1,619 research outputs found
Balloon Experiments with the STL Flight Prototype Luminescent Chamber Final Technical Report
Performance of flight prototype luminescent chamber during high altitude balloon fligh
Resolving long-range spatial correlations in jammed colloidal systems using photon correlation imaging
We introduce a new dynamic light scattering method, termed photon correlation
imaging, which enables us to resolve the dynamics of soft matter in space and
time. We demonstrate photon correlation imaging by investigating the slow
dynamics of a quasi two-dimensional coarsening foam made of highly packed,
deformable bubbles and a rigid gel network formed by dilute, attractive
colloidal particles. We find the dynamics of both systems to be determined by
intermittent rearrangement events. For the foam, the rearrangements extend over
a few bubbles, but a small dynamical correlation is observed up to macroscopic
length scales. For the gel, dynamical correlations extend up to the system
size. These results indicate that dynamical correlations can be extremely
long-ranged in jammed systems and point to the key role of mechanical
properties in determining their nature.Comment: Published version (Phys. Rev. Lett. 102, 085702 (2009)) The Dynamical
Activity Mapsprovided as Supplementary Online Material are also available on
http://w3.lcvn.univ-montp2.fr/~lucacip/dam/movies.ht
Exploring the Microbiome of Healthy and Diseased Peri-Implant Sites Using Illumina Sequencing
Aim To compare the microbiome of healthy (H) and diseased (P) peri-implant sites and determine the core peri-implant microbiome. Materials and Methods Submucosal biofilms from 32 H and 35 P sites were analyzed using 16S rRNA sequencing (MiSeq, Illumina), QIIME and HOMINGS. Differences between groups were determined using Principal Coordinate Analysis (PCoA), t-tests and Wilcoxon rank sum test and FDR-adjusted. The peri-implant core microbiome was determined. Results PCoA showed partitioning between H and P at all taxonomic levels. Bacteroidetes, Spirochetes and Synergistetes were higher in P, while Actinobacteria prevailed in H (p\u3c0.05). Porphyromonas and Treponema were more abundant in P and while Rothia and Neisseria were higher in H (p\u3c0.05). The core peri-implant microbiome contained Fusobacterium, Parvimonas and Campylobacter sp. T. denticola and P. gingivalis levels were higher in P, as well as F. alocis, F fastidiosum and T. maltophilum (p\u3c0.05). Conclusion The peri-implantitis microbiome is commensal-depleted and pathogen-enriched, harboring traditional and new pathogens. The core peri-implant microbiome harbors taxa from genera often associated with periodontal inflammation
The Hydrogen Epoch of Reionization Array Dish I: Beam Pattern Measurements and Science Implications
The Hydrogen Epoch of Reionization Array (HERA) is a radio interferometer
aiming to detect the power spectrum of 21 cm fluctuations from neutral hydrogen
from the Epoch of Reionization (EOR). Drawing on lessons from the Murchison
Widefield Array (MWA) and the Precision Array for Probing the Epoch of
Reionization (PAPER), HERA is a hexagonal array of large (14 m diameter) dishes
with suspended dipole feeds. Not only does the dish determine overall
sensitivity, it affects the observed frequency structure of foregrounds in the
interferometer. This is the first of a series of four papers characterizing the
frequency and angular response of the dish with simulations and measurements.
We focus in this paper on the angular response (i.e., power pattern), which
sets the relative weighting between sky regions of high and low delay, and
thus, apparent source frequency structure. We measure the angular response at
137 MHz using the ORBCOMM beam mapping system of Neben et al. We measure a
collecting area of 93 m^2 in the optimal dish/feed configuration, implying
HERA-320 should detect the EOR power spectrum at z~9 with a signal-to-noise
ratio of 12.7 using a foreground avoidance approach with a single season of
observations, and 74.3 using a foreground subtraction approach. Lastly we study
the impact of these beam measurements on the distribution of foregrounds in
Fourier space.Comment: 13 pages, 9 figures. Replaced to match accepted ApJ versio
Bioinformatic Characterization of Genes and Proteins Involved in Blood Clotting in Lampreys
Lampreys and hagfish are the earliest diverging of extant vertebrates and are obvious targets for investigating the origins of complex biochemical systems found in mammals. Currently, the simplest approach for such inquiries is to search for the presence of relevant genes in whole genome sequence (WGS) assemblies. Unhappily, in the past a high-quality complete genome sequence has not been available for either lampreys or hagfish, precluding the possibility of proving gene absence. Recently, improved but still incomplete genome assemblies for two species of lamprey have been posted, and, taken together with an extensive collection of short sequences in the NCBI trace archive, they have made it possible to make reliable counts for specific gene families. Particularly, a multi-source tactic has been used to study the lamprey blood clotting system with regard to the presence and absence of genes known to occur in higher vertebrates. As was suggested in earlier studies, lampreys lack genes for coagulation factors VIII and IX, both of which are critical for the "intrinsic" clotting system and responsible for hemophilia in humans. On the other hand, they have three each of genes for factors VII and X, participants in the "extrinsic" clotting system. The strategy of using raw trace sequence "reads" together with partial WGS assemblies for lampreys can be used in studies on the early evolution of other biochemical systems in vertebrates
