cssi/SciSciGPT-SciSciNet huggingface dataset:
The Treatment of Peri-Rectal Abscesses for the Emergency General Surgeon

Peri-rectal abscesses are a common problem faced by the emergency general surgeon. Most cases are straightforward and require only simple incision and drainage. However, certain anatomical factors and patient-related comorbidities can increase the complexity of the management of peri-rectal abscesses. This chapter will describe the anatomy of the peri-rectal spaces where abscess can occur and provide a framework to help determine which situations can be treated with a simple incision and drainage and which situations may require further imaging evaluation or alternate approaches to drainage.
Interval Optimization for Available Transfer Capability Evaluation Considering Wind Power Uncertainty

In deregulated electricity markets, available transfer capability (ATC) provides valuable information for market participants, because ATC indicates the remaining amount of power that can be transferred between different areas over already committed capacity. Under the paradigm of renewable power with uncertainty, it is reasonable to apply probabilistic ATC evaluation. However, the probabilistic distribution of uncertainty is not always readily available. In this paper, an interval optimization-based model is proposed for ATC evaluation that only requires the bounds of uncertainty without the precise data of wind power probabilistic distribution. The purpose of introducing interval optimization is to determine the possible ATC range considering wind power uncertainty. In the proposed method, the original interval-based model is first decomposed into a lower boundary (optimistic) model and an upper boundary (pessimistic) model. Then, strong duality theory and a big-M algorithm are applied to convert the combinatorial max-min problem in the pessimistic model to a single level maximization problem for efficient calculations. The proposed methodology is implemented on the PJM 5-bus and IEEE 118-bus systems. Simulation results validate its effectiveness.
Bargaining Chains

We consider a firm that designs a new product and wishes to bring it to market but does not have ownership or control over all of the resources required to make that happen. The firm must select and contract with one of several possible tier 1 suppliers for necessary inputs, who do the same with their (tier 2) suppliers, etc. This general situation is common in industry. We assume tier-wise negotiations, sole sourcing within each tier, complete local information, and horizontal competition. We develop a bargaining-based solution to the negotiations between two adjacent multifirm tiers and show its consistency with familiar solution concepts from the theories of bargaining and cooperative games. We then link up multiple bargaining modules to generate chainwide predictions for efficiency and profitability in supply chains with an arbitrary number of tiers and an arbitrary number of firms per tier. We investigate the implications of the results for investments in process improvements or supplier development.
The Impact of Child Care Subsidies on Mothers’ Education Outcomes

The federal child care subsidy program reduces child care costs for eligible low-income families to facilitate parental employment and educational attainment. Using national data from the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B), this study is the first to ask whether subsidies induce an increase in maternal education level over time, and if so, whether this increase is steeper for mothers who use subsidies to increase their education when their children are younger. After matching subsidy recipients with subsidy-eligible non-recipients on a range of background variables, we assess whether mothers increase their education levels in response to entry into the subsidy program at two different points in a child’s early years: first when children are 2 years old and then when children are in preschool. Results suggest that subsidy receipt promotes mothers’ educational attainment, with the largest impacts for mothers who receive subsidies when their children are younger (2 years old vs preschool-age) and for subgroups of mothers who have low baseline levels of education (high school or below) and who are not initially enrolled in school.
Atlantic Tarpon (Megalops atlanticus) exhibit upper estuarine habitat dependence followed by foraging system fidelity after ontogenetic habitat shifts

Abstract Fish can have complex life histories and use multiple habitats and resources during different life stages. Consequently, their complete life histories are often poorly understood. Atlantic Tarpon (Megalops atlanticus) is an ecologically and economically important sport fish, yet little is known about its lifelong habitat and resource use. We used stable isotope analysis of eye lens δ13C and δ15N to explore patterns in trophic history and habitat use of 16 Atlantic Tarpon from west-central Florida and Louisiana. The stable isotope chronologies indicated dependence on upper estuarine habitats during the early life history, and an ontogenetic shift to coastal waters at approximately 10 years of age and 140 cm total length. During the coastal phase, Atlantic Tarpon displayed among-individual variability and within-individual consistency in basal-resource dependence. Our study highlights the importance of upper estuarine habitats to the early life stages of Atlantic Tarpon, as well as the possibility that adults show fidelity to coastal systems for feeding and growth.
Reprogramming the epigenome with vitamin C

The erasure of epigenetic modifications across the genome of somatic cells is an essential requirement during their reprogramming into induced pluripotent stem cells (iPSCs). Vitamin C plays a pivotal role in remodeling the epigenome by enhancing the activity of Jumonji-C domain-containing histone demethylases (JHDMs) and the ten-eleven translocation (TET) proteins. By maintaining differentiation plasticity in culture, vitamin C also improves the quality of tissue specific stem cells derived from iPSCs that are highly sought after for use in regenerative medicine. The ability of vitamin C to potentiate the activity of histone and DNA demethylating enzymes also has clinical application in the treatment of cancer. Vitamin C deficiency has been widely reported in cancer patients and has recently been shown to accelerate cancer progression in disease models. Therapies involving high-dose vitamin C administration are currently gaining traction in the treatment of epigenetic dysregulation, by targeting aberrant histone and DNA methylation patterns associated with cancer progression.
Classification of Aortic Stenosis Using Time–Frequency Features From Chest Cardio-Mechanical Signals

