cssi/SciSciGPT-SciSciNet huggingface dataset:
Vibration properties of and power harvested by a system of electromagnetic vibration energy harvesters that have electrical dynamics

Abstract This study investigates the vibration and dynamic response of a system of coupled electromagnetic vibration energy harvesting devices that each consist of a proof mass, elastic structure, electromagnetic generator, and energy harvesting circuit with inductance, resistance, and capacitance. The governing equations for the coupled electromechanical system are derived using Newtonian mechanics and Kirchhoff circuit laws for an arbitrary number of these subsystems. The equations are cast in matrix operator form to expose the device’s vibration properties. The device’s complex-valued eigenvalues and eigenvectors are related to physical characteristics of its vibration. Because the electrical circuit has dynamics, these devices have more natural frequencies than typical electromagnetic vibration energy harvesters that have purely resistive circuits. Closed-form expressions for the steady state dynamic response and average power harvested are derived for devices with a single subsystem. Example numerical results for single and double subsystem devices show that the natural frequencies and vibration modes obtained from the eigenvalue problem agree with the resonance locations and response amplitudes obtained independently from forced response calculations. This agreement demonstrates the usefulness of solving eigenvalue problems for these devices. The average power harvested by the device differs substantially at each resonance. Devices with multiple subsystems have multiple modes where large amounts of power are harvested.
A novel methodology for assessing laryngeal and vagus nerve integrity in patients under general anesthesia.

Abstract Objective To describe a novel methodology for intraoperative neuro-monitoring of laryngeal and vagus nerves by utilizing the laryngeal adductor reflex (LAR). Methods Case series of 15 patients undergoing thyroid and cervical spine surgeries under total intravenous general anesthesia. Vocal fold mucosa was electrically stimulated to elicit a LAR using endotracheal tube based electrodes. Contralateral R1 (cR1) and R2 (cR2) responses were recorded using the endotracheal tube electrode contralateral to the simulating electrode. Results The LAR was reliably elicited in 100% of patients for the duration of each surgical procedure. Mean onset latency of cR1 response was 22.4 ± 2.5 ms (right) and 22.2 ± 2.4 ms (left). cR2 responses were noted in 10 patients (66.7%). No peri-operative complications or adverse outcomes were observed. Conclusions The LAR is a novel neuro-monitoring technique for the vagus nerve. Advantages over current monitoring techniques including simplicity, ability to continuously monitor neural function without placement of additional neural probes and ability to assess integrity of both sensory and motor pathways. Significance The LAR represents a novel method for intraoperatively monitoring laryngeal and vagus nerves. The LAR monitors the entire vagus nerve reflex arc and is thus applicable to all surgeries where vagal nerve integrity may be compromised.
A Conversation with Emery Neal Castle

This article presents the transcript of an interview with the eminent economist, Emery Neal Castle. Emery discusses his youth in rural Kansas and how it shaped him and his career. After several years in the US Army Air Force during World War II, Emery returned to Kansas State University for his undergraduate studies and then completed his PhD at Iowa State University. He eventually landed at Oregon State University (OSU) in the mid-1950s, where he taught farm management and developed early courses in water resource economics. Emery and colleagues nurtured what became a world-renowned resource economics program at OSU. Emery also spent a decade running the nonprofit public policy research organization Resources for the Future in Washington, DC. Throughout his long career, Emery made significant contributions to three subfields of applied economics: farm management, resource economics, and rural studies. Emery has received numerous awards for his impact on the profession and the agricultural economy.
Treatment of preaxial polydactyly.

Abstract Preaxial polydactyly is the result of aberrant bifurcation of the embryonic preaxial anlage. Effective reconstruction of thumb duplication requires careful evaluation of all components. Skin, nail, bone, ligament, and musculoskeletal elements must be combined to reconstruct an optimal digit.
Microfluidic Alpha Spectrometry of UOX PWR UNF in a Molten Salt

This paper presents the computational performance of microfluidic channels (MFCs) within a semiconductor detector to monitor changes in the elemental and isotopic composition of a UOX pressurized w...
Ecological Thinking in Science and Public

This chapter traces a broad history of ecological thinking, starting with the early proto-ecological natural scientists in the eighteenth and nineteenth centuries. After laying out some of these early conceptions of ecology, we then turn to the social sciences and humanities, exploring how ecological thinking influenced sociology, anthropology, psychology, ethnography, and philosophy. From this foundation, we suggest that ecological thinking can be used to revisit the concept of ecological validity, originally developed in the mid-twentieth century by psychologists Egon Brunswik and Kurt Lewin. This chapter concludes by explaining how ecological validity and ecological thinking in general provide public engagement with science both concrete guidelines for better research and heuristics for evaluating the strengths and weaknesses of competing engagement methods.
RSSI-based spoofing detection in smart grid IEEE 802.11 home area networks

The smart grid concept has compelled researchers to investigate cybersecurity approaches for infrastructure stability. Wireless mediums represent the backbone of communications in the smart grid especially for Home Area Networks (HAN). Increased connectivity brings about an inheritance of vulnerabilities associated with wireless networks. In particular, spoofing attacks poses an immediate threat to Confidentiality, Integrity, and Availability (CIA). In this study, an intrusion detection system (IDS) algorithm is proposed in which received signal strength indicator (RSSI) is analyzed by means of cosine similarity and data sectoring to detect spoofing attacks in smart grid 802.11 HANs. The detection accuracies are recorded at different spoofing distances and threshold levels.
Sex and age differences in head acceleration during purposeful soccer heading.

