Comparative growth and survival of diploid and triploid mozambique tilapia (Oreochromis mossambicus) reared in indoor tanks

In the present study, the effect of cold shock on fertilized eggs of Oreochromis mossambicus was during triploid production. Two males (150 ? 224 g) and six gravid females (150 g to 264 g) were collected. The females were injected with ovulin at a dosage rate of 0.5ml kg(-1), the eggs were stripped into a dry bowl, fertilised with milt, divided into two groups (A and B) and incubated. After three minutes, group A was cold shocked at 50C for a period for 5 min, while group B was incubated normally. Tilapia larvae hatchlings were triplicated and stocked at a density of 200 larvae / liter in the aquaria for four weeks. Results showed that triploid fish had a lower hatchability (58%) and survival rate (47%) than diploid fish (of 85 and 70%, respectively), but a higher specific growth rate of 1.097 as compared to diploid at 0.931. While the improved growth rates have great commercial applications. Further research should be conducted to improve the lower hatchability and survivability of triploid tilapia

Robust and Sparse M-Estimation of DOA

A robust and sparse Direction of Arrival (DOA) estimator is derived for array data that follows a Complex Elliptically Symmetric (CES) distribution with zero-mean and finite second-order moments. The derivation allows to choose the loss function and four loss functions are discussed in detail: the Gauss loss which is the Maximum-Likelihood (ML) loss for the circularly symmetric complex Gaussian distribution, the ML-loss for the complex multivariate $t$-distribution (MVT) with $\nu$ degrees of freedom, as well as Huber and Tyler loss functions. For Gauss loss, the method reduces to Sparse Bayesian Learning (SBL). The root mean square DOA error of the derived estimators is discussed for Gaussian, MVT, and $\epsilon$-contaminated data. The robust SBL estimators perform well for all cases and nearly identical with classical SBL for Gaussian noise

VLBI for Gravity Probe B. V. Proper Motion and Parallax of the Guide Star, IM Pegasi

We present the principal astrometric results of the very-long-baseline interferometry (VLBI) program undertaken in support of the Gravity Probe B (GP-B) relativity mission. VLBI observations of the GP-B guide star, the RS CVn binary IM Pegasi (HR 8703), yielded positions at 35 epochs between 1997 and 2005. We discuss the statistical assumptions behind these results and our methods for estimating the systematic errors. We find the proper motion of IM Peg in an extragalactic reference frame closely related to the International Celestial Reference Frame 2 (ICRF2) to be -20.83 +- 0.03 +- 0.09 mas/yr in right ascension and -27.27 +- 0.03 +- 0.09 mas/yr in declination. For each component the first uncertainty is the statistical standard error and the second is the total standard error (SE) including plausible systematic errors. We also obtain a parallax of 10.37 +- 0.07 mas (distance: 96.4 +- 0.7 pc), for which there is no evidence of any significant contribution of systematic error. Our parameter estimates for the ~25-day-period orbital motion of the stellar radio emission have SEs corresponding to ~0.10 mas on the sky in each coordinate. The total SE of our estimate of IM Peg's proper motion is ~30% smaller than the accuracy goal set by the GP-B project before launch: 0.14 mas/yr for each coordinate of IM Peg's proper motion. Our results ensure that the uncertainty in IM Peg's proper motion makes only a very small contribution to the uncertainty of the GP-B relativity tests.Comment: Accepted for publication in the Astrophysical Journal Supplement Serie

Kajian Sebaran Ukuran Butir Sedimen Di Perairan Gresik, Jawa Timur

Tiap tahun pengangkutan sedimen menuju laut dapat mencapai jutaan meter kubik. Hal tersebut dapat mengakibatkan Perubahan muka bumi dan dapat mengganggu aktivitas dari biota perairan. Sedimen yang telah masuk dalam lingkungan perairan akan mengendap dan terdistribusi oleh proses oseanografi. Lokasi Perairan Gresik yang berada pada muara sungai memiliki kesesuaian dengan kajian penelitian. Tujuan dari penelitian ini adalah untuk mengetahui jenis sedimen di Perairan Gresik dan pendistribusiannya. Penelitian ini menggunakan metode purposive sampling. Hasil dari penelitian ini menunjukkan bahwa terdapat dua fraksi sedimen di Perairan Gresik, yaitu sedimen pasir dan pasir berlanau, dimana pola distribusinya menunjukan daerah pesisir didominasi oleh sedimen pasir dan di laut lepas yang berjenis pasir berlanau