Objectives: This paper introduces a novel method for the detection and classification of aortic stenosis (AS) using the time-frequency features of chest cardio-mechanical signals collected from wearable sensors, namely seismo-cardiogram (SCG) and gyro-cardiogram (GCG) signals. Such a method could potentially monitor high-risk patients out of the clinic. Methods: Experimental measurements were collected from twenty patients with AS and twenty healthy subjects. Firstly, a digital signal processing framework is proposed to extract time-frequency features. The features are then selected via the analysis of variance test. Different combinations of features are evaluated using the decision tree, random forest, and artificial neural network methods. Two classification tasks are conducted. The first task is a binary classification between normal subjects and AS patients. The second task is a multi-class classification of AS patients with co-existing valvular heart diseases. Results: In the binary classification task, the average accuracies achieved are 96.25% from decision tree, 97.43% from random forest, and 95.56% from neural network. The best performance is from combined SCG and GCG features with random forest classifier. In the multi-class classification, the best performance is 92.99% using the random forest classifier and SCG features. Conclusion: The results suggest that the solution could be a feasible method for classifying aortic stenosis, both in the binary and multi-class tasks. It also indicates that most of the important time-frequency features are below 11 Hz. Significance: The proposed method shows great potential to provide continuous monitoring of valvular heart diseases to prevent patients from sudden critical cardiac situations.
A Technique for the Experimental Determination of the Length and Strength of Adhesive Interactions Between Effectively Rigid Materials

To describe adhesion between bodies of known arbitrary shape and known elastic properties, contact mechanics models require knowledge or assumptions of a minimum of two parameters, the strength of the adhesive interaction (characterized by the intrinsic work of adhesion W adh,int) and the length scale of the interaction (described by the range of adhesion z 0). One parameter can easily be measured if the other is estimated or assumed, but experimental techniques for determining both simultaneously are lacking. Here, we demonstrate a novel technique—called the Snap-in/pull-off Numerical Adhesion Parameter method—for experimentally determining both parameters simultaneously using adhesion measurements performed with an atomic force microscope probe whose geometry has been characterized. The method applies to materials that approach the rigid limit (high elastic moduli). The technique is explained and validated analytically for simple shapes (flat punch, paraboloid, and right cone), and trends in results are compared against prior literature. This approach allows calculation of the adhesion parameters to enable prediction of adhesion behavior, including for advanced technology applications.
How Significant Is Severe Hypoglycemia in Older Adults With Diabetes

Severe hypoglycemia is a devastating event in the lives of people with diabetes treated with insulin and/or insulin secretogogues. Severe hypoglycemia is defined as an episode in which the person with diabetes requires the assistance of another to increase blood glucose, usually by administration of glucagon or contacting a medical professional. These occurrences are not rare. More than 10% of adult patients in the T1D Exchange registry reported at least one episode of severe hypoglycemia over the past 12 months (1). These events elicit profound fear in patients with diabetes. By depriving the brain of glucose, severe hypoglycemia acutely alters brain function, resulting in neuroglycopenic symptoms, seizures, or even death. The impact extends beyond the acute event. The Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation (ADVANCE) trial reported that patients with type 2 diabetes who experience severe hypoglycemia were at higher risk for a major macrovascular event or death over the subsequent 12 months (2). As the population ages, there remains a critical need to understand the significance and impact of severe hypoglycemia in older patients with diabetes. In this issue of Diabetes Care , complementary articles provide new insights into the consequences of severe hypoglycemia in older adults. Lacy et al. (3) report that severe hypoglycemia is associated with reduced cognitive function in older adults with type 1 diabetes, and Standl et al. (4) confirm the bidirectional nature of the association between severe hypoglycemia and cardiovascular (CV) events in adults with type 2 diabetes. Both investigations …
A trial of vaccination with the carcinoembryonic antigen (CEA) peptide CAP 1–6D with montanide ISA 51 adjuvant or granulocyte- macrophage colony stimulating factor (GM-CSF) in HLA-A2+ patients with CEA producing adenocarcinomas of gastrointestinal (GI) track

13513 Advances in drug therapy have improved the survival of patients with GI tumors but most patients with metastatic disease are not cured. Immunotherapy is an additional modality of treatment. I...
On three-dimensional stable long-wavelength convection in the presence of Dirichlet thermal boundary conditions

