611 research outputs found
Singularities of affine equidistants: projections and contacts
Using standard methods for studying singularities of projections and of
contacts, we classify the stable singularities of affine -equidistants
of -dimensional closed submanifolds of , for ,
whenever is a pair of nice dimensions.Comment: 18 pages, v2 (minimal changes) agrees with version to appear in
Journal of Singularitie
Reproductive isolation in the Aegean Ophrys omegaifera complex (Orchidaceae)
The orchid genus Ophrys operates a system of sexual deception by which high specificity of pollination is attained. Reproductive isolation in Ophrys mainly rests upon prezygotic isolation mechanisms. The level of genetic separateness of Ophrys taxa with different pollinators is therefore likely determined by the fidelity of pollinators. The present study employs genetic fingerprinting to investigate this in the east Aegean Ophrys omegaifera s.l. complex, also including O. dryis, a west Mediterranean species of this complex. Ophrys fleischmannii, O. basilissa, and the west Mediterranean O. dyris, are found to be well-separated genetic entities whereas O. omegaifera s.str. and the putative hybrid taxon, O. sitiaca, are found to be genetically inseparable across their entire range of co-occurrence. This suggests that specific pollinators have high enough fidelity to act as effective isolating factors in east Aegean O. omegaifera s.l. as a whole, but that the situation in the species pair of O. sitiaca and O. omegaifera is likely to be more comple
An 11th century a.d. burnt granary at La Gravette, south-western France : preliminary archaeobotanical results
International audienceA thick layer of carbonised seeds was encountered in an 11th century a.d. room situated in the seigneurial part of the village of La Gravette. This paper presents the first results of charcoal and seed analyses which give information on the food products stored in the granary and on their arrangement there. Triticum aestivum/durum/turgidum was by far the most important stored crop, while Avena sp., then Hordeum vulgare, Secale cereale, Triticum monococcum and Vitis vinifera were secondary. Weeds were poorly represented. Charcoals were dominated by deciduous Quercus sp., and 11 additional wood taxa were recorded, including especially Fagus sylvatica, Fraxinus sp., Rosaceae, Corylus avellana, Acer campestre and Ulmus sp. According to the charcoal distribution, Quercus and Fagus were probably building materials while most of other taxa would have been used for basketry, wattling or joinery work. In the western part of the granary, naked wheat was stored in bulk. In the eastern part, various crops (at least naked wheat, barley, rye, oat and grape) were stored in small amounts, most of which were probably separated by light wooden structures. The cereal crops had largely been processed and cleaned. The stored products probably represent taxes paid to the lord who owned the granary
Assessment of genetic diversity in maize (Zea mays L.) landraces using inter simple sequence repeat (ISSR) markers
Inter Simple Sequence Repeat (ISSR) markers were used to assess the genetic relationships among 79 landraces and two improved varieties of maize cultivated in Brazil. Nine primers comprising dinucleotides (GA)9, (AT)9, trinucleotides (GTG)6, (TAG)6, and the tetranucleotides (GATA)4, (GACA)4, (CCTA)4, and (GGTA)4 were used for PCR amplifications. From a total of 153 DNA fragments produced, 116 (75.8%) were found to be polymorphics. The dinucleotide motifs (GA)9T and (GA)9C combined with other di-, tri- and tetra-nucleotides produced a greater number of DNA fragments, which suggests a high frequency of the poly GA microsatellite motifs in the maize genome. The UPGMA clustering algorithm associated the varieties into three major groups that were correlated to the endosperm colors and fourteen sub clusters that were mostly related to the flowering time. The results revealed that ISSR markers could be efficiently used to quickly access the genetic variation available in the maize germplasm. The information on genetic similarity among varieties will be useful for selecting the accessions to establish a germplasm bank of maize landraces and to develop breeding programs
Genetic variability in Brazilian Capsicum baccatum germplasm collection assessed by morphological fruit traits and AFLP markers.
<div><p><i>Capsicum baccatum</i> is one of the main pepper species grown and consumed in South America. In Brazil, it is commonly cultivated by family farmers, using mostly the genotypes bishop's hat genotypes (locally <i>cambuci</i>) and red chili pepper (<i>dedo-de-moça</i>). This study had the objective of characterizing 116 <i>C</i>. <i>baccatum</i> accessions from different regions of Brazil, based on morphological fruit descriptors and AFLP (Amplified Fragment Length Polymorphisms) markers. Broad phenotypic variability among the <i>C</i>. <i>baccatum</i> accessions was detected when using morphological fruit descriptors. The Ward modified location model (Ward-MLM) discriminated five groups, based mainly on fruit shape. Six combinations of AFLP primers detected polymorphism in 97.93% of the 2466 identified bands, indicating the high genetic variability in the accessions. The UPGMA coincided with the Bayesian clustering analysis and three large groups were formed, separating the wild variety <i>C</i>. <i>baccatum</i> var. <i>praetermissum</i> from the other accessions. There was no relation between genetic distance and geographical origin of the accessions, probably due to the intense exchange of fruits and seeds between farmers. Morphological descriptors used together with AFLP markers proved efficient in detecting the levels of genetic variability among the accessions maintained in the germplasm collections. These results can be used as an additional source of helpful information to be exploited in <i>C</i>. <i>baccatum</i> breeding programs.</p></div
A Randomized Double-Blind Study Comparing the Efficacy and Safety of Orlistat Versus Placebo in Obese Patients with Mild to Moderate Hypercholesterolemia
INTRODUCTION: Obesity is a chronic disease and a serious health problem that leads to increased prevalence of diabetes, hypertension, dyslipidemia and gallbladder disease.
