cssi/SciSciGPT-SciSciNet huggingface dataset:
Nanomembrane Hybrid Electronics for Wireless Detection of Sourness and Saltiness Toward an Artificial Taste System

Quantification of nutrient intake is critical to health management and controlling eating behavior. Recent advances in nanotechnology and miniaturized electronics enable the development of wearable and implantable devices for a range of health monitoring and disease diagnostics. Such low-profile, hybrid devices may be applied to unique applications in the oral cavity. An inserted oral electronic device with an array of sensors can detect various ions in food; acting as an artificial taste system. Existing systems serving this purpose require plastic circuit boards and rigid sensors, which is far from ideal as it causes user discomfort in a mechanically -and thermally-sensitive intraoral environment. Here, we introduce a nanomembrane-based stretchable, active hybrid electronic system with integrated sensors for detection of sourness and saltiness, capable of long-range wireless telemetry. The matrix of nanostructured circuit interconnects and strain-isolated blocks for functional chip integration offers unobtrusive integration of the circuit with mechanical bendability (> 180 degrees) and stretchability (> 30 %) on a breathable porous membrane. An array of electrochemical sensors enables selective detection of pH and sodium for determination of sourness and saltiness, with the aim of designing a full artificial taste system. Computational modeling and experimental study establish a mechanics modeling tool for a stretchable circuit that integrates functional chip components. Analytical calculation designs reliable wireless circuitry for a stable, long-range communication with an external smart appliance. In vivo study with human subjects wearing the hybrid electronics on the palate demonstrates the device functionality for wireless quantification of hydrogen ion and sodium intake, which can be extended for an artificial taste system with greater sensing capability.
Cryopreservation and microfluidics: a focus on the oocyte

Cryopreservation of gametes and embryos has played a critical role in successful assisted reproductive technologies in rodents, domestic farm species, endangered species and humans. With improved success, and changing needs, the utility of gamete or embryo cryopreservation has escalated. In this review we address some of the foundational history of mammalian cryobiology, species-specific utilities, fundamental understandings of cryoprotectant agents and their use in slow-rate freezing and vitrification, and expand on the recent success and uses of oocyte vitrification and warming. In the area of female gamete cryopreservation, emphasis will be placed on not just cell survival, but also perceived and measured affects of cryopreservation on intracellular structures and functions that affect subsequent completion of meiosis with chromatin segregation fidelity, normal fertilisation and embryonic developmental competence. We compare and contrast data from cow, mouse and humans with a focus on using species-comparative developmental biology to guide future studies for improving methodologies for all species. The application of the relatively new technology microfluidics is discussed in relation to moving gradually (i.e. changing the solution over cells in an automated fashion) compared with the stepwise manual movement of cells through changing solution currently used. This use of microfluidics to change the way cells are exposed to cryoprotectant agents can provide new insights into the effects of osmotic stress and cellular strain rates previously unappreciated, precise methods of computational and biological data acquisition and appreciation of morphometric changes to cellular structure in response to different osmotic stresses and strain rates achieved with varying cryoprotectant exposures. Collectively, these devices and methodologies provide a means of achieving incremental improvement of oocyte and zygote cryopreservation with normalised and improved developmental competence. Finally, we look to the past and the future to acknowledge the accomplishment of leaders in the field of mammalian gamete and embryo cryobiology, their inspirational works, their tireless dissemination of information and the potential of new technologies in bioengineering to improve the efficiency and safety of gamete and embryo cryopreservation.
Normal Reference Values and Reproducibility of Tricuspid Annulus Dimensions Using Cardiovascular Magnetic Resonance

Tricuspid annular (TA) dilation is a key process in functional tricuspid regurgitation, but normal TA dimensions using cardiovascular magnetic resonance have not been established. We measured TA diameters in 66 healthy volunteers, aged 38 ± 11 years, during 3 different phases of the cardiac cycle (end-systole, early diastole, and end-diastole) and in 2 routinely acquired cardiovascular magnetic resonance imaging planes (4-chamber [4C] and right ventricular inflow-outflow [RVIO]). Three readers independently measured each value and 1 reader repeated measurements 1 month apart. The upper limit of normal (ULN) was calculated as 1.96 standard deviations above the mean. We assessed inter- and intraobserver reliability using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. We found the TA diameter largest during early diastole in the 4C view with an ULN of 43 mm (22 mm/m2). Men had larger absolute TA diameters (36 mm, 95% CI 27 to 44 mm) than women (30 mm, 95% CI 23 to 37 mm) but not after indexing for body surface area (both 18 mm/m2). In the RVIO view, the largest TA diameter occurred during early diastole with a ULN value of 46 mm (27 mm/m2). In this view, females had a larger indexed TA than men (21 mm/m2 vs 17 mm/m2). Reproducibility of measurements was excellent in all cardiac phases with an inter-rater ICC between 0.90 to 0.96 and an intrarater ICC 0.89 to 0.96. In conclusion, we have provided normative data regarding TA dimensions in routinely acquired 4C and RVIO views, and these values are larger than the current thresholds of annular dilation measured by echocardiography. Gender differences with the TA diameter in the RVIO view may be an important finding with consideration of future tricuspid devices.
Association between exposure to air pollution and hippocampal volume in adults in the UK Biobank

