Capacity analysis of suburban rail networks

As is well known, capacity evaluation and the identification of bottlenecks on rail networks are complex issues depending upon several technical elements. This is even more perceptible in metropolitan areas where different services (freight, long distance, metro/regional, etc.) are operated using the same limited infrastructures; as a consequence, these facilities may represent bottlenecks of the rail system since they are often highly utilized and congested. This paper tries to explore the issue of capacity evaluation of complex rail networks, proposing synthetic indicators and analyses for feasibility studies or strategic planning. The presented methodology suggests taking into account the main differences in infrastructure characteristics (e.g. single or double lines, signalling systems, terminus or passing stations, etc.) and rail services (e.g. diverse rolling stock, various frequencies, average distances and number of stops, etc.) in order to propose a general approach applicable for capacity analysis of a network as a whole, hence evaluating the utilization rate and the congestion on both lines and stations. To better explore and validate the methodology, an application to a line of the Naples’ suburban network is presented. The results confirm the applicability and effectiveness of the proposed approach; the outcomes indicate the capacity utilization rate of the considered facilities, pointing out likely bottlenecks and possible actions to improve the system efficiency

Environment of the submillimeter-bright massive starburst HFLS3 at z∼z\sim6.34

We describe the search for Lyman-break galaxies (LBGs) near the sub-millimeter bright starburst galaxy HFLS3 at $z$$=$6.34 and a study on the environment of this massive galaxy during the end of reionization.We performed two independent selections of LBGs on images obtained with the \textit{Gran Telescopio Canarias} (GTC) and the \textit{Hubble Space Telescope} (HST) by combining non-detections in bands blueward of the Lyman-break and color selection. A total of 10 objects fulfilling the LBG selection criteria at $z$$>$5.5 were selected over the 4.54 and 55.5 arcmin$^2$ covered by our HST and GTC images, respectively. The photometric redshift, UV luminosity, and the star-formation rate of these sources were estimated with models of their spectral energy distribution. These $z$$\sim$6 candidates have physical properties and number densities in agreement with previous results. The UV luminosity function at $z$$\sim$6 and a Voronoi tessellation analysis of this field shows no strong evidence for an overdensity of relatively bright objects (m$_{F105W}$$<$25.9) associated with \textit{HFLS3}. However, the over-density parameter deduced from this field and the surface density of objects can not excluded definitively the LBG over-density hypothesis. Moreover we identified three faint objects at less than three arcseconds from \textit{HFLS3} with color consistent with those expected for $z$$\sim$6 galaxies. Deeper data are needed to confirm their redshifts and to study their association with \textit{HFLS3} and the galaxy merger that may be responsible for the massive starburst.Comment: 14 pages, 12 figures, accepted for publication in Ap

Guidance on the environmental risk assessment of plant pests

The European Food Safety Authority (EFSA) requested the Panel on Plant Health to develop a methodology for assessing the environmental risks posed by harmful organisms that may enter, establish and spread in the European Union. To do so, the Panel first reviewed the methods for assessing the environmental risks of plant pests that have previously been used in pest risk assessment. The limitations identified by the review led the Panel to define the new methodology for environmental risk assessment which is described in this guidance document. The guidance is primarily addressed to the EFSA PLH Panel and has been conceived as an enhancement of the relevant parts of the “Guidance on a harmonised framework for pest risk assessment and the identification and evaluation of pest risk management options by EFSA”. Emphasizing the importance of assessing the consequences on both the structural (biodiversity) and the functional (ecosystem services) aspects of the environment, this new approach includes methods for assessing both aspects for the first time in a pest risk assessment scheme. A list of questions has been developed for the assessor to evaluate the consequences for structural biodiversity and for ecosystem services in the current area of invasion and in the risk assessment area. To ensure the consistency and transparency of the assessment, a rating system has also been developed based on a probabilistic approach with an evaluation of the degree of uncertainty. Finally, an overview of the available risk reduction options for pests in natural environments is presented, minimum data requirements are described, and a glossary to support the common understanding of the principles of this opinion is provided

Scientific Opinion on the phytosanitary risk associated with some coniferous species and genera for the spread of pine wood nematode

The European Commission requested the Panel on Plant Health to deliver a scientific opinion on the phytosanitary risk of plants (other than fruits and seeds) of Pinus pinea and of the genera Chamaecyparis, Cryptomeria and Juniperus for the spread of pine wood nematode (PWN) via movement of infested plants or untreated plant products or by supporting natural spread of PWN in conjunction with European species of the vector. The Panel analysed the data submitted by Portugal regarding surveys on the Tróia Peninsula where P. pinaster and P. pinea co-occur, and the related laboratory results of Naves et al. (2006) on feeding and oviposition preferences of Monochamus galloprovincialis. The Panel also undertook a comprehensive review of the literature. The zero infestation of PWN recorded on P. pinea on the Tróia Peninsula was not significantly different from the result for P. pinaster, because of the small P. pinea sample. Hence, the conclusion that P. pinea is not a host plant for PWN is not supported by the data submitted, principally because of low statistical confidence arising from the few P. pinea trees present. Moreover, the limited presence of P. pinea in the study areas means that the results are representative neither of the Tróia Peninsula nor of other parts of Portugal. Naves et al. (2006) recorded some oviposition by M. galloprovincialis on P. pinea, but less than on other hosts. No differences in feeding of M. galloprovincialis on P. pinaster and P. pinea were detected, thus potentially allowing PWN transmission to trees by this route. The available information regarding the genera Chamaecyparis, Cryptomeria and Juniperus as potential hosts of Monochamus spp. and PWN suggests overall a low susceptibility to PWN or its vectors; the uncertainty concerning PWN is high and would require supplementary research