ABSTRACTDifferences in head–neck segment mass, purposeful heading technique, and cervical strength and stiffness may contribute to differences in head accelerations across sex and age. The purpose of this study was to compare head acceleration across sex and age (youth [12–14 years old], high school and collegiate) during purposeful soccer heading. One-hundred soccer players (42 male, 58 female, 17.1 ± 3.5 years, 168.5 ± 20.3 cm, 61.5 ± 13.7 kg) completed 12 controlled soccer headers at an initial ball velocity of 11.2 m/s. Linear and rotational accelerations were measured using a triaxial accelerometer and gyroscope and were transformed to the head centre-of-mass. A MANOVA revealed a significant multivariate main effect for sex (Pillai’s Trace = .165, F(2,91) = 11.868, p < .001), but not for age (Pillai’s Trace = .033, F(4,182) = 0.646, p = .630). Peak linear and rotational accelerations were higher in females (40.9 ± 13.3 g; 3279 ± 1065 rad/s2) than males (27.6 ± 8.5 g, 2219 ± 823 rad/s2). These data su...
OSCILLATORY NATURAL CONVECTION IN A LONG HORIZONTAL CAVITY

Natural convection of a low Prandtl number fluid in a differentially heated shallow horizontal cavity has been studied numerically by means of a finite volume technique. The two dimensional flow undergoes a Hopf bifurcation as the Grashof number increases, and the oscillations are associated with growing and shrinking of corotating vortex cells in the enclosure. When a three dimensional procedure is employed, the flow in the cavity consists of one cell only, and the transition to periodic flow occurs much later than by two dimensional predictions.
Irrigation Volume, Application, and Controlled-release Fertilizers: I. Effect on Plant Growth and Mineral Nutrient Content in Containerized Plant Production

Abstract An experiment with four volumes of irrigation and five controlled-release fertilizers (CRFs) was conducted to evaluate effects on plant growth and mineral nutrient content. Rooted cuttings...
Gender is what you look like: Emerging gender identities in young children and preoccupation with appearance

Our work examining young children’s strong desire to wear gender-stereotypical clothing suggests that physical appearance may be early reflections of developing gender identities. We test implicati...
It Takes a Village: Documenting the Contributions of Non-Scientific Staff to Scientific Research

Science, especially large-scale basic research, is a collaborative endeavor, often drawing on the skills of people from a wide variety of disciplines. These people include not just scientists, but also administrators, engineers, and many others. Fermilab, a Department of Energy National Laboratory and the United States' premier particle physics laboratory, exemplifies this kind of research; many of its high-energy physics experiments involve hundreds of collaborators from all over the world. The Fermilab Archives seeks to document the history of the lab and the unique scientific research its staff and visitors perform. Adequately documenting the lab's work often requires us to go far beyond things like the writings and correspondence of scientists to also capture the administrative and social histories of the experiments and the context in which they were performed. At Fermilab, we have sought to capture these elements of the lab's activities through an oral history program that focuses on support staff as well as physicists and collection development choices that recognize the importance of records documenting the cultural life of the lab. These materials are not merely supplementary, but rather essential documentation of the many types of labor that go into the planning and execution of an experiment or the construction of an accelerator and the context in which this work is performed.
What Is The Student Referring To? Mapping Properties and Concepts in Students' Systems of Physics Equations

An ITS dealing with students' algebraic solutions to Physics problems needs to map the student variables and equations onto the physical properties and constraints involved in a known correct solution. Only then can it determine the correctness and relevance of the student's answer. In earlier papers we described methods of determining the dimensions (the physical units) of student variables. This paper describes the second phase of this mapping, determining which specific physical quantity each variable refers to, and which part of the set of constraints imposed by physics principles each student equation incorporates. We show that knowledge of the dimensions of the variables can be used to greatly reduce the number of possible mappings.
The influence of large eddies on the structure of turbulent premixed flames characterized with stereo-PIV and multi-species PLIF at 20 kHz

