cssi/SciSciGPT-SciSciNet huggingface dataset:
Boundary layer receptivity - Theory

Abstract : Receptivity processes by which free-stream disturbances generate Tollmien-Schlichting waves in boundary layers have been analyzed using asymptotic methods for high Reynolds numbers. Vortical and acoustic free-stream disturbances have been considered. Receptivity occurs in the vicinity of the leading edge, and in localized regions further downstream where some feature (e. g., a wall hump) produces a short-scale disturbance to the mean flow. Nonlinear effects related to the free-stream pressure field have been found to play an important role in localized receptivity to vortical disturbances. For leading- edge receptivity, the influences of the body nose radius and aerodynamic loading in the leading-edge region have been analyzed. In the absence of aerodynamic loading, an increase in the body nose radius decreases the leading-edge receptivity coefficient. However, strong aerodynamic loading leads to a dramatic increase in the leading-edge receptivity coefficient, negating the decrease due to a larger nose radius. The propagation of an instability wave past a junction between a rigid wall and a surface with non-zero compliance or admittance has also been analyzed. The junction can cause energy to be scattered from the instability wave to higher eigenmodes, effectively attenuating the instability wave.
The total rehabilitation of Graves' ophthalmopathy.

The concept of enlarging the orbital space in some patients with Graves' ophthalmopathy is usually acceptable. Controversial, however, are 1. the indications for enlarging the space, 2. the sequence of therapy that is most successful in restoring the eyes to near normal, and 3. the value of enlarging the orbital space and its relationship to non-surgical alternatives. Since 1969 a personal experience with more than 600 eyes in over 300 patients using the transantral route to orbital decompression has accumulated. From the surgical experience plus exposure to other non-surgically treated patients, a concept of total management of Graves' ophthalmopathy has evolved. The technical aspects of decompression through the sinuses are straight forward. The key to a satisfactory operation is a complete transantral ethmoidectomy; a less than complete ethmoidectomy will eliminate a predictable result. Transantral decompression as a single procedure will not successfully palliate all aspects of Graves' ophthalmopathy. Eye muscles and lid procedures in a timely sequence may be needed to complete rehabilitation. Perfect eyes are seldom obtained but the goal of satisfied patients is realistic. This essay will emphasize technical aspects, theoretical advantages, as well as pitfalls and limitations of the transantral orbital decompression.
Agricultural manipulation of floodplains in the southern Basin and Range Province

Abstract Floodplains in arid lands can be agriculturally productive, but they can also be geomorphically unstable environments. Many of the floodplains of higher order basins in southern portion of the Basin and Range Province of the American Southwest have been farmed intermittently for hundreds of years, and continuously for the past century. In order to be productive, however, these floodplains were modified considerably by human agency. This paper reviews the different types of human manipulations to floodplains that may result in land degradation and geomorphic change, including vegetation, topography, soils, hydrology, and channel banks. Emphasis is on the direct and indirect consequences of geomorphic modification, and the long-term viability of such changes in the contexts of landscape sensitivity and sustainability. Evidence documents transformation of natural floodplains to agricultural surfaces, with examples from southern Arizona, USA, and Sonora, Mexico.
RELATIONSHIPS BETWEEN ELECTRICAL AND PHYSICAL PROPERTIES OF CEMENT PASTES

Abstract Many aspects of mechanical behavior of engineering materials, specifically concrete and soils, can be explained from a knowledge of physico-chemical and/or particle geometry factors. A qualitative measure of the above factors has been used to describe a modelled structure of the cement gel system, and attempts have been made to correlate the engineering properties of hardened cement pastes with their microstructure. This paper presents the results of preliminary investigations which suggest that some of the important mechanical properties of mature cement pastes may be predicted quantitatively from measurements of their electrical properties at early ages.
Coincidence of the promoter and capped 5′ terminus of RNA from the adenovirus 2 major late transcription unit

