cssi/SciSciGPT-SciSciNet huggingface dataset:
Automated Personalized Feedback in Introductory Java Programming MOOCs

Currently, there is a "boom" in introductory programming courses to help students develop their computational thinking skills. Providing timely, personalized feedback that makes students reflect about what and why they did correctly or incorrectly is critical in such courses. However, the limited number of instructors and the great volume of submissions instructors need to assess, especially in Massive Open Online Courses (MOOCs), prove this task a challenge. One solution is to hire graders or create peer discussions among students, however, feedback may be too general, incomplete or even incorrect. Automatic techniques focus on: a) Functional testing, in which feedback usually does not sufficiently guide novices, b) Software verification to find code bugs, which may confuse novices since these tools usually skip true errors or produce false errors, and c) Comparing using reference solutions, in which a large amount of reference solutions or pre-existing correct submissions are usually required. This paper presents a semantic-aware technique to provide personalized feedback that aims to mimic an instructor looking for code snippets in student submissions. These snippets are modeled as subgraph patterns with natural language feedback attached to them. Submissions are transformed into extended program dependence graphs combining control and data flows. We leverage subgraph matching techniques to compute the adequate personalized feedback. Also, constraints correlating patterns allow performing fine-grained assessments. We have evaluated our method on several introductory programming assignments and a large number of submissions. Our technique delivered personalized feedback in milliseconds using a small set of patterns, which makes it appealing in real-world settings.
Influences of Flow Parameters on Pressure Drop in a Patient Specific Right Coronary Artery with Two Stenoses

Blood pressure loss along the coronary arterial length and the local magnitude of the spatial wall pressure gradient (WPG) are important factors for atherosclerosis initiation and intimal hyperplasia development. The pressure drop coefficient (CDP) is defined as the ratio of mean trans-stenotic pressure drop to proximal dynamic pressure. It is a unique non-dimensional flow resistance parameter useful in clinical practice for evaluating hemodynamic impact of coronary stenosis. It is expected that patients with the same stenosis severity may be at different risk level due to their blood pressure situations. The aim of this study is to numerically examine the dependence of CDP and WPG on flow rate and blood viscosity using a patient-specific atherosclerotic right coronary artery model with two stenoses. Our simulation results indicate that the coronary model with a lower flow rate yields a greater CDP across a stenosis, while the model with a higher flow rate yields a greater pressure drop and a greater WPG. Increased blood viscosity results in a greater CDP. Quantitatively, CDP for each stenosis appears to be a linear function of blood viscosity and a decreasing quadratic function of flow rate. Simulations with varying size and location of the distal stenosis show that the influence of the distal stenosis on the CDP across the proximal stenosis is insignificant. In a right coronary artery segment with two moderate stenoses of the same size, the distal stenosis causes a larger drop of CPD than the proximal stenosis does. A distal stenosis located in a further downstream position causes a larger drop in the CDP.
Highly metastatic K7M2 cell line: A novel murine model capable of in vivo imaging via luciferase vector transfection.

Osteosarcoma is rare and little improvement in survival rates has occurred in the last 25 years despite modern chemotherapeutic treatment. Bioluminescent cell lines for the modeling of osteosarcoma have shown success in tracking metastases in vivo, but commonly use adenoviral vectors to transfect the native cell line with bioluminescent reporters. The purpose of this study was to develop an orthotopic model for metastatic osteosarcoma capable of in vivo monitoring of metastatic and primary tumor burden in an immunocompetent mouse and compare that model to its wild type pathogenesis. K7M2 cells were transfected using a plasmid vector and were stable after 12 weeks. Thirty-four female BALB/c mice aged 4-5 weeks underwent orthotopic implantation of either wild type (n = 12) or transfected (n = 22) K7M2 cells in the proximal tibia. Mice were monitored for tumor growth and weekly In Vivo Imaging System (IVIS) imaging was performed to monitor for pulmonary metastasis. Although tumors developed sooner in the wild type group, no significant differences were seen compared to Transfected Group 1 in rate of inoculation, growth rates after first detection, metastatic rate, and time between inoculation and death. This study establishes a new murine model for metastatic osteosarcoma using the K7M2-wt cell line transfected with a non-viral plasmid luciferase vector. The benefits of this preclinical model include an intact immune system and orthotopically driven metastatic disease; this model appears comparable to its wild type counterpart. In the future, the model may be used to examine promising immunomodulatory therapies using bioluminescence in vivo. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.
Data-Based Real-Time Moisture Modeling in Unsaturated Expansive Subgrade in Texas:

Moisture variations significantly influence the strength and stiffness of expansive subgrade soils, shortening the service lives of pavements and increasing the associated maintenance costs. Accura...
Transposition of Tn5 Derivatives in the Chromatically Adapting Cyanobacterium, Fremyella Diplosiphon

