89 research outputs found
Structure of rhodolith beds from 4 to 55 meters deep along the southern coast of Espírito Santo State, Brazil
Rhodoliths are one of the most extensive benthic communities of the Brazilian continental shelf, but their structure is poorly
known. The richest marine flora of Brazil’s coastal zone is found in Espírito Santo State and its diversity has been partly
associated with the presence of extensive areas of rhodoliths, extending from the intertidal zone to 120 m across the continental
shelf. One species of kelp, Laminaria abyssalis, is endemic to this area and occurs between 45 and 120 m depth. Our objective
was to determine the density and physical dimensions of the superficial rhodoliths between 4 and 55 m depth in the southern
region of Espírito Santo State. The study area was 3 to 45 km offshore. Samples were obtained in 2004 and 2005 by Scuba
diving in three depth zones: 4–18 m, 25–30 m and 50–55 m. Transect lines and video images were used to determine rhodolith
density. The diameter and sphericity of at least 60 individuals from each zone were measured. Rhodolith size increased and
density decreased from the shallow to the deeper zones. Spheroidal was the typical shape throughout the depth zones. Five
rhodolith-forming genera were identified: Lithothamnion, Lithophyllum, Hydrolithon, Neogoniolithon and Sporolithon.
Epibenthic biomass and species richness over the rhodolith bed in the shallow zone was lowest in winter, likely the result of
disturbance caused by typical winter storms. Changes in light and temperature are probably the most important factors in the
changes observed in the rhodolith beds from the deepest zones.Web of Scienc
FastJet user manual
FastJet is a C++ package that provides a broad range of jet finding and
analysis tools. It includes efficient native implementations of all widely used
2-to-1 sequential recombination jet algorithms for pp and e+e- collisions, as
well as access to 3rd party jet algorithms through a plugin mechanism,
including all currently used cone algorithms. FastJet also provides means to
facilitate the manipulation of jet substructure, including some common boosted
heavy-object taggers, as well as tools for estimation of pileup and
underlying-event noise levels, determination of jet areas and subtraction or
suppression of noise in jets.Comment: 69 pages. FastJet 3 is available from http://fastjet.fr
Energy Loss versus Shadowing in the Drell-Yan Reaction on Nuclei
We present a new analysis of the E772 and E866 experiments on the nuclear
dependence of Drell-Yan (DY) lepton pair production resulting from the
bombardment of , Be, C, Ca, Fe, and W targets by 800 GeV/c protons at
Fermilab. We employ a light-cone formulation of the DY reaction in the rest
frame of the nucleus, where the dimuons detected at small values of Bjorken x_2
<< 1 may be considered to originate from the decay of a heavy photon radiated
from an incident quark in a bremsstrahlung process. We infer the energy loss of
the quark by examining the suppression of the nuclear-dependent DY ratios seen
as a function of projectile momentum fraction x_1 and dimuon mass M. Shadowing,
which also leads to nuclear suppression of dimuons, is calculated within the
same approach employing the results of phenomenological fits to deep inelastic
scattering data from HERA. The analysis yields -dE/dz =2.73 +/- 0.37 +/- 0.5
GeV/fm for the rate of quark energy loss per unit path length, a value
consistent with theoretical expectations including the effects of the inelastic
interaction of the incident proton at the surface of the nucleus. This is the
first observation of a nonzero energy loss effect in such experiments.Comment: 43 pages including 17 figure
Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX collaboration
Extensive experimental data from high-energy nucleus-nucleus collisions were
recorded using the PHENIX detector at the Relativistic Heavy Ion Collider
(RHIC). The comprehensive set of measurements from the first three years of
RHIC operation includes charged particle multiplicities, transverse energy,
yield ratios and spectra of identified hadrons in a wide range of transverse
momenta (p_T), elliptic flow, two-particle correlations, non-statistical
fluctuations, and suppression of particle production at high p_T. The results
are examined with an emphasis on implications for the formation of a new state
of dense matter. We find that the state of matter created at RHIC cannot be
described in terms of ordinary color neutral hadrons.Comment: 510 authors, 127 pages text, 56 figures, 1 tables, LaTeX. Submitted
to Nuclear Physics A as a regular article; v3 has minor changes in response
to referee comments. Plain text data tables for the points plotted in figures
for this and previous PHENIX publications are (or will be) publicly available
at http://www.phenix.bnl.gov/papers.htm
Present Status and Future of DCC Analysis
Disoriented Chiral Condensates (DCC) have been predicted to form in high
energy heavy ion collisions where the approximate chiral symmetry of QCD has
been restored. This leads to large imbalances in the production of charged to
neutral pions. Sophisticated analysis methods are being developed to
disentangle DCC events out of the large background of events with
conventionally produced particles. We present a short review of current
analysis methods and future prospects.Comment: 12 pages, 5 figures. Invited talk presented at the 13th International
Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 97),
Tsukuba, Japan, 1-5 Dec 199
Characteristics of contralateral carcinomas in patients with differentiated thyroid cancer larger than 1 cm
Purpose: Traditionally, total thyroidectomy has been advocated for patients with tumors larger than 1 cm. However, according to the ATA and NCCN guidelines (2015, USA), patients with tumors up to 4 cm are now eligible for lobectomy. A rationale for adhering to total thyroidectomy might be the presence of contralateral carcinomas. The purpose of this study was to describe the characteristics of contralateral carcinomas in patients with differentiated thyroid cancer (DTC) larger than 1 cm. Methods: A retrospective study was performed including patients from 17 centers in 5 countries. Adults diagnosed with DTC stage T1b-T3 N0-1a M0 who all underwent a total thyroidectomy were included. The primary endpoint was the presence of a contralateral carcinoma. Results: A total of 1
Using behavior-analytic implicit tests to assess sexual interests among normal and sex-offender populations
The development of implicit tests for measuring biases and behavioral predispositions is a recent development within psychology. While such tests are usually researched within a social-cognitive paradigm, behavioral researchers have also begun to view these tests as potential tests of conditioning histories, including in the sexual domain.
