124 research outputs found

    Advanced active pixel architectures in standard CMOS technology

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    This paper aims at exploring and validating the adoption of standard fabrication processes for the realization of CMOS active pixel sensors, for particle detection purposes. The goal is to implement a single-chip, complete radiation sensor system, including on a CMOS integrated circuit the sensitive devices, read-out and signal processing circuits. A prototype chip (RAPS01) based on these principles has been already fabricated, and a chip characterization has been carried out; in particular, the evaluation of the sensitivity of the sensor response on the actual operating conditions was estimated, as well as the response uniformity. Optimization and tailoring of the sensor structures for High Energy Physics applications are being evaluated in the design of the next generation chip (RAPS02). Basic features of the new chip includes digitally configurable readout and multi-mode access (i.e., either sparse of line-scan readout). © 2005 IEEE

    Quali obiettivi di selezione per fronteggiare i cambiamenti climatici

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    Abstract Climate change (CC) is one of the world’s major concerns. The rise of average temperatures, decrease of rainfalls, and increase of extreme weather events will affect agriculture, including livestock productions, in many areas of the world. Selection for tolerance to adverse weather conditions is one of the tools to mitigate the effects of CC on livestock production. An essential element is the choice of phenotypes. Physiological variables are difficult to measure on a large scale, but precision livestock farming can be of great help in this respect. The use of performance data combined with environmental variables is easier to apply, even if the results are strongly influenced by the mathematical-statistical models used. Given the complexity of the relationships with other phenotypes, resistance to adverse climatic conditions should be included in a selection index aggregated with other productive and functional traits. Genomics will provide a fundamental contribution to the understanding of the genetic determinism of the ability to adapt to climate change. In this context, local breeds are of great importance, as their genetic evolution has been largely driven by adaptation to environmental conditions. The use of genomic selection could speed up genetic progress in selection for tolerance to adverse climatic conditions

    Runs of homozygosity in the Italian goat breeds: impact of management practices in low‑input systems

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    Background Climate and farming systems, several of which are considered as low-input agricultural systems, vary between goat populations from Northern and Southern Italy and have led to different management practices. These processes have impacted genome shaping in terms of inbreeding and regions under selection and resulted in differences between the northern and southern populations. Both inbreeding and signatures of selection can be pinpointed by the analysis of runs of homozygosity (ROH), which provides useful information to assist the management of this species in different rural areas. Results We analyzed the ROH distribution and inbreeding (FROH) in 902 goats from the Italian Goat Consortium2 dataset. We evaluated the differences in individual ROH number and length between goat breeds from Northern (NRD) and Central-southern (CSD) Italy. Then, we identified the signatures of selection that differentiate these two groups using three methods: ROH, ΔROH, and averaged FST. ROH analyses showed that some Italian goat breeds have a lower inbreeding coefficient, which is attributable to their management and history. ROH are longer in breeds that are undergoing non-optimal management or with small population size. In several small breeds, the ROH length classes are balanced, reflecting more accurate mating planning. The differences in climate and management between the NRD and CSD groups have resulted in different ROH lengths and numbers: the NRD populations bred in isolated valleys present more and shorter ROH segments, while the CSD populations have fewer and longer ROH, which is likely due to the fact that they have undergone more admixture events during the horizontal transhumance practice followed by a more recent standardization. We identified four genes within signatures of selection on chromosome 11 related to fertility in the NRD group, and 23 genes on chromosomes 5 and 6 related to growth in the CSD group. Finally, we identified 17 genes on chromosome 12 related to environmental adaptation and body size with high homozygosity in both groups. Conclusions These results show how different management practices have impacted the level of genomic inbreeding in two Italian goat groups and could be useful to assist management in a low-input system while safeguarding the diversity of small populations