In the cyanobacteria a major fraction of the light used for photosynthesis is initially absorbed by the phycobiliproteins. These are highly pigmented proteins which are assembled together with colorless linker polypeptides into organelles called phycobilisomes. These organelles serve as light-harvesting antennae, and funnel exciton energy into the thylakoid membrane to which they are superficially attached. Within the thylakoid membrane cyanobacterial photosynthesis procedes by a mechanism similar to that in higher plants, viz. two photosystems containing chlorophyll awhich cooperate to oxidize water.
Proceedings of the 2006 IEEE/ACM international conference on Computer-aided design

Welcome to the 2006 International Conference on Computer-Aided Design, the world's premier conference in electronic design technology! Our technical program this year is more exciting than ever, addressing several challenges posed by current and future design technologies including power, variability, reliability, yield, system design, and the impact of new devices and materials. We also offer several social events where you can meet colleagues and friends. Both professionals and researchers active in EDA, as well as practicing designers, will benefit from the knowledge provided in both regular paper sessions and embedded tutorials.
Pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals: collateral vessel disease burden and unifocalisation strategies.

IntroductionThe optimal approach to unifocalisation in pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (pulmonary artery/ventricular septal defect/major aortopulmonary collaterals) remains controversial. Moreover, the impact of collateral vessel disease burden on surgical decision-making and late outcomes remains poorly defined. We investigated our centre’s experience in the surgical management of pulmonary artery/ventricular septal defect/major aortopulmonary collaterals.Materials and methodsBetween 1996 and 2015, 84 consecutive patients with pulmonary artery/ventricular septal defect/major aortopulmonary collaterals underwent unifocalisation. In all, 41 patients received single-stage unifocalisation (Group 1) and 43 patients underwent multi-stage repair (Group 2). Preoperative collateral vessel anatomy, branch pulmonary artery reinterventions, ventricular septal defect status, and late right ventricle/left ventricle pressure ratio were evaluated.ResultsMedian follow-up was 4.8 compared with 5.7 years for Groups 1 and 2, respectively, p = 0.65. Median number of major aortopulmonary collaterals/patient was 3, ranging from 1 to 8, in Group 1 compared with 4, ranging from 1 to 8, in Group 2, p = 0.09. Group 2 had a higher number of lobar/segmental stenoses within collateral vessels (p = 0.02). Group 1 had fewer catheter-based branch pulmonary artery reinterventions, with 5 (inter-quartile range from 1 to 7) per patient, compared with 9 (inter-quartile range from 4 to 14) in Group 2, p = 0.009. Among patients who achieved ventricular septal defect closure, median right ventricle/left ventricle pressure was 0.48 in Group 1 compared with 0.78 in Group 2, p = 0.03. Overall mortality was 6 (17%) in Group 1 compared with 9 (21%) in Group 2.DiscussionSingle-stage unifocalisation is a promising repair strategy in select patients, achieving low rates of reintervention for branch pulmonary artery restenosis and excellent mid-term haemodynamic outcomes. However, specific anatomic substrates of pulmonary artery/ventricular septal defect/major aortopulmonary collaterals may be better suited to multi-stage repair. Preoperative evaluation of collateral vessel calibre and function may help inform more patient-specific surgical management.
Oxygen release and oxygen redox

Voltage fade has been a major barrier to the commercialization of a series of high-energy-density battery electrodes for more than a decade. It is now re-examined with advanced characterization techniques, which find its origin is correlated to oxygen activities.
Gene expression in response to optical defocus of opposite signs reveals bidirectional mechanism of visually guided eye growth

Myopia (nearsightedness) is the most common eye disorder, which is rapidly becoming one of the leading causes of vision loss in several parts of the world because of a recent sharp increase in prevalence. Nearwork, which produces hyperopic optical defocus on the retina, has been implicated as one of the environmental risk factors causing myopia in humans. Experimental studies have shown that hyperopic defocus imposed by negative power lenses placed in front of the eye accelerates eye growth and causes myopia, whereas myopic defocus imposed by positive lenses slows eye growth and produces a compensatory hyperopic shift in refractive state. The balance between these two optical signals is thought to regulate refractive eye development; however, the ability of the retina to recognize the sign of optical defocus and the composition of molecular signaling pathways guiding emmetropization are the subjects of intense investigation and debate. We found that the retina can readily distinguish between imposed myopic and hyperopic defocus, and identified key signaling pathways underlying retinal response to the defocus of different signs. Comparison of retinal transcriptomes in common marmosets exposed to either myopic or hyperopic defocus for 10 days or 5 weeks revealed that the primate retina responds to defocus of different signs by activation or suppression of largely distinct pathways. We also found that 29 genes differentially expressed in the marmoset retina in response to imposed defocus are localized within human myopia quantitative trait loci (QTLs), suggesting functional overlap between genes differentially expressed in the marmoset retina upon exposure to optical defocus and genes causing myopia in humans. These findings identify retinal pathways involved in the development of myopia, as well as potential new strategies for its treatment.
Bedrock nitrogen weathering stimulates biological nitrogen fixation