OBJECTIVE: To evaluate the efficacy of orlistat for weight loss and improved lipid profile compared to placebo in obese patients with hypercholesterolemia, treated over a period of 6 months.
METHODOLOGY: In a 6-month, multicenter (10 centers in Portugal), double-blind, parallel, placebo-controlled study, 166 patients, aged 18-65 years, body mass index (BMI) > or = 27 kg/m2, LDL cholesterol > 155 mg/dl, were randomized to a reduced calorie diet (600 kcal/day deficit) plus orlistat three times a day or placebo. Exclusion criteria included triglycerides > 400 mg/dl, severe cardiovascular disease, uncontrolled hypertension, type 1 or 2 diabetes under pharmacological treatment, and gastrointestinal or pancreatic disease.
RESULTS: The mean difference in weight from baseline was 5.9% (5.6 kg) in the orlistat group vs. 2.3% (2.2 kg) in the placebo group. In the orlistat group 49% of patients achieved 5-10% weight loss and 8.8% achieved > 10%. The orlistat group showed a significant reduction in total and LDL cholesterol, with similar changes for HDL in both treatment groups. The frequency of gastrointestinal adverse events was slightly higher in the orlistat group than in the placebo group, leading to discontinuation in 7 patients.
CONCLUSION: Treatment with orlistat plus a reduced calorie diet for 6 months achieved significant reductions in weight, BMI and lipid parameters
Understanding Interorganizational Learning Based on Social Spaces and Learning Episodes
Different organizational settings have been gaining ground in the world economy, resulting in a proliferation of
different forms of strategic alliances that translate into a growth in the number of organizations that have started
to deal with interorganizational relationships with different actors. These circumstances reinforce Crossan, Lane,
White and Djurfeldt (1995) and Crossan, Mauer and White (2011) in exploring what authors refer to as the
fourth, interorganizational, level of learning. These authors, amongst others, suggest that the process of
interorganizational learning (IOL) warrants investigation, as its scope of analysis needs widening and deepening.
Therefore, this theoretical essay is an attempt to understand IOL as a dynamic process found in
interorganizational cooperative relationships that can take place in different structured and unstructured social
spaces and that can generate learning episodes. According to this view, IOL is understood as part of an
organizational learning continuum and is analyzed within the framework of practical rationality in an approach
that is less cognitive and more social-behavioral
Seagrass and submerged aquatic vegetation (VAS) habitats off the Coast of Brazil: state of knowledge, conservation and main threats
Seagrass meadows are among the most threatened ecosystems on earth, raising concerns about the equilibrium of coastal ecosystems and the sustainability of local fisheries. The present review evaluated the current status of the research on seagrasses and submerged aquatic vegetation (SAV) habitats off the coast of Brazil in terms of plant responses to environmental conditions, changes in distribution and abundance, and the possible role of climate change and variability. Despite an increase in the number of studies, the communication of the results is still relatively limited and is mainly addressed to a national or regional public; thus, South American seagrasses are rarely included or cited in global reviews and models. The scarcity of large-scale and long-term studies allowing the detection of changes in the structure, abundance and composition of seagrass habitats and associated species still hinders the investigation of such communities with respect to the potential effects of climate change. Seagrass meadows and SAV occur all along the Brazilian coast, with species distribution and abundance being strongly influenced by regional oceanography, coastal water masses, river runoff and coastal geomorphology. Based on these geomorphological, hydrological and ecological features, we characterised the distribution of seagrass habitats and abundances within the major coastal compartments. The current conservation status of Brazilian seagrasses and SAV is critical. The unsustainable exploitation and occupation of coastal areas and the multifold anthropogenic footprints left during the last 100 years led to the loss and degradation of shoreline habitats potentially suitable for seagrass occupation. Knowledge of the prevailing patterns and processes governing seagrass structure and functioning along the Brazilian coast is necessary for the global discussion on climate change. Our review is a first and much-needed step toward a more integrated and inclusive approach to understanding the diversity of coastal plant formations along the Southwestern Atlantic coast as well as a regional alert the projected or predicted effects of global changes on the goods and services provided by regional seagrasses and SAV
Complete Genome Sequence of Bifidobacterium longum W11 (LMG P-21586), Used as a Probiotic Strain
We report the complete genome sequence of Bifidobacterium longum W11 (LMG P-21586) isolated from the intestinal microbiota of a healthy man. The analysis of the sequence may provide insights into the microbiological characteristics and the functional activity of this probiotic strain
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