3,993 research outputs found
First observation of Cherenkov rings with a large area CsI-TGEM-based RICH prototype
We have built a RICH detector prototype consisting of a liquid C6F14 radiator
and six triple Thick Gaseous Electron Multipliers (TGEMs), each of them having
an active area of 10x10 cm2. One triple TGEM has been placed behind the liquid
radiator in order to detect the beam particles, whereas the other five have
been positioned around the central one at a distance to collect the Cherenkov
photons. The upstream electrode of each of the TGEM stacks has been coated with
a 0.4 micron thick CsI layer.
In this paper, we will present the results from a series of laboratory tests
with this prototype carried out using UV light, 6 keV photons from 55Fe and
electrons from 90Sr as well as recent results of tests with a beam of charged
pions where for the first time Cherenkov Ring images have been successfully
recorded with TGEM photodetectors. The achieved results prove the feasibility
of building a large area Cherenkov detector consisting of a matrix of TGEMs.Comment: Presented at the International Conference NDIP-11, Lyon,July201
Ecological risk assessment of contaminated sediments in a harbour site
During major dredging operations in the harbour of Genoa, one of the largest in Italy, a monitoring study was carried out on the quality of marine sediment output, with a view to identifying possible pollutants engendering environmental and ecological risk. The concentration range of all the pollutants evaluated fell within acceptable limits. The only pollutant with concentrations approaching ecological risk levels was nickel. Differences in concentrations of pollutants were mapped and related to special- ized areas of harbour activity
Global Value Chains During the Great Trade Collapse: A Bullwhip Effect?
This paper analyzes the performance of global value chains during the trade collapse. To do so, it exploits a unique transaction-level dataset on French firms containing information on cross-border monthly transactions matched with data on worldwide intra-.rm linkages as defined by property rights (multinational business groups, hierarchies of firms). This newly assembled dataset allows us to distinguish firm-level transactions among two alternative organizational modes of global value chains: internalization of activities (intra- group trade/trade among related parties) or establishment of supply contracts (arm's length trade/trade among unrelated parties). After an overall assessment of the role of global value chains during the trade collapse, we document that intra-group trade in intermediates was characterized by a faster drop followed by a faster recovery than arm's length trade. Amplified fluctuations in terms of trade elasticities by value chains have been referred to as the "bullwhip effect" and have been attributed to the adjustment of inventories within supply chains. In this paper we first con.rm the existence of such an effect due to trade in inter- mediates, and we underline the role that different organizational modes can play in driving this adjustment.trade collapse, multinational firms, global value chains, hierarchies of firms, vertical integration
Precise Determination of Minimum Achievable Temperature for Solid-State Optical Refrigeration
We measure the minimum achievable temperature (MAT) as a function of
excitation wavelength in anti-Stokes fluorescence cooling of high purity
Yb3+-doped LiYF4 (Yb:YLF) crystal. Such measurements were obtained by
developing a sensitive noncontact thermometry that is based on a two-band
differential luminescence spectroscopy using balanced photo-detectors. These
measurements are in excellent agreement with the prediction of the laser
cooling model and identify MAT of 110 K at 1020 nm, corresponding to E4-E5
Stark manifold transition in Yb:YLF crystal.Comment: 10 pages, 6 figure
CAD/CAM Diagnostic Esthetic Functional Splint (DEFS) as a removable prototype to evaluate the final prosthetic rehabilitation: a narrative review.
The main objective of this narrative review was to provide an overview of DEFS (Diagnostic Esthetic Functional Splint), namely CAD/CAM manufactured, “snap-retained”, tooth-colored splints available by materials exhibiting a certain degree of elasticity (like polycarbonates or acetal resins) for restoring function, esthetics and occlusion in several clinical situations, before or as an intermediate alternative to undergoing the final treatment. The search strategy included all papers dealing with snap-retained prosthetic systems and was based on a literature review of papers available in electronic databases (Pubmed/Medline, Evidence-Based Dentistry, BMJ Evidence-Based Medicine, Dynamed, Embase, BMJ Clinical Evidence, Web of Science, Scientific reports); eligible papers were researched on Opengreyand a manual search was performed, as well. From the electronic databases emerged 13,199 records, many of which were duplicates. The grey literature and the manual research did not produce any eligible article. After duplicates removal, 7690 records were obtained. Titles, abstracts and keywords were analyzed. The studies concerning the topic of interest were examined by the reviewers and discussed. Although no evidence-based data were found in the literature, according to the authors’ clinical experience, the DEFS (Diagnostic Esthetic Functional Splint) is a very promising solution in multiple clinical situations, due to its diagnostic, therapeutical, functional and esthetic versatility
Vegetarian and vegan weaning of the infant: How common and how evidence-based? a population-based survey and narrative review
