A comparison of the autecology of Quercus robur L. and Q. pyrenaica Wild.: present habitat in Galicia, NW Spain     

Diaz-Maroto  IJ; Vila-Lameiro  P; Guchu  E; Diaz-Maroto  MC 《Forestry》2007,80(3):223-239

The biotopes occupied by pedunculate oak (Quercus robur L.)and rebollo oak (Quercus pyrenaica Willd.) in Galicia were characterizedusing different parameters, enabling a comparative analysisof its habitats. Thirty-nine plots of pedunculate oak and 40of rebollo oak were inventoried and 25 ecological parameters(physiographic, climatic and edaphic) were measured to describethe biotopes, along with 14 stand parameters to characterizethe structure and the silviculture of these forests; some ofthem were used in previous works about the autecology of bothspecies. Quercus robur was found to occupy a wider range ofecological habitats and their distribution is oceanic; Q. pyrenaicapresents a more Mediterranean phytoclimatic position. The resultsindicated that the distribution of oak forests in Galicia ismore closely related to physiographic and climatic featuresthan to edaphic, because the nature of the substrates that theyoccupy is similar. Analysis of fragility/aggressiveness betweenboth species and chestnut shows that the aggressiveness of bothoaks, mainly pedunculate, was much higher, except at high altitudes,and in areas with a high mean temperature, where rebollo ismore aggressiveness. Comparison of the two Quercus shows formost of the parameters that Q. robur is the more aggressivespecies.  相似文献   

Calcium, diet and fracture risk: a prospective study of 1898 incident fractures among 34 696 British women and men     

Key TJ  Appleby PN  Spencer EA  Roddam AW  Neale RE  Allen NE 《Public health nutrition》2007,10(11):1314-1320

OBJECTIVE: The risk factors for fractures are incompletely understood. An outstanding question concerns the optimal amount of dietary calcium needed to minimise the risk of fracture. DESIGN: We examined the associations of dietary calcium and other nutrients with self-reported fracture risk in a prospective cohort study. Nutrient intakes were estimated using a semi-quantitative food-frequency questionnaire administered at recruitment. SETTING: The UK. Participants: A total of 26 749 women and 7947 men aged 20-89 years. RESULTS: Over an average of 5.2 years of follow-up, 1555 women and 343 men reported one or more fractures, 72% of these resulting from a fall. Among women, fracture risk was higher at lower calcium intakes, with a relative risk of 1.75 (95% confidence interval (CI) 1.33-2.29) among women with a calcium intake of < 525 mg day- 1 compared with women with a calcium intake of at least 1200 mg day- 1 (test for linear trend, P < 0.001). The association of dietary calcium with fracture risk was stronger among women aged under 50 years at recruitment than among women aged 50 and above. Dietary calcium intake was not associated with fracture risk in men. Fracture risk was not related to the dietary intake of any other nutrient examined. CONCLUSION: In this population, women with a low dietary calcium intake had an increased risk of bone fracture, and this association was more marked among younger women than among older women.  相似文献   

Microbial origin of the abdominal swelling affecting farmed larvae of gilt-head seabream, Sparus aurata L.     

J Sedano  I Zorrilla  MA Moriñigo  MC Balebona  A Vidaurreta  MA Bordas  JJ Borrego 《Aquaculture Research》1996,27(5):323-333

The aetiological agents of the abdominal swelling affecting farmed larvae of gilt-head seabream, Sparus aurata L., were studied. Four Vibrio strains were isolated from larvae of S. aurata affected by this disease, and all strains reproduced the disease in healthy larvae under controlled infection experiments, producing a significant increase of the mortality rates compared to the control (non-inoculated larvae). Several enzymatic properties, which can act as .virulence factors, were demonstrated both in the extracellular products (ECPs) and In live cells of the strains tested. Histopathological examinations of the infected fish larvae revealed important changes of the anterior intestine and liver characterized by a marked hyperthrophy of the intestinal epithelium and hepatocytes, and by a separation of the mucosal and submucosal layers in the digestive tube. These histological alterations were associated with the constant presence of cocobacillar bacteria in the anterior intestine and in the liver. However, the precise pathogenic mechanisms of the strains tested have not been completely elucidated yet.  相似文献   

Behaviour of laying hens in cages with nest sites   总被引：2，自引：2，他引：0  

M C Appleby 《British poultry science》1990,31(1):71-80

1. Behavior of ISA Brown hens was compared in cages with and without nest sites provided, to determine the characteristics necessary for such nest sites and whether part of the existing cage area could be modified to form an acceptable nest file. 2. There were 5 treatments: control (C); a wooden surround in one rear corner of the cage (S); a fiberglass rollaway hollow in one rear corner of the cage (H); a hollow and a surround (H/S); a nest box attached to the back of the cage, containing a hollow (N). 3. Use of rollaway hollows was limited, unless they were blocked and wood shavings were added, when 55 to 60% of eggs were laid in them. There were also problems with soiling of hollows. 4. When hollows were blocked, most hens used them in treatments H/S and N, suggesting that substrate and surroundings both contributed to acceptability of nest sites. 5. Pre-laying behaviour in sites within the cage was disturbed and sometimes abnormal. In addition, these sites were not used for other activities, thus limiting the space available. 6. For pre-laying behaviour to be expressed satisfactorily in cages, an additional nesting area, such as a nest box or boxes, is probably necessary.  相似文献   

Sediment Quality in Burlington Harbor,Lake Champlain,U.S.A.     

