cssi/SciSciGPT-SciSciNet huggingface dataset:
Stress and Mental Health in Graduate School: How Student Empowerment Creates Lasting Change

This article describes an ongoing initiative of the Department of Chemistry (Chem. Dept.) at the University of Minnesota (UMN) to support the mental health of graduate students. With the increasing pressure on students to carry out novel research, publish articles, learn a broad range of skills, and look for career opportunities, the levels of stress, anxiety, and depression among graduate students are on the rise. For tackling these issues, the UMN Chem. Dept. has adopted an approach that heavily relies on the involvement of graduate students and student empowerment. This contribution describes the results of a collaboration between a student group (Community of Chemistry Graduate Students, CCGS), the director of graduate studies of the Chem. Dept., and mental health professionals at the UMN campus health service, to provide strategies for ensuring a welcoming and productive departmental climate. It describes the events that CCGS has hosted to help to improve the mental health of students, and raise awar...
NKX2-1-AS1 negatively regulates CD274/PD-L1, cell-cell interaction genes, and limits human lung carcinoma cell migration

The function of most long noncoding RNAs (lncRNAs) is unknown. However, recent studies reveal important roles of lncRNAs in regulating cancer-related pathways. Human antisense lncRNA-NKX2-1-AS1 partially overlaps the NKX2-1/TTF1 gene within chromosomal region 14q13.3. Amplification of this region and/or differential expression of genes therein are associated with cancer progression. Herein we show higher levels of NKX2-AS1 and NKX2-1 in lung adenocarcinomas relative to non-tumor controls but no correlation between NKX2-1-AS1 and NKX2-1 levels across specimens, or with amplification of the 14q13.3 region, suggesting that NKX2-1-AS1 and NKX2-1 are independently regulated. Loss-and-gain of function experiments showed that NKX2-1-AS1 does not regulate NKX2-1 expression, or nearby genes, but controls genes in trans. Genes up-regulated by NKX2-1-AS1-knockdown belong to cell adhesion and PD-L1/PD-1 checkpoint pathways. NKX2-1-AS1 negatively regulates endogenous CD274/PD-L1, a known target of NKX2-1, and the transcriptional activity of -1kb-CD274 promoter-reporter construct. Furthermore, NKX2-1-AS1 interferes with NKX2-1 protein binding to the CD274-promoter, likely by NKX2-1 protein-NKX2-1-AS1 interactions. Finally, NKX2-1-AS1 negatively regulates cell migration and wound healing, but not proliferation or apoptosis. These findings support potential roles of NKX2-1-AS1 in limiting motility and immune system evasion of lung carcinoma cells, highlighting a novel mechanism that may influence tumorigenic capabilities of lung epithelial cells.
Genistein inhibits glucose uptake and induces autophagy in ovarian cancer cells.

455 Objectives: Genistein, a naturally occurring isoflavenoid abundant in soy products, has anti-neoplastic activity in multiple tumor types in vitro. There are several mechanisms reported for genistein’s anti-neoplastic activity, including inhibition of tyrosine kinase activation, and induction of apoptosis. Constitutive activation of the tyrosine kinase Akt contributes towards inhibition of apoptosis and chemoresistance in ovarian cancer. Activation of Akt has also been shown to enhance aerobic glycolysis in cancer cells. The purpose of this study was to determine if genistein is cytotoxic to ovarian cancer cells, and if this occurs through inhibition of Akt activation and glucose uptake. Methods: Eight ovarian cancer cell lines were incubated with media containing glucose, genistein, or 2-deoxyglucose (2-DOG) in the presence or absence of zVAD (a generalized caspase inhibitor). Growth inhibition was determined using the sulforhodamine assay. Viability and apoptotic fraction were determined by propidium iodide permeability and sub Go analysis respectively. Caspase and Akt activation were determined by immunoblotting. Glucose uptake was analyzed with the 3H-2-DOG assay. Morphology was determined by light microscopy and transmission electron microscopy. Autophagic vacuoles were visualized using monodansylcadaverine staining. Results: Genistein induced cell death in all eight ovarian cancer cell lines tested. Although genistein induced cell death in 50% of cells by 24 h, only 20% of cell death could be attributed to apoptosis as determined by PI permeability and SubGo analysis. Moreover, genistein induced cell death in the presence or absence of zVAD. Caspase-9 activation was seen following 48 h of treatment. Genistein treatment resulted in inhibition of glucose uptake and inhibition of Akt activation by 8 hours of treatment. Morphology was consistent with autophagic cell death. Conclusions: Constitutive activation of Akt confers resistance to chemotherapy induced apoptosis, and enhances aerobic glycolysis in ovarian cancer cells. We have shown that genistein inhibits Akt activation and glycolysis, and can induce both apoptotic and autophagic cell death in ovarian cancer cells. Most conventional chemotherapeutic agents induce apoptotic cell death. Because genistein can circumvent chemoresistance due to alterations in apoptotic signaling, it has the potential to be effective against chemoresistant disease.
Detectability Affects The Performance of Survey Methods - A Comparison of Sampling Methods of Freshwater Mussels in Central Texas

