cssi/SciSciGPT-SciSciNet huggingface dataset:
Where There Are (Few) Skilled Birth Attendants

Recent efforts to reduce maternal mortality in developing countries have focused primarily on two long-term aims: training and deploying skilled birth attendants and upgrading emergency obstetric care facilities. Given the future population-level benefits, strengthening of health systems makes excellent strategic sense but it does not address the immediate safe-delivery needs of the estimated 45 million women who are likely to deliver at home, without a skilled birth attendant. There are currently 28 countries from four major regions in which fewer than half of all births are attended by skilled birth attendants. Sixty-nine percent of maternal deaths in these four regions can be attributed to these 28 countries, despite the fact that these countries only constitute 34% of the total population in these regions. Trends documenting the change in the proportion of births accompanied by a skilled attendant in these 28 countries over the last 15-20 years offer no indication that adequate change is imminent. To rapidly reduce maternal mortality in regions where births in the home without skilled birth attendants are common, governments and community-based organizations could implement a cost-effective, complementary strategy involving health workers who are likely to be present when births in the home take place. Training community-based birth attendants in primary and secondary prevention technologies (e.g. misoprostol, family planning, measurement of blood loss, and postpartum care) will increase the chance that women in the lowest economic quintiles will also benefit from global safe motherhood efforts.
The Mechanism Initiating and Controlling Monozygotic Twinning in Humans Remains to be Elucidated

Nine-banded armadillos almost invariably give birth to litters of monozygotic quadruplets (assuming no prenatal losses). The mechanism for this is thought to be related to delayed implantation following ovum fertilization. 1‐3 As a consequence of this evolutionary adaptation, offspring are born in the early spring (most commonly in March or April), rather than face the risks of birth in the winter months. Prior to implantation, the fertilised egg develops into a blastocyst vesicle bathed with endometrial fluids within the uterine cavity. During this delay, two consecutive divisions of growth centres occur, yielding four foetuses. (The mulita armadillo normally produces eight or more offspring from a single ovum.) Similarly, zygotic development, delayed artificially by temperature reduction or oxygen deprivation, experimentally enhances the rate of monozygotic twinning in selected test animals. 4‐6 The actual timing of implantation at the molecular level now seems to be regulated by blastocyst differentiation leading to trophoblastic elaboration of specific proteases and the process of integrin switching, 7 as well as the activity of oncofoetal fibronectin. 8 Therefore, it has been proposed that monozygotic twinning results from developmental arrest occurring very early in embryonic life, before the onset of tissue differentiation. 9,10 This may be a consequence of delayed implantation related to infrequent expression of restrained genetic capability or to biochemical malfunction. Recent examination of the seasonal variation of twin births tends to support this proposal. The report in the March 1999 issue of Twin Research points to the increased incidence of human twin deliveries in March and April. 11 The length of gestation of twins is, within a couple of weeks, typically the same as singletons. As with other biological functions, the timing of successful fertilization (and hence delivery) especially in humans is the end result of the interaction of multiple factors including fecundity, diet, weather, economics, geography, and social issues. For example, a study of the seasonality of monozygotic twin birth rates in Great Britain was equivocal and inconclusive. 12 Natural monozygotic multifoetal pregnancies are quite different from polyzygotic in aetiology, frequency, risk, and dependent influences (such as race and heredity). So too, in elucidating the mechanism of monozygotic twinning, it is important carefully to distinguish test subjects by zygosity.
Isolation of Marine Polycyclic Aromatic Hydrocarbon (PAH)- Degrading Cycloclasticus Strains from the Gulf of Mexico and Comparison of Their PAH Degradation Ability with That of Puget Sound Cycloclasticus Strains

Phenanthrene- and naphthalene-degrading bacteria were isolated from four offshore and nearshore locations in the Gulf of Mexico by using a modified most-probable-number technique. The concentrations of these bacteria ranged from 102 to 106 cells per ml of wet surficial sediment in mildly contaminated and noncontaminated sediments. A total of 23 strains of polycyclic aromatic hydrocarbon (PAH)-degrading bacteria were obtained. Based on partial 16S ribosomal DNA sequences and phenotypic characteristics, these 23 strains are members of the genus Cycloclasticus. Three representatives were chosen for a complete phylogenetic analysis, which confirmed the close relationship of these isolates to type strain Cycloclasticus pugetii PS-1, which was isolated from Puget Sound. PAH substrate utilization tests which included high-molecular-weight PAHs revealed that these isolates had similar, broad substrate ranges which included naphthalene, substituted naphthalenes, phenanthrene, biphenyl, anthracene, acenaphthene, and fluorene. Degradation of pyrene and fluoranthene occurred only when the strains were incubated with phenanthrene. Two distinct partial PAH dioxygenase iron sulfur protein (ISP) gene sequences were PCR amplified from Puget Sound and Gulf of Mexico Cycloclasticus strains. Phylogenetic analyses of these sequences revealed that one ISP type is related to the bph type of ISP sequences, while the other ISP type is related to the nah type of ISP sequences. The predicted ISP amino acid sequences for the Gulf of Mexico and Puget Sound strains are identical, which supports the hypothesis that these geographically separated isolates are closely related phylogentically. Cycloclasticus species appear to be numerically important and widespread PAH-degrading bacteria in both Puget Sound and the Gulf of Mexico.
Diameter Constriction Reduces Intramural Circumferential Stress Gradient in the Vein Under Arterial Pressures