Lacey  E. M.  King  J. W.  Quinn  J. G.  Mecray  E. L.  Appleby  P. G.  Hunt  A. S. 《Water, air, and soil pollution》2001,126(1-2):97-120

Surface samples and cores were collected in 1993 fromthe Burlington Harbor region of Lake Champlain. Sediment samples were analyzed for trace metals(cadmium, copper, lead, nickel, silver and zinc),simultaneously extracted metal/acid volatile sulfide(SEM-AVS), grain size, nutrients (carbon and nitrogen)and organic contaminants (polycyclic aromatichydrocarbons (PAHs) and polychlorinated biphenyls(PCBs)). The concentrations of cadmium, copper,silver and zinc from the partial sediment digestion ofthe surface samples correlated well with each other(r ²>0.60) indicating that either a commonprocess, or group of processes determined the sedimentconcentrations of these metals. In an analysis of thespatial distribution of the trace metals and PAHs,high surficial concentrations were present in thesouthern portion of the Harbor. The trace metal trendwas strengthened when the concentrations werenormalized by grain size. A sewage treatment plantoutfall discharge was present in the southeasternportion of the Harbor at the time of this study and isthe major source of trace metal and PAH contamination. Evaluation of sediment cores provides a proxy recordof historical trace metal and organic inputs. Thepeak accumulation rate for copper, cadmium, lead, andzinc was in the late 1960s and the peak silveraccumulation rate was later. The greatestaccumulation of trace metals occurred in the late1960s after discharges from the STP began. Subsequentdeclines in trace metal concentrations may beattributed to increased water and air regulations. The potential toxicity of trace metals and organiccontaminants was predicted by comparing contaminantconcentrations to benchmark concentrations andpotential trace metal bioavailability was predictedwith SEM-AVS results. Surface sample results indicate lead,silver, ΣPAHs and ΣPCBs are potentially toxicand/or bioavailable. These predictions were supportedby studies of biota in the Burlington Harborwatershed. There is a clear trend of decreasing PAHand trace metal contaminant concentrations withdistance from the STP outfall.  相似文献   

Sediment Records of Fallout Radionuclides and their Application to Studies of Sediment-Water Interactions     

P.G. Appleby 《Water, air, and soil pollution》1997,99(1-4):573-585

The fallout radionuclides 210Pb and 137Cs are widely used to date environmental records contained in lake sediments. Since the radionuclide records are themselves the outcome of the transformation of atmospheric fallout by mediating transport processes from the catchment, through the water column and post-depositional migration via pore waters, reliable models of these processes are crucial to accurate dating. The large quantities of data on 210Pb and 137Cs in lake sediments accumulated through their widespread dating applications may be used to study transport models. Their advantages as tracers of transport processes include widespread dispersal through the environment, relatively simple and well known input functions, and ease of measurement. One of the principle factors controlling the transport of any species through the water column is its distribution between aqueous and particulate phases. The relatively solubility of 137Cs in the water column is demonstrated by the reduced 137Cs/210Pb inventory ratios in sediments compared to values expected from direct fallout. Using sediment records from a wide range of Cumbrian lakes, calculations based on simple models indicate that the particulate fraction of weapons fallout 137Cs in the water column ranged from 5-22%, and was proportional to the square root of the sedimentation rate (determined by 210Pb). The KD value for weapons 137Cs in the water column is estimated to be in the range 1-2×105 L kg-1. This is comparable with KD values for Chernobyl 137Cs in these lakes (Smith et al. in press) obtained from direct measurements in the water column.  相似文献   

NASA's Living with a Star Initiative     

Karpen JT  Krimigis SM  Appleby JF  Lawler A 《Science (New York, N.Y.)》2000,289(5483):1296

  相似文献   

Extent,Environmental Impact and Long-term Trends in Atmospheric Contamination in the Usa Basin of East-European Russian Arctic     

Solovieva  N.  Jones  V. J.  Appleby  P. G.  Kondratenok  B. M. 《Water, air, and soil pollution》2002,139(1-4):237-260

Sediment cores and surface sediments from fourteen lakes locatedalong three pollution gradients in the Usa basin, north-east European Russia were analysed for diatoms, spheroidal carbonaceous particles, trace metals and water chemistry. At each site past pH was inferred using a diatom-based transfer function and critical loads for sulphur deposition were calculated using a diatom model. Lakes from the Vorkuta transectcurrently experience the highest levels of atmospheric deposition, however, results suggest that at present day sulphurdeposition levels there is no danger of lake acidification at any of the sites, due to their high buffering capacity. The sediment records show that sites from the Inta and Vorkuta transects experienced higher pollution loads 10–30 yr ago, whencoal production and mining were more intensive. There is also evidence that in the Vorkuta area atmospheric deposition mighthave led to the alkalisation of the lakes since diatom floristicchanges and an increase in inferred pH coincide with the periodof peak industrial activity.  相似文献   

Hypertension and blood pressure among meat eaters,fish eaters,vegetarians and vegans in EPIC-Oxford     

Appleby PN  Davey GK  Key TJ 《Public health nutrition》2002,5(5):645-654

  相似文献   

EPIC-Oxford: lifestyle characteristics and nutrient intakes in a cohort of 33 883 meat-eaters and 31 546 non meat-eaters in the UK     

Davey GK  Spencer EA  Appleby PN  Allen NE  Knox KH  Key TJ 《Public health nutrition》2003,6(3):259-269

  相似文献