7,270 research outputs found
Financing behavior of R&D investments in the emerging markets : the role of alliance and financial system
This paper examines the financing behaviour of R&D investments in emerging markets. Drawing on institutional theory and using panel data of generalized methods of moment (GMM) estimation for a sample of 302 firms from 20 countries during the period 2003-2015, we find that emerging market firms tend to use internal funds for financing R&D investments. Interesting results emerged when the sample was divided as alliance and non-alliance firms, and bank-based and market-based financial systems. The results show that R&D financing behaves differently for alliance and non-alliance firms. Alliance firms use both internal and external funds for R&D investments, while non-alliance firms do not use external funds. We also document that a countryâs financial system influences the choice of available sources of finance. Firms from countries that follow a bank-based financial system tend to rely on external funds while firms from countries that follow a market-based financial system depend more on internal funds for financing R&D investments. This study is important as it provides new evidence on financing R&D investments in emerging countries taking into account the institutional arguments of financing choices, and so should guide stakeholders about appropriate sources of R&D financing
Constraining Perturbative Early Dark Energy with Current Observations
In this work, we study a class of early dark energy (EDE) models, in which,
unlike in standard DE models, a substantial amount of DE exists in the
matter-dominated era, self-consistently including DE perturbations. Our
analysis shows that, marginalizing over the non DE parameters such as , current CMB observations alone can constrain the scale factor of
transition from early DE to late time DE to and width of
transition to . The equation of state at present is somewhat
weakly constrained to , if we allow km/s/Mpc. Taken
together with other observations, such as supernovae, HST, and SDSS LRGs, the
constraints are tighter-- .
The evolution of the equation of state for EDE models is thus close to
CDM at low redshifts. Incorrectly assuming DE perturbations to be
negligible leads to different constraints on the equation of state parameters,
thus highlighting the necessity of self-consistently including DE perturbations
in the analysis. If we allow the spatial curvature to be a free parameter, then
the constraints are relaxed to with for CMB+other observations. For
perturbed EDE models, the lower limit on () is much lower than that in CDM (), thus
raising the interesting possibility of discriminating EDE from CDM
using future observations such as halo mass functions or the Sunyaev-Zeldovich
power spectrum.Comment: 12 pages, 5 figures, references updated, accepted for publication in
Ap
Identification of avian Mycoplasma species in commercial broilers and layers with respiratory symptoms in Balochistan
Among many avian mycoplasmas, only the Mycoplasmas gallisepticum (MG) and Mycoplasmas synoviae (MS) are responsible for causing respiratory disease in commercial poultry. This study reported for the very first time the serological occurrence of M. gallisepticum and M. synoviae in blood samples (n = 600) from sixty flocks (n = 42 broiler and n = 18 layer flocks) with respiratory symptoms in Quetta, Pishin and Kuchlak districts of Balochistan, Pakistan. Sera were tested for MG and MS antibody responses by serum plate agglutination (SPA) test and by enzyme-linked immunosorbant assay (ELISA) Synbiotics kit. It was found that M. gallisepticum antibodies in broiler flocks detected by SPA and by ELISA tests were 10.47 and 19.76%, whereas M. synoviae were 7.86 and 11.19%, respectively. In layer flocks the MG and MS antibodies detected by SPA and ELISA were 19.44, 31.66 and 8.8, 25%, respectively. The overall antibodies of MG and MS in both broiler and layer flocks tested by SPA and ELISA was found to be 13.16, 23.33 and 8.16, 15.33%, respectively. In broiler and layer flocks the presence of antibodies against both M. gallisepticum and M. synoviae were found in tested flocks with respiratory symptoms. Further studies on prevalence and diagnosis of both the M. gallisepticum and M. synoviae in causing respiratory disease in commercial broilers and layers in Balochistan are required.Key words: Mycoplasma, broilers, serum plate agglutination, enzyme-linked immunosorbent assay
Excitation of the Earth's Chandler wobble by a turbulent oceanic double-gyre
We develop a layer-averaged, multiple-scale spectral ocean model and show how an oceanic double-gyre can communicate with the Earth's Chandler wobble. The overall transfers of energy and angular momentum from the double-gyre to the Chandler wobble are used to calibrate the turbulence parameters of the layer-averaged model. Our model is tested against a multilayer quasi-geostrophic ocean model in turbulent regime, and base states used in parameter identification are obtained from mesoscale eddy resolving numerical simulations. The Chandler wobble excitation function obtained from the model predicts a small role of North Atlantic ocean region on the wobble dynamics as compared to all oceans, in agreement with the existing observations