Global ecosystem models suggest that bedrock nitrogen (N) weathering contributes 10-20% of total N inputs to the natural terrestrial biosphere and >38% of ecosystem N supplies in temperate forests specifically. Yet, the role of rock N weathering in shaping ecological processes and biogeochemical fluxes is largely unknown. Here, we show that temperate forest ecosystems underlain by N-rich bedrock exhibit higher free-living N fixation rates than similar forests residing on N-poor parent materials, across sites experiencing a range of climate and tectonic regimes. This seemingly counterintuitive result can be explained by increased accumulation of soil C and P in high bedrock N sites, resulting in increased energy inputs and nutrient supplies to N fixing microorganisms. Our findings advance a novel ecosystem biogeochemical framework that recognizes long-term plant-soil-microbe feedbacks in shaping biogeochemical processes, with potentially widespread implications given the global distribution of bedrock N across Earth's terrestrial biomes.
Ultra-High Step-Up DC/DC Converter Based on Dual-Coupled-Inductors With Low Voltage Stress and Input Current Ripple for Renewable Energy Applications

This paper presents a nonisolated interleaved dc/dc converter with very high voltage gain and low voltage stress for applications requiring a high voltage gain, such as for interfacing photovoltaic or fuel cell with an inverter. In the proposed topology, the voltage multiplier and switched-capacitor are merged to enhance the voltage gain. This feature along with connecting the coupled inductors in series at the output stage increases the voltage conversion ratio. To reduce the input current ripple, two coupled inductors are connected in parallel for sharing the input current equally, resulting in low conduction loss as well as a smaller capacitive filter. To suppress the voltage ringing that stems from the energy stored in the leakage inductance of coupled inductors, the active clamp circuit is implemented in the proposed converter. By applying an integrated regenerative snubber, the leakage energy of coupled inductors not only is recycled to the output stage but also paves the way for soft-switching including zero voltage switching for switches and zero current switching for diodes. The operation modes, design consideration, and comparison verified by experimental results of a 1-kW laboratory prototype of proposed converter are presented. The switches and diodes are implemented using gallium-nitride (GaN) and silicon carbide (SiC) semiconductors, respectively.
Progress in Compensating Pulse Sequences for Quantum Computation

The control of qubit states is often impeded by systematic control errors. Compensating pulse sequences have emerged as a resource efficient method for quantum error reduction. In this review, we discuss compensating composite pulse methods, and introduce a unifying control-theoretic framework using a dynamic interaction picture. This admits a novel geometric picture where sequences are interpreted as vector paths on the dynamical Lie algebra. Sequences for single-qubit and multi-qubit operations are described with this method.
Effects of grain orientations and pre-existing defects on mechanical properties and deformation mechanisms of polycrystalline yttria-stabilized tetragonal zirconia

Abstract Experimental and computational studies have revealed that the mechanical properties and phase transformation behavior of single crystalline zirconia-based shape memory ceramics are significantly dependent on their crystal orientation with respect to the loading direction. However, such effects have not been studied in polycrystalline zirconia-based ceramics. In this work, we utilize molecular dynamics simulations to investigate the effects of grain orientations and manufacturing-produced sub-surface defects on the mechanical properties and deformation mechanisms of polycrystalline yttria-stabilized tetragonal zirconia (YSTZ). Polycrystalline models are generated according to the dominant plastic deformation mechanisms of each individual grain utilizing the single crystal deformation data, and the polycrystalline models mainly comprise phase transformation-dominated grains (P-grain), combined phase transformation- and dislocation-dominated grains (P-D-grain), and dislocation-dominated grains (D-grain). Grain orientations are noted to play a significant role in determining the strength of polycrystalline YSTZ. Martensitic phase transformation is the dominant deformation mechanism in P-grain dominated polycrystals, while in P-D-grain and D-grain dominated cases amorphization and sliding of grain boundaries become the main deformation mechanisms, which can significantly degradate the shape memory behavior. The strength values of polycrystals are considerably decreased due to the addition of a void. Dislocations and phase transformation are observed to nucleate around the void, which accordingly alter the deformation mechanisms observed in defect-free polycrystals.
“If we listen as we read”: cultivating the work of listening

In her vibrant study Race Sounds: The Art of Listening in African American Literature, Nicole Brittingham Furlonge attends to the multifaceted practice of listening through analyses of creative and...
Oesophageal traction diverticulum resulting from pulmonary tuberculosis.