Abstract During the late stage of adenovirus 2 infection, RNA chains are initiated at a site near coordinate 16 (Evans et al., 1977) and transcribed ∼30,000 nucleotides to the far end of the genome at coordinate 100. Late mRNAs processed from these transcripts contain a common spliced tripartite leader (Berget, Moore and Sharp, 1977; Chow et al., 1977a) encoded at ∼16, 20 and 27, and protein coding sequences which map down-stream. This report maps the late promoter and the capped 5′ end of nuclear and cytoplasmic RNAs from this transcription unit, and analyzes their structures. We show that nascent RNA chains pulse-labeled in vivo are initiated at coordinate 16.5 ± 0.5 and contain the sequences intervening between the leader segments. We map the capped 5′ terminus of late nuclear transcripts at a site between 16.4 and 16.6 by aligning T1 RNAase oligonucleotides from nuclear RNA with the DNA sequence of the promoter region. The structure of the first eleven residues of the capped 5′ terminus of late mRNA was determined by direct RNA sequencing. This structure corresponds exactly to a DNA sequence at coordinate 16.4 and precisely positions the mRNA cap template within the promoter region. These results suggest that the promoter and the cap template sites are coincident, and that the initiating residues of the primary transcript are precursors of the capped 5′ end of mRNA. Residues removed from transcripts by splicing were identified. These plus caps were detected in large polyadenylated nuclear RNA, indicating that capping and polyadenylation can occur on unspliced molecules. Residues retained in the mRNA first leader contain a nine residue sequence adjacent to the cap which is complementary to the 3′ end of 18S rRNA, suggesting that the first leader functions in ribosome binding. Nucleotide sequences from the promoter region are compared with cellular counterparts. Strong homologies at cap sites and splice points suggest that for the noted cases, the virus and cell share closely related mechanisms for mRNA 5′ end synthesis and splicing.
Distortions of time during rapid eye movements.

Illusions of spatial vision can occur during rapid eye movements known as saccades. A new report shows that temporal judgments are also distorted around the time of saccades, suggesting that the neural representations of time and space may be linked.
On Propagated Scoring for Semisupervised Additive Models

This article presents a semisupervised modeling framework that combines feature-based (x) data and graph-based (G) data for classification/regression of the response Y. In this semisupervised setting, Y is observed for a subset of the observations (labeled) and missing for the remainder (unlabeled). The Propagated Scoring algorithm proposed for fitting this model is a semisupervised fixed-point regularization approach that essentially extends the generalized additive model into the semisupervised setting. I first articulate when semisupervised degeneracies are expected within my framework, and then provide a general regularization strategy to address such circumstances. For statistical analysis, I establish that the approach uses shrinking smoothers, provide circumstances in which when the result is consistent, provide measures of inference and description, and establish clear connections to supervised models. Several semisupervised approaches have been considered for the classification problem posed, typ...
Masquerading Bundle-Branch Block—Electrophysiological Correlation

The term masquerading bundle-branch block has been used to describe a peculiar electrocardiographic abnormality in which the standard leads exhibit a left bundle-branch block pattern while the precordial leads manifest a right bundle-branch configuration. Autopsy studies of patients who have had this electrocardiographic pattern in life have shown diffuse conduction system disease, but direct recordings of conduction system function have never been reported. We recently cared for a man with masquerading bundle-branch block, and in this report we summarize the results of invasive electrophysiological testing. Our findings confirm that masquerading bundle-branch block can be associated with severe and diffuse conduction system disease, and that patients with this finding may require permanent pacemaker implantation, especially if they are symptomatic.
STRESS RESPONSES IN AVIAN EMBRYOS

The day 13–14 chicken embryo is a useful model for studies on prenatal stress responses. Free dopamine, norepinephrine and epinephrine in its plasma, amniotic and allantoic fluid respond to a variety of stresses. The allantoic fluid also contains conjugated catecholamines and conjugated steroids. However, a blood/allantois barrier excludes free thyroid hormones and free steroids, and insulin. On the other hand, the allantoic fluid contains at least 40 amino acids (including six excitatory amino acids) and related compounds. Most, possibly all, components of the allantoic fluid are regulated at specific blood/allantois and amnion/allantois barriers, and they respond to ethanol stress and metabolite loading differentially. The avian allantois is a depot for important metabolites and messenger substances which seems to be controlled by as yet unidentified hormones
Finite equational bases for finite algebras in a congruence-distributive equational class*

