472 research outputs found
Acquisition of Differential Object Marking in Argentine Spanish
Acquisition of Differential Object Marking in Argentine Spanish
Humanities, Department of Modern and Classical Languages and Literatures
Variation is ubiquitous to language. For example, Spanish marks animate and specific direct objects (DO) with âaâ (as in: Vi a un niño âI saw a boyâ vs. Vi un carro âI saw a carâ), a phenomenon known as Differential Object Marking (DOM). DOM has been shown to be probabilistically constrained by a number of linguistic factors the speech of Spanish-speaking adults. The only study on first language acquisition of DOM to date, however, has concentrated only on contexts considered categorical (i.e., using âaâ where it is ârequiredâ and zero marking where DOM is âprohibitedâ) and its results are commonly used to suggest very early and errorless acquisition of DOM, albeit in categorical contexts. This study investigates how monolingual Spanish-speaking children arrive at adult-like use of DOM including âand specifically- in contexts where it is probabilistically conditioned. All utterances containing transitive verbs were manually extracted from the Remedi longitudinal corpus of a monolingual Argentine child, available in the online Child Language Data Exchange System database. The corpus contains 14 transcripts of naturalistic conversation between a child aged 1;10-2;11 and her father. Data were further coded for a number of predictor variables known to impact DOM use (such as presence of clitic doubling, DO animacy, DO definiteness, DO specificity). Preliminary analyses revealed that DOM use by both the child and caregiver does not follow categorical rules, revealing a number of datapoints not considered in past research. Analysis of all tokens produced by the child indicates that children may not be as adult-like in DOM use at age two as suggested in the previous literature, but that they are acquiring DOM in a piecemeal fashion
A superburst from 4U 1254-690
We report the detection with the BeppoSAX Wide Field Cameras of a superburst
from 4U 1254-690. The superburst is preceded by a normal type-I X-ray burst,
has a decay time that is the longest of all eight superbursts detected so far
and a peak luminosity that is the lowest. Like for the other seven superbursts,
the origin is a well-known type-I X-ray burster with a persistent luminosity
level close to one tenth of the Eddington limit. Based on WFC data of all
persistently bright X-ray bursters, the average rate of superbursts is
0.51+/-0.25 per year per persistently bright X-ray burster. Some systems may
have higher superburst rates. For all superbursters, we present evidence for a
pure helium layer which is burnt in an unstable as well as a stable manner.Comment: Accepted by A&A Letter
Improving sustainability through intelligent cargo and adaptive decision making
In the current society, logistics is faced with the challenge to meet more stringent sustainability goals. Shippers and transport service providers both aim to reduce the carbon footprint of their logistic operations. To do so, optimal use of logistics resources and physical infrastructure should be aimed for. An adaptive decision making process for the selection of a specific transport modality, transport provider and timeslot (aimed at minimisation of the carbon footprint) enables shippers to achieve this. This requires shippers to have access to up-to-date capacity information from transport providers (e.g. current and scheduled loading status of the various transport means and information on carbon footprint) and traffic information (e.g. city logistics and current traffic information). A prerequisite is an adequate infrastructure for collaboration and open exchange of information between the various stakeholders in the logistics value chain to obtain the up-to-date information. This paper gives a view on how such an advanced information infrastructure can be realised, currently being developed within the EU iCargo project. The paper describes a reference logistics value chain, including business benefits for each of the roles in the logistics value chain of aiming for sustainability. A case analysis is presented that reflects a practical situation in which the various roles collaborate and exchange information for realizing sustainability goals, using adaptive decision making for selecting a transport modality, transport provider, and timeslot. A high-level overview is provided of the requirements on and technical implementation of the supporting advanced infrastructure for collaboration and open information exchange.In the current society, logistics is faced with the challenge to meet more stringent sustainability goals. Shippers and transport service providers both aim to reduce the carbon footprint of their logistic operations. To do so, optimal use of logistics resources and physical infrastructure should be aimed for. An adaptive decision making process for the selection of a specific transport modality, transport provider and timeslot (aimed at minimisation of the carbon footprint) enables shippers to achieve this. This requires shippers to have access to up-to-date capacity information from transport providers (e.g. current and scheduled loading status of the various transport means and information on carbon footprint) and traffic information (e.g. city logistics and current traffic information). A prerequisite is an adequate infrastructure for collaboration and open exchange of information between the various stakeholders in the logistics value chain to obtain the up-to-date information. This paper gives a view on how such an advanced information infrastructure can be realised, currently being developed within the EU iCargo project. The paper describes a reference logistics value chain, including business benefits for each of the roles in the logistics value chain of aiming for sustainability. A case analysis is presented that reflects a practical situation in which the various roles collaborate and exchange information for realizing sustainability goals, using adaptive decision making for selecting a transport modality, transport provider, and timeslot. A high-level overview is provided of the requirements on and technical implementation of the supporting advanced infrastructure for collaboration and open information exchange.In the current society, logistics is faced with the challenge to meet more stringent sustainability goals. Shippers and transport service providers both aim to reduce the carbon footprint of their logistic operations. To do so, optimal use of logistics resources and physical infrastructure should be aimed for. An adaptive decision making process for the selection of a specific transport modality, transport provider and timeslot (aimed at minimisation of the carbon footprint) enables shippers to achieve this. This requires shippers to have access to up-to-date capacity information from transport providers (e.g. current and scheduled loading status of the various transport means and information on carbon footprint) and traffic information (e.g. city logistics and current traffic information). A prerequisite is an adequate infrastructure for collaboration and open exchange of information between the various stakeholders in the logistics value chain to obtain the up-to-date information. This paper gives a view on how such an advanced information infrastructure can be realised, currently being developed within the EU iCargo project. The paper describes a reference logistics value chain, including business benefits for each of the roles in the logistics value chain of aiming for sustainability. A case analysis is presented that reflects a practical situation in which the various roles collaborate and exchange information for realizing sustainability goals, using adaptive decision making for selecting a transport modality, transport provider, and timeslot. A high-level overview is provided of the requirements on and technical implementation of the supporting advanced infrastructure for collaboration and open information exchange
New BeppoSAX-WFC results on superbursts
Presently seven superbursters have been identified representing 10% of the
total Galactic X-ray burster population. Four superbursters were discovered
with the Wide Field Cameras (WFCs) on BeppoSAX and three with the All-Sky
Monitor and Proportional Counter Array on RXTE. We discuss the properties of
superbursters as derived from WFC observations. There are two interesting
conclusions. First, the average recurrence time of superbursts among X-ray
bursters that are more luminous than 10% of the Eddington limit is 1.5 yr per
object. Second, superbursters systematically have higher alpha values and
shorter ordinary bursts than most bursters that have not exhibited superbursts,
indicating a higher level of stable thermonuclear helium burning. Theory
predicts hitherto undetected superbursts from the most luminous neutron stars.
