6,444 research outputs found
The second-phase development of the China JinPing underground Laboratory
During 2013-2015 an expansion of the China JinPing underground Laboratory
(CJPL) will be undertaken along a main branch of a bypass tunnel in the JinPing
tunnel complex. This second phase of CJPL will increase laboratory space to
approximately 96,000 m^3, which can be compared to the existing CJPL-I volume
of 4,000 m^3. One design configuration has eight additional hall spaces, each
over 60 m long and approximately 12 m in width, with overburdens of about 2.4
km of rock, oriented parallel to and away from the main water transport and
auto traffic tunnels. Concurrent with the excavation activities, planning is
underway for dark matter and other rare-event detectors, as well as for
geophysics/engineering and other coupled multi-disciplinary sensors. In the
town meeting on 8 September, 2013 at Asilomar, CA, associated with the 13th
International Conference on Topics in Astroparticle and Underground Physics
(TAUP), presentations and panel discussions addressed plans for one-ton
expansions of the current CJPL germanium detector array of the China Darkmatter
EXperiment (CDEX) collaboration and of the duel-phase xenon detector of the
Panda-X collaboration, as well as possible new detector initiatives for dark
matter studies, low-energy solar neutrino detection, neutrinoless double beta
searches, and geoneutrinos. JinPing was also discussed as a site for a
low-energy nuclear astrophysics accelerator. Geophysics/engineering
opportunities include acoustic and micro-seismic monitoring of rock bursts
during and after excavation, coupled-process in situ measurements, local,
regional, and global monitoring of seismically induced radon emission, and
electromagnetic signals.Comment: 9 pages, 3 figures. 13th International Conference on Topics in
Astroparticle and Underground Physics, TAUP 201
Mechanisms for the biodehalogenation of iodocompounds
The deiodination of [125I]-4-iodobiphenyl, [125I]-4-iodonitrobenzene and [125I]-4-iodoaniline was investigated. No deiodination was detected in rat thyroid homogenates. However, at least three biodeiodination mechanisms were indicated for substrates in rat liver subcellar fractions. Microsomal dehalogenation occurred to a minor extent with increased dehalogenation taking place in the cytosol fraction. The cytosol deiodination was extensive for 4-iodonitrobenzene and was mediated by glutathione. A second cytosol deiodination mechanism, not mediated by glutathione, was evident when 4-iodobiphenyl was the substrate. This soluble enzyme system could be enhanced by Arochlor 1254 or 4-iodobiphenyl pretreatment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22572/1/0000117.pd
Matter-wave interferometry in a double well on an atom chip
Matter-wave interference experiments enable us to study matter at its most
basic, quantum level and form the basis of high-precision sensors for
applications such as inertial and gravitational field sensing. Success in both
of these pursuits requires the development of atom-optical elements that can
manipulate matter waves at the same time as preserving their coherence and
phase. Here, we present an integrated interferometer based on a simple,
coherent matter-wave beam splitter constructed on an atom chip. Through the use
of radio-frequency-induced adiabatic double-well potentials, we demonstrate the
splitting of Bose-Einstein condensates into two clouds separated by distances
ranging from 3 to 80 microns, enabling access to both tunnelling and isolated
regimes. Moreover, by analysing the interference patterns formed by combining
two clouds of ultracold atoms originating from a single condensate, we measure
the deterministic phase evolution throughout the splitting process. We show
that we can control the relative phase between the two fully separated samples
and that our beam splitter is phase-preserving
Gene Expression Profiling of Bronchoalveolar Lavage Cells Preceding a Clinical Diagnosis of Chronic Lung Allograft Dysfunction.
