473 research outputs found

    Diaphragmatic hernia following oesophagectomy for oesophageal cancer – Are we too radical?

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    Background: Diaphragmatic herniation (DH) of abdominal contents into the thorax after oesophageal resection is a recognised and serious complication of surgery. While differences in pressure between the abdominal and thoracic cavities are important, the size of the hiatal defect is something that can be influenced surgically. As with all oncological surgery, safe resection margins are essential without adversely affecting necessary anatomical structure and function. However very little has been published looking at the extent of the hiatal resection. We aim to present a case series of patients who developed DH herniation post operatively in order to raise discussion about the ideal extent of surgical resection required. Methods: We present a series of cases of two male and one female who had oesophagectomies for moderately and poorly differentiated adenocarcinomas of the lower oesophagus who developed post-operative DH. We then conducted a detailed literature review using Medline, Pubmed and Google Scholar to identify existing guidance to avoid this complication with particular emphasis on the extent of hiatal resection. Discussion: Extended incision and partial resection of the diaphragm are associated with an increased risk of postoperative DH formation. However, these more extensive excisions can ensure clear surgical margins. Post-operative herniation can be an early or late complication of surgery and despite the clear importance of hiatal resection only one paper has been published on this subject which recommends a more limited resection than was carried out in our cases. Conclusion: This case series investigated the recommended extent of hiatal dissection in oesophageal surgery. Currently there is no clear guidance available on this subject and further studies are needed to ascertain the optimum resection margin that results in the best balance of oncological parameters vs. post operative morbidity

    Environmental improvement and conservation of useful pastures for wild herbivores in a Regional Park on the Apennines mountains

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    In order to investigate some effects of the environmental management with faunistic purpose on pastures located on the Apennines mountains, in open areas subjected to bracken fern (Pteridium aqulinum) infestation, samples of vegetation were taken for three years on an open area in the Regional Park of "Laghi di Suviana e Brasimone" (BO). Experimental samples, taken before and after the agronomical works, showed the effects of the pasture improvement on botanical composition, richness and biodiversity. The agronomical pasture management produced a considerable decrease in bracken density and an increase on biodiversity, and the final average value of the Pastoral Value index was quadruplicate. These results confirmed the effectiveness of the actions carried out and the importance of maintaining a continuous programme of pasture management through annual clearing of vegetation

    Use of Annual Self-Reseeding Legumes in an Oak Forest in Central Italy

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    A trial has been carried out for three years in an oak coppice geometrically thinned out of Mediterranean Central Italy, about the functioning of a pastoral system made by four different resources: native pasture, subterranean clover (Trifolium brachycalycinum Katzn. et Morley) in pure stand, strips thinned out and firebreaks improved with oversown subclover, all grazed by sheep. Subclover increased the forage yield and improved the palatabilty of the pasture and the regularity of grazing; the higher biomass intake by animals reduced the quantity of dried biomass in summer and contributed to keep low either fire hazards or flame diffusion speed. Data underlined the importance of deferred grazing and of the combination of different native or improved resources on the seasonal distribution of production and animal intake

    Feeding evaluation of spontaneous species used by wild ungulates

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    Abandonment of traditional agricultural practices can produce remarkable effects on land use and on the vegetal composition of marginal areas. This is particularly true in the once grazed zones in the mountain environments, that are now affected by encroachment of shrubby vegetation. The conservation of these open areas and the preservation of a correct ratio pasture/wood are of extremely importance for wild animals. In this note we describe the effectiveness of agronomical intervention carried out to enhance pasture quality in a protected area of central Italy. Data collection concerned botanical composition, floristic richness and biodiversity of vegetation, before and after the intervention efforts. Moreover, data on utilization of single species were collected in order to evaluate the real consumption of each plant species by wild animals. Results confirmed the efficiency of the improvement of the studied area in terms of botanical composition and of pastoral value and they provided useful indications about the actual utilization of non forage plants by wild ungulates

    Secure communications based on discrete time chaotic systems

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    Attosecond electron spectroscopy using a novel interferometric pump-probe technique

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    We present an interferometric pump-probe technique for the characterization of attosecond electron wave packets (WPs) that uses a free WP as a reference to measure a bound WP. We demonstrate our method by exciting helium atoms using an attosecond pulse with a bandwidth centered near the ionization threshold, thus creating both a bound and a free WP simultaneously. After a variable delay, the bound WP is ionized by a few-cycle infrared laser precisely synchronized to the original attosecond pulse. By measuring the delay-dependent photoelectron spectrum we obtain an interferogram that contains both quantum beats as well as multi-path interference. Analysis of the interferogram allows us to determine the bound WP components with a spectral resolution much better than the inverse of the attosecond pulse duration.Comment: 5 pages, 4 figure

    Butterflies as bioindicators of metal contamination

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    Anthropogenic trace metal contamination has significantly increased and has caused many hazardous consequences for the ecosystems and human health. The Terni basin valley (Central Italy) shows a heavy load of pollutants from industrial activities, while the characteristic orography structure of the valley favours air stagnation, thus limiting air pollution dispersal. The present study conducted in 2014 aimed to determine the concentration of ten metals in five species of butterflies at nine sites in the Terni valley along a 21-km-long transect, including both relatively pristine and industrial areas. At sites where soil contamination was high for a given metal, such as for chromium as in the case of site 4 (the closest to the steel plant) and for lead as in the case of site 2 (contaminated by a firing range), higher levels of contamination were observed in the tissues of butterflies. We found a correlation between soil contamination and the concentration of Cr, Al and Sr in the tissues of some species of butterflies. The sensitivity to contamination differed among the five species; in particular, Coenonympha pamphilus was generally the species that revealed the highest concentrations of all the ten trace metals at the sites closer to the industrial area. It is known that C. pamphilus is a sedentary species and that its host plants are the Poaceae, capable of accumulating high quantities of metals in their rhizosphere region, thus providing the link with soil contamination. Therefore, monitoring the metal concentration levels in butterflies might be a good indicator and a control tool of environmental quality, specifically in areas affected by high anthropogenic pollution loads linked to a specific source

    Uncertainties in Theoretical HeI Emissivities: HII Regions, Primordial Abundance, and Cosmological Recombination

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    A number of recent works in astronomy and cosmology have relied upon theoretical He I emissivities, but we know of no effort to quantify the uncertainties in the atomic data. We analyze and assign uncertainties to all relevant atomic data, perform Monte Carlo analyses, and report standard deviations in the line emissivities. We consider two sets of errors, which we call "optimistic" and "pessimistic." We also consider three different conditions, corresponding to prototypical Galactic and extragalactic H II regions and the epoch of cosmological recombination. In the extragalactic H II case, the errors we obtain are comparable to or larger than the errors in some recent YpY_p calculations, including those derived from CMB observations. We demonstrate a systematic effect on primordial abundance calculations; this effect cannot be reduced by observing a large number of objects. In the cosmological recombination case, the errors are comparable to many of the effects considered in recent calculations.Comment: 5 pages, 3 figures, accepted to MNRAS Letter
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