Effects of artificial feeds on growth and production of fishes in Polyculture
A study on the effects of artificial feeds on growth and production of fishes along with some limnological conditions were conducted in polyculture system. Species of Indian major carp (Cirrhinus mrigala) and exotic fishes (Hypophthalmicthys molitrix and Oreochromis niloticus) were stocked in six ponds under two treatments, each with three replications. Stocking rate in both treatments was 100 fish per decimal at the ratio of silver carp: tilapia: mrigal = 2: 2: 1. Fertilization and artificial feeds were given in Ttreatment 1 (T1) and only fertilization was done in Treatment 2 (T2). Wheat bran, rice bran and soybean meal were given daily as artificial feed in T1 in the ratio of wheat bran: rice bran: soybean meal = 2: 2: 1 (by wt). Urea, T.S.P and cow dung were applied fortnightly at the rate of 60 g deci-1, 90 g deci-1 and 2 kg deci-1 respectively. Water temperature, transparency, pH, dissolved oxygen, free CO2, total alkalinity, PO4-P and NO3-N were determined fortnightly and phytoplankton and zooplankton were studied fortnightly. These limnological conditions were more or less similar in the ponds under two treatments and were within suitable ranges. Calculated gross and net yields of fish were 16.56 and 12.48 ton ha-1 respectively in case of fertilization and artificial feeding application (T1) and 9.99 and 5.91 ton ha-1 respectively in case of only fertilization (T2). Application of artificial feed in T1 significantly increased the growth and production of fish more than two times which indicates that artificial feeding in polyculture is very useful for increasing fish production. DOI: http://dx.doi.org/10.3329/ijarit.v4i2.22637 Int. J. Agril. Res. Innov. & Tech. 4 (2): 11-15, December, 201
Performance evaluation of High Definition video streaming over Mobile Ad Hoc Networks
© 2018 Video Service Providers (VSPs) can collect and analyze an enormous amount of multimedia data from various cloud storage centers using real-time big data systems for supporting various online customers. The infrastructure-less nature of Mobile Ad Hoc Networks (MANETs) makes the video streaming a challenging task for VSPs. High packet-loss probability in MANETs can create a notable distortion in the received video quality. In this paper, High Definition (HD) videos are streamed over MANETs. First, a transmission model is designed followed by a distortion model to estimate network distortions, such as packet-loss rate and end-to-end delay. Based on the proposed models, a video streaming framework is designed to efficiently utilize the available bandwidth in MANETs, minimize the network distortions, and improve Quality of Service (QoS). Later, an Error Concealment (EC) technique is used to conceal the lost/dropped video frames to improve the Quality of Experience (QoE). Experimental results show that our proposed video streaming framework outperforms the state-of-the-art routing protocols designed for MANETs, such as Destination-Sequenced Distance Vector (DSDV) and Optimized Link Sate Routing (OLSR) protocols. In the end, both subjective and objective evaluations are performed to evaluate the perceptual quality of the concealed video data
Terahertz single pixel imaging based on a Nipkow disk
We describe a terahertz single pixel imaging system based on a Nipkow disk. Nipkow disks have been used for fast scanning imaging systems since the first experimental television was invented in 1926. In our work, a Nipkow disk with 24 scanning lines was used to provide an axial resolution of 2 mm/pixel. We also show that by implementing a microscanning technique the axial resolution can be further improved to 0.5 mm/pixel. Imaging of several objects was demonstrated to show that this simple scanning system is promising for fast and/or real time terahertz imaging applications
Reconstructing the potentials for the quintessence and tachyon dark energy, from the holographic principle
We propose an holographic quintessence and tachyon models of dark energy. The
correspondence between the quintessence and tachyon energy densities with the
holographic density, allows the reconstruction of the potentials and the
dynamics for the quintessence and tachyon fields, in flat FRW background. The
proposed infrared cut-off for the holographic energy density works for two
cases of the constant : for we reconstructed the holographic
quintessence model in the region before the crossing for the EoS
parameter. The cosmological dynamics for was also reconstructed for
the holographic quintessence and tachyon models.Comment: 21 pages, 18 figures, 2 table
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