It is a well-known fact that the onset of Rayleigh–Benard convection occurs via a long-wavelength instability when the horizontal boundaries are thermally insulated. The aim of this paper is to quantify the exact dimensions of a cylinder of rectangular cross-section wherein stable three-dimensional Rayleigh–Benard convection sets in via a long-wavelength instability from the motionless state at the same value of the critical Rayleigh number as the corresponding horizontally unbounded problem when the bounding horizontal walls have infinite thermal conductance. Hence, we consider three-dimensional Rayleigh–Benard convection in a cell of infinite extent in the x-direction, confined between two vertical walls located at $$y= \pm H$$ and horizontal boundaries located at $$z=0$$ and $$z=d$$ . Our analysis predicts the existence of the sought stable state for experimental velocity boundary conditions at the vertical walls provided the aspect ratio $$\delta = H/d$$ takes a certain value. In the limit $$H \rightarrow \infty $$ , we retrieve the stability characteristics of the horizontally unbounded problem. As expected, the analysis predicts two counter-rotating rolls aligned along the y-direction of period $$2 \pi /\delta $$ equal to the period of the roll in the y-direction of the corresponding unbounded problem. A long-scale asymptotic analysis leads to the derivation of an evolution partial differential equation (PDE) that is fourth order in space and contains a single bifurcation parameter. The PDE, valid for a specific value of $$\delta $$ , is analyzed analytically and numerically as function of the bifurcation parameter and for a variety of velocity boundary conditions at the vertical walls to seek the stable steady-state solutions. The same analysis is also extended to the case of convection in a fluid-saturated porous medium.
Hallmarks of primary neurulation are conserved in the zebrafish forebrain

Primary neurulation is the process by which the neural tube, the central nervous system precursor, is formed from the neural plate. Incomplete neural tube closure occurs frequently, yet underlying causes remain poorly understood. Developmental studies in amniotes and amphibians have identified hingepoint and neural fold formation as key morphogenetic events and hallmarks of primary neurulation, the disruption of which causes neural tube defects. In contrast, the mode of neurulation in teleosts has remained highly debated. Teleosts are thought to have evolved a unique mode of neurulation, whereby the neural plate infolds in absence of hingepoints and neural folds, at least in the hindbrain/trunk where it has been studied. Using high-resolution imaging and time-lapse microscopy, we show here the presence of these morphological landmarks in the zebrafish anterior neural plate. These results reveal similarities between neurulation in teleosts and other vertebrates and hence the suitability of zebrafish to understand human neurulation. Jonathan Werner, Maraki Negesse et al. visualize zebrafish neurulation during development to determine whether hallmarks of neural tube formation in other vertebrates also apply to zebrafish. They find that neural tube formation in the forebrain shares features such as hingepoints and neural folds with other vertebrates, demonstrating the strength of the zebrafish model for understanding human neurulation.
Effects of Norepinephrine Infusion on Cutaneous Surface Temperatures of the Distal Extremities.

OBJECTIVES The etiology of vasopressor-induced digital necrosis is poorly understood, but the skin changes resemble those of frostbite, and it is known from experience that patients taking vasopressors have decreased digital temperatures. We aimed to examine the effects of norepinephrine use on surface temperatures of the distal extremities because there have been no studies examining this relation. METHODS Surface temperatures of all digits, palms, and soles were measured using an infrared thermometer in patients receiving different rates of norepinephrine infusion in the intensive care unit and compared with those not receiving any vasopressors. RESULTS A total of 101 measurements from 41 unique individuals were obtained. Temperature gradients between the core and the fingertips were consistently more pronounced in those receiving norepinephrine compared with those not receiving norepinephrine and increased with increasing rates of norepinephrine infusion, except with high-dose norepinephrine. Temperature gradients were more pronounced in the toes. CONCLUSIONS Norepinephrine use was associated with greater core-to-fingertip temperature gradients and were more pronounced in the toes compared with the fingers.
Trends and Outcomes of Surgical Re-exploration Following Cardiac Operations in the United States

Abstract Background Surgical re-exploration following cardiac surgery has been associated with increased in-hospital complications and mortality in limited series. The present study examined trends in reoperation and its impact on clinical outcomes and resource use in a nationally-representative cohort. We sought to determine patient and hospital factors associated with re-exploration and reoperative mortality, defined as failure-to-rescue-surgical (FTR-S). Methods Adult hospitalizations entailing cardiac operations (coronary artery bypass and/or valve) were identified using the 2005-2018 National Inpatient Sample. Procedures were tabulated using International Classification of Diseases codes. Hospitals were ranked into tertiles according to risk-adjusted mortality, with the lowest stratified as high-performing. Multivariable regression models examined factors associated with re-exploration as well as clinical outcomes including FTR-S and resource utilization. Results Of an estimated 3,490,245 hospitalizations, 78,003 (2.23%) required re-exploration with decreasing incidence over time. Valvular procedures, preoperative intra-aortic balloon pump and liver disease were associated with greater likelihood of re-exploration. Reoperation was associated with increased odds of mortality (adjusted odds ratio (AOR): 3.86, 95%CI: 3.61-4.12), perioperative complications and resource utilization. Increasing time from index operation to re-exploration was associated with higher odds of mortality (AOR:1.10/day, 95%CI: 1.07-1.12). High-performing hospitals were associated with lower odds of re-exploration (AOR: 0.88, 95%CI: 0.82-0.95) and FTR-S (AOR: 0.29, 95%CI: 0.23-0.35). Conclusions Surgical re-exploration following cardiac surgery has declined over time. High performing hospitals demonstrated lower rates of re-exploration and subsequent failure-to-rescue. Although unable to identify specific practices, our study highlights the presence of significant variation in takeback rates and further study of underlying factors is warranted.
Mixed-mode fracture in a soft elastomer