A 56-year-old woman was referred with the primary complaints of bloating and abdominal burning. On prompting, she admitted to a long-standing history of reflux and constant feeling of fullness associated with a decreased appetite and 20-pound weight loss over the prior year. She denied halitosis,
A situative turn in the conversation on motivation theories

Abstract In this commentary I take a situative turn in the theoretical conversation around the question, “Why do people do what they do?” The first section describes in broad strokes what a situative perspective on motivation or engagement entails. Next, I comment on aspects of the five articles as they relate to the history and methods of socio-cognitive and situative approaches to understanding motives to learn. Then, using the central organizing framework of “meaning systems” in situative approaches, I suggest ways that a situative perspective might contribute to ongoing work in the five motivation theories and how some of the authors take steps in that direction.
Design Of A Rapid And Reversible Fluorescence Assay To Detect Covid-19 And Other Pathogens

Abstract We describe a rapid and reusable biophysical method to assay COVID-19 and other pathogens. The method uses fluorescent sensors (i.e. molecular beacons) designed to detect COVID-19 RNA or any RNA of interest, concurrent with an internal control without the need for amplification. The molecular beacons are stem-loop structures in which a ∼10 nucleotide loop region has the complementary sequence of a region of the target RNA, and a fluorophore and quencher are placed on the 5’ and 3’ ends of the stem. The energy of hybridization of the loop with its target is designed to be greater than the hybridization energy of the energy of the stem so that when the beacon encounters its target RNA, the structure opens resulting in dequenching of the fluorophore. Here, we designed a COVID-19 beacon that is completely quenched in its native form and undergoes a 50-fold increase in fluorescence when exposed to nanomolar amounts of synthetic viral oligonucleotide. No changes in intensity are seen when control RNA is added. A control beacon to a human GAPDH RNA, chosen for its high levels in saliva, behaved similar to the COVID-19 beacon. This increase in fluorescence with beacon opening can be completely reversed upon addition of single stranded DNA complementary to COVID-19 beacon loop region. Beacons can be attached to an insert matrix allowing their use in concentrated form and can be made from morphilino oligonucleotides that are resistant to RNases. We present an analysis of the parameters that will allow the development of test strips to detect virus in aerosol, body fluids and community waste. Statement of significance A platform for reusable and rapid detection of COVID-19 RNA and other pathogenic RNAs without the need for amplification or sophisticated instrumentation in a complex environment is described.
The Effect of Communication Mode on Evidence Persuasiveness in Remote Auditor-Client Interactions

This study investigates the effect of communication mode on evidence persuasiveness during remote auditor-client interactions. Consistent with social presence theory, we predict and find that auditors assess management as more competent and an explanation as more plausible and more persuasive when received in a video format compared to email, particularly when the client is identified as “having little training and experience.” This finding suggests that the higher social presence of a neutral video communication may cause auditors to evaluate management more positively. These findings highlight the need for auditors to maintain professional skepticism during video interactions and when interacting with client personnel who are known to have limited training and experience because auditors may overrely on evidence obtained during these interactions. This study is the first of which we are aware to examine auditors’ assessments of client competence and evidence persuasiveness between video versus email communications with the client.
Habitual wayfinding in academic libraries: Evidence from a liberal arts college

Abstract Habitual wayfinding is a revised wayfinding model for academic libraries, where there is a high percentage of repeat users. Using the unique spatial characteristics of a specific academic library, this study explores the wayfinding patterns of repeat users and evaluates the impact of patrons' travel habits on their library space usage. The GIS tool ArcMap is employed to visualize library traffic and detect potential patterns of habitual wayfinding. The impact of habitual wayfinding behaviors on library space usage is analyzed. Findings suggest that travel habits formed through past frequent actions can lead to consistent navigation preferences toward certain function units and significant usage differences even within the same function unit in a library. In addition to proposing this modified wayfinding framework and studying its relevance in explaining library space usage patterns, this study also makes a methodological contribution through a novel approach of detecting potential traffic patterns by visualizing routing data and quantifying its details at the route segment level. The framework, methodology, and findings have important implications for understanding space use in academic libraries and can be valuable to libraries considering conducting space evaluation and space rearrangement projects.
Blast-induced mild traumatic brain injury alterations of corticotropin-releasing factor neuronal activity in the mouse hypothalamic paraventricular nucleus

