1,944 research outputs found
RPCH modulation of a multi-oscillator network: Effects on the pyloric network of the spiny lobster
The neuropeptide red pigment concentrating hormone (RPCH), which we have previously shown to activate the cardiac sac motor pattern and lead to a conjoint gastric mill-cardiac sac pattern in the spiny lobster Panulirus, also activates and modulates the pyloric pattern. Like the activity of gastric mill neurons in RPCH, the pattern of activity in the pyloric neurons is considerably more complex than that seen in control saline. This reflects the influence of the cardiac sac motor pattern, and particularly the upstream inferior ventricular (IV) neurons, on many of the pyloric neurons. RPCH intensifies this interaction by increasing the strength of the synaptic connections between the IV neurons and their targets in the stomatogastric ganglion. At the same time, RPCH enhances postinhibitory rebound in the lateral pyloric (LP) neuron. Taken together, these factors largely explain the complex pyloric pattern recorded in RPCH in Panulirus
Neurotransmitter interactions in the stomatogastric system of the spiny lobster: One peptide alters the response of a central pattern generator to a second peptide
Two of the peptides found in the stomatogastric nervous system of the spiny lobster. Panulirus interruptus, interacted to modulate the activity of the cardiac sac motor pattern. In the isolated stomatogastric ganglion, red- pigment-concentrating hormone (RPCH), but not proctolin, activated the bursting activity in the inferior ventricular (IV) neurons that drives the cardiac sac pattern. The cardiac sac pattern normally ceased within 15 min after the end of RPCH superfusion. However, when proctolin was applied within a few minutes of that time, it was likewise able to induce cardiac sac activity. Similarly, proctolin applied together with subthreshold RPCH induced cardiac sac bursting. The amplitude of the excitatory postsynaptic potentials from the IV neurons to the cardiac sac dilator neuron CD2 (1 of the 2 major motor neurons in the cardiac sac system) was potentiated in the presence of both proctolin and RPCH. The potentiation in RPCH was much greater than in proctolin alone. However, the potentiation in proctolin after RPCH was equivalent to that recorded in RPCH alone. Although we do not yet understand the mechanisms for these interactions of the two modulators, this study provides an example of one factor that can determine the \u27state\u27 of the system that is critical in determining the effect of a modulator that is \u27state dependent,\u27 and it provides evidence for yet another level of flexibility in the motor output of this system
Dual-readout Calorimetry
The RD52 Project at CERN is a pure instrumentation experiment whose goal is
to understand the fundamental limitations to hadronic energy resolution, and
other aspects of energy measurement, in high energy calorimeters. We have found
that dual-readout calorimetry provides heretofore unprecedented information
event-by-event for energy resolution, linearity of response, ease and
robustness of calibration, fidelity of data, and particle identification,
including energy lost to binding energy in nuclear break-up. We believe that
hadronic energy resolutions of {\sigma}/E 1 - 2% are within reach for
dual-readout calorimeters, enabling for the first time comparable measurement
preci- sions on electrons, photons, muons, and quarks (jets). We briefly
describe our current progress and near-term future plans. Complete information
on all aspects of our work is available at the RD52 website
http://highenergy.phys.ttu.edu/dream/.Comment: 10 pages, 10 figures, Snowmass White pape
Hadron detection with a dual-readout fiber calorimeter
In this paper, we describe measurements of the response functions of a
fiber-based dual- readout calorimeter for pions, protons and multiparticle
"jets" with energies in the range from 10 to 180 GeV. The calorimeter uses lead
as absorber material and has a total mass of 1350 kg. It is complemented by
leakage counters made of scintillating plastic, with a total mass of 500 kg.
The effects of these leakage counters on the calorimeter performance are
studied as well. In a separate section, we investigate and compare different
methods to measure the energy resolution of a calorimeter. Using only the
signals provided by the calorimeter, we demonstrate that our dual-readout
calorimeter, calibrated with electrons, is able to reconstruct the energy of
proton and pion beam particles to within a few percent at all energies. The
fractional widths of the signal distributions for these particles (sigma/E)
scale with the beam energy as 30%/sqrt(E), without any additional contributing
terms
Measurement of the Xi-p Scattering Cross Sections at Low Energy
In this paper we report cross-section measurements for elastic and
inelastic scatterings at low energy using a scintillating fiber active target.
