cssi/SciSciGPT-SciSciNet huggingface dataset:
Optimal Distributed Submodular Optimization via Sketching

We present distributed algorithms for several classes of submodular optimization problems such as k-cover, set cover, facility location, and probabilistic coverage. The new algorithms enjoy almost optimal space complexity, optimal approximation guarantees, optimal communication complexity (and run in only four rounds of computation), addressing major shortcomings of prior work. We first present a distributed algorithm for k-cover using only O(n) space per machine, and then extend it to several submodular optimization problems, improving previous results for all the above problems-e.g., our algorithm for facility location problem improves the space of the best-known algorithm (Lindgren et al.). Our algorithms are implementable in various distributed frameworks such as MapReduce and RAM models. On the hardness side, we demonstrate the limitations of uniform sampling via an information theoretic argument. Furthermore, we perform an extensive empirical study of our algorithms (implemented in MapReduce) on a variety of datasets. We observe that using sketches 30-600 times smaller than the input, one can solve the coverage maximization problem with quality very close to that of the state-of-the-art single machine algorithm. Finally, we demonstrate an application of our algorithm in large-scale feature selection
PRODUCTIVITY AND NUTRIENT EXPORT STUDIES IN A CYPRESS SWAMP AND LAKE SYSTEM IN LOUISIANA

ABSTRACT During a 14-month period in 1973-74, several functional properties were studied in a swamp forest and lake system in Louisiana. The study area forms the upper drainage basin of the Barataria Bay estuary. Properties measured were: a) productivity of the two swamp forest components, bottomland hardwood (BLH) and baldcypress-tupelo (CT); b) productivity of lake and bayou waters; c) hydrology; and d) carbon and nutrient export to the lower estuary. Productivity of the BLH site was 800 g dry wt·m–2·yr–1 for stem biomass increase, 584 for litterfall, and 200 for understory production. Similar figures for CT were 500, 620, and 20. Total above-ground net productivity was 1584 for BLH and 1140 for CT. Net daytime photosynthesis (NDP) for the lake was 1418 g 02·m–2·yr–1 and nighttime respiration (NR) was 1868 (P/R = 0.76). For the bayous NDP was 316 and NR was 446 (P/R = 0.71). Water discharge from the basin is significant year-round except during the summer when evaporation equals precipitation. Annual export to the lower estuary (calculated from water discharge and materials concentrations) was 8016 metric tons of organic C, 1047 metric tons N, and 154 metric tons P. The greater part of this export occurred during the spring, corresponding to the spring peak in biological activity in the estuary.
Dielectric properties of Pb(Mg1/3Nb2/3)O3-PbTiO3/polyurethane 0-3 composites

In recent years, lead-based relaxor materials have been much researched for diverse applications. These include devices such as ferroelectric random access memory (FeRAM) [1], multilayer ceramic capacitor (MLCC) [2], ultrasonic transducer [3], and display devices [4] due to their high dielectric constant [5]. Composite piezoelectric materials are an especially useful choice for transducers such as medical ultrasound devices. These composites show voltage charge constant g33values that lead to the increased sensitivity. Moreover, the matching efficiency of acoustic impedance also improves due to the low density and the low velocity of composite material [6]. This paper considers the dielectric properties of Pb(Mg1/3Nb2/3)O3PbTiO3/polyurethane 0–3 composites not yet reported, showing the dependence of those properties. A 0–3 connectivity, a three dimensionally connected polymer matrix filled with discrete loaded piezoelectric ceramic particles, was considered. Historically, various connectivity patterns of PZT (lead zirconate titanate)-polymer composites have been studied to improve the piezoelectric properties of PZT ceramics [7, 8]. J. T. Wang et al. reports the composites have been studied using rigid epoxy with Pb(Mg1/3Nb2/3)O3PbTiO3 (PMN-PT) [9]. In contrast, J. Su et al. [10] states that polyurethane rubber produces 0.85% strain when an electric field of 7 MV/m is applied to a 0.1 mm thick sample. Moreover, a polyurethane composite, rather than epoxy composite, decreases stress inside the piezoelectric materials [11]. Therefore, piezoelectric composites with 0–3 connectivity were fabricated from PMN-PT powders and polyurethane rubber. These composites were investigated for dielectric properties with variations in active particle and PMN-PT/polyurethane interfacing. For the study, PMN-PT calcined powders were used as PMN-38 purchased from TRS Ceramics, Inc., PA, USA. The powders were pressed to form a disk of 25 mm × 1 mm under 100 MPa pressure. Following binder burn out at 500 ◦C, the pellets were then sintered at 1100 ◦C and 1150 ◦C for 2 h with the heating rate 50 ◦C/h and natural cooling in the furnace. Excess PbO (10 wt%) and PbZrO3 were added as PMN-PT source powders. The pellets were put on the platinum foil in a closed alumina crucible, and an oxygen atmosphere was employed for sintering. The sintered disks were crushed to powder with a mortar and pestle. The prepared powders were obtained by first sieving with
Intraspecific Variation and Information Content of Drumming in Three Plecoptera Species

