434 research outputs found
The use of semi-structured interviews for the characterisation of farmer irrigation practices
For the development of sustainable and realistic water security, generating
information on the behaviours, characteristics, and drivers of users, as well
as on the resource itself, is essential. In this paper we present a
methodology for collecting qualitative and quantitative data on water use
practices through semi-structured interviews. This approach facilitates the
collection of detailed information on actors' decisions in a convenient and
cost-effective manner. Semi-structured interviews are organised around a
topic guide, which helps lead the conversation in a standardised way while
allowing sufficient opportunity for relevant issues to emerge. In addition,
they can be used to obtain certain types of quantitative data. While not as
accurate as direct measurements, they can provide useful information on local
practices and users' insights. We present an application of the methodology
on farmer water use in two districts in the state of Uttar Pradesh in
northern India. By means of 100 farmer interviews, information was collected on
various aspects of irrigation practices, including irrigation water volumes,
irrigation cost, water source, and their spatial variability. Statistical
analyses of the information, along with data visualisation, are also
presented, indicating a significant variation in irrigation practices both within and
between districts. Our application shows that semi-structured interviews are
an effective and efficient method of collecting both qualitative and
quantitative information for the assessment of drivers, behaviours, and their
outcomes in a data-scarce region. The collection of this type of data could
significantly improve insights on water resources, leading to more realistic
management options and increased water security in the future
The use of semi-structured interviews for the characterisation of farmer irrigation practices
For the development of sustainable and realistic water security, generating information on the behaviours, characteristics, and drivers of users, as well as on the resource itself, is essential. In this paper we present a methodology for collecting qualitative and quantitative data on water use practices through semi-structured interviews. This approach facilitates the collection of detailed information on actors’ decisions in a convenient and cost-effective manner. Semi-structured interviews are organised around a topic guide, which helps lead the conversation in a standardised way while allowing sufficient opportunity for relevant issues to emerge. In addition, they can be used to obtain certain types of quantitative data. While not as accurate as direct measurements, they can provide useful information on local practices and users’ insights. We present an application of the methodology on farmer water use in two districts in the state of Uttar Pradesh in northern India. By means of 100 farmer interviews, information was collected on various aspects of irrigation practices, including irrigation water volumes, irrigation cost, water source, and their spatial variability. Statistical analyses of the information, along with data visualisation, are also presented, indicating a significant variation in irrigation practices both within and between districts. Our application shows that semi-structured interviews are an effective and efficient method of collecting both qualitative and quantitative information for the assessment of drivers, behaviours, and their outcomes in a data-scarce region. The collection of this type of data could significantly improve insights on water resources, leading to more realistic management options and increased water security in the future
Water-energy-food linkages in community smallholder irrigation schemes: Center pivot irrigation in Rwanda
Water, energy, and food are linked in intricate ways in irrigated agriculture and understanding the interplay of these components is crucial for sustainable and profitable crop production, particularly in smallholder setting such as in sub-Saharan Africa. This study evaluates water-energy-food linkages, engineering and economic performance, irrigation decision making, and challenges faced around water management in a community-based mechanized irrigation scheme in Rwanda. The research is the first to analyze such as scheme, which uses technology typically used by large farmers in a smallholder setting. The study investigates the variation in water requirements and the relationship and impacts of this variability on crop yield for the crops grown in the scheme: maize, French beans, and dry beans. Observed irrigation decision-making analyses demonstrate a lack of irrigation planning during growth stages and significant field-to-field variation in irrigation; this is linked to yield reduction in major crops. Results suggest that farmers irrigated only 31% of modeled irrigation water in dry beans and 27% of modeled irrigation water in maize. An econometric model assessment is used to understand the relationship between yield and energy inputs. A related policy analysis considers the impacts of changes in crop and water management on field-level profits and system-level financial sustainability. This study has implications for understanding irrigation policies in the context of the water-energy-food nexus and decision-making in Sub- Saharan Africa