Abstract Interactions between turbulent structures (eddies) and premixed flame fronts were characterized with simultaneous CH2O-/OH-PLIF and stereo-PIV at high framing rate (20 kHz). The high temporal resolution of these measurements permitted the tracking and subsequent characterization of the evolution of turbulence–flame interactions. Common events were identified and their effects on the flame structure were assessed, the first of these being that the flame front was locally broadened by large eddies (i.e. those larger than twice the laminar flame thickness). The results suggest that large eddies likely have a two-fold effect on the overall propagation rate, one linked to the increase in burning area (consistent with classical theories) and the other stemming from an enhancement in the local diffusivity experienced by the flame. While this latter point has not been predicted, it has been postulated that large eddies could convect preheated fluid upstream of the flame. To our knowledge the results presented here provide the first conclusive experimental evidence of this phenomenon. The second common event was the persistence of locally thin preheat layers through extremely turbulent flow fields (i.e. those possessing scales much smaller than the laminar flame thickness). Comparisons between sequences of such events and those where broadening occurred indicate that the latter is typically associated with elevated turbulent diffusivity, which supports arguments in favor of using a criterion based on a ratio of diffusivities rather than length scales to predict the onset of preheat-zone broadening.
Novel magnetic core-shell nanoparticles for the removal of polychlorinated biphenyls from contaminated water sources.

Abstract In this work, we developed novel core-shell nanoparticle systems with magnetic core and polymer shell via atom transfer radical polymerization for use as high affinity nanoadsorbents for organic contaminants in water and wastewater treatment. Polyphenolic-based moieties, curcumin multiacrylate (CMA) and quercetin multiacrylate (QMA), were incorporated into poly(ethylene glycol) (PEG) based polymeric shells to create high affinity binding sites for the capture of polychlorinated biphenyls (PCBs) as a model pollutant. The resulting magnetic nanoparticles (MNPs) were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), X-ray diffraction (XRD), dynamic light scattering (DLS), and UV-visible spectroscopy. The affinity of these novel materials for PCB 126 was evaluated and fitted to the nonlinear Langmuir model to determine binding affinities (KD). The KD values obtained were: PEG MNPs (8.42 nM)
Critical properties of 4 He in aerogel near the λ-line

We measured the superfluid fraction ρs/ρ and the isobaric thermal expansion coefficient βP of4He confined in an aerogel. Data were obtained near the λ-line along several isobars. Powerlaw fits to the results for ρs/ρ as a function of t≡T/Tc−1 (Tc is the transition temperature) give a pressure—independent exponent ς=0.755 when a confluent singular term is included. Fits to the βP data of power laws yield the specific-heat exponents α≅−0.6 and α′≅−1.0≠α above and below Tc respectively. When an analytic background term a×t is included in the fit, the pressure-independent value α=α′≅−0.59 is permitted, but the amplitude ratio A′/A is found to be near zero and the coefficient of the analytic term is large. The measured values for ς and α′ or α are inconsistent with hyperscaling in three dimensions.
Symbiotic Root-Endophytic Soil Microbes Improve Crop Productivity and Provide Environmental Benefits.

Plants should not be regarded as entities unto themselves, but as the visible part of plant-microbe complexes which are best understood as “holobiomes.” Some microorganisms when given the opportunity to inhabit plant roots become root symbionts. Such root colonization by symbiotic microbes can raise crop yields by promoting the growth of both shoots and roots, by enhancing uptake, fixation, and/or more efficient use of nutrients, by improving plants’ resistance to pests, diseases, and abiotic stresses that include drought, salt, and other environmental conditions, and by enhancing plants’ capacity for photosynthesis. We refer plant-microbe associations with these capabilities that have been purposefully established as enhanced plant holobiomes (EPHs). Here, we consider four groups of phylogenetically distinct and distant symbiotic endophytes: (1) Rhizobiaceae bacteria; (2) plant-obligate arbuscular mycorrhizal fungi (AMF); (3) selected endophytic strains of fungi in the genus Trichoderma; and (4) fungi in the Sebicales order, specifically Piriformospora indica. Although these exhibit quite different “lifestyles” when inhabiting plants, all induce beneficial systemic changes in plants’ gene expression that are surprisingly similar. For example, all induce gene expression that produces proteins which detoxify reactive oxygen species (ROS). ROS are increased by environmental stresses on plants or by overexcitation of photosynthetic pigments. Gene overexpression results in a cellular environment where ROS levels are controlled and made more compatible with plants’ metabolic processes. EPHs also frequently exhibit increased rates of photosynthesis that contribute to greater plant growth and other capabilities. Soil organic matter (SOM) is augmented when plant root growth is increased and roots remain in the soil. The combination of enhanced photosynthesis, increasing sequestration of CO2 from the air, and elevation of SOM removes C from the atmosphere and stores it in the soil. Reductions in global greenhouse gas levels can be accelerated by incentives for carbon farming and carbon cap-and-trade programs that reward such climate-friendly agriculture. The development and spread of EPHs as part of such initiatives has potential both to enhance farm productivity and incomes and to decelerate global warming.
The impact of combining pain education strategies with physical therapy interventions for patients with chronic pain: A systematic review and meta-analysis of randomized controlled trials.

