7,336 research outputs found
Generation of Entanglement Outside of the Light Cone
The Feynman propagator has nonzero values outside of the forward light cone.
That does not allow messages to be transmitted faster than the speed of light,
but it is shown here that it does allow entanglement and mutual information to
be generated at space-like separated points. These effects can be interpreted
as being due to the propagation of virtual photons outside of the light cone or
as a transfer of pre-existing entanglement from the quantum vacuum. The
differences between these two interpretations are discussed.Comment: 25 pages, 7 figures. Additional references and figur
Interstellar: Using Halide's Scheduling Language to Analyze DNN Accelerators
We show that DNN accelerator micro-architectures and their program mappings
represent specific choices of loop order and hardware parallelism for computing
the seven nested loops of DNNs, which enables us to create a formal taxonomy of
all existing dense DNN accelerators. Surprisingly, the loop transformations
needed to create these hardware variants can be precisely and concisely
represented by Halide's scheduling language. By modifying the Halide compiler
to generate hardware, we create a system that can fairly compare these prior
accelerators. As long as proper loop blocking schemes are used, and the
hardware can support mapping replicated loops, many different hardware
dataflows yield similar energy efficiency with good performance. This is
because the loop blocking can ensure that most data references stay on-chip
with good locality and the processing units have high resource utilization. How
resources are allocated, especially in the memory system, has a large impact on
energy and performance. By optimizing hardware resource allocation while
keeping throughput constant, we achieve up to 4.2X energy improvement for
Convolutional Neural Networks (CNNs), 1.6X and 1.8X improvement for Long
Short-Term Memories (LSTMs) and multi-layer perceptrons (MLPs), respectively.Comment: Published as a conference paper at ASPLOS 202
Predictors of free sugars intake trajectories across early childhood â results from the SMILE birth cohort study
Foods and beverages high in free sugars can displace healthier choices and increase the risk of weight gain, dental caries, and noncommunicable diseases. Little is known about the intake of free sugars across early childhood. This study aimed to examine the longitudinal intake from 1 to 5 years of free sugars and identify the independent maternal and child-related predictors of intake in a cohort of Australian children participating in the Study of Mothersâ and Infantsâ Life Events Affecting Oral Health (SMILE). Free sugars intake (FSI) was previously estimated at 1, 2, and 5 years of age, and three distinct FSI trajectories were determined using group-based trajectory modelling analysis. This study utilized multinomial logistic regression to identify the maternal and child-related predictors of the trajectories. The risk of following the âhigh and increasingâ trajectory of FSI compared to the âlow and fast increasingâ trajectory was inversely associated with socio-economic disadvantage (aRRR 0.83; 95% CI 0.75â0.92; p < 0.001), lower for females (aRRR 0.56; 95% CI 0.32â0.98; p = 0.042), and higher in children with two or more older siblings at birth (aRRR 2.32; 95% CI 0.99â5.42; p = 0.052). Differences in trajectories of FSI were evident from an early age and a high trajectory of FSI was associated primarily with socio-economic disadvantage, providing another example of diet quality following a social gradient
Does special relativity theory tell us anything new about space and time?
It will be shown that, in comparison with the pre-relativistic
Galileo-invariant conceptions, special relativity tells us nothing new about
the geometry of spacetime. It simply calls something else "spacetime", and this
something else has different properties. All statements of special relativity
about those features of reality that correspond to the original meaning of the
terms "space" and "time" are identical with the corresponding traditional
pre-relativistic statements. It will be also argued that special relativity and
Lorentz theory are completely identical in both senses, as theories about
spacetime and as theories about the behavior of moving physical objects.Comment: 26 pages, LaTeX, new passages adde
Ultrasonic Nondestructive Evaluation Using Laser Transducers
A program is described which employs lasers for ultrasonic NDE. A high-power laser is used to generate a brief sound pulse in the test specimen. A second low-power laser then measures the response of the specimen to that sound pulse.
The response of the specimen is measured by a âLaser Vibrometer.â This is a novel type of heterodyne interferometer which focuses a Helium-Neon laser beam onto the surface of the specimen and measures its displacement. Displacements as small as 2Ă10-12 meters on a 0.15 sec averaging time can be detected and also displacements of 1.5Ăl0-9 meters on a 10-MHz bandwidth. The Laser Vibrometer has a well defined frequency response and does not introduce distortion.
