1,166 research outputs found
Terrestrial Laser Scanning to Detect Liana Impact on Forest Structure
Tropical forests are currently experiencing large-scale structural changes, including an increase in liana abundance and biomass. Higher liana abundance results in reduced tree growth and increased tree mortality, possibly playing an important role in the global carbon cycle. Despite the large amount of data currently available on lianas, there are not many quantitative studies on the influence of lianas on the vertical structure of the forest. We study the potential of terrestrial laser scanning (TLS) in detecting and quantifying changes in forest structure after liana cutting using a small scale removal experiment in two plots (removal plot and non-manipulated control plot) in a secondary forest in Panama. We assess the structural changes by comparing the vertical plant profiles and Canopy Height Models (CHMs) between pre-cut and post-cut scans in the removal plot. We show that TLS is able to detect the local structural changes in all the vertical strata of the plot caused by liana removal. Our study demonstrates the reproducibility of the TLS derived metrics for the same location confirming the applicability of TLS for continuous monitoring of liana removal plots to study the long-term impacts of lianas on forest structure. We therefore recommend to use TLS when implementing new large scale liana removal experiments, as the impact of lianas on forest structure will determine the aboveground competition for light between trees and lianas, which has important implications for the global carbon cycle
Lianas in silico, ecological insights from a model of structural parasitism
Tropical forests are a critical component of the Earth system, storing half of the global forest carbon stocks and accounting for a third of terrestrial photosynthesis. Lianas are structural parasites that can substantially reduce the carbon sequestration capacity of these forests. Simulations of this peculiar growth form have only recently started and a single vegetation model included lianas so far. In this work we present a new liana implementation within the individual based model Formind. Initial tests indicate high structural realism both horizontal and vertical. In particular, we benchmarked the model against empirical observations of size distribution, mean liana cluster size and vertical leaf distribution for the Paracou site in French Guiana. Our model predicted a reduction of above-ground biomass between 10% for mature stands to 45% for secondary plots upon inclusion of lianas in the simulations. The reduced biomass was the result of a lower productivity due to a combination of lower tree photosynthesis and high liana respiration. We evaluated structural metrics (LAI, basal area, mean tree-height) and carbon fluxes (GPP, respiration) by comparing simulations with and without lianas. At the equilibrium, liana productivity was 1.9tC ha y or 23% of the total GPP and the forest carbon stocks were between 5% and 11% lower in simulations with lianas. We also highlight the main strengths and limitations of this new approach and propose new field measurements to further the understanding of liana ecology in a modelling framework
Italian validation of the Clinical Outcomes in Routine Evaluation-10 (CORE-10): a short measure for routine outcome monitoring in clinical practice
The customization of the intervention using patient feedback is an evidence based practice aimed at the continuous evaluation, during treatment, of the patientâs change at a clinical level. There are few easy to use tools for common assessment of psychological distress, designed to be used for screening and during treatment to monitor progress. The Clinical Outcomes in Routine Evaluation-10 (CORE-10) is definitely one of them. Thus, the aim of the present study was to examine the psychometric properties of the Italian version of the CORE-10. A sample of 548 participants was recruited in the study and filled out a battery of measures. The internal validity of the CORE 10 was investigated through a confirmatory factor analysis which evidenced a good fit to the data, suggesting a unidimensional factorial structure of the measure. Further, the scale had a good internal reliability and was significantly associated with other measures of distress, interpersonal problems, well-being, and insecure attachment. Fi- nally, it showed excellent diagnostic accuracy, as well as intrinsic and post test diagnostics. Given its validity and reliability, the CORE 10 may be adopted by Italian speaking psychotherapists and researchers to evaluate the outcomes of mental health interventions as well as to track the changes over time in psychological distress among patients
Signal modeling of high-purity Ge detectors with a small read-out electrode and application to neutrinoless double beta decay search in Ge-76
The GERDA experiment searches for the neutrinoless double beta decay of Ge-76
using high-purity germanium detectors enriched in Ge-76. The analysis of the
signal time structure provides a powerful tool to identify neutrinoless double
beta decay events and to discriminate them from gamma-ray induced backgrounds.