ABSTRACTStudy Design: Systematic Review with meta-analysis.Background: Rehabilitation providers have begun to incorporate pain education into their treatment protocols to influence the patient’s ex...
Towards highly available clos-based WAN routers

The performance and availability of cloud and content providers often depends on the wide area networks (WANs) they use to interconnect their datacenters. WAN routers, which connect to each other using trunks (bundles of links), are sometimes built using an internal Clos topology connecting merchant-silicon switches. As such, these routers are susceptible to internal link and switch failures, resulting in reduced capacity and low availability. Based on the observation that today's WAN routers use relatively simple trunk wiring and routing techniques, we explore the design of novel wiring and more sophisticated routing techniques to increase failure resilience. Specifically, we describe techniques to 1) optimize trunk wiring to increase effective internal router capacity so as to be resilient to internal failures, 2) compute the effective capacity under different failure patterns, and 3) use these to compute compact routing tables under different failure patterns, since switches have limited routing table sizes. Our evaluations show that our approach can mask failures of up to 75% of switches in some cases without exceeding routing table limits, whereas competing techniques can sometimes lose half of a WAN router's capacity with a single failure.
The co-development of chores and effortful control among Mexican-origin youth and prospective work outcomes

Abstract The present research examined: (a) the co-development of chores and effortful control, and (b) the prospective impact of effortful control development (i.e., initial levels and the trajectory of effortful control from late childhood through adolescence) on work outcomes in young adulthood. We used data from a longitudinal study of 674 Mexican-origin youth assessed at ages 10, 12, 14, 16, and 19. We found no evidence of co-developmental associations between chores and effortful control, but we found that higher initial levels of effortful control (age 10) predicted working-student status, less job stress, and better job fit, and steeper increases in effortful control from age 10 to 16 predicted higher job satisfaction and job autonomy in young adulthood (age 19).
Towards Industrial IoT-AR Systems using Deep Learning-Based Object Pose Estimation

Augmented Reality (AR) is known to enhance user experience, however, it remains under-adopted in industry. We present an AR interaction system improving human-machine coordination in Internet of Things (IoT) and Industry 4.0 applications including manufacturing and assembly, maintenance and safety, and other highly-interactive functions. A driver of slow adoption is the computational complexity and inaccuracy in localization and rendering digital content. AR systems may render digital content close to the associated physical objects, but traditional object recognition and localization modules perform poorly when tracking texture-less objects and complex shapes, presenting a need for robust and efficient digital content rendering techniques. We propose a method of improving IoT-AR by integrating Deep Learning with AR to increase accuracy and robustness of the target object localization module, taking both color and depth images as input and outputting the target’s pose parameters. Quantitative and qualitative experiments prove this system’s efficacy and show potential for fusing these emerging technologies in real-world applications.
Universal Gray Finite Elements for Heat Transfer Analysis in the Presence of Uncertainties

A new finite element method is presented for the analysis of uncertain heat transfer problems using universal gray number theory. The universal gray number representation involves normalization of ...
Effect of malnutrition-driven nutritional support protocol on clinical outcomes in autologous stem cell transplantation patients

Poor nutrition status in patients receiving high-dose chemotherapy and autologous stem cell transplant (ASCT) has been associated with inferior clinical outcomes. We aim to determine whether a malnutrition-driven nutritional support protocol can improve these outcomes. In this prospective cohort study, we assessed adults for malnutrition who were consecutively admitted for ASCT between October 2017 and March 2019 (n = 251), and provided enteral or parenteral nutrition (EN/PN) to patients who were malnourished early in the transplantation admission. We compared their clinical outcomes with those of a historical cohort admitted between May 2016 and October 2017 (n = 257) for whom nutrition assessment and initiation of EN/PN were not protocol-driven. Patients receiving ASCT during the intervention period experienced decreased odds of prolonged hospital stay (p = 0.023), central line–associated bloodstream infection (p = 0.015), mucosal barrier injury (p = 0.037), and high weight loss (p = 0.002), in a multivariate analysis as compared with those receiving ASCT during the control period. Outcomes for ICU transfer, deconditioning on discharge, time to platelet engraftment, and unplanned 30-day hospital readmission did not differ significantly between groups. A malnutrition-driven nutritional support protocol may improve outcomes for ASCT patients.
PASTA: A State-Space Representation for In-Line Estimation of Time-Varying Parameters of Market Response Models

This article presents a state-space representation known as parameters as states (PASTA) for linear market response models with time-varying parameters. The PASTA representation enables (a) conversion of the problem of estimating the time-varying effectiveness of marketing interventions from a maximum likelihood–based, offline estimation to a Bayesian, update-based, in-line estimation; (b) development of a computationally efficient approach to estimating and tracking time-varying parameters; and (c) early estimates of the effectiveness of marketing interventions and changes in that effectiveness. These characteristics are important in today’s digital marketing world, in which data availability, the size of the marketer’s decision space, the computational complexity of the estimation problem, market dynamics, and significance of proactive marketing are factors of increased in importance. We also present a Kalman filter–based estimation approach that can be used in conjunction with PASTA and establish the stability, observability, and optimality of the estimator. Using computational studies to supplement theoretical results and compare parameter estimates obtained from PASTA with those using ordinary least squares and recursive least squares, we show that PASTA-based estimation reduces the impact of collinearity, autocorrelation, and measurement errors on the quality of the estimates.
In-Plane Vibration of a Deployable Segmented Ring