The sound generating laser is either a pulsed carbon dioxide TEA laser or a YAG laser. The peak power exceeds 10 M watt. Two mechanisms for generating the sound are discussed. The thermoelastic mechanism relies on the thermal expansion of the surface, causing it to move. The reaction to this causes a pressure pulse in the specimen. Another mechanism allows a small amount of the surface to be ablated and the reaction to this causes a substantial pressure pulse in the specimen.
Both laser beams can be scanned over the surface of the specimen by a microprocessor controlled mirror. The microprocessor generates a raster scan of arbitrary size, number of lines, step size and speed.
Eventually this technique will allow the inspection of complex specimens without direct contact. This will eliminate the tedium and contact reliability problems associated with conventional piezo-ceramic NDE
Pairwise approach for analysis and reporting of childâs free sugars intake from a birth cohort study
Objectives:
The prospective cohort design is an important research design, but a common challenge is missing data. The purpose of this study is to compare three approaches to managing missing data, the pairwise (n = 1386 children), the partial or modified pairwise (n = 1019) and the listwise (n = 546), to characterize the trajectories of children's free sugars intake (FSI) across early childhood.
Methods:
By applying the Group-based Trajectory Model Technique to three waves of data collected from a prospective cohort study of South Australian children, this study examined the three approaches in managing missing data to validate and discuss children's FSI trajectories.
Results:
Each approach identified three distinct trajectories of child's FSI from 1 to 5âyears of age: (1) âlow and fast increasingâ, (2) âmoderate and increasingâ and (3) âhigh and increasingâ. The trajectory memberships were consistent across the three approaches, and were for the pairwise scenario (1) 15.1%, (2) 68.3% and (3) 16.6%; the partial or modified pairwise (1) 15.9%, (2) 64.1% and (3) 20.0%; and the listwise (1) 14.9%, (2) 64.9% and (3) 20.2% of children.
Conclusions:
Given the comparability of the findings across the analytical approaches and the samples' characteristics between baseline and across different data collection waves, it is recommended that the pairwise approach be used in future analyses to optimize the sample size and statistical power when examining the relationship between FSI in the first years of life and health outcome such as dental caries
Common Representation of Information Flows for Dynamic Coalitions
We propose a formal foundation for reasoning about access control policies
within a Dynamic Coalition, defining an abstraction over existing access
control models and providing mechanisms for translation of those models into
information-flow domain. The abstracted information-flow domain model, called a
Common Representation, can then be used for defining a way to control the
evolution of Dynamic Coalitions with respect to information flow
Increased use of malaria rapid diagnostic tests improves targeting of anti-malarial treatment in rural Tanzania: implications for nationwide rollout of malaria rapid diagnostic tests.
ABSTRACT: BACKGROUND: The World Health Organization recommends parasitological confirmation of all malaria cases. Tanzania is implementing a phased rollout of malaria rapid diagnostic tests (RDTs) for routine use in all levels of care as one strategy to increase parasitological confirmation of malaria diagnosis. This study was carried out to evaluated artemisinin combination therapy (ACT) prescribing patterns in febrile patients with and without uncomplicated malaria in one pre-RDT implementation and one post-RDT implementation area. METHODS: A cross-sectional health facility surveys was conducted during high and low malaria transmission seasons in 2010 in both areas. Clinical information and a reference blood film on all patients presenting for an initial illness consultation were collected. Malaria was defined as a history of fever in the past 48 hours and microscopically confirmed parasitaemia. Routine diagnostic testing was defined as RDT or microscopy ordered by the health worker and performed at the health facility as part of the health worker-patient consultation. Correct diagnostic testing was defined as febrile patient tested with RDT or microscopy. Over-testing was defined as a febrile patient tested with RDT or microscopy. Correct treatment was defined as patient with malaria prescribed ACT. Over-treatment was defined as patient without malaria prescribed ACT. RESULTS: A total of 1,247 febrile patients (627 from pre-implementation area and 620 from post-implementation area) were included in the analysis. In the post-RDT