104 research outputs found
Primera cita de cria de la subespècie cinereocapilla del xàtxero groc Motacilla flava a Mallorca
First Italian yellow wagtail Motacilla flava cinereocapilla breading record for the Balearics. A male showing characters of the subspecies cinereocapilla was recorded in May 2008 singing and defending territory in a wheat field in the vicinity of Santa Margalida in Mallorca. One week later the female was observed constructing the nest and three weeks later both parents were seen feeding the young. This is the first breeding record for this subspecies in the Balearics and may be viewed in context with previous records in NE Spain and S France where there is also a small breeding population. Keywords: Italian Yellow wagtail, Motacilla flava cinereocapilla, breeding, Santa Margalida, Mallorca, Balearics
The Making of the Standard Model
This is the edited text of a talk given at CERN on Septembr 16, 2003, as part
of a celebration of the 30th anniversary of the discovery of neutral currents
and the 20th anniversary of the discovery of the W and Z particles.Comment: 21 page
DNA Renaturation at the Water-Phenol Interface
We study DNA adsorption and renaturation in a water-phenol two-phase system,
with or without shaking. In very dilute solutions, single-stranded DNA is
adsorbed at the interface in a salt-dependent manner. At high salt
concentrations the adsorption is irreversible. The adsorption of the
single-stranded DNA is specific to phenol and relies on stacking and hydrogen
bonding. We establish the interfacial nature of a DNA renaturation at a high
salt concentration. In the absence of shaking, this reaction involves an
efficient surface diffusion of the single-stranded DNA chains. In the presence
of a vigorous shaking, the bimolecular rate of the reaction exceeds the
Smoluchowski limit for a three-dimensional diffusion-controlled reaction. DNA
renaturation in these conditions is known as the Phenol Emulsion Reassociation
Technique or PERT. Our results establish the interfacial nature of PERT. A
comparison of this interfacial reaction with other approaches shows that PERT
is the most efficient technique and reveals similarities between PERT and the
renaturation performed by single-stranded nucleic acid binding proteins. Our
results lead to a better understanding of the partitioning of nucleic acids in
two-phase systems, and should help design improved extraction procedures for
damaged nucleic acids. We present arguments in favor of a role of phenol and
water-phenol interface in prebiotic chemistry. The most efficient renaturation
reactions (in the presence of condensing agents or with PERT) occur in
heterogeneous systems. This reveals the limitations of homogeneous approaches
to the biochemistry of nucleic acids. We propose a heterogeneous approach to
overcome the limitations of the homogeneous viewpoint
The Contribution of CALL to Advanced-Level Foreign/Second Language Instruction
This paper evaluates the contribution of instructional technology to advanced-level foreign/second language learning (AL2) over the past thirty years. It is shown that the most salient feature of AL2 practice and associated Computer-Assisted Language Learning (CALL) research are their rarity and restricted nature. Based on an analysis of four leading CALL journals (CALICO, CALL, LL&T, ReCALL), less than 3% of all CALL publications deal with AL2. Moreover, within this body of research, the range of languages involved is very restricted. Three languages, English, German and French, account for nearly 87% of the studies. Likewise, in nearly 81% of the cases, the learning focus is on the written language. Attention to oral-aural skills accounts for only 18% of all AL2 CALL projects. Whatever the targeted language or linguistic focus, the most striking aspect of advanced-level L2 CALL studies is the lack of information given regarding the competency level of students and the linguistic level of the activities undertaken. The determination of these critical parameters is thus of necessity very much a highly interpretive process. Based on the available evidence, it is estimated that half of the learners in these AL2 studies were in fact within the Common European Framework of Reference (CEFR) B1 range, i.e. below what would generally be considered as advanced-level competency. So, too, half of the assigned tasks were deemed to have been below the B2 level, with 40% of these below the B1 level. This study concludes that both quantitatively and qualitatively the contribution of instructional technology to advanced-level L2 acquisition has been very limited
Measurement of D+- and D0 production in deep inelastic scattering using a lifetime tag at HERA
The production of D-+/-- and D-0-mesons has been measured with the ZEUS detector at HERA using an integrated luminosity of 133.6 pb(-1). The measurements cover the kinematic range 5 < Q(2) < 1000 GeV2, 0.02 < y < 0.7, 1.5 < p(T)(D) < 15 GeV and |eta(D)| < 1.6. Combinatorial background to the D-meson signals is reduced by using the ZEUS microvertex detector to reconstruct displaced secondary vertices. Production cross sections are compared with the predictions of next-to-leading-order QCD, which is found to describe the data well. Measurements are extrapolated to the full kinematic phase space in order to obtain the open-charm contribution, F-2(c (c) over bar), to the proton structure function, F-2
Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at TeV
Inclusive transverse momentum spectra of primary charged particles in Pb-Pb
collisions at = 2.76 TeV have been measured by the ALICE
Collaboration at the LHC. The data are presented for central and peripheral
collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross
section. The measured charged particle spectra in and GeV/ are compared to the expectation in pp collisions at the same
, scaled by the number of underlying nucleon-nucleon
collisions. The comparison is expressed in terms of the nuclear modification
factor . The result indicates only weak medium effects ( 0.7) in peripheral collisions. In central collisions,
reaches a minimum of about 0.14 at -7GeV/ and increases
significantly at larger . The measured suppression of high- particles is stronger than that observed at lower collision energies,
indicating that a very dense medium is formed in central Pb-Pb collisions at
the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98
Two-pion Bose-Einstein correlations in central Pb-Pb collisions at = 2.76 TeV
The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb
collisions at TeV at the Large Hadron Collider is
presented. We observe a growing trend with energy now not only for the
longitudinal and the outward but also for the sideward pion source radius. The
pion homogeneity volume and the decoupling time are significantly larger than
those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/388
Practice patterns and 90-day treatment-related morbidity in early-stage cervical cancer
To evaluate the impact of the Laparoscopic Approach to Cervical Cancer (LACC) Trial on patterns of care and surgery-related morbidity in early-stage cervical cancer
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