Coronary and peripheral artery diseases are a leading cause of morbidity and mortality in developed countries. For severe cases, surgical intervention to bypass the disease using autologous vessels continues to be the preferred choice of treatment. These bypass vessels are typically obtained from the venous vasculature. Despite the superior long-term patency of veins over synthetic grafts, one-year failure rates approach 30–40% in both the coronary and peripheral systems [1–2]. Still, bypass surgery remains the recommended therapy for most persons with severe arterial blockages [3]. As the number of bypass procedures increase and patients receiving bypasses live longer, improving the lifetime of bypass grafts is increasingly important.© 2012 ASME
Imaginability, Possibility, and the Puzzle of Imaginative Resistance

Introduction It is standard practice in philosophical inquiry to test a general thesis (of the form ‘F iff G’ or ‘F only if G’) by attempting to construct a counterexample to it. If we can imagine or conceive of an F that isn't a G, then we have evidence that there could be an F that isn't a G — and thus evidence against the thesis in question; if not, then the thesis is (at least temporarily) secure. Or so it is standardly claimed. But there is increasing skepticism about how seriously to take what we can imagine or conceive as evidence for (or against) a priori philosophical theses, given the many historical examples of now-questionable theses that once seemed impossible to doubt — and also the recent experimental research suggesting that our verdicts on Gettier cases, trolley cases, and the scenarios depicted in other familiar thought-experiments may be affected by cultural, situational, and other adventitious factors.
Terabus: Chip-to-chip board-level optical data buses

Optical interconnects using polymer waveguides on circuit boards have been demonstrated. Wirebond-free ultradense transceivers provide 160 Gb/s bidirectional throughput with 16 parallel waveguide-connected transmitters and receivers. Initial designs use 985 nm VCSELs. Migration to the industry-standard 850 nm VCSEL wavelength is underway, also providing lower waveguide loss.
The Flat-Ribbon Configuration of the Periplasmic Flagella of Borrelia burgdorferi and Its Relationship to Motility and Morphology

Electron cryotomography was used to analyze the structure of the Lyme disease spirochete, Borrelia burgdorferi. This methodology offers a new means for studying the native architecture of bacteria by eliminating the chemical fixing, dehydration, and staining steps of conventional electron microscopy. Using electron cryotomography, we noted that membrane blebs formed at the ends of the cells. These blebs may be precursors to vesicles that are released from cells grown in vivo and in vitro. We found that the periplasmic space of B. burgdorferi was quite narrow (16.0 nm) compared to those of Escherichia coli and Pseudomonas aeruginosa. However, in the vicinity of the periplasmic flagella, this space was considerably wider (42.3 nm). In contrast to previous results, the periplasmic flagella did not form a bundle but rather formed a tight-fitting ribbon that wraps around the protoplasmic cell cylinder in a right-handed sense. We show how the ribbon configuration of the assembled periplasmic flagella is more advantageous than a bundle for both swimming and forming the flat-wave morphology. Previous results indicate that B. burgdorferi motility is dependent on the rotation of the periplasmic flagella in generating backward-moving waves along the length of the cell. This swimming requires that the rotation of the flagella exerts force on the cell cylinder. Accordingly, a ribbon is more beneficial than a bundle, as this configuration allows each periplasmic flagellum to have direct contact with the cell cylinder in order to exert that force, and it minimizes interference between the rotating filaments.
The visuotopic organization of the superior colliculus of the owl monkey (Aotus trivirgatus) and the bush baby (Galago senegalensis)

Abstract Microelectrodes were used to map the representation of the visual field in the superior colliculus of the owl monkey and bush baby. The results lead to the conclusion that the representation in these primates is restricted to the contralateral half of the visual field in each tectum, while the representation reported for several other species of mammals is more extensive including part of the ipsilateral half field and all or most of the retina of the contralateral eye. Thus, we conclude that at least two different basic types of visuotopic organization are found in the mammalian superior colliculus.
Subterahertz attenuation in coplanar waveguides

In this paper, the attenuation of coplanar waveguides (CPWs) with wide and narrow ground planes have been simulated and compared with experimental results up to 1 THz. By assessing the validity of the full-wave analysis, the subterahertz attenuation of CPWs can be predicted. Furthermore, it is quantitatively verified that the use of narrow ground planes significantly reduces the radiation loss, which leads to a large reduction in the total attenuation of CPWs at subterahertz frequencies.
NASA launch schedule

