518 research outputs found

    The north-south asymmetry of the ALFALFA HI velocity width function

    Get PDF
    The number density of extragalactic 21-cm radio sources as a function of their spectral line-widths -- the HI width function (HIWF) -- is a sensitive tracer of the dark matter halo mass function (HMF). The Λ\Lambda cold dark matter model predicts that the HMF should be identical everywhere provided it is sampled in sufficiently large volumes, implying that the same should be true of the HIWF. The ALFALFA 21-cm survey measured the HIWF in northern and southern Galactic fields and found a systematically higher number density in the north. At face value, this is in tension with theoretical predictions. We use the Sibelius-DARK N-body simulation and the semi-analytical galaxy formation model GALFORM to create a mock ALFALFA survey. We find that the offset in number density has two origins: the sensitivity of the survey is different in the two fields, which has not been correctly accounted for in previous measurements; and the 1/Veff1/V_{\mathrm{eff}} algorithm used for completeness corrections does not fully account for biases arising from spatial clustering in the galaxy distribution. The latter is primarily driven by a foreground overdensity in the northern field within 30 Mpc30\,\mathrm{Mpc}, but more distant structure also plays a role. We provide updated measurements of the ALFALFA HIWF (and HIMF) correcting for the variations in survey sensitivity. Only when systematic effects such as these are understood and corrected for can cosmological models be tested against the HIWF.Comment: MNRAS accepte

    The Addition of Ulva Reticulata as a Stimulant Into Artificial Feed on the Gonad Condition of the Collector Sea Urchin (Tripneustes Gratilla Linnaeus 1758)

    Get PDF
    Dried Ulva reticulata has been proven as a feeding stimulant for the collector sea urchins (Tripneustes gratilla). The purposes of this study were to determine the optimal dose of dried U. reticulata as a feeding stimulant into artificial feed and its effect on the gonad condition of the collector sea urchins, T. gratilla. Previously, starved sea urchins (ca. 66 mm diameter, n=7) was held in 80-l aquarium volume with flow through seawater system (6.25 l/hour inlet and outlet). Sea urchins were fed with diet containing 0, 10, 20, or 30% of dried U. reticulata (designated control, U-10, U-20, and U-30 respectively) ad libitum for 38 days. Each treatment was given 3 replicates. Survival rate, feed consumption, and gonad conditions (gonad index, biochemical composition of the gonad, gonad histology, and egg diameter) parameters were quantified and compared to sea urchins fed with the mixture of fresh macroalgae (Gracilaria lichenoides and Padina) and seagrass (Enhalus acoroides). The results showed that the addition of dried U. reticulata into artificial feed by 10% from feed weight (U-10) was the optimal dose recommended. Sea urchins treated U - 10 diet resulted in gonad index and egg diameter (5.02 % and 82.66 µm each), were higher than other diet treatments. However, this diet treatment was not able to homogenize the reproductive phase composition of T. gratilla

    Prospects and Constraints for a Recreational Fishery on East Canyon Creek at the 910 Ranch

    Get PDF
    Summit County Lands and Natural Resources has retained students from Utah State University’s Management and Restoration of Aquatic Ecosystems program to evaluate current conditions of East Canyon Creek (ECC) in the 910 Ranch and propose prospects, constraints, and potential actions to establish a recreational trout fishery

    A novel potential field model for perimeter and agent density control in multiagent swarms

    Get PDF
    parameters for the computation of control vectors. This restriction often limits the structures that can evolve, since agents are unable to modify their behaviour based on their structural role. This paper proposes an enhanced model that uses the perimeter status of agents in selecting control parameters. This allows a wider variety of emergent behaviours, many of which result in much improved swarm structures. The model is based upon equivalence classes of agent pairs, defined by their perimeter status. Array-valued parameters are introduced to allow each equivalence class to be given its own parameter values. The model also introduces a new control vector to ‘flatten’ reflex angles between neighbouring agents on the swarm perimeter, often leading to significantly improved swarm structure. Extensive experiments have been conducted that demonstrate how the new model causes a variety of useful behaviours to emerge from random swarm deployments. The results show that several important behaviours, such as shape control, void removal, perimeter packing and expansion, and perimeter rotation, can be produced without the need for explicit inter-agent communication. The approach is applicable to a variety of applications, including reconnaissance, area-coverage, and containment