BackgroundChronic Lung Allograft Dysfunction (CLAD) is the main limitation to long-term survival after lung transplantation. Although CLAD is usually not responsive to treatment, earlier identification may improve treatment prospects.MethodsIn a nested case control study, 1-year post transplant surveillance bronchoalveolar lavage (BAL) fluid samples were obtained from incipient CLAD (n = 9) and CLAD free (n = 8) lung transplant recipients. Incipient CLAD cases were diagnosed with CLAD within 2 years, while controls were free from CLAD for at least 4 years following bronchoscopy. Transcription profiles in the BAL cell pellets were assayed with the HG-U133 Plus 2.0 microarray (Affymetrix). Differential gene expression analysis, based on an absolute fold change (incipient CLAD vs no CLAD) >2.0 and an unadjusted p-value ≤0.05, generated a candidate list containing 55 differentially expressed probe sets (51 up-regulated, 4 down-regulated).ResultsThe cell pellets in incipient CLAD cases were skewed toward immune response pathways, dominated by genes related to recruitment, retention, activation and proliferation of cytotoxic lymphocytes (CD8+ T-cells and natural killer cells). Both hierarchical clustering and a supervised machine learning tool were able to correctly categorize most samples (82.3% and 94.1% respectively) into incipient CLAD and CLAD-free categories.ConclusionsThese findings suggest that a pathobiology, similar to AR, precedes a clinical diagnosis of CLAD. A larger prospective investigation of the BAL cell pellet transcriptome as a biomarker for CLAD risk stratification is warranted
Real time forecasting and automatic species classification of harmful algal blooms (HAB) for fisheries management
Chaos game representation for comparison of whole genomes
BACKGROUND: Chaos game representation of genome sequences has been used for visual representation of genome sequence patterns as well as alignment-free comparisons of sequences based on oligonucleotide frequencies. However the potential of this representation for making alignment-based comparisons of whole genome sequences has not been exploited. RESULTS: We present here a fast algorithm for identifying all local alignments between two long DNA sequences using the sequence information contained in CGR points. The local alignments can be depicted graphically in a dot-matrix plot or in text form, and the significant similarities and differences between the two sequences can be identified. We demonstrate the method through comparison of whole genomes of several microbial species. Given two closely related genomes we generate information on mismatches, insertions, deletions and shuffles that differentiate the two genomes. CONCLUSION: Addition of the possibility of large scale sequence alignment to the repertoire of alignment-free sequence analysis applications of chaos game representation, positions CGR as a powerful sequence analysis tool
Quantitative assessment of fecal contamination in multiple environmental sample types in urban communities in Dhaka, Bangladesh using SaniPath microbial approach.
Rapid urbanization has led to a growing sanitation crisis in urban areas of Bangladesh and potential exposure to fecal contamination in the urban environment due to inadequate sanitation and poor fecal sludge management. Limited data are available on environmental fecal contamination associated with different exposure pathways in urban Dhaka. We conducted a cross-sectional study to explore the magnitude of fecal contamination in the environment in low-income, high-income, and transient/floating neighborhoods in urban Dhaka. Ten samples were collected from each of 10 environmental compartments in 10 different neighborhoods (4 low-income, 4 high-income and 2 transient/floating neighborhoods). These 1,000 samples were analyzed with the IDEXX-Quanti-Tray technique to determine most-probable-number (MPN) of E. coli. Samples of open drains (6.91 log10 MPN/100 mL), surface water (5.28 log10 MPN/100 mL), floodwater (4.60 log10 MPN/100 mL), produce (3.19 log10 MPN/serving), soil (2.29 log10 MPN/gram), and street food (1.79 log10 MPN/gram) had the highest mean log10 E. coli contamination compared to other samples. The contamination concentrations did not differ between low-income and high-income neighborhoods for shared latrine swabs, open drains, municipal water, produce, and street foodsamples. E. coli contamination levels were significantly higher (p <0.05) in low-income neighborhoods compared to high-income for soil (0.91 log10 MPN/gram, 95% CI, 0.39, 1.43), bathing water (0.98 log10 MPN/100 mL, 95% CI, 0.41, 1.54), non-municipal water (0.64 log10 MPN/100 mL, 95% CI, 0.24, 1.04), surface water (1.92 log10 MPN/100 mL, 95% CI, 1.44, 2.40), and floodwater (0.48 log10 MPN/100 mL, 95% CI, 0.03, 0.92) samples. E. coli contamination were significantly higher (p<0.05) in low-income neighborhoods compared to transient/floating neighborhoods for drain water, bathing water, non-municipal water and surface water. Future studies should examine behavior that brings people into contact with the environment and assess the extent of exposure to fecal contamination in the environment through multiple pathways and associated risks
Stressor- and Corticotropin releasing Factor-induced Reinstatement and Active Stress-related Behavioral Responses are Augmented Following Long-access Cocaine Self-administration by Rats
Rationale Stressful events during periods of drug abstinence likely contribute to relapse in cocaine-dependent individuals. Excessive cocaine use may increase susceptibility to stressor-induced relapse through alterations in brain corticotropin-releasing factor (CRF) responsiveness.