The National Aeronautics and Space Administration (NASA) has a record-setting launch schedule for 1984—10 space shuttle flights (see Table 1), 10 satellite deployments from the space shuttle in orbit and 12 unmanned missions using expendable launch vehicles. Also scheduled is the launch on March 1 for the National Oceanic and Atmospheric Administration of Landsat D′, the nation's second earth resources satellite. The launch activity will begin February 3 with the launch of shuttle mission 41-B using the orbiter Challenger. Two communications satellites will be deployed from 41-B: Westar-VI, for Western Union, and Palapa B-2 for the government of Indonesia. The 8-day mission will feature the first shuttle landing at Kennedy Space Center in Florida; and the first flight of the Manned Maneuvering Unit, a self-contained, propulsive backpack that will allow astronauts to move about in space without being tethered to the spacecraft.
Twin Half-sibs: A Research Design for Genetic Epidemiology of Common Dental Disorders

Dental caries and the chronic type of periodontal disease are classic examples of common familial diseases that are complex and multifactorial in etiology. Due to previous methodological limitations, there is no information at present on the genetic and shared environmental risks within families that account for familial aggregation of these diseases. Such information, however, is needed in the long run to help specify modifiable family environments that affect the frequency and/or severity of the disease, and thereby to aid in the planning of prevention strategies to be targeted at the family level. Recently, an innovative genetic model has been described to test the genetic and environmental basis of chronic familial diseases in identical (monozygotic) twins, their spouses, and their offspring, who are genetically half-sibs. In this paper, the method is detailed and shown to be appropriate not only for partitioning shared genetic and environmental risks within families, but also for delineating maternal effects and assortative mating as two non-genetic mechanisms that may ultimately be found to affect the incidence of disease.
Structural insight into the protein translocation channel

A structurally conserved protein translocation channel is formed by the heterotrimeric Sec61 complex in eukaryotes, and SecY complex in archaea and bacteria. Electron microscopy studies suggest that the channel may function as an oligomeric assembly of Sec61 or SecY complexes. Remarkably, the recently determined X-ray structure of an archaeal SecY complex indicates that the pore is located at the center of a single molecule of the complex. This structure suggests how the pore opens perpendicular to the plane of the membrane to allow the passage of newly synthesized secretory proteins across the membrane and opens laterally to allow transmembrane segments of nascent membrane proteins to enter the lipid bilayer. The electron microscopy and X-ray results together suggest that only one copy of the SecY or Sec61 complex within an oligomer translocates a polypeptide chain at any given time.
Cristobalite Authigenic Origin in Relation to Montmorillonite and Quartz Origin in Bentonites

Three kinds of opal-cristobalite, differentiated by the sharpness of the 4·1 A XRD peak, were isolated from the Helms (Texas) bentonite by selective chemical dissolution followed by specific gravity separation. The δ18O value (oxygen isotope abundance) for these cristobalite isolates ranged from approximately 26–30‰ (parts per thousand), increasing with increased breadth of the 4·1 A XRD peak. Opal-cristobalite isolated from the Monterey diatomite had a δ18O value of 34‰. These δ18O values are in the range for Cretaceous cherts (approximately 32‰) and are unlike the values of 9–11‰ obtained for low-cristobalite (XRD peaks at 4·05, 3·13, 2·4, and 2·49) formed hydrothermally or isolated from the vesicles of obsidian. The morphology pseudomorphic after diatoms, observed with the scanning electron microscope, was more apparent in the opal-cristobalite from the Monterey diatomite of Miocene age (approximately 10 million yr old) than in the spongy textured opal-cristobalite from the Helms bentonite, reflecting the 40 million yr available for crystallization since Upper Eocene. The oxygen isotope abundance of Helms montmorillonite (δ18O = 26‰) indicates that it was formed in sea water while the δ18O values of the associated opal-cristobalite indicate that this SiO2 polymorph probably formed at approximately 25°C in meteoric water. Although both cristobalite and mont-montmorillonite in the bentonite were authigenic, the crystallization of the SiO2 phase apparently required a considerably longer period and occurred mainly after tectonic uplift. In contrast to the results for cristobalite, quartz from the Helms and Upton (Wyoming) bentonites had δ18O values of 15 and 21‰ respectively. Such intermediate values, similar to those of aerosolic dusts of the Northern Hemisphere, loess, and many fluvial sediments and shales of the North Central United States (U.S.A.), preclude either a completely authigenic or a completely igneous origin for the quartz. These values probably result from a mixing of quartz from high and low temperature sources, detritally added to the ash or bentonite bed.
Risk of toxicity in patients with elevated theophylline levels

Toxic side effects of elevated theophylline levels range from minor symptoms to life-threatening complications. We investigated the incidence of life-threatening events in patients with elevated levels in order to identify those at low risk for significant theophylline toxicity. Five hundred ten episodes of elevated levels were reviewed in 214 hospitalized patients. Four seizures occurred in patients with prior seizures, while two had new onset seizures with levels of 27 and 30 μg/mL. All eight episodes of ventricular tachycardia occurred in patients who had a history of arrhythmias or who were critically ill. Seven patients had new supraventricular arrhythmias with levels of 21 to 40 μg/mL. Life-threatening events may occur in critically ill patients or patients with past seizures or arrhythmias with mildly elevated levels, although the extent to which theophylline toxicity contributes to morbidity or mortality in these patients is unclear. Patients who are otherwise healthy are unlikely to have significant theophylline toxicity with levels less than 25 μg/mL.
Frequent Closed Itemset Mining Using Prefix Graphs with an Efficient Flow-Based Pruning Strategy

