964 research outputs found
Farm-gate nitrogen balances on intensive dairy farms in the south west of Ireland
peer-reviewedNitrogen management and farm-gate N balances were evaluated on 21 intensive dairy farms in the south west of Ireland for each of four years (2003 to 2006). The mean annual stocking density was equivalent to 202 kg/ha (s.d. 29.6) of N excreted by livestock on the farm. The mean annual farm-gate N surplus (imports – exports) declined between 2003 and 2006 (277 to 232 kg/ha, s.e. 6.8; P < 0.001) due to a decline in annual N imports (fertilizer, feed and imported manures; 335 to 288 kg/ha, s.e. 6.9; P < 0.001).
Overall annual fertilizer N use on the farms decreased during the study period (266 to 223 kg/ha, s.e. 6.5; P < 0.001) mainly due to lower inputs for the first application in spring and for the production of first-cut silage. These decreases were partly offset by applying more slurry in spring for early grazing and for first-cut silage. The introduction of white clover resulted in lower N imports on four farms. Export of N from farms was unaffected by reductions in N imports. The mean efficiency of N use tended to increase over time (0.18 in 2003 to 0.20 in 2006). The large variation in quantities of fertilizer N applied on farms with similar stocking densities suggests potential for further improvements in the efficiency of N use. In terms of fertilizer N use, complying with S.I. No. 378 of 2006 did not require major changes in the N management practiceson 19 of the farms.This project was part-funded by the European Research and Development Fund under INTERREG IIIB: Green Dairy Project N° 100 and partly by the Dairy Levy. Financial support for post-graduate students involved in this study was provided by the Teagasc Walsh Fellowship Scheme
Bounded-time fault-tolerant rule-based systems
Two systems concepts are introduced: bounded response-time and self-stabilization in the context of rule-based programs. These concepts are essential for the design of rule-based programs which must be highly fault tolerant and perform in a real time environment. The mechanical analysis of programs for these two properties is discussed. The techniques are used to analyze a NASA application
Using message logs and resource use data for cluster failure diagnosis
Failure diagnosis for large compute clusters using only message logs is known to be incomplete. Recent availability of resource use data provides another potentially useful source of data for failure detection and diagnosis. Early work combining message logs and resource use data for failure diagnosis has shown promising results. This paper describes the CRUMEL framework which implements a new approach to combining rationalized message logs and resource use data for failure diagnosis. CRUMEL identifies patterns of errors and resource use and correlates these patterns by time with system failures. Application of CRUMEL to data from the Ranger supercomputer has yielded improved diagnoses over previous research. CRUMEL has: (i) showed that more events correlated with system failures can only be identified by applying different correlation algorithms, (ii) confirmed six groups of errors, (iii) identified Lustre I/O resource use counters which are correlated with occurrence of Lustre faults which are potential flags for online detection of failures, (iv) matched the dates of correlated error events and correlated resource use with the dates of compute node hangups and (v) identified two more error groups associated with compute node hang-ups. The pre-processed data will be put on the public domain in September, 2016
Replication and exploratory analysis of 24 candidate risk polymorphisms for neural tube defects.
BackgroundNeural tube defects (NTDs), which are among the most common congenital malformations, are influenced by environmental and genetic factors. Low maternal folate is the strongest known contributing factor, making variants in genes in the folate metabolic pathway attractive candidates for NTD risk. Multiple studies have identified nominally significant allelic associations with NTDs. We tested whether associations detected in a large Irish cohort could be replicated in an independent population.MethodsReplication tests of 24 nominally significant NTD associations were performed in racially/ethnically matched populations. Family-based tests of fifteen nominally significant single nucleotide polymorphisms (SNPs) were repeated in a cohort of NTD trios (530 cases and their parents) from the United Kingdom, and case-control tests of nine nominally significant SNPs were repeated in a cohort (190 cases, 941 controls) from New York State (NYS). Secondary hypotheses involved evaluating the latter set of nine SNPs for NTD association using alternate case-control models and NTD groupings in white, African American and Hispanic cohorts from NYS.ResultsOf the 24 SNPs tested for replication, ADA rs452159 and MTR rs10925260 were significantly associated with isolated NTDs. Of the secondary tests performed, ARID1A rs11247593 was associated with NTDs in whites, and ALDH1A2 rs7169289 was associated with isolated NTDs in African Americans.ConclusionsWe report a number of associations between SNP genotypes and neural tube defects. These associations were nominally significant before correction for multiple hypothesis testing. These corrections are highly conservative for association studies of untested hypotheses, and may be too conservative for replication studies. We therefore believe the true effect of these four nominally significant SNPs on NTD risk will be more definitively determined by further study in other populations, and eventual meta-analysis
Budget Perspectives 2013. RESEARCH SERIES NUMBER 28 September 2012