Abstract Does every finite algebraic system A with finitely many operations possess a finite list of polynomial identities (laws), valid in A , from which all other such identities follow? Surprisingly, no ( R. C. Lyndon, 1954 ). The answer is, however, affirmative for various particular kinds of algebraic systems, such as finite groups (Oates and Powell), finite lattices, and even finite lattice-ordered algebraic systems (McKenzie). The purpose of the present paper is to provide a sufficient condition that guarantees an affirmative answer without referring to any particular kind of operation: It is sufficient for A to be a finite member of an equational class of algebraic systems whose congruence lattices are distributive. The proof is constructive. Applications include the case of lattice-ordered algebraic systems.
Ion-mixing mode and model for density rise in confined plasmas

A model for the rate of density rise observed when neutral gas is fed into the plasma chamber is presented for regimes where known collisional transport processes do not provide an adequate explanation. A dense layer of cold plasma produced at the edge of the plasma column and the resulting ion-temperature gradient, sharper than the relative density gradient, can lead to the excitation of electron temperature fluctuations driven by ion drift modes. These can induce a new inflow of electrons and ions under realistic conditions.
Treatment Implications of High-Resolution Manometry Findings: Options for Patients With Esophageal Dysmotility

High-resolution manometry (HRM) has significantly impacted diagnosis and management of achalasia in particular, and has improved characterization of other motor disorders. Achalasia, the most profound esophageal motor disorder, is characterized by esophageal outflow obstruction from abnormal relaxation of the lower esophageal sphincter (LES) during swallowing, and presents with transit symptoms (dysphagia, regurgitation). Esophageal body motor disorders include both inhibitory nerve dysfunction associated with hypermotility or spasm, and hypomotility disorders with poor contraction. The implications of hypermotility disorders are both perceptive and obstructive. On the other hand, hypomotility disorders have reflux implications because of abnormal barrier function at the LES, and abnormal bolus clearance. Esophageal outflow obstruction in achalasia responds favorably to disruption of the LES, and outcome may be predicted by HRM subtyping of achalasia. Identification of dominant (perceptive vs. obstructive) mechanisms of symptom generation help direct therapy of hypermotility disorders, while hypomotility disorders typically require management of concurrent reflux disease.
Rhinovirus Replication in Human Macrophages Induces NF-κB-Dependent Tumor Necrosis Factor Alpha Production

Rhinoviruses (RV) are the major cause of acute exacerbations of asthma and chronic obstructive pulmonary disease (COPD). Rhinoviruses have been shown to activate macrophages, but rhinovirus replication in macrophages has not been reported. Tumor necrosis factor alpha (TNF-alpha) is implicated in the pathogenesis of acute exacerbations, but its cellular source and mechanisms of induction by virus infection are unclear. We hypothesized that rhinovirus replication in human macrophages causes activation and nuclear translocation of NF-kappaB, leading to TNF-alpha production. Using macrophages derived from the human monocytic cell line THP-1 and from primary human monocytes, we demonstrated that rhinovirus replication was productive in THP-1 macrophages, leading to release of infectious virus into supernatants, but was limited in monocyte-derived macrophages, likely due to type I interferon production, which was robust in monocyte-derived but deficient in THP-1-derived macrophages. Similar to bronchial epithelial cells, only small numbers of cells supported complete virus replication. We demonstrated RV-induced activation of NF-kappaB and colocalization of p65/NF-kappaB nuclear translocation with virus replication in both macrophage types. The infection induced TNF-alpha release in a time- and dose-dependent, RV serotype- and receptor-independent manner and was largely (THP-1 derived) or completely (monocyte derived) dependent upon virus replication. Finally, we established the requirement for NF-kappaB but not p38 mitogen-activated protein kinase in induction of TNF-alpha. These data suggest RV infection of macrophages may be an important source of proinflammatory cytokines implicated in the pathogenesis of exacerbations of asthma and COPD. They also confirm inhibition of NF-kappaB as a promising target for development of new therapeutic intervention strategies.
Critic-driven ensemble classification