Designing effective surveys for freshwater mussels (Unionidae) is a challenge, because they are spatially clustered and often found in low densities. The objective of this study was to examine how the performance (in respect to species richness, the total number of mussels per search effort, species composition and size distribution) of three different survey methods (timed searches, transect method, and adaptive cluster method) varied between different habitats at six sites in rivers of Central Texas. Habitat conditions affected the performance of search methods by either facilitating or hindering the detection of mussels, e.g., sandy substrate facilitating the detection of mussels seemed to enhance the performance of the adaptive cluster method in respect to the number of mussels found per unit search effort. Differences in detectability of mussels was also associated with the size of mussels, their behavior and morphology. Timed searches detected a larger proportion of larger mussels that tended to be less burrowed and that had shells with more sculpturing compared to quantitative methods. Our results suggest that to design effective surveys variation in detectability of mussels must be considered which depends on local habitat conditions, experience of surveyor, behavior, size and morphology of mussels.
Creativity and the Big Two model of personality: plasticity and stability

The general conclusion from recent research on the Big Two dimensions of human personality — Plasticity (extraversion and openness) and Stability (neuroticism, agreeableness, and conscientiousness) — show that Plasticity has a more robust and stronger association with creativity than Stability. More specifically, people who are high in plasticity and low in stability may be most likely to exhibit creative thought and behavior. Moreover, current research in neuroscience, genetics and neurochemistry of behavior each suggest biological mechanisms for how these personality qualities lower thresholds for creative thought and behavior.
Hemicellulose-Cellulose Composites Reveal Differences in Cellulose Organization after Dilute Acid Pretreatment.

Model hemicellulose–cellulose composites that mimic plant cell wall polymer interactions were prepared by synthesizing deuterated bacterial cellulose in the presence of glucomannan or xyloglucan. D...
Enhanced properties of tungsten films by high-power impulse magnetron sputtering

Abstract Tungsten films (750–1200 nm thick) deposited by high-power impulse magnetron sputtering (HiPIMS) under various sputtering gas pressure and substrate bias are investigated for their physical and microstructural characteristics. Compared to films deposited by the traditional direct current (DC) method with the same deposition configuration and similar parameters, HiPIMS materials exhibit higher hardness, a smoother surface, and better adhesion to a substrate. These excellent properties are attributed to the highly uniform grain structures developed during HiPIMS deposition, in contrast to the funnel shaped grains seen in DC sputtered films. Combined with the in-situ stress measurements, we discuss the underlying mechanisms that lead to enhanced properties of HiPIMS tungsten films.
Intergenerational Effects of Dietary Restriction and Insulin/IGF Signaling on Starvation Resistance and Reproductive Development

The roundworm C. elegans reversibly arrests larval development during starvation, but extended early-life starvation reduces reproductive success. Maternal dietary restriction (DR) buffers progeny from starvation as young larvae, preserving reproductive success. However, the developmental basis of reduced fertility following early-life starvation is unknown, and it is unclear how maternal diet modifies developmental physiology in progeny. We show here that extended starvation in first-stage (L1) larvae followed by unrestricted feeding results in a variety of developmental abnormalities in the reproductive system, including glp-1/Notch-sensitive germ-cell tumors and uterine masses that express neuronal and epidermal cell-fate markers. We found that maternal DR and reduced maternal insulin/IGF signaling (IIS) increase oocyte provisioning of vitellogenin lipoprotein, reducing penetrance of starvation-induced abnormalities in progeny, including tumors. Furthermore, we show that maternal DR reduces IIS in progeny, and that daf-16/FoxO and skn-1/Nrf, transcriptional effectors of IIS, are required in progeny for maternal DR to suppress starvation-induced abnormalities. daf-16/FoxO activity in somatic tissues is sufficient to suppress starvation-induced abnormalities, suggesting cell-nonautonomous regulation of reproductive system development. This work reveals that early-life starvation compromises reproductive development and that intergenerational insulin/IGF-to-insulin/IGF signaling mediates adaptation to nutrient availability.
Prospect of Thermal Shock Induced Healing of Lithium Dendrite

Dendritic growth plagues the development of rechargeable lithium metal anodes. Recently, it has been reported that ( Science 2018, 359, 1513−1516) self-heating of the cell provides a mitigation strategy for suppressing dendrites. In order to study this phenomenon, we extend our recently developed nonlinear phase-field model to incorporate an energy balance equation allowing a full thermally coupled electrodeposition model using the open-source software package MOOSE. In this work, we consider the interplay between ionic transport and electrochemical reaction rate as a function of temperature and explore the possibility of using thermal shock induced dendrite suppression. We discover that, depending on the electrochemical reaction barrier and ionic diffusion barrier, self-heating could accelerate (larger reaction barrier) or decelerate (larger diffusion barrier) dendrite formation. Given that the electrolyte constituents can be used to tune both barriers, this study could provide an important avenue to exp...
Architecture interoperability and repeatability with microservices: an industry perspective