Blast-induced mild traumatic brain injury (mbTBI) is the most common cause of TBI in US service members and veterans. Those exposed to TBI are at greater risk of developing neuropsychiatric disorders such as posttraumatic stress disorder, anxiety and depressive disorders, and substance use disorders following TBI [1, 2]. Previously, we have demonstrated that mbTBI increases anxiety-like behaviors in mice and dysregulates the stress at the level of corticotropin-releasing factor (CRF) neurons in the paraventricular nucleus (PVN). To expand on how mTBI may dysregulate the stress axis centrally, here PVN CRF neuronal activity was evaluated using whole cell-patch clamp recordings in hypothalamic slices from sham and mbTBI adult male CRF:tdTomato mice 7 days post-injury. We found that mbTBI generally did not affect the neuronal excitability and intrinsic membrane properties of PVN CRF neurons; this injury selectively increased the frequency of spontaneous neuronal firing of PVN CRF neurons localized to the dorsal PVN (dPVN) but not ventral PVN (vPVN). Consistently, mbTBI-induced dPVN CRF hyperactivity was associated with pre- and post-synaptic depression of spontaneous GABAergic transmission onto dPVN CRF neurons suggesting that mbTBI-induced GABAergic synaptic dysfunction may underlie dPVN CRF neuronal hyperactivity and increases in dPVN CRF signaling. The present results provide the first evidence for mbTBI-induced alterations in PVN CRF neuronal activity and GABAergic synaptic function that could mediate hypothalamic CRF dysregulation following mbTBI contributing to stress psychopathology associated with blast injury.
Time-Varying Versus Fixed Weights in Exchange-Market Pressure Indices: Evidence From Tests Using Latin American Data

Years after the 2008 Global Financial Crisis, currencies worldwide are still susceptible to spillovers not only from foreign currency markets, but also from shocks to stock or commodity prices. Understanding these spillovers is essential for policymakers to respond properly, yet defining ?crisis? periods can often be difficult. This paper proposes two alternative weighting schemes that can be used in the creation of an index of ?exchange market pressure? (EMP), constructing them, as well as a more traditional index, for five Latin American nations and three other emerging markets. Vector Autoregressive (VAR) analysis shows that the two new indices are less likely to find evidence of currency spillovers. We therefore conclude that these differences among measures make the new indices less likely to replace the baseline measure in econometric studies.
Waterhammer Analysis by Analog Computers

The basic partial differential equations for unsteady flow are adapted to a standard analog computer. Two waterhammer examples are computed and compared to both experimental and precise analytical results. The analog solution is shown to be accurate. Solution of waterhammer problems on the analog computer provides a design tool of great value.
Performance of redundant and distributed detection systems with processor faults

Examines the performance of signal detectors when processors can have faults. The fault tolerance of two systems, the redundant system and the distributed fusion network, are examined. The optimal fault-tolerant design for each system is presented. The performance of the fault-tolerant systems is compared to the faulty simplex processor. In the absence of processor failures, the redundant system is identical to the simplex processor. However, when failures occur, the redundant system performs better than the simplex processor. The fault-free fusion network does not perform as well as the fault-free simplex processor. However, in the cases examined, when failures occur in systems with many (N> 12) channels, the fusion network performs better than the simplex processor. >
Onboard pilot decision aid for high volume operations in self-controlled airspace

Distributed pilot decision-making plays a critical part in high volume operation in non-controlled/non-radar airports, a concept proposed by the NASA Small Aircraft Transportation System program. Realization of the concept relies on advanced cockpit systems that assist pilots in both information-processing and decision-making. In this paper, we presented the design of an onboard pilot decision aid system, called the Small Aircraft Pilot Assistant, which is dedicated to help pilots perform the high volume operation flight tasks. It increases the cockpit decision-making capacity and pilot situation awareness by automating part of the pilot decision-making process, especially in its early stages of information acquisition and analysis. The pilot tests of the system are conducted using a real-time, multi-aircraft, pilot-in-the-loop simulation system that is presently capable of middle-fidelity HVO simulation.
Online model learning in adversarial Markov decision processes

Consider, for example, the well-known game of Roshambo (Figure 1), or rock-paper-scissors, in which two players select one of three actions simultaneously. One may know that the adversary will base its next action on some bounded sequence of the past joint actions, but may be unaware of its exact strategy. For example, one may notice that every time it selects P, the adversary selects S in the next step; or perhaps whenever it selects R in three of the last four steps, the adversary selects P 90% of the time in the next step. The challenge is that to begin with, neither the adversary function that maps action histories to future actions (may be stochastic), nor even how far back it looks back in the action history (other than an upper bound) may be known. At a high level, this paper is concerned with automatically building such predictive models of an adversary's future actions as a function of past interactions.
The genetic architecture of house fly mating behavior.