We develop new rules for combining the estimates obtained from each classifier in an ensemble, in order to address problems involving multiple (>2) classes. A variety of techniques have been previously suggested, including averaging probability estimates from each classifier, as well as hard (0-1) voting schemes. In this work, we introduce the notion of a critic associated with each classifier, whose objective is to predict the classifier's errors. Since the critic only tackles a two class problem, its predictions are generally more reliable than those of the classifier and, thus, can be used as the basis for improved combination rules. Several such rules are suggested here. While previous techniques are only effective when the individual classifier error rate is p<0.5, the new approach is successful, as proved under an independence assumption, even when this condition is violated-in particular, so long as p+q<1, with q the critic's error rate. More generally, critic-driven combining is found to achieve significant performance gains over alternative methods on a number of benchmark data sets. We also propose a new analytical tool for modeling ensemble performance, based on dependence between experts. This approach is substantially more accurate than the analysis based on independence that is often used to justify ensemble methods.
Biomicroscopy and Argon Laser Photocystotomy of Free-Floating Vitreous Cysts

Laser photocystotomy is a new technique that employs a 200 mu beam of argon laser at a setting of 0.1 second and 500 mW to accomplish cystotomy of symptomatic free-floating vitreous cysts. It was successful in treating this type of cyst in the right eye of a 23-year-old man. The paper also includes the first photographic documentation of the biomicroscopic features of a free-floating vitreous cyst.
Invasion by Toxoplasma gondii Establishes a Moving Junction That Selectively Excludes Host Cell Plasma Membrane Proteins on the Basis of Their Membrane Anchoring

The protozoan parasite Toxoplasma gondii actively penetrates its host cell by squeezing through a moving junction that forms between the host cell plasma membrane and the parasite. During invasion, this junction selectively controls internalization of host cell plasma membrane components into the parasite-containing vacuole. Membrane lipids flowed past the junction, as shown by the presence of the glycosphingolipid GM1 and the cationic lipid label 1.1′-dihexadecyl-3-3′-3-3′-tetramethylindocarbocyanine (DiIC16). Glycosylphosphatidylinositol (GPI)-anchored surface proteins, such as Sca-1 and CD55, were also readily incorporated into the parasitophorous vacuole (PV). In contrast, host cell transmembrane proteins, including CD44, Na+/K+ ATPase, and β1-integrin, were excluded from the vacuole. To eliminate potential differences in sorting due to the extracellular domains, parasite invasion was examined in host cells transfected with recombinant forms of intercellular adhesion molecule 1 (ICAM-1, CD54) that differed in their mechanism of membrane anchoring. Wild-type ICAM-1, which contains a transmembrane domain, was excluded from the PV, whereas both GPI-anchored ICAM-1 and a mutant of ICAM-1 missing the cytoplasmic tail (ICAM-1–Cyt−) were readily incorporated into the PV membrane. Our results demonstrate that during host cell invasion, Toxoplasma selectively excludes host cell transmembrane proteins at the moving junction by a mechanism that depends on their anchoring in the membrane, thereby creating a nonfusigenic compartment.
Induction chemoradiation therapy prior to esophagectomy is associated with superior long-term survival for esophageal cancer.