Objectives This study examined stressor- and CRF-induced cocaine seeking and other stress-related behaviors in rats with different histories of cocaine self-administration (SA).
Materials and methods Rats self-administered cocaine under short-access (ShA; 2 h daily) or long-access (LgA; 6 h daily) conditions for 14 days or were provided access to saline and were tested for reinstatement by a stressor (electric footshock), cocaine or an icv injection of CRF and for behavioral responsiveness on the elevated plus maze, in a novel environment and in the light–dark box after a 14- to 17-day extinction/withdrawal period.
Results LgA rats showed escalating patterns of cocaine SA and were more susceptible to reinstatement by cocaine, EFS, or icv CRF than ShA rats. Overall, cocaine SA increased activity in the center field of a novel environment, on the open arms of the elevated plus maze, and in the light compartment of a light–dark box. In most cases, the effects of cocaine SA were dependent on the pattern/amount of cocaine intake with statistically significant differences from saline self-administering controls only observed in LgA rats.
Conclusions When examined after several weeks of extinction/ withdrawal, cocaine SA promotes a more active pattern of behavior during times of stress that is associated with a heightened susceptibility to stressor-induced cocaine-seeking behavior and may be the consequence of augmented CRF regulation of addiction-related neurocircuitry
Engineered 2D Ising interactions on a trapped-ion quantum simulator with hundreds of spins
The presence of long-range quantum spin correlations underlies a variety of
physical phenomena in condensed matter systems, potentially including
high-temperature superconductivity. However, many properties of exotic strongly
correlated spin systems (e.g., spin liquids) have proved difficult to study, in
part because calculations involving N-body entanglement become intractable for
as few as N~30 particles. Feynman divined that a quantum simulator - a
special-purpose "analog" processor built using quantum particles (qubits) -
would be inherently adept at such problems. In the context of quantum
magnetism, a number of experiments have demonstrated the feasibility of this
approach. However, simulations of quantum magnetism allowing controlled,
tunable interactions between spins localized on 2D and 3D lattices of more than
a few 10's of qubits have yet to be demonstrated, owing in part to the
technical challenge of realizing large-scale qubit arrays. Here we demonstrate
a variable-range Ising-type spin-spin interaction J_ij on a naturally occurring
2D triangular crystal lattice of hundreds of spin-1/2 particles (9Be+ ions
stored in a Penning trap), a computationally relevant scale more than an order
of magnitude larger than existing experiments. We show that a spin-dependent
optical dipole force can produce an antiferromagnetic interaction J_ij ~
1/d_ij^a, where a is tunable over 0<a<3; d_ij is the distance between spin
pairs. These power-laws correspond physically to infinite-range (a=0),
Coulomb-like (a=1), monopole-dipole (a=2) and dipole-dipole (a=3) couplings.
Experimentally, we demonstrate excellent agreement with theory for 0.05<a<1.4.
This demonstration coupled with the high spin-count, excellent quantum control
and low technical complexity of the Penning trap brings within reach simulation
of interesting and otherwise computationally intractable problems in quantum
magnetism.Comment: 10 pages, 10 figures; article plus Supplementary Material
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