Scientific Opinion on the evaluation of the pest risk analysis on Pomacea insularum, the island apple snail, prepared by the Spanish Ministry of Environment and Rural and Marine Affairs

The Panel considers the Spanish pest risk analysis (PRA) to be clear and to provide appropriate supporting evidence. However, (i) the environmental impact assessment is incomplete and (ii) the estimates for the potentially endangered area are too limited. The Panel points out that large areas of the European Union have climatic conditions, that are very similar to those of the areas of native distribution of Pomacea spp. snails, and suitable host plants are available. The Panel agrees with the Spanish PRA on the following points with regard to the risk assessment area: (i) the potential consequences of the organism for rice crops are major; (ii) the probability for establishment of the organism is very likely and (iii) the probability of spread is estimated as likely. The Panel disagrees with the Spanish PRA on the following points and considers (i) the effects on the environment to be massive under suitable environmental conditions in the PRA area and (ii) the probability of entry of the organism to be high. Regarding risk reduction options the Panel agrees with the Spanish PRA that no single risk reduction method is sufficient to halt the introduction and spread of Pomacea spp. snails in the PRA area. However, a legislative ban on import of Pomacea spp. is the only risk reduction option identified that can reduce the probability of entry. The many other risk reduction options listed will help to reduce the probability of spread within the PRA area. The Panel considers that the risk reduction options should target the canaliculata complex, as Pomacea insularum and P. canaliculata, as well as other species from the complex, are almost indistinguishable. This is of particular importance for risk reduction options addressing both breeding and trade of the organism

Statement on a heat treatment to control Agrilus planipennis

In 2011, the EFSA Panel on Plant Health was asked by the European Commission to provide an opinion on a technical file submitted by the US Authorities to support a request to list a new heat treatment (60 °C/60 min) among the EU import requirements for wood of Agrilus planipennis host plants. After a thorough analysis of the documents provided the Panel concluded that, with a low uncertainty, A. planipennis is likely to survive the proposed heat treatment of 60 °C/60 min, and that, to ensure a control level of 99 % the temperature of the heat treatment of 60 min should be higher than 70 °C. Following the publication of this scientific opinion, the US Authorities submitted a new proposal to the European Commission, consisting in a new heat treatment (71.1 °C/60 min). The EFSA Panel on Plant Health was asked to consider whether this new proposal was within the scope of the published opinion and, if not, to clarify its conclusion and indicate what data would be needed to assess the effectiveness of the new treatment. The Panel concluded that the new proposal is not within the scope of the opinion as the data provided by the US Authorities cannot be used to evaluate the effectiveness of the new proposed heat treatment. An accurate assessment of the new proposed heat treatment (71.1 °C/60 min) would require an experiment including several temperatures higher than 70 °C (one corresponding to the proposed treatment). Regarding the data requirements for assessing the effectiveness of the new treatment, the Panel lists the information required in the checklist presented in the Panel’s draft guidance document on methodology for evaluation of the effectiveness of options to reduce the risk of introduction and spread of organisms harmful to plant health in the EU territory, currently under public consultation on EFSA website

Chromosome landmarks and autosome-sex chromosome translocations in Rumex hastatulus, a plant with XX/XY1Y2 sex chromosome system

Rumex hastatulus is the North American endemic dioecious plant with heteromorphic sex chromosomes. It is differentiated into two chromosomal races: Texas (T) race characterised by a simple XX/XY sex chromosome system and North Carolina (NC) race with a polymorphic XX/XY1Y2 sex chromosome system. The gross karyotype morphology in NC race resembles the derived type, but chromosomal changes that occurred during its evolution are poorly understood. Our C-banding/DAPI and fluorescence in situ hybridization (FISH) experiments demonstrated that Y chromosomes of both races are enriched in DAPI-positive sequences and that the emergence of polymorphic sex chromosome system was accompanied by the break of ancestral Y chromosome and switch in the localization of 5S rDNA, from autosomes to sex chromosomes (X and Y2). Two contrasting domains were detected within North Carolina Y chromosomes: the older, highly heterochromatinised, inherited from the original Y chromosome and the younger, euchromatic, representing translocated autosomal material. The flow-cytometric DNA estimation showed ∼3.5 % genome downsizing in the North Carolina race. Our results are in contradiction to earlier reports on the lack of heterochromatin within Y chromosomes of this species and enable unambiguous identification of autosomes involved in the autosome-heterosome translocation, providing useful chromosome landmarks for further studies on the karyotype and sex chromosome differentiation in this species

