Literatura académica sobre el tema "Dati altissima frequenza"

AbstractLarvae of the gall-inducing moth Gnorimoschema gallaesolidaginis (Riley) (Lepidoptera: Gelechiidae) attack ramets of Solidago altissima L. and S. gigantea Aiton (Asteraceae), initiating stem galls early in ramet growth. We examined the relationship between ramet size (as an indicator of plant vigour) and galling rate over 3 years at a field site in Toronto, Ontario, Canada. We marked Solidago ramets along line transects, measured their stem diameter, and recorded their fate (galled or ungalled) during the season. For S. altissima, galls were numerous enough for analysis in 2 years, and the frequency of galling increased monotonically with ramet stem diameter in both years. For S. gigantea, galls were numerous enough for analysis in all 3 years, but attack rate - stem diameter relationships were complex. In 2004 the galling frequency peaked at intermediate stem diameter, but in 2005 the galling frequency increased monotonically with stem diameter (and in 2006 the nonsignificant trend was similar). Overall, our data are most consistent with the plant-vigour hypothesis, but the 2004 data for S. gigantea lend some support to the suggestion that herbivore attack might sometimes be most intense on intermediate-sized modules.

In the context of global change, the integration of non-native tree (NNT) species into European forestry is increasingly being discussed. The ecological consequences of increasing use or spread of NNTs in European forests are highly uncertain, as the scientific evidence is either constraint to results from case studies with limited spatial extent, or concerns global assessments that lack focus on European NNTs. For either case, generalisations on European NNTs are challenging to draw. Here we compile data on the impacts of seven important NNTs (Acacia dealbata, Ailanthus altissima, Eucalyptus globulus, Prunus serotina, Pseudotsuga menziesii, Quercus rubra, Robinia pseudoacacia) on physical and chemical soil properties and diversity attributes in Europe, and summarise commonalities and differences. From a total of 103 publications considered, studies on diversity attributes were overall more frequent than studies on soil properties. The effects on soil properties varied greatly among tree species and depended on the respective soil property. Overall, increasing (45%) and decreasing (45%) impacts on soil occurred with similar frequency. In contrast, decreasing impacts on biodiversity were much more frequent (66%) than increasing ones (24%). Species phylogenetically distant from European tree species, such as Acacia dealbata, Eucalyptus globulus and Ailanthus altissima, showed the strongest decreasing impacts on biodiversity. Our results suggest that forest managers should be cautious in using NNTs, as a majority of NNT stands host fewer species when compared with native tree species or ecosystems, likely reflected in changes in biotic interactions and ecosystem functions. The high variability of impacts suggests that individual NNTs should be assessed separately, but NNTs that lack European relatives should be used with particular caution.

Notulae Scientia Biologicae (http://www.notulaebiologicae.ro), Issue 2, Volume 12, 2020: The papers published in this issue represent interesting novelties in different topics of life science. Among the exciting researches, we invite readers to find news about: evaluation of phytochemical constituents and in vitro antimicrobial activities of leaves extracts of Calotropis procera against certain human pathogens; in vitro anti-urease, antioxidant, anticholinesterase, cytotoxic and in vivo anti-inflammatory potential of Satureja cuneifolia; impact of essential oils of clove Syzygium aromaticum in rats exposed to stress by nickel; young capitulum as important explant in in vitro mass propagation of gerbera (Gerbera jamesonii); a comparative study between temporary immersion system and semi-solid cultures on shoot multiplication and plantlets production of two Moroccan date palm (Phoenix dactylifera L.) varieties in vitro; effect of pretreatments on germination of seeds of the timber plant, Terminalia ivorensis and Mansonnia altissima; abundance, frequency and distribution pattern of tree species in recorded forest area of Western Himalaya; role of active transport of potassium to leaves in the mechanisms of tolerance to salinity in common bean (Phaseolus vulgaris L.).

