On the formation and physical properties of the Intra-Cluster Light in hierarchical galaxy formation models

We study the formation of the Intra-Cluster Light (ICL) using a semi-analytic model of galaxy formation, coupled to merger trees extracted from N-body simulations of groups and clusters. We assume that the ICL forms by (1) stellar stripping of satellite galaxies and (2) relaxation processes that take place during galaxy mergers. The fraction of ICL in groups and clusters predicted by our models ranges between 10 and 40 per cent, with a large halo-to-halo scatter and no halo mass dependence. We note, however, that our predicted ICL fractions depend on the resolution: for a set of simulations with particle mass one order of magnitude larger than that adopted in the high resolution runs used in our study, we find that the predicted ICL fractions are ~30-40 per cent larger than those found in the high resolution runs. On cluster scale, large part of the scatter is due to a range of dynamical histories, while on smaller scale it is driven by individual accretion events and stripping of very massive satellites, $M_{*} \gtrsim 10^{10.5} M_{\odot}$, that we find to be the major contributors to the ICL. The ICL in our models forms very late (below $z\sim 1$), and a fraction varying between 5 and 25 per cent of it has been accreted during the hierarchical growth of haloes. In agreement with recent observational measurements, we find the ICL to be made of stars covering a relatively large range of metallicity, with the bulk of them being sub-solar.Comment: Accepted for Publication in MNRAS, 19 pages, 13 figures, 1 tabl

Integration of monoterpenoids with low pressure simulating vacuum for control of diapausing Indian meal moth larvae and red flour beetle adults

Monoterpenoids as well as low pressure simulating vacuum, when applied alone have been demonstrated to cause mortality of stored-product insect pests. The current report explored the possibility of integrating these two control methods in the management of stored-product insects. The insects used for this study were the adults of the red flour beetle, Tribolium castaneum, and diapausing larvae of the Indian meal moth, Plodia interpunctella. The monoterpenoids investigated were E-anethole, estragole, S-carvone, linalool, L-fenchone, geraniol, γ-terpinene and DL-camphor. Exposure of the insects to all the monoterpenoids alone, with the exception of camphor, at a concentration of 66.7μL/1L of volume required more than 24 h to generate 100% mortality at 28.0 ± 0.8°C and 70 ± 2.5 r.h. However, exposure of the insects to camphor alone generated 100% mortality with 3 h exposure in T. castaneum. Exposure of the insects to low pressure at 36.5 mm Hg generated 100% mortlity in beetles with 24 h exposure and in the diapausing P. interpunctella larvae with 48 h exposure. However, combination of the monoterpenoids with low pressure reduced exposure periods (3-24 h) required to generate 100% mortality in both diapausing larvae of P. interpunctella and the adult beetles of T. castaneum. In all cases T. castaneum showed signs of weakness faster than diapausing P. interpunctella larvae. Keywords: Low pressure, DL-camphor, Estragole, γ-terpinene, Carvon

Strandings of Leatherback turtles (Dermochelys coriacea) along the western and southern coast of the Gulf of Venezuela

Leatherback Turtle (Dermochelys coriacea) strandings in the Gulf of Venezuela (GV) were evaluated to estimate: (1) the area of most frequent strandings; (2) the period of greatest strandings; and (3) the number of strandings that exhibit evidence of human interaction. We gathered data from three sources: (1) scientific patrols; (2) Opportune Information Network (in Spanish Red de Aviso Oportuno – RAO); and (3) contact with local non-governmental organization. At each stranding site, we collected information about the location, date, specimen condition, and, when possible, the midline curved carapace length (CCL) and curved carapace width (CCW). We categorized the cause of strandings as either interaction with human activities or an unknown cause. We recorded 57 Leatherback Turtle strandings along the GV coast during 2001–2007. The mean CCL was 126.2 cm ± 16.5 (range 86–168 cm, n = 47) and the mean CCW was 99.1cm ± 12.6 (range 83–109 cm, n = 47). Strandings were mainly distributed along the North and South coast (49% and 46%, respectively), and were mostly concentrated between February and March (51%). Over half (55%) of the strandings showed signs of interaction with human activities. Establishing a relationship between fisheries and strandings in the GV remains difficult. Although the stranding number reported is low when compared to other localities, our results represent a minimum estimate of mortality. A management plan is crucial for mitigating possible impacts of artisanal fisheries in the region

A Prototype Fast Multiplicity Discriminator for ALICE L0 Trigger

The design details and test results of a prototype Multiplicity Discriminator (MD) for the ALICE L0 Trigger electronics are presented. The MD design is aimed at the earliest trigger decision founded on a fast multiplicity signal cut, in both options for the ALICE centrality detector: Micro Channel Plates or Cherenkov counters. The MD accepts detector signals with an amplitude range of plus-minus 2.5 V, base duration of 1.8 ns and rise time of 300-400 ps. The digitally controlled threshold settings give an accuracy better than 0.4% at the maximum amplitude of the accepted pulses. The MD internal latency of 15 ns allows for a decision every LHC bunch crossing period, even for the 40 MHz of p-p collisions

Contribution of Insect Pollination to Macadamia integrifolia Production in Hawaii