Drumming is known in 104 species of Arctoperlaria (Insecta: Plecoptera) and is more advanced in the group Systellognatha. A clear definition of species-specificity, and critical information content conveyed during drumming, requires resolution of intraspecific variation. Our experimental studies of species representing ancestral and derived drumming patterns, particularly Pteronarcella badia (Hagen) Perlinella drymo (Newman), Taeniopteryx burksi (Ricker and Ross), Kogotus modestus (Banks) and Calineuria californica (Banks), indicate that females respond to male calls having: (1) a critical minimum threshold of beat number or specific rub number, (2) discriminate windows of beat intervals, and (3) other specific parameters such as bibeats. Biological variation was determined from response levels of five females to computer synthesized male calls representing a variation gradient around the typical expression of call parameters. T. burksi females answered at substantial levels only in the 90–130 msec beat interval range. K. modestus females responded at high levels only in a 38–55 msec intrabibeat interval range, but interbibeat intervals were unimportant at ± 33.3% of typical. C. californica females answered male rubs in the 340–553 Hz range at significantly higher levels than those in the 200–340 and 553–635 Hz range.
Investigating undergraduate health sciences students’ acceptance of evolution using MATE and GAENE

Despite the overwhelming agreement among scientists regarding the fundamental importance of evolution to all areas of biology, a lack of evolution understanding and acceptance has been reported in studies of students, educators, and members of society. In the present study, we investigate and report evolution acceptance in a population of undergraduate health sciences students enrolled in a first-year foundational biology course. Two published instruments—The Measure of Acceptance of the Theory of Evolution (MATE) and the Generalized Acceptance of Evolution Evaluation (GAENE)—were used to quantify evolution acceptance. A confirmatory factor analysis (CFA) was performed on both instruments to test whether the items measured the underlying construct sufficiently. Additionally, Rasch scaling was used to investigate fit between the data and the measurement model, and to determine if the MATE should be treated as a unidimensional or bidimensional instrument. Using correlation and regression analysis, we examined the relationships between the two measures of evolution acceptance, and between measures of evolution acceptance with other student variables of interest. The health sciences students in this study demonstrated high acceptance of evolution at the start of term, as well as a significant increase in evolution acceptance from pre- to post-test. CFA and Rasch scaling provided some evidence that the MATE is a bidimensional instrument, but considering MATE as a bidimensional instrument provided little additional insight compared to treating MATE as a unidimensional instrument. Measures of evolution acceptance resulting from the MATE and GAENE instruments were significantly and strongly correlated. Multiple regression modeling identified underrepresented minority status as a demographic variable predictive of evolution acceptance, and provided further evidence of the strong association between the MATE and GAENE instruments. The undergraduate health sciences students in this study demonstrated a significant increase in evolution acceptance from pre- to post-test after one semester of instruction in general biology. Measures of evolution acceptance from the MATE and GAENE instruments were strongly correlated whether MATE was treated as a unidimensional or bidimensional instrument. This work provides initial indications that the MATE and GAENE instruments perform comparably as measures of evolution acceptance. Although the instruments are closely related, this work found more psychometric evidence for interpreting and using GAENE scores than MATE scores as a measure of evolution acceptance.
Doppler Velocity Log Placement Effects on Autonomous Underwater Vehicle Navigation Accuracy

Doppler Velocity Logs (DVLs) provide an important correcting measurement to the Inertial Navigation Systems (INSs) of Autonomous Underwater Vehicles (AUVs). DVLs are typically co-located near the Inertial Measurement Unit (IMU) at the AUV’s center of buoyancy (CB) to permit a direct correction of the AUV’s linear velocities. However, recent research has demonstrated that mounting the DVL at a lever-arm offset from the CB changes the observability of vehicle states. This paper expands on previous research to explore the effects of DVL placement on AUV navigation accuracy in both loosely- and tightly-coupled frameworks. This paper finds that, in stark contrast to their standard placement, almost all practical AUVs could benefit from the DVL being mounted far from the CB to minimize navigation errors when integrated into a tightly-coupled framework. These results suggest that the DVL’s mounting location should be considered during the design stages of an AUV due to its effect on navigation accuracy.
Internal Model Based Smooth Transition of a Three-Phase Inverter Between Islanded and Grid-Connected Modes

Recent technical advances in control, protection and interconnection of distributed power generation units imply that it is practically viable and economically profitable to keep them as backup generators in isolated operating modes. Therefore, along with the development of islanding detection techniques, seamless operation in transition between islanded and grid connected modes is required and more sophisticated control strategies are needed to recognize the existing working condition and adjust the performance to meet the strict standards of grid interconnection. This paper presents a new adaptive control structure, based on internal model control (IMC), which uses multiple models and an inherent islanding detection method through an optimized switching mechanism to tune the operation of a three-phase inverter under transitions between islanded and grid-tied conditions. By applying a power synchronization method, the system emulates the operation of a synchronous machine which is needless to rely on a phase-locked loop to synchronize during the transitions. Hardware co-simulation environment in Simulink/PLECS and Xilinx System Generator have been utilized to evaluate the transient behavior of the controller in discretized domain and verify its robustness during parameter variations and load switching conditions. Various switching rules have been applied and a comparison of their effect in transient response is demonstrated. The results, taken from several case studies, confirm the significant robustness of the proposed control methodology.
Is brain iron trafficking part of the physiology of the amyloid precursor protein