Abstract Background The hippocampus is important for memory processing. Several neuropsychiatric diseases including Alzheimer’s disease are associated with reduced hippocampal volume, and further the hippocampus appears vulnerable to environmental insult. Air pollution has been associated with cardiovascular disease, abnormal brain structure, and cognitive deficits. Objective Because of hippocampal vulnerability to environmental insults and based on the association between exposure to air pollution and cognitive function and brain structure, we evaluated the association between exposure to toxins in air pollution and left and right hippocampal volume using brain-imaging and air-pollution data from the UK Biobank, a large community-based dataset. Methods We used regression modelling to evaluate the association between exposure to nitrogen dioxide, nitrogen oxides, PM 2.5 , PM 2.5-10 , and PM 10. and left and right hippocampal volume controlling for age, sex, body-mass index, overall health, alcohol use, smoking, educational attainment, socioeconomic status, inverse distance from the nearest major road, and a measure of total brain volume. Results In these models, PM 2.5 concentration was associated with smaller left hippocampal volume. None of the other measures of air pollution was associated with either left or right hippocampal volume, although interaction models provided some evidence that sex might moderate the relationship between air pollution and hippocampal volume. In adjusted models, age, sex, educational attainment, income, overall health, current smoking, alcohol intake, and body-mass index were associated with hippocampal volume. Conclusions PM 2.5 at levels found in the United Kingdom was associated with smaller left hippocampal volume. Additional associations between several covariates and hippocampal volumes indicate that hippocampal volume might be associated with several potentially modifiable variables.
Serial-section electron microscopy using automated tape-collecting ultramicrotome (ATUM)

The Automated Tape-Collecting Ultramicrotome (ATUM) is a tape-reeling device that is placed in a water-filled diamond knife boat to collect serial sections as they are cut by a conventional ultramicrotome. The ATUM can collect thousands of sections of many different shapes and sizes, which are subsequently imaged by a scanning electron microscope. This method has been used for large-scale connectomics projects of mouse brain, and is well suited for other smaller-scale studies of tissues, cells, and organisms. Here, we describe basic procedures for preparing a block for ATUM sectioning, handling of the ATUM, tape preparation, post-treatment of sections, and considerations for mapping, imaging, and aligning the serial sections.
Illustrate: Software for Biomolecular Illustration

The small program Illustrate generates non-photorealistic images of biological molecules for use in dissemination, outreach, and education. The method has been used as part of the "Molecule of the Month," an ongoing educational column at the RCSB Protein Data Bank (http://rcsb.org). Insights from 20 years of application of the program are presented, and the program has been released both as open-source Fortran at GitHub and through an interactive web-based interface.
Josephson Junctions for Metrology Applications

The Josephson effect has revolutionized voltage metrology [1, 2, 3, 4, 5] and, together with the quantum Hall effect for resistance and atomic clocks for time and frequency, has enabled measurement standards based on quantum effects.
Less Experienced Telestroke Consultants Are More Likely to Go On-Camera, but Less Likely to Give tPA.

Background. Stroke telemedicine (telestroke) increases tPA availability and administration. However, the effective use of telestroke requires training, which is not a standard component of vascular neurology training. As a result, many providers learn telestroke skills “on the job” after finishing their training. Aims. We sought to explore if providers with more telestroke experience would be more efficient in the utilization of telemedicine, compared to providers with less experience. Methods. We prospectively collected data on telestrokes between July 2014 and July 2017 at a Comprehensive Stroke Center. Telestrokes are initiated on the telephone and typically, but not always, followed by an on-camera consult. Decision to do a phone-only versus on-camera consult is at the provider’s discretion. Results. There were 1,029 telestrokes, of which 807 were on-camera (74%). Of the 8 telestroke providers, 4 had less experience, having just finished stroke fellowship, and 4 had more experience (mean = 7.8 years of telestroke experience at the beginning of the study). Providers with less experience were more likely to go on camera than providers with more experience (79% vs. 67% of consults, ), but were less likely to give tPA when on-camera (25% vs. 33%, ). The absolute rate of tPA administration, combining phone and camera administration, or the frequency of technical difficulties were not different. Conclusions. Telestroke consultants with less experience do not triage as many cases by phone and are less likely to administer tPA on-camera, suggesting their use of telemedicine is not optimized. This supports the introduction of telestroke didactics during vascular neurology training.
Inpatient Pain Management in Patient with Opioid Use Disorder