Abstract We present an experimental study on mixed-mode crack propagation in thin sheet specimens of a soft silicone elastomer. To introduce mixed-mode loading, we adopted the widely applied pure shear fracture testing geometry, but oriented the initial crack at an inclined angle relative to the direction perpendicular to the external tensile loading. Because of the inclined angle, locally the crack tip was subjected to both tensile and shear loading even though the global loading was tensile, thus resulting in a mixed Mode-I and Mode-II condition for the crack. Altering the inclined angle led to different degrees of mode-mixity and hence different crack propagation trajectories. Using a particle tracking method, we were able to measure the nonlinear deformation fields throughout the entire course of crack propagation. Based on the measured deformation fields, we used J-integral to calculate the energy release rate during crack propagation and found that the results were insensitive to the tangent direction of the crack trajectory, suggesting that the fracture toughness was approximately mode independent. Moreover, the tangent direction of the crack trajectory, when plotted in the reference configuration, was observed to be perpendicular to the direction of maximum principal stretch. The experimental results pave the way for establishing quasi-static mixed-mode fracture criteria for soft silicone elastomer, which has not yet been well understood in the literature.
Making the World a Better Place for Families: The Power of One

There are three important factors to consider in respect to protecting the family. First, this is a time of great opportunity for the family, but it is also a dangerous time. We must recognize and face the dangers that the family faces and not let the great opportunities blind us from the dangers that lurk. Secondly, same-sex marriage must be evaluated. Marriage is the core institutional foundation of society and when marriage and marital families disintegrate, societies and individuals suffer and struggle. Redefining marriage in the law or within societies viewpoint can profoundly impact our lives. Third, the power of one is formidable. Each one of us can and must be actively engaged in protecting marriage and the family within our nation, states, communities and homes. Legal scholars are obligated to speak out in regards to social issues and institutions such as marriage and the marital family.
Increased circulating cholecystokinin in obstruction-induced acute pancreatitis. I. Bile duct obstruction with and without pancreatic duct obstruction.

Abstract Bile exclusion from the gut exacerbates pancreatic duct obstraction-induced acute pancreatitis. We hypothesized that obstruction-induced acute pancreatitis involves an increase in circulating cholecystokinin (CCK), as bile and pancreatic juice exclusion from the gut stimulates duodenal CCK release. We studied 54 rats after the following operations: (1) sham operation ( n = 18). (2) hepatic bile duct obstruction alone ( n = 18), (3) hepatic bile duct and common bile-pancreatic duct obstruction ( n = 18). Rats recovered and were killed in subgroups of six rats each at 3.6. and 18 hr after operation; blood was collected for measurement of plasma CCK and amylase concentrations. Each pancreas was excised, weighed, and processed for histological examination; an acute pancreatitis score was determined. Combined bile and pancreatic duct obstruction induced acute pancreatitis and was associated with a marked increase of circulating CCK concentration. Bile duct obstruction alone did not induce acute pancreatitis but was associated with an increase of circulating CCK of lower magnitude. The time course of circulating CCK increase showed an early peak. These findings support our hypothesis and suggest that CCK plays a role in the pathogenesis of obstruction-induced acute pancreatitis.
Review of Frank Ryan’s Book: Darwin's Blind Spot: Evolution beyond Natural Selection

Competing bacteria can fine tune their weapons to such an extent that they may win over their victims. They could be invited into their conquered host cells and become organelles like mitochondria and the cell nucleus. But the illusion of conquest is short lived. As the competing prokaryote cells find themselves to be one eukaryote cell, they discover a deeper symmetry and their felt imperatives flip as the competing bacterium find deep agreements in their mutual cooperation. Frank Ryan's book presents a wonderful account of such symbiosis as discovered in biological evolution. You can find this book at Amazon: Darwin's Blind Spot: Evolution beyond Natural Selection .
Stroke in Estrogen Receptor-α–Deficient Mice