The in-plane vibrations of regular polygonal rings composed of rigid segments joined by torsional springs are studied for the first time. The nonlinear dynamical difference equations are formulated...
Anticoagulant Usage Following Anterior Cruciate Ligament Reconstruction is Associated with Increased Rate of Manipulation Under Anesthesia

Objectives:Although uncommon, arthrofibrosis following anterior cruciate ligament reconstruction (ACLR) is considered to be a significant and disabling complication for a young, athletic population...
XM808 Sub Caliber Trainer Life Distribution Analysis

This reliability data analysis case study demonstrates the use of a variety of statistical techniques, such as life data analysis for censored data, Monte Carlo simulation, and optimization, to develop credible predictions for a system in use by the US Army. As the US Army moves toward the goal of ‘leveraging data as a strategic asset’, this type of formal analysis provides the opportunity to showcase the use of statistical methods and best practices which are scalable for the purpose of fleet-wide system reliability assessments, analysis of field data, and enterprise-level machine learning-enabled tasks.
Functional Morphology of Gliding Flight I. Modeling Reveals Distinct Performance Landscapes Based on Soaring Strategies

The physics of flight influences the morphology of bird wings through natural selection on flight performance. The connection between wing morphology and performance is unclear due to the complex relationships between various parameters of flight. In order to better understand this connection, we present a holistic analysis of gliding flight that preserves complex relationships between parameters. We use a computational model of gliding flight, along with analysis by uncertainty quantification, to (1) create performance landscapes of gliding based on output metrics (maximum lift-to-drag ratio, minimum gliding angle, minimum sinking speed, and lift coefficient at minimum sinking speed) and (2) predict what parameters of flight (chordwise camber, wing aspect ratio [AR], and Reynolds number) would differ between gliding and nongliding species of birds. We also examine performance based on the soaring strategy for possible differences in morphology within gliding birds. Gliding birds likely have greater ARs than non-gliding birds, due to the high sensitivity of AR on most metrics of gliding performance. Furthermore, gliding birds can use two distinct soaring strategies based on performance landscapes. First, maximizing distance traveled (maximizing lift-to-drag ratio and minimizing gliding angle) should result in wings with high ARs and middling-to-low wing chordwise camber. Second, maximizing lift extracted from updrafts should result in wings with middling ARs and high wing chordwise camber. Following studies can test these hypotheses using morphological measurements.
Experimental Demonstration of Charge- Balanced GaN Super-Heterojunction Schottky Barrier Diode Capable of 2.8 kV Switching

This letter reports an experimental demonstration of charge-balanced GaN super-heterojunction Schottky barrier diodes (SHJ-SBDs). Charge balance between the n-type delta-doping and the p-type doping was achieved by adjusting the thickness of the pGaN. This device structure enabled scaling of breakdown voltage to over 3 kV, and dynamic switching up to 2.8 kV without using any field-plate.
Probability, Uncertainty, and Liquidity in the General theory (1936) and the General theory of Employment (1937) Always Comes in Degrees: Ergodicity-Nonergodicity Does not Come in Degrees

Post Keynesians, starting with the work of Joan Robinson, G. L. S. Shackle, Sydney Weintraub, and Paul Davidson, have portrayed Keynes’s General Theory and Post General Theory work on the concepts of uncertainty and probability in strictly binary terms, like knowledge-unknowledge, certainty-uncertainty, open–closed, or ergodic-nonergodic. There is no room for Keynes’s fundamental concept of degrees in these Post Keynesian binary representations, which directly conflict with Keynes’s constant categorization throughout his lifetime that probability, liquidity, liquidity preference, disquitetude and uncertainty came in degrees, simply means that Post Keynesians are not Keynesians. There are no binary concepts that appear in Keynes’s decision theory anywhere in anything that he published in his lifetime, be it the A Treatise on Probability, A Treatise on Money, General Theory, or The General Theory of Employment.
Home and Neighborhood Context of Falls Among Black and White Older Americans.