The amyloid precursor protein is so named, because a proteolytic fragment of it was found associated with a neuropathic disorder now known as Alzheimer’s disease. This fragment, Aβ, along with tau makes up the plaques and tangles that are the hallmark of AD. Iron (and other first-row transition metals) is found associated with these proteinaceous deposits. Much research has focused on the relationship of the plaques and iron to the etiology of the disease. This commentary asks another question, one only more recently addressed namely, what is the physiologic function of the amyloid precursor protein (APP) and of its secretase-generated soluble species? Overall, the data make clear that APP and its products have neurotrophic functions and some data indicate one of these may be to modulate the trafficking of iron in the brain.
Renal denervation for hypertension: we've come a long way!

Renal sympathetic denervation (RSD), a therapeutic intervention for patients with hypertension (HTN), is undergoing active investigation. Prospective cohort studies and first-generation randomized controlled studies established the safety of RSD but its impact on blood pressure was variable (1-3).
Leptomeningeal spread with spinal involvement of pineal glioblastoma at initial presentation: A case report

Abstract A 51-year-old man presented with one week of acute headache, nausea, and vomiting. Brain and spine MRI showed an enhancing pineal lesion and intradural and leptomeningeal spread throughout the neuroaxis. An intradural biopsy was performed at L4–L5, and histopathology exhibited a malignant neuroepithelial tumor; molecular analysis confirmed gliobastoma WHO grade IV. The patient received craniospinal radiation and stereotactic boost to the large symptomatic pineal and spinal masses. Differential diagnosis for spinal involvement and leptomeningeal spread of pineal region tumors is wide, but we should include glioblastoma on this differential.
Opportunities and Advances in Radiomics and Radiogenomics in Neuro-Oncology

Neuro-oncology broadly encompasses life threatening malignancies of the brain and spinal cord including both primary as well as lesions metastasizing to the central nervous system. The biggest clinical challenge in the field currently is to be able to design personalized treatment management solutions in patients based on apriori knowledge of their survival outcome or response to conventional or experimental treatments. Radiomics or the quantitative extraction of subvisual data from conventional radiographic imaging and radiogenomics, statistically correlating radiomic features with point-mutations and next generation sequencing data, have recently emerged as unique mechanisms to offer insights into answering some of these clinically relevant questions related to diagnosis, classification, prognosis as well as assessing treatment response. In this review, we provide an overview of the framework for radiomic and radiogenomic approaches in neuro-oncology, including a brief description of the techniques commonly employed. Further, we will provide a review of some of the existing applications of radiomics and radiogenomics in neuro-oncology for tumor classification, survival prognosis, predicting response to therapies, as well as distinguishing benign post-treatment changes from tumor recurrence, using routine MRI scans. While highly promising, the clinical acceptance of radiomics and radiogenomics techniques will largely hinge on their resilience to non-standardization across imaging protocols, as well as in their ability to demonstrate reproducibility across large multi-institutional cohorts.
Children and Adolescents in Conflict and Displacement

Today, one in six young people lives in a conflict zone. Children and adolescents may experience armed conflict as witnesses and targets, participants and protestors, and victims and survivors. Young people also make up about half of the world’s refugees and internally displaced persons. Through conflict and displacement, these girls and boys encounter a tremendous array of risks to their survival and well-being while also contributing to the resilience of their families and communities. This chapter draws on the social ecological framework to conceptualize how children’s and adolescents’ social environments shape their experiences of, and responses to, armed conflict and forced migration. It also explores how factors at the community, family, interpersonal, and individual levels contribute to distress and resilience. The chapter highlights the vulnerability of subpopulations, such as unaccompanied and separated minors, young people associated with armed forces and groups, and young people in conflict with the law. The chapter concludes with a reflection on the need for holistic interventions designed to respond to this complex interplay of risk, protective, and promotive factors.
Black Box Coupled Mode Theory: Analysis of Loading Effects in Optical interactions between Nanoresonators

Black Box Coupled Mode Theory is an electromagnetic resonator analysis and design tool based on the theory of quasinormal modes. Alongside its rigorous formulation, the theory casts a novel insight into electromagnetic resonators' operation principles.
Sleep disorders and risk of traffic crashes: A naturalistic driving study analysis

Abstract Sleep disorders and various acute and chronic medical conditions affect the quality and quantity of an individual’s sleep causing excessive day time sleepiness. This study examined the relationship between clinical sleep disorders (i.e., shift work sleep disorder (SWSD), sleep apnea and insomnia) and crashes using naturalistic driving study data. Using data from 1892 events that occurred in six different US states, random effect binary logistic regression models were developed to estimate crash risk associated with SWSD, sleep apnea and insomnia. The study found that sleep disorders elevate crash risk in drivers. Drivers with SWSD exhibited the highest crash risk (OR = 2.96). Older drivers with SWSD were found to be more vulnerable and prone to crashes than other drivers. The analysis showed that drivers with sleep apnea and insomnia were 29% and 33% more likely, respectively, to be involved in a crash or a near-crash. For drivers with insomnia, factors such as age and sleep quality can elevate the associated crash risk. Decrease in sleep quality increases the likelihood of crash or near crash. The study also found that individuals with a sleep disorder are 29% more likely to be inattentive while driving as compared to drivers without a sleep disorder. The OR values found in this study were lower than those reported in studies using self-reported data and driver simulator experiments. In addition to medical diagnosis and treatment, transportation agencies could also consider alleviation strategies such as providing sufficient rest areas on highways and using technology such as in-vehicle and personal technologies that monitor drowsy in-vehicle behavior to increase driver attention. The use of transportation modes such as taxi, transportation network companies (e.g. Uber), or public transit, can be an alternative for shift workers returning home after completing their shift.
An Examination of Social Capital in Outdoor Orientation Programs