Upper limit on the total cross-section for the elastic scattering was found to
be 24 mb at 90% confidence level, and the total cross section for the
reaction was found to be mb. We
compare the results with currently competing theoretical estimates.Comment: 9 page
Zastosowanie leku XENical w zapobieganiu cukrzycy u osób z otyłością — badanie XENDOS. Badanie randomizowane z zastosowaniem orlistatu jako dodatkowego, oprócz zmian stylu życia, czynnika zapobiegania cukrzycy typu 2 u pacjentów z otyłością
INTRODUCTION. It is well established that the risk of
developing type 2 diabetes is closely linked to the
presence and duration of overweight and obesity.
A reduction in the incidence of type 2 diabetes with
lifestyle changes has previously been demonstrated.
We hypothesized that adding a weight-reducing
agent to lifestyle changes may lead to an even greater
decrease in body weight, and thus the incidence
of type 2 diabetes, in obese patients.
MATERIAL AND METHODS. In a 4-year, double-blind,
prospective study, we randomized 3,305 patients to lifestyle
changes plus either orlistat 120 mg or placebo,
three times daily. Participants had a BMI ≥ 30 kg/m2
and normal (79%) or impaired (21%) glucose tolerance
(IGT). Primary endpoints were time to onset
of type 2 diabetes and change in body weight. Analyses
were by intention to treat.
RESULTS. Of orlistat-treated patients, 52% completed
treatment compared with 34% of placebo recipients
(P < 0.0001). After 4 years’ treatment, the
cumulative incidence of diabetes was 9.0% with placebo
and 6.2% with orlistat, corresponding to a risk
reduction of 37.3% (P = 0.0032). Exploratory analyses
indicated that the preventive effect was explained
by the difference in subjects with IGT. Mean
weight loss after 4 years was significantly greater
with orlistat (5.8 vs. 3.0 kg with placebo; P < 0.001)
and similar between orlistat recipients with impaired
(5.7 kg) or normal glucose tolerance (NGT) (5.8 kg) at
baseline. A second analysis in which the baseline weights
of subjects who dropped out of the study was
carried forward also demonstrated greater weight loss
in the orlistat group (3.6 vs. 1.4 kg; P < 0.001).
CONCLUSIONS. Compared with lifestyle changes alone,
orlistat plus lifestyle changes resulted in a greater
reduction in the incidence of type 2 diabetes over
4 years and produced greater weight loss in a clinically
representative obese population. Difference in diabetes
incidence was detectable only in the IGT subgroup;
weight loss was similar in subjects with IGT and or NGT.WSTĘP. Ryzyko rozwoju cukrzycy typu 2 wiąże się ściśle z obecnością i czasem
trwania nadwagi oraz otyłości. Wpływ wprowadzenia zmian stylu życia na zmniejszenie
częstości cukrzycy typu 2 potwierdzono we wcześniejszych badaniach. Wysunięto
hipotezę, według której zastosowanie dodatkowego czynnika powodującego zmniejszenie
masy ciała u chorych, którym udało się ten cel częściowo osiągnąć pod wpływem
zmiany stylu życia, pozwala uzyskać jeszcze lepsze efekty, a w konsekwencji prowadzi
do dalszej redukcji częstości cukrzycy typu 2 u pacjentów z otyłością.
MATERIAŁ I METODY. Do trwającego 4 lata, prospektywnego, randomizowanego
badania, przeprowadzonego metodą podwójnie ślepej próby zakwalifikowano 3305 pacjentów,
których losowo podzielono na dwie grupy. W pierwszej grupie, obok wprowadzenia
zmian stylu życia, pacjentom podawano 3 razy na dobę orlistat w dawce 120 mg,
a w drugiej — placebo. Wskaźnik masy ciała (BMI, body mass index) uczestników
badania był większy lub równy 30 kg/m2, stężenie glukozy było prawidłowe (79%)
lub rozpoznawano upośledzoną tolerancję glukozy (IGT, impaired glucose tolerance)
(21%). Jako główne kryterium oceny badania przyjęto czas do wystąpienia cukrzycy
typu 2 oraz zmianę masy ciała. Przeprowadzono analizę według pierwotnej intencji
leczenia (intention to treat).