We investigate the prospects for finding these in GX~17+2.Comment: Submitted in January 2004 for the Proceedings of the meeting 'X-Ray
Timing 2003: Rossi and Beyond', eds. P. Kaaret, F. K. Lamb, & J. H. Swank
(Melville, NY: American Institute of Physics
GRB060602B = Swift J1749.4-2807: an unusual transiently accreting neutron-star X-ray binary
We present an analysis of the Swift BAT and XRT data of GRB060602B, which is
most likely an accreting neutron star in a binary system and not a gamma-ray
burst. Our analysis shows that the BAT burst spectrum is consistent with a
thermonuclear flash (type-I X-ray burst) from the surface of an accreting
neutron star in a binary system. The X-ray binary nature is further confirmed
by the report of a detection of a faint point source at the position of the XRT
counterpart of the burst in archival XMM-Newton data approximately 6 years
before the burst and in more recent XMM-Newton data obtained at the end of
September 2006 (nearly 4 months after the burst). Since the source is very
likely not a gamma-ray burst, we rename the source Swift J1749.4-2807, based on
the Swift/BAT discovery coordinates. Using the BAT data of the type-I X-ray
burst we determined that the source is at most at a distance of 6.7+-1.3 kpc.
For a transiently accreting X-ray binary its soft X-ray behaviour is atypical:
its 2-10 keV X-ray luminosity (as measured using the Swift/XRT data) decreased
by nearly 3 orders of magnitude in about 1 day, much faster than what is
usually seen for X-ray transients. If the earlier phases of the outburst also
evolved this rapidly, then many similar systems might remain undiscovered
because the X-rays are difficult to detect and the type-I X-ray bursts might be
missed by all sky surveying instruments. This source might be part of a class
of very-fast transient low-mass X-ray binary systems of which there may be a
significant population in our Galaxy.Comment: Accepted for publication in MNRA
A superburst from GX 3+1
I found one long X-ray flare from the X-ray burster GX 3+1 in almost 6 years
of observations with the RXTE All Sky Monitor (ASM). The event had a peak flux
of about 1.1 Crab (1.5-12 keV), lasted between 4.4 and 16.2 hours and exhibited
a fluence of more than about 5x10^{41} erg for a source distance of 5 kpc.
During the exponential-like decay, with an exponential decay time of 1.6 hours,
spectral softening is seen. The total ASM effective exposure time on GX 3+1 is
estimated to be around a year. The flare bears all the characteristics of the
recently discovered so-called superbursts in other X-ray burst sources.Comment: 4 pages, 1 figure, accepted for A&A Letter
Deliverable 2: Report on the production of GIF by turbot, the effects on growth performance of turbot of local GIF production within RAS and the presence of GIF at commercial farm level
One of the working hypotheses of this project is that growth retardation of turbot cultured in recirculating aquaculture systems (RAS) is caused by the accumulation of growth inhibiting factors (GIF) produced by the turbot themselves in the culture water. Our first goal was to demonstrate the production of growth inhibiting factors by turbot following the methodology of Yurl and Perlmutter. A series of successive experiments was performed. Extracts from turbot culture water were tested for GIF presence in early life stage tests using eggs and larvae and small scale growth trials with juveniles. Our second goal was to demonstrate the transfer of GIF between tanks. Four experiments involving the integration of experimental tanks in a farm scale setting were performed. Our third goal was to demonstrate the presence of GIF at commercial farms. Two juvenile growth trials were performed
Phase separation in the crust of accreting neutron stars
Nucleosynthesis, on the surface of accreting neutron stars, produces a range
of chemical elements. We perform molecular dynamics simulations of
crystallization to see how this complex composition forms new neutron star
crust. We find chemical separation, with the liquid ocean phase greatly
enriched in low atomic number elements compared to the solid crust. This phase
separation should change many crust properties such as the thermal conductivity
and shear modulus. The concentration of carbon, if present, is enriched in the
ocean. This may allow unstable thermonuclear burning of the carbon and help
explain the ignition of the very energetic explosions known as superbursts.Comment: 8 pages, 6 figures, minor changes, Physical Review E in pres
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