    Conservation status and historical relatedness of Italian cattle breeds

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    Abstract Background: In the last 50 years, the diversity of cattle breeds has experienced a severe contraction. However, in spite of the growing diffusion of cosmopolite specialized breeds, several local cattle breeds are still farmed in Italy. Genetic characterization of breeds represents an essential step to guide decisions in the management of farm animal genetic resources. The aim of this work was to provide a high-resolution representation of the genome-wide diversity and population structure of Italian local cattle breeds using a medium-density single nucleotide polymorphism (SNP) array. Results: After quality control filtering, the dataset included 31,013 SNPs for 800 samples from 32 breeds. Our results on the genetic diversity of these breeds agree largely with their recorded history. We observed a low level of genetic diversity, which together with the small size of the effective populations, confirmed that several breeds are threatened with extinction. According to the analysis of runs of homozygosity, evidence of recent inbreeding was strong in some local breeds, such as Garfagnina, Mucca Pisana and Pontremolese. Patterns of genetic differentiation, shared ancestry, admixture events, and the phylogenetic tree, all suggest the presence of gene flow, in particular among breeds that originate from the same geographical area, such as the Sicilian breeds. In spite of the complex admixture events that most Italian cattle breeds have experienced, they have preserved distinctive characteristics and can be clearly discriminated, which is probably due to differences in genetic origin, environment, genetic isolation and inbreeding. Conclusions: This study is the first exhaustive genome-wide analysis of the diversity of Italian cattle breeds. The results are of significant importance because they will help design and implement conservation strategies. Indeed, efforts to maintain genetic diversity in these breeds are needed. Improvement of systems to record and monitor inbreeding in these breeds may contribute to their in situ conservation and, in view of this, the availability of genomic data is a fundamental resource

    Contributi per una flora vascolare di toscana. IX (507-605)

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    Contributions for a vascular flora of Tuscany. IX (507-605). New localities and/or confirmations concerning 98 specific and subspecific plant taxa of Tuscan vascular flora, belonging to 81 genera and 42 families are presented: Alisma, Baldellia (Alismataceae), Chenopodium (Amaranthaceae), Sternbergia (Amaryllidaceae), Bupleurum (Apiaceae), Vinca (Apocynaceae), Muscari, Polygonatum (Asparagaceae), Carlina, Centaurea, Chondrilla, Filago, Pallenis, Tagetes, Tr a - gopogon, Tyrimnus (Asteraceae), Impatiens (Balsaminaceae), Campsis (Bignoniaceae), Cardamine, Iberis, Isatis, Lepidium, Rorippa (Brassicaceae), Humulus (Cannabaceae), Centranthus (Caprifoliaceae), Atocion, Paronychia, Sabulina, Scleranthus (Caryophyllaceae), Euonymus (Celastraceae), Fumana (Cistaceae), Phedimus, Sedum (Crassulaceae), Juniperus (Cupressacesae), Carex, Cyperus, Schoenus (Cyperaceae), Erica (Ericaceae), Euphorbia (Euphorbiaceae), Astragalus, Cytisus, Gleditsia, Lotus, Trifolium, Vicia (Fabaceae), Geranium (Geraniaceae), Philadelphus (Hydrangeaceae), Phacelia (Hydrophyllaceae), Hermodactylus, Iris, Romulea (Iridaceae), Salvia, Ziziphora (Lamiaceae), Gagea, Lilium (Liliaceae), Lindernia (Linderniaceae), Mirabilis (Nyctaginaceae), Nymphaea (Nymphaeaceae), Ligustrum (Oleaceae), Oenothera (Onagraceae), Oxalis (Oxalidaceae), Plantago, Veronica (Plantaginaceae), Armeria (Plumbaginaceae), Eleusine, Festuca, Phleum, Setaria, Stipa, Tragu s (Poaceae), Stuckenia (Potamogetonaceae), Anemonoides, Ranunculus (Ranunculaceae), Reseda (Resedaceae), Aphanes, Cotoneaster, Eriobotrya, Malus, Rosa (Rosaceae), Galium (Rubiaceae), Nicotiana, (Solanaceae). In the end, the conservation status of the units and possible protection of the cited biotopes are discussed

    Contributi per una flora vascolare di Toscana. VIII (440-506)