Social capital offers campus recreation professionals a framework to conceptualize the impacts of outdoor orientation programming (OOPs). Using data from The Outdoor Orientation Benchmarking Survey...
Resistance to the infrastructure that governs local literacy and social practices in an English classroom

This work looks at how the infrastructure or conventions of practice and social arrangements govern local classroom literacy practices and how marginalized students resist the infrastructure and ex...
Evaluation of urethrotropic clade meningococcal infection by urine metagenomic shotgun sequencing.

Background Urethral infections caused by an emerging nongroupable (NG) urethrotropic clade of Neisseria meningitidis (Nm) were first reported in the United States in 2015 (the "U.S. NmNG urethritis clade"). Here we evaluate for the presence of other urethral pathogens in men with U.S. NmNG urethritis clade infection. Methods: We evaluated 129 urine specimens collected from men at a sexual health clinic, including 33 from patients with culture-confirmed or suspected urethral Nm infection and 96 specimens in which nucleic acid amplification test detected Neisseria gonorrhoeae (Ng), Chlamydia trachomatis (Ct), both pathogens, or neither pathogen. Nm was detected first by real-time PCR, followed by metagenomic shotgun sequencing of 91 specimens to identify coinfections. Nm genomes were sequenced following selective whole genome amplification when possible. Results: Metagenomic sequencing detected Nm in 16 of 17 specimens from culture-confirmed Nm cases, with no coinfection by other conventional urethral pathogens. Metagenomic sequencing also detected Nm in three Ct positive specimens, one specimen positive for both Ng and Ct, and nine specimens with negative Ng and Ct results, eight of which had suspected Neisseria infections. Nm from culture-confirmed Nm cases belonged to the U.S. NmNG urethritis clade, while Nm identified in other specimens belonged to multiple clonal complexes. Additional urethral pathogens were predominant in non-Nm specimens, including Ng, Ct, Mycoplasma genitalium, Ureaplasma urealyticum, and herpes simplex virus type-2. Conclusions: Coinfection with other conventional urethral pathogens is rare in men with culture-confirmed U.S. NmNG urethritis clade infection and points to the strong association of this clade with disease.
X-Ray Photoelectron Diffraction Study of a High-Temperature Surface Phase Transition on Ge(111)

We have studied a high-temperature surface phase transition on Ge(111) with x-ray photoelectron diffraction (XPD)1. A reversible disordering transition beginning at about 970 K or 240 K below the bulk melting point (Tm) and ending at about 1150 K or 60 K below Tm is observed. The Ge 3p intensity was measured as a function of both emission direction and temperature. Azimuthal XPD data at θ=19°, including nearest-neighbor forward-scattering directions and yielding high surface sensitivity, show an abrupt drop in intensity of -35% over the interval of 970-1150 K. Data taken at θ=55° for which second-nearest-neighbor scattering directions and more bulk sensitivity are involved also exhibit a similar abrupt decrease in intensity over the range of 970-1100K. In conjunction with model single-scattering cluster calculations, these data indicate that the disordering process involves considerably more than the surface double layer of Ge atoms, a conclusion which disagrees with certain prior studies.
Motives for Corporate Philanthropy in El Salvador: Altruism and Political Legitimacy

This paper discusses how Salvadoran companies practice corporate philanthropy in El Salvador, and what might motivate it. First, I briefly discuss three principal theories of corporate philanthropy, and explore some current trends in international corporate philanthropy to highlight some of the motives Salvadoran companies may have to participate in charitable activities. Then, I discuss the history of the Salvadoran private sector to help us understand philanthropic activity today. Next, I suggest that philanthropic acts by Salvadoran firms are driven by altruistic and politically strategic motives, and reflect individualistic and paternalistic attitudes. In the discussion, I include examples of Salvadoran corporate philanthropy as it is practiced today, based on recent field research in El Salvador.
Some facts about Eisenman intrinsic measures. II

We construct a measure hyperbolic manifold which does not admit a Hermitian metric whose Ricci curvature is negatively bounded. We construct a C-connected Stein manifold which is not densely sub-Euclidean or Runge (in the sense of Gromov). We find some conditions under which the Eisenman intrinsic k-measure of a complex manifold does not change when we delete an exclusive divisor of this manifold.
Constant returns to scale: can the market economy exist?