This paper presents PGMiner, a novel graph-based algorithm for mining frequent closed itemsets. Our approach consists of constructing a prefix graph structure and decomposing the database to variable length bit vectors, which are assigned to nodes of the graph. The main advantage of this representation is that the bit vectors at each node are relatively shorter than those produced by existing vertical mining methods. This facilitates fast frequency counting of itemsets via intersection operations. We also devise several inter- node and intra-node pruning strategies to substantially reduce the combinatorial search space. Unlike other existing approaches, we do not need to store in memory the entire set of closed itemsets that have been mined so far in order to check whether a candidate itemset is closed. This dramatically reduces the memory usage of our algorithm, especially for low support thresholds. Our experiments using synthetic and real-world data sets show that PGMiner outperforms existing mining algorithms by as much as an order of magnitude and is scalable to very large databases.
Alteration by flutamide of neutrophil response to stimulation: Implications for tissue injury

Abstract When activated, inflammatory cells such as polymorphonuclear leukocytes (PMNs) can damage isolated hepatocytes in vitro . These studies were performed to determine if flutamide activates PMNs. Flutamide (Eulexin) is an orally active, nonsteroidal antiandrogen that can cause liver injury associated with inflammation. Activation of PMNs was assessed from the production of superoxide anion and the release of myeloperoxidase in the presence or absence of flutamide and phorbol myristate acetate (PMA) or f-methionylleucyl phenylalanine (fmlp). In addition, hepatocytes were cocultured with PMNs stimulated with PMA or fmlp in the presence or absence of flutamide, and cytotoxicity to hepatocytes was evaluated from the release of alanine aminotransferase into the medium. Flutamide alone did not stimulate the generation of superoxide anion by PMNs but potentiated its production in response to PMA. At lower concentrations of flutamide (i.e. 25 μM), there was a tendency toward increased release of myeloperoxidase, whereas at higher concentrations (i.e. 75–100 μM) flutamide inhibited degranulation in response to fmlp. In coculture with hepatocytes, PMNs exposed to either flutamide, fmlp, or PMA alone caused a significant increase in release of alanine aminotransferase. Hepatocellular toxicity caused by PMNs incubated with flutamide and PMA was additive and was not affected by the addition of superoxide dismutase and catalase. Flutamide had no significant effect on fmlp-induced injury in cocultures. These data indicate that flutamide alters the activation of PMNs by subsequent stimuli in vitro . In addition, in the presence of flutamide, minor PMN-mediated injury to isolated hepatocytes was observed.
The Role of Quality-Tier Loyalty on Consumer Price Sensitivity for Frequently Purchased Products

Understanding the consumer’s choice of brands belonging to different quality-tiers (for example, national brands vs. private label brands) is important for academics and marketing managers. This pa...
Single-Crystal and Electronic Structure of a 1.3 nm Indium Phosphide Nanocluster.

Magic-sized nanoclusters have been implicated as mechanistically relevant intermediates in the synthesis of group III-V quantum dots. Herein we report the single-crystal X-ray diffraction structure of a carboxylate-ligated indium phosphide magic-sized nanocluster at 0.83 A resolution. The structure of this cluster, In37P20(O2CR)51, deviates from that of known crystal phases and possesses a non-stoichiometric, charged core composed of a series of fused 6-membered rings. The cluster is completely passivated by bidentate carboxylate ligands exhibiting predominantly bridging binding modes. The absorption spectrum of the cluster shows an asymmetric line shape that is broader than what would be expected from a homogeneous sample. A combination of computational and experimental evidence suggests that the spectral line width is a result of multiple, discrete electronic transitions that couple to vibrations of the nanocrystal lattice. The product of reaction of this nanocluster with 1 equiv of water has also been ...
Tell-tale tails: Decomposing response times for live internet services

Internet services use a wide range of software during request processing. One very slow software component can increase response time significantly. Or, many slightly slow components can conspire to increase response time. This paper 1) describes an approach to model the slowdown caused by each software component and 2) diagnoses root causes of tail response times in live services. Our approach uses Independent Component Analysis (ICA) to decompose the response time of independent, parallel requests into normalized software delays. Our approach models delays with less than 17% error for a wide range of software. It also captures the degree of data parallelism for each component, a measure of normalized energy footprint. We applied our approach to 33 services hosting real users, e.g., Google, Bing and Twitter. We observed that the services with slowest tail response times were affected by many components conspiring to slow down response time. We also found that energy footprint and tail response time were correlated.
Mathematical constraints on the use of transmission line models to investigate the preliminary breakdown stage of lightning flashes