Objectives: To examine social and physical environmental fall-risk factors in a nationally representative sample of community-living older adults overall and by racial group. Methods: We used data ...
Suicidal Ideation Among International Students: The Role of Cultural, Academic, and Interpersonal Factors:

We examined two structural equation models of international students’ suicidal ideation using data from 595 international students in two public universities in the United States. The models repres...
OPORTUNIDADES DE INVESTIGACIÓN EN HELMINTOLOGÍA EN PERÚ: MI PROPIA EXPERIENCIA

As a professor of Parasitology and Invertebrate Biology at a small, private liberal arts college in the United States, where I study the transmission ecology of trematode parasites, to date my research experience studying helminths in the Neotropical region has been limited. Of course, many parasitologists in North America and elsewhere have relatively limited exposure to neotropical helminthology beyond textbooks and the primary literature; however, based on my own experience over the last year I believe there exists great opportunity for this to change. The potential for wonderful and productive collaborations continues to increase with greater ease of travel and levels of cooperation and information-sharing. So, while by definition my own experience in Peru is unique to me, I hope that it highlights some of the opportunities for research in helminthology in Peru and thus encourages additional collaborations in the future.
Anatomic location and mechanism of hiatal hernia recurrence: a video-based assessment.

INTRODUCTION Hiatal hernia recurrence following surgical repair is common. We sought to define the most common anatomic location and mechanism for hiatal failure to inform technical strategies to decrease recurrence rates. METHODS Retrospective chart review and video analysis were performed for all recurrent hiatal hernia operations performed by a single surgeon between January 2013 and April 2020. Hiatal recurrences were defined by anatomic quadrants. Recurrences on both left and right on either the anterior or posterior portion of the hiatus were simply classified as 'anterior' or 'posterior', respectively. Three or more quadrants were defined as circumferential. Mechanism of recurrence was defined as disruption of the previous repair or dilation of the hiatus. RESULTS There were 130 patients to meet criteria. Median time to reoperation from previous hiatal repair was 60 months (IQR19.5-132). First-time recurrent repairs accounted for 74%, second time 18%, and three or more previous repairs for 8% of analyzed procedures. Mesh had been placed at the hiatus in a previous operation in 16%. All reoperative cases were completed laparoscopically. Video analysis revealed anterior recurrences were most common (67%), followed by circumferential (29%). There were two with left-anterior recurrence (1.5%), two posterior recurrence (1.5%), and one right-sided recurrence. The mechanism of recurrence was dilation in 74% and disruption in 26%. Disruption as a mechanism was most common in circumferential hiatal failures. Neither the prior number of hiatal surgeries nor the presence of mesh at the time of reoperation correlated with anatomic recurrence location or mechanism. Reoperations in patients with hiatal disruption occurred after a shorter interval when compared to hiatal dilation. CONCLUSION The most common location and mechanism for hiatal hernia recurrence is anterior dilation of the hiatus. Outcomes following techniques designed to reinforce the anterior hiatus and perhaps to prevent hiatal dilation should be explored.
Legacies of Crime: A Follow-Up of the Children of Highly Delinquent Girls and Boys

Legacies of Crime explores the lives of seriously delinquent girls and boys in the United States who were followed over a twenty-year period as they grew to adulthood. In-depth interviews with these women and men and their children - a majority now adolescents themselves - depict the adults' economic and social disadvantages and continued criminal involvement, and in turn the unique vulnerabilities of their children. Giordano identifies family dynamics that foster the intergenerational transmission of crime, violence, and drug abuse, rejecting the notion that such continuities are based solely on genetic similarities or even lax, inconsistent parenting. The author breaks new ground in directly exploring - and in the process revising - the basic tenets of classic social learning theories, and confronting the complications associated with the parent's gender. Legacies of Crime also identifies factors associated with resilience in the face of what is often a formidable package of risks favoring intergenerational continuity.
Applications of Groundwater Quality Models

In the application of mathematical models to practical groundwater pollution problems, the following steps should be included:
Cross-formational flow and salinity sources inferred from a combined study of helium concentrations, isotopic ratios, and major elements in the Marshall aquifer, southern Michigan

Helium data and major ion chemistry are presented for the shallow Marshall aquifer in southern Michigan. This data set is subsequently analyzed in conjunction with major element data sets from deeper and shallower water levels previously collected in this area. He excesses and isotopic ratios suggest the presence of tritiogenic 3He in young waters in the Marshall aquifer. He excesses in old groundwater samples are mostly of crustal origin although the presence of a significant mantle He component in some samples cannot be ruled out. He excesses in the Marshall aquifer are unusually high for such shallow depths (≤300 m) and reach over two and three orders of magnitude above those of air-saturated water (ASW) for 3He and 4He, respectively. He isotopes require a source external to the aquifer, partly supplied by underlying formations within the sedimentary sequence, partly from the crystalline basement. Calibration of He concentrations observed in the Marshall aquifer requires He fluxes of 1 × 10−13 and 1.6 × 10−6 cm3 STP cm−2 yr−1 for 3He and 4He, respectively. These He fluxes are far greater than those reported in other sedimentary basins around the world (e.g., Paris Basin, Gulf Coast Basin) at similar and far greater depths. Such high He fluxes present at such shallow depths within the Michigan Basin strongly suggest the presence of a dominant vertical water flow component and further indicate that impact of recharge water at depth is minor. Upward cross-formational flow is also likely responsible for the extremely high salinities present in the shallow subsurface of the Michigan Basin. The observed positive correlation between helium and bromide strongly suggests that these two very distinct conservative tracers both originate at greater depths and further suggests that advection is the dominant transport mechanism within the basin. The occurrence of large-scale cross-formational flow is also consistent with the evolution displayed by the major ion chemistry throughout most of the sedimentary sequence, indicating that solutes from shallow levels carry the signature of deep formation brines.
Mannosyltransferase activity in calf pancreas microsomes. Formation from guanosine diphosphate-D-(14C)mannose of a 14C-labeled mannolipid with properties of dolichyl mannopyranosyl phosphate.