The aim of this study was to analyse the species composition, structures, and regeneration of woody plant species and the impacts of site factors on the natural regeneration of tree species in four study sites of MFBR. The vegetation data were collected systematically in 140 plots with the size of 400 m2 for trees; 25 m2 for seedlings, saplings, shrubs, and lianas; and 1 m2 for herbs. Individual tree and shrub DBH ≥ 5 cm were measured and counted. The diameter at breast height (DBH), frequency, basal area, importance value index (IVI), and density were used for vegetation structure description and regeneration. A total of 158 plant species belonging to 115 genera, 56 families, and 80 species (51%) trees, 26 (16%) shrubs, 19 (12%) herbs, and 33 (21%) lianas were identified and recorded. The most dominant families were Euphorbiaceae, Rubiaceae, and Moraceae, each represented by 13 species (7.4%), 12 species (6.8%), and 10 species (5.7%), respectively. The tree densities varied from 1232 to 1478 stem ha−1, sapling density 176.8 to 708.7 stem ha−1, and seedling density 534.7 to 1657.5 stem ha−1, with an average basal area of 63.6 m2 in the study sites. Dracaena afromontana was the most frequent woody species in the MFBR occurring in 90% followed by Celtis zenkeri (65%) and Pouteria altissima (62.5%). The regeneration status of all the woody plant species was categorised as “not regenerate” (9.6%), “poor” (30.7%), “fair” (59.5%), and “good” (10.8%) in all sites. The correlation result between natural regeneration and site factors revealed both positive and negative relationships. However, the main threat to the biosphere reserve is illegal logging for different purposes. Therefore, awareness creation on sustainable forest management, utilisation, conservation of priority species, and livelihood diversification to the local community and encouraging community and private woodlot plantation in the transitional zone of biosphere reserves are recommended.

L'eziologia della disabilitŕ cognitiva grave č molto complessa, tanto che la causa di questa condizione clinica rimane ancora oggi non identificabile nel 40% circa dei casi. L'inquadramento diagnostico č perň un'esigenza concreta delle famiglie, per tentare di avere piů informazioni possibili sulla prognosi della patologia, sulle possibilitŕ e metodi terapeutici piů appropriati, sui rischi di ricorrenza familiare. I metodi utilizzati per l'inquadramento diagnostico sono di tipo clinico, strumentale e laboratoristico citogenetico-molecolare. Dal punto di vista clinico l'approccio prevede la ricostruzione dell'anamnesi familiare, la raccolta di dati sul decorso della gravidanza, sul periodo neonatale e sulla storia clinica dalla nascita al momento dell'osservazione. Si stima che il 4-35% (in media 15%) dei casi di disabilitŕ cognitiva sia riconducibile ad eziologia cromosomica. Le tecniche di citogenetica molecolare sono progressivamente migliorate negli ultimi anni, con la possibilitŕ di aumentare la sensibilitŕ di diagnosi per le sindromi da microanomalia cromosomica (con la tecnica CH-Array). La sindrome dell'X fragile costituisce una delle piů frequenti cause di disabilitŕ cognitiva nei soggetti di sesso maschile, specialmente nei casi a ricorrenza familiare della patologia. Il numero delle sindromi monogeniche associate a disabilitŕ cognitiva č altissimo, e si tratta sempre di patologie singolarmente rare. In questo ambito č importante saper identificare caratteristiche cliniche che possano orientare verso una patologia specifica, allo scopo di poter ipotizzare una diagnosi clinica ed eventualmente mirare i test genetici nei casi di sindromi ad eziologia attualmente nota. Sono utili, in questo ambito, il riscontro di dismorfie particolari orientative per una sindrome specifica, la caratterizzazione anatomica delle malformazioni associate o l'eventuale presenza di epilessia, la definizione di un fenotipo comportamentale e cognitivo specifico. Č importante anche la rivalutazione clinica nel tempo, per cogliere segni di significato diagnostico che possono comparire in etŕ diverse della vita di un bambino.

Within the last decade the study of phenology has taken on new importance because of its contribution to climate-change research. However, phenology data sets spanning many years are rare in the tropics, making it difficult to evaluate possible responses of tropical communities to climate change. Here we use two data sets (1970–1983 and 1990–2002) to describe the fruiting patterns of the tropical tree community in Kibale National Park, Uganda. To address variation in spatial patterns, we describe fruiting over 2–3 y among four sites each separated by 12–15 km. Presently, the Kibale region is receiving c. 300 mm more rain than it did at the start of the century, droughts are less frequent, the onset of the rainy season is earlier, and the average maximum monthly temperature is 3.5 °C hotter than it was 25 y ago. The 1990–2002 phenology data illustrated high temporal variability in the proportion of the populations fruiting. Interannual variation in community-wide fruit availability was also high; however, the proportion of trees that fruited has increased over the past 12+y. At the species level a variety of patterns were exhibited; however, a number of the most common species currently rarely fruit, and when they do, typically <4% of the individuals take part in fruiting events. Combining the data set from 1990 to 2002 with that from 1970 to 1983 for specific species again reveals an increase in the proportion of trees fruiting between 1990 and 2002; however, the proportion of the populations fruiting decreased during the earlier period. When one examines particular species over this whole period a variety of patterns are evident. For example, Pouteria altissima exhibited a relatively regular pattern of fruiting during the 1970s; however, it rarely fruited in the 1990s. Contrasting phenological patterns at four sites revealed that at the community level the fruiting patterns of only one of the six pair-wise site combinations were correlated. Relationships between rainfall and fruiting were variable among sites. Contrasting changes in fruiting patterns over the 30 y with differences among the four sites varying in rainfall, suggests that the changes observed in fruiting may be due to climate change. Responses to this climate change are likely complex and will vary among species. However, for some species, current conditions appear unsuitable for fruiting.

