Reproductive Success of Gulls in the Larus Glaucescens-occidentalis Complex on Protection Island, Washington

Glaucous-winged Gulls (Larus glaucescens) and Western Gulls (Larus occidentalis) hybridize extensively where their ranges meet along the coasts of Washington and Oregon, producing a continuum of phenotypic intergrades between the two parental species. Previous work has shown that hybrids can experience greater reproductive success than parental types by combining adaptive behaviors, such as nest site selection, of both parental species, although success of hybrids may be affected by shifts in the ecotone between marine upwelling and non-upwelling environments. I investigated whether there is a correlation between phenotype, reproductive success, and nest site choice for gulls in Protection Island National Wildlife Refuge, Washington. I examined plumage melanism and bare part coloration in the field to determine a hybrid index for each bird sampled; indices for each member of a sample pair were summed to produce a pair index. Nests were monitored until eggs hatched; nest habitat was recorded as sheltered or unsheltered. Sheltered nests contained larger clutches and exhibited better hatching success but choice of nest habitat was not associated with hybrid index. Pair index was correlated with mass of the third egg of the clutch, with more Western Gulllike pairs producing smaller eggs. However, hybrid index was not significantly correlated with clutch size or hatching success. The distance of an index to the mode of the distribution of indices also was not correlated significantly with clutch size or hatching success; that is, the most abundant phenotypes on the colony were not significantly more or less successful than any other phenotypes

NEMO: A Project for a km3^3 Underwater Detector for Astrophysical Neutrinos in the Mediterranean Sea

The status of the project is described: the activity on long term characterization of water optical and oceanographic parameters at the Capo Passero site candidate for the Mediterranean km$^3$ neutrino telescope; the feasibility study; the physics performances and underwater technology for the km$^3$; the activity on NEMO Phase 1, a technological demonstrator that has been deployed at 2000 m depth 25 km offshore Catania; the realization of an underwater infrastructure at 3500 m depth at the candidate site (NEMO Phase 2).Comment: Proceeding of ISCRA 2006, Erice 20-27 June 200

Upper Limit on the Prompt Muon Flux Derived from the LVD Underground Experiment

We present the analysis of the muon events with all muon multiplicities collected during 21804 hours of operation of the first LVD tower. The measured depth-angular distribution of muon intensities has been used to obtain the normalization factor, A, the power index, gamma, of the primary all-nucleon spectrum and the ratio, R_c, of prompt muon flux to that of pi-mesons - the main parameters which determine the spectrum of cosmic ray muons at the sea level. The value of gamma = 2.77 +/- 0.05 (68% C.L.) and R_c < 2.0 x 10^-3 (95% C.L.) have been obtained. The upper limit to the prompt muon flux favours the models of charm production based on QGSM and the dual parton model.Comment: 10 pages, 4 figures, RevTex. To appear in Phys. Rev.

The ANTARES Optical Beacon System

ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular when a muon is produced, provided that the Cherenkov photons are detected with sufficient timing precision. Considerations of the intrinsic time uncertainties stemming from the transit time spread in the photomultiplier tubes and the mechanism of transmission of light in sea water lead to the conclusion that a relative time accuracy of the order of 0.5 ns is desirable. Accordingly, different time calibration systems have been developed for the ANTARES telescope. In this article, a system based on Optical Beacons, a set of external and well-controlled pulsed light sources located throughout the detector, is described. This calibration system takes into account the optical properties of sea water, which is used as the detection volume of the ANTARES telescope. The design, tests, construction and first results of the two types of beacons, LED and laser-based, are presented.Comment: 21 pages, 18 figures, submitted to Nucl. Instr. and Meth. Phys. Res.

Feeding Interactions Between Juvenile and Adult Flightless Cormorants.

