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51.
Abstract: The family Phylloporinidae was introduced in the late 19th century to accommodate a small number of Palaeozoic bryozoan genera characterized by irregularly fenestrated colonies generated by anastomosis of unilaminate branches. Among the first named of these genera were Chasmatopora Eichwald, 1855 and Phylloporina Ulrich in Foerste, 1887. The two names have been variously in fashion, and there has been confusion about whether they are subjective synonyms or are distinct genera. This taxonomic confusion has been due in large part to whether the single species (Retepora angulata Hall, 1847) assigned to Phylloporina in Foerste (1887) or the species that Ulrich intended (Retepora trentonensis Nicholson, 1875) is the type species and also because of lack of sufficient information about Foerste’s material to characterize it well. We here redescribe the pertinent species, erect the new species Chasmatopora foerstei for the species that Foerste incorrectly assigned to Phylloporina angulata (Hall), and suggest that Retepora trentonensis Nicholson be retained as type species of Phylloporina based on prevailing usage, until the issue is settled by the International Commission on Zoological Nomenclature. 相似文献
52.
Background
Homology is a crucial concept in comparative genomics. The algorithm probably most widely used for homology detection in comparative genomics, is BLAST. Usually a stringent score cutoff is applied to distinguish putative homologs from possible false positive hits. As a consequence, some BLAST hits are discarded that are in fact homologous. 相似文献53.
54.
The XI International Rotifer Symposium was held during 11–18 March, 2006 at the National Autonomous University of Mexico Campus Iztacala located at the North Mexico City (Mexico). These triennial international meetings, first organized in Austria by Late Ruttner-Kolisko in September 1976, are gradually becoming the focal point of discussion and collaboration from rotifer workers across the world. The present XI symposium was attended by 125 participants from 20 nations. During this meeting, different themes of rotifer research from morphology to molecular biology were considered. In addition, there were four invited lectures and four workshops covering different themes of the symposium. During the last 30 years, rotifer research has witnessed gradual shift from the conventional morphological taxonomy to molecular and evolutionary systematics. While the basic rotifer ecological studies continue today, applied areas such as ecotoxicology and aquaculture have taken key roles in the recent meetings. The international rotifer meetings provide ample opportunities not only for exchange of ideas and recent research, but also for material and in establishing inter-personal relationships. Over the last 30 years, the number of participants attending the rotifer meetings has increased. 相似文献
55.
Sérgio A Batista Gifone A Rocha Andreia MC Rocha Ivan EB Saraiva Mônica MDA Cabral Rodrigo C Oliveira Dulciene MM Queiroz 《BMC microbiology》2011,11(1):61
Background
Helicobacter pylori infection is one of the most common infections worldwide and is associated with gastric cancer and peptic ulcer. Bacterial virulence factors such as CagA have been shown to increase the risk of both diseases. Studies have suggested a causal role for CagA EPIYA polymorphisms in gastric carcinogenesis, and it has been shown to be geographically diverse. We studied associations between H. pylori CagA EPIYA patterns and gastric cancer and duodenal ulcer, in an ethnically admixed Western population from Brazil. CagA EPIYA was determined by PCR and confirmed by sequencing. A total of 436 patients were included, being 188 with gastric cancer, 112 with duodenal ulcer and 136 with gastritis. 相似文献56.
The respiratory sensation and some routine cardiorespiratory parameters were studied on native Highlanders from the Argentine
Andes and on Lowlanders from Europe, already tested during previous high altitude expeditions. The tests were performed at
various altitude levels from 2688m e.i., the village altitude for Highlanders, to 5600m during an expedition to Mt. Aconcagua
(6990m). At rest, the perception of 4 external inspiratory resistive loads (ranged between 2.5 and 13 cm.H2O.L-1.s) can allow
us to fix by discrimination the sensitivity index P(A) independently of response bias (B) according to Sensory Decision Theory
(SDT). The Andean highlanders did not experience the respiratory sensation at the same limits as the European lowlanders well
adaptated to high altitude. At higher altitudes than their village altitude, their respiratory sensation presented a lower
threshold of perception and a weaker discrimination which might be partly explained by the evolution of some parameters of
their cardio-respiratory function when altitude increased. Indeed, in response to high altitude hypoxia (5600m), they increased
their respiratory frequency and not their minuteventilation or mouth pressure. This chosen ventilatory pattern was opposite
to the one chosen by the Lowlanders and did not allow for sufficient adaptation to a more important altitude hypoxia than
that of their village altitude. In conclusion, the Andean highlanders wellbeing adapted to their village altitude, exhibited
a difficult acclimatization to higher altitudes which might be due to the characteristics of their respiratory sensation.
These results might explain their weak physical performances during ascent to the Mt. Aconcagua summit in spite of special
training. 相似文献
57.
58.
59.
Caren Rodriguez-Medina Craig A Atkins Anthea J Mann Megan E Jordan Penelope MC Smith 《BMC plant biology》2011,11(1):36
Background
Members of the legume genus Lupinus exude phloem 'spontaneously' from incisions made to the vasculature. This feature was exploited to document macromolecules present in exudate of white lupin (Lupinus albus [L.] cv Kiev mutant), in particular to identify proteins and RNA molecules, including microRNA (miRNA). 相似文献60.