    Gonad Maturation of Clown Loach (Botia macracanthus) in Pond

    Get PDF
    The objective of this research is to know the gonad maturation of clown loach {Botia macracanthus) reared in pond. Two groups contain 4 female broodstock; I) carried and II) non-carried egg broodstock were reared in two separated hapas which placed in pond. Each hapa was also stocked nine males. The fish were fed pellet (32,33% protein) 10% biomass, daily in three times. After 20 days, the broodstocks were implanted by LHRH-a 100 u.g/kg of body weight. In the group I, diameter of egg in gonad were developed from 1,028 mm at the beginning of implantation to 1,071 and 1,106 mm at day of 15 and 30 after implantation respectively. In the group II, only one female has developed her gonad successfully. The egg was developed to 0,937 and 1,026 mm after 15 and 30 day implantation respectively. Key words : Gonad maturation, clown loach, Botia macracanthus, pond   ABSTRAK Penelitian ini bertujuan untuk mengetahui pematangan gonad induk ikan botia (Botia macracanthus) yang dipelihara di kolam. Dua kelompok induk betina; I) sudah mengandung telur dan II) belum mengandung telur masing-masing sebanyak 4 ekor dipelihara masing-masing dalam 2 hapa. Ke dalam setiap hapa juga ditempatkan induk jantan sebanyak 9 ekor. Induk diberi pakan berupa pelet (protein, 32,33%) sebanyak 10% dari bobot biomasa per hari, 3 kali sehari, dan diberi LHRH-a dengan dosis 100 ng/kg bobot tubuh secara implantasi pada hari ke 20 pemeliharaan. Induk dalam kelompok pertama telurnya berkembang dari rata-rata 1,028 pada saat pemberian LHRH-a menjadi rata-rata 1,071 dan 1,106 mm masing-masing pada hari ke 15 dan 30 setelah pemberian. Pada kelompok kedua hanya satu ekor induk yang berkembang gonadnya setelah diberi LHRH-a. telur induk ikan tersebut berkembang dari 0,937 menjadi 1,026 mm masing pada hari ke 15 dan 30 setelah implantasi. Kata kunci : Pematangan gonad, ikan botia, Botia macracanthus, kola

    IMPROVING THE EFFICIENCY OF LIGHTING LAMPS AND ENERGY-SAVING TECHNOLOGIES

    Get PDF
    In this article, their energy efficiency was determined by comparing lamps. Currently, led lamps are leading. Instead of traditional sources, energy-saving led lighting can be approximately 93% compared to incandescent lamps; compared to halogen lamps, efficiency is 90% and 66% compared to fluorescent lamps. Led lamp keeps brightness even after using more than 50,000 hours. The average lampshade is 1,000 hours (1,500 hours) and the fluorescent clock is approximately 6,000 hours. If you use led bulbs almost every 8 hours, you need to replace them for 16-17 years. Compared with fluore-scent lamps, energy-saving led lamps do not contain toxic substances or harmful gases. In addition, they do not cause ultraviolet radiation, and cause harm to humans for a long time. The absence of ultraviolet radiation leads to another advantage - they do not attract many types of insecticides that are sensitive to ultraviolet radiation