This note argues that the competitive paradigm of neoclassical economics breaks down in the presence of constant returns to scale (CRS). With CRS, all goods can be produced at identical unit costs by all economic agents, making self-production a feasible alternative to market production. In the event, an infinite number of equilibria become possible with a mix of markets and self-production. If labor is the only factor of production, self-production is the only option and the market economy ceases to exist. All too often the competitive paradigm of neoclassical economics has been faulted for its unrealistic assumptions, but rarely for logical inconsistency. These critics have also developed several new variants of economics based on more realistic assumptions. 2 Nevertheless, these critiques have failed to dislodge the competitive paradigm from its preeminent position in economics. Kenneth Arrow (1994: 451) has argued that this is because the competitive paradigm “is still the only coherent account of the entire economy.” Others point to the ideological function of neoclassical economics: in particular, its defense of the capitalism of unfettered markets. 3 This note presents a different critique: it shows that the competitive paradigm is inconsistent with constant returns to scale (CRS). At least since Leon Walras, economists have constructed mathematical models to establish the exact conditions under which a market economy – with fixed resources, tastes and technology – can attain an equilibrium that is also Pareto-efficient. CRS – or the more general assumption of non-increasing returns to scale – has been a cornerstone of all these models. Allyn Young (1928) and later Nicholas Kaldor (1967 and 1972) have shown that equilibrium economics becomes irrelevant in the presence of increasing returns to scale. We argue that neoclassical economics is in trouble even with CRS: and this is a problem that has gone unnoticed. Our concern is not with the existence – or uniqueness and stability – of solutions to the system of equations that define the neoclassical economy. Instead, we ask a more basic question. Can a market economy exist in the presence of CRS?
Parental somatic and germ-line mosaicism for a multiexon deletion with unusual endpoints in a type III collagen (COL3A1) allele produces Ehlers-Danlos syndrome type IV in the heterozygous offspring.

Abstract Ehlers-Danlos syndrome (EDS) type IV is a dominantly inherited disorder that results from mutations in the type III collagen gene (COL3A1). We studied the structure of the COL3A1 gene of an individual with EDS type IV and that of her phenotypically normal parents. The proband was heterozygous for a 2-kb deletion in COL3A1, while her father was mosaic for the same deletion in somatic and germ cells. In fibroblasts from the father, approximately two-fifths of the COL3A1 alleles carried the deletion, but only 10% of the COL3A1 alleles in white blood cells were of the mutant species. The deletion in the mutant allele extended from intron 7 into intron 11. There was a 12-bp direct repeat in intron 7 and intron 11, the latter about 60 bp 5' to the junction. At the breakpoint there was a duplication of 10 bp from intron 11 separated by an insertion of 4 bp contained within the duplicated sequence. The father was mosaic for the deletion so that the gene rearrangement occurred during his early embryonic development prior to lineage allocation. These findings suggest that at least some of the deletions seen in human genes may occur during replication, rather than as a consequence of meiotic crossing-over, and that they thus have a risk for recurrence when observed de novo.
[14] pKa of the protonated schiff base of visual pigments

Abstract The p K a of bovine rhodopsin is greater than 15; that of the long-wavelength-sensitive gecko P521 pigment ranges from 8.4 to 10.5 depending on chloride concentration; and that of octopus, an invertebrate, is 10.5. These p K a values are much higher than are needed just to maintain the Schiff base in its protonated state in the photoreceptor cell. The high p K a of the Schiff base may be at least partially related to a low p K a of its counterion, which would lower the frequency of thermal isomerization of the chromophore and thus lower the dark noise in the photoreceptor cell. After light absorption, the high p K a of the protonated Schiff base of a vertebrate visual pigment must get lowered enough to allow it to deprotonate, a required step in vertebrate visual excitation. This deprotonation step is not required in invertebrate visual excitation.
Mitochondrial ATP synthase subunit c stored in hereditary ceroid-lipofuscinosis contains trimethyl-lysine

The subunit c protein of mitochondrial ATP synthase accumulates in lysosomal storage bodies of numerous tissues in human subjects with certain forms of ceroid-lipofuscinosis, a degenerative hereditary disease. Subunit c appears to constitute a major fraction of the total storage-body protein. Lysosomal accumulation of subunit c has also been reported in putative animal models (dogs, sheep and mice) for ceroid-lipofuscinosis. In humans with the juvenile form of the disease, hydrolysates of total storage-body protein have been found to contain significant amounts of epsilon-N-trimethyl-lysine (TML). TML is also abundant in storage-body protein hydrolysates from affected dogs and sheep. These findings suggested that one or both of the two lysine residues of subunit c might be methylated in the stored form of the protein. The normal subunit c protein from mitochondria does not appear to be methylated. In a putative canine model for human juvenile ceroid-lipofuscinosis, residue 43 of the storage-body subunit c was previously found to be TML. In the present study, subunit c was isolated from the storage bodies of humans with juvenile ceroid-lipofuscinosis, and from sheep and mice with apparently analogous diseases. In all three species, partial amino acid sequence analysis of the stored subunit c indicated that the protein contained TML at residue 43. These findings strongly suggest that specific methylation of lysine residue 43 of mitochondrial ATP synthase plays a central role in the lysosomal storage of this protein.
Bronchial stenosis secondary to epidermolysis bullosa successfully treated with bronchoscopic balloon dilatation

