The decreased competition in expanding versus mature juniper woodlands is counteracted by adverse climatic effects on growth     

Teresa E. Gimeno  Beatriz Pías  Jesús Martínez-Fernández  David L. Quiroga  Adrián Escudero  Fernando Valladares 《European Journal of Forest Research》2012,131(4):977-987

World-wide deforestation is being reversed in Mediterranean continental areas, where abandonment of traditional practises favours the expansion of valuable habitats, like Juniperus thurifera woodlands. We hypothesised that pre-existing trees facilitate establishment in expanding woodlands, whereas in mature woodlands, competition leads to patch disaggregation. We compared the imprint of these processes on growth, demographic and spatial structure of expanding and mature J. thurifera woodlands. We selected plots where we geopositioned, aged and quantified the morphological characteristics of all trees. In the mature woodland, trees arranged in clumps and randomly in the expanding woodland. Competition negatively affected growth, was greater in the mature woodland and led to disaggregation of juvenile clumps. Differences in growth between the mature and the expanding woodland disappeared in climatically unfavourable years, suggesting that adverse climate constrains growth more in expanding than in mature woodlands. We suggest that change in the dispersal agents and a decrease of facilitation underlay differences in spatial patters between the expanding and the mature woodland. Observed effective recruitment in less than 30?years into the expanding woodland evidenced that propagule arrival and sapling survival do not constrain woodland expansion. Furthermore, growth of juveniles established in these new areas is favoured by reduced intra-specific competition. However, we expect growth in expanding woodlands to be negatively impacted by climate change. We conclude that under current global change scenario, conservation of J. thurifera woodlands is favoured by changes in land use, but greater frequency and severity of drier than usual episodes could hamper natural reforestation.  相似文献   

The feasibility of implementing an ecological network in The Netherlands under conditions of global change     

Martha Bakker  Shah Jamal Alam  Jerry van Dijk  Mark Rounsevell  Teun Spek  Adri van den Brink 《Landscape Ecology》2015,30(5):791-804

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Disposition of doramectin milk residues in lactating dairy sheep     

Imperiale FA  Mottier L  Sallovitz JM  Lifschitz AL  Lanusse CE 《Journal of agricultural and food chemistry》2003,51(10):3185-3190

Doramectin (DRM) is a broad spectrum macrocyclic lactone antiparasitic drug not approved for use in dairy animals. However, DRM and other endectocide compounds are widely used extra-label to control endo- and ectoparasites in dairy sheep. The plasma disposition kinetics and the pattern of DRM excretion in milk were characterized following its subcutaneous administration to lactating dairy sheep. DRM concentration profiles were measured in plasma and milk samples after validation of a specific HPLC-based methodology. DRM was detected between 1 h and 30 days post-treatment. DRM concentrations of 0.48 ng.mL(-1) (plasma) and 1.03 ng.mL(-1) (milk) were measured at 30 days post-treatment. DRM was extensively distributed from the bloodstream to the mammary gland, and large concentrations were excreted in milk. The peak concentrations and total amount of DRM recovered in milk (expressed as area under the concentration versus time curve) were 3-fold higher than those measured in plasma; 2.44% of the total DRM dose was excreted in milk. The long persistence of DRM milk residues should be seriously considered before its extra-label use in dairy animals is recommended.  相似文献   

氨气熏蒸对柑橘属果实采后腐烂的控制效果及对抑霉唑杀菌剂效果的影响     

Clara Montesinos-Herrero  Joseph L.Smilanick  J.Steven Tebbets  Spencer Walse  Lluís Palou 《保鲜与加工》2011,(5):55-56