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    New localities and/or confirmations concerning 67 specific and subspecific plant taxa of Tuscan vascular flora, belonging to 59 genera and 37 families are presented: Alisma (Alismataceae), Amaranthus (Amaranthaceae), Leucojum, Sternbergia, Tristagma (Amaryllidaceae), Aloe (Asphodelaceae), Erigeron, Galinsoga, Hieracium, Rhagadiolus, Silybum, Soliva, Taraxacum (Asteraceae), Impatiens (Balsaminaceae), Berberis (Berberidaceae), Cardamine (Brassicaceae), Opuntia (Cactaceae), Cephalaria, Sixalix, Succisa (Caprifoliaceae), Silene (Caryophyllaceae), Convolvulus, Ipomoea (Convolvulaceae), Aeonium (Crassulaceae), Scirpus (Cyperaceae), Equisetum (Equisetaceae), Euphorbia (Euphorbiaceae), Astragalus, Trifolium (Fabaceae), Quercus (Fagaceae), Crocus (Iridaceae), Juncus (Juncaceae), Utricularia (Lentibulariaceae), Peplis (Lythraceae), Maclura (Moraceae), Nymphaea (Nymphaeaceae), Oenothera (Onagraceae), Anacamptis, Orchis (Orchidaceae), Orobanche (Orobanchaceae), Callitriche, Veronica (Plantaginaceae), Alopecurus, Eleusine, Glyceria, Phleum (Poaceae), Persicaria, Polygonum (Polygonaceae), Groenlandia (Potamogetonaceae), Clematis, Pulsatilla, Ranunculus (Ranunculaceae), Rhamnus (Rhamnaceae), Fragaria, Potentilla, Pyracantha (Rosaceae), Galium (Rubiaceae), Sparganium (Typhaceae), Vitis (Vitaceae). In the end, the conservation status of the units and eventual protection of the cited biotopes are discussed

    Contributi per una flora vascolare di Toscana. VIII (440-506) [Contributions for a vascular flora of Tuscany. VIII (440-506)]

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    Contributions for a vascular flora of Tuscany. VIII (440-506). New localities and/or confirmations concerning 67 specific and subspecific plant taxa of Tuscan vascular flora, belonging to 59 genera and 37 families are presented: Alisma (Alismataceae), Amaranthus (Amaranthaceae), Leucojum, Sternbergia, Tristagma (Amaryllidaceae), Aloe (Asphodelaceae), Erigeron, Galinsoga, Hieracium, Rhagadiolus, Silybum, Soliva, Taraxacum (Asteraceae), Impatiens (Balsaminaceae), Berberis (Berberidaceae), Cardamine (Brassicaceae), Opuntia (Cactaceae), Cephalaria, Sixalix, Succisa (Caprifoliaceae), Silene (Caryophyllaceae), Convolvulus, Ipomoea (Convolvulaceae), Aeonium (Crassulaceae), Scirpus (Cyperaceae), Equisetum (Equisetaceae), Euphorbia (Euphorbiaceae), Astragalus, Trifolium (Fabaceae), Quercus (Fagaceae), Crocus (Iridaceae), Juncus (Juncaceae), Utricularia (Lentibulariaceae), Peplis (Lythraceae), Maclura (Moraceae), Nymphaea (Nymphaeaceae), Oenothera (Onagraceae), Anacamptis, Orchis (Orchidaceae), Orobanche (Orobanchaceae), Callitriche, Veronica (Plantaginaceae), Alopecurus, Eleusine, Glyceria, Phleum (Poaceae), Persicaria, Polygonum (Polygonaceae), Groenlandia (Potamogetonaceae), Clematis, Pulsatilla, Ranunculus (Ranunculaceae), Rhamnus (Rhamnaceae), Fragaria, Potentilla, Pyracantha (Rosaceae), Galium (Rubiaceae), Sparganium (Typhaceae), Vitis (Vitaceae). In the end, the conservation status of the units and eventual protection of the cited biotopes are discussed
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