The initial stage of in-cloud lightning development is characterized by a series of initial breakdown pulses (IBPs), observed as abrupt electric field changes at a remote sensor. Recent studies have attributed this process to the stepwise elongation of a negative lightning leader channel and used transmission line (TL) models to interpret the observed electromagnetic emission. In these models a current pulse is injected at the base of the channel, propagates along it, and the current parameters are adjusted to fit the measured IBPs. In this paper we explore the limitations of TL models by comparing four of its variants: the classic TL (with no attenuation) and three modified transmission line models that have different current attenuation characteristics, i.e., following linear, exponential, and Gaussian functions. For a compact channel (less than a few hundred meters long) all four models tend to produce similar electromagnetic signatures, and nearly identical waveforms can be obtained by simply varying the channel length. It is impossible to simultaneously identify, with confidence, both channel length and the speed of current wave propagation at the source by matching a far-field waveform. The field-to-current conversion factor for in-cloud sources is not a constant and can vary by as much as 2 orders of magnitude depending on channel length and current pulse risetime. This conclusion contrasts with the assumption used by the National Lightning Detection Network, that the field-to-current conversion can be performed by a multiplicative constant, as it is done for return strokes in cloud-to-ground lightning.
Metabolist Utopias and Their Global Influence: Three Paradigms of Urbanism

Despite the recent revival of interest in the work of Metabolism, Japan’s architectural avant-garde in the 1960s, the Metabolist discourse of the city and its impact on modern society has not been ...
Effect of transthoracic vagotomy on canine gastric electrical activity.

Transthoracic vagotomy was performed in 5 dogs to determine its effect on the pattern of canine gastric electrical activity during fasting, during insulin-induced hypoglycemia, and after gastric instillation of water or cottonseed oil. Before vagotomy, the regularly recurring pacesetter potential (PP) found in the gastric wall during fasting had a mean frequency of 5.4 cycles per min and a faster velocity in the antrum than in the corpus. Action potentials (AP) accompanied approximately one-fourth of the antral PP. Insulin- induced hypoglycemia speeded corporal propagation of PP and increased the incidence of antral AP. Gastric instillation of water decreased the frequency of PP, slowed its corporal propagation, and increased the incidence of antral AP. Gastric instillation of cottonseed oil slowed corporal propagation of PP and reduced the incidence of antral AP. Vagotomy temporarily disorganized the orderly gastric electrical pattern during fasting and permanently (3 months) slowed the propagation of PP in the corpus and the antrum. Vagotomy permanently abolished the response of gastric electrical activity to insulin-induced hypoglycemia. In contrast, it did not change the pattern of the response to the instillation of water but did greatly diminish or eliminate the inhibitory effect of oil instillation on corporal PP propagation and on the occurrence of antral action potentials.
INTERNET RESOURCES: Plagiarism and cyber-plagiarism: A guide to selected resources on the Web

Sites universitaires portant sur la definition du plagiat, l'ampleur du probleme et l'ethique. Ressources et logiciels de prevention et de detection du plagiat. Conferences et documents de reference. Recherche de plagiat sur Google. Sites encourageant le plagiat...
The Swell Season

The novel The Swell Season (Prima Sezona) written 1967–75, published in 1975 and translated into English in 1983, is a less ambitious work in the quasi-autobiographical cycle. Sandwiched between the monumental Miracle and The Engineer, it reads like a lighthearted intermezzo in the author’s major fiction. Structured on the narrative of Danny, it repeats and extends some of the familiar situations from Skvorecký’s earlier works, particularly The Cowards. Chronologically, the events of this work precede those of any of the other novels. They take place in the early 1940s, when Danny was a seventh-grader in the Kostelec high school, and the German occupation had not yet resulted in the serious disruption of the everyday life of Czech citizens. The Nazi presence is felt, but the atrocities have not yet reached the level at which people’s conduct would be permeated by incessant fear. Only in the final episode are the later horrors intimated, when the news reaches Kostelec that the father of one of Danny’s friends has been shot as a hostage. In all other episodes confrontation with German power is more fun than a threat.
Linear Models of Structured Populations

In the previous chapter, we first discussed the linear difference equation model P t +1 = λ P t , which results in exponential growth or decay. After criticizing this model for not being realistic enough, we looked at nonlinear models that could result in quite complicated dynamics. However, there is another way our models in the last chapter were simplistic – they treated all individuals in a population identically. In most populations, there are actually many subgroups whose vital behavior can be quite different. For instance, in humans, the death rate for infants is often higher than for older children. Also, children before the age of puberty contribute nothing to the birth rate. Even among adults, death rates are not constant, but tend to rise with advancing age. In nonhuman populations, the differences can be more extreme. Insects go through a number of distinct life stages, such as egg, larva, pupa, and adult. Death rates may vary greatly across these different stages, and only adults are capable of reproducing. Plants also may have various stages they pass through, such as dormant seed, seedling, nonflowering, and flowering. How can a mathematical model take into account the subgroup structure that we would expect to play a large role in determining the overall growth or decline of such populations?
Global Importance Sampling of Glossy Surfaces Using the Photon Map