The objective of this paper is to illustrate the utility of a behavioral approach to implicit testing and means by which implicit tests can be built to the standards of behavioral psychologists.
Research findings illustrating the short history of implicit testing within the experimental analysis of behavior are reviewed. Relevant parallel and overlapping research findings from the field of social cognition and on the Implicit Association Test are also outlined.
New preliminary data obtained with both normal and sex offender populations are described in order to illustrate how behavior-analytically conceived implicit tests may have potential as investigative tools for assessing histories of sexual arousal conditioning and derived stimulus associations.
It is concluded that popular implicit tests are likely sensitive to conditioned and derived stimulus associations in the history of the test-taker rather than 'unconscious cognitions', per se
Running on empty:A metabolomics approach to investigating changing energy metabolism during fasted exercise and rest
Understanding the metabolic processes in energy metabolism, particularly during fasted exercise, is a growing area of research. Previous work has focused on measuring metabolites pre and post exercise. This can provide information about the final state of energy metabolism in the participants, but it does not show how these processes vary during the exercise and any subsequent post-exercise period. To address this, the work described here took fasted participants and subjected them to an exercise and rest protocol under laboratory settings, which allowed for breath and blood sampling both pre, during and post exercise. Analysis of the data produced from both the physiological measurements and the untargeted metabolomics measurements showed clear switching between glycolytic and ketolytic metabolism, with the liquid chromatography-mass spectrometry (LC-MS) data showing the separate stages of ketolytic metabolism, notably the transport, release and breakdown of long chain fatty acids. Several signals, putatively identified as short peptides, were observed to change in a pattern similar to that of the ketolytic metabolites. This work highlights the power of untargeted metabolomic methods as an investigative tool for exercise science, both to follow known processes in a more complete way and discover possible novel biomarkers
How To Find Charm in Nuclear Collisions at RHIC and LHC
Measurements of dilepton production from charm decay and Drell-Yan processes
respectively probe the gluon and sea quark distributions in hadronic
collisions. In nucleus-nucleus collisions, these hard scattering processes
constitute a `background' to thermal contributions from the hot matter produced
by the collision. To determine the magnitude and behavior of this background,
we calculate the hard scattering contribution to dilepton production in nuclear
collisions at RHIC and LHC at next to leading order in perturbative QCD.
Invariant mass, rapidity and transverse momentum distributions are presented.
We compare these results to optimistic hydrodynamic estimates of the thermal
dilepton production. We find that charm production from hard scattering is by
far the dominant contribution. Experiments therefore can measure the gluon
distribution in the nuclear target and projectile and, consequently, can
provide new information on gluon shadowing. We then illustrate how experimental
cuts on the rapidity gap between the leptons can aid in reducing the charm
background, thereby enhancing thermal information.Comment: 32 pages, latex, 19 figure
Towards Jetography
As the LHC prepares to start taking data, this review is intended to provide
a QCD theorist's understanding and views on jet finding at hadron colliders,
including recent developments. My hope is that it will serve both as a primer
for the newcomer to jets and as a quick reference for those with some
experience of the subject. It is devoted to the questions of how one defines
jets, how jets relate to partons, and to the emerging subject of how best to
use jets at the LHC.Comment: 95 pages, 28 figures, an extended version of lectures given at the
CTEQ/MCNET school, Debrecen, Hungary, August 2008; v2 includes additional
discussion in several places, as well as other clarifications and additional
references
- …
