference in the exotic fraction-area relationship between mainland areas and islands, supporting what we refer to as the “island-mainland continuum concept” (i.e., no clear separation in the degree of invasion between islands and mainland area with regard to the effects of area). Because of scale-dependency in many observed patterns, future focus should be placed on the links between local, regional, and global invasion patterns.202.
Characterization of a set of common wheat–Hordeum chilense chromosome 7Hch introgression lines and its potential use in research on grain quality traits
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Chromosome 7Hch from Hordeum chilense has potential for improving seed carotenoid content in wheat as it carries a Phytoene synthase 1 (Psy1) gene, which has a major role in this trait. Structural changes in chromosome 7Hch were obtained in common wheat background by crossing the wheat disomic substitution line 7Hch(7D) with a disomic addition line carrying chromosome 2Cc from Aegilops cylindrica in common wheat cv. ‘Chinese Spring’. Rearranged 7Hch chromosomes were cytologically characterized by FISH. A set of 24 molecular markers and the Psy1 gene were used to identify the H. chilense chromosome segments involved in the introgressions. Six structural rearrangements of chromosome 7Hch were identified. They included three homozygous wheat–H. chilense centromeric translocations, one involving the 7HchS arm (T‐7HchS·A/B) and two involving the 7HchL arm (T1‐7HchL·A/B and T2‐7HchL·A/B). In addition, one 7HchS arm deletion, one 7HchL·7HchL isochromosome and one 7HchS telosome were obtained in hemizygous condition. These genetic stocks will be useful for studying the effect of chromosome 7Hch on wheat flour colour. 相似文献
203.
Guilherme Melgao Heluy Leonardo Rocha Vidal Ramos Virgínia Fonseca Pedrosa Cristiane Sarturi Paulo Gustavo Pires Figueiredo Letícia Gabriela Poblete Vidal Igor de Fiuza Frana Marcelo Maia Pereira 《Aquaculture Research》2020,51(8):3237-3243
The present study was undertaken to examine the effects of oregano essential oil on the growth performance, blood glucose levels, body composition and intestinal morphometry of Nile tilapia reared in salinized water at 10 g/L for 64 days. The experiment was set up as a completely randomized design with five treatments and four replicates, in which a control diet and four diets containing increasing concentrations of oregano essential oil (0.75, 1.5, 2.25 and 3.0 g/kg) were tested. The best results for the growth parameters were obtained with the oregano essential oil inclusion level of 0.75 g/kg, but did not differ (p > .05) from inclusion levels of 0.0, 2.25 and 3.0 g/kg. Conversely, the treatment including the oil level of 1.5 g/kg was the only one to produce significantly (p < .05) lower results. The body composition and blood glucose were not significantly affected. Intestinal morphometry analysis revealed a significant effect on villus length, which increased with the proportion of oregano essential oil added to the diet; accordingly, the inclusion level of 3.0 g/kg provided the best results for this variable. Therefore, the addition of oregano essential oil at 3.0 g/kg in the diet of Nile tilapia cultured in salinized water may act as a stimulant to intestinal villus development and, consequently, as a growth promoter. 相似文献
204.
Jenny Rodríguez Yuri Espinosa Gabriela Cárdenas Samuel Stern 《Aquaculture (Amsterdam, Netherlands)》2007,273(4):405-415
The effect of the inclusion of probiotics (Vibrio alginolyticus) and β-1,3/1,6-glucans in Penaeus vannamei larviculture was evaluated by measuring the immune response and survival of shrimp juveniles subjected to white spot syndrome virus (WSSV) challenge tests (per os) and pond culture. Treatments were designed to contrast the probiotic factor (inclusion vs non-inclusion) and β-1,3/1,6-glucans supplementation in various larvae stages; starting from early stage (Zoea II), to middle stage (PL 12), late stage (15 days pre-challenge) or non-supplemented. In larviculture, the highest survival was obtained in animals treated with β-1,3/1,6-glucans from Zoea II. The use of probiotics enhanced survival during the first 0-52 h post-WSSV challenge period. During 56-156 h post-WSSV challenge period, interactions were observed between β-1,3/1,6-glucans × time and β-1,3/1,6-glucans × time × probiotics. Significant differences in final survival rates between treatments were not observed. In the second WSSV challenge, immune parameters were analysed. Significant interaction between probiotics and β-1,3/1,6-glucans was observed for plasmatic protein (PP) concentration, super oxide anion (O2−) generation, antibacterial activity (AA), and total haemocyte count (THC). The use of probiotics in larviculture had a negative effect on the PP, but increased the AA and THC, while β-1,3/1,6-glucans had a negative effect on the O2− generation. The most relevant results were obtained from treatments T2 (probiotics in larviculture, β-1,3/1,6-glucans from Z II) and T4 (probiotics in larviculture, β-1,3/1,6-glucans 15 days before challenge). Treatment T2 presented the highest survival rate in larviculture. After WSSV infection, the animals of this treatment displayed resistance to the virus, a strong AA and increase of THC. Treatment T4 increased the amount of PP, increased the O2− generation and THC. Histological analysis showed that the animals of treatment T2 and T4 were able to limit the spread of the virus during the first hour after challenge with WSSV. The survivors from treatments T2 and T4 had a high THC, accompanied by a lack of white spot disease (WSD) injuries. A bioassay was carried out under farm conditions during the warm-rainy season using larvae from treatments T2 and T4. The animals were stocked at 18 animals/m2 in earth ponds of 0.20 ha (three ponds/larvae kind). WSD outbreak was not detected, and the survival was significantly higher in ponds stocked with larvae from treatment T4 (70 ± 3%) than in ponds stocked with larvae from treatment T2 (49 ± 9%). 相似文献
205.