Importance sampling reduces the variance of Monte Carlo integration by focusing effort on the directions that contribute the most energy to the result. In this paper we present a computationally efficient global importance-sampling strategy. Final gather rays are generated in proportion to the product of all three factors of the rendering equation integrand: surface reflectance, incident radiance, and the cosine term. By focusing effort on those directions that contribute the most energy to the result, the variance is greatly reduced. To be suitable for an interactive system, the computational cost of generating samples and their associated probabilities must be low. Our method requires neither that the surface reflectance function be invertible, nor that an expensive calculation be performed after ray selection to evaluate the p.d.f. Building on Henrik Jensen's work, we use a photon map to estimate incident radiance. In this paper, we also use the photon map to render the final image. We compare our method to previous methods and conclude that our technique exhibits competitive variance reduction while requiring one fiftieth of the computation.
Impact of the structure of subcutaneous tissue on ultrasonic clutter

Subcutaneous tissue is often associated with ultrasonic clutter and phase aberration. However, the complexities of subcutaneous tissue are often replaced by far simpler models in phase aberration, and are not well defined in the case of ultrasonic clutter. We employed a nonlinear, full-wave simulation method to compare the impact of subcutaneous tissue structure on ultrasonic clutter. Simplified models of male and female connective tissue networks were created, including networks with varying degrees of fascial layer density and angles relative to the transducer probe. The models were given the speed of sound, density, and attenuation appropriate for the associated fat and connective tissue. The amount of ultrasonic clutter depended on the density and angle of the fascial layers, although the two factors were not necessarily independent. Increases in the density and angle of the fascial layers increased the magnitude of clutter. Differences were observed between the female and subcutaneous tissue structures, yielding approximately 3 to 15 dB higher clutter magnitude in the male structure. The human abdominal models generated relatively high clutter magnitude, ranging from near 0dB just beneath the abdominal layer to approximately −33dB and −27 dB for the two models. In these realistic models of human abdominal tissue, the high density of fascial layers increased the number of multipath reflections contributing to the clutter, and generated high clutter magnitude.
H/sup infinity /-optimal control for singularly perturbed systems. II. Imperfect state measurements

The authors study H/sup infinity /-optimal control of singularly perturbed linear systems under general imperfect state measurements using infinite-horizon formulations. Using a differential game theoretic approach, they first show that, as the singular perturbation parameter in approaches zero, the optimal disturbance attenuation level for the full-order system under a quadratic performance index converges to the maximum of the optimal disturbance attenuation levels for the slow and fast subsystems under appropriate slow and fast quadratic cost functions. Then, they construct a controller based on the slow subsystem only, and obtain conditions under which it delivers a desired performance level even though the fast dynamics have been completely neglected. The ultimate performance level achieved by this slow controller can be uniformly improved by a composite controller that uses some feedback from the output of the fast subsystem. The authors construct one such controller, using a two-step sequential procedure, which uses static feedback from the fast output and dynamic feedback from an appropriate slow output, each obtained by solving appropriate in -independent lower-dimensional H/sup infinity /-optimal control problems. >
Efficient Semiparametric Inference Under Two-Phase Sampling, With Applications to Genetic Association Studies.

ABSTRACTIn modern epidemiological and clinical studies, the covariates of interest may involve genome sequencing, biomarker assay, or medical imaging and thus are prohibitively expensive to measure on a large number of subjects. A cost-effective solution is the two-phase design, under which the outcome and inexpensive covariates are observed for all subjects during the first phase and that information is used to select subjects for measurements of expensive covariates during the second phase. For example, subjects with extreme values of quantitative traits were selected for whole-exome sequencing in the National Heart, Lung, and Blood Institute (NHLBI) Exome Sequencing Project (ESP). Herein, we consider general two-phase designs, where the outcome can be continuous or discrete, and inexpensive covariates can be continuous and correlated with expensive covariates. We propose a semiparametric approach to regression analysis by approximating the conditional density functions of expensive covariates given ine...
Encoding, fast and slow: low-latency video processing using thousands of tiny threads

We describe ExCamera, a system that can edit, transform, and encode a video, including 4K and VR material, with low latency. The system makes two major contributions. First, we designed a framework to run general-purpose parallel computations on a commercial "cloud function" service. The system starts up thousands of threads in seconds and manages inter-thread communication. Second, we implemented a video encoder intended for fine-grained parallelism, using a functional-programming style that allows computation to be split into thousands of tiny tasks without harming compression efficiency. Our design reflects a key insight: the work of video encoding can be divided into fast and slow parts, with the "slow" work done in parallel, and only "fast" work done serially.
The Conscience Wars in Historical and Philosophical Perspective: The Clash between Religious Absolutes and Democratic Pluralism