Abstract Calf pancreas microsomes incorporated radioactive mannose from GDP-d-[14C]mannose into products precipitated by 6 % trichloroacetic acid-0.5 % phosphotungstic acid. This incorporation was maximally stimulated by 10 mm Mn2+ ions and showed a broad pH optimum of 6.0 to 6.7 in Tris-maleate buffer. Between 70 and 90 % of the radioactivity was found in products soluble in chloroform-methanol (2:1, v/v). The rates of labeling of the chloroform-methanol extract and of the residual precipitate were constant for 10 and 30 min, respectively. The chloroform-methanol extract from rough microsomes incubated with GDP-d-[14C]mannose contained a single 14C-labeled product, which was stable under weak alkaline conditions and yielded [14C]mannose upon mild acid hydrolysis and some [14C]mannosyl phosphate upon hot alkaline treatment. It co-chromatographed on silica gel thin layer plates with authentic dolichyl α-d-mannopyranosyl phosphate in seven solvent systems, and could be clearly separated from authentic P1-dolichyl P2-α-d-mannopyranosyl pyrophosphate and from authentic ficaprenyl α-d-mannopyranosyl phosphate, a mannolipid having a shorter polyprenol moiety. The [14C]-mannolipid did not undergo hydrogenolysis during catalytic hydrogenation under conditions which released [14C]mannosyl phosphate from allylic polyprenyl mannosyl phosphates. Thus the mannolipid formed from endogenous lipid is very similar to authentic dolichyl α-d-mannopyranosyl phosphate. Dolichyl phosphate, ficaprenyl phosphate, and solanesyl phosphate (and to a limited extent retinyl phosphate) acted as exogenous acceptors of d-mannose from GDP-d-[14C]mannose in the presence of 0.1 % Triton X-100 to yield the corresponding labeled polyprenyl mannosyl phosphates. The lipid formed from dolichyl phosphate could not be separated from that formed from endogenous lipid, and, like the pancreatic mannolipid, it did not undergo hydrogenolysis. The different mannolipids formed from the exogenous polyprenyl phosphates could be clearly distinguished from one another on thin layer chromatograms, which separated polyprenyl mannosyl phosphates according to the length of their lipid moieties.
Misuse of High-Stakes Test Scores for Evaluative Purposes: Neglecting the Reality of Schools and Students

The article examines high-stakes test scores in Washington, DC that are used to evaluate school quality for AYP purposes. On the basis of analyses of school scores in terms of subpopulations and neighborhood income, it is found that there are, district-wide, significant correlations between test results and students’ economic status, special education status, and English language proficiency. Furthermore, there is evidence that schools with a majority of students considered to be economically disadvantaged experience more pervasive testing failure. These findings contradict the premise of NCLB that we ought to ignore differences in student factors when evaluating instructional quality. The article suggests that while test scores may provide useful information regarding a given school, they are not valid for accountability purposes.
Synthesis of microporous transition-metal-oxide molecular sieves by a supramolecular templating mechanism

Mesoporous bulk1,2,3,4 and thin-film5,6,7 silicates with pore sizes of 20–100 A can be synthesized by using micellar aggregates of long-chain organic surfactant molecules as templates to direct the structure of the silicate network. Because of the potential applications of these molecular-sieve materials as catalysts, separation membranes and components of sensors, it is desirable to extend the range of accessible pore sizes and material compositions. Mesoporous oxides in which transition metals partially8 and fully9,10,11,12,13 substitute for silicon have been made by similar means, in the latter case by ensuring strong interactions between the surfactants and the transition-metal alkoxide precursors. Templating with organic molecules has also been long used for the synthesis of microporous materials—synthetic zeolites—which have smaller pore sizes (4–15 A), but here the organic molecules are shorter-chain amphiphiles which are too small to be considered true surfactants and so act as discrete entities around which the framework crystallizes14,15,16. Here we show that even such short-chain molecules can aggregate into supramolecular templates when they form bonds with transition-metal (niobium) alkoxides, and that in this way they can direct the formation of transition-metal oxides with pore sizes of less than 20 A. These pore sizes, which result from the smaller diameter of micellar structures of the short-chain amines relative to the longer-chain surfactants used for the synthesis of mesoporous materials, qualify the resulting molecular sieves as microporous, even though the supramolecular templating mechanism is similar to that used to make the mesoporous materials. Thus our approach extends the supramolecular templating method to afford microporous transition-metal oxides.
Use of transdermal oxybutynin in individuals with spina bifida