We report observations on chick feedings by adult Flightless Cormorants Phalacrocorax harrisi, indicating that, contrary to the literature, the sequence of interaction is similar to that of other Pelecaniformes

Physical and mechanical properties of sustainable hydraulic mortar based on marble slurry with waste glass

This paper aims to propose and characterize a sustainable hydraulic mortar entirely obtained by the reuse of waste materials, with marble slurry coming from quarries in the northwestern Sicily and glass powder coming from a waste collection plant in Marsala (Province of Trapani). The first was used as raw material to produce the mortar binder by a kilning and slaking process, while the second was used as a pozzolanic additive. The chemical and morphological characterization of the marble slurry was done by XRD, FTIR, STA and SEM analyses. Glass powder was analyzed through particle size distribution measurements, XRD and standard pozzolanic tests. Hydraulic mortars constituted by slaked lime from kilned marble slurry and waste glass powder (LGS) were prepared beside commercial Natural Hydraulic Lime (NHL) based mortars (NGS) and air-hardening lime (LSS)-based mortars. Mechanical and absorption properties of the mortars were investigated as a function of the grain size of the glass powder by means of three-point bending and compressive strength tests, capillary uptake, helium pycnometry and simultaneous thermal analysis. The results demonstrated that the formulation LGS exhibits significantly improved mechanical and absorption properties compared to air-hardening mortars (LSS). It confirms the possibility of producing a more sustainable hydraulic mortar exclusively from waste materials for civil engineering

Effect of sodium bicarbonate treatment on the properties of sisal fibers and their geopolymer composites

Eco-friendly and cheap treatments based on the use of mildly alkaline solutions have been recently investigated to modify natural fibers, altering their surface and improving their compatibility mainly with polymer matrices. A challenge for the researchers is nowadays represented by the assessment of this kind of treatments as a viable approach also for geopolymer based composites. In such a context, this study presents a novel and sustainable approach for enhancing sisal fibers for geopolymer composites using a sodium bicarbonate (NaHCO3) treatment. While the treatment offers a greener alternative to conventional methods, its key advantage lies in achieving a balance between fiber properties. Although it slightly reduces raw fiber strength, the NaHCO3 treatment effectively removes impurities, promoting improved crystallinity and, more importantly, significantly enhances fiber surface roughness and homogeneity. This tailored surface modification fosters superior interfacial bonding with the geopolymer matrix, resulting in composites with significantly enhanced flexural toughness (82 %) – a critical property for construction materials – compared to those reinforced with untreated fibers. Flexural strength is also improved by (53 %). This work not only demonstrates the effectiveness of NaHCO3 treatment but also highlights its potential for developing high-performing, eco-friendly construction materials. A comprehensive evaluation, including three-point bending tests to assess toughness, validates this promising approach

Mechanical and thermal properties of insulating sustainable mortars with ampelodesmos mauritanicus and pennisetum setaceum plants as aggregates

The use of natural fibers in cement composites is a widening research field as their application can enhance the mechanical and thermal behavior of cement mortars and limit their carbon footprint. In this paper, two different wild grasses, i.e., Ampelodesmos mauritanicus, also called diss, and Pennisetum setaceum, also known as crimson fountaingrass, are used as a source of natural aggregates for cement mortars. The main purpose is to assess the possibility of using the more invasive crimson fountaingrass in place of diss in cement-based vegetable concrete. The two plant fibers have been characterized by means of scanning electron microscopy (SEM), helium picnometry and thermogravimetric analysis. Moreover, the thermal conductivity of fiber panels has been measured. Mortars samples have been prepared using untreated, boiled and Polyethylene glycol 4000 (PEG) treated fibers. The mechanical characterization has been performed by means of three point bending and compression tests. Thermal conductivity and porosity have been measured to characterize physical modification induced by fibers’ treatments. The results showed better thermal and mechanical properties of diss fiber composites than fountaingrass one and that fiber treatments lead to a reduction of the thermal insulation propertie

Muon `Depth -- Intensity' Relation Measured by LVD Underground Experiment and Cosmic-Ray Muon Spectrum at Sea Level

We present the analysis of the muon events with all muon multiplicities collected during 21804 hours of operation of the first LVD tower. The measured angular distribution of muon intensity has been converted to the `depth -- vertical intensity' relation in the depth range from 3 to 12 km w.e.. The analysis of this relation allowed to derive the power index, $\gamma$, of the primary all-nucleon spectrum: $\gamma=2.78 \pm 0.05$. The `depth -- vertical intensity' relation has been converted to standard rock and the comparison with the data of other experiments has been done. We present also the derived vertical muon spectrum at sea level.Comment: 7 pages, 3 figures, to be published on Phys. Rev.