Microservices, along with supporting technologies such as containers, have become a prevalent architecture approach for today's software systems, especially in enterprise environments. They represent the latest evolutionary step in the decades-old journey towards service- and component-based software architectures. Along with virtualization technologies, microservices have enabled the loose-coupling of both service interfaces (message passing) and service integration (form and fit). This paper attempts to explore the impact of microservices on software architecture interoperability and repeatability, based on our experiences in developing two microservice-based systems. Our central thesis is that, if we view software architecture as a set of principal design decisions, the microservices approach enable us to more elegantly separate these decisions from non-architectural, domain-specific ones, and thus make these decisions more interoperable, reusable, and repeatable across disparate problem domains. We therefore propose that a microservices based reference architecture (RA) and reference implementation (RI) be created for the community-wide infrastructure for software engineering and software architecture research, along with a set of detailed considerations.
The effect of pollution on crime: Evidence from data on particulate matter and ozone

Abstract We estimate the effect of short-term air pollution exposure (PM2.5 and ozone) on several categories of crime, with a particular emphasis on aggressive behavior. To identify this relationship, we combine detailed daily data on crime, air pollution, and weather for an eight-year period across the United States. Our primary identification strategy employs extremely high dimensional fixed effects and we perform a series of robustness checks to address confounding variation between temperature and air pollution. We find a robust positive effect of increased air pollution on violent crimes, and specifically assaults, but no relationship between increases in air pollution and property crimes. The effects are present in and out of the home, at levels well below Ambient Air Pollution Standards, and PM2.5 effects are strongest at lower temperatures. The results suggest that a 10% reduction in daily PM2.5 and ozone could save $1.4 billion in crime costs per year, a previously overlooked cost associated with pollution.
Oxidative Stress and Redox Modifications in Nanomaterial–Cellular Interactions

The rapidly increasing development of engineered nanomaterials (ENMs) for multiple industries and societal applications has raised concern over the increased potential for human exposures. While knowledge gaps still exist regarding the fundamental mechanisms by which biological systems interact with and respond to various ENMs, it is now well established that many ENMs stimulate reactive oxygen species (ROS), either through direct redox chemistry or indirectly by modulating endogenous cellular metabolism. Indeed, many of the reported adverse biological responses to ENMs, such as the activation of antioxidant defense systems, inflammation, endoplasmic reticulum (ER) stress responses, and cell death, involve oxidative stress as a key event. Here, we summarize recent findings that support the central role of oxidative stress in ENM–cellular interactions, with an emphasis on phagocytic cells as an important target immune cell type. Emerging evidence enabled by new proteomics-based technologies indicates that redox-mediated cellular response pathways triggered by many ENMs may be initiated through the selective formation of protein redox modifications. The postulated role of protein redox modifications as molecular initiating events represents a novel conceptual framework for understanding specificity in ENM-induced oxidative stress responses and for discerning differences between cellular adaptive signaling and early toxicity.
Sequence and Evolution of Bovine MHC Class I Genes

Bovine MHC class I cDNAs were cloned and sequenced from PBLs of a MHC class I heterozygous bull (serotype w2, w30). Multiple copies of four unique cDNAs were sequenced. These four cDNAs were separated into two groups based upon sequence comparisons. Each of the groups appear to represent alleles of two different loci. Comparisons of these bovine sequences with published sequences from other artiodactyls demonstrates that one of the bovine MHC class I genes shares more sequence similarity with a sheep MHC class I sequence than with the other bovine MHC class sequences. These data suggest that concerted evolution of bovine and bovine MHC class I genes either has not occurred, or has not occurred at a rate sufficient to cause extensive sequence divergence between the MHC class I loci of cattle and sheep.
ICS: Incremental Constrained Smoothing for State Estimation

A robot operating in the world constantly receives information about its environment in the form of new measurements at every time step. Smoothing-based estimation methods seek to optimize for the most likely robot state estimate using all measurements up till the current time step. Existing methods solve for this smoothing objective efficiently by framing the problem as that of incremental unconstrained optimization. However, in many cases observed measurements and knowledge of the environment is better modeled as hard constraints derived from real-world physics or dynamics. A key challenge is that the new optimality conditions introduced by the hard constraints break the matrix structure needed for incremental factorization in these incremental optimization methods.Our key insight is that if we leverage primal-dual methods, we can recover a matrix structure amenable to incremental factorization. We propose a framework ICS that combines a primal-dual method like the Augmented Lagrangian with an incremental Gauss Newton approach that reuses previously computed matrix factorizations. We evaluate ICS on a set of simulated and real-world problems involving equality constraints like object contact and inequality constraints like collision avoidance.
Menstrual cycle effects on cardiovascular drift and maximal oxygen uptake during exercise heat stress.