AbstractPaukova Ž.: Invasive plant species in the three microregions of Nitra region, south-west Slovakia. Ekologia (Bratislava), Vol. 32, No. 2, p. 262-266, 2013. Alien plant species were recorded by field survey in three selected microregions (submontane in district Zlate Moravce, hilly in district Nitra and lowland in districts Nove Zamky) in Nitra region, SW Slovakia in 2011. In the microregions totally 19 invasive neophytes were recorded. The most frequent and abundant species were the following: Ailanthus altissima, Ambrosia artemisiifolia, Conyza canadensis, Fallopia x bohemica, Helianthus tuberosus, Iva xanthiifolia, Negundo aceroides, Robinia pseudoacacia, Solidago canadensis and Stenactis annua. On the basis of the data we can preliminary conclude that the number of species and the number of localities in the southern lowland microregion were almost twice higher than those in the northern hilly region.

Gli autori riportano i più recenti dati di letteratura scientifica relativi alle più frequenti complicanze neonatali dell’induzione della gravidanza soprattutto con le recenti tecniche di riproduzione assistita IVF e ICSI. Gli autori si soffermano sulla aumentata incidenza di malformazioni congenite nei neonati da tecniche di fecondazione assistita, in particolare nei neonati da gravidanza indotta con ICSI. Inoltre gli autori si soffermano sulla eziopatogenesi di tale aumentata incidenza di malformazioni congenite, collegata verosimilmente sia alla tecnica in sé, in special modo alla ICSI più invasiva della IVF, che alle cause della sterilità di coppia.Vengono poi considerate altre problematiche neonatali collegate alle tecniche di riproduzione assistita, in particolare alle ICSI, come l’aumento delle anomalie genetiche e cromosomiche, come le delezioni del cromosoma Y, spesso ereditate dal padre affetto da oligo-azoospermia e l’aumentata incidenza di sindromi da interferenza con l’imprinting genomico. Infine gli autori si soffermano su alcune problematiche di bioetica, come l’importanza degli interventi di tipo preventivo e di tipo terapeutico non sostitutivi dell’atto coniugale per risolvere molte cause dell’infertilità di coppia, la problematica relativa agli embrioni in esubero come conseguenza delle ART, il rapporto costi/benefici applicato alle ART che pende pesantemente dalla parte dei costi altissimi per la salute della madre e del nascituro e sul ruolo del medico che aiuta e non stravolge con metodi sostitutivi l’atto coniugale finalizzato al processo procreativo. ---------- The authors refer to the recent scientific literature concerning the most frequent neonatal complications of the induced pregnancy especially after the recent techniques of assisted reproduction IVF and ICSI. The authors are interested in the increased incidence of congenital malformations in infants born from assisted reproductive technology, especially in infants born after the ICSI technique. Furthermore, the authors are very interested in the etiology of this increased incidence of congenital malformations, probably connected both to the technique in itself, especially for the more invasive ICSI, that couple’s infertility. Then the authors consider other neonatal problem related to the ICSI technique: the increase of genetic and chromosomal abnormalities, as chromosome Y deletion, often inherited from the father suffering from oligo-azoospermia and the increased incidence of genomic imprinting’ syndromes. Finally the authors are concerned about some issues in bioethics, such as the importance of preventive interventions and the types of therapy that cannot replace the conjugal act to resolve a lot of causes of infertility; the problem of the surplus embryos, the cost/benefit analysis applied to ART hanging heavily on the side of a very high cost to the health of mother and unborn child and the role of the doctor who helps and could not distort with alternative methods, the conjugal act designed for the procreation.

La tesi affronta tre diverse problematiche relative alla modellazione della volatilià finanziaria utilizzando dati ad altissima frequenza. This thesis is composed of three different essays, all related to the issue of financial volatility modeling with ultra-high frequency data.