Enhanced pulse shape discrimination capabilities of "Broad Energy Germanium"
detectors with a small read-out electrode have been recently reported. This
paper describes the full simulation of the response of such a detector,
including the Monte Carlo modeling of radiation interaction and subsequent
signal shape calculation. A pulse shape discrimination method based on the
ratio between the maximum current signal amplitude and the event energy applied
to the simulated data shows quantitative agreement with the experimental data
acquired with calibration sources. The simulation has been used to study the
survival probabilities of the decays which occur inside the detector volume and
are difficult to assess experimentally. Such internal decay events are produced
by the cosmogenic radio-isotopes Ge-68 and Co-60 and the neutrinoless double
beta decay of Ge-76. Fixing the experimental acceptance of the double escape
peak of the 2.614 MeV photon to 90%, the estimated survival probabilities at
Qbb = 2.039 MeV are (86+-3)% for Ge-76 neutrinoless double beta decays,
(4.5+-0.3)% for the Ge-68 daughter Ga-68, and (0.9+0.4-0.2)% for Co-60 decays.Comment: 27 pages, 17 figures. v2: fixed typos and references. Submitted to
JINS
Modeling the Impact of Liana Infestation on The Demography and Carbon Cycle of Tropical Forests
There is mounting empirical evidence that lianas affect the carbon cycle of tropical forests. However, no single vegetation model takes into account this growth form, although such efforts could greatly improve the predictions of carbon dynamics in tropical forests. In this study, we incorporated a novel mechanistic representation of lianas in a dynamic global vegetation model (the Ecosystem Demography Model). We developed a lianaâspecific plant functional type and mechanisms representing lianaâtree interactions (such as light competition, lianaâspecific allometries, and attachment to host trees) and parameterized them according to a comprehensive literature metaâanalysis. We tested the model for an oldâgrowth forest (Paracou, French Guiana) and a secondary forest (Gigante Peninsula, Panama). The resulting model simulations captured many features of the two forests characterized by different levels of liana infestation as revealed by a systematic comparison of the model outputs with empirical data, including local census data from forest inventories, eddy flux tower data, and terrestrial laser scannerâderived forest vertical structure. The inclusion of lianas in the simulations reduced the secondary forest net productivity by up to 0.46 tC haâ1 yearâ1, which corresponds to a limited relative reduction of 2.6% in comparison with a reference simulation without lianas. However, this resulted in significantly reduced accumulated aboveâground biomass after 70 years of regrowth by up to 20 tC/ha (19% of the reference simulation). Ultimately, the simulated negative impact of lianas on the total biomass was almost completely cancelled out when the forest reached an oldâgrowth successional stage. Our findings suggest that lianas negatively influence the forest potential carbon sink strength, especially for young, disturbed, lianaârich sites. In light of the critical role that lianas play in the profound changes currently experienced by tropical forests, this new model provides a robust numerical tool to forecast the impact of lianas on tropical forest carbon sinks
Efficacy of simultaneous vaccination with EnterisolÂź Ileitis and IngelvacÂź CircoFLEXTM in a Swiss breeding farm
This study explores administration of two piglet vaccines as compared to the mono- and adjuvant-application. A vaccine against the Porcine Circovirus Type 2 (PCV2) cap protein subunit and a vaccine with attenuated live culture against Lawsonia (L.) intracellularis were applied to piglets aged 23.5 days on average. 1'405 animals were divided randomly into four groups. One piglet group was immunized with both vaccines while two other groups were immunized with a combination of one vaccine and adjuvants of alternate vaccination protocol and vice versa. These piglet groups were also compared to a control group supplemented with both adjuvants only. During fattening, pigs, which were simultaneously immunized with Enterisol(Âź) Ileitis and Ingelvac(Âź) CircoFLEX(TM) vaccine, gained significantly more weight (792 g/day) when compared to piglet groups mono-vaccinated with IngelvacÂź CircoFLEXTM (772 g/day) or either with EnterisolÂź Ileitis (774 g/day). Moreover, immunized piglet groups showed significantly higher daily weight gain when compared to adjuvants only inoculated control group (751 g/day). Additionally, during fattening the control group displayed higher mortality (6,3 %) than the three vaccinated groups (Ingelvac(Âź) CircoFLEX(TM) 2,5 %, Enterisol(Âź) Ileitis 2,3 % and the combination of both vaccines 1,1 %). These data imply that simultaneous immunization with PCV2- and L. intracellularis specific vaccines positively benefit piglet growth observed by an additive effect on growth parameters in farms harboring both pathogens. Return of investment was calculated of 2.10 on the additional Enterisol(Âź) Ileitis vaccination
Deep inelastic production at HERA in the -factorization approach and its consequences for the nonrelativistic QCD
In the framework of the -factorization approach, we analyse the
inclusive and inelastic production of particles in deep inelastic
scattering. We take into account both colour-singlet and colour-octet
production channels. We inspect the sensitivity of theoretical predictions to
the choice of model parameters. Our theoretical results agree reasonably well
with recent experimental data collected by the collaboration H1 at HERA.Comment: 14 pages, 6 figure
Prospect for Charge Current Neutrino Interactions Measurements at the CERN-PS
Tensions in several phenomenological models grew with experimental results on
neutrino/antineutrino oscillations at Short-Baseline (SBL) and with the recent,
carefully recomputed, antineutrino fluxes from nuclear reactors. At a
refurbished SBL CERN-PS facility an experiment aimed to address the open issues
has been proposed [1], based on the technology of imaging in ultra-pure
cryogenic Liquid Argon (LAr). Motivated by this scenario a detailed study of
the physics case was performed. We tackled specific physics models and we
optimized the neutrino beam through a full simulation. Experimental aspects not
fully covered by the LAr detection, i.e. the measurements of the lepton charge
on event-by-event basis and their energy over a wide range, were also
investigated. Indeed the muon leptons from Charged Current (CC) (anti-)neutrino
interactions play an important role in disentangling different phenomenological
scenarios provided their charge state is determined. Also, the study of muon
appearance/disappearance can benefit of the large statistics of CC muon events
from the primary neutrino beam. Results of our study are reported in detail in
this proposal. We aim to design, construct and install two Spectrometers at
"NEAR" and "FAR" sites of the SBL CERN-PS, compatible with the already proposed
LAr detectors. Profiting of the large mass of the two Spectrometers their
stand-alone performances have also been exploited.Comment: 70 pages, 38 figures. Proposal submitted to SPS-C, CER
Flux Modulations seen by the Muon Veto of the GERDA Experiment
The GERDA experiment at LNGS of INFN is equipped with an active muon veto.
The main part of the system is a water Cherenkov veto with 66~PMTs in the water
tank surrounding the GERDA cryostat. The muon flux recorded by this veto shows
a seasonal modulation. Two effects have been identified which are caused by
secondary muons from the CNGS neutrino beam (2.2 %) and a temperature
modulation of the atmosphere (1.4 %). A mean cosmic muon rate of /(sm) was found in good agreement with other experiments at
LNGS at a depth of 3500~meter water equivalent.Comment: 7 pages, 6 figure
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