4,942 research outputs found
Seasonal Herbage Accumulation of Different Dairy Pasture Types in Southern Australia
Perennial ryegrass pastures, which are the mainstay of dairy feeding systems in southern Australia, are characterised by strong spring growth, little summer/autumn growth, and poor persistence. These limitations impose costs to farm businesses through the purchase of additional fodder to fill feed gaps, and regular re-sowing of pastures. The objective of the research reported here was to investigate the potential for alternative pasture types with different seasonal growth characteristics to improve the seasonal distribution of feed supply and overcome some of the limitations associated with perennial ryegrass
Spatio-Temporal Kronecker Compressive Sensing for Traffic Matrix Recovery
A traffic matrix is generally used by several network management tasks in a data center network, such as traffic engineering and anomaly detection. It gives a flow-level view of the network traffic volume. Despite the explicit importance of the traffic matrix, it is significantly difficult to implement a large-scale measurement to build an absolute traffic matrix. Generally, the traffic matrix obtained by the operators is imperfect, i.e., some traffic data may be lost. Hence, we focus on the problems of recovering these missing traffic data in this paper. To recover these missing traffic data, we propose the spatio-temporal Kronecker compressive sensing method, which draws on Kronecker compressive sensing. In our method, we account for the spatial and temporal properties of the traffic matrix to construct a sparsifying basis that can sparsely represent the traffic matrix. Simultaneously, we consider the low-rank property of the traffic matrix and propose a novel recovery model. We finally assess the estimation error of the proposed method by recovering real traffic
An Evolutionary Algorithm to Generate Real Urban Traffic Flows
In this article we present a strategy based on an evolutionary algorithm to calculate the real vehicle ows in cities according to data from sensors placed in the streets. We have worked with a map imported from OpenStreetMap into the SUMO traffic simulator so that the resulting scenarios can be used to perform different optimizations with the confidence of being able to work with a traffic distribution close to reality. We have compared the results of our algorithm to other competitors and achieved results that replicate the real traffic distribution with a precision higher than 90%.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This research has been partially funded by project number 8.06/5.47.4142 in collaboration with the VSB-Technical University of Ostrava and Universidad de Málaga UMA/FEDER FC14-TIC36, programa de fortalecimiento de las capacidades de I+D+i en las universidades 2014-2015, de la Consejería de Economía, Innovación, Ciencia y Empleo, cofinanciado por el fondo europeo de desarrollo regional (FEDER). Also, partially funded by the Spanish MINECO project TIN2014-57341-R (http://moveon.lcc.uma.es). The authors would like to thank the FEDER of European Union for financial support via project Movilidad Inteligente: Wi-Fi, Rutas y Contaminación (maxCT) of the "Programa Operativo FEDER de Andalucía 2014-2020. We also thank all Agency of Public Works of Andalusia Regional Government staff and researchers for their dedication and professionalism. Daniel H. Stolfi is supported by a FPU grant (FPU13/00954) from the Spanish Ministry of Education, Culture and Sports
Milk Production Potential of Different Dairy Pasture Types in Southern Australia
The growth rate of traditional perennial ryegrass-based pastures commonly fails to meet herd feed requirements through winter and summer in non-irrigated dairy systems in southern Australia. Alternative pasture species can improve seasonal feed supply in this region (Tharmaraj & Chapman, 2005). However, the feeding value and milk production of these pastures must at least match perennial ryegrass if they are to be adopted successfully on dairy farms. This paper reports results of a comparison of the milk production potential of pasture types similar to those investigated by Tharmaraj & Chapman (2005) for their agronomic performance
Infected Cell Killing by HIV-1 Protease Promotes NF-κB Dependent HIV-1 Replication
Acute HIV-1 infection of CD4 T cells often results in apoptotic death of infected cells, yet it is unclear what evolutionary advantage this offers to HIV-1. Given the independent observations that acute T cell HIV-1 infection results in (1) NF-κB activation, (2) caspase 8 dependent apoptosis, and that (3) caspase 8 directly activates NF-κB, we questioned whether these three events might be interrelated. We first show that HIV-1 infected T cell apoptosis, NF-κB activation, and caspase 8 cleavage by HIV-1 protease are coincident. Next we show that HIV-1 protease not only cleaves procaspase 8, producing Casp8p41, but also independently stimulates NF-κB activity. Finally, we demonstrate that the HIV protease cleavage of caspase 8 is necessary for optimal NF-κB activation and that the HIV-1 protease specific cleavage fragment Casp8p41 is sufficient to stimulate HIV-1 replication through NF-κB dependent HIV-LTR activation both in vitro as well as in cells from HIV infected donors. Consequently, the molecular events which promote death of HIV-1 infected T cells function dually to promote HIV-1 replication, thereby favoring the propagation and survival of HIV-1
An extended view of the Pisces Overdensity from the SCUSS survey
SCUSS is a u-band photometric survey covering about 4000 square degree of the
South Galactic Cap, reaching depths of up to 23 mag. By extending around 1.5
mag deeper than SDSS single-epoch u data, SCUSS is able to probe much a larger
volume of the outer halo, i.e. with SCUSS data blue horizontal branch (BHB)
stars can trace the outer halo of the Milky Way as far as 100-150 kpc.