Background: Vegetarian and vegan weaning have increasing popularity among parents and families. However, if not correctly managed, they may lead to wrong feeding regimens, causing severe nutritional deficiencies requiring specific nutritional support or even the need for hospitalization. Aim: To assess the prevalence of vegetarian and vegan weaning among Italian families and to provide an up-to-date narrative review of supporting evidence. Materials and methods: We investigated 360 Italian families using a 40-item questionnaire. The narrative review was conducted searching scientific databases for articles reporting on vegetarian and vegan weaning. Results: 8.6% of mothers follow an alternative feeding regimen and 9.2% of infants were weaned according to a vegetarian or vegan diet. The breastfeeding duration was longer in vegetarian/vegan infants (15.8 vs. 9.7 months; p < 0.0001). Almost half of parents (45.2%) claim that their pediatrician was unable to provide sufficient information and adequate indications regarding unconventional weaning and 77.4% of parents reported the pediatrician’s resistance towards alternative weaning methods. Nine studies were suitable for the review process. The vast majority of authors agree on the fact that vegetarian and vegan weaning may cause severe nutritional deficiencies, whose detrimental effects are particularly significant in the early stages of life. Discussion and conclusion: Our results show that alternative weaning methods are followed by a significant number of families; in half of the cases, the family pediatrician was not perceived as an appropriate guide in this delicate process. To date, consistent findings to support both the safety and feasibility of alternative weaning methods are still lacking. Since the risk of nutritional deficiencies in the early stages of life is high, pediatricians have a pivotal role in guiding parents and advising them on the most appropriate and complete diet regimen during childhood. Efforts should be made to enhance nutritional understanding among pediatricians as an unsupervised vegetarian or vegan diet can cause severe nutritional deficiencies with possible detrimental long-term effects
Financial markets and the allocation of capital: the role of productivity
The efficient allocation of credit is a key element for the success of an economy. Traditional measures of allocative efficiency focus on the Q-theory of investment and, in particular, on the elasticity of finance to investment opportunities proxied by firm real value added. This paper introduces a theorybased alternative measure that focuses instead on the elasticity of credit to firm productivity. In doing so, it develops a simple theoretical framework that delivers clear predictions for the elasticity of credit to current and future productivity depending on capital market frictions. When applied to the novel firm-level dataset of the Competitiveness Research Network (CompNet) set up by the EU System of Central Banks, the proposed measure leads to normative statements about the efficiency of credit allocation across the largest Eurozone economies, changing the conclusions that one would reach based on traditional empirical applications of Q-theory
A New GEM-like Imaging Detector with Electrodes Coated with Resistive Layers
We have developed and tested several prototypes of GEM-like detectors with
electrodes coated with resistive layers: CuO or CrO. These detectors can
operate stably at gains close to 10E5 and they are very robust. We discovered
that the cathodes of these detectors could be coated by CsI layers and in such
a way the detectors gain high efficiency for the UV photons. We also
demonstrated that such detectors can operate stably in the cascade mode and
high overall gains (~10E6) are reachable. This opens applications in several
areas, for example in RICH or in noble liquid TPCs. Results from the first
applications of these devices for UV photon detection at room and cryogenic
temperatures are given.Comment: Presented at the IEEE Nuclear Science Symposium, San Diego,
California, October 200
First report of Berkeleyomyces basicola (synonymous: Thielaviopsis basicola) on roots of sweet potato (Ipomoea batatas (L.) Lam) in Argentina
Symptomatic sweet potato cv Arapey INIA samples were collected from a commercial production field in Colonia Molina, Guaymallén department, Mendoza province, Argentina. They showed dark rounded lesions, sometimes coalescing with white granular mycelium. Fungus was obtained from symptomatic sweet potatoes, which represented the generalized infection that affected the crop. They were seeded in PDA with streptomycin sulfate and incubated for seven days at 21°C, alternating white/black (UV400nm) light. Observations with an optical microscope revealed the presence of hyaline, not septated, cylindrical endoconidia with rounded ends. They were 8-16 μm length and 4–6 μm width. Phialides were 43-46 μm length, rounded bases (7-9 μm width) and tapering to the neck´s tip (4-6 μm width). Brown chlamydospores (aleuriospores), 9-13 μm length and 8-12 μm width, in chains of 2-8 spores were observed. For molecular identification, total genomic DNA was extracted. ITS fragment of 565 pb was amplified using ITS5/ITS4 primers and sequenced. The sequence indicated 99% identity with Berkeleyomyces basicola (synonymous: Thielaviopsis basicola). This was deposited in GenBank as (KX580957) (CBS: C430.74, Gen Bank accession number AF275482.1). This is the first report of B. basicola in sweet potato in Argentina, a potential threat to storage root yields.
Highlights:
Sweet potato black root rot, new disease in Argentina.
First report of Berkeleyomyces basicola causing black root rot on sweet potato in Mendoza, Argentina.Symptomatic sweet potato cv Arapey INIA samples were collected from a commercial production field in Colonia Molina, Guaymallén department, Mendoza province, Argentina. They showed dark rounded lesions, sometimes coalescing with white granular mycelium. Fungus was obtained from symptomatic sweet potatoes, which represented the generalized infection that affected the crop. They were seeded in PDA with streptomycin sulfate and incubated for seven days at 21°C, alternating white/black (UV400nm) light. Observations with an optical microscope revealed the presence of hyaline, not septated, cylindrical endoconidia with rounded ends. They were 8-16 μm length and 4–6 μm width. Phialides were 43-46 μm length, rounded bases (7-9 μm width) and tapering to the neck´s tip (4-6 μm width). Brown chlamydospores (aleuriospores), 9-13 μm length and 8-12 μm width, in chains of 2-8 spores were observed. For molecular identification, total genomic DNA was extracted. ITS fragment of 565 pb was amplified using ITS5/ITS4 primers and sequenced. The sequence indicated 99% identity with Berkeleyomyces basicola (synonymous: Thielaviopsis basicola). This was deposited in GenBank as (KX580957) (CBS: C430.74, Gen Bank accession number AF275482.1). This is the first report of B. basicola in sweet potato in Argentina, a potential threat to storage root yields.
Highlights:
Sweet potato black root rot, new disease in Argentina.
First report of Berkeleyomyces basicola causing black root rot on sweet potato in Mendoza, Argentina
- …