This chapter summarizes several experimental approaches used to identify the effects of dominance, epistasis, and genotype-by-environment interactions in the genetic architecture of the mating behavior of the common house fly (Musca domestica L.). Quantitative genetic investigations of mating behavior hold special intrigue for unraveling the complexities of fitness traits, with applications to theory on sexual selection and speciation. Besides being well suited to large-scale quantitative genetic protocols, the house fly has a remarkably complex courtship repertoire, affording special opportunities for studies on communication, social interactions, and learning. Increased additive genetic variances for the courtship repertoire of experimentally bottlenecked populations provided evidence for the presence of dominance and⧸or epistasis. Negative genetic variances in these populations suggested genotype-by-environment interactions, where the environment is the mating partner. Line cross assays of populations that had been subjected to selection for divergent courtship repertoire confirmed that both dominance and epistasis have significant effects. These crosses also showed more directly that the expression of the male's genotype is dependent upon the preferences of his mating partner. Repeatability studies also detailed how males alter their courtship performances with successive encounters within and across females, such that the males learn to improve their techniques in securing copulations. A review of 41 animal behavior studies found that a wide range of traits and taxa have dominance, epistasis, and genotype-y-environment interactions, although house fly courtship may remain a unique model where learning is an intersexually selected trait. Future development of more sophisticated molecular techniques for the M. domestica genome will help unravel the underlying biochemical and developmental pathways of these quantitative genetic interactions for a more complete understanding of the processes of inbreeding depression, outbreeding depression, and pleiotropy.
Lead isotope composition of Central American volcanoes: Influence of the Galapagos plume

[1] Lead isotopic analyses of lavas from Central America, both along and behind the volcanic arc, help to clarify source components in the mantle wedge. Analysis of previous Pb isotopic data had implied that little or no marine sediment lead was added to the Central American source region, as all samples fell within the MORB field, in contrast to other information (e.g., Ba/La, 10Be, 87Sr/86Sr) that indicated a high subduction component. The data presented here include several analyses of local marine sediment, showing it to be exceptionally unradiogenic in Pb and thus permitting high sediment contributions to the mantle source region without significant changes in Pb isotopes. Combined Pb-Nd and Pb-Sr isotopic diagrams clearly illustrate the influence of crustal contamination for samples from Guatemala and Honduras, and of subducted sediment for all lavas of the volcanic front. Samples collected behind the volcanic front are derived from mixing between enriched and depleted mantle sources, and in central Costa Rica (extending to the back arc) overlap Pb, Sr and Nd isotope values for both Cocos Island and some components of the Galapagos hot spot. The restricted geographical occurrence of the enriched mantle signature in Central America, coupled with the persistence of the signal well into the back arc region, imply that these lavas are sampling Galapagos plume-influenced mantle. The presence of this plume component beneath southern Central America and extending to the northeast beneath the Caribbean confirms a Galapagos hot spot origin for this part of Caribbean Plate.
Teen Childbearing and Economics: A Short History of a 25-Year Research Love Affair

Despite its apparent distance from the core topics of economics, economists have been attracted to, and deeply engaged in, research about teen fertility for more than a quarter century. Research has focused on two broad, interrelated issues: the socio-economic consequences of a teen birth and the socio-economic causes of a teen birth. In researching these issues, economists have drawn on and extended basic concepts in economic theory and in applied statistical research. I review those literatures for a non-economist audience and conclude that the research love affair has substantially benefited both parties, although definitive answers to causes and consequences are still elusive.
PHYSICAL ANTHROPOLOGY. Culture and the Direction of Human Evolution: A Symposium. Stanley M. Garn (ed.)

Genetics and Man. C. D. Darlington. Heredity and the Nature of Man. Theodosius Dobzhansky.
Clutter measurements by millimeter-wave radars

An extensive radar clutter database was generated by the University of Michigan's millimeter-wave mobile polarimetric radar system. The database includes millimeter-wave observations of snow, trees, vegetation, and soil and road surfaces at 35, 94, 140, and 215 GHz. The radar measurements were often augmented with close-up observations of the targets including such measurements as water content and surface roughness when appropriate. For each data set, a summary of the observations and photographs of the target scene are provided. The millimeter-wave system consists of truck-mounted radars capable of making observations from a 20 m high platform at incidence angles between 0 and 70 degrees . The 35 and 94 GHz radars are fully polarimetric and capable obtaining the Mueller matrix in situ. >
A Kinematic, Flexure-based Mechanism for Precise, Parallel Motion for the Hertz Variable-delay Polarization Modulator (VPM)

We describe the design of the linear motion stage for a Variable-delay Polarization Modulator (VPM) and of a grid flattener that has been built and integrated into the Hertz ground-based, submillimeter polarimeter. VPMs allow the modulation of a polarized source by controlling the phase difference between two linear, orthogonal polarizations. The size of the gap between a mirror and a very flat polarizing grid determines the amount of the phase difference. This gap must be parallel to better than 1% of the wavelength. A novel, kinematic, flexure-based mechanism is described that passively maintains the parallelism of the mirror and the grid to 1.5 pm over a 150 mm diameter, with a 400 pm throw. A single piezoceramic actuator is used to modulate the gap, and a capacitive sensor provides position feedback for closed-loop control. A simple device that ensures the planarity of the polarizing grid is also described. Engineering results from the deployment of this device in the Hertz instrument April 2006 at the Submillimeter Telescope Observatory (SMTO) in Arizona are presented.
Encephalitozoon sp. in the blue-masked lovebird, Agapornis personata (Reichenow): first confirmed report of microsporidan infection in birds.