Summary The purpose of this study was to examine the role of induction chemoradiation in the treatment of potentially resectable locally advanced (T2-3N0 and T1-3N+) esophageal cancer utilizing a large national database. The National Cancer Data Base (NCDB) was queried for all patients undergoing esophagectomy for clinical T2-3N0 and T1-3N+ esophageal cancer of the mid- or lower esophagus. Patients were stratified by the use of induction chemoradiation therapy versus surgery-first. Trends were assessed with the Cochran–Armitage test. Predictors of receiving induction therapy were evaluated with multivariable logistic regression. A propensity-matched analysis was conducted to compare outcomes between groups, and the Kaplan–Meier method was used to estimate long-term survival. Within the NCDB, 7921 patients were identified, of which 6103 (77.0%) were treated with chemoradiation prior to esophagectomy, while the remaining 1818 (23.0%) were managed with surgery-first. Use of induction therapy increased over time, with an absolute increase of 11.8% from 2003–2011 (P < 0.001). As revealed by the propensity model, induction therapy was associated with higher rates of negative margins and shorter hospital length of stay, but no differences in unplanned readmission and 30-day mortality rates. In unadjusted survival analysis, induction therapy was associated with better long-term survival compared to a strategy of surgery-first, with 5-year survival rates of 37.2% versus 28.6%, P < 0.001. Following propensity score matching analysis, the use of induction therapy maintained a significant survival advantage over surgery-first (5-year survival: 37.9% vs. 28.7%, P < 0.001). Treatment with induction chemoradiation therapy prior to surgical resection is associated with significant improvement in long-term survival, even after adjusting for confounders with a propensity model. Induction therapy should be considered in all medically appropriate patients with resectable cT2-3N0 and cT1-3N+ esophageal cancer, prior to esophagectomy.
Nephrogenic Adenoma of the Urinary Tract A Review

Nephrogenic adenoma (NA) is an uncommon and intriguing lesion in the urinary tract. The pathogenesis of NA is not entirely clear. NA was considered to be a metaplastic process of the urothelium in response to chronic irritation of the urinary tract. However, recent evidence has shown that NA is not a metaplastic lesion but rather a proliferation of exfoliated and implanted renal epithelial cells in the urinary tract. Histologically, NAs exhibit, singly or in combination, tubules, small papillae, and microcystic structures lined by cells with little cytological atypia and focal hobnail changes. Solid formations and compressed spindled cells within a fibromyxoid background are rarely observed. Differential diagnosis includes, but is not limited to, malignant neoplasms occurring at the same sites, in particular urothelial carcinoma with deceptively bland morphology (with small tubules, microcystic and nested variants), prostatic adenocarcinoma, and clear cell adenocarcinoma. Immunohistochemical studies with antibodies targeting members of the paired box gene family (PAX2 and/or PAX8) in NAs may be helpful in the differential diagnosis of urothelial lesions and prostatic adenocarcinoma. NAs are most likely to be confused with clear cell adenocarcinoma, especially in small biopsy specimens. This is confounded by both lesions being frequently positive for PAX2, PAX8, and CK7 and not infrequently positive for p504S (α-methylacyl-CoA-racemase, AMACR) by immunohistochemistry. Recognition of its characteristic morphological patterns and awareness of its unusual architectural and cytological features are important in making the diagnosis of NA and distinguishing this lesion from its mimickers.
Give it a “TWIST!”: Turning writing into student thinking

A number of studies have shown that the active process of writing can promote deeper and more meaningful student learning. Writing can also serve as a motivator to learn, and lead to longer term retention of the material under study. However, for the instructor, adopting a writing approach in the classroom often means additional time spent grading. This paper offers a “twist” on more traditional classroom writing strategies. The “twist” comes in the form of free-writing activities. This paper will describe what free-writing activities are and how they can be effectively and efficiently used in the classroom - even in a large classroom. The free-writing activities to be described are used with introductory level physics students at American University. These short activities are designed to help students confront and elicit their conceptions regarding a given topic or concept in physics. Misconceptions in student thinking can be teased out using free-writing activities, before they can turn into a more serious problem and significantly hinder student learning. Strategies for implementing free-writing activities in the physics classroom will be described. In addition, samples of student writing will be shared. Finally, techniques for quickly and efficiently providing students with effective feedback will be shared. The usefulness of these techniques in terms of enhancement of student understanding will also be discussed.
Differences in the hemodynamic response to event-related motor and visual paradigms as measured by near-infrared spectroscopy