Epidermolysis bullosa rarely affects lower airways. We present a case of lower airway involvement and stenosis successfully managed with flexible bronchoscopy and balloon dilation.
The role of frataxin in doxorubicin-mediated cardiac hypertrophy

Doxorubicin (DOX) is a highly effective anti-neoplastic agent; however, its cumulative dosing schedules are clinically limited by the development of cardiotoxicity. Previous studies have attributed the cause of DOX-mediated cardiotoxicity to mitochondrial iron accumulation and the ensuing reactive oxygen species (ROS) formation. The present study investigates the role of frataxin (FXN), a mitochondrial iron-sulfur biogenesis protein, and its role in development of DOX-mediated mitochondrial dysfunction. Athymic mice treated with DOX (5 mg/kg, 1 dose/wk with treatments, followed by 2-wk recovery) displayed left ventricular hypertrophy, as observed by impaired cardiac hemodynamic performance parameters. Furthermore, we also observed significant reduction in FXN expression in DOX-treated animals and H9C2 cardiomyoblast cell lines, resulting in increased mitochondrial iron accumulation and the ensuing ROS formation. This observation was paralleled in DOX-treated H9C2 cells by a significant reduction in the mitochondrial bioenergetics, as observed by the reduction of myocardial energy regulation. Surprisingly, similar results were observed in our FXN knockdown stable cell lines constructed by lentiviral technology using short hairpin RNA. To better understand the cardioprotective role of FXN against DOX, we constructed FXN overexpressing cardiomyoblasts, which displayed cardioprotection against mitochondrial iron accumulation, ROS formation, and reduction of mitochondrial bioenergetics. Lastly, our FXN overexpressing cardiomyoblasts were protected from DOX-mediated cardiac hypertrophy. Together, our findings reveal novel insights into the development of DOX-mediated cardiomyopathy.
Components of the crude risk ratio.

Miettinen, O. S. (Harvard School of Public Health, Boston, Mass. 02115). Components of the crude risk ratio. Am J Epidemiol 96: 168-172, 1972.—Both in cohort and case-control studies the estimate of the crude risk ratio factors into two important and easily derived components. One is a measure of the strength of confounding, and the other is an estimate of the residual risk ratio in terms of the standardized morbidity (mortality) ratio. For case-control studies the latter seems to be a new and useful "summary relative risk." epidemiologic methods; biometry Risk ratio ("relative risk" (RR)) is a parameter of central interest in epidemiology. It is denned as the ratio of the risk among the exposed to that among the nonexposed, with "risk" referring to some measure of morbidity or mortality and "exposure" and "nonexposure" distinguishing between a pair of alternative experiences or characteristi cs. The data-layouts for its estimation in cohort and case-control studies, respectively, are presented in table 1. With a cohort study the "crude" RR is estimated naturally by the ratio of the two observed rates, i.e., by f>e = (e/F)/(g/H) = eH/gF. The equivalent formula for case-control studies, introduced by Cornfield (1), is the "odds ratio" fic = ad/bc as long as the compared series are independent (unmatched) and the disease is "rare" among exposed as well as nonexposed individuals. These estimates of the crude RR are useful for predictive purposes, but in etiologic research it is necessary to make a distinction between two components of the parameter—one resulting from recognizaAbbreviations: ML, maximum likelihood; RR, risk ratio; SMR, standard morbidity (mortality)
Extremely Low Frequency (ELF) Electromagnetic Wave Propagation

Extremely low frequency (ELF) electromagnetic waves are currently the lowest frequency waves used routinely for wireless communication. Their ability to cover the globe with low transmitted power and to penetrate deeply into electrically conducting material makes them indispensable in a variety of applications, including communication with submerged submarines. ELF waves are also used in a variety of scientific applications, from geological remote sensing to the study of lightning, which is a strong natural ELF wave source. Transmitting controlled electromagnetic power at such long wavelengths is tricky and requires antennas rather different from those used at higher frequencies. ELF waves transmitted near the surface of the Earth are strongly reflected by the ground and the ionosphere, and thus propagate as guided waves in this spherical waveguide. The article discusses ELF transmission and reception, ELF applications, and describes in detail techniques for mathematically modeling, with varying degrees of simplicity and approximation, ELF electromagnetic wave propagation in this Earth-ionosphere waveguide. Keywords: ELF; extremely low frequency; VLF; very low frequency; earth-ionosphere waveguide; waveguide mode theory; submarine communication
Handling Extraordinary Nodes with Weighted T-spline Basis Functions

Abstract To generate analysis-suitable T-splines for arbitrary topologies, in this paper we introduce a new method to deal with extraordinary nodes in the T-mesh. Knot interval duplication method is used to extract knot vectors for the extraordinary nodes and spoke nodes. From defined bicubic weighted T-spline basis functions, the extracted Bezier coefficients are modified to obtain a gap-free T-spline surface. The boundaries shared by the first-ring neighboring Bezier elements are C0-continuous. Then we use biquartic Bezier basis functions with optimized coefficients to increase the surface continuity to G1. Comparison with other methods shows that our method generates T-spline surfaces with better surface continuity for analysis.
Inhibition of NGF deprivation–induced death by low oxygen involves suppression of BIMEL and activation of HIF-1