The annual Budget Perspectives Conference provides a forum for discussing key
public policy issues of both immediate and longer term concern. In the context of
the current fiscal and economic crisis, research insights are needed at both the
macro and micro level. The former are central to understanding and managing the
significant reductions in the budget deficit needed to put Ireland's public finances on
a sustainable footing. The latter are essential because a successful budgetary
adjustment requires restructuring of both public expenditure and taxation. This in
turn requires that policy adjustments take full account of both efficiency and equity
issue and are seen to do so. The research papers presented at this year's annual
Budget Perspectives Conference continue in this tradition, providing an opportunity
for policymakers, social partners and researchers to engage with some of the major
current issues
Predicting university performance in psychology: the role of previous performance and discipline-specific knowledge
Recent initiatives to enhance retention and widen participation ensure it is crucial to understand the factors that predict students' performance during their undergraduate degree. The present research used Structural Equation Modeling (SEM) to test three separate models that examined the extent to which British Psychology students' A-level entry qualifications predicted: (1) their performance in years 1-3 of their Psychology degree, and (2) their overall degree performance. Students' overall A-level entry qualifications positively predicted performance during their first year and overall degree performance, but negatively predicted their performance during their third year. Additionally, and more specifically, students' A-level entry qualifications in Psychology positively predicted performance in the first year only. Such findings have implications for admissions tutors, as well as for students who have not studied Psychology before but who are considering applying to do so at university
The impact of Hurricane Sandy on the shoreface and inner shelf of Fire Island, New York : large bedform migration but limited erosion
© The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution.. The definitive version was published in Continental Shelf Research 98 (2015): 13-25, doi:10.1016/j.csr.2015.03.001.We investigate the impact of superstorm Sandy on the lower shoreface and inner shelf
offshore the barrier island system of Fire Island, NY using before-and-after surveys involving
swath bathymetry, backscatter and CHIRP acoustic reflection data. As sea level rises over the
long term, the shoreface and inner shelf are eroded as barrier islands migrate landward; large
storms like Sandy are thought to be a primary driver of this largely evolutionary process. The
“before” data were collected in 2011 by the U.S. Geological Survey as part of a long-term
investigation of the Fire Island barrier system. The “after” data were collected in January, 2013,
~two months after the storm. Surprisingly, no widespread erosional event was observed. Rather,
the primary impact of Sandy on the shoreface and inner shelf was to force migration of major
bedforms (sand ridges and sorted bedforms) 10’s of meters WSW alongshore, decreasing in
migration distance with increasing water depth. Although greater in rate, this migratory behavior
is no different than observations made over the 15-year span prior to the 2011 survey.
Stratigraphic observations of buried, offshore-thinning fluvial channels indicate that long-term
erosion of older sediments is focused in water depths ranging from the base of the shoreface
(~13-16 m) to ~21 m on the inner shelf, which is coincident with the range of depth over which
sand ridges and sorted bedforms migrated in response to Sandy. We hypothesize that bedform
migration regulates erosion over these water depths and controls the formation of a widely
observed transgressive ravinement; focusing erosion of older material occurs at the base of the
stoss (upcurrent) flank of the bedforms. Secondary storm impacts include the formation of
ephemeral hummocky bedforms and the deposition of a mud event layer.This work was funded primarily by a rapid response grant from the Jackson
School of Geosciences, The University of Texas/Austi
Neuroinflammation in the normal-appearing white matter (NAWM) of the multiple sclerosis brain causes abnormalities at the nodes of Ranvier
Changes to the structure of nodes of Ranvier in the normal-appearing white matter (NAWM) of multiple sclerosis (MS) brains are associated with chronic inflammation. We show that the paranodal domains in MS NAWM are longer on average than control, with Kv1.2 channels dislocated into the paranode. These pathological features are reproduced in a model of chronic meningeal inflammation generated by the injection of lentiviral vectors for the lymphotoxin-α (LTα) and interferon-γ (IFNγ) genes. We show that tumour necrosis factor (TNF), IFNγ, and glutamate can provoke paranodal elongation in cerebellar slice cultures, which could be reversed by an N-methyl-D-aspartate (NMDA) receptor blocker. When these changes were inserted into a computational model to simulate axonal conduction, a rapid decrease in velocity was observed, reaching conduction failure in small diameter axons. We suggest that glial cells activated by pro-inflammatory cytokines can produce high levels of glutamate, which triggers paranodal pathology, contributing to axonal damage and conduction deficits
Shiga Toxin–producing Escherichia coli Strains Negative for Locus of Enterocyte Effacement
The ehx plasmids of these strains are highly related, which suggests acquisition of the large plasmid was central to the strains’ emergence
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