WYNIKI. Leczenie ukończyło 52% badanych otrzymujących orlistat i 34% przyjmujących
placebo (p < 0,0001). Po 4 latach terapii skumulowane ryzyko wystąpienia cukrzycy
w grupie otrzymującej placebo wyniosło 9%, natomiast w grupie przyjmującej orlistat
— 6,2%, co oznacza redukcję ryzyka o 37,3% (p = 0,0032). Na podstawie analizy
uzyskanych danych stwierdzono, że efekt prewencyjny wynikał z różnic wśród pacjentów
z upośledzoną tolerancją glukozy. Średnia redukcja masy ciała po 4 latach obserwacji
była znacząco wyższa w grupie leczonej orlistatem (5,8 vs. 3,0 kg w grupie otrzymującej
placebo; p < 0,001) oraz podobna u pacjentów otrzymujących orlistat z wyjściową
upośledzoną (5,7 kg) lub prawidłową tolerancją glukozy (NGT, normal glucose tolerance)
(5,8 kg). W drugiej analizie, w której uwzględniono zmiany masy ciała u osób wyłączonych
z badania, również wykazano większą redukcję masy ciała w grupie leczonej orlistatem
(3,6 vs. 1,4 kg; p < 0,001).
WNIOSKI. W badaniu przeprowadzonym w reprezentatywnej populacji osób z
otyłością wykazano, że w porównaniu z postępowaniem opartym wyłącznie na zmianie
stylu życia, dodanie orlistatu spowodowało większy spadek częstości cukrzycy typu
2 oraz większą redukcję masy ciała w okresie 4 lat. Różnica w częstości cukrzycy
była widoczna tylko w podgrupie z IGT, zmniejszenie masy ciała było podobne zarówno
w podgrupie z IGT, jak i z NGT
Molecular characterization of microbiota in cerebrospinal fluid from patients with CSF shunt infections using whole genome amplification followed by shotgun sequencing
Understanding the etiology of cerebrospinal fluid (CSF) shunt infections and reinfections requires detailed characterization of associated microorganisms. Traditionally, identification of bacteria present in the CSF has relied on culture methods, but recent studies have used high throughput sequencing of 16S rRNA genes. Here we evaluated the method of shotgun DNA sequencing for its potential to provide additional genomic information. CSF samples were collected from 3 patients near the beginning and end of each of 2 infection episodes. Extracted total DNA was sequenced by: (1) whole genome amplification followed by shotgun sequencing (WGA) and (2) high-throughput sequencing of the 16S rRNA V4 region (16S). Taxonomic assignments of sequences from WGA and 16S were compared with one another and with conventional microbiological cultures. While classification of bacteria was consistent among the 3 approaches, WGA provided additional insights into sample microbiological composition, such as showing relative abundances of microbial versus human DNA, identifying samples of questionable quality, and detecting significant viral load in some samples. One sample yielded sufficient non-human reads to allow assembly of a high-qualit
Lambda^0 polarization as a probe for production of deconfined matter in ultra-relativistic heavy-ion collisions
We study the polarization change of Lambda^0's produced in ultra-relativistic
heavy-ion collisions with respect to the polarization observed in proton-proton
collisions as a signal for the formation of a Quark-Gluon Plasma (QGP).
Assuming that, when the density of participants in the collision is larger than
the critical density for QGP formation, the Lambda^0 production mechanism
changes from recombination type processes to the coalescence of free valence
quarks, we find that the Lambda^0 polarization depends on the relative
contribution of each process to the total number of Lambda^0's produced in the
collision. To describe the polarization of Lambda^0's in nuclear collisions for
densities below the critical density for the QGP formation, we use the
DeGrand-Miettinen model corrected for the effects introduced by multiple
scattering of the produced Lambda^0 within the nuclear environment.Comment: 9 pages, 6 figures, uses ReVTeX and epsfig.st
The hyperon-nucleon interaction: conventional versus effective field theory approach
Hyperon-nucleon interactions are presented that are derived either in the
conventional meson-exchange picture or within leading order chiral effective
field theory. The chiral potential consists of one-pseudoscalar-meson exchanges
and non-derivative four-baryon contact terms. With regard to meson-exchange
hyperon-nucleon models we focus on the new potential of the Juelich group,
whose most salient feature is that the contributions in the scalar--isoscalar
(\sigma) and vector--isovector (\rho) exchange channels are constrained by a
microscopic model of correlated \pi\pi and KKbar exchange.Comment: 28 pages, 8 figures, submitted to Lecture Notes in Physic
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