Statistical Mechanics of Glass Formation in Molecular Liquids with OTP as an Example
We extend our statistical mechanical theory of the glass transition from
examples consisting of point particles to molecular liquids with internal
degrees of freedom. As before, the fundamental assertion is that super-cooled
liquids are ergodic, although becoming very viscous at lower temperatures, and
are therefore describable in principle by statistical mechanics. The theory is
based on analyzing the local neighborhoods of each molecule, and a statistical
mechanical weight is assigned to every possible local organization. This
results in an approximate theory that is in very good agreement with
simulations regarding both thermodynamical and dynamical properties
Investigating the cost-effectiveness of videotelephone based support for newly diagnosed paediatric oncology patients and their families: design of a randomised controlled trial
BACKGROUND: Providing ongoing family centred support is an integral part of childhood cancer care. For families living in regional and remote areas, opportunities to receive specialist support are limited by the availability of health care professionals and accessibility, which is often reduced due to distance, time, cost and transport. The primary aim of this work is to investigate the cost-effectiveness of videotelephony to support regional and remote families returning home for the first time with a child newly diagnosed with cancer METHODS/DESIGN: We will recruit 162 paediatric oncology patients and their families to a single centre randomised controlled trial. Patients from regional and remote areas, classified by Accessibility/Remoteness Index of Australia (ARIA+) greater than 0.2, will be randomised to a videotelephone support intervention or a usual support control group. Metropolitan families (ARIA+ †0.2) will be recruited as an additional usual support control group. Families allocated to the videotelephone support intervention will have access to usual support plus education, communication, counselling and monitoring with specialist multidisciplinary team members via a videotelephone service for a 12-week period following first discharge home. Families in the usual support control group will receive standard care i.e., specialist multidisciplinary team members provide support either face-to-face during inpatient stays, outpatient clinic visits or home visits, or via telephone for families who live far away from the hospital. The primary outcome measure is parental health related quality of life as measured using the Medical Outcome Survey (MOS) Short Form SF-12 measured at baseline, 4 weeks, 8 weeks and 12 weeks. The secondary outcome measures are: parental informational and emotional support; parental perceived stress, parent reported patient quality of life and parent reported sibling quality of life, parental satisfaction with care, cost of providing improved support, health care utilisation and financial burden for families. DISCUSSION: This investigation will establish the feasibility, acceptability and cost-effectiveness of using videotelephony to improve the clinical and psychosocial support provided to regional and remote paediatric oncology patients and their families
Viewpoint: Estimating the causal effects of policies and programs
Estimation, inference and interpretation of the causal effects of programs and policies have all advanced dramatically over the past 25 years. We highlight three particularly important intellectual trends: an improved appreciation of the substantive importance of heterogeneous responses and of their methodological implications, a stronger focus on internal validity brought about by the âcredibility revolution,â and the scientific value that follows from grounding estimation and interpretation in economic theory. We discuss a menu of commonly employed partial equilibrium approaches to the identification of causal effects, emphasizing that the researcherâs central intellectual contribution always consists of making an explicit case for a specific causal interpretation given the relevant economic theory, the data, the institutional context and the economic question of interest. We also touch on the importance of general equilibrium effects and full costâbenefit analyses.RĂ©sumĂ©Point de vue: Sur lâestimation des effets causatifs des politiques et programmes. Dans le monde de lâestimation, lâinfĂ©rence et lâinterprĂ©tation des effets causatifs des programmes et des politiques, il y a eu des progrĂšs dramatiques au cours des derniers 25 ans. Les auteurs soulignent trois tendances intellectuelles particuliĂšrement importantes : une apprĂ©ciation amĂ©liorĂ©e de lâimportance substantielle des rĂ©ponses hĂ©tĂ©rogĂšnes et de leur importance mĂ©thodologique, une focalisation plus robuste sur la validitĂ© interne engendrĂ©e par la « rĂ©volution de la crĂ©dibilitĂ© », et la valeur scientifique qui dĂ©coule dâun ancrage de lâestimation et de lâinterprĂ©tation dans la thĂ©orie Ă©conomique. On discute un Ă©ventail dâapproches dâĂ©quilibre partiel Ă lâidentification des effets causatifs, mettant au premier plan que la contribution intellectuelle centrale du chercheur consiste Ă bĂątir un argumentaire explicite pour une interprĂ©tation causale spĂ©cifique compte tenu de la thĂ©orie Ă©conomique pertinente, des donnĂ©es, du contexte institutionnel, et de la question Ă©conomique dâintĂ©rĂȘt. On mentionne aussi lâimportance des effets dâĂ©quilibre gĂ©nĂ©ral et des analyses de tous les coĂ»ts et avantages.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134884/1/caje12217.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134884/2/caje12217_am.pd
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