The opioid epidemic has ushered in a high-risk patient population that all pain physicians will encounter in the inpatient setting. With the increased emphasis on pain as the “fifth vital sign” and a wider array of new opioids, the 1990s marks the beginning of a dramatic rise in opioid prescriptions. Opioid analgesics are the most commonly prescribed medication in the United States. Additionally, ten million people in the United States use opioid prescriptions for nonmedical reasons (Raub and Vettese, J Hosp Med 12:375–379, 2017). Chronic opioid users exhibit signs of tolerance to opioids while also having increased perception of pain. Acute pain management in these patients is best managed by a multimodal approach using medications such as ketamine, lidocaine infusions, dexmedetomidine and regional anesthetic techniques.
CMOS Integrated Impedance to Frequency Converter for Biomedical Applications

In this paper, we develop a CMOS integrated impedance to frequency converter for biological cell-electric substrate impedance sensing (ECIS). The design consists of low-power current comparators, SR-Latches for resistance to frequency, voltage comparators, an XOR gate, and an SR-Latch for capacitance to frequency conversion. Experimental results in a 180 nm process show a power consumption of 16 μW and area of 300 μm2. The resolution of the system is 0.8 Ω over a resistance range of 1 Ω to 10 kΩ. The extracted error is 0.4% for capacitance and 0.1% for resistance.
Acute care nurses’ attitudes toward nursing students with disabilities: A focused ethnography

Discrimination towards individuals with disabilities is problematic within nursing. There have been calls to increase diversity in nursing and this includes embracing nurses with disabilities. Increasing diversity in nursing requires increasing diversity among nursing students; in this way, nurse educators are gatekeepers to the profession. Clinical education is a crucial element of nursing education, yet there have been very few studies related to the clinical education of nursing students with disabilities. There have been no studies of attitudes of acute care nurse preceptors toward students with disabilities in the United States. This gap is important as the majority of clinical experiences occur in the acute care environment. Utilizing a focused ethnography, semi-structured interviews were conducted with 20 acute care nurses with at least two years' experience precepting students. While positive feelings about nursing students with disabilities were shared, thoughts and behavioral intentions remained negative. Six themes emerged: safety, barriers, otherness, communicating to meet needs, disclosure, and student versus colleague. Attitudinal barriers are the primary barriers faced by individuals with disabilities in becoming and practicing as nurses. Nurses in practice and education must embrace more inclusive attitudes towards individuals with disabilities.
Single-mode topological valley-Hall lasing controlled by the degree of asymmetry

Topology plays a fundamental role in contemporary physics and enables new information processing schemes and wave device physics with built-in robustness. However, the creation of photonic topological phases usually requires complex geometries that limit the prospect for miniaturization and integration, and, dispossess designers of additional degrees of freedom needed to control topological modes on-chip. By controlling the degree of asymmetry (DoA) in a photonic crystal with broken inversion symmetry, we report single-mode lasing of valley-Hall ring cavities at telecommunication wavelength. Our results open the door to novel optoelectronic devices and systems based on compact topological integrated circuits.
Identifying individuals with primary central nervous system tumors at risk for hereditary cancer syndromes using the Utah Population Database.

10532Background: CNS tumors are the most common solid tumors and the deadliest cancers in children. Approximately 10% of children with a CNS tumor harbor a hereditary cancer syndrome (HCS), but man...
STOICHIOMETRY OF THE SODIUM PUMP-PHOSPHOLEMMAN REGULATORY COMPLEX

The sodium-potassium ATPase (NKA) establishes ion gradients that facilitate many physiological processes. In the heart, NKA activity is regulated by its interaction with phospholemman (PLM, FXYD1). Here we used a novel fluorescence lifetime-based assay to investigate the structure, stoichiometry, and affinity of the NKA-PLM regulatory complex. We observed concentration dependent association of the subunits of NKA-PLM regulatory complex, with avid association of the alpha subunit with the essential beta subunit followed by lower affinity alpha-alpha and alpha-PLM interactions. The data provide the first evidence that the regulatory complex is composed of two alpha subunits associated with two beta subunits, decorated with two PLM regulatory subunits in intact cells. Docking and molecular dynamics simulations generated a structural model of the complex that is consistent with our experimental observations. We propose that alpha-alpha subunit interactions support conformational coupling of the catalytic subunits, which may enhance NKA turnover rate. These observations provide insight into the pathophysiology of heart failure, wherein low NKA expression may be insufficient to support formation of the complete regulatory complex with stoichiometry (alpha-beta-PLM)2.
Primary cutaneous apocrine carcinoma in a 50-year old male

Abstract Primary cutaneous apocrine carcinoma (PCAC) is a rare apocrine neoplasm that is challenging to diagnose due to its histologic and immunophenotypic overlap with other tumors, most notably metastatic breast carcinoma, and also bladder carcinoma. We present a case of a 50-year old male with an axillary mass diagnosed as primary apocrine carcinoma after surgical excision. Immunohistochemical evidence as well as clinical data were used to arrive at the final diagnosis of PCAC.
Sleep alterations following exposure to stress predict fear-associated memory impairments in a rodent model of PTSD