Drawing on history and philosophy, this chapter highlights the differences between the new breed of “conscientious objection” and more traditional ones. From a philosophical perspective, the focus is on the difference between philosophical accounts of conscientious objection a generation ago by Rawls and Dworkin and the philosophical implications of its present iterations giving rise to the “conscience wars” in light of the contrast between liberalism and democratic pluralism. From the historical standpoint, on the other hand, the analysis concentrates on the place of conscience in Western Christianity and on its evolution toward the emergence of secularism coupled with the institutionalization of religious tolerance at the end of the religious civil wars in Europe. This culminated in the Enlightenment’s privileging of freedom of religion while disempowering religion from the public arena in the context of implanting liberal constitutionalism. Based on a critical examination of the current conscience wars and conscientious objection jurisprudence, the chapter concludes that the increased religious contestation of the neutrality of liberalism warrants turning to a pluralist perspective that places religious and non-religious ideologies on an equal footing. Consistent with the advocated shift to pluralism, repoliticized religion ought to lose its formerly acquired privilege when confronting conflicting fundamental constitutional rights.
Activity-based sensing fluorescent probes for iron in biological systems

Iron is an essential nutrient for life, and its capacity to cycle between different oxidation states is required for processes spanning oxygen transport and respiration to nucleotide synthesis and epigenetic regulation. However, this same redox ability also makes iron, if not regulated properly, a potentially dangerous toxin that can trigger oxidative stress and damage. New methods that enable monitoring of iron in living biological systems, particularly in labile Fe2+ forms, can help identify its contributions to physiology, aging, and disease. In this review, we summarize recent developments in activity-based sensing (ABS) probes for fluorescence Fe2+ detection.
The Cancer Mutation D83V Induces an α-Helix to β-Strand Conformation Switch in MEF2B

MEF2B is a major target of somatic mutations in non-Hodgkin lymphoma. Most of these mutations are non-synonymous substitutions of surface residues in the MADS-box/MEF2 domain. Among them, D83V is the most frequent mutation found in tumor cells. The link between this hotspot mutation and cancer is not well understood. Here we show that the D83V mutation induces a dramatic α-helix to β-strand switch in the MEF2 domain. Located in an α-helix region rich in β-branched residues, the D83V mutation not only removes the extensive helix stabilization interactions but also introduces an additional β-branched residue that further shifts the conformation equilibrium from α-helix to β-strand. Cross-database analyses of cancer mutations and chameleon sequences revealed a number of well-known cancer targets harboring β-strand favoring mutations in chameleon α-helices, suggesting a commonality of such conformational switch in certain cancers and a new factor to consider when stratifying the rapidly expanding cancer mutation data.
Why Is There a Ratchet Effect? Evidence from Civil War Income Taxes

The ratchet effect in public finance refers to the historical phenomena that the size of government increases during a crisis but does not return to its previous level when the crisis ends. The traditional explanation is that voters change their views on the appropriate size of government during the crisis. But change in taste is an explanation of last resort: it should not be accepted without examining alternatives. This paper looks Civil War taxes as an illuminating case of the ratchet effect. Both the observed political process and the resulting mix of taxes suggest that interest groups, not voters, led to the ratchet effect in this case. During the Civil War both tariffs and income taxes increased, but only the higher tariff stayed. This paper uses an analytical narrative to show that this was because the new interest groups only wanted the higher tariff and not the income tax.
A comparative study of spray keratinocytes and autologous meshed split-thickness skin graft in the treatment of acute burn injuries.

Background ReCell (Avita Medical, Northridge, CA) is an autologous cell harvesting (ACH) device that enables a thin split-thickness skin biopsy to be processed to produce a cell population that includes a mixed population of keratinocytes, melanocytes, Langerhans cells, and papillary dermal fibroblasts for immediate delivery via a spray applicator onto a prepared skin surface. Materials and methods In this Institutional Review Board-approved US Food and Drug Administration phase 2 study, the authors prospectively evaluated the treatment of partial-thickness burns in patients with two 320 cm2 areas, 1 area treated with the ACH device and the other with a meshed split-thickness skin graft (MSTSG) as a control. The authors compared the treatment areas for graft take, pigmentation, and color match to surrounding healthy tissue, scarring, and pain. Results In this preliminary study, 10 patients were treated with this protocol. Eight patients had 100% take to both treatment areas and 2 patients had significant non-take and graft loss attributable to underexcised wound beds and difficulty with the spray applicator. Pigmentation and color match ratings were identical at week 52 and the Modified Vancouver Scar Scale scores were comparable. One subject rated the autologous cell harvesting site as having a better appearance, while the remaining subjects rated their ACH and MSTSG sites' appearances as being comparable. In early follow-up visits, pain ratings were slightly elevated in the ACH group due to graft healing; however, in visits following week 2, pain ratings at the ACH and MSTSG sites were rated similarly by all patients. Conclusion This preliminary report describes an early experience with the ACH device and the treatment of partial-thickness burn injuries. In this 10-patient series, patients benefitted from having a decreased donor site size and comparable outcomes with MSTSG treatment. While this preliminary underpowered study has provided positive results, there is a learning curve with choosing the proper wound for treatment with the ACH device, as well as with using the device.
Shape-Based Object Discovery in Images