Background and Purpose —Recent evidence suggests that endogenous estrogens or hormone replacement therapy can ameliorate brain damage from experimental stroke. Protective mechanisms involve enhanced cerebral vasodilation during ischemic stress as well as direct preservation of neuronal viability. We hypothesized that if the intracellular estrogen receptor subtype-α (ERα) is important to estrogen’s signaling in the ischemic brain, then ERα-deficient (knockout) (ERαKO) female mice would sustain exaggerated cerebral infarction damage after middle cerebral artery occlusion. Methods —The histopathology of cresyl violet–stained tissues was evaluated after reversible middle cerebral artery occlusion (2 hours, followed by 22 hours of reperfusion) in ERαKO transgenic and wild-type (WT) mice (C57BL/6J background strain). End-ischemic cerebral blood flow mapping was obtained from additional female murine cohorts by using [14C]iodoantipyrine autoradiography. Results —Total hemispheric tissue damage was not altered by ERα deficiency in female mice: 51.9±10.6 mm3 in ERαKO versus 60.5±5.0 mm3 in WT. Striatal infarction was equivalent, 12.2±1.7 mm3 in ERαKO and 13.4±1.0 mm3 in WT mice, but cortical infarction was paradoxically smaller relative to that of the WT (20.7±4.5 mm3 in ERαKO versus 30.6±4.1 mm3 in WT). Intraocclusion blood flow to the parietal cortex was higher in ERαKO than in WT mice, likely accounting for the reduced infarction in this anatomic area. There were no differences in stroke outcomes by region or genotype in male animals. Conclusions —Loss of ERα does not enhance tissue damage in the female animal, suggesting that estrogen inhibits brain injury by mechanisms that do not depend on activation of this receptor subtype.
Micron-resolution 3-D measurement of local orientations near a grain-boundary in plane-strained aluminum using X-ray microbeams

Abstract X-ray microbeams have been used to perform nondestructive measurements of the local orientations and microstructure in single-crystal and grain-boundary regions in a columnar Al (0.2 wt.% Mg) tri-crystal deformed 20% in plane-strain. The measurements were made using a recently developed differential-aperture X-ray microscopy (DAXM) technique providing high angular resolution determinations of local orientations with micron 3-D spatial resolution using focused microbeams. The X-ray microbeam technique is described, three-dimensional spatially resolved pole-figures and lattice rotation distributions in single-crystal and grain-boundary regions are presented, and the potential of micron resolution 3-D X-ray structural microscopy for plastic deformation investigations is discussed.
Spirituality in Music Education: Transcending Culture, Exploration III.

Spirituality and religion are not synonymous and, in fact, require not only different definitions but also appropriate vocabulary. A deeper discussion of the issues concerning spirituality ensues in several sections: 1) fundamental differences between spirituality and religion; 2) brain operations relative to transcendent states; 3) a definition of consciousness; 4) music, culture, and transcendence; 5) transcendence; 6) transcendence through music, and 7) spirituality in music education. The last section contains several recommendations on how spirituality can be embraced by music educators and included in the curriculum to enhance the worldview of students.
Pilot Study of Aromatic Hydrocarbon Adsorption Characteristics of Disposable Filtering Facepiece Respirators that Contain Activated Carbon

Disposable filtering facepiece respirators (FFRs) used by health care workers are not designed to reduce the inhalation of volatile organic compounds (VOCs). Smoke-generating surgical procedures release VOCs and have been associated with the following complaints: foul smell, headaches, nausea, irritated throat and lungs, and asthma. Organic vapor FFRs that contain activated carbon are used by industrial workers to provide odor relief. These respirators remove irritating odors but are not marketed as respirators that provide respiratory protection against a gas or vapor. This study investigated the aromatic hydrocarbon adsorption capabilities of nuisance organic vapor (OV) FFRs. Three OV FFR models were tested to determine the 10% breakthrough time of three aromatic hydrocarbons at ambient room temperature and relative humidity. All respirator models were exposed to each vapor separately in three duplicate tests (n = 27). The respirator was sealed with silicone to an AVON-ISI headform that was placed in a ...
Interventional nutrition for the cancer patient

Dogs and cats with cancer have significant alterations in carbohydrate, protein, and fat metabolism, which can result in cancer cachexia and subsequently can decrease quality of life, reduce response to therapy, and shorten survival time. Nutritional modulation may be beneficial in the treatment of cancer patients to reverse these metabolic alterations. There is evidence that foods relatively low in simple carbohydrates with moderate amounts of high-quality protein, fiber, and fat (especially fats of the omega-3 fatty acid series) are beneficial for pets with cancer. In addition, certain supplemental nutrients may have potential to reduce the risk of developing cancer, or the growth and metastases of established malignant disease. Nutritional intervention can be a powerful tool for controlling malignant disease and for reducing toxicity associated with chemotherapy and radiation therapy.
Three-dimensional materials science

Abstract Two-dimensional metallography has been very successful, but some phenomena must be understood in three dimensions (3D). New experimental and computational methods enable 3D characterization and modeling. Microstructural network analysis can provide insight into various 3D material properties. Because microstructural phase space is large, many important, open questions remain.
Supporting subseries nearest neighbor search via approximation

Searc hingfor nearest neigh b orsin a large set of time series is an importan tdata mining task. This paper studies the following type of time series nearest neighbor queries: Given a query series and a starting time, among all the subseries (of a collection of data series) that have the same length as the query series and start at the given time, nd the K subseries that are closest to the query series. T o support such queries, the paper develops a tec hnique that uses a xed number of values to approximate each whole data series, and obtains the appro ximationof an y required subseries at the query time. The paper then proposes three subseries search algorithms and compares them with the naive method that sequen tially scans the whole data set, as well as a method adapted from a state-of-art subseries search algorithm. Experiments are conducted on both a real-life data set and a synthetic one. Results show that the proposed methods access only a small portion of the precise data and outperform the others in run time.
Genetic Modifiers of Atherosclerosis in Mice

