1,066 research outputs found
New combinations for two hybrids in Salvia subg. Rosmarinus (Lamiaceae)
New combinations for two hybrids in Salvia subg. Rosmarinus (Lamiaceae
Personal private herbaria: a valuable but neglected source of floristic data. The case of Italian collections today
Today private collections still represent an important source of information as is evident from the available literature, where, in many cases, private collections are mentioned both in floristic and taxonomic/systematic researches. We present a summary of the main information about private herbaria in Italy, whose collections are currently increasing. Based on our survey, we retrieved information on 34 personal herbaria where 156,361 specimens are preserved at present. Piedmont and Tuscany resulted the two Italian regions with the highest number of collections, whereas for 9 regions we obtained no answer. The most represented families resulted Asteraceae and Poaceae, whereas the most represented genera resulted Carex, Trifolium, and Hieracium. Taken all together, these collections rank 16th among the 68 institutional public herbaria officially recognised in Italy
Comparative assessment of reproductive traits across different habitats in the endangered Webb's hyacinth (Bellevalia webbiana Parl.)
To pursue a proper conservation of narrow endemic species, the knowledge of basic reproductive strategies is crucial to plan adequate conservation activities. One of the most evolutionarily relevant and threatened Italian endemic is the Webb’s hyacinth (Bellevalia webbiana Parl.). As the reproductive behaviour of this species and its connection with human impact are currently unknown, the aim of this study was to characterise the reproductive traits of the Webb’s hyacinth in contrasting habitats. All the 5 known richest populations across the species range were investigated. Their reproductive strategies were inferred by measuring
inflorescence height, fruit set, seed set and P/O ratio. Reproductive features varied greatly amongst stands and also in relation to the degree of human disturbance. However, in all cases, seed sets showed low values. P/O values point towards full xenogamy and it is concluded that effective cross-pollination may be the main mode of sexual reproduction in Bellevalia webbiana. The reasons for the low reproductive performances may reside in pollen limitation, Allee effect and/or intrinsic reduced fertility of the species. Given this scenario, conservation efforts for Webb’s hyacinth should focus on maintaining large and relatively dense populations, to guarantee some chance of in situ survival
A morphometric and karyological study of Onobrychis calabrica (Fabaceae), a neglected species endemic to Calabria, S Italy
A morphometric (multivariate and univariate) and karyological study of Onobrychis calabrica Sirj. (Fabaceae), compared to O. alba subsp. echinata (Guss.) P. W. Ball and O. supina (Chaix ex Vill.) DC., was carried out. According to our results, twelve morphological characters clearly support the distinctiveness of O. calabrica. In addition, the latter species is tetraploid with 2n = 4x = 28 chromosomes, whereas the other two taxa are diploid with 2n = 2x = 14 chromosomes. The names O. calabrica and O. handel-mazzettii Sirj. (a heterotypic synonym of O. supina) are lectotypified here. Onobrychis calabrica, a narrow endemic to SE Calabria, S Italy, is here assessed as Critically Endangered CR B1ab(iii)+B2ab(iii) following IUCN Red List categories and criteria
Chromosome numbers for the Italian flora: 2.
In this contribution new chromosome numbers for Italian endemic taxa are presented. It includes 13 chromosome counts for Ornithogalum (Asparagaceae), Anthemis, Carduus, Centaurea, Cirsium, Hieracium, Taraxacum (Asteraceae), Asyneuma (Campanulaceae), Knautia (Caprifoliaceae), Gypsophila (Caryophyllaceae), Linum (Linaceae), Helleborus (Ranunculaceae)
Chromosome numbers for the Italian flora: 2.
In this contribution new chromosome numbers for Italian endemic taxa are presented. It includes 13 chromosome counts for Ornithogalum (Asparagaceae), Anthemis, Carduus, Centaurea, Cirsium, Hieracium, Taraxacum (Asteraceae), Asyneuma (Campanulaceae), Knautia (Caprifoliaceae), Gypsophila (Caryophyllaceae), Linum (Linaceae), Helleborus (Ranunculaceae)
Sarcopenia and vitamin d deficiency in patients with crohn’s disease: Pathological conditions that should be linked together
Sarcopenia is a prevalent condition in patients with Crohn’s disease (CD), representing an independent predictor factor for the development of major postoperative complications. Thus, a proper assessment of the muscle strength, by using different validated tools, should be deemed an important step of the clinical management of these patients. Patients with CD are frequently malnourished, presenting a high prevalence of different macro-and micro-nutrient deficiencies, including that of vitamin D. The available published studies indicate that vitamin D is involved in the regulation of proliferation, differentiation, and regeneration of muscle cells. The relationship between vitamin D deficiency and sarcopenia has been extensively studied in other populations, with interesting evidence in regards to a potential role of vitamin D supplementation as a means to prevent and treat sarcopenia. The aim of this review was to find studies that linked together these pathological conditions
Chromosome numbers for the Italian flora: 1.
In this contribution new chromosome data obtained on material collected in Italy are presented. It includes 15 chromosome counts for Carduus, Crepis, Picris, Taraxacum (Asteraceae), Ceratonia, Lathyrus (Fabaceae), Colchicum (Colchicaceae), Fritillaria (Liliaceae), Petrorhagia (Caryophyllaceae), Potentilla (Rosaceae), Quercus (Fagaceae), Reseda (Resedaceae), and Thymus (Lamiaceae)
Kernel density classification and boosting: an L2 sub analysis
Kernel density estimation is a commonly used approach to classification. However, most of the theoretical results for kernel methods apply to estimation per se and not necessarily to classification. In this paper we show that when estimating the difference between two densities, the optimal smoothing parameters are increasing functions of the sample size of the complementary group, and we provide a small simluation study which examines the relative performance of kernel density methods when the final goal is classification. A relative newcomer to the classification portfolio is “boosting”, and this paper proposes an algorithm for boosting kernel density classifiers. We note that boosting is closely linked to a previously proposed method of bias reduction in kernel density estimation and indicate how it will enjoy similar properties for classification. We show that boosting kernel classifiers reduces the bias whilst only slightly increasing the variance, with an overall reduction in error. Numerical examples and simulations are used to illustrate the findings, and we also suggest further areas of research
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