This paper presents an overview of our recent work on shape-based object discovery in images. The overview focuses on the following related problems: (i) discovery of all distinct 2D object categories frequently occurring in an unlabeled set of images; (ii) learning a model of the discovered categories; and (iii) recognition and localization of objects from the discovered categories in new images. The paper argues that using image contours as basic features, and thus directly grounding object discovery and recognition on shape, offers a number of advantages in solving (i)–(iii) over more commonly used point features. Since shape is directly encoded by layouts of image contours, similar contour layouts across the images are expected to belong rather to object occurrences, than the background. The contour layouts are captured by a graph over all pairs of matching contours from different images. The graph’s maximum a posteriori multicoloring assignment is taken to represent the shapes of discovered objects. Our empirical evaluation suggests that shape is more expressive and discriminative than photometric features for object discovery.
Design of a Sustainable Housing Complex in Haiti through Energy Modelling and Simulation Process

This paper presents the results of design research for the development of a sustainable housing complex in Haiti using the energy modeling and simulation processes. This study explores architectural and sustainable design strategies to design a prototype sustainable housing complex in a tropical climate that applies specifically to Haiti. In this research, the history, geography, and culture of Haiti are briefly analyzed in the context of family unit, community and economic aspects. The climate conditions are analyzed in the context of residents’ comfort, and the general guidelines are presented on how to design sustainable housing in tropical climate. The main research focus of this study is on the effectiveness of natural ventilation in the design of the Haitian housing complex. Due to the consideration of the poor economic situation of Haiti, especially after the massive earthquake in 2010, the design is focused on the passive strategies, not considering active mechanical cooling and heating systems. So, natural ventilation, as the main sustainable strategy of this study, is the key parameter to investigate using the EnergyPlus simulation program. Another following important parameter is the “adjusted comfort zone for Haitians.” The energy modeling and simulation technology is extensively used to make design decisions in this regard. The summary of this paper includes the proposed optimal design options and the adjusted comfort zone for Haitians. The effect of natural ventilation is also presented showing the improved indoor temperature and humidity levels of the proposed design compared to those of the conventional construction of Haiti.
Longevity and Epigenetics

In 2003, one of the most historic projects in modern medicine was completed, which laid out our genetic blueprint. The Human Genome Project resulted from the culmination of decades of work which includes the discovery of the double helix of deoxyribonucleic acid (DNA) and creation of laboratory tools for DNA mapping and sequencing. The human genome is made up of roughly 20,500 genes—far fewer than the initial estimates of 100,000 or more. These genes are comprised from nearly three billion A-T and G-C base pairs. A single-nucleotide mutation can equate to a nonsense mutation, leading to transcription of a premature stop codon and ultimately a nonfunctional protein. These nonfunctional proteins are known to cause disorders such as Duchenne’s muscular dystrophy (DMD), which results from an incomplete copy of the dystrophin gene being transcribed and then translated into a defective protein product which is vital to the muscle fiber cell membrane [1].
Geographic Variation in the Initiation of Commonly Used Opioids and Dosage Strength in United States Nursing Homes.

Objectives:To examine and quantify geographic variation in the initiation of commonly used opioids and prescribed dosage strength among older US nursing home residents.Methods:We merged 2011 Minimum Data Set 3.0 to Medicare claims and facility characteristics data to conduct a cross-sectional study
Whole-heart spiral simultaneous multi-slice first-pass myocardial perfusion imaging.

Purpose To develop and evaluate a simultaneous multislice (SMS) spiral perfusion pulse sequence with whole-heart coverage. Methods An orthogonal set of phase cycling angles following a Hadamard pattern was incorporated into a golden-angle (GA) variable density spiral perfusion sequence to perform SMS imaging at different multiband (MB) factors. Images were reconstructed using an SMS extension of L1-SPIRiT that we have termed SMS-L1-SPIRiT. The proposed sequence was evaluated in 40 subjects (10 each for MB factors of 1, 2, 3, and 4). Images were blindly graded by 2 cardiologists on a 5-point scale (5, excellent). To quantitatively evaluate the reconstruction performance against images acquired without SMS, the MB =1 data were used to retrospectively simulate data acquired at MB factors of 2 to 4. Results Analysis of the SMS point-spread function for the desired slice showed that the proposed sampling strategy significantly canceled the main-lobe energy of the other slices and has low side-lobe energy resulting in an incoherent temporal aliasing pattern when rotated by the GA. Retrospective experiments demonstrated the SMS-L1-SPIRiT method removed aliasing from the interfering slices and showed excellent agreement with the ground-truth MB =1 images. Clinical evaluation demonstrated high-quality perfusion images with average image-quality scores of 4.3 ± 0.5 (MB =2), 4.2 ± 0.5 (MB =3), and 4.4 ± 0.4 (MB =4) with no significant quality difference in image quality between MB factors (P = 0.38). Conclusion SMS spiral perfusion at MB factors 2, 3, and 4 produces high-quality perfusion images with whole-heart coverage in a clinical setting with high sampling efficiency.