Sleep abnormalities, such as insomnia, nightmares, hyper-arousal, and difficulty initiating or maintaining sleep, are diagnostic criteria of posttraumatic stress disorder (PTSD). The vivid dream state, rapid eye movement (REM) sleep, has been implicated in processing emotional memories. We have hypothesized that REM sleep is maladaptive in those suffering from PTSD. However, the precise neurobiological mechanisms regulating sleep disturbances following trauma exposure are poorly understood. Using single prolonged stress (SPS), a well-validated rodent model of PTSD, we measured sleep alterations in response to stressor exposure and over a subsequent 7-day isolation period during which the PTSD-like phenotype develops. SPS resulted in acute increases in REM sleep and transition to REM sleep, and decreased waking in addition to alterations in sleep architecture. The severity of the PTSD-like phenotype was later assessed by measuring freezing levels on a fear-associated memory test. Interestingly, the change in REM sleep following SPS was significantly correlated with freezing behavior during extinction recall assessed more than a week later. Reductions in theta (4–10 Hz) and sigma (10–15 Hz) band power during transition to REM sleep also correlated with impaired fear-associated memory processing. These data reveal that changes in REM sleep, transition to REM sleep, waking, and theta and sigma power may serve as sleep biomarkers to identify individuals with increased susceptibility to PTSD following trauma exposure.
Mental Illness Detection at the World Well-Being Project for the CLPsych 2015 Shared Task

This article is a system description and report on the submission of the World Well-Being Project from the University of Pennsylvania in the ‘CLPsych 2015’ shared task. The goal of the shared task was to automatically determine Twitter users who self-reported having one of two mental illnesses: post traumatic stress disorder (PTSD) and depression. Our system employs user metadata and textual features derived from Twitter posts. To reduce the feature space and avoid data sparsity, we consider several word clustering approaches. We explore the use of linear classifiers based on different feature sets as well as a combination use a linear ensemble. This method is agnostic of illness specific features, such as lists of medicines, thus making it readily applicable in other scenarios. Our approach ranked second in all tasks on average precision and showed best results at .1 false positive rates.
Substantial Potentiality and Actuality

We have discussed Aristotle’s investigation of per se being in Meta. vii, in which the matter/form relation is not associated with the potentiality/actuality relation. Now it is time to turn to his study of potential/actual being in books viii and ix, that is, to examine the matter/form relationship in its association with the potentiality/actuality relationship.
Quality Control Techniques in Services Marketing

Service quality is becoming an increasing more important concern for marketing managers and executives. Many studies have been initiated to define service quality and to develop conceptual models for its implementation. In this paper we demonstrate the usefulness of Pareto analysis, Ishikawa cause and effect (Fishbone) diagrams, and process control charts as techniques for aiding management in the control of service quality. Difficulties which may be encountered when using traditionally product oriented quality control techniques in the service marketing environment are discussed.
Latin America's Cold War

Hal Brands (Cambridge, MA, Harvard University Press, 2010), 385 pp This provocative book, like other recent Cold War scholarship on Latin America, ascribes centrality to the actions, ideologies, an...
Alterations in Mitochondrial Morphology with Age-Associated Estrogen Deficiency and Ischemia-Reperfusion Injury

Acute myocardial infarction is the leading cause of death in post-menopausal women. While age-associated changes in mitochondrial morphology and dynamics are known to contribute to ischemia reperfu...
Oriented endocytic recycling of α5β1 in motile neutrophils

During cell migration, integrin attachments to the substratum provide the means to generate the traction and force necessary to achieve locomotion. Once the cell has moved over these attachments, however, it is equally important that integrins detach from the substratum. The fate of integrins after detachment may include release from the cell, lateral diffusion across the cell surface, or endocytosis and redelivery to the cell surface. Polymorphonuclear neutrophils (PMNs) become stuck on the extracellular matrix proteins fibronectin and vitronectin when their intracellular free calcium concentration ([Ca(++)]i) is buffered. Taking advantage of this feature of PMN migration, we investigated the fate of integrins to differentiate among various models of migration. We demonstrate that alpha5beta1, one of the fibronectin-binding integrins, is responsible for immobilization of [Ca(++)](i)-buffered PMNs on fibronectin. We find that alpha5 and beta1 are in endocytic vesicles in PMNs and that alpha5 colocalizes with a marker for an endocytic recycling compartment. When [Ca(++)](i) is buffered, alpha5 and beta1 become concentrated in clusters in the rear of the adherent cells, suggesting that [Ca(++)](i) transients are required for alpha5beta1 detachment from the substratum. Inhibition of alpha5beta1 detachment by buffering [Ca(++)](i) results in the depletion of alpha5 from both endocytic vesicles and the recycling compartment, providing compelling evidence that integrins are normally recycled by way of endocytosis and intracellular trafficking during cell migration. This model is further refined by our demonstration that the endocytic recycling compartment reorients to retain its localization just behind the leading lamella as PMNs migrate, indicating that membrane recycling during neutrophil migration has directionality. (Blood. 2000;95:2471-2480)
THE FINAL ANSWERS TO SINGLE UMBILICAL ARTERY