SYNOPSIS. A microsporidan tentatively classified as Encephalitozoon sp. on the basis of structure and tinctorial qualities was identified in tissues from a group of blue-masked lovebirds, Agapornis personata (Reichenow). The organism was present in renal tubular epithelial cells, hepatocytes, bile duct epithelial cells, and intestinal epithelial cells. Focal hepatic necrosis occurred around clusters of the organisms but inflammation was minimal or absent in the other infected tissues. Attempts to infect laboratory mice with the organism were unsuccessful. Ultrastructural features were compared with those of E. cuniculi of mammals.
Chondro-osseous morphology of Dermochelys coriacea , a marine reptile with mammalian skeletal features

The marine leatherback turtle, Dermochelys coriacea (Testudines, Dermochelyidae), is the largest known extant reptile, reaching weights >680 kg. It has a cosmopolitan oceanic distribution, nesting in tropical climates but migrating widely into colder temperate and boreal waters1. Recent studies have shown that the leatherback has certain well developed thermoregulatory adaptations: vascular counter-current heat exchangers in the flippers, thick subcutaneous insulation beneath its leathery shell and effective inertial homoiothermy, if not endothermy2,3. Whether this ability to maintain a body temperature higher than the ambient is due to endogenous endothermy or thermal inertia remains unclear4,5. The skeleton of Dermochelys remains extensively cartilaginous even in adult animals6,7, which has been attributed to neoteny secondary to its highly pelagic habitat, based on the assumption that its skeleton resembled that of typical embryonic turtles8. However, up to now there have been no studies of the internal architecture of the leatherback appendicular skeleton. We report here that the chondro-osseous morphology of Dermochelys is unlike that of any other known extant turtle or reptile but is more similar to that of marine mammals, notably Cetacea (whales) and Sirenia (manatees).
Nonapoptotic Function of BAD and BAX in Long-Term Depression of Synaptic Transmission

It has recently been found that caspases not only function in apoptosis, but are also crucial for nonapoptotic processes such as NMDA receptor-dependent long-term depression (LTD) of synaptic transmission. It remains unknown, however, how caspases are activated and how neurons escape death in LTD. Here we show that caspase-3 is activated by the BAD-BAX cascade for LTD induction. This cascade is required specifically for NMDA receptor-dependent LTD but not for mGluR-LTD, and its activation is sufficient to induce synaptic depression. In contrast to apoptosis, however, BAD is activated only moderately and transiently and BAX is not translocated to mitochondria, resulting in only modest caspase-3 activation. We further demonstrate that the intensity and duration of caspase-3 activation determine whether it leads to cell death or LTD, thus fine-tuning of caspase-3 activation is critical in distinguishing between these two pathways.
Observation-based calibration of brain-machine interfaces for grasping

Brain-machine interfaces (BMIs) are increasingly being used in rehabilitation research to improve the quality of life of clinical populations. Current BMI technology allows us to control, with a high level of accuracy, the positioning of robotic hands in space. We have shown previously that it is possible to decode the dexterous movements of fingers during grasping, from noninvasively recorded electroencephalographic (EEG) activity. Due to the absence of overt movement in clinical subjects with impaired hand function, however, it is not possible to construct decoder models directly by simultaneously recording brain activity and kinematics. The mirror neuron system is activated in a similar fashion during both overt movements and observing movements performed by other agents. Here, we investigate action-observation as a strategy to calibrate decoders for grasping in human subjects. Subjects observed while a robotic hand performed grasping movements, and decode models were calibrated using the EEG activity of the subjects and the kinematics of the robotic hand. Decoding accuracy was tested on unseen data, in an 8-fold cross validation scheme, as the correlation coefficient between the predicted and actual trajectories. High decoding accuracies were obtained (r = 0.70 ± 0.07), demonstrating the feasibility of using action-observation as a calibration technique for decoding grasping movements.
Giving Priority to Sex Crime Prosecutions: The Philosophical Foundations of a Feminist Agenda

In light of serious resource constraints, international criminal courts are required to select a small number of crimes for prosecution, leaving others to national courts or, more often, impunity. In recent years, feminists have advocated that such courts give priority to prosecuting sex crimes even at the expense of other serious crimes, including those involving killing. Many international prosecutors have heeded this call, placing special emphasis on the prosecution of sex crimes. At the same time, empirical evidence shows that many people consider sex crimes less serious than crimes resulting in death. There is thus a need to ground the selection of sex crimes for prosecution in the purposes of international criminal law. This essay examines the four primary philosophical bases advanced for international prosecutions – retribution, deterrence, expressivism, and restorative justice – to determine how they inform decisions whether to give priority to sex crime prosecutions. It concludes that retribution and deterrence support such selections at least some of the time, and expressivism and restorative justice provide an even stronger foundation for giving priority to sex crimes.
Local Dynamics of Baroclinic Waves in the Martian Atmosphere

