680 research outputs found
Using theory of change to achieve impact in AAS
The CGIAR Strategy and Results Framework sets out four system level outcomes (SLOs), namely: reducing rural poverty, improving food security, improving nutrition and health and sustainable management of natural resources. In pursuit of these objectives the CGIAR has developed a set of sixteen CGIAR Research Programs (CRPs), each of which is expected to make specific contributions to a range of intermediate development outcomes (IDOs) linked to the SLOs. As part of this work the CRPs are developing impact pathways and theories of change designed to explain how the programs will achieve IDOs. The purpose of the present paper is to explain the approach that the CRP on Aquatic Agricultural Systems (AAS) is taking to using these programmatic tools to help achieve impact
The Family Name as Socio-Cultural Feature and Genetic Metaphor: From Concepts to Methods
A recent workshop entitled The Family Name as Socio-Cultural Feature and Genetic Metaphor: From Concepts to Methods was held in Paris in December 2010, sponsored by the French National Centre for Scientific Research (CNRS) and by the journal Human Biology. This workshop was intended to foster a debate on questions related to the family names and to compare different multidisciplinary approaches involving geneticists, historians, geographers, sociologists and social anthropologists. This collective paper presents a collection of selected communications
Publisher Correction: Liquid phase blending of metal-organic frameworks
The original version of this Article contained an error in Figure 1b, where the blue ‘(ZIF-4-Zn)0.5 (ZIF-62)0.5 blend’ data curve was omitted from the enthalpy response plot. This has now been corrected in both the PDF and HTML versions of the Article
A Study of Cosmic Ray Composition in the Knee Region using Multiple Muon Events in the Soudan 2 Detector
Deep underground muon events recorded by the Soudan 2 detector, located at a
depth of 2100 meters of water equivalent, have been used to infer the nuclear
composition of cosmic rays in the "knee" region of the cosmic ray energy
spectrum. The observed muon multiplicity distribution favors a composition
model with a substantial proton content in the energy region 800,000 -
13,000,000 GeV/nucleus.Comment: 38 pages including 11 figures, Latex, submitted to Physical Review
Search for Nucleon Decays induced by GUT Magnetic Monopoles with the MACRO Experiment
The interaction of a Grand Unification Magnetic Monopole with a nucleon can
lead to a barion-number violating process in which the nucleon decays into a
lepton and one or more mesons (catalysis of nucleon decay). In this paper we
report an experimental study of the effects of a catalysis process in the MACRO
detector. Using a dedicated analysis we obtain new magnetic monopole (MM) flux
upper limits at the level of for
, based on the search for
catalysis events in the MACRO data. We also analyze the dependence of the MM
flux limit on the catalysis cross section.Comment: 12 pages, Latex, 10 figures and 2 Table
Neutrino astronomy with the MACRO detector
High energy gamma ray astronomy is now a well established field and several
sources have been discovered in the region from a few GeV up to several TeV. If
sources involving hadronic processes exist, the production of photons would be
accompanied by neutrinos too. Other possible neutrino sources could be related
to the annihilation of WIMPs at the center of galaxies with black holes.
We present the results of a search for point-like sources using 1100
upward-going muons produced by neutrino interactions in the rock below and
inside the MACRO detector in the underground Gran Sasso Laboratory. These data
show no evidence for a possible neutrino point-like source or for possible
correlations between gamma ray bursts and neutrinos. They have been used to set
flux upper limits for candidate point-like sources which are in the range
10^-14-10^-15 cm-2 s-1.Comment: 37 pages, 15 figures, replacement due to a typo in tab. 6, AASLaTex,
submitted to Ap
Search for massive rare particles with MACRO
Massive rare particles have been searched for in the penetrating cosmic
radiation using the MACRO apparatus at the Gran Sasso National Laboratories.
Liquid scintillators, streamer tubes and nuclear track detectors have been used
to search for magnetic monopoles (MMs).
Based on no observation of such signals, stringent flux limits are
established for MMs as slow as a few 10^(-5)c. The methods based on the
scintillator and on the nuclear track subdetectors were also applied to search
for nuclearites. Preliminary results of the searches for charged Q-balls are
also presented.Comment: 20 pages, 9 EPS figures included with epsfi
The primary cosmic ray composition between 10**15 and 10**16 eV from Extensive Air Showers electromagnetic and TeV muon data
The cosmic ray primary composition in the energy range between 10**15 and
10**16 eV, i.e., around the "knee" of the primary spectrum, has been studied
through the combined measurements of the EAS-TOP air shower array (2005 m
a.s.l., 10**5 m**2 collecting area) and the MACRO underground detector (963 m
a.s.l., 3100 m w.e. of minimum rock overburden, 920 m**2 effective area) at the
National Gran Sasso Laboratories. The used observables are the air shower size
(Ne) measured by EAS-TOP and the muon number (Nmu) recorded by MACRO. The two
detectors are separated on average by 1200 m of rock, and located at a
respective zenith angle of about 30 degrees. The energy threshold at the
surface for muons reaching the MACRO depth is approximately 1.3 TeV. Such muons
are produced in the early stages of the shower development and in a kinematic
region quite different from the one relevant for the usual Nmu-Ne studies. The
measurement leads to a primary composition becoming heavier at the knee of the
primary spectrum, the knee itself resulting from the steepening of the spectrum
of a primary light component (p, He). The result confirms the ones reported
from the observation of the low energy muons at the surface (typically in the
GeV energy range), showing that the conclusions do not depend on the production
region kinematics. Thus, the hadronic interaction model used (CORSIKA/QGSJET)
provides consistent composition results from data related to secondaries
produced in a rapidity region exceeding the central one. Such an evolution of
the composition in the knee region supports the "standard" galactic
acceleration/propagation models that imply rigidity dependent breaks of the
different components, and therefore breaks occurring at lower energies in the
spectra of the light nuclei.Comment: Submitted to Astroparticle Physic
Observation of the Shadowing of Cosmic Rays by the Moon using a Deep Underground Detector
Using data collected by the MACRO experiment during the years 1989-1996, we
show evidence for the shadow of the moon in the underground cosmic ray flux
with a significance of 3.6 sigma. This detection of the shadowing effect is the
first by an underground detector. A maximum-likelihood analysis is used to
determine that the angular resolution of the apparatus is 0.9+/-0.3 degrees.
These results demonstrate MACRO's capabilities as a muon telescope by
confirming its absolute pointing ability and quantifying its angular
resolution.Comment: 14 pages, 8 figures Submitted to Phys. Rev.
Limits on dark matter WIMPs using upward-going muons in the MACRO detector
We perform an indirect search for Weakly Interacting Massive Particles
(WIMPs) using the MACRO detector to look for neutrino-induced upward-going
muons resulting from the annihilation of WIMPs trapped in the Sun and Earth.
The search is conducted in various angular cones centered on the Sun and Earth
to accommodate a range of WIMP masses. No significant excess over the
background from atmospheric neutrinos is seen and limits are placed on the
upward-going muon fluxes from Sun and Earth. These limits are used to constrain
neutralino particle parameters from supersymmetric theory, including those
suggested by recent results from DAMA/NaI.Comment: 14 pages, 7 figures, submitted to Phys. Rev.
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