When the "Collaborative Study"1 was conceived it was undertaken with the hope of obtaining definitive answers to some complex questions in the field of obstetrics and perinatology. It could be anticipated that, by the meticulous collection of data on prenatal, natal, and postnatal events in thousands of pregnancies, indisputable evidence might be gained as to certain causes of mental retardation, birth defects, infectious complications of pregnancy, and the like. Ultimately, it was hoped that the application of such evidence might lead to measures for prevention. The study was enormous. An incredible amount of data still awaits analysis. The paper by Froehlich and Fujikura1 in this issue is but one small step toward the realization of the goals originally set.
ELECTROPHYSIOLOGIC STUDY AND RADIOFREQUENCY ABLATION IN PATIENTS WITH INTRACARDIAC TUMORS AND ACCESSORY PATHWAYS : IS THE TUMOR THE PATHWAY?

Ablation with Intracardiac Tumors. Introduction: There is a strong association of cardiac rhabdomyomas with the Wolff-Parkinson-White syndrome. This report describes the results of investigations in two patients with accessory pathway-mediated AV reciprocating tachycardia coexisting with intracardiac tumors. Methods and Results: Two patients with intracardiac tumors had mapping of the accessory pathway. Echocardiograms obtained in the electrophysiology laboratory while the ablation catheter was at the site of successful radiofrequency ablation demonstrated a close correspondence between the site of intracardiac tumor and the location of the accessory pathway. Conclusions: These results lend support to the hypothesis that accessory pathways in patients with intracardiac tumors, such as rhabdomyomas, are not typical Kent bundles, hut instead are either part of the intracardiac tumor or are closely related to the tumor. Ablation is possible in at least some patients with accessory pathways associated with intracardiac tumors.
Global Nomads: A Resource Hidden in Plain Sight

Maggie Appel–Schumacher shares her experiences as a “global nomad” and claims these often overlooked members of the student population should be integrated into the international focus of many coll...
Tetrafluoroethane (HFC 134A) propellant-driven aerosols of proteins.

Purpose. Develop metered-dose propellant-driven aerosols of proteins using tetrafluoroethane (HFC 134A) as propellant.
Alternate Overexpression of Two Phosphoglycoprotein Genes Is Associated with Changes in Multidrug Resistance in a J774.2 Cell Line

Abstract In multidrug-resistant murine J774.2 cells, the mdr1a and mdr1b genes encode the 120- and 125-kDa P-glycoprotein precursors, respectively (Hsu, S. I., Lothstein, L., and Horwitz, S.B. (1989) J. Biol. Chem. 264, 12053-12062). It is shown here that a J774.2 cell line selected for vinblastine resistance (J7.V3) switched from the 125- to 120-kDa precursor when cells that were maintained in 20 nM vinblastine were grown in 40 nM vinblastine for 20 months. The rate of switching was accelerated by growing cells in higher levels of vinblastine. These findings suggest that cells which express mdr1a have a selective growth advantage compared to cells which express mdr1b. Consistent with this hypothesis, the switching event that occurs in cells maintained at 40 nM vinblastine was correlated with 3.5-5-fold higher levels of resistance to vinblastine, taxol, and doxorubicin in the absence of any detectable increase in the amount of immunoreactive P-glycoprotein. These findings suggest that P-glycoproteins derived from mdr1a and mdr1b are functionally distinct.
Developing a Polymer Semiconductor Education Kit and Curriculum for High School Science Classrooms

Summary The development of a new science outreach program is described that uses a polymer semiconductor kit geared towards high school science classrooms. The kit is focused around educating students about polymeric semiconductors and contains materials and curriculum for three educational modules: a conductive polyaniline nanofiber module, a light-emitting diode module using poly(p-phenylene vinylene) (MEH-PPV), and a polymer solar cell using MEH-PPV and TiO2. A previous educational outreach program called “Juice from Juice” whose curriculum and activities explore the science and application of nanomaterials and molecules for low-cost solar cells inspired efforts to develop the polymer science outreach program. Key to the success of these programs is a methodology involving close collaboration between university research centers and high school science teachers both during development and implementation stages of the program.
A Review of “Peer to Peer and the Music Industry: The Criminalization of Sharing”

The world of music production and distribution has undergone drastic changes in the past decade, due mostly to the rise and refinement of peer-to-peer sharing. David's book explores the economic, s...
In Defense of Retaining Ipecac Syrup as an Over-the-Counter Drug

The occurrence of ipecac toxicity following chronic ipecac abuse is now well established in the medical literature, usually following self-administration by bulimic patients. In this issue of Pediatrics, Sutphen and Saulsbury1 identify chronic intentional ipecac administration by a parent to a child as another form of abuse leading to ipecac poisoning. In two prior reports (in abstract form) four additional pediatric victims who survived were identified.2,3 Additionally, a fatality following chronic ipecac administration to a 4-year-old child (again Munchausen syndrome by proxy) was reported to the American Association of Poison Control Centers 1987 National Data Collection System.4
Immune response of rats to group A streptococcal vaccine.