Abstract: Common atherosclerosis has a genetic component, but it is difficult to determine the specific genes that play a role in atherosclerosis susceptibility in humans. We have used the apoE-deficient mouse as a model system to examine the effects of candidate genes on atherosclerosis as well as to perform genomic experiments to map and isolate other genes giving rise to atherosclerosis susceptibility. We have tested the effects of mutations in the MCSF and VCAM-1 genes on atherosclerosis, and in both of these cases mutations led to gene dosage-dependent decreases in atherosclerosis. By successive back breeding, we have established apoE-deficiency on the C57BL/6 and FVB/N inbred mouse strains. Lesions in C57BL/6 mice are about eightfold larger than those in FVB/N mice, and lesions in F1 hybrids are intermediate in size. We have performed quantitative trait locus mapping on two F2 cohorts and discovered atherosclerosis susceptibility loci on chromosomes 10, 14, and 19.
UPTAKE OF DEUTERIUM INTO PROTEINS OF FERTILIZED AND UNFERTILIZED ARBACIA EGGS SUSPENDED IN HEAVY WATER

When fertilized and unfertilized eggs of Arbacia punctulata are suspended in heavy water, deuterium is incorporated into stable positions in the egg proteins. The rate of incorporation of the isotope is considerably greater in fertilized than in unfertilized eggs, and is accelerated at the time of formation of the blastula. The result of calculation of the maximum deuterium concentration which would be reached on complete turnover indicates that at least one out of every ten stably bound hydrogen atoms of the egg proteins is a deuterium atom. This has been interpreted as evidence that at the time of formation of the sea urchin blastula and in the period of development which follows, synthesis and breakdown are simultaneous processes leading to the redistribution of amino acids among the egg proteins.
Pole tip recession studies of thin-film rigid disk head sliders I. Mechanisms of pole tip recession growth

Abstract Pole tip recession (PTR) results in an increase in spacing between recording elements and magnetic media which is undesirable for high magnetic recording. A methodology for an accurate measurement of PTR using an atomic force microscopy (AFM) was developed. A reliable measurement of PTR with AFM consists of: (1) mounting the sample such that air bearing surface (ABS) is as parallel as possible to fast scan direction, (2) selection of fast scan direction along the long axis of a slider and (3) the use of software correction, namely, zero order flatten and first order plane fit, to remove measurement errors. The inductive head sliders with both initially protruded and recessed poles were used for the investigation of the PTR growth as a function of increasing CSS cycles. CSS tests were conducted using laser textured and mechanically textured disks. Based on AFM measurements, microscopy and chemical analyses of the worn sample, mechanisms of PTR growth were proposed. If the poles are protruded, first, the protruded parts of pole tips are knocked off by harder carbon coated laser bumps through adhesive wear and two-body abrasive wear within initial several hundred CSS cycles. Continued contacts at head-disk interface results in the wear of Al 2 O 3 TiC ABS, Al 2 O 3 insulating film, NiFe poles and carbon coated laser bumps which generates abrasive particles. These wear particles result in three-body abrasive wear which selectively removes relatively soft metal poles and leads to a PTR. PTR growth levels off after a certain number of CSS cycles, dependent upon the pole tip design, typical size of wear particles and propensity of stain growth. Formation of stain on the pole tip region is observed after certain number of CSS cycles which minimizes PTR growth, however, stain build up is undesirable.
Finite-grid instability in quasineutral hybrid simulations

Analysis and simulation of numerical instability caused by the spatial grid is presented for the case of quasineutral hybrid plasma simulation. The simplest case of particle ions advanced in the ambipolar electric field due to an isothermal, charge neutralizing electron fluid is examined. Stationary plasma is destabilized by finite ion temperature with the threshold temperature Ti characterized by the ratio ZTe/Ti , where Z is the charge state of the ions and Te is the electron temperature. A cold drifting plasma is found to be unstable with typical growth rate γ ≈ 0.4-0.6 Cs/Δx (Δx is the grid spacing and Cs is the ion acoustic speed); simulations show that unstable growth is saturated by particle trapping leading to heated ions. For nearest grid point weighting, saturation, and threshold for growth are observed to be Ti ≈ 0.6 ZTe while for linear particle weighting, Ti ≈ 0.1 ZTe. These results are relevant to hybrid particle simulations of laser generated plasmas, a regime where ZTe/Ti ⪢ 1 is encountered.
Invariance Property of the Brillouin-Wigner Perturbation Series

The complete perturbation series for the energy is invariant under the operation of adding a velocity-dependent interaction to the zeroth order Hamiltonian and subtracting the same quantity from the perturbation operator. The same invariance property appear to hold also for an optimum formulation of the terminated energy series generated by the $n\mathrm{th}$ order approximation to the wave function. An explicit proof is given for the first- and second-order wave functions and also for the complete energy series. Variational procedures for determining (a) the optimum velocity dependence of the zeroth order Hamiltonian and (b) the optimum uniform displacement of the zeroth order energy spectrum are discussed in relation to the invariant formulations.
Drug Therapy for Diarrheal Diseases: A Look Ahead