Compared to other modulators of physiological strain associated with exercise heat stress, hyperthermia results in the greatest magnitude of cardiovascular (CV) drift and associated decrements in maximal oxygen uptake ( $$\dot{V}{\text{O}}_{2\max }$$ ). To determine if elevated core temperature in the luteal phase (LP) of the menstrual cycle results in greater CV drift and reductions in $$\dot{V}{\text{O}}_{2\max }$$ versus the follicular phase (FP). Seven women performed 15- and 45-min cycling bouts on separate occasions (60% $$\dot{V}{\text{O}}_{2\max }$$ , 35 °C) followed by a $$\dot{V}{\text{O}}_{2\max }$$ test during the FP and LP. CV drift was measured between 15 and 45 min during the 45-min bout, and the 15-min bout was for measuring $$\dot{V}{\text{O}}_{2\max }$$ over the same time interval that CV drift occurred. Core temperature during LP was ~ 0.3 °C higher than FP (P 0.05). Heart rate increased significantly over time but was not different between phases (P = 0.78). Stroke volume decreased more over time during LP compared to FP (P = 0.02), but the values were similar at the end of exercise between phases (both time points P > 0.05). $$\dot{V}{\text{O}}_{2\max }$$ decrements for FP (13%) and LP (16%) were also comparable (P = 0.97). The LP–FP difference in core temperature in this study was not sufficient to amplify CV strain and decrements in $$\dot{V}{\text{O}}_{2\max }$$ . Greater differences in core temperature may be required to independently modulate CV drift and accompanying decrements in $$\dot{V}{\text{O}}_{2\max }$$ during prolonged exercise heat stress.
Human-Mediated Land Use Change Drives Intraspecific Plant Trait Variation

In the Anthropocene, more than three quarters of ice-free land has experienced some form of human-driven habitat modification, with agriculture dominating 40% of the Earth's surface. This land use change alters the quality, availability, and configuration of habitat resources, affecting the community composition of plants and insects, as well as their interactions with each other. Landscapes dominated by agriculture are known to support a lower abundance and diversity of pollinators and frequently larger populations of key herbivore pests. In turn, insect communities subsidized by agriculture may spill into remaining natural habitats with consequences for wild plants persisting in (semi) natural habitats. Adaptive responses by wild plants may allow them to persist in highly modified landscapes; yet how landscape-mediated variation in insect communities affects wild plant traits related to reproduction and defense remains largely unknown. We synthesize the evidence for plant trait changes across land use gradients and propose potential mechanisms by which landscape-mediated changes in insect communities may be driving these trait changes. Further, we present results from a common garden experiment on three wild Brassica species demonstrating variation in both defensive and reproductive traits along an agricultural land use gradient. Our framework illustrates the potential for plant adaptation under land use change and predicts how defense and reproduction trait expression may shift in low diversity landscapes. We highlight areas of future research into plant population and community effects of land use change.
Proof-of-Travel: A Protocol for Trustworthy V2I Communication and Incentive Designs

Previous work on misbehavior detection and trust management can identify falsified and malicious Vehicle-to-Everything (V2X) messages and enable witness vehicles to report their observations to the trust authority for certificate management. However, there may not exist enough “benign” vehicles with V2X connectivity or vehicle owners who are willing to opt-in at an early stage of connected vehicle deployment. In this paper, we propose a security protocol for Vehicle-to-Infrastructure (V2I) communication, titled Proof-of- Travel (POT), to answer the research question: How can we transform the power of cryptography techniques embedded within the protocol into social and economic mechanisms to simultaneously incentivize V2X adoption and determine the trustworthiness of V2I data? The POT protocol determines the trust of a vehicle based on its distance traveled and the V2I information the vehicle has shared along the path of its movement. Additionally, the total vehicle mileage traveled by the vehicle must be testified by the digital signatures from infrastructure components in the vehicle's trajectory. Targeting rationale attackers motivated by profit-seeking behaviors, the POT protocol creates burdens for malicious vehicles who must acquire chains of proofs for compulsory spatial movement to gain reputation. However, the protocol does not incur extra cost for a normal vehicle who naturally moves from the origin to the destination. Instead, the verifiable vehicle mileage traveled by the normal vehicle can be used to determine its contributions and stake in the system as the altruistic behaviors of sharing observations about traffic events can benefit the transportation network. We show how to use the POT protocol to construct voting-based consensus algorithms to decide the authenticity and the correctness of vehicle-reported events and present initial simulation results.
Finite element modeling of direct metal laser solidification process: Sensor data replication and use in defect detection and data reduction via machine learning

Abstract In the additive manufacturing (AM) industry, the direct metal laser solidification (DMLS) process has received significant research interest because of its ultra-high precision and geometry variability. However, many possible process errors can happen during the printing process and in-situ quality control is quite challenging because of the lack of appropriate monitoring and analysis capabilities. Thus, in this work, a part-scale finite element method (FEM) model is developed to investigate the heat transfer behavior of the DMLS process and to extract experimentally relevant thermal features. Specifically, a microscopic and a mesoscale sub-model are initially developed to describe powder properties and the laser behaviors, respectively, and their outputs are directly incorporated in the part-scale FEM model. The FEM model-generated data are then processed to replicate the long-wave infrared (LWIR) camera sensor outputs. Finally, both the experimental and FEM model-generated images are used to train machine learning algorithms for in-situ defect detection applications. In addition, we are endeavoring to look into a convolutional neural network utilizing such realistic thermal features from LWIR images with and without a variety of simulated data augmentation to examine its contribution to the CNN training. The thermal feature extraction and the machine learning algorithm are then utilized for the data reduction purpose. Also, a transmission strategy is demonstrated to filter out a significant amount of redundant data while maintaining high model prediction quality.
Blended Instruction in Symbolic Logic

