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401.
Benthic marine algal flora of the north shore of Prince Edward Island (Gulf of St. Lawrence), Canada
A seaweed community along 60 km of shoreline in the southern Gulf of St. Lawrence has been studied for 5 years. Because of severe ice action along the shores, the algal flora is largely restricted to subtidal levels, which are accessible only during the ice-free months, April to early December. A total of 52 Rhodophyta, 50 Phaeophyta, 19 Chlorophyta and 5 Cyanophyta was identified, mostly occurring between mean low water and 10 m depth. The normally intertidal dominants Focus vesiculosus L. and Chondrus crispus Stackh. flourish at depths of 0–2.5 m and 2.5–5 m, respectively. Chondrus and Furcellaria lumbricalis (Huds.) Lamour. co-dominate the algal benthos at 5–7.5 m, and F. lumbricalis becomes prevalent at 7.5–10 m. Phyllophora truncata (Pallas) A. Zin. and Phyllophora pseudoceranoides (Gmel.) Newr. & A. Tayl. are the main perennials at 10–15 m, and often at 15–20 m as well. Below 15 m, the flora diminishes markedly, and at 20–25 m consists chiefly of Agarum cribrosum (Mert.) Bory, crustose corallines and Polysiphonia urceolata (Lightf. ex Dillw.) Grev. Laminarians other than Chorda occur only as scattered plants or small patches and do not exceed 1 m length. The algal community is relatively undiversified and is especially deficient in green algae. Despite higher surface-water temperatures during summer, the flora is essentially a cold-water one as is indicated by both composition and low R/P and (R+C)/P ratios of 1.06 and 1.45, respectively. 相似文献
402.
Alaria grandifolia is recorded from Nova Scotia for the first time and is briefly compared with A. esculenta from this area. 相似文献
403.
404.
Angela RI Meyrelles Juliana D Siqueira Pamela P dos Santos Cristina B Hofer Ronir R Luiz Héctor N Seuánez Gutemberg Almeida Marcelo A Soares Esmeralda A Soares Elizabeth S Machado 《Memórias do Instituto Oswaldo Cruz》2016,111(2):120-127
This study investigated the rate of human papillomavirus (HPV) persistence,
associated risk factors, and predictors of cytological alteration outcomes in a
cohort of human immunodeficiency virus-infected pregnant women over an 18-month
period. HPV was typed through L1 gene sequencing in cervical smears
collected during gestation and at 12 months after delivery. Outcomes were defined as
nonpersistence (clearance of the HPV in the 2nd sample), re-infection (detection of
different types of HPV in the 2 samples), and type-specific HPV persistence (the same
HPV type found in both samples). An unfavourable cytological outcome was considered
when the second exam showed progression to squamous intraepithelial lesion or high
squamous intraepithelial lesion. Ninety patients were studied. HPV DNA persistence
occurred in 50% of the cases composed of type-specific persistence (30%) or
re-infection (20%). A low CD4+T-cell count at entry was a risk factor for
type-specific, re-infection, or HPV DNA persistence. The odds ratio (OR) was almost
three times higher in the type-specific group when compared with the re-infection
group (OR = 2.8; 95% confidence interval: 0.43-22.79). Our findings show that
bonafide (type-specific) HPV persistence is a stronger predictor for the development
of cytological abnormalities, highlighting the need for HPV typing as opposed to HPV
DNA testing in the clinical setting. 相似文献
405.
406.
G. J. McLachlan 《Biometrical journal. Biometrische Zeitschrift》1980,22(2):125-129
Some numerical results are presented for generalized ridge regression where the additive constants are based on the data. The adaptive estimator so obtained is compared with the least-squares estimator on the basis of mean square error (MSE). It is shown that the MSE of each component of the vector of ridge estimators may be as low as 47.1% of the variance of the corresponding component of the least squares vector or as high as 125.2%. 相似文献
407.
Hydrophobicity and amphiphilicity in protein structure 总被引:5,自引:0,他引:5