New indication for a dichotomy in the interior structure of Uranus and Neptune from the application of modified shape and rotation data
Since the Voyager fly-bys of Uranus and Neptune, improved gravity field data
have been derived from long-term observations of the planets' satellite
motions, and modified shape and solid-body rotation periods were suggested. A
faster rotation period (-40 min) for Uranus and a slower rotation period
(+1h20) of Neptune compared to the Voyager data were found to minimize the
dynamical heights and wind speeds. We apply the improved gravity data, the
modified shape and rotation data, and the physical LM-R equation of state to
compute adiabatic three-layer structure models, where rocks are confined to the
core, and homogeneous thermal evolution models of Uranus and Neptune. We
present the full range of structure models for both the Voyager and the
modified shape and rotation data. In contrast to previous studies based solely
on the Voyager data or on empirical EOS, we find that Uranus and Neptune may
differ to an observationally significant level in their atmospheric heavy
element mass fraction Z1 and nondimensional moment of inertia, nI. For Uranus,
we find Z1 < 8% and nI=0.2224(1), while for Neptune Z1 < 65% and nI=0.2555(2)
when applying the modified shape and rotation data, while for the unmodified
data we compute Z1 < 17% and nI=0.230(1) for Uranus and Z1 < 54% and
nI=0.2410(8) for Neptune. In each of these cases, solar metallicity models
(Z1=0.015) are still possible. The cooling times obtained for each planet are
similar to recent calculations with the Voyager rotation periods: Neptune's
luminosity can be explained by assuming an adiabatic interior while Uranus
cools far too slowly. More accurate determinations of these planets' gravity
fields, shapes, rotation periods, atmospheric heavy element abundances, and
intrinsic luminosities are essential for improving our understanding of the
internal structure and evolution of icy planets.Comment: accepted to Planet. Space Sci., special editio
Mechanism of cell death resulting from DNA interstrand cross-linking in mammalian cells
DNA interstrand cross-links (ICLs) are critical cytotoxic lesions produced by cancer chemotherapeutic agents such as the nitrogen mustards and platinum drugs; however, the exact mechanism of ICL-induced cell death is unclear. Here, we show a novel mechanism of p53-independent apoptotic cell death involving prolonged cell-cycle (G2) arrest, ICL repair involving HR, transient mitosis, incomplete cytokinesis, and gross chromosomal abnormalities resulting from ICLs in mammalian cells. This characteristic ‘giant' cell death, observed by using time-lapse video microscopy, was reduced in ICL repair ERCC1- and XRCC3-deficient cells. Collectively, the results illustrate the coordination of ICL-induced cellular responses, including cell-cycle arrest, DNA damage repair, and cell death
Search for Kaluza-Klein Graviton Emission in Collisions at TeV using the Missing Energy Signature
We report on a search for direct Kaluza-Klein graviton production in a data
sample of 84 of \ppb collisions at = 1.8 TeV, recorded
by the Collider Detector at Fermilab. We investigate the final state of large
missing transverse energy and one or two high energy jets. We compare the data
with the predictions from a -dimensional Kaluza-Klein scenario in which
gravity becomes strong at the TeV scale. At 95% confidence level (C.L.) for
=2, 4, and 6 we exclude an effective Planck scale below 1.0, 0.77, and 0.71
TeV, respectively.Comment: Submitted to PRL, 7 pages 4 figures/Revision includes 5 figure
Measurement of the average time-integrated mixing probability of b-flavored hadrons produced at the Tevatron
We have measured the number of like-sign (LS) and opposite-sign (OS) lepton
pairs arising from double semileptonic decays of and -hadrons,
pair-produced at the Fermilab Tevatron collider. The data samples were
collected with the Collider Detector at Fermilab (CDF) during the 1992-1995
collider run by triggering on the existence of and candidates
in an event. The observed ratio of LS to OS dileptons leads to a measurement of
the average time-integrated mixing probability of all produced -flavored
hadrons which decay weakly, (stat.)
(syst.), that is significantly larger than the world average .Comment: 47 pages, 10 figures, 15 tables Submitted to Phys. Rev.
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