Abstract Adult female Sprague-Dawley rats were hyperimmunized with group A streptococcal vaccine in an attempt to evaluate this species for its immunological responsiveness to the group A streptococcal carbohydrate. Pronounced hyperproteinemia, generally attributable to hypergammaglobulinemia was produced in 30 to 40% of the animals. The immune response of the rats was extremely variable, yielding precipitating antibody concentrations ranging from 26 mg per ml. Antibody levels also varied considerably in the same rat at different times during the immunization routine. The highest concentration of precipitating antibody was 26.3 mg per ml. Evidence is presented to suggest the production of antibodies of restricted heterogeneity and the production of non-streptococcal antibodies during the immune response.
Collective Cell Movements Drive Morphogenesis and Elongation of the Avian Hindgut

At the end of gastrulation, the endoderm forms a single-cell thick epithelium lining the ventral surface of the developing embryo. Subsequently, through a series of poorly understood events, the initially flat endoderm is transformed into the gut tube, a cylindrical structure that gives rise to the epithelial lining of the entire respiratory and gastrointestinal tracts. In birds and mammals, formation of the gut tube begins with two invaginations at the anterior (head) and posterior (tail) poles of the embryo, termed the anterior (AIP) and caudal intestinal portals (CIP). It is thought that the AIP and CIP begin moving toward one another as two progressing waves of lateral-to medial folding (from left and right toward center), “zipping” the gut tube closed along the embryonic midline (Fig. 1A). This view of lateral-to-medial folding is, however, inconsistent with several observations. For example, fate mapping studies in chick and mouse that suggest that cells originating in the posterior end (toward the tail) of the flat endoderm do not form the hindgut, but instead contribute to the more anterior midgut [1, 2]. This would not be possible in a simple lateral-to-medial folding process. Therefore, it is largely unknown how this fundamental structure of the vertebrate body plan is established. The objective of the present work is to apply multi-photon live imaging of the chick embryo to determine how the hindgut is formed. Our findings suggest the hindgut arises from directed, collective cell movements that drive antero-posterior folding of the initially flat endoderm.Copyright © 2013 by ASME
MOCVD of GaN Using Diethylgalliumazide and Ammonia

GaN thin films have been deposited on Si and sapphire substrates by metalorganic chemical vapor deposition (MOCVD) using diethylgalliumazide and ammonia. Films were grown in the temperature range of 500-750°C. Growth rates were monitored in situ using laser interferometry. The addition of ammonia enhanced the growth rate significantly. At high temperatures, gas-phase depletion of the precursor reduced the growth rate of GaN. Films grown on (0001)-oriented sapphire substrates at temperatures above 650°C were highly textured with smooth surface morphology. Optical and electrical properties of the films are discussed and compared to those of films grown using conventional Ga and N sources.
Playing cat and mouse at the U.S.-Mexican border.

Border control and apprehension activity represents a major element of the Immigration Reform and Control Act of 1986. Does apprehending an undocumented migrant deter remigration? If it does not, does it change future migration behavior? I explore these questions by testing hypotheses about the effects of apprehension on the actual and desired length of stay in the United States and on the frequency of migration for undocumented Mexican male migrants. Results suggest that INS policy may well be backfiring. Migrants stay in the United States longer on non-apprehended trips and stay in Mexico for shorter spells between trips to compensate for the cost of a past apprehension.
Spectra Of Fields Diffracted By Moving Apertures In Front Of An Incoherent Source

A derivation of the temporal spectrum a the far zone field diffracted by a uniformly translating planar aperture in front of a quasimonochromatic, temporally stationary, spatially homogeneous, incoherent, primary source is performed and numerical examples are provided. It is shown that the diffracted field spectrum can be expressed as the convolution of the spectrum of the source with a "modulating spectrum" determined by the shape and velocity of the aperture, as well as the direction of observation in the far zone.
KAIRO 3: A modular reconfigurable robot for search and rescue field missions

Search and rescue field missions, especially in environments which are dangerous for humans, increasingly requires the usage of robust and flexible robots. We describe the development of the modular reconfigurable robot KAIRO 3 focusing on applications in search and rescue, inspection and maintenance. After a short retrospect of previous generations of modular robots, the latest design of KAIRO 3 is presented. In particular, enhancements of the mechatronics and the control software are shown. Furthermore, the necessity to increase the flexibility of search and rescue robots will be demonstrated. To comply with this requirement, we utilized reconfiguration and adaptation of modular robots. Finally, the field results of applying KAIRO 3 at a civil protection field exercise are discussed.
Secret Communication via Multi-antenna Transmission

For a multiple antenna Gaussian broadcast channel, we look for inputs that facilitate secret transmission between authorized communication parties in the presence of passive eavesdroppers. In this work, we assume all channel information is known at the transmitter. For the general multiple antenna system, we find that the problem of optimizing over Gaussian inputs for achievable secrecy rate is not convex, making it difficult to solve. However, for the simpler case where multiple transmit antennas are deployed with only a single receive antenna used at both the intended receiver and the eavesdropper, the problem can be solved easily. The analytical solution for this case is presented.
Time Step Size Selection for Radiation Diffusion Calculations