This study examines through action research whether blended instruction in an upper-level philosophy course in introductory symbolic logic can help undergraduate philosophy students to achieve better learning outcomes than undergraduate philosophy students in a traditional, face-to-face version of the same course. The authors conclude that the change from traditional instruction to blended instruction did have a positive and significant effect on student learning as measured in course grades and student assessment scores for one course learning objective, as well as a positive but non-significant effect on student assessment scores for two additional course learning objectives.
Antibody Response to 2-Dose SARS-CoV-2 mRNA Vaccination in Pediatric Solid Organ Transplant Recipients.

While many adult solid organ transplant recipients (SOTRs) have impaired antibody response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination, pediatric SOTRs' response has not been assessed.1-2 We report the immunogenicity and safety of BNT162b2 mRNA vaccination in pediatric SOTRs.
Event Related Potential Assessment of Sensory and Cognitive Deficits in the Mentally Retarded

The application of event related potential (ERP) techniques to the mentally retarded presents a somewhat different challenge to the electrophysiologist than does the application of ERPs to other clinical populations. In particular, while differential diagnosis is of major interest in the investigation of such problems as minimal brain damage (MBD), schizophrenia and dementia, diagnosis is of less importance in mental retardation. What is important is to differentiate among the different types of information processing deficits occurring in the retarded so that educational remediation may be designed on an individual basis to compensate for sensory and intellectual inadequacies.
Development of a Human Bone Marrow Progenitor Cell Line to Examine HIV-1 Susceptibility and LTR Activity

Previous studies have suggested that the bone marrow compartment may play an integral role in the genesis of HIV-1 dementia (HIVD). Interestingly, CD34+/CD38pluripotent stem cells within the bone marrow are refractile to HIV-1 infection. The CD34+/CD38+ TF-1 cell line has been selected as a model to study HIV-1 infection during the differentiation process of hematopoietic progenitor cells. A number of cytokines such as GM-CSF, M-CSF, IL-1β, TNF-α, and IL-4 were used to induce differentiation and activation of TF-1 cells and their surface marker expression was monitored by flow cytometry. Interestingly, IL-1β treatment, alone or in combination with TNFα, lead to up-regulation of CXCR4 and CCR5 surface presentation, and preservation of CD4 expression possibly providing an optimal cellular phenotype for HIV-1 infection of this cell population. The surface marker expression after this treatment also correlated with a more differentiated phenotype. To begin exploring the potential of these cells to support productive HIV-1 replication, a series of stably transfected cell lines were developed. To this end, macrophage-, T celland dual-tropic long terminal repeats (LTRs) were coupled to the gene encoding green fluorescent protein. These cell lines were utilized to explore the functional properties of specific cis-acting regulatory elements in LTR function within the bone marrow precursor cell population. from 2005 International Meeting of The Institute of Human Virology Baltimore, USA, 29 August – 2 September 2005
Abstract 916: A multidimensional analysis of predictive biomarkers in colorectal cancer

Background: CRC cancer is one of the deadliest diseases in Western countries. In order to develop predictive biomarkers for CRC (colorectal cancer) aggressiveness, we analyzed retrospectively 267 CRC patients via a novel, multidimensional biomarker platform. Methods: Using nanofluidic technology for qPCR analysis and quantitative fluorescent immunohistochemistry for protein analysis, we assessed 33 microRNAs, 124 mRNAs and 9 protein antigens. Analysis was conducted in each single dimension (microRNA, gene or protein) using both the multivariate Cox model and Kaplan-Meier method. Thereafter, we simplified the censored survival data into binary response data (aggressive vs. non aggressive cancer). Subsequently, we combined the data into multidimensional scores using inverse sliced regression for sufficient dimension reduction. Accuracy was assessed using the Area under the Curve (AUC) and the receiver operating characteristic (ROC) method. Results: Single dimension analysis led to the discovery of individual factors that were significant predictors of outcome. These included seven specific microRNAs, four genes, and one protein. When these factors were quantified individually as predictors of aggressive disease, the highest demonstrable area under the curve (AUC) was 0.68. By contrast, when all results from single dimensions were combined into multidimensional biomarkers, AUCs were dramatically increased with values approaching and even exceeding 0.9. Conclusions: Single dimension analysis generates statistically significant predictors, but their predictive strengths are suboptimal for clinical utility. A novel, multidimensional approach overcomes these deficiencies. Newly derived multidimensional biomarkers have the potential to meaningfully guide the selection of therapeutic agents for individual patients while elucidating molecular mechanisms driving disease progression. Citation Format: Marisa Mariani, Shiquan He, Mark McHugh, Mirko Andreoli, Deep Pandya, Steven Sieber, Zheyang Wu, Paul Fiedler, Shohreh Shahabi, Cristiano Ferlini. A multidimensional analysis of predictive biomarkers in colorectal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 916. doi:10.1158/1538-7445.AM2014-916
The OAO heat pipes - 8 1/2 years of flight data

