1,557 research outputs found
When a stone tries to climb up a slope:The interplay between lexical and perceptual animacy in referential choices
Several studies suggest that referential choices are influenced by animacy. On the one hand, animate referents are more likely to be mentioned as subjects than inanimate referents. On the other hand, animate referents are more frequently pronominalized than inanimate referents. These effects have been analyzed as effects of conceptual accessibility. In this paper, we raise the question whether these effects are driven only by lexical concepts, such that referents described by animate lexical items (e.g., “toddler”) are more accessible than referents described by inanimate lexical items (e.g., “shoe”), or can also be influenced by context-derived conceptualizations, such that referents that are perceived as animate in a particular context are more accessible than referents that are not. In two animation-retelling experiments, conducted in Dutch, we investigated the influence of lexical and perceptual animacy on the choice of referent and the choice of referring expression. If the effects of animacy are context-dependent, entities that are perceived as animate should yield more subject references and more pronouns than entities that are perceived as inanimate, irrespective of their lexical animacy. If the effects are tied to lexical concepts, entities described with animate lexical items should be mentioned as the subject and pronominalized more frequently than entities described with inanimate lexical items, irrespective of their perceptual animacy. The results show that while only lexical animacy appears to affect the choice of subject referent, perceptual animacy may overrule lexical animacy in the choice of referring expression. These findings suggest that referential choices can be influenced by conceptualizations based on the perceptual context
Reproductive value, sensitivity, and nonlinearity: Population-management heuristics derived from classical demography
In classical demographic theory, reproductive value and stable age distribution are proportional to the sensitivities of the asymptotic population size to changes in mortality and maternity, respectively. In this note we point out that analogous relationships hold if the maternity function is allowed to depend on the population density. The relevant formulae can essentially be obtained by replacing the growth rate ("Lotka'sr") with zero. These facts may be used to derive heuristics for population management (pest control)
Ethyl 6-methyl-4-[2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophen-3-yl]-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate
A new Biginelli compound, C18H25BN2O4S2, containing a boronate ester group was synthesized from a lithium bromide-catalysed reaction. The compound crystallizes with two independent molecules in the asymmetric unit that differ mainly in the conformation of the ester functionality. The crystal structure is stabilized by intermolecular N—H⋯O and N—H⋯S hydrogen bonds involving the 3,4-dihydropyrimidine-2(1H)-thione NH groups as donors and the carbonyl O and thiophene S atoms as acceptors
Dispersion strengthening in vanadium microalloyed steels processed by simulated thin slab casting and direct charging. Part 2 - chemical characterisation of dispersion strengthening precipitates
The composition of the sub-15 nm particles in six related vanadium high strength low alloy steels, made by simulated thin slab direct charged casting, has been determined using electron energy loss spectroscopy (EELS). Such particles are considered to be responsible for dispersion hardening. For the first time, particles down to 4 nm in size have had their composition fully determined. In all the steels, the particles were nitrogen and vanadium rich and possibly slightly sub-stoichiometric carbonitrides. Equilibrium thermodynamics predicted much higher carbon to metal atomic ratios than observed in all cases so that kinetics and mechanical deformation clearly control the precipitation process. Thus it is important to formulate the steel with this in mind
Stimulated Raman adiabatic passage from an atomic to a molecular Bose-Einstein condensate
The process of stimulated Raman adiabatic passage (STIRAP) provides a
possible route for the generation of a coherent molecular Bose-Einstein
condensate (BEC) from an atomic BEC. We analyze this process in a
three-dimensional mean-field theory, including atom-atom interactions and
non-resonant intermediate levels. We find that the process is feasible, but at
larger Rabi frequencies than anticipated from a crude single-mode lossless
analysis, due to two-photon dephasing caused by the atomic interactions. We
then identify optimal strategies in STIRAP allowing one to maintain high
conversion efficiencies with smaller Rabi frequencies and under experimentally
less demanding conditions.Comment: Final published versio
The Internet and the Pandemic
Results from a new Pew Research Center survey of U.S. adults conducted April 12-18, 2021, reveal the extent to which people's use of the internet has changed, their views about how helpful technology has been for them and the struggles some have faced.
Observation of shock waves in a large Bose-Einstein condensate
We observe the formation of shock waves in a Bose-Einstein condensate
containing a large number of sodium atoms. The shock wave is initiated with a
repulsive, blue-detuned light barrier, intersecting the BEC, after which two
shock fronts appear. We observe breaking of these waves when the size of these
waves approaches the healing length of the condensate. At this time, the wave
front splits into two parts and clear fringes appear. The experiment is modeled
using an effective 1D Gross-Pitaevskii-like equation and gives excellent
quantitative agreement with the experiment, even though matter waves with
wavelengths two orders of magnitude smaller than the healing length are
present. In these experiments, no significant heating or particle loss is
observed.Comment: 7 pages, 7 figure
Generation of macroscopic pair-correlated atomic beams by four-wave mixing in Bose-Einstein condensates
By colliding two Bose-Einstein condensates we have observed strong bosonic
stimulation of the elastic scattering process. When a weak input beam was
applied as a seed, it was amplified by a factor of 20. This large gain atomic
four-wave mixing resulted in the generation of two macroscopically occupied
pair-correlated atomic beams.Comment: Please take eps files for best details in figure
Treatment of malignant gliomas with a replicating adenoviral vector expressing herpes simplex virus-thymidine kinase
We evaluated the interaction between oncolytic, replication-competent
adenoviral vectors and the herpes simplex virus-1 thymidine kinase
(HSV1-tk) gene/ganciclovir (GCV) suicide system for the treatment of
malignant gliomas. We constructed a panel of replication-competent
adenoviral vectors in which the luciferase (IG.Ad5E1(+). E3Luc) or HSV1-tk
gene (IG.Ad5E1(+).E3TK) replace the M(r) 19,000 glycoprotein (gp19K)
coding sequence in the E3 region. IG.Ad5E1. IG.Ad5.ClipLuc and IG.AdApt.TK
are E1-deleted viruses that contain the luciferase or the HSV1-tk gene in
the former E1 region driven by the human cytomegalovirus promoter.
IG.Ad5.Sarcoma 1800HSA.E3Luc contains an irrelevant gene in the E1 region,
whereas the gp19K coding sequence in the E3 region is replaced by the
luciferase gene as in the replicating virus IG.Ad5E1(+).E3Luc. For in
vitro experiments, we used a panel of human glioma cell lines (U87 MG,
T98G, A172, LW5, and U251), a rat gliosarcoma cell line (9 L), and human
lung (A549) and prostate carcinoma (P3) cell lines. In vitro, GCV
sensitivity (10 microg/ml) was studied in U87 MG cells after infection at
a multiplicity of infection of 1 and 10. A s.c. U87 MG glioma xenograft
model was established in NIH-bg-nu-xid mice. Tumors of 100-150 mm(3) were
treated with a single injection of adenovirus 10(9) IU suspended in 100
microl of PBS, and GCV 100 mg/kg was administered i.p. twice daily for 7
days. The cytopathic effect of all three replication-competent adenoviral
vectors was similar to the cytopathic effect of wild-type adenovirus 5 on
all human cell lines tested, indicating that deletion of the E3 gp19K
sequences did not affect the oncolytic effect of the vectors. In vitro,
luciferase expression was the same for both E1-deleted vectors
(IG.Ad5.ClipLuc and IG.Ad5.Sarcoma 1800HSA.E3Luc), demonstrating the
strength of the internal E3 promoter even in the absence of E1A. However,
in vitro expression levels obtained with replication-competent
IG.Ad5E1(+). E3Luc were 3 log higher (allowing infection with a
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