Changes in O2 tension can significantly impact cell survival, yet the mechanisms underlying these effects are not well understood. Here, we report that maintaining sympathetic neurons under low O2 inhibits apoptosis caused by NGF deprivation. Low O2 exposure blocked cytochrome c release after NGF withdrawal, in part by suppressing the up-regulation of BIMEL. Forced BIMEL expression removed the block to cytochrome c release but did not prevent protection by low O2. Exposing neurons to low O2 also activated hypoxia-inducible factor (HIF) and expression of a stabilized form of HIF-1α (HIF-1αPP→AG) inhibited cell death in normoxic, NGF-deprived cells. Targeted deletion of HIF-1α partially suppressed the protective effect of low O2, whereas deletion of HIF-1α combined with forced BIMEL expression completely reversed the ability of low O2 to inhibit cell death. These data suggest a new model for how O2 tension can influence apoptotic events that underlie trophic factor deprivation–induced cell death.
Medical Ultrasonics: Absorption of Ultrasound by Tissues and Biological Matter

General principles which determine the frequency dependence of both absorption and velocity of ultrasound in matter are outlined and applied to cell suspensions and tissues. The mechanisms which are responsible in the biological case for the experimentally observed frequency dependence of ultrasonic properties are described. They relate predominantly to macromolecular components. Finally, the relationships which pertain to the propagation of ultrasound in heterogeneous tissue complexes are discussed, and consequences for the medical application as a therapeutic tool are considered.
Endosomal transport function in yeast requires a novel AAA‐type ATPase, Vps4p

In a late-Golgi compartment of the yeast Saccharomyces cerevisiae, vacuolar proteins such as carboxypeptidase Y (CPY) are actively sorted away from the secretory pathway and transported to the vacuole via a pre-vacuolar, endosome-like intermediate. The vacuolar protein sorting (vps) mutant vps4 accumulates vacuolar, endocytic and late-Golgi markers in an aberrant multilamellar pre-vacuolar compartment. The VPS4 gene has been cloned and found to encode a 48 kDa protein which belongs to the protein family of AAA-type ATPases. The Vps4 protein was purified and shown to exhibit an N-ethylmaleimide-sensitive ATPase activity. A single amino acid change within the AAA motif of Vps4p yielded a protein that lacked ATPase activity and did not complement the protein sorting or morphological defects of the vps4 delta1 mutant. Indeed, when expressed at normal levels in wild-type cells, the mutant vps4 gene acted as a dominant-negative allele. The phenotypic characterization of a temperature-sensitive vps4 allele showed that the immediate consequence of loss of Vps4p function is a defect in vacuolar protein delivery. In this mutant, precursor CPY was not secreted but instead accumulated in an intracellular compartment, presumably the pre-vacuolar endosome. Electron microscopy revealed that upon temperature shift, exaggerated stacks of curved cisternal membranes (aberrant endosome) also accumulated in the vps4ts mutant. Based on these and other observations, we propose that Vps4p function is required for efficient transport out of the pre-vacuolar endosome.
Report calls for Earth science education “revolution”

With just 7% of U.S. high school students taking classes in Earth and space science, in contrast to 88% studying biology, a new report calls for a “revolution” in Earth science education in the nation's schools, from kindergarten through 12th grade. The June 2002 report, “Blueprint for Change, notes that an increased emphasis on the Earth as a system and the expanded use of Internet resources is causing Earth and space science education to undergo “a revolution that is reshaping the nature and content of what is taught.”
A New Scorpionate Ligand: Tris(4,4-dimethyl-2-oxazolinyl)borate and Its Zirconium(IV) Complexes

The first example of a new class of oxazoline-based scorpionate ligand, tris(4,4-dimethyl-2-oxazolinyl)phenyl borate, [ToM]−, is prepared by reaction of 2-lithio-4,4-dimethyl-2-oxazolide and 0.3 equiv of dichlorophenylborane. The steric bulk of this ligand is greater than that of tris(3,5-Me2-pyrazolyl)borate (Tp*), as quantified by comparison of solid angles of crystallographically characterized zirconium(IV) complexes.
On the power of deterministic reductions to C=P

The counting class C=P, which captures the notion of “exact counting”, while extremely powerful under various nondeterministic reductions, is quite weak under polynomial-time deterministic reductions. We discuss the analogies between NP and co-C=P, which allow us to derive many interesting results for such deterministic reductions to co-C=P. We exploit these results to obtain some interesting oracle separations. Most importantly, we show that there exists an oracleA such that $$ \oplus P^A \nsubseteq P^{C_ = P^A } $$ and $$BPP^A \nsubseteq P^{C_ = P^A } $$ Therefore, techniques that would prove that C=P and PP are polynomial-time Turing equivalent, or that C=P is polynomial-time Turing hard for the polynomial-time hierarchy, would not relativize.
Constructive geometrical reasoning and diagrams

Modern formal accounts of the constructive nature of elementary geometry do not aim to capture the intuitive or concrete character of geometrical construction. In line with the general abstract approach of modern axiomatics, nothing is presumed of the objects that a geometric construction produces. This study explores the possibility of a formal account of geometric construction where the basic geometric objects are understood from the outset to possess certain spatial properties. The discussion is centered around Eu, a recently developed formal system of proof (presented in Mumma (Synthese 175:255–287, 2010)) within which Euclid’s diagrammatic proofs can be represented.
Advances in void swelling and helium bubble physics

Abstract The extensive experimental data base on irradiated austenitic alloys reveals that swelling as a function of dose can be divided into an initial transient period of low swelling rate, followed eventually by a rate of about 1%/dpa. Whereas the transient depends strongly on microstructure, temperature, and composition, the final rate of swelling is nearly independent of these variables. Models of void nucleation and growth are reviewed to demonstrate that they provide theoretical results which are in general agreement with the basic features of the observed swelling behavior. According to these models, the transient period comprises two regimes, one period of nucleation to obtain the void number density at a given irradiation temperature plus a period to reach parity between the dislocation and the void sink strength. The universal swelling rate eventually achieved is characterized by a state of sink parity.
On the use of DSC to assess radiation damage in isotactic poly(methyl methacrylate)

Abstract Stereoregular poly(methyl methacylate) (PMMA) was precipitated from solution and subsequently heat-treated to different crystallinities and/or crystal distributions. Thereafter, the resulting wafers wrer exposed either in air or in static vacuum to high-energy λ-radiation via a Cs-137 source. Using DSC the melting temperatures, heats of fusion, and the crystalline fractions were determined for each irradiated sample. By evaluating either the depression of the melting point or the change in the heat of fusion with dose, a relationship was found between the thermodynamic property, on the one hand, and the chemical plus physical changes, i.e., G (-units), on the other. Present results indicate that G (-units) ≈16 and 10, when evaluated from heat of fusion and cryoscopic measurements, vs. 15, 6, or 1.7 obtained by X-ray diffraction, NMR, or gas analysis, respectively. No superheating effects were noted in the melting point measurements for heating rates up to 50°C/min. The heat of fusion measurements, on the other hand, evidenced a positive correlation, thereby suggesting a G (-units) dependence on heating rate. However, in neither case was reorganization due to premelt recrystallization observed. With these newer methods the partition of radiation-induced effects into chemical and physical changes should be possible for polymers which are not labile enough to undergo premelt recrystallization.
Impurity state electroabsorption studies in oxygen-doped GaAs☆

Abstract Electroabsorption measurements at 300 K made within the band gap on high resistivity GaAs:O are reported. For a crystal with the Fermi level at 0.54 eV, major structure has been detected at 0.52, 0.57, 0.67, 0.75, 0.87, 0.93, 1.03, 1.12, 1.25, 1.36, and 1.39 eV. The 0.67 eV peak appears only in the second harmonic spectrum, indicating no change in permanent dipole for this transition. Polarized light, lock-in amplifier phase angle, and applied field variation data are presented.
Bolometric detectors: optimization for differential radiometers

A differential radiometer can be constructed by placing two matched bolometric detectors in an ac bridge, thus producing a signal that is proportional to the difference in power incident on the two detectors. In conditions of large and time-varying common-mode radiative load, the common-mode response resulting from imperfectly matched detectors can limit the stability of the difference signal. For semiconductor thermistor bolometers we find that the bridge can always be trimmed to null the common-mode response for a given instantaneous value of the radiative load. However, subsequent changes in the common-mode radiative load change the operating point of the detectors, giving rise to a second-order common-mode response. This response can be minimized by increasing the electrical-power dissipation in the detectors at the cost of sensitivity. For the case that we are analyzing, and for mismatches in detector parameters that are typical of randomly paired detectors, common-mode rejection ratios in excess of 103 can be achieved under 20% changes in radiative load.
Charting shark-infested waters: Ethical dimensions of the hostile takeover

Except for a small clutch of academic shark-defenders, everyone seems to know that hostile takeovers are wrong, destructive of people and industries, and damaging to the long-term competitiveness of corporate America. But analysis of the takeover process, absent insider trading, fails to identify any injury that is not replicated elsewhere in the business system. Current suggestions for remedying the situation seem inadequate, ill-fitted to the problem, or hostile to the entire capitalist system. Could it be that it is that system as a whole, or the assumptions underlying it, that is at fault?
Ultrastructural Quantitation of Connective Tissue Changes in Phenytoin-induced Gingival Overgrowth in the Ferret

The gingival overgrowth obtained after maintaining ferrets on PHT appeared to be due entirely to the effect of the drug, for inflammation induced by banding had no influence on the action of PHT in eliciting the overgrowth. The significant change observed was an increase in relative volume of interstitial material (ground substance) in response to PHT. Although there was no appreciable alteration in numbers of cells present in the lesion, PHT had a significant effect on the ultrastructure of fibroblasts. These cells showed a decrease in the relative volume of phagosomes, although organelles concerned with synthesis (the rough endoplasmic reticulum and Golgi zones) were not affected. This suggests that the relative increase in ground substance may reflect decreased breakdown of extracellular material within fibroblasts, while synthetic activity is maintained at a constant level. As a consequence, there is an increase in connective tissue volume--an increase which is manifested as an overgrowth.