516 research outputs found
Evidence for a bi-partition of the Younger Dryas Stadial in East Asia associated with inversed climate characteristics compared to Europe
The Younger Dryas Stadial (YDS) was an episode of northern hemispheric cooling which occurred within the Last Glacial Interglacial Transition (LGIT). A major driver for the YDS climate was a weakening of the Atlantic Meridional Overturning Circulation (AMOC). It has been inferred that the AMOC began to strengthen mid-YDS, producing a bipartite structure of the YDS in records from continental Europe. These records imply that the polar front and westerlies shifted northward, producing a warmer second phase of the YDS in Europe. Here we present multi-proxy data from the sediments of Lake Suigetsu (Japan), as evidence that a related bi-partition of the YDS also occurred in East Asia. Besides showing for the first time that the bi-partition was not limited to the North Atlantic/European region, the data also imply a climatic dipole between Europe and East Asia since the cold-warm characteristics are reversed at Lake Suigetsu. We suggest that changes in eastward moisture transport from the North Atlantic are the primary mechanism by which the teleconnection can be explained
The Health Belief Model Applied to Understanding Diabetes Regimen Compliance
Inadequate adherence to prescribed treatment plans is perhaps the most serious obstacle to achieving success ful therapeutic outcomes, and non compliance by diabetic patients is no exception. This is partly based on pa tients' realization that compliance does not necessarily result in lack of illness. A psychosocial framework for under standing patient compliance is the Health Belief Model, which is based upon the value an individual places on the identified goal and the likelihood that compliance will achieve that goal. This Model has been useful to explain noncompliance, to make an "educa tional diagnosis," and for designing compliance-enhancing interventions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68410/2/10.1177_014572178501100108.pd
Growth responses of Ailanthus altissima seedlings to SO2
Growth of Ailanthus altissima (Mill.) Swingle seedlings exposed to various levels of sulphur dioxide (SO2) was observed. Exposure for 1 or 2 weeks at 260 [mu]gm-3 (0[middle dot]1 ppm) or 520 [mu]g m-3 (0[middle dot]2 ppm) of SO2 significantly (p 2 concentration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24357/1/0000626.pd
Estimation of useful-stage energy returns on investment for fossil fuels and implications for renewable energy systems
The net energy implications of the energy transition have so far been analysed at best at the final energy stage. Here we argue that expanding the analysis to the useful stage is crucial. We estimate fossil fuelsÊŒ useful-stage energy returns on investment (EROIs) over the period 1971â2020, globally and nationally, and disaggregate EROIs by end use. We find that fossil fuelsÊŒ useful-stage EROIs (~3.5:1) are considerably lower than at the final stage (~8.5:1), due to low final-to-useful efficiencies. Further, we estimate the final-stage EROI for which electricity-yielding renewable energy would deliver the same net useful energy as fossil fuels (EROI equivalent) to be approximately 4.6:1. The EROIs of electricity-yielding renewable energy systems, based on published estimations, are found to be higher than the determined EROI equivalent, even considering the effects of intermittency under a range of energy transition scenarios. Results suggest that the energy transition may happen without a decline in net useful energy, countering the view that renewable energy systems cannot replace fossil fuels without incurring a substantial energy penalty
MIPAS temperature from the stratosphere to the lower thermosphere: Comparison of vM21 with ACE-FTS, MLS, OSIRIS, SABER, SOFIE and lidar measurements
© Author(s) 2014. We present vM21 MIPAS temperatures from the lower stratosphere to the lower thermosphere, which cover all optimized resolution measurements performed by MIPAS in the middle-atmosphere, upper-atmosphere and noctilucent-cloud modes during its lifetime, i.e., from January 2005 to April 2012. The main upgrades with respect to the previous version of MIPAS temperatures (vM11) are the update of the spectroscopic database, the use of a different climatology of atomic oxygen and carbon dioxide, and the improvement in important technical aspects of the retrieval setup (temperature gradient along the line of sight and offset regularizations, apodization accuracy). Additionally, an updated version of ESA-calibrated L1b spectra (5.02/5.06) is used. The vM21 temperatures correct the main systematic