    Long-Term Ozone Variability and Trends from Reanalyses

    Get PDF
    Stratospheric ozone has a profound impact on radiation and chemistry over various spatial and temporal scales. The evolution of stratospheric ozone over the 21st century, however, is not well understood, especially in the lower stratosphere. Highly vertically resolved ozone data from satellite-borne limb sounders have proved to be invaluable for studying ozone in the middle and upper stratosphere but it was not until recently that these measurements were successfully incorporated in atmospheric reanalyses. Validation and comparison studies have demonstrated that the addition of observations from the Microwave Limb Sounder (MLS) on EOS (Earth Observing System) Aura greatly improved the quality of ozone fields in MERRA-2 (Modern-Era Retrospective analysis for Research and Applications, Version 2) making these assimilated data sets more useful for scientific research. In this presentation we demonstrate that multidecadal lower-stratospheric ozone variability and trends can be derived from NASA's MERRA-2 reanalysis ozone. In particular, the reanalysis ozone bias-corrected using a chemistry model simulation as a transfer function agrees very well with recently reprocessed long ozonesonde records. Ozone trends in the lower stratosphere will be discussed in the context of recent findings (Ball et al., 2018) and interpreted in connection with long-term circulation changes in the lower stratosphere. Next, we show that the use of ozone data retrieved from the next generation OMPS (Ozone Mapping Profiler Suite) instruments, including the OMPS Limb Profiler, can successfully extend the reanalyses into the future allowing comprehensive monitoring of global ozone and interpretation of its evolution during the critical period of expected ozone recovery and climate change from increasing concentration of greenhouse gases

    Gepotidacin for the Treatment of Uncomplicated Urogenital Gonorrhea: A Phase 2, Randomized, Dose-Ranging, Single-Oral Dose Evaluation

    Get PDF
    Background: In this phase 2 study, we evaluated the efficacy and safety of oral gepotidacin, a novel triazaacenaphthylene bacterial type II topoisomerase inhibitor, for the treatment of uncomplicated urogenital gonorrhea. Methods: Adult participants with suspected urogenital gonorrhea were enrolled and completed baseline (day 1) and test-of-cure (days 4-8) visits. Pretreatment and posttreatment urogenital swabs were collected for Neisseria gonorrhoeae (NG) culture and susceptibility testing. Pharyngeal and rectal swab specimens were collected if there were known exposures. Participants were stratified by gender and randomized 1:1 to receive a 1500-mg or 3000-mg single oral dose of gepotidacin. Results: The microbiologically evaluable population consisted of 69 participants, with NG isolated from 69 (100%) urogenital, 2 (3%) pharyngeal, and 3 (4%) rectal specimens. Microbiological eradication of NG was achieved by 97%, 95%, and 96% of participants (lower 1-sided exact 95% confidence interval bound, 85.1%, 84.7%, and 89.1%, respectively) for the 1500-mg, 3000-mg, and combined dose groups, respectively. Microbiological cure was achieved in 66/69 (96%) urogenital infections. All 3 failures were NG isolates that demonstrated the highest observed gepotidacin minimum inhibitory concentration of 1 µg/mL and a common gene mutation. At the pharyngeal and rectal sites, 1/2 and 3/3 NG isolates, respectively, demonstrated microbiological cure. There were no treatment-limiting adverse events for either dose. Conclusions: This study demonstrated that single, oral doses of gepotidacin were ≥95% effective for bacterial eradication of NG in adult participants with uncomplicated urogenital gonorrhea

    GT2004-53122 TECHNICAL AND ECONOMICAL FEASIBILITY OF GAS TURBINE INLET COOLING USING EVAPORATIVE FOGGING SYSTEM IN TWO DIFFERENT LOCATIONS IN OMAN

    Get PDF
    ABSTRACT In this paper gas turbine power boost via inlet air evaporative fogging system is evaluated for power plants of 40 MW power output in two different locations in Sultanate of Oman. The cooling effect is quantified using evaporative cooling degree hour (ECDH) approach. The power output boost based on the month with the highest number of evaporative cooling degree hours reaches as high as 20% for both locations.. This is significant in view of the increased air conditioning load during summer months. It is found that the average net present value (NPV) of installing fogging system in Marmul is 4,622,018andinFahudis4,622,018 and in Fahud is 6,182,496. It is also found that the purchase and installation costs are paid back within the first six months of system operation and for later years, annual revenue of over $500,000 is generated
    • …
    corecore