AbstractThe paper investigates the processes that drive the spatiotemporal evolution of baroclinic transient waves in the Martian atmosphere by a simulation experiment with the Geophysical Fluid Dynamics Laboratory (GFDL) Mars general circulation model (GCM). The main diagnostic tool of the study is the (local) eddy kinetic energy equation. Results are shown for a prewinter season of the Northern Hemisphere, in which a deep baroclinic wave of zonal wavenumber 2 circles the planet at an eastward phase speed of about 70° Sol−1 (Sol is a Martian day). The regular structure of the wave gives the impression that the classical models of baroclinic instability, which describe the underlying process by a temporally unstable global wave (e.g., Eady model and Charney model), may have a direct relevance for the description of the Martian baroclinic waves. The results of the diagnostic calculations show, however, that while the Martian waves remain zonally global features at all times, there are large spatiotemporal ...
The First Teenage Pregnancy in the Family: Does It Affect Mothers’ Parenting, Attitudes, or Mother-Adolescent Communication?

To understand the consequences of adolescent pregnancy and childbearing for the family, 189 mothers from three types offamilies were studied: families in which all teenage daughters had never been pregnant, families in which only one teenager was currently pregnant, and families in which only one teenager had delivered a baby within the previous 6 months. in the latter two family types, the current pregnancy or childbearing was the first to occur in the family. Mothers were assessed twice, 13 months apart. Results indicated that, compared with the mothers of never-pregnant teens, the mothers of parenting teens monitored their children less. expected less of their older daughters, and were more accepting of teenage childbearing. Across-time analyses showed that, in families in which the teenager was initially pregnant, mothers monitored and communicated less with their other children and were more accepting of teenage sex after the older daughter gave birth. In families in which the teenager was initially parenting, mothers perceived more difficulty for their teenage daughters and reported being less strict with their other children across time.
Identification with Academics and Motivation to Achieve in School: How the Structure of the Self Influences Academic Outcomes

Authors since William James (1892/1968) have implied that the structure of the self-concept can influence motivation and outcomes in particular domains. The value or importance an individual places on a domain influences how motivated that individual is to expend effort in that domain, ultimately influencing the positivity or negativity of the outcomes in that domain (the outcomes then likewise influence the valuing of that domain). Taking the example of identification with academics (selectively valuing an academic domain as central to the self-concept), we review the importance of psychological centrality and present a theoretical model directly linking the structure of the self to motivation and outcomes, something not explicitly discussed in the literature to date. Finally, strategies are suggested for how to increase a student’s identification with academics, which this theoretical framework suggests should lead to improved motivation to achieve in academics and improved outcomes for students.
The high cost of gunshot and stab wounds.

A 22CALIBER BULLET costs about 10 cents; a knife less than five dollars; and a rifle slightly more than fifty dollars. The low cost and easy accessibility of firearms has created a dangerous situation within our society. Medical educators, particularly surgeons, are well advised to critically evaluate the consequences of this problem in terms of manpower requirements, educational sequelae, and economic hardships. This problem also highlights the need for a continuing review of the social environment in which we as surgeons conduct our work. Inherent in this evaluation lies a commitment to express our views to the public in an effort to curb trends that are disruptive to all facets of society.
QTLs Affecting α-Tocotrienol, α-Tocopherol, and Total Tocopherol Concentrations Detected in the Ogle/TAM O-301 Oat Mapping Population

Consumption of oat (Avena sativa L.) products has been credited with reducing the risk of various diseases. This may be due in part to tocopherol content. Studies have shown variation in α-tocotrienol, α-tocopherol, and total tocopherol levels among oat cultivars, however, the genetic basis of these traits is unknown. The objectives of this study were to examine the genetic mechanisms affecting tocopherol levels in the Ogle1040/TAM O-301 population and to identify quantitative trait loci (QTLs) useful for improving tocopherol levels in oat. The population was grown in Aberdeen and Tetonia, ID, over 4 yr. Alpha-tocotrienol, α-tocopherol, and total tocopherol contents were measured in harvested seed. Mean levels of all three tocopherol measurements were higher from the irrigated Aberdeen location than from the nonirrigated Tetonia location. One major and four minor QTLs were detected, which accounted for a majority of the α-tocotrienol variation across all locations, while six minor QTLs accounted for a majority of the α-tocopherol variation. Only one QTL affecting total tocopherol was detected apart from QTLs affecting α-tocotrienol and α-tocopherol. Overall, we have identifi ed markers linked to QTLs affecting α-tocotrienol and α-tocopherol. Since the highest level of both tocopherols in lines of the population were higher than from previously tested cultivars, these QTLs should be useful to increase specifi c tocopherol levels.