errors of the previous version because they provide on average a 1-2 K warmer stratopause and middle mesosphere, and a 6-10 K colder mesopause (except in high-latitude summers) and lower thermosphere. These lead to a remarkable improvement in MIPAS comparisons with ACE-FTS, MLS, OSIRIS, SABER, SOFIE and the two Rayleigh lidars at Mauna Loa and Table Mountain, which, with a few specific exceptions, typically exhibit differences smaller than 1 K below 50 km and than 2 K at 50-80 km in spring, autumn and winter at all latitudes, and summer at low to midlatitudes. Differences in the high-latitude summers are typically smaller than 1 K below 50 km, smaller than 2 K at 50-65 km and 5 K at 65-80 km. Differences between MIPAS and the other instruments in the mid-mesosphere are generally negative. MIPAS mesopause is within 4 K of the other instruments measurements, except in the high-latitude summers, when it is within 5-10 K, being warmer there than SABER, MLS and OSIRIS and colder than ACE-FTS and SOFIE. The agreement in the lower thermosphere is typically better than 5 K, except for high latitudes during spring and summer, when MIPAS usually exhibits larger vertical gradients.M. Garcia-Comas was financially supported by the Ministry of Economy and Competitiveness (MINECO) through its >Ramon y Cajal> subprogram. The IAA team was supported by the Spanish MINECO, through project AYA2011-23552, the CONSOLIDER program CSD2009-00038, and EC FEDER funds. Funding for ACE comes primarily from the Canadian Space Agency. We thank ESA for providing MIPAS level-1b data.Peer Reviewe
MIPAS temperature from the stratosphere to the lower thermosphere: Comparison of vM21 with ACE-FTS, MLS, OSIRIS, SABER, SOFIE and lidar measurements
We present vM21 MIPAS temperatures from the lower stratosphere to the lower
thermosphere, which cover all optimized resolution measurements performed by
MIPAS in the middle-atmosphere, upper-atmosphere and noctilucent-cloud modes
during its lifetime, i.e., from January 2005 to April 2012. The main upgrades
with respect to the previous version of MIPAS temperatures (vM11) are the
update of the spectroscopic database, the use of a different climatology of
atomic oxygen and carbon dioxide, and the improvement in important technical
aspects of the retrieval setup (temperature gradient along the line of sight
and offset regularizations, apodization accuracy). Additionally, an updated
version of ESA-calibrated L1b spectra (5.02/5.06) is used. The vM21
temperatures correct the main systematic errors of the previous version
because they provide on average a 1â2 K warmer stratopause and middle
mesosphere, and a 6â10 K colder mesopause (except in high-latitude summers)
and lower thermosphere. These lead to a remarkable improvement in MIPAS
comparisons with ACE-FTS, MLS, OSIRIS, SABER, SOFIE and the two Rayleigh
lidars at Mauna Loa and Table Mountain, which, with a few specific exceptions,
typically exhibit differences smaller than 1 K below 50 km and than 2 K at
50â80 km in spring, autumn and winter at all latitudes, and summer at low to
midlatitudes. Differences in the high-latitude summers are typically smaller
than 1 K below 50 km, smaller than 2 K at 50â65 km and 5 K at
65â80 km. Differences between MIPAS and the other instruments in the
mid-mesosphere are generally negative. MIPAS mesopause is within 4 K of the
other instruments measurements, except in the high-latitude summers, when it
is within 5â10 K, being warmer there than SABER, MLS and OSIRIS and colder
than ACE-FTS and SOFIE. The agreement in the lower thermosphere is typically
better than 5 K, except for high latitudes during spring and summer, when
MIPAS usually exhibits larger vertical gradients
Genomic adaptations of Campylobacter jejuni to long-term human colonization
Background
Campylobacter is a genus of bacteria that has been isolated from the gastrointestinal tract of humans and animals, and the environments they inhabit around the world. Campylobacter adapt to new environments by changes in their gene content and expression, but little is known about how they adapt to long-term human colonization. In this study, the genomes of 31 isolates from a New Zealand patient and 22 isolates from a United Kingdom patient belonging to Campylobacter jejuni sequence type 45 (ST45) were compared with 209 ST45 genomes from other sources to identify the mechanisms by which Campylobacter adapts to long-term human colonization. In addition, the New Zealand patient had their microbiota investigated using 16S rRNA metabarcoding, and their level of inflammation and immunosuppression analyzed using biochemical tests, to determine how Campylobacter adapts to a changing gastrointestinal tract.
