The IceCube Neutrino Observatory - Contributions to ICRC 2017 Part VI: IceCube-Gen2, the Next Generation Neutrino Observatory

Papers on research & development towards IceCube-Gen2, the next generation neutrino observatory at South Pole, submitted to the 35th International Cosmic Ray Conference (ICRC 2017, Busan, South Korea) by the IceCube-Gen2 Collaboration

Large-scale climatic phenomena drive fluctuations in macroinvertebrate assemblages in lowland tropical streams, Costa Rica: The importance of ENSO events in determining long-term (15y) patterns

Understanding how environmental variables influence the distribution and density of organisms over relatively long temporal scales is a central question in ecology given increased climatic variability (e.g., precipitation, ENSO events). The primary goal of our study was to evaluate long-term (15y time span) patterns of climate, as well as environmental parameters in two Neotropical streams in lowland Costa Rica, to assess potential effects on aquatic macroinvertebrates. We also examined the relative effects of an 8y whole-stream P-enrichment experiment on macroinvertebrate assemblages against the backdrop of this long-term study. Climate, environmental variables and macroinvertebrate samples were measured monthly for 7y and then quarterly for an additional 8y in each stream. Temporal patterns in climatic and environmental variables showed high variability over time, without clear inter-annual or intra-annual patterns. Macroinvertebrate richness and abundance decreased with increasing discharge and was positively related to the number of days since the last high discharge event. Findings show that fluctuations in stream physicochemistry and macroinvertebrate assemblage structure are ultimately the result of large-scale climatic phenomena, such as ENSO events, while the 8y P-enrichment did not appear to affect macroinvertebrates. Our study demonstrates that Neotropical lowland streams are highly dynamic and not as stable as is commonly presumed, with high intra- and inter-annual variability in environmental parameters that change the structure and composition of freshwater macroinvertebrate assemblages.This study was financed by National Science Foundation (DEB 1122389) to Catherine M. Pringle. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencias del Mar y Limnología (CIMAR

Pulse shape particle identification by a single large hemispherical photomultiplier tube

© 2020 IOP Publishing Ltd and Sissa Medialab In neutrino experiments, hemispherical photomultiplier tubes (PMTs) are often used to cover large surfaces or volumes to maximize the photocathode coverage with a minimum number of channels. Instrumentation is often coarse, and neutrino event reconstruction and particle identification (PID) is usually done through the morphology of PMT hits. In future neutrino experiments, it may be desirable to perform PID from a few hits, or even a single hit, by utilizing pulse shape information. In this report, we study the principle of pulse shape PID using a single 25.4 cm hemispherical PMT in a spherical glass housing for future neutrino telescopes. We use the Fermilab Test Beam Facility (FTBF) MTest beam line to demonstrate that with pulse shape PID, it is possible to statistically separate 2 GeV electrons from 8 GeV pions, where the total charge deposition is ~20 PE in our setup. Such techniques can be applied to future neutrino telescopes focusing on low-energy physics, including the IceCube-Upgrade

Regeneration and colonization abilities of the invasive species Elodea canadensis and Elodea nuttallii under a salt gradient: implications for freshwater invasibility

International audienceSalinity plays an important role in macrophyte distribution. The current increase in salinization of native freshwaters could modify their susceptibility to invasion. In this study, we determined the tolerance to salt of two invasive macrophytes: Elodea canadensis and Elodea nuttallii. We analysed their growth, regeneration and colonization abilities and the influence of their phenological stage in their response to salt in a laboratory experiment. Traits of both Elodea species varied according to the season and the salt concentration: they were more affected by salt in autumn than in spring, demonstrating higher salt tolerance in spring than in autumn. The two species were sensitive to different thresholds of salinity, although they were both strongly reduced at 3 g l-1 of salt in autumn. Consequently, salt marshes and brackish waters (salt concentration inferior to 3 g l-1 of salt) are likely to be invaded by both species, but the effect of salt levels superior to 3 g l-1 on plant invasiveness needs to be investigated

Polycistronic Herpesvirus Amplicon Vectors for Veterinary Vaccine Development

Heterologous virus-vectored vaccines, particularly those based on canarypox virus vectors, have established a firm place in preventive veterinary medicine. However, herpesvirus-based vaccines have paved the way for DIVA vaccines (discrimination of infected against vaccinated animals), which are particularly desirable for highly contagious livestock diseases that are otherwise combatted by culling of infected animals.In this chapter, we describe the design, the preparation, and the testing of a polycistronic herpesvirus amplicon vaccine against rotaviruses with a particular emphasis on generating heterologous virus-like particles for immunization. After the design, the procedure consists of three steps, first, transient expression of the construct in cell cultures, second, expression and antibody response in a mouse model, and third, application of the system to the desired host species. As a whole, the present information will facilitate the design of novel vaccines of veterinary interest from the designing process until pre-licensing

Satellite-Measured Phytoplankton and Environmental Factors in North Patagonian Gulfs

Abstract An extensive series of high-resolution satellite images from the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS, 2000?2006) was used in thecharacterization of the phytoplankton biomass seasonal cycle of the north Patagoniangulfs (NPG). The NPG system is formed by the San Matías, San José, and Nuevogulfs (between 40°47′and 43°00′S and 63°00′ and 65°1.2′W) and is an area ofecological importance and of great significance for marine conservation in thePatagonian Argentinean Shelf. The spatio temporal variability of phytoplanktonbiomass in each of these environments was characterized by chlorophyll a datafrom satellite images (Chla-sat). The observed seasonal variability was explainedby factors influencing the growth of phytoplankton: photosynthetically availableradiation (PAR from the SeaWiFS sensor) and sea surface temperature (SST fromthe Advanced Very High-Resolution Radiometer, AVHRR). In situ temperature,nutrient, and chlorophyll a concentration data from oceanographic cruises carriedout in Nuevo (four cruises: 1982?1983), San José (four cruises: 1984?1985), andSan Matías (four cruises: 1986?1994) gulfs were also used to explain the observedpatterns. Cycles of phytoplankton and SST over the NPG are typical of temperatewaters. However, Chla-sat cycles were different among gulfs. At the same time,Chla-sat cycles over the gulfs were different from that over the adjacent middlecontinental shelf. SMG was characterized by a bimodal cycle, although in wintermean values were higher than the mean concentration for the whole area. SJG wascharacterized by a unimodal cycle with relatively high values of chlorophyll aconcentration in spring-summer. NG showed a bimodal cycle with maximum valuesin autumn and spring and minimum values in winter and summer. Particularities ofeach gulf are discussed in relation to the seasonal hydrographic characteristics ofthe water column (temperature and nutrients) and in the context of the Patagonianshelf ecosystem.Fil: Williams, Gabriela Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Solis, Miriam Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Esteves, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentin