cssi/SciSciGPT-SciSciNet huggingface dataset:
Application of sub-channel modeling to BWR core analysis

Abstract The current trends in nuclear science and engineering, related to modeling and simulation, are towards high-fidelity multi-physics multi-scale simulations to address industry challenge and high impact problems. These trends stimulate the utilization of sub-channel modeling approaches to nuclear reactor cores for both operation applications (core follow and cycle depletion evaluations) and safety applications (transient and accident analysis). While sub-channel modeling of Pressurized Water Reactor (PWR) cores has advanced significantly in last few years, the application of sub-channel modeling to Boiling Water Reactor (BWR) cores is under development. CTF is an improved version of COBRA-TF being developed and maintained by the North Carolina State University (NCSU) in cooperation with Oak Ridge National Laboratory (ORNL), and with support of the US Department of Energy (DOE) Consortium for Advanced Simulation of Light Water Reactors (CASL) as well as from the members of the CTF User’s Group. CTF uses a two-fluid, three-field representation of the two-phase flow, which makes it capable of modeling the high-void flow conditions expected in BWR operation. This paper focuses on applications of CTF to mini- and whole-core BWR calculations on assembly/channel and pin-cell/sub-channel resolved levels as well as on demonstrating that CTF can properly model bypass flow. To increase the confidence in CTF’s BWR modeling capabilities, simulations have been performed using the international Organization for Economic Cooperation and Development (OECD)/US Nuclear Regulatory Commission (NRC) Oskarshamn-2 benchmark, including modeling of a single assembly and a mini-core of 2 × 2 assemblies on a pin-by-pin/sub-channel level, and a full core model on an assembly/channel level. Each model is varied with an increasing amount of detail. Key parameters such as pressure losses and void fraction distribution were analyzed to determine the impact of different levels of detail within a thermal-hydraulic model on the simulation results. The results demonstrated that CTF is capable of modeling BWR core on different spatial resolution levels. The Oskarshamn-2 core simulations was used to further verify and demonstrate CTF’s capabilities of modeling BWRs.
Least-squares horizons with local slopes and multigrid correlations

ABSTRACTMost seismic horizon extraction methods are based on seismic local reflection slopes that locally follow seismic structural features. However, these methods often fail to correctly track ho...
Deciphering Endodontic Microbial Communities by Next-generation Sequencing.

Abstract Introduction Biofilms are present in more than 70% of endodontically diseased teeth. Through the advancements in the next-generation sequencing (NGS) technologies, microbiome research has granted a deeper analysis of the microbial communities living in human hosts. Here, we reviewed previous studies that used NGS to profile the microbial communities of root canals. Methods A total of 12 peer-reviewed articles from PubMed were identified and critically reviewed. The study criteria were as follows: NGS platforms, sequenced bacterial hypervariable regions, teeth diagnosis with available patient information, sample characteristics, collection method, and microbial signatures. Results The most common NGS platforms used were 454 pyrosequencing (Roche Diagnostic Corporation, Risch-Rotkreuz, Switzerland) and Illumina-based technology (Illumina Inc, San Diego, CA). The hypervariable regions sequenced were between the V1 and V6 regions. The patient and sample population ranged from ages 12–76 years and asymptomatic and symptomatic teeth diagnosed with pulp necrosis with or without apical periodontitis. Microbial sampling was conducted directly from the infected pulp or the extracted teeth. The most abundant phyla were Firmicutes, Actinobacteria, Bacteroidetes, Proteobacteria, and Fusobacteria. The most frequently detected genera were Prevotella, Fusobacterium, Porphyromonas, Parvimonas, and Streptococcus. Other notable microbial signatures at different taxa levels were identified but were widely variable between studies. Conclusions Technologies based on high-throughput 16S ribosomal RNA NGS can aid in deciphering the complex bacterial communities of root canal biofilms. Thus far, only a few studies have been published with relatively small sample sizes, variable sample collection protocols, and community analyses methods. Future larger clinical studies are essential with validated standardized protocols for improved understanding of the pathogenic nature of bacterial biofilm communities in root canals.
Pressure-Dependent Dynamics of Polymer Melts from Arrhenius to Non-Arrhenius: The Cooperative Free Volume Rate Equation Tested against Simulation Data

We apply the cooperative free volume (CFV) model to analyze the segmental relaxation times, τ(T,V), of a model 20-mer polymer melt simulated via molecular dynamics over a broad pressure range. Thermodynamic characterization of the 20-mer allows determination of the constant contribution from the hard-core volume (Vhc), which then yields predictions for the free volume, Vfree = V – Vhc. The CFV rate model is based on an activation free energy that increases with the number of cooperating segments, n*, wherein the system’s free volume, Vfree, is what determines n*. The model predicts that on isotherms ln τ vs 1/Vfree is linear with T-dependent slopes. The 20-mer melt data follow this linear behavior at all temperatures. Assuming a fixed activation energy per cooperating segment leads to a very simple analytic form that describes all of the 20-mer melt’s high T behavior, including the Arrhenius to non-Arrhenius transition regime. This form reflects the importance of a gas kinetic contribution as well as both...
Interdisciplinary computational fluid dynamics

Computational Fluid Dynamics (CFD) is the science of predicting fluid velocities and pressure fields via computers, and is a discipline that historically has received enormous attention. CFD model development involves the solution of the partial differential equations describing fluid momentum and continuity balances, and usually requires a fluid dynamicist, physicist, applied mathematician or other computational fluid flow specialist.
Household Food Insecurity and Psychosocial Dysfunction in Ecuadorian Elementary Schoolchildren

Household food insecurity (HFI) is a major global public health and pediatric concern due to its reported association with adverse child nutrition, growth, and health outcomes. Psychosocial dysfunction is a major cause of childhood disability. US and Canadian studies have linked HFI to poorer overall psychosocial dysfunction and specific dysfunction types in school-aged children, i.e., internalizing, externalizing, and attention behaviors. However, it is uncertain whether prior findings are generalizable to low- and middle-income country (LMIC) settings. We conducted a cross-sectional study to explore the association of HFI with psychosocial dysfunction in 6-12-year-old public elementary schoolchildren (n=279) residing in low-income neighborhoods in Quito, Ecuador. Maternal caregivers were interviewed to obtain data on child psychosocial dysfunction (Pediatric Symptom Checklist, PSC), food security (Household Food Security Survey Module), and maternal mental health (SF-36 Mental Composite Summary). Capillary blood samples were obtained from child participants to measure hemoglobin levels. The data were analyzed using general linear models with adjustment for covariates. The results revealed that HFI was associated with significantly higher overall average PSC scores (p=0.002) and with internalizing (p=0.001) and externalizing (p=0.03) but not attention subscale scores. However, anemia was independently associated with PSC attention subscale scores (p=0.015). This is the first study to report on the relationship between HFI and psychosocial dysfunction in school-aged children in a LMIC setting. It highlights the importance of improving policies and programs protecting vulnerable households from HFI. In addition to improving health and nutrition, such improvements could potentially reduce the burden of child psychosocial dysfunction.
Synthesis of a tethered dibenzotetramethyltetraaza[14]annulene macrocycle and the di-nickel(II) derivative

Selective reaction of 2,6-isophthaloyl chloride at the methine positions of two dibenzotetramethyltetraaza[14]annulene (tmtaa) units results in tethering of the macrocycles by either one or two 2,6-isophthaloyl bridging groups. The single tethered dibenzotetramethyltetraaza[14]annulene derivative (SIT-tmtaa) was isolated and characterized by X-ray crystallography, ESI-MS, 1H and 13C NMR. The syn conformation of the two tmtaa units observed in the crystal structure, has tetraaza[14]annulene macrocycles that are more distorted from planarity than in the structure of the parent tmtaa. The di-nickel(II) complex was prepared and characterized by ESI-HRMS, 1H and 13C NMR. DFT computations place the LUMO on the 2,6-isophthaloyl bridge rather than on the tethered tmtaa units and suggest that the 2,6-isophthaloyl tether provides a level of flexibility in the inter tmtaa distances that is comparable to the Pacman Effect observed for tethered porphyrins.
Making Sense of the Evidence: Synthesizing Paleoecological Data

Paleontologists are increasingly concerned with understanding the biology of extinct species and their environments. This has resulted in a proliferation of new techniques and methodologies that provide a wealth of new data for understanding the paleobiology of extinct species and paleoecological relationships between them and their environment. However, combining such analyses to reconstruct an ancient terrestrial ecosystem can present many challenges, particularly when different lines of evidence appear to provide contradictory information. Here, we discuss some of the ways that taphonomy can bias primary data and how awareness of such issues can increase the accuracy of paleoecological studies. We discuss two geographically and temporally disparate fossil sites as examples of paleoecological reconstruction (the Pliocene of East Africa and the early Oligocene of central Chile) and possible ways of reconciling apparently contradictory data and analyses. We conclude that reconstructing ancient ecosystems requires: (1) accurate data and knowledge of potential biases; (2) a thorough understanding of the analytical techniques being applied and their a priori assumptions; and (3) a willingness to recognize non-analog species, habitats, and communities when necessary.
Association of consensus molecular subtypes (CMS) with time to progression (TTP), progression free survival (PFS), and overall survival (OS) with second-line FOLFIRI ± regorafenib in metastatic colorectal cancer (mCRC).

597Background: LCCC1029 was a 2:1 randomized phase II trial of second-line FOLFIRI plus either regorafenib or placebo in mCRC that showed no statistically significant difference in PFS or OS. CMS, ...
Analytical probability propagation method for reliability analysis of general complex networks

Abstract Reliability analysis of complex networks is often limited by large and exponentially increasing computational requirements with system size. In this paper, a new approximated analytical method the authors call the probability propagation method (PrPm) is proposed to calculate the reliability of general complex networks. The proposed method originates from the idea of belief propagation for inference in network graphs to pass a joint probability distribution between nodes in the network. At each step, the distribution is updated and passed as the message to its direct neighbors. After the message passes to the terminal node, an approximation of the network reliability is found. In this paper, the derived updating rules for message passing are provided, as well as a precise formulation of the error compared to the exact solution. The method is applied to three test applications: an example from a previous study on network reliability, a power distribution network, and a general grid network. Results from these applications show high accuracy for the proposed method compared to exact solutions where possible for comparison. In addition, the authors show orders of magnitude increases in computational efficiency of PrPm compared to existing approaches. This includes reducing the computational cost for analyses from an exponential increase in computation time with the size of the system to a quartic increase. The proposed PrPm enables accurate and computationally tractable reliability assessments of larger, complex networks.
Controlling Surface Area of Titanium Nitride Using Metathesis Reactions

A metathesis (exchange) reaction between TiCl3 and Ca3N2 produces phase-pure titanium nitride, TiN, after washing away the CaCl2 byproduct salt. With use of in situ thermocouples, a maximum reaction temperature (Tmax) of 1665 °C is measured for a reaction producing 1.0 g of TiN 0.6 s after initiating the reaction with a resistively heated Nichrome filament. Scanning electron microscopy indicates the formation of micrometer-size TiN particles. Reduction of the reaction size and addition of 3 mol of NH4Cl lowers the reaction temperature to 965 °C and decreases the time the CaCl2 byproduct remains in a molten state from 9 to 0.6 s. This suppresses Ostwald ripening of the TiN, decreasing the crystallite size and increasing its surface area. Line broadening of X-ray diffraction peaks shows a decrease in the average crystallite size from >200 to 30.8 nm, consistent with 20−30-nm-size particles observed using transmission electron microscopy. Nitrogen gas absorption (BET) indicates that the surface area of the T...
INSPECTION AND MAINTENANCE FOR AUTOMATED HIGHWAY SYSTEMS

This paper presents an Automated Highway System (AHS) health- monitoring vehicle, known as the Infrastructure Diagnostic Vehicle (IDV). It also presents a vital AHS maintenance vehicle, known as the Obstacle Removal Vehicle (ORV). The IDV diagnoses the discrete magnetic marker lateral reference system. The ORV provides rapid response to remove debris from the roadway. These two systems combined with the capabilities of an advanced Transportation Management Center (TMC), comprise the maintenance scenario for the live-vehicle demonstration at the National Automated Highway System Consortium (NAHSC) 1997 Proof-of-Technical-Feasibility Demonstration held in San Diego, CA. These systems represent the beginning of a new branch of Intelligent Transportation Systems (ITS) known as Advanced Construction and Maintenance Systems (ACMS).
On the Interpretation of Force-Induced Unfolding Studies of Membrane Proteins Using Fast Simulations

Single-molecule force spectroscopy has proven extremely beneficial in elucidating folding pathways for membrane proteins. Here, we simulate these measurements, conducting hundreds of unfolding trajectories using our fast Upside algorithm for slow enough speeds to reproduce key experimental features that may be missed using all-atom methods. The speed also enables us to determine the logarithmic dependence of pulling velocities on the rupture levels to better compare to experimental values. For simulations of atomic force microscope measurements in which force is applied vertically to the C-terminus of bacteriorhodopsin, we reproduce the major experimental features including even the back-and-forth unfolding of single helical turns. When pulling laterally on GlpG to mimic the experiment, we observe quite different behavior depending on the stiffness of the spring. With a soft spring, as used in the experimental studies with magnetic tweezers, the force remains nearly constant after the initial unfolding event, and a few pathways and a high degree of cooperativity are observed in both the experiment and simulation. With a stiff spring, however, the force drops to near zero after each major unfolding event, and numerous intermediates are observed along a wide variety of pathways. Hence, the mode of force application significantly alters the perception of the folding landscape, including the number of intermediates and the degree of folding cooperativity, important issues that should be considered when designing experiments and interpreting unfolding data.
The Pink Balance Sheet: An Easy Way to Teach Capital Structure Basics

Students of corporate finance must learn the basics of capital structure theory. However, most textbook discussions are confusing and include too many equations. We present a simple model of tax-related capital structure basics that incorporates only three components: a market-value balance sheet, colors that represent risk, and one equation. Students mastering the pink balance sheet should be able to remember easily the various implications of basic capital structure models, including beta relationships such as the Hamada equation.
Theoretical Foundations: Delinquency Risk Factors and Services Aimed at Reducing Ongoing Offending

Utilizing theory to understand youth in the context of their larger environment is of vital importance when assessing youth delinquency risk, and subsequent adjudication service assignment. Using a person-in-environment approach, theories that posit risk factors for delinquency are explored based on individual attributes associated with delinquency, then expand to theories that describe family, peer, and community risk factors, connecting the interrelatedness between the individual and their environment. Theories for services aimed at reducing ongoing delinquency are guided by Carpiano and Daley and begin with the broad ecological framework, then narrow the scope to address mediators between thoughts and actions. A theoretical framework for delinquency risk factors gives us context as to why youth may offend and offers a road map to service providers, while a theoretical framework for services extends the interconnectedness between youth and their environment, and the significance of social learning. Social workers in practice settings are tasked with assessing clients to determine risk factors, develop treatment goals, and link with specialized services. Social workers and agencies should develop assessments and services that are theory driven, and incorporate youth, family, peer, and community components.
Spin Delocalization, Polarization, and London Dispersion Forces Govern the Formation of Diradical Pimers.

Some free radicals are stable enough to be isolated, but most are either unstable transient species or exist as metastable species in equilibrium with a dimeric form, usually a spin-paired sigma di...
Design of a Battery Controller for Urban Photovoltaic Light System

Light Emitting Diode (LED) and a more recent technology Organic Light Emitting Diode (OLED) are candidates for playing a major role in light applications systems. Recent technological advances and cost decrease of LEDs made their application an advantageous choice in commercial spaces and outdoor lighting systems. Although lighting systems powered by photovoltaic (PV) energy, they haven’t been widely used, due to their high upfront cost. But the recent dramatic decrease of PV panels and LED lighting systems, renewed the interest for this technology for street lighting systems in Algeria. This paper presents the design and application of a battery charge controller for PV lighting systems based on LED technology. In this work, a solar PWM controller based on an ATmega32S microcontroller is described along with a boost DC-DC converter design and tests.
Epigenetic biomarkers and preterm birth

Preterm birth (PTB) is a major public health challenge, and novel, sensitive approaches to predict PTB are still evolving. Epigenomic markers are being explored as biomarkers of PTB because of their molecular stability compared to gene expression. This approach is also relatively new compared to gene-based diagnostics, which relies on mutations or single nucleotide polymorphisms. The fundamental principle of epigenome diagnostics is that epigenetic reprogramming in the target tissue (e.g. placental tissue) might be captured by more accessible surrogate tissue (e.g. blood) using biochemical epigenome assays on circulating DNA that incorporate methylation, histone modifications, nucleosome positioning, and/or chromatin accessibility. Epigenomic-based biomarkers may hold great potential for early identification of the majority of PTBs that are not associated with genetic variants or mutations. In this review, we discuss recent advances made in the development of epigenome assays focusing on its potential exploration for association and prediction of PTB. We also summarize population-level cohort studies conducted in the USA and globally that provide opportunities for genetic and epigenetic marker development for PTB. In addition, we summarize publicly available epigenome resources and published PTB studies. We particularly focus on ongoing genome-wide DNA methylation and epigenome-wide association studies. Finally, we review the limitations of current research, the importance of establishing a comprehensive biobank, and possible directions for future studies in identifying effective epigenome biomarkers to enhance health outcomes for pregnant women at risk of PTB and their infants.
Data of the constructivist practices in the learning environment survey from engineering undergraduates: An exploratory factor analysis.

Abstract This paper presents the dataset of a questionnaire on first-year engineering undergraduates’ perceptions of constructivist practices in the learning environment. The questionnaire with a 5-Likert scale was adapted from previous research. The sample consisted of 293 first-year engineering undergraduates in the southwest region of the United States. The online questionnaire was sent to participants who completed it voluntarily at the end of Fall 2019. A total of 274 of 293 participants completed the questionnaire with a response rate of 93.515%. Exploratory factor analysis was conducted to test the underlying factor structure of the questionnaire, which serves as a good reference for future research.
The developmental cascade of early parenting, emergence of executive functioning, and emotional symptoms across childhood.

Many studies focus on proximal associations between parental sensitivity and emotional well-being in early childhood, with less data examining how parenting in infancy predicts children's emotional trajectories across childhood, in particular negative emotional symptoms of anxiety and depression. Thus, this study utilized data from The Family Life Project (N = 1015), a prospective study of child development in rural poverty, and assessed whether sensitive parenting in the first 4 years of life predicted child internalizing emotional symptoms (i.e., anxiety and depression) from kindergarten to fifth grade and whether early child executive functioning mediated this relationship. Path models indicated that observation of sensitive parenting predicted a decrease in teachers' report of child negative emotional symptoms over time and predicted fewer negative emotional symptoms in fifth grade. Moreover, though executive functioning performance did not mediate change in symptoms over time, executive functioning did mediate the relationship between sensitive parenting and fifth-grade symptoms, suggesting that executive functioning is one mechanism by which early sensitive parenting buffers long-term emotional development. Findings highlight the importance of early parenting and executive functioning in development of anxiety and depression symptoms and suggests potential targets for transdiagnostic intervention.
Using hotspot analysis to prioritize security efforts in Colombian critical infrastructure, a focus on the power grid

To effectively protect critical infrastructure, it is essential to identify vulnerable areas for priority protection. The use of geographic information systems has increased over the last few decades for crime activity and the identification of delinquency hotspots. This study analyzes the areas of a power grid that are exposed to a higher than the average risk of terrorist attacks. One of the concerns for operation managers and policy makers is that subversive groups may have “inside” information to perform the attacks and create a critical failure that puts more pressure on the operational condition of the power grid. We use exploratory spatial data analysis (ESDA) and information from the Colombian power grid to prompt the question: why hotspots emerge in some parts of the power grid, but not in others? The theoretical framework of attacks in the power grid operation exists but need to be corroborated with historical events that reflect such possible way of action. To this end, we perform a Getis-Ord Gi* hotspot analysis to direct attention to areas that are both under attack and critical in terms of operational risks that could affect the reliability and provision of critical services such as power generation and distribution. This subnational case study of Colombia uses data from XM and InterColombia (managers and operators of the Colombian power grid) to identify the areas of electrical infrastructure that have been most attacked and explain the motivations at the local level that the subversive groups have had to attack these areas.
Assessment of hospitalization rates, factors associated with hospitalization and in-patient mortality in pediatric patients with cystic fibrosis.

Abstract Introduction Cystic fibrosis (CF), an inherited autosomal recessive disease that results in the accumulation of mucus and damage primarily to the respiratory and digestive tracts is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. In the United States, it has been estimated that CF occurs in 1 out of 3500 infants. The objective of this study was to explore the patient and hospital characteristics associated with CF hospitalizations and inpatient mortality in pediatric CF patients. Methods Utilizing the National Inpatient Sample database from 2008 to 2017, a retrospective cohort study was conducted to analyze the hospitalization rates, associated factors, and the inpatient mortality of CF patients 0–17 years of age. Hospitalizations with a diagnosis of CF were identified with ICD-9-CM and ICD-10-CM codes. Adjusted survey logistic regression models were utilized to determine factors associated with CF hospitalizations and in-hospital deaths in CF patients. Results There were a total of 98,660 (about 0.2%) CF hospitalizations in patients 17 years of age or younger during the study period. Non-Hispanic (NH) White CF patients had the highest prevalence of CF (26.30 per 10,000 hospitalizations). The prevalence of inpatient deaths were highest among those identified as NH-Others and NH-Blacks (71.35 and 68.83 per 10,000 CF hospitalizations, respectively. When compared with NH-White category, those belonging to NH-Black, Hispanic and Other racial/ethnic sub-group had reduced odds of being hospitalized with CF. Discussion Despite our finding of an increased likelihood of being hospitalized for CF among NH-White and male pediatric patients, no association between race or sex and CF inpatient death was observed when adjusted for covariates. More research is needed to determine the impact of sex and race on CF mortality rates.
Hemipelvectomy (Hindquarter Amputation)

The term “hemipelvectomy” implies the removal of the right or left hemipelvis along with the ipsilateral extremity and suggests that the division of the bone was carried through the sacroiliac joint. When part of the posterior portion of the iliac bone is preserved, the procedure is called “conservative hemipelvectomy.” A conservative hemipelvectomy suffices for most tumors requiring this amputation. Although hemipelvectomy has been performed rarely for benign conditions extensively involving the soft tissues and underlying bones at the level of the hip, it is usually performed for malignant tumors located in the proximal thigh near the level of the inguinal ligament or in the iliac fossa, or tumors infiltrating the wall of the lesser pelvis that are so extensive in terms of soft tissue and osseous involvement that they cannot be conservatively removed completely with preservation of the extremity. The abdominoinguinal incision has made hemipelvectomy unnecessary for most tumors located in the iliac fossa or in the wall of the lesser pelvis. Tumors located in the buttock that are not resectable with a more conservative operation can be managed with this procedure, but an anterior flap is required. The unqualified term “hemipelvectomy” implies the use of a posterior flap.
Case 9: Interscalene Block a Concern in Cardiac Patients?

An 83-year-old man (81 kg and 172 cm) is scheduled for an elective right shoulder arthroscopy with rotator cuff tear repair. His past medical history is significant for coronary artery disease. He has had two prior coronary artery bypass surgeries, the latest 12 years ago. Hypertension and hyperlipidemia are well controlled. On questioning, he denies any symptoms of chest pain or shortness of breath with exertion. EKG shows normal sinus rhythm and a right bundle branch block. A stress echocardiogram performed 2 weeks ago showed a normal ejection fraction with no signs of ventricular wall motion abnormalities. His oxygen saturation is 97% and his vital signs are normal. A chest X-ray was not ordered as his chest exam is normal except for decreased air entry at the base of the right lung.
Pseudarthrosis of a thirty-nine-year-old dens fracture causing myelopathy. A case report.

Treatment of fractures of the odontoid process of the axis (the dens) has the potential to stabilize a critical injury or result in a high degree of morbidity or even death. We present the case of a patient in whom myelopathy developed more than thirty-nine years after he sustained a dens fracture while playing football. This case is unique because of the prolonged asymptomatic interval between the injury and the development of the myelopathy, during which time the patient worked as a manual laborer. The late onset of progressive myelopathy after a dens fracture is considered uncommon1,2 and, to our knowledge, this case represents the second longest delay between a dens fracture and the onset of myelopathy in the English-language literature. The myelopathy resolved after surgical stabilization, and the four-year clinical and radiographic follow-up data are presented. Our patient was notified that data concerning this case would be submitted for publication. Afifty-five-year-old man who performed manual labor working as a machine operator presented to an orthopaedic surgeon with a chief symptom of difficulty using his upper and lower limbs. He reported the insidious onset of increasing neck pain at the base of the skull over the preceding several years, which had been associated with progressively worsening bilateral upper and lower-extremity weakness for the previous three months. The patient had been unable to work or participate in his normal activities of daily living for approximately two months because of the arm weakness. The musculoskeletal history revealed that he had sustained a cervical spine fracture at the age of sixteen years while playing football, which was treated with a neck brace for approximately three months. On physical examination, the patient appeared to be a well-developed, well-nourished man with a range of motion of the neck of 45° of rotation …
Astronomy: Pluto leads the way in planet formation

Images from the Hubble Space Telescope cast new light on the orbits, shapes and sizes of Pluto's small satellites. The analysis comes just before a planned reconnaissance by the first spacecraft to visit them. See Article p.45 With NASA's New Horizons probe fast approaching Pluto for its flyby on 14 July, Mark Showalter and Douglas Hamilton present new results from the Pluto system and offer some predictions about what the spacecraft might observe. Pluto's four small moons — Styx, Nix, Kerberos and Hydra —follow near-circular, near-equatorial orbits around the central 'binary planet' comprising Pluto and its large moon, Charon. In an analysis of Hubble Space Telescope images, Showalter and Hamilton demonstrate that Styx, Nix and Hydra are tied together by a three-body resonance. Perturbations by the other bodies inject chaos into this otherwise stable configuration so that Nix and Hydra rotate chaotically, driven by the large torques of the Pluto–Charon binary. Nix and Hydra have bright surfaces similar to that of Charon. Kerberos may be much darker.
An Analysis of the Relationship between Price and Variance for Homogeneous Housing Stock

This study examines the structure of price variance for homogeneous residential housing stock, where homogeneous is defined as economically equivalent, not necessarily physically identical. Assessed values, obtained from ad valorem tax rolls, are used as the basis for identifying properties considered to be economically equivalent. From these data an investigation of the distribution of sale price and variance for housing in selected value ranges is conducted. Subsequently, ANOVA is performed to determine the composition of variance through time and across cities within one metropolitan housing market.In line with conventional wisdom, we find that variance increases with price over the entire data set. The increase, however, is not constant nor does it exhibit a simple proportional relationship to price. Variance increases at an increasing rate in the lower to mid-price ranges and continues to increase but at a decreasing rate in the upper price ranges. From this it was determined that the functional rela...
Acoustic wave propagation in oil shale. 1. Experiments

Abstract This study examines the propagation characteristics of compressional (P) and shear (S) acoustic waves through cored and broken Green River oil shale specimens. Both compressional and shear wave velocities (Vp and Vs) are sensitive to shale organic content, showing a monotonic decrease with increasing organic content in the range 30–200 L/t. Trends in the dependence of Vp and Vs on temperature are explained by thermal alterations in the shale matrix which include release of free and bound water molecules, pyrolysis of organic matter and re-cementation of the shale matrix by the products of pyrolysis. The temperature dependence of Vp and Vs is less pronounced when the acoustic energy propagates in a plane parallel to the shale bedding planes. Channelling of acoustic energy via mineral-rich layers has been invoked to explain the anisotropy. The degree of anisotropy is also dependent on shale organic content; the differences becoming less pronounced at high levels of organic content. Data on Vp and Vs for burnt and retorted shales show minimal temperature dependence, although these values are sensitive to the initial organic content of the material. Finally, measurements on broken pieces of shale reveal the expected increase in Vp and Vs with increasing compaction pressure. The decrease in Vpand Vs with decreasing particle size down to 0.6−0.3 mm is rather anomalous and can be explained only by the presence of a large number of narrow voids in the material.
Inertial Motion, Explanation, and the Foundations of Classical Spacetime Theories

I begin by reviewing some recent work on the status of the geodesic principle in general relativity and the geometrized formulation of Newtonian gravitation. I then turn to the question of whether either of these theories might be said to “explain” inertial motion. I argue that there is a sense in which both theories may be understood to explain inertial motion, but that the sense of “explain” is rather different from what one might have expected. This sense of explanation is connected with a view of theories—I call it the “puzzleball view”—on which the foundations of a physical theory are best understood as a network of mutually interdependent principles and assumptions.
Comets, interstellar clouds and star clusters

The association of comets with star formation in clusters is elaborated. This hypothesis is also used to explain origin and evaluation of the Oort cloud, the composition of comets, and relationships between cometary and interstellar molecules.
Ewing's sarcoma of bone tumor cells produces MCSF that stimulates monocyte proliferation in a novel mouse model of Ewing's sarcoma of bone

Ewing's sarcoma of bone is a primary childhood malignancy of bone that is treated with X-radiation therapy in combination with surgical excision and chemotherapy. To better study Ewing's sarcoma of bone we developed a novel model of primary Ewing's sarcoma of bone and then treated animals with X-radiation therapy. We identified that uncontrolled tumor resulted in lytic bone destruction while X-radiation therapy decreased lytic bone destruction and increased limb-length asymmetry, a common, crippling complication of X-radiation therapy. Osteoclasts were indentified adjacent to the tumor, however, we were unable to detect RANK-ligand in the Ewing's tumor cells in vitro, which lead us to investigate alternate mechanisms for osteoclast formation. Ewing's sarcoma tumor cells and archival Ewing's sarcoma of bone tumor biopsy samples were shown to express MCSF, which could promote osteoclast formation. Increased monocyte numbers were detected in peripheral blood and spleen in animals with untreated Ewing's sarcoma tumor while monocyte number in animals treated with x-radiation had normal numbers of monocytes. Our data suggest that our Ewing's sarcoma of bone model will be useful in the study Ewing's sarcoma tumor progression in parallel with the effects of chemotherapy and X-radiation therapy.
Stem Cells and Progenitor Cells for Tissue-Engineered Solutions to Congenital Heart Defects

Synthetic patches and fixed grafts currently used in the repair of congenital heart defects are nonliving, noncontractile, and not electrically responsive, leading to increased risk of complication, reoperation, and sudden cardiac death. Studies suggest that tissue-engineered patches made from living, functional cells could grow with the patient, facilitate healing, and help recover cardiac function. In this paper, we review the research into possible sources of cardiomyocytes and other cardiac cells, including embryonic stem cells, induced pluripotent stem cells, mesenchymal stem cells, adipose-derived stem cells, umbilical cord blood cells, amniotic fluid-derived stem cells, and cardiac progenitor cells. Each cell source has advantages, but also has technical hurdles to overcome, including heterogeneity, functional maturity, immunogenicity, and pathogenicity. Additionally, biomaterials used as patch materials will need to attract and support desired cells and induce minimal immune responses.
Lap time variation and executive function in older adults: the Baltimore Longitudinal Study of Aging

Background: poor cognitive and motor performance predicts neurological dysfunction. Variable performance may be a subclinical indicator of emerging neurological problems. Objective: examine the cross-sectional association between a clinically accessible measure of variable walking and executive function. Methods: older adults aged 60 or older from the Baltimore Longitudinal Study of Aging (n= 811) with data on the 400-m walk test and cognition. Based on ten 40-m laps, we calculated mean lap time (MLT) and variation in time across ten 40-m laps (lap time variation, LTV). Executive function tests assessed attention and short-term memory (digit span forward and backward), psychomotor speed [Trail Making Test (TMT) part A] and multicomponent tasks requiring cognitive flexibility [TMT part B, part B-A (Delta TMT) and digit symbol substitution test (DSST)]. Multivariate linear regression analysis examined the cross-sectional association between LTV and executive function, adjusted for MLT, age, sex and education, as well as the LTV × MLT interaction. Results: the LTV was univariately associated with all executive function tests except digit span (P< 0.001); after adjustment, the association with TMT part A remained (standardised β= 0.142, P= 0.002). There was an interaction between MLT and LTV; among fast walkers, greater LTV was associated with a greater Delta TMT (β for LTV × MLT =�1.121, P= 0.016) after adjustment. Conclusion: at any walking speed, greater LTV is associated with psychomotor slowing. Among persons with faster walking speed, variation is associated with worse performance on a complex measure of cognitive flexibility. A simple measure of variability in walking time is independently associated with psychomotor slowing.
Lrp4 is a retrograde signal for presynaptic differentiation at neuromuscular synapses

Lrp4 acts bidirectionally and coordinates synapse formation by binding agrin, activating MuSK and stimulating postsynaptic differentiation, and functioning in turn as a muscle-derived retrograde signal that is necessary and sufficient for presynaptic differentiation. Developing neuromuscular junctions are most frequently studied from the postsynaptic side — through molecules that orchestrate muscle maturation. Now Steve Burden and colleagues show that one of these factors — the low-density lipoprotein receptor-related protein 4 (Lrp4) — also functions in the other direction, as a retrograde signal from the muscle that induces the differentiation of the presynaptic, neuronal compartment. Defects in this signalling pathway may underlie neurodegenerative disorders such as amyotrophic lateral sclerosis and ageing-related sarcopenia, which often start with fragmentation or withdrawal of motor-nerve terminals from muscles. Motor axons receive retrograde signals from skeletal muscle that are essential for the differentiation and stabilization of motor nerve terminals1. Identification of these retrograde signals has proved elusive, but their production by muscle depends on the receptor tyrosine kinase, MuSK (muscle, skeletal receptor tyrosine-protein kinase), and Lrp4 (low-density lipoprotein receptor (LDLR)-related protein 4), an LDLR family member that forms a complex with MuSK, binds neural agrin and stimulates MuSK kinase activity2,3,4,5. Here we show that Lrp4 also functions as a direct muscle-derived retrograde signal for early steps in presynaptic differentiation. We demonstrate that Lrp4 is necessary, independent of MuSK activation, for presynaptic differentiation in vivo, and we show that Lrp4 binds to motor axons and induces clustering of synaptic-vesicle and active-zone proteins. Thus, Lrp4 acts bidirectionally and coordinates synapse formation by binding agrin, activating MuSK and stimulating postsynaptic differentiation, and functioning in turn as a muscle-derived retrograde signal that is necessary and sufficient for presynaptic differentiation.
Image restoration for a class of linear spatially-variant degradations

Abstract The Mellin transform is introduced as a technique for restoring images degraded by a class of spatially-variant degradations. This class includes the coma aberration and tilt in a cylindrical lens system. A technique for computing the Mellin transform via the fast Fourier transform is presented as well as examples of restorations by the use of the computer for the tilt degradation.
An RNN-based channel classification for Mandarin speech recognition over GSM/PSTN transmission environments

This paper is concerned with adopting an RNN (Recurrent Neural Network)-based channel classification technique for improving the robustness of speech recognition over GSM (Global System for Mobile Communication) and PSTN (Public Switched Telephone Network) transmission channels. We apply the RNN-based channel classification to select a most likely HMM from pre-trained HMMs that are trained for each specific channel environment. A broad-class discrimination is incorporated into the RNN-based channel classification by rejecting the disturbed frames of testing speech for improving the performance. By applying the proposed technique we obtained a drop on the average word error rate by about 24% for the recognition of the abbreviated Taiwan stock names over the conventional HMM-based scheme. Experimental results show it is an efficient framework to enhance the robustness across different channel environments.
Statistical pose estimation of land targets in SAR

This paper explores statistical pose estimation in SAR ATR using a recently proposed training method based on information theory. The theory of training with information theoretic learning is briefly summarized. Different pose estimator topologies and training criteria are employed. Experimental results in the MSTAR I and II show that our proposed method is capable of producing 1-DOF and 2-DOF pose estimations and we show the dependence of the training parameters on performance.
Duties of the Teacher.

This checklist consists of the headings from a long analysis of this topic, consisting of the checklist plus explanatory text for each of the checkpoints (Journal of Personnel Evaluation in Education, 1994, vol. 8, no.2, pp.151-184). The checklist provides a good overview of the whole approach, however, and is based on a complex evaluative theory, which includes, for example, the ethical principle that one cannot evaluate teachers by looking at the teaching style they employ, except insofar as this is prescribed by the accepted duties of a teacher. They can use much or little lecturing, question asking, etc., no matter what the research shows, just so long as they successfully cause the acquisition of valuable knowledge, skills, and attitudes in the areas for which they are responsible, at a rate that is appropriate or better for comparable students, within current ethical, resource, and legal parameters. Teachers have no duty to teach using a particular style, only to teach successfully. It is weakly sequential because there are socio-political reasons for each item’s placement; e.g., the main reason for placing item 1 first was the perceived climate for acceptance by school boards, state and federal agencies, and parents.
A novel computer-aided detection system for pulmonary nodule identification in CT images

Computer-aided detection (CADe) of pulmonary nodules from computer tomography (CT) scans is critical for assisting radiologists to identify lung lesions at an early stage. In this paper, we propose a novel approach for CADe of lung nodules using a two-stage vector quantization (VQ) scheme. The first-stage VQ aims to extract lung from the chest volume, while the second-stage VQ is designed to extract initial nodule candidates (INCs) within the lung volume. Then rule-based expert filtering is employed to prune obvious FPs from INCs, and the commonly-used support vector machine (SVM) classifier is adopted to further reduce the FPs. The proposed system was validated on 100 CT scans randomly selected from the 262 scans that have at least one juxta-pleural nodule annotation in the publicly available database - Lung Image Database Consortium and Image Database Resource Initiative (LIDC-IDRI). The two-stage VQ only missed 2 out of the 207 nodules at agreement level 1, and the INCs detection for each scan took about 30 seconds in average. Expert filtering reduced FPs more than 18 times, while maintaining a sensitivity of 93.24%. As it is trivial to distinguish INCs attached to pleural wall versus not on wall, we investigated the feasibility of training different SVM classifiers to further reduce FPs from these two kinds of INCs. Experiment results indicated that SVM classification over the entire set of INCs was in favor of, where the optimal operating of our CADe system achieved a sensitivity of 89.4% at a specificity of 86.8%.
Ordered conformations in bis(amino acid) derivatives of 1,1′-ferrocenedicarboxylic acid

Abstract Two bis(amino acid) derivatives of 1,1′-ferrocenedicarboxylic acid were characterized by IR, 1 H NMR and 13 C NMR spectroscopy. Each was found to adopt an ordered, intramolecularly hydrogen bonded conformation in CHCl 3 .