The gastrointestinal tract is involved in both absorption and secretion of electrolytes and water, with absorption as the predominant process. In diarrheal diseases this balance is disturbed, and the result is net secretion. Most of the drugs used for the treatment of diarrhea at least partially act by (1) stimulating absorption only, (2) both stimulating absorption and inhibiting secretion, or (3) inhibiting secretion only. The therapeutic usefulness of an antidiarrheal agent depends on how efficiently it alters secretion and/or absorption and on how few systemic adverse reactions it causes. When more information on the regulation of absorption and secretion has been accumulated, it may be possible to develop new drugs that can be aimed directly at these processes. Advances in drug therapy for diarrheal diseases followed an increased understanding of the pathophysiology of diarrhea. There were two crucial observations: first, that in diarrheal diseases an increased volume of water is lost in stool [1, 2], and second, that in virtually all diarrheal diseases some portion of the gastrointestinal tract is converted from an organ in which overall absorption of water and electrolytes occurs to one in which overall secretion of water and electrolytes occurs. The extra fluid produced overwhelms the absorptive capacity of the gastrointestinal tract distal to the site of secretion, and more water is therefore passed in the stool. Intestinal water transport follows the establishment of osmotic gradients across the intestinal epithelium via the transport of electrolytes and simple products of food breakdown, including sugars and amino acids. Electrolyte absorptive and secretory processes occur simultaneously in the intestine. Normally the absorptive processes predominate, with net absorption of water and electrolytes; however, in diarrheal disease absorption is decreased and/or secretion is increased so that the normal balance is disturbed.
Interdemic variation in the foraging ecology of the African cyprinid, Barbus neumayeri

In the African cyprinid, Barbus neumayeri, populations from hypoxic waters have larger gills than populations from well-oxygenated streams. Differences in trophic morphology and feeding performance between these populations suggest a reduction in feeding efficiency in large-gilled fish that may reflect spatial constraints of the gills. However, this variation may also reflect interdemic variation in diets. In this study, we describe patterns of variation in diet, gut morphology, and prey availability for populations of B. neumayeri from swamp (low-oxygen) and stream (high-oxygen) sites in Kibale National Park, Uganda. Our results indicate that B. neumayeri are omnivorous, feeding primarily on benthic prey items; however, diets differed among swamp and stream sites for certain prey types. The observed dietary differences do not provide direct support for predictions based on variation in trophic musculature; hard-bodied prey were more common in low-oxygen sites. Prey availability also differed among sites; in particular, insect abundance and richness was generally lower in the swamp sites. Gut length was longer in one of the four populations, but did not conform to expectations based on diet differences. Condition and growth rates did not differ between populations from hypoxic and well-oxygenated sites, despite observed differences in prey availability and diet, suggesting that B. neumayeri may be distributed in a way that equalizes fitness among populations in different habitats.
Event status of the Starr-Edwards aortic valve to 20 years : a benchmark for comparison

Abstract Background . Considerable effort and expense has been invested in the evolutionary development of cardiac valvular prostheses with the goal of reducing or minimizing specific events related to these prostheses. It is important to measure any improvement achieved with such development by comparison against a historic standard. The Starr-Edwards caged-ball prosthesis model 1260 has been used for 30 years as the predominant or sole model of its kind for aortic valve replacement. This historic opportunity provides a benchmark for subsequent improvement and comparison of current prostheses. Methods . Between 1969 and 1991, 1,100 patients (median age, 57 years; 838 men and 194 women) underwent aortic valve replacement with or without coronary artery bypass grafting (aortic valve replacement, 964; aortic valve replacement plus coronary artery bypass grafting, 136) with the 1260 Starr-Edwards caged-ball prosthesis. Results . Operative mortality was 6.2% (68 patients). Univariate patient characteristics predictive of early mortality were female sex ( p = 0.003), age (>56 years; p = 0.002), recent operative interval (1985 to 1991 versus 1969 to 1976 or 1977 to 1984; p = 0.002), presence of atrial fibrillation ( p = 0.001), and small valve size (7A to 8A=19 to 21 mm; p p = 0.0001), older age (>56 years; p = 0.0001), and lower ( p = 0.0001). Freedom from thromboemboli and anticoagulant-related bleeding at 5 years was 90.8% and 98.7%, respectively. Univariate model for greater risk of late thromboemboli identified female sex ( p = 0.04), older age (>56 years; p = 0.0002), and New York Heart Association class III or IV ( p = 0.0058), as risk factors. Multivariate analysis for thromboemboli demonstrated older age ( p = 0.0007) and New York Heart Association class III or IV ( p = 0.0041) as significant. Alternatively, univariate analysis for late bleeding found only the most recent operative interval ( p = 0.009) as significant, and the rarity of events prevented a multivariate query. There were no valve failures. Conclusions . The late results of survival and freedom from late anticoagulant-related bleeding or thromboemboli are excellent, especially in larger (9A and above) sizes, and with the long implant record comparable with more recent prostheses, the Starr-Edwards valve provides an excellent, safe, and durable alternative in the aortic position and provides a benchmark against which to compare other prostheses.
Similarity and stability analysis of the two Partitioning type clustering algorithms