The honeybee, Apis mellifera, is commonly accepted to be an important pollinator in many agricultural crop systems in Hawaii. However, specific details on the importance of A. mellifera, along with other insect visitors have not been determined for macadamia nut orchards in Hawaii. Reductions in feral honeybee populations in Hawaii attributable to invasions by varroa mites (Varroa destruc- tor) and small hive beetle (Aethina tumida) have resulted in growers becoming dependent on managed bees, requiring increased understanding of the role they play as pollinators. Several parameters determining the contributions of insect pollinators in macadamia nuts were measured: (1) species richness and abun- dance of insects visiting macadamia flowers, (2) the effects of insect pollination in regards to fruit set, fruit retention, fruit size, and weight, and (3) insect pollen removal efficacy based on the mean number of pollen grains an individual insect removed from the stigma while foraging on a macadamia flower. The results from data collected in the study orchard showed that while the order Diptera ranked highest in species richness (9 species), A. mellifera was the most abundant species visiting the macadamia inflorescences (62.7% in abundance, with an average of 17 honeybees seen per 15 minutes compared to 8 flies per 15 minutes). Inflores- cences that were accessible to insects for pollination produced higher fruit sets and yield compared to inflorescences from which insect visitation was excluded. Abundance, foraging behavior and stigma contact, suggested that honeybees are the greatest contributors to macadamia nut pollination over other insects observed in the orchard. The hoverflies (Syrphidae) observed in the orchard may have con- tributed to pollination, but likely to a lesser extent than the honeybees due to the low abundance of the flies

The occurrence of epibionts of Gordiida (Nematomorpha) in Catamarca, Argentina

The presence of larvae and pupae of the genus Metrichia (Trichoptera, Hydroptilidae), larvae of the genus Macrelmis and Phanocerus (Coleoptera, Elmidae), three diatom genera Achnanthes, Cocconeis, Gomphonema, and some specimens of very small diatoms that could not be determined to species or genus level, were recorded for the first time as epibionts for Chordodes brasiliensis (Gordiida, Nematomorpha). Such epibionts were found on the body surface of this species of hairworms, captured from El Tala stream, Catamarca, Argentina.Facultad de Ciencias Naturales y Muse

The occurrence of epibionts of Gordiida (Nematomorpha) in Catamarca, Argentina

The presence of larvae and pupae of the genus Metrichia (Trichoptera, Hydroptilidae), larvae of the genus Macrelmis and Phanocerus (Coleoptera, Elmidae), three diatom genera Achnanthes, Cocconeis, Gomphonema, and some specimens of very small diatoms that could not be determined to species or genus level, were recorded for the first time as epibionts for Chordodes brasiliensis (Gordiida, Nematomorpha). Such epibionts were found on the body surface of this species of hairworms, captured from El Tala stream, Catamarca, Argentina.Facultad de Ciencias Naturales y Muse

The ability of four strains of Streptococcus uberis to induce clinical mastitis after intramammary inoculation in lactating cows

AIM: To compare the ability of four strains of Streptococcus uberis at two doses to induce clinical mastitis in lactating dairy cows after intramammary inoculation in order to evaluate their usefulness for future experimental infection models. MATERIALS AND METHODS: Four field strains of Streptococcus uberis (26LB, S418, and S523 and SR115) were obtained from cows with clinical mastitis in the Wairarapa and Waikato regions of New Zealand. Twenty-four crossbred lactating cows, with no history of mastitis and absence of major pathogens following culture of milk samples, were randomly allocated to four groups (one per strain) of six cows. Each cow was infused (Day 0) in one quarter with approximately 104 cfu and in the contralateral quarter with approximately 106 cfu of the same strain. The other two quarters remained unchallenged. All four quarters were then inspected for signs of clinical mastitis, by palpation and observation of the foremilk, twice daily from Days 0–9, and composite milk samples were collected from Days 0–8 for analysis of somatic cell counts (SCC). Quarters were treated with penicillin when clinical mastitis was observed. Duplicate milk samples were collected and cultured on presentation of each clinical case and on Day 4 from challenged quarters with no clinical signs. RESULTS: Clinical mastitis was diagnosed in 26/48 (54%) challenged quarters. Challenge with strain S418 resulted in more cases of mastitis (12/12 quarters) than strains SR115 (7/12), 26LB (6/12) or S523 (1/12), and the mean interval from challenge to first diagnosis of mastitis was shorter for S418 than the other strains (p<0.001). The proportion of quarters from which S. uberis could be isolated after challenge was less for strain 26LB (1/6) than SR115 (6/7) (p<0.05), and SCC following challenge was lower for strain S523 than the other strains (p<0.05). CONCLUSIONS: There were significant differences between the strains in the proportion of quarters developing clinical mastitis, the interval to mastitis onset, SCC following challenge and the proportion of clinical cases from which S. uberis could be isolated. These results illustrate the difference in the ability of S. uberis strains to cause mastitis and the severity of the infections caused. CLINICAL RELEVANCE: Experimental challenge models can be used to compare infectivity and pathogenicity of different strains of mastitis-causing bacteria, the efficacy of pharmaceutical products and host-responses in a cost-effective manner.S Notcovich, G deNicolo, NB Williamson, A Grinberg, N Lopez-Villalobos, KR Petrovsk