The purpose of this note is to describe a time step control technique as applied to radiation diffusion. Standard practice only provides a heuristic criteria related to the relative change in the dependent variables. The authors propose an alternative based on relatively simple physical principles. This time step control applies to methods of solution that are unconditionally stable and converges nonlinearities within a time step in the governing equations. Commonly, nonlinearities in the governing equations are evaluated using existing (old time) data. The authors refer to this as the semi-implicit (SI) method. When a method converges nonlinearities within a time step, the entire governing equation including all nonlinearities is self-consistently evaluated using advance time data (with appropriate time centering for accuracy).
Sequence Specific Role of Water in Spontaneous Local Unwinding of Collagen

Collagen is one of the most abundant proteins in the human body. Due to its biological significance and omnipresence, it has been intensely studied for several decades both at the molecular and at the tissue level. A single collagen molecule is a rope like super helix of three α-chains. Collagen molecules self assemble in an orderly fashion to form different suprastructures such as fibrils and networks, providing mechanical strength to the tissue. Collagen density and suprastructural organization determines the local mechanical tension in a particular region of the tissue. Cells sense the tension and in turn trigger a controlled process of growth and remodeling of tissues through secretion or degradation of extracellular components including collagen. Tissue homeostasis is a complex process and adding to such complexity, a single collagen molecule is unstable at body temperature [1], but its stability increases after self-assembly and cross-linking.Copyright © 2007 by ASME
Restricted shallow-water sedimentation of Early Archean stromatolitic and evaporitic strata of the Strelley Pool Chert, Pilbara Block, Western Australia

Abstract The 3.4 Ga-old Strelley Pool Chert is a 25-m thick sedimentary unit near the top of the predominantly volcanic Warrawoona Group in greenstone belts of the eastern Pilbara Block, Western Australia. It is here subdivided into 5 members containing 13 lithofacies. The basal Member, I, is composed of quartzose sandstone deposited in a high-energy wave- or tide-dominated shallow-water system. Overlying this are Members II and III, which make up the bulk of the formation and were deposited in a low-energy, partially restricted hypersaline basin. They record a predominantly regressive succesion of deposits including subaqueous laminite, stromatolite and evaporite; stromatolite, carbonaceous laminite, black-and-white banded chert, evaporite and intraformational detrital units deposited under intermittently to predominantly exposed conditions; and subaerially deposited windblown sand, evaporite and evaporite-solution layers. Members IV and V record the progradation of a volcaniclastic alluvial fringe. The Strelley Pool Chert represents an association of sedimentary environments directly comparable to that observed in modern, low-energy, shallow-marine carbonate-evaporite systems, such as along the Trucial Coast of the Persian Gulf, and abundantly developed in Phanerozoic carbonate platform deposits. There is no evidence, however, that uniquely identifies the environment as having been marine. Deposition may have taken place in either a large hypersaline lake or a restricted marine basin. Evidence of predominantly low energy depositional conditions and a paucity of terrigenous detritus indicate that sedimentation was dominated by orthochemical and biological processes. Silicified evaporites, including coarsely crystalline layers resembling Messinian selenite, are widespread and similar to younger evaporite deposits. They clearly indicate that evaporites were common within shallow-water Archean sequences. The presence of an assemblage of biogenic deposits, including organic laminite, stromatolites, encrusting carbonaceous mats, carbonaceous granules and oncolites, deposited under conditions ranging from fully subaqueous to nearly subaerial and locally evaporitic, points to the existence of an ecologically and probably biologically diverse microbial community 3.4 Ga ago.
Quasi-medians are robust and relatively efficient estimators of a common mean given multivariate normality

In this note we examine the efficiency of averaging marginal quasi-medians as compared to averaging marginal sample means when estimating a common location parameter given multivariate normal data. It is shown that the efficiency of certain quasi-medians approach that of the sample mean as the dimension of the problem grows larger. Modest gains in efficiency may be had even when the dimension of the problem is extended from the univariate setting to the bivariate setting.
'You'd Be Wanting to Know about the Past': social contexts of children's historical understanding in Northern Ireland and the USA

This research reports the results of two studies of young children's historical thinking, one conducted in Northern Ireland and one in the USA. In both countries, primary/elementary students learn about history in a variety of settings, including not only schools but also family conversations, historic sites and the media. The differing nature of historical representations in the two countries, however, leads students to contrasting conclusions about the purpose of learning about the past: in the USA, students emphasise that history is important so that they will know about the origin of their country and their own place within it, while in Northern Ireland students describe the purpose of history as being to learn about those who are different from themselves. In both countries, such comparative evidence about children's thinking provides educators with the opportunity to consider how they can build on and extend students' understanding of history.
Tests of 4 controlling-element systems of maize for mutator activity and their interaction with Mu mutator