Results
There was some evidence that long-term colonization led to genome degradation, but more evidence that Campylobacter adapted through the accumulation of non-synonymous single nucleotide polymorphisms (SNPs) and frameshifts in genes involved in cell motility, signal transduction and the major outer membrane protein (MOMP). The New Zealand patient also displayed considerable variation in their microbiome, inflammation and immunosuppression over five months, and the Campylobacter collected from this patient could be divided into two subpopulations, the proportion of which correlated with the amount of gastrointestinal inflammation.
Conclusions
This study demonstrates how genomics, phylogenetics, 16S rRNA metabarcoding and biochemical markers can provide insight into how Campylobacter adapts to changing environments within human hosts. This study also demonstrates that long-term human colonization selects for changes in Campylobacter genes involved in cell motility, signal transduction and the MOMP; and that genetically distinct subpopulations of Campylobacter evolve to adapt to the changing gastrointestinal environment
Application of isotope-selective non-dispersive infrared spectrometry for the evaluation of the 13C-urea breath test: comparison with three concordant methods
Chronic probiotic supplementation with or without glutamine does not influence the eHsp72 response to a multi-day ultra-endurance exercise event
Probiotic and glutamine supplementation increases tissue Hsp72, but their influence on extracellular Hsp72 (eHsp72) has not been investigated. The aim of this study was to investigate the effect of chronic probiotic supplementation, with or without glutamine, on eHsp72 concentration before and after an ultramarathon. Thirty-two participants were split into three independent groups, where they ingested probiotic capsules (PRO, n = 11), probiotic + glutamine powder (PGLn, n = 10) or no supplementation (CON, n = 11), over a 12-week period prior to commencement of the Marathon des Sables (MDS). eHsp72 concentration in the plasma was measured at baseline, 7 days pre-race, 6-8 hours post-race, and 7 days post-race. The MDS increased eHsp72 concentrations by 124% (F1,3 = 22.716, p 0.05). In conclusion, the MDS caused a substantial increase in eHsp72 concentration indicating high levels of systemic stress. However, chronic PRO or PGLn supplementation did not effect eHsp72 compared to control pre- or post-MDS. Given the role of eHsp72 in immune activation, the commercially available supplements used in this study are unlikely to influence this cascade
Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA
An investigation of the hadronic final state in diffractive and
non--diffractive deep--inelastic electron--proton scattering at HERA is
presented, where diffractive data are selected experimentally by demanding a
large gap in pseudo --rapidity around the proton remnant direction. The
transverse energy flow in the hadronic final state is evaluated using a set of
estimators which quantify topological properties. Using available Monte Carlo
QCD calculations, it is demonstrated that the final state in diffractive DIS
exhibits the features expected if the interaction is interpreted as the
scattering of an electron off a current quark with associated effects of
perturbative QCD. A model in which deep--inelastic diffraction is taken to be
the exchange of a pomeron with partonic structure is found to reproduce the
measurements well. Models for deep--inelastic scattering, in which a
sizeable diffractive contribution is present because of non--perturbative
effects in the production of the hadronic final state, reproduce the general
tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil
- âŠ