The similarity and stability analysis of the two partitioning type clustering algorithms, which appeared in this journal recently, are presented with respect to two different metrics. This article also includes other aspects of the algorithms, such as the number and size of the clusters generated, the similarity between the members of a cluster and the corresponding centroid, and other relevant details. In the experiments, a document collection consisting of the titles, abstracts, and keywords of 167 ACM TODS publications was used.
Investigation of three types of catalysts for the hydration of ethylene oxide (EO) to monoethylene glycol (MEG)

Amine compounds, bi-functional compounds (EDTA, ethylene diamine tetra acetic acid type), and Salen compounds were investigated for catalytic hydration of ethylene oxide (EO) to monoethylene glycol (MEG). Many of the catalysts studied are selective for the formation of MEG compared with thermal hydration without any catalyst present. The results of the catalytic hydration with three types of catalysts were rationalized using acid and base catalyzed reaction mechanisms.
The Band Spectrum of Ionized Aluminum Hydride.

The Sch\"uler hollow aluminum cathode lamp, containing helium and hydrogen, maintained at 2000 volts d.c., has been used to excite the band spectrum of AlH, which has been photographed with a 21-foot grating spectrograph. Among the new systems appearing there is one with principal head at 3632A which on analysis proves to consist of the (0,0) and (1,1) bands of a $^{2}\ensuremath{\Pi} (\mathrm{regular})\ensuremath{\rightarrow}^{2}\ensuremath{\Sigma}^{+}$ system due to Al${\mathrm{H}}^{+}$. The $^{2}\ensuremath{\Pi}$ state is found to be regular and not inverted as suggested by Holst. The various band constants are obtained and the spin and $\ensuremath{\Lambda}$-doubling compared with theory.
Systems approach to the concept of niche

The systems approach to niche presented herein stands as an example of the unifying potential of mathematical system theory when applied to concepts and principles of ecology. Beginning with subjective concepts from the naturalistic tradition, the niche was framed in the formalism of general system theory. So modeled, it appeared as a restriction of a more general construct, the environ. Both niches and environs are implementable in the context of ecosystem models, and with the growing ability of ecologists to construct such models, system theoretic niches and environs both should serve in the future to clarify old problems of ecology, and make it possible to raise new classes of problems. The nature of niches, always difficult conceptually for the ecologist, may now give way to further development, both theoretical and empirical.
Bacterial proteases and adherence of Pseudomonas aeruginosa to mouse cornea

Abstract The goal of this study was to test whether bacterial exoproducts, such as elastase or alkaline protease contribute to the initial binding ofPseudomonas aeruginosato mouse corneal epithelium. Each protease, purified fromP. aeruginosa,when applied exogenously at concentrations of either 25 or 50ngml−1, elevated binding ofPseudomonasto mouse cornea in organ culture. Polyclonal antibodies against bacterial alkaline protease, but not elastase, interfered with bacterial binding and reduced significantly the number of organisms bound to cornea in an organ culture binding inhibition assay. Zymographic analysis of conditioned media from additional organ culture experiments showed that theP. aeruginosastrain used, which is highly virulent in cornea in vivo, secretes detectable levels of alkaline protease, but not elastase in vitro and that secretion was enhanced if the corneal epithelium was wounded. Lastly, how alkaline protease enhanced bacterial binding to the corneal epithelium of the organ cultured eye was examined. Data from this study suggest that exposure of lipase-sensitive epithelial receptors represents at least one mechanism.
Current Definitions of Central Line–Associated Bloodstream Infection: Is the Emperor Wearing Clothes?

Wearing Clothes? • Author(s): Daniel J. Sexton , MD, Luke F. Chen , MBBS, MPH, CIC, FRACP, Deverick J. Anderson , MD, MPH Source: Infection Control and Hospital Epidemiology, Vol. 31, No. 12 (December 2010), pp. 1286-1289 Published by: The University of Chicago Press on behalf of The Society for Healthcare Epidemiology of America Stable URL: http://www.jstor.org/stable/10.1086/657583 . Accessed: 10/06/2011 08:02
A reference effect approach for power analysis in fMRI.

In fMRI, the issues involved in the control of type I error are fairly well understood. In contrast, the control of type II error has received less formal attention. This is perhaps due to the fact that the consideration of type II error requires the specification of an alternative hypothesis/experimental effect. In this paper, we present a method for expressing experimental effects in fMRI in a manner relative to a reference effect. A reference effect is chosen based on its neurophysiological significance to the researcher. This method provides a means to quantitatively express alternative hypotheses for fMRI, thus allowing type II error assessment prior to the collection of fMRI data. The simultaneous control of both type I and type II error should make meaningful interpretations possible from both positive and negative fMRI results.