Oxybutynin (OXY) used in combination with clean intermittent catheterisation (CIC), has been the first-line medication for treatment of neurogenic bladder dysfunction over the past two decades. The efficacy of oral OXY in treatment of neurogenic bladder has been demonstrated in several studies. OXY has been shown to increase the maximum bladder capacity, decrease the maximum detrusor pressure with filling, and in combination with CIC, help prevent upper urinary tract deterioration. Until recently, OXY was only available in immediate-release tablets and syrup, both usually requiring dosing two or three times daily, with increased opportunity for missed doses. Intravesical OXY has been used with refractory patients or individuals who could not tolerate the systemic anti-cholinergic side effects, and has been shown to be effective. However, other problems including noncompliance, difficulty with instillation, leakage of medication, etc. have limited its general appeal. With the advent of a long-acting OXY preparation (Ditropan XL), OXY could be given orally just once daily with reduced side-effects for many patients. Even more recently, a transdermal OXY (Oxytrol) delivery system has been tested, FDA-approved and marketed in the United States. A randomised, double-blind, study of transdermal OXY versus immediate-release oral OXY in patients with urge incontinence showed comparable efficacy with lower side effects (Davila 2001).
Efficiency in Visual Scanning by Children with and without Visual Disabilities

Visual scanning behavior and scanning efficiency of children between the ages of 3.5 and 10 years was studied. Twenty-two children with visual disabilities and 25 children without visual disabilities visually searched a line drawing and identified objects as the examiner recorded the objects named. A scan path was then constructed and scanning efficiency was computed by dividing the scan path length by the number of objects named. Significant differences were found between the two groups in the length of the scan path and number of objects reported, but no significant differences were found in scanning efficiency. There was no evidence that coordinated binocular eye movements are correlated with the ability to scan and identify objects.
Abdominal Complications After Heart Surgery

Background Up to 3% of patients undergoing heart surgery suffer from an intraabdominal complication (IAC). These complications carry a high mortality besides adding to the morbidity and cost. This review was undertaken to see if a subset of patients with increased risk of IAC could be identified. Methods Medical records of 7,731 consecutive patients undergoing heart surgery in a single center were screened for identification of postoperative IAC. One hundred and twenty (120) cases were found. One hundred and six (106) cases were compared with the same number of matched controls. Results Significant predictors of the development of IAC were increased cardiopulmonary bypass times (> 99 minutes), peripheral vascular disease, chronic steroid use, and low left ventricular ejection fraction. Patients on postoperative antiplatelet therapy or warfarin had a lower risk of IAC. Significant predictors of mortality in IAC were increased cardiopulmonary bypass times (≥ 120 minutes.), use of inotropes, cerebral vascular disease, and incremental age. Conclusions A subset of patients can be identified who are at higher risk for IAC and an associated adverse outcome. Patients who have prolonged cardiopulmonary bypass, have a low left ventricular ejection fraction, are on steroids, and suffer from other vascular disease should be observed carefully for development of IAC. Postoperative anticlotting strategies may be helpful. Early diagnosis and intervention are essential for improving outcomes in cases of IAC.
The sock matching problem

When matching socks after doing the laundry, how many unmatched socks can appear in the process of drawing one sock at a time from the basket? By connecting the problem of sock matching to the Catalan numbers, we give the probability that k unmatched socks appear. We also show that, for each fixed k, this probability approaches 1 as the number of socks becomes large enough. The relation between the number of socks and the k for which a given probability is first reached is also discussed, but a complete answer is open. In any load of clothes to be washed by a college student, there are inevitably a variety of socks tossed in with all the other garments. By the time the clothes come out of the dryer, the socks have been thoroughly mixed in, hiding underneath shirts or in pant legs. The game of matching then begins: does the sock you just picked randomly out of the pile match any of the others you’ve already removed from the pile? How big is your stack of unmatched socks going to get? This creates a scenario in which there can be k unmatched socks out of n pairs. We wish to determine the likelihood of obtaining a maximum of k unmatched socks while folding a pile of laundry containing the n pairs of socks. We assume that each pair of socks is complete and unique, and that socks are drawn randomly, one at a time. 2. Background
Midsummer metabolism of an eelgrass community

Abstract Eelgrass (Zostera marina) is the dominant member of an important intertidal ecosystem found in many parts of the world. In this preliminary study the metabolism of the entire eelgrass community, including epiphytic plants and other organisms, has been measured in Great South Bay on Long Island, New York. In July it is in equilibrium and consumes as much oxygen as it produces, but in August both photosynthesis and respriation are reduced, with a net increase in oxygen production. This is due largely to the rapid growth of epiphytes during that month.