Abstract The maize mutator system, Mu, behaves in a non-Mendelian manner that may be expected if it were an extremely active controlling-element system. To test this hypothesis, the maize controlling-element systems, adtDt, DsAc ( MP), IEn, and rcuFcu were tested for mutation activity. DsAc and rcuFcu tests were the only ones in which new mutants were induced, but at a frequency much lower than that found in Mu crosses. The mutation frequency in these controlling-element systems does not differ statistically from that found in control (Non-Mu) populations. Tests also were made to determine if Mu will substitute for the regulatory element of any of the 4 conotrolling-element. All tests were negative, suggesting that, if Mu is a controlling-element system, it is a different one from those previously described.
Psychology Computers and Classroom Social Processes—A Review of the Literature

The impact of computer use on classroom structure and functioning is examined. The most consistently found effect is an increase in motivation and closely related constructs. Computer use also appe...
Measuring what matters: Effectively predicting language and literacy in children with cochlear implants

Abstract Objectives To evaluate how well various language measures typically used with very young children after they receive cochlear implants predict language and literacy skills as they enter school. Methods Subjects were 50 children who had just completed kindergarten and were 6 or 7 years of age. All had previously participated in a longitudinal study from 12 to 48 months of age. 27 children had severe-to-profound hearing loss and wore cochlear implants, 8 had moderate hearing loss and wore hearing aids, and 15 had normal hearing. A latent variable of language/literacy skill was constructed from scores on six kinds of measures: (1) language comprehension; (2) expressive vocabulary; (3) phonological awareness; (4) literacy; (5) narrative skill; and (6) processing speed. Five kinds of language measures obtained at six-month intervals from 12 to 48 months of age were used as predictor variables in correlational analyses: (1) language comprehension; (2) expressive vocabulary; (3) syntactic structure of productive speech; (4) form and (5) function of language used in language samples. Results Outcomes quantified how much variance in kindergarten language/literacy performance was explained by each predictor variable, at each earlier age of testing. Comprehension measures consistently predicted roughly 25–50 percent of the variance in kindergarten language/literacy performance, and were the only effective predictors before 24 months of age. Vocabulary and syntactic complexity were strong predictors after roughly 36 months of age. Amount of speech produced in language samples and number of answers to parental queries explained moderate amounts of variance in performance after 24 months of age. Number of manual gestures and nonspeech vocalizations produced in language samples explained little to no variance before 24 months of age, and after that were negatively correlated with kindergarten performance. The number of imitations produced in language samples at 24 months of age explained about 10 percent of variance in kindergarten performance, but was otherwise not correlated or negatively correlated with kindergarten outcomes. Conclusions Before 24 months of age, the best predictor of later language success is language comprehension. In general, measures that index a child's cognitive processing of language are the most sensitive predictors of school-age language abilities.
Development of size structure in tiger salamanders: the role of intraspecific interference

Cannibalism affects patterns of density-dependent mortality and may regulate population size. In many cases, rates of cannibalism depend on size structure, the frequency distribution of body sizes in the population, because cannibals can often only capture and consume smaller individuals. Size differences within single-age groups can be caused by a variety of factors. In this research we tested the hypothesis that size variation among larval tiger salamanders is due, in part, to interference interactions among individuals of different sizes. We found that size variation was greater when we raised larvae in groups rather than in isolation. This increase in size variation was due more to a relative deceleration of growth among smaller individuals rather than acceleration among larger individuals. We also found that smaller larvae had lower feeding rates than larger larvae when in groups, but not when isolated. Including spatial structure to limit physical interactions did not affect the size specificity of feeding rate, although it reduced feeding rates overall. We argue that these results are consistent with the hypothesis that larger larvae interfere, probably indirectly, with the feeding behavior of small individuals and this contributes to increases in size variation over time. We hypothesize that this indirect interference is caused by a behavioral response of smaller larvae to the risk of predation (cannibalism) by larger individuals.
Effects of dopamine depletions in the medial prefrontal cortex on DRL performance and motor activity in the rat

Two experiments assessed the behavioral effects of dopamine depletions in the medial prefrontal cortex that were produced by injection of the neurotoxic agent 6-hydroxydopamine. In the first experiment, rats were trained to respond on a differential reinforcement of low rates of responding-30 second (DRL30) schedule. On this schedule, rats were only reinforced if they withheld responding for 30 s. Rats with prefrontal dopamine depletions were found to be impaired in the DRL task. These animals responded more than controls, received fewer reinforcers, and were less efficient in their responses. Moreover, an analysis of interresponse times (IRTs) revealed that rats with medial prefrontal dopamine depletions made more responses with short-duration IRTs, and fewer responses with long-duration IRTs. In the second experiment, rats were tested on open field activity, amphetamine-induced locomotor activity and stereotypy. No increase in spontaneous locomotor activity was found following surgery; however, increases in amphetamine-induced locomotor activity and stereotypy were observed. These results are consistent with hypothesized role for the prefrontal cortex in behavioral inhibition, and indicates that prefrontal cortical dopamine is an integral part of the system.