Heat pipe performance data taken during the 8 1/2 years of flight of the OAO-C (Copernicus) spacecraft are presented. Three fixed conductance heat pipes (FCHP), each with different wicking concepts (axial groove, pedestal artery, and self-priming spiral artery), and one variable conductance heat pipe (VCHP) are onboard. Aluminum tubes (1/2 in. diameter) rolled into a 48 in. loop containing ultra high purity ammonia as the heat transfer fluid comprise all FCHP, whose purpose is to circumferentially isothermalize the central tube housing the telescope. The VCHP is a hot, non-wicked reservoir concept including a composite artery and methanol heat transfer fluid, and is used to maintain the temperature of the onboard processor. Flight thermal data analysis reveals that no degradation in performance occurred since launch and agrees well with pre-flight data; the onboard processor still shows an offset in control range of 4 F, and the pipes perform the same after 8 1/2 years in orbit.
Matrices in the Theory of Signed Simple Graphs

I discuss the work of many authors on various matrices used to study signed graphs, concentrating on adjacency and incidence matrices and the closely related topics of Kirchhoff (`Laplacian') matrices, line graphs, and very strong regularity.
Estimation of a Nonlinear Panel Data Model with Predetermined Variables and Semiparametric Individual Effects

In this paper, we explore identification and efficient semipa rametric estimation of a class of nonlinear panel data index models with small-T, which includes a class of single-index panel discrete-choice models. The model allows for the inclusion of predetermined variables, lagged dependent variables, and a nonparametric specification of the individual-specific effects. The paper provides a root- N consistent, asymptotically normal and efficient estimator for the finite-dimensional pa rameters, and a consistent estimator of the unknown index function. The estimator developed in this paper may be computed with any smoother, be it sieves or kernel smoothers. We propose a powerful new kernel-based modified backfitting algorithm to com pute the estimator. The algorithm fully implements the identifying restrictions o f the model. We study the small sample properties of the estimator via Monte Carlo techniques. The results indicate that the estimator performs well in recovering the finit e dimensional parameters of interest. The simulation results also show that, in small sa mples, the estimator outperforms more parametric models with various mis-specificatio ns of the index function.
Exon Shuffling by L1 Retrotransposition

Long interspersed nuclear elements (LINE-1s or L1s) are the most abundant retrotransposons in the human genome, and they serve as major sources of reverse transcriptase activity. Engineered L1s retrotranspose at high frequency in cultured human cells. Here it is shown that L1s insert into transcribed genes and retrotranspose sequences derived from their 3' flanks to new genomic locations. Thus, retrotransposition-competent L1s provide a vehicle to mobilize non-L1 sequences, such as exons or promoters, into existing genes and may represent a general mechanism for the evolution of new genes.
Morphology: from sharp interface to phase field models

Abstract Over the last 50 years, there has been tremendous progress in the quantification of crystal growth morphology. In the 1950s, the dynamics of crystal growth from the melt was based on the sharp interface model (interface of zero thickness separating solid and liquid), often under the assumption of isotropy. Ivantsov had discovered analytical solutions to the Stefan problem for the special class of shapes known as quadric surfaces (ellipsoids, hyperboloids and paraboloids, including their special cases spheres, cylinders and planes). But in the 1960s, these solutions were shown to be morphologically unstable, resulting in cellular and dendritic growth forms that had long been known to exist from experimental work. Sharp interface models were used to model these growth forms, but it was necessary to include corrections of the interface temperature for capillarity and curvature (Gibbs–Thomson equation) in order to avoid instabilities at all wavelengths and to set the size scale of the resulting morphologies. Except for the case of total interface control, for which exact solutions even for facetted crystals had been provided by Frank using the method of characteristics, little could be done analytically to treat anisotropies. By the 1980s, our reliance on the sharp interface model began to change with the adaptation by Langer and others of diffuse interface models, of the Cahn–Hilliard type, to solve dynamical problems. This class of models, now known as phase field models, replaced the sharp interface model by the solution in the entire computational domain of coupled partial differential equations for thermal and compositional fields and for an auxiliary variable that keeps track of the phase. Moreover, the phase field equations incorporate automatically the Gibbs Thomson equation, anisotropy and even departures from local equilibrium (interface kinetics) asymptotically for a sufficiently thin diffuse interface. But it has been only in about the last decade that massive improvements in computing power have rendered the numerical solution of the phase field model tractable. By means of this model, complex morphologies and related phenomena over a vast range of length scales can now be studied.
Discharge Coefficient and Effectiveness Measurement for Conical Shaped Film Cooling Holes