A systematic approach to the Planck LFI end-to-end test and its application to the DPC Level 1 pipeline

The Level 1 of the Planck LFI Data Processing Centre (DPC) is devoted to the handling of the scientific and housekeeping telemetry. It is a critical component of the Planck ground segment which has to strictly commit to the project schedule to be ready for the launch and flight operations. In order to guarantee the quality necessary to achieve the objectives of the Planck mission, the design and development of the Level 1 software has followed the ESA Software Engineering Standards. A fundamental step in the software life cycle is the Verification and Validation of the software. The purpose of this work is to show an example of procedures, test development and analysis successfully applied to a key software project of an ESA mission. We present the end-to-end validation tests performed on the Level 1 of the LFI-DPC, by detailing the methods used and the results obtained. Different approaches have been used to test the scientific and housekeeping data processing. Scientific data processing has been tested by injecting signals with known properties directly into the acquisition electronics, in order to generate a test dataset of real telemetry data and reproduce as much as possible nominal conditions. For the HK telemetry processing, validation software have been developed to inject known parameter values into a set of real housekeeping packets and perform a comparison with the corresponding timelines generated by the Level 1. With the proposed validation and verification procedure, where the on-board and ground processing are viewed as a single pipeline, we demonstrated that the scientific and housekeeping processing of the Planck-LFI raw data is correct and meets the project requirements.Comment: 20 pages, 7 figures; this paper is part of the Prelaunch status LFI papers published on JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/jins

Polaris B, an optical companion of Polaris (alpha UMi) system: atmospheric parameters, chemical composition, distance and mass

We present an analysis of high-resolution spectroscopic observations of Polaris B, the optical companion of the Polaris Ab system. The star has a radial velocity V_r of -16.6km/s to -18.9km/s, and a projected rotational velocity vsini=110 km/s. The derived atmospheric parameters are: Teff=6900K; logg=4.3; V_t=2.5km/s. Polaris B has elemental abundances generally similar to those of the Cepheid Polaris A (Usenko et al. 2005a), although carbon, sodium and magnesium are close to the solar values. At a spectral type of F3V Polaris B has a luminosity of 3.868L_sun, an absolute magnitude of +3.30mag, and a distance of 109.5pc. The mass of the star is estimated to be 1.39M_sun, close to a mass of 1.38+/-0.61M_sun for the recently-resolved orbital periods companion Polaris Ab observed by Evans et al. (2007).Comment: 6 pages, 3 figures, 1 tabl

Design and construction of an optical test bed for LISA imaging systems and tilt-to-length coupling

The laser interferometer space antenna (LISA) is a future space-based interferometric gravitational-wave detector consisting of three spacecraft in a triangular configuration. The interferometric measurements of path length changes between satellites will be performed on optical benches in the satellites. Angular misalignments of the interfering beams couple into the length measurement and represent a significant noise source. Imaging systems will be used to reduce this tilt-to-length coupling. We designed and constructed an optical test bed to experimentally investigate tilt-to-length coupling. It consists of two separate structures, a minimal optical bench and a telescope simulator. The minimal optical bench comprises the science interferometer where the local laser is interfered with light from a remote spacecraft. In our experiment, a simulated version of this received beam is generated on the telescope simulator. The telescope simulator provides a tilting beam, a reference interferometer and an additional static beam as a phase reference. The tilting beam can either be a flat-top beam or a Gaussian beam. We avoid tilt-to-length coupling in the reference interferometer by using a small photo diode placed at an image of the beam rotation point. We show that the test bed is operational with an initial measurement of tilt-to-length coupling without imaging systems. Furthermore, we show the design of two different imaging systems whose performance will be investigated in future experiments

Genomic prediction for Nordic Red Cattle using one-step and selection index blending

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