1,914 research outputs found
Noble gases and stable isotopes in a shallow aquifer in southern Michigan: Implications for noble gas paleotemperature reconstructions for cool climates
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95038/1/grl20200.pd
Noble gas composition in rainwater and associated weather patterns
This work represents the first comprehensive noble gas study in rainwater. It was carried out in southeast Michigan. Results show that all rainwater samples are in disequilibrium with surface conditions. Two noble gas patterns are identified. The first one, associated with low‐pressure systems, presence of fog and light rainfall, displays a relative Ar enrichment together with Ne, Kr, and Xe depletion. The second one, associated with the passage of frontal systems, displays a mass‐dependent depletion pattern. Precipitation is characterized by thunderstorms, heavy rainfall, and high cloud ceiling heights. A diffusion mass‐transfer model suggests that noble gas patterns originate from ice. Complete re‐equilibration with surface conditions should occur within hours. For the first time, this study establishes a direct correlation between the noble gas composition in rainwater and weather patterns and highlights their potential to identify timing and location of recharge in shallow aquifer systems where infiltration is rapid. Key Points Noble gases in rainwater are in disequilibrium with surface conditions Rainwater noble gas patterns are associated with weather conditions Ice is the starting point of rainwater formation in southeast MichiganPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/1/FigureS12.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/2/FigureS5.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/3/Supplementary_Text_3_revised2_Trackchanges.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/4/FigureS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/5/FigureS8.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/6/TableS2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/7/Supplementary_all.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/8/SuppText_2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/9/FigureS4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/10/FigureS9.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/11/TableS3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/12/FigureS7.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/13/TableS4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/14/SuppText_1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/15/FigureS10.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/16/Supplementary_Text_3_revised2_NOhighlight.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/17/FigureS3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/18/grl50610.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/19/FigureS6.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/20/FigureS11.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/21/TableS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/22/SuppText_4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/23/FigureS2.pd
Reply to comment by Klump et al. on “Noble gases and stable isotopes in a shallow aquifer in southern Michigan: Implications for noble gas paleotemperature reconstructions for cool climates”
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94860/1/grl22429.pd
Density fluctuations from warm inflation
Thermal fluctuations provide the main source of large scale density
perturbations in warm inflationary models of the early universe. For the first
time, general results are obtained for the power spectrum in the case when the
friction coefficient in the inflaton equation of motion depends on temperature.
A large increase in the amplitude of perturbations occurs when the friction
coefficient increases with temperature. This has to be taken into account when
constructing models of warm inflation. New results are also given for the
thermal fluctuations in the weak regime of warm inflation when the friction
coefficient is relatively small.Comment: 14 pages, 4 figures, ReVTe
Plasmodium falciparum Variant Surface Antigen Expression Patterns during Malaria
The variant surface antigens expressed on Plasmodium falciparum–infected erythrocytes are potentially important targets of immunity to malaria and are encoded, at least in part, by a family of var genes, about 60 of which are present within every parasite genome. Here we use semi-conserved regions within short var gene sequence “tags” to make direct comparisons of var gene expression in 12 clinical parasite isolates from Kenyan children. A total of 1,746 var clones were sequenced from genomic and cDNA and assigned to one of six sequence groups using specific sequence features. The results show the following. (1) The relative numbers of genomic clones falling in each of the sequence groups was similar between parasite isolates and corresponded well with the numbers of genes found in the genome of a single, fully sequenced parasite isolate. In contrast, the relative numbers of cDNA clones falling in each group varied considerably between isolates. (2) Expression of sequences belonging to a relatively conserved group was negatively associated with the repertoire of variant surface antigen antibodies carried by the infected child at the time of disease, whereas expression of sequences belonging to another group was associated with the parasite “rosetting” phenotype, a well established virulence determinant. Our results suggest that information on the state of the host–parasite relationship in vivo can be provided by measurements of the differential expression of different var groups, and need only be defined by short stretches of sequence data
Polar vortex evolution during Northern Hemispheric winter 2004/05
As a part of the project "Atmospheric Wave Influences upon the Winter Polar
Vortices (0–100 km)" of the CAWSES program, data from meteor and Medium
Frequency radars at 12 locations and MetO (UK Meteorological Office) global
assimilated fields have been analyzed for the first campaign during the
Northern Hemispheric winter of 2004/05. The stratospheric state has been
described using the conventional zonal mean parameters as well as
Q-diagnostic, which allows consideration of the longitudinal variability.
The stratosphere was cold during winter of 2004/05, and the polar vortex was
relatively strong during most of the winter with relatively weak
disturbances occurring at the end of December and the end of January. For
this winter the strongest deformation with the splitting of the polar vortex
in the lower stratosphere was observed at the end of February. Here the
results show strong latitudinal and longitudinal differences that are
evident in the stratospheric and mesospheric data sets at different
stations. Eastward winds are weaker and oscillations with planetary wave
periods have smaller amplitudes at more poleward stations. Accordingly, the
occurrence, time and magnitude of the observed reversal of the zonal
mesospheric winds associated with stratospheric disturbances depend on the
local stratospheric conditions. In general, compared to previous years, the
winter of 2004/05 could be characterized by weak planetary wave activity at
stratospheric and mesospheric heights
Approaching the motional ground state of a 10-kg object
The motion of a mechanical object— even a human-sized object— should be governed by the rules of quantum mechanics. Coaxing them into a quantum state is, however, difficult: the thermal environment effectively masks any quantum signature of the object’s motion. Indeed, it also masks effects of proposed modifications of quantum mechanics at large mass scales. We prepare the center-of-mass motion of a 10 kg mechanical oscillator in a state with an average phonon occupation of 10.8. The reduction in oscillator temperature, from room temperature to 77 nK, represents a 100-fold improvement in the reduction of temperature of a solid-state mechanical oscillator— commensurate with a 11 orders-of-magnitude suppression of quantum back-action by feedback — and a 10 orders-of-magnitude increase in the mass of an object prepared close to its motional ground state
Excess air in the noble gas groundwater paleothermometer: A new model based on diffusion in the gas phase
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95411/1/grl24964.pd
Evaluation of a workplace suicide prevention program in the Australian manufacturing industry : protocol for a cluster-randomised trial of MATES in manufacturing
Males are at higher risk of death by suicide than females in Australia, and among men, blue-collar males are at higher risk compared to other working males. In response, MATES in Construction developed a workplace suicide prevention program for the construction sector in 2007 that has been widely implemented in Australia. In the current project, this program is being adapted and trialled in the manufacturing sector. The common aims of MATES programs are to improve suicide prevention literacy, help-seeking intentions, and helping behaviours. The program will be evaluated using a cluster randomised-controlled trial design with waitlist controls across up to 12 manufacturing worksites in Australia. We hypothesise that after 8 months of the MATES in Manufacturing program, there will be significantly greater improvements in help-seeking intentions (primary outcome) compared to waitlist controls. The project is led by Deakin University in collaboration with the University of Melbourne, and in partnership with MATES in Construction and a joint labour-management Steering Group. Trial registration: The trial was registered retrospectively with the Australian New Zealand Clinical Trials Registry on 25 January 2022 (ACTRN12622000122752)
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