Experimental measurements of discharge coefficient and effectiveness of conical shaped film cooling holes with 1°, 2° and 3° uniform diffusion angle are presented. All film holes are inclined at 35° with hole length to diameter ratio, L/D = 3.5, pitch to diameter ratio, PI/D = 3 with a constant density ratio of 1.26 and with nitrogen as the coolant. Results show that conical film holes have higher discharge coefficients than their cylindrical counterparts. For conical holes, the local distribution and laterally averaged effectiveness values decrease with increasing blowing ratio from 0.45 to 1. The configuration with 3° uniform diffusion angle has the highest effectiveness values and outperforms the conical holes with 1°, 2° diffusion angles by 40% in the proximity of the holes (X/D ≪ 5) at a blowing ratio of 0.45. Results are compared to base line cylindrical as well as to fan shape film holes available in open literature. The average effectiveness of the conical holes can reach values comparable to those achieved by fan shaped film holes at the same blowing ratio.Copyright © 2005 by ASME
Approximating the connectivity between nodes when simulating large-scale mobile ad hoc radio networks

Simulation is a widely used technique in the design and evaluation of mobile ad hoc networks. However, time and space constraints can often limit the extent of the size, complexity and detail of the networks that can be simulated. Approximations in the system model can possibly alleviate this problem, but we need to be careful about how much accuracy is compromised when employing them.This paper specifically focuses on one aspect of simulation cost that is incurred in the computation of the connectivity graph that is used to describe what mobile nodes can communicate with whom. Since such a graph is re-computed frequently during the simulation, we explore alternatives to computing this graph exactly and their accuracy in capturing the actual graph properties.We investigate three approximation alternatives to compute graph connectivity, and propose metrics for expressing their deviations from the actual graph. In addition, the graphs generated by these approximations are compared to the original by examining several previously proposed graph measures--the degree distribution, clustering coefficient, shortest path distribution and eigenvalue distribution. Such comparisons are conducted not only with static graphs, but also with dynamically changing graphs that are a consequence of clients moving. Results indicate that these approximations can be quite effective in avoiding repeated calculation of exact graph connectivity.
FINGER: A Symbolic System for Automatic Generation of Numerical Programs in Finite Element Analysis

FINGER is a LISP-based system to derive formulas needed in finite element analysis, and to generate FORTRAN code from these formulas. The generated programs can be used with existing, FORTRAN-based finite element analysis packages. This approach aims to replace tedious hand computations that are time consuming and error prone. The design and implementation of FINGER are presented. Techniques for generating efficient code are discussed. These include automatic intermediate expression labelling, interleaving formula derivation with code generation, exploiting symmetry through generated functions and subroutines. Current capabilities include generation of material matrices, strain-displacement matrices and stiffness matrices. FINGER contains a package, called GENTRAN, that translates symbolic formulas into FORTRAN. GENTRAN can generate functions, subroutines and entire programs. Thus, it is also of interest as a general-purpose FORTRAN code generator, Aside from the finite element application, the techniques developed and employed are useful for automatic code generation in general.
Using low-stakes quizzing for student self-evaluation of readiness for exams

Introductory level courses in many Science, Technology, Engineering, and Math (STEM) disciplines require students to acquire an enormous new discipline-specific vocabulary in preparation for future courses. Students are often not prepared for the amount of self-directed studying they must do to be successful in these types of courses, particularly in their first year of college. To assist students in more accurately gauging their readiness for an exam, online low-stakes quizzes were implemented in a freshman level course, giving students an opportunity to practice their new language with minimal grade-related consequences. This quizzing strategy provides students an opportunity to self-assess their current level of knowledge. The quizzes also provide feedback, helping students determine how to adjust their behavior to ensure that acquisition of the missing knowledge is successful. This paper presents preliminary results of the research effort and illustrates the effects of this low-stakes quizzing. Specifically, this paper evaluates (1) whether the quizzing helps students to better prepare for medium and high stakes exams; (2) whether the quizzing increases the mean exam scores compared to previous semesters with no quizzing; and (3) whether the quizzing must be required (low-stakes) to be effective, or whether it can be optional (no-stakes) and still benefit students.
Discriminating among the discriminator bases of tRNAs

Aminoacyl-tRNA synthetases must select their specific tRNAs from the 20 structurally similar tRNAs present in a cell. The discriminator base, at position 73 of the tRNA, is important for this selection but its effects on aminoacylation are variable depending on context. Recent structural studies provide insight into this variability.
LIM kinase 1 accumulates in presynaptic terminals during synapse maturation