Utilizing this advantage we combine SCUSS u band with SDSS DR9 gri photometric
bands to identify BHB stars and explore halo substructures. We confirm the
existence of the Pisces overdensity, which is a structure in the outer halo (at
around 80 kpc) that was discovered using RR Lyrae stars. For the first time we
are able to determine its spatial extent, finding that it appears to be part of
a stream with a clear distance gradient. The stream, which is ~5 degrees wide
and stretches along ~25 degrees, consists of 20-30 BHBs with a total
significance of around 6sigma over the background. Assuming we have detected
the entire stream and that the progenitor has fully disrupted, then the number
of BHBs suggests the original system was similar to smaller classical or a
larger ultra-faint dwarf galaxy. On the other hand, if the progenitor still
exists, it can be hunted for by reconstructing its orbit from the distance
gradient of the stream. This new picture of the Pisces overdensity sheds new
light on the origin of this intriguing system.Comment: 8 pages, 4 figures, accepted by Ap
Development of a near-real-time global in situ daily precipitation dataset for 0000–0000 UTC
In this study, we have developed a global in situ daily precipitation dataset based on quasi-real-time sub-daily observations of precipitation totals for the 0000–0000 UTC (Co-ordinated Universal Time) day everywhere in the world. The sub-daily precipitation data from meteorological stations are obtained via the World Meteorological Organization's (WMO) Global Telecommunication System (GTS) and China Meteorological Administration Net (CMANet) archived by the National Meteorological Information Centre (NMIC) in China and the Integrated Surface Database (ISD) released by the National Centers for Environmental Information (NCEI) in the USA. We have combined these three sources into a global dataset, referred to as NMIC. Accumulated precipitation totals (depending on the country and the WMO region) are transmitted at a variety of times on the GTS. Of these, about 4,500 stations report daily for the 0000–0000 UTC day. Here, we significantly add to this, by developing two-way accumulation algorithms to decompose other reported sub-daily totals to shorter intervals, and then re-cumulate them where possible to the 0000–0000 UTC day. Using these algorithms, we increase by 51.1% of the number of stations during 2009–2016 to around 6,800 day−1. Additionally, date boundary adjustment (sliding between 1 and 6 hours either side of 0000 UTC) raises the data volume to between 7,800 and 8,700 day−1. We compare our NMIC product with the First Guess Daily (FGD) product from the Global Precipitation Climatology Centre (GPCC) and GHCN-Daily from NCEI (National Centers for Environmental Information). Root mean square differences between our NMIC and GPCC FGD products over the 2009–2016 period are around 3.4–3.7 mm·day−1 and the average consistency percentage is about 75.1–76.8%. Greater differences between NMIC and GHCN-daily are found which are probably due to the non-uniform date boundary in GHCN-Daily
The SDSS-IV extended Baryon Oscillation Spectroscopic Survey: selecting emission line galaxies using the Fisher discriminant
We present a new selection technique of producing spectroscopic target
catalogues for massive spectroscopic surveys for cosmology. This work was
conducted in the context of the extended Baryon Oscillation Spectroscopic
Survey (eBOSS), which will use ~200 000 emission line galaxies (ELGs) at
0.6<zspec<1.0 to obtain a precise baryon acoustic oscillation measurement. Our
proposed selection technique is based on optical and near-infrared broad-band
filter photometry. We used a training sample to define a quantity, the Fisher
discriminant (linear combination of colours), which correlates best with the
desired properties of the target: redshift and [OII] flux. The proposed
selections are simply done by applying a cut on magnitudes and this Fisher
discriminant. We used public data and dedicated SDSS spectroscopy to quantify
the redshift distribution and [OII] flux of our ELG target selections. We
demonstrate that two of our selections fulfil the initial eBOSS/ELG redshift
requirements: for a target density of 180 deg^2, ~70% of the selected objects
have 0.6<zspec<1.0 and only ~1% of those galaxies in the range 0.6<zspec<1.0
are expected to have a catastrophic zspec estimate. Additionally, the stacked
spectra and stacked deep images for those two selections show characteristic
features of star-forming galaxies. The proposed approach using the Fisher
discriminant could, however, be used to efficiently select other galaxy
populations, based on multi-band photometry, providing that spectroscopic
information is available. This technique could thus be useful for other future
massive spectroscopic surveys such as PFS, DESI, and 4MOST.Comment: Version published in A&
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