implementation area, 80.9% (95% CI, 68.2-89.3) of patients with malaria received recommended treatment with ACT compared to 70.3% (95% CI, 54.7-82.2) of patients in the pre-RDT implementation area. Correct treatment was significantly higher in the post-implementation area during high transmission season (85.9% (95%CI, 72.0-93.6) compared to 58.3% (95%CI, 39.4-75.1) in pre-implementation area (p=0.01). Over-treatment with ACT of patients without malaria was less common in the post-RDT implementation area (20.9%; 95% CI, 14.7-28.8) compared to the pre-RDT implementation area (45.8%; 95% CI, 37.2-54.6) (p<0.01) in high transmission. The odds of overtreatment was significantly lower in post- RDT area (adjusted Odds Ratio (OR: 95%CI) 0.57(0.36-0.89); and much higher with clinical diagnosis adjusted OR (95%CI) 2.24(1.37-3.67) CONCLUSION: Implementation of RDTs increased use of RDTs for parasitological confirmation and reduced over-treatment with ACT during high malaria transmission season in one area in Tanzania. Continued monitoring of the national RDT rollout will be needed to assess whether these changes in case management practices will be replicated in other areas and sustained over time. Additional measures (such as refresher trainings, closer supervisions, etc) may be needed to improve ACT targeting during low transmission seasons
Going to the exclusive show : exhibition strategies and moviegoing memories of Disneys animated feature films in Ghent (1937-1982)
This is a case study of the exploitation and experience of Disney's animated feature films from the 1930s to the 1980s in Ghent (Belgium). It is a historical study of programming practices and financial strategies which constructed childhood memories on watching Disney. The study is a contribution to a historical understanding of the implications of global distribution of film as cultural products and the counter pull of localism. Using a multi-method approach, the argument is made that the scarce screenings were strategically programmed to uplift the moviegoing experience into something out of the ordinary in everyday life. Programming and revenue data characterize the screenings as exclusive and generating high intakes. Consequently, the remembered screenings did not exhale an easy accessible social status nor an image of pervasiveness of popular childhood film, contradictory to conventional accounts of Disney's ubiquity in popular culture
Digestive Proteolytic Activity in the Sunn Pest, Eurygaster integriceps
The Sunn pest, Eurygaster integriceps Puton (Heteroptera: Scutelleridae), is one of the most important pests of wheat and causes considerable damage to this valuable crop annually. Digestive proteinase activity of adult insects was investigated using general and specific substrates and inhibitors. Proteolytic activity was low when the common conventional substrates, azoalbumin, azocasein and hemoglobin were used to assay salivary glands and midguts. Using the fluorescent casein substrate (BODIPY FL casein), total proteolytic activity was measured at different pH. Maximum proteolytic activity was detected at pH 7 (100%) and 8(65%) which suggested the presence of serine proteinases in the salivary glands. There was no detectable proteolytic activity in midgut extracts. The inhibitors; PMSF (inhibitor of serine proteinases) and TPCK (a specific chymotrypsin inhibitor) showed greater than 50% inhibitory effect on total proteolytic activity, however, TLCK (specific trypsin inhibitor) and E-64(specific cysteine proteinase inhibitor) did not inhibit total proteolytic activity. Using fluorescent specific substrates for serine and cysteine proteinases (Z-Arg-AMC, Z-Arg-Arg-AMC, Z-Arg-Phe-AMC and Suc-Ala-Ala-Pro-Phe-AMZ) revealed the presence of tryptic and chymotryptic activity in the salivary gland extract. Zymogram analysis under non-reducing SDS-PAGE conditions and using the substrate APNE showed at least 8 tryptic and chymotryptic activity bands in salivary gland extracts. A single high molecular weight band with tryptic activity (165 kDa) was detected using the substrate BApNA in a zymogram analysis uisng native-PAGE. Kinetic studies showed a km value of 0.6 mM for this enzyme against the substrate BApNA .The inhibitor TLCK decreased activity of the trypsin-like enzyme up to 73% and almost completely eliminated the only band related to this proteinase in the zymogram. Soybean Kunitz type trypsin inhibitor showed no effect on proteolytic activity of the trypsin-like serine proteinase. In general, the results revealed the presence of chymotrypsin- and trypsin-like serine proteinases in the salivary gland of E. integriceps, and it seems that the major total proteolytic activity is due to chymotrypsin proteinases
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