LIM kinase 1 (LIMK1) is a cytoplasmic protein kinase that is highly expressed in neurons. In transfected cells, LIMK1 binds to the cytoplasmic tail of neuregulins and regulates the breakdown of actin filaments. To identify potential functions of LIMK1 in vivo, we have determined the subcellular distribution of LIMK1 protein within neurons of the rat by using immunomicroscopy. At neuromuscular synapses in the adult hindlimb, LIMK1 was concentrated in the presynaptic terminal. However, little LIMK1 immunoreactivity was detected at neuromuscular synapses before the 2nd week after birth, and most motoneuron terminals were not strongly LIMK1 immunoreactive until the 3rd week after birth. Thus, LIMK1 accumulation at neuromuscular synapses coincided with their maturation. In contrast, SV2, like many other presynaptic terminal proteins, can be readily detected at neuromuscular synapses in the embryo. Similar to its late accumulation at developing synapses, LIMK1 accumulation at regenerating neuromuscular synapses occurred long after these synapses first formed. In the adult ventral spinal cord, LIMK1 was concentrated in a subset of presynaptic terminals. LIMK1 gradually accumulated at spinal cord synapses postnatally, reaching adult levels only after P14. This study is the first to implicate LIMK1 in the function of presynaptic terminals. The concentration of LIMK1 in adult, but not nascent, presynaptic terminals suggests a role for this kinase in regulating the structural or functional characteristics of mature synapses. J. Comp. Neurol. 416:319–334, 2000. © 2000 Wiley-Liss, Inc.
Cellular therapy and induced neuronal replacement for Huntington's disease.

Huntington’s disease (HD) is an inherited, relentlessly progressive neurodegenerative disease with an invariably fatal outcome. HD is inherited in an autosomal dominant fashion, and is characterized pathologically by the loss of cortical and striatal neurons, and clinically by involuntary choreiform movements accompanied by progressive cognitive impairment and emotional lability. The disorder is caused by an expanded cystosine adenine guanine (CAG) tri-nucleotide repeat encoding polyglutamine (polyQ) in the first exon of the Huntingtin gene. There is a correlation between the number of CAG repeats and disease onset, such that in patients with CAG repeat lengths of 36 to 60, disease symptoms typically manifest after 35 years of age, whereas CAG repeat lengths >60 yield the more severe juvenile form of the disease. Even though mutant huntingtin is expressed throughout the brain, it is characterized by the selective degeneration of medium spiny neurons of the caudate and putamen, which heralds more widespread neuronal degeneration with disease progression. The mechanisms of cell dysfunction and death in HD have been the subjects of a number of studies, which have led to therapeutic strategies largely based on the amelioration of mutant huntingtin-related metabolic impairment and cellular toxicity. Each of these approaches has aimed to delay or stop the preferential degeneration of medium spiny neurons early in the disease course. Yet, in later stages of the disease, after cell death has become prominent, cell replacement therapy (whether by direct cell transplantation or by the mobilization of endogenous progenitors) may comprise a stronger potential avenue for therapy. In this review, we will consider recent progress in the transplantation of fetal striatal cells to the HD brain, as well as emerging alternative sources for human striatal progenitor cells. We will then consider the potential application of gene therapy toward the induction of striatal neurogenesis and neuronal recruitment, with an eye toward its potential therapeutic use in HD.
Traumatic emphysema of the face and neck associated with a midfacial fracture.

Abstract The incidence, treatment, and prognosis of traumatic emphysema following a midface fracture have been presented.
Parameter estimation for a global model of terrestrial biogeochemical cycling by an iterative method

Abstract We have implemented a geographically distributed ecosystem model TERRA for the carbon, nitrogen, and water dynamics of the global terrestrial biosphere. The ecosystem model in each grid cell has state variables of soil water; vegetation carbon, soil carbon, vegetation nitrogen, soil organic nitrogen, soil inorganic nitrogen, and a variable for allocation. Eight parameters associated with eight carbon or nitrogen fluxes are determined during model calibration at specific sites for each of 17 vegetation types that cover the globe. Calibration is performed by an iterative method that brings calculated fluxes into agreement with observed fluxes over successive iterations. For the 17 vegetation types, calibration required a geometric mean number of 123 iterations for convergence with a geometric S.D. of 2.25. The minimum and maximum iterations required was 52 and 1060 for xeromorphic woodland and tropical evergreen forest, respectively. The parameter controlling gross primary productivity Cmax was found to be correlated with maximum projected leaf area index (plus cover of nonvascular plants) with a correlation coefficient of 0.90 (r2=0.81). Correlation of parameters with the input fluxes and average standing crops corresponding to the iteration equation was high in those cases in which temperature and precipitation were not explicit factors in the iteration equation. The parameters Kfall, Lnc, and Nloss had correlation coefficients of 1.0 each with the appropriate ratio of the matching observed transfer flux and standing crop. In iteration equations with explicit dependence on temperature, soil moisture, and other factors, the correlation coefficients were less than 1.0 with these ratios; the parameters Cmax, Kr, Kd, Nmax, and Nup had correlation coefficients of 0.83, 0.66, 0.60, 0.61, and 0.87, respectively. These correlation coefficients indicate the importance of environmental factors such as temperature and soil moisture in the calibration process and the robustness of the iteration method in determining parameters in systems with time-varying coefficients.