206.
207.
Mendelson JR Lips KR Gagliardo RW Rabb GB Collins JP Diffendorfer JE Daszak P Ibáñez D R Zippel KC Lawson DP Wright KM Stuart SN Gascon C da Silva HR Burrowes PA Joglar RL La Marca E Lötters S du Preez LH Weldon C Hyatt A Rodriguez-Mahecha JV Hunt S Robertson H Lock B Raxworthy CJ Frost DR Lacy RC Alford RA Campbell JA Parra-Olea G Bolaños F Domingo JJ Halliday T Murphy JB Wake MH Coloma LA Kuzmin SL Price MS Howell KM Lau M Pethiyagoda R Boone M Lannoo MJ Blaustein AR Dobson A Griffiths RA 《Science (New York, N.Y.)》2006,313(5783):48
208.
Cesar Antonio Sepúlveda‐Quiroz Emyr Saul Pea‐Marín Alfredo Prez‐Morales Rafael Martínez‐García Carina Shianya Alvarez‐Villagomez Claudia Ivette Maytorena‐Verdugo Susana Camarillo‐Coop Paula Gabriela Vissio Daniela Prez Sirkin Dariel Tovar‐Ramírez Mario Galaviz Carlos Alfonso lvarez‐Gonzlez 《Aquaculture Research》2021,52(1):37-50
Supplementary fructooligosaccharides (FOS) were evaluated on growth, survival, gut morphology, digestive enzyme activity and expression of intestinal barrier genes in tropical gar (Atractosteus tropicus). Four treatments were designed to include FOS (5, 10, 15 and 20 g/Kg) and were compared with a control (0 g/Kg) and the current commercial trout diet. Ten fish were stocked (0.25 ± 0.01 g and 4.2 ± 0.4 cm total length) per experimental unit by triplicate in a 45‐day experiment. Fish fed with 5 and 10 g/Kg of FOS had the highest average weight and total average length. Fish fed 5 g/Kg FOS showed the best growth indexes (absolute weight gain: 2.16; specific growth rate: 4.96; and feed conversion rate: 1.23) and survival (96.66%) and also had the highest acid protease, chymotrypsin and leucine aminopeptidase activities. Fish fed 5 g/Kg FOS had a high absorption area and accumulation of lipids in the liver. Finally, relative overexpression of occluding (occ), nucleotide‐binding oligomerization domain‐2 (nod2) and mucin 2 (muc2) was detected in fish fed 10 and 15 g/Kg FOS. The supplementation between 5 and 10 g/Kg FOS in diets for A. tropicus juveniles could be beneficial for growth, digestive enzyme activities, gut morphology and intestinal barrier function. 相似文献
209.
Montel Mendoza G Pasteris SE Ale CE Otero MC Bühler MI Nader-Macías ME 《Research in veterinary science》2012,93(3):1160-1167
The cultivable microbiota of skin and cloaca of captive Lithobates catesbeianus includes microorganisms generally accepted as beneficial and potentially pathogenic bacteria. In order to select a group of potentially probiotic bacteria, 136 isolates were evaluated for their surface properties and production of antagonistic metabolites. Then, 11 lactic acid bacteria (LAB) strains were selected and identified as Lactobacillus plantarum, Lb. brevis, Pediococcus pentosaceus, Lactococcus lactis, L. garvieae and Enterococcus gallinarum. Studies of compatibility indicate that all the strains could be included in a multi-strain probiotic, with the exception of Ent. gallinarum CRL 1826 which inhibited LAB species through a bacteriocin-like metabolite. These results contribute to the design of a probiotic product to improve the sanitary status of bullfrogs in intensive culture systems, to avoid the use of antibiotics and thus to reduce production costs. It could also be an alternative to prevent infectious diseases during the ex situ breeding of amphibian species under threat of extinction. 相似文献
210.
Calzada-Nova G Husmann RJ Schnitzlein WM Zuckermann FA 《Veterinary immunology and immunopathology》2012,148(1-2):116-125
The abilities of the modified-live Prime Pac (PP) strain of porcine reproductive and respiratory syndrome virus (PRRSV), propagated in either traditional simian cells (MARC-145) or in a novel porcine alveolar macrophage cell line (ZMAC), to confer pigs protection against subsequent PRRSV challenge were compared. Eight week-old pigs were injected with PP virus grown in one of the two cell types and then exposed 4 weeks later to the "atypical" PRRSV isolate NADC-20. Control animals were similarly challenged or remained PRRSV-na?ve. While the average adjusted body weight (aabw) of the strict control group increased 22% by 10 days post challenge (pc), this value for the non-vaccinated, challenged group dropped 4%. In contrast, prior immunization with PP virus, regardless of its host cell source, ameliorated this effect by affording a >9% rise in aabw. Likewise, nearly equivalent protection was extended to both groups of vaccinates in regards to the temporal elimination of their pc clinical distress and viremia. However, the PP virus propagated in ZMAC cells appeared to be more efficacious since four of the six pigs receiving this biologic cleared the challenge virus from the their lungs by 10 days pc as compared to only one member of the other vaccinated group. Notably, the predominant quasispecies in the ZMAC cell-prepared PP virus stock contained a highly conserved N-glycosylation site at position 184 in its glycoprotein 2 while this entity was underrepresented in the MARC-145 cell grown biologic. Since glycoprotein 2 is involved in infectivity, such additional glycosylation may enhance virus replication in porcine alveolar macrophages. 相似文献