Several current brain imaging techniques rest on the assumption of a tight coupling between neural activity and hemodynamic response. The nature of this neurovascular coupling, however, is not completely understood. There is some evidence for a decoupling of these processes at the onset of neural activity, which manifests itself as a momentary increase in the relative concentration of deoxyhemoglobin (HbR). The existence of this early component of the hemodynamic response function, however, is controversial, as it is inconsistently found. Near infrared spectroscopy (NIRS) allows quantification of levels of oxyhemoglobin (HbO(2)) and HbR during task performance in humans. We acquired NIRS data during performance of simple motor and visual tasks, using rapid-presentation event-related paradigms. Our results demonstrate that rapid, event-related NIRS can provide robust estimates of the hemodynamic response without artifacts due to low-frequency signal components, unlike data from blocked designs. In both the motor and visual data the onset of the increase in HbO(2) occurs before HbR decreases, and there is a poststimulus undershoot. Our results also show that total blood volume (HbT) drops before HbO(2) and undershoots baseline, raising a new issue for neurovascular models. We did not find early deoxygenation in the motor data using physiologically plausible values for the differential pathlength factor, but did find one in the visual data. We suggest that this difference, which is consistent with functional magnetic resonance imaging (fMRI) data, may be attributable to different capillary transit times in these cortices.
Postoperative Bile Duct Injuries

Injuries of the bile ducts commonly occur iatrogenically, as a complication of surgical procedures. Such injuries contribute to significant morbidity and even death in affected patients. Management of postoperative bile duct injuries continues to evolve, but traditional surgical management strategies have been increasingly replaced by minimally invasive therapies in the past decade. Endoscopic therapies figure prominently in this field, and the role of this approach is increasingly supported by data from larger prospective series. This section will review bile duct injuries, particularly those after laparoscopic cholecystectomy and liver transplantation. Management of these injuries, with emphasis on endoscopic therapies and outcomes, will be presented.
Optimum design of electron beam-semiconductor linear low-pass amplifiers&#8212;Part I: Bandwidth and rise time

This paper begins with a brief description of the basic electrical characteristics and principles of operation of the lumped-element electron-beam-excited-semiconductor amplifier. It is shown that stable current gains of several thousand may be obtained through the interaction of a 10-keV electron beam with a shallow reverse-biased p-n junction device (semiconductor target). Simplest case analyses of the transient-response rise time and RF gain and bandwidth are presented for an idealized nondistributed target structure, using the assumptions of shallow beam penetration across the drift region, carrier transport with a constant velocity, and a resistive load impedance. The dynamic response is shown to be determined jointly by the carrier transit time and the target capacitance in such a way that it is possible to optimize the target rise time or bandwidth by appropriate choices of drift-region width. The optimum drift-region width and the ultimate rise times and bandwidths are evaluated in terms of the target area, load impedance, carrier drift velocity, and semiconductor dielectric constant. It is shown that lumped-element semiconductor targets can readily be designed for subnanosecond rise times and broad bandwidths without compromise of the high current gain possible in these devices.
High temperatures and cause-specific mortality

High ambient temperatures are hazardous, with a significant body of research documenting increases in morbidity and mortality during hot weather.1 And yet, every heat-related death is preventable. Improving understanding of who is most vulnerable, where they are located and early warning systems that effectively communicate the risks of hot temperatures could decrease the current health burden and increase resilience to a warmer world. Surprisingly, understanding is limited of the characteristics that increase vulnerability.1 Gasparrini et al (this issue) provide a comprehensive analysis of specific causes of death that were increased during hot weather in regions of England and Wales. Overall mortality increased 2.1% per degree Celsius above a heat threshold identified for each region. For stroke, ischaemic heart disease, chronic ischaemic heart diseases and respiratory infections, the attributable burden increased >10%. The attributable burden is lower for other causes, but the absolute numbers of