在初始阶段及2 h后分别两次向柠檬和柑橘的贮藏环境中充入3 000μL.L-1的氨气,并在22℃温度条件下熏蒸处理6 h,可有效抑制由指状青霉菌和意大利青霉菌引起的绿霉病和青霉病。虽然熏蒸后很多孢子仍然存活,但这种处理不伤害柑橘,而会造成柠檬外表皮原有伤口区域的颜色变暗。6 000μL.L-1的氨气熏蒸处理能够略加快柠檬果实由绿变黄的进程。意大利青霉菌的孢子萌发对氨气的敏感程度要高于指状青霉菌。在初始阶段及后2 h两次注入6 000μL.L-1的氨气进行熏蒸处理6 h后,大约有30%的指状青霉菌和10%的意大利青霉菌孢子能够萌发。应用氨气熏蒸处理可抑制一种对抑霉唑(IMZ)有较高抗性的指状青霉菌的生长。本文还研究了氨气熏蒸对这种常见的采后杀菌剂的效果的影响。首先将试验果实浸入10 mg.L-1或30 mg.L-1的IMZ中(大约为常用商业用量的10%),然后用1500μL.L-1的氨气熏蒸处理就可以控制这两种病害的发生,并且这种效果的增长量是叠加的,有时具有协同增效作用。这种作用效果的部分原因可能是由于氨气熏蒸影响了pH的大小,而对于中性的IMZ来说,pH的增加能够显著地提高其抗真菌的活性。1 500、3 000、6 000μL.L-1的氨气熏蒸处理能够使柑橘和柠檬果实上已有伤口组织中的pH值从5.9(±0.2)分别增加0.6(±0.3)、0.9(±0.4)和1.3(±0.3)。IMZ可以在柑橘采后马上应用,将刚采收的果实连同盛装容器一起浸入IMZ水溶液中,在果实运抵包装房之后采用氨气熏蒸处理。由于所有包装房中均有乙烯脱绿室,将其改为密封室后可以用于熏蒸处理。总之,氨气能够取代合成杀菌剂或提高IMZ对柑橘属果实采后腐烂的控制效果,尤其是控制对IMZ有耐药力且在柑橘包装房中广泛存在的指状青霉的能力具有很高的价值。  相似文献   

Implementation of chiselling and mouldboard ploughing in soil after 8 years of no-till management in SW, Spain: Effect on soil quality   总被引：2，自引：0，他引：2  

S. Melero  M. Panettieri  E. Madejn  H. Gmez Macpherson  F. Moreno  J.M. Murillo 《Soil & Tillage Research》2011,112(2):107-113

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Suppression of COX-2, IL-1β and TNF-α expression and leukocyte infiltration in inflamed skin by bioactive compounds from Rosmarinus officinalis L     

Mengoni ES  Vichera G  Rigano LA  Rodriguez-Puebla ML  Galliano SR  Cafferata EE  Pivetta OH  Moreno S  Vojnov AA 《Fitoterapia》2011,82(3):414-421

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Diagnostic Challenge     

Jaime Martorell  Adria Melero 《Journal of Exotic Pet Medicine》2013,22(1):85-89

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Inspective consideration in detection of enterobacteria in the blood of normally slaughtered swine     

Giuffrida A  Ziino G  Panebianco A  Cassarà S 《Veterinary research communications》2003,27(Z1):301-303

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Immunohistochemical analysis of the distribution of desmoglein 1 and 2 in the skin of dogs and cats     

Miragliotta V  Coli A  Ricciardi MP  Podestà A  Abramo F 《American journal of veterinary research》2005,66(11):1931-1935

OBJECTIVE: To compare the distribution of desmoglein (Dsg) 1 and 2 in skin specimens obtained from dogs and cats to provide information about the possible role of the density of Dsg 1 and 2 in the localization of lesions attributable to pemphigus foliaceus in these 2 species. SAMPLE POPULATION: Skin biopsy specimens obtained from 4 dogs and 4 cats. PROCEDURE: Biopsy specimens were collected from the muzzle, bridge of the nose, ear, dorsum, abdomen, area adjacent to the teats, and footpads of each animal. Immunohistochemical analysis was performed on formalin-fixed, paraffin-embedded skin samples by use of a biotinylated mouse monoclonal anti-Dsg 1 and 2 antibody raised against bovine muzzle. Color development was performed by use of the streptavidin-biotin-peroxidase method with a chromogenic substrate. RESULTS: Immunohistochemical staining yielded a positive reaction in skin samples obtained from all anatomic sites. The intensity and distribution of staining were related to the number of layers of the stratum spinosum. No differences were detected between samples obtained from dogs and cats. CONCLUSIONS AND CLINICAL RELEVANCE: No differences in intensity of Dsg 1 and 2 antigen were observed in the stratum spinosum between skin samples obtained from dogs and cats. Analysis of this result suggests that factors other than the distribution of Dsg may be responsible for the differences in localization of primary clinical lesions in dogs and cats with pemphigus foliaceus.  相似文献   

Pavlov's Film     

Foà PP 《Science (New York, N.Y.)》1971,173(3997):581

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