Scientific opinion on the pest categorization of the tospovirus

The European Commission requested EFSA’s Panel on Plant Health to perform the pest categorisation for the 24 viruses of the Tospovirus genus for the EU territory. The following tospoviruses were analysed: Tomato spotted wilt virus (TSWV), Impatiens necrotic spot virus (INSV), Iris yellow spot virus (IYSV), Polygonum ringspot virus (PolRSV), Groundnut ringspot virus (GRSV), Tomato chlorotic spot virus (TCSV), Alstroemeria necrotic streak virus (ANSV), Chrysanthemum stem necrosis virus (CSNV), Melon severe mosaic virus (MSMV), Tomato yellow (fruit) ring virus (TYRV), Tomato zonate spot virus (TZSV), Groundnut yellow spot virus (GYSV), Groundnut chlorotic fan-spot virus (GCFSV), Groundnut bud necrosis virus (GBNV), Zucchini lethal chlorosis virus (ZLCV), Capsicum chlorosis virus (CaCV), Watermelon bud necrosis virus (WBNV), Watermelon silver mottle virus (WSMoV), Tomato necrotic ringspot virus (TNRV), Calla lily chlorotic spot virus (CCSV), Melon yellow spot virus (MYSV), Soybean vein necrosis associated virus (SVNaV), Bean necrotic mosaic virus (BeNMV) and Pepper necrotic spot virus (PNSV). In reaching its conclusions, the Panel considered four parameters to be of critical importance in the risk assessment area: (i) the presence of a tospovirus, (ii) the existence of host plants, (iii) the existence of thrips vector species and (iv) the potential for damage to crops grown in Europe. Based on its analysis, the Panel concluded that the 24 viruses analysed could be allocated to four different risk groups. Seven viruses (GRSV, TCSV, ANSV, CSNV, MSMV, TYRV, TZSV) for which both thrips species vectors and natural or experimental hosts crops are present in the EU territory were considered by the Panel to represent the highest risk to the EU territory. In contrast, three viruses (INSV, IYSV and PolRSV) already present in the risk assessment area were not considered by the Panel to pose a risk justifying the development of full risk assessments

Statement on the identity of apple snails

Following a request by the European Commission, EFSA‟s Panel on Plant Health was asked to deliver a statement to clarify the current scientific knowledge regarding the identity of the apple snails in the context of the evaluation of the pest risk analysis prepared by the Spanish Ministry of Environment and Rural and Marine Affairs (EFSA Panel on Plant Health (PLH), 2012). The Panel concludes on the risk to plant health posed by Pomacea species in the „canaliculata complex‟, that out of the around 50 species in the genus of Pomacea, four species P. canaliculata, P. insularum, P. lineata and P. maculata belong to the „canaliculata complex‟, where P. insularum and P. maculata are recently considered to be synonyms. Current methods of identification imply high uncertainty if risk reduction options are applied at the Pomacea single species level. The Spanish pest risk analysis identifies important plant health risks connected to Pomacea species. The available scientific evidence indicates that other Pomacea species may pose similar risks to plant health as identified for P. insularum. The Panel clarifies that risk reduction options should not be targeted to single species of the genus Pomacea considering: (i) the dynamical situation in the current study on the systematics of the Ampullariidae species and the genus Pomacea in particular; (ii) the uncertainties and the possible unexpected evolution of the invasive potential of species of Pomacea other than P. insularum and P. canaliculata; (iii) the poor knowledge on the trophic habits of many species of the genus Pomacea, with possible overlaps in the trophic niche (macrophytes); (iv) the high uncertainty on the identification of the different Pomacea species

Pest risk assessment of Monilinia fruticola for the EU territory and identification and evaluation of risk management options

The EFSA Panel on Plant Health has delivered a pest risk assessment on the risk posed by Monilinia fructicola to the EU territory and has identified risk management options and evaluated their effectiveness in reducing the risk to plant health posed by this organism. The Panel has also analysed the effectiveness of the special requirements presently listed in Annex IV, Part A, Section I of Council Directive 2000/29/EC, in reducing the risk of introduction of this pest into the EU territory. The Panel concluded that the main pathways for entry into the EU territory are plant material for propagation purposes and fruit of host genera and that, with the exception of dried fruit, the probability of entry is very likely. The probability of establishment is also very likely due to the suitable environmental conditions and to the widespread presence of host species, susceptible for most of the year, on most of the risk assessment area. Cultural practices and control measures currently applied and competition with other Monilinia species cannot prevent the establishment of M. fructicola. The probability of spread is very likely because of the multiple ways of dispersal of the pest. The overall impact in the endangered area is estimated to be moderate. Neither additional cultural measures nor increased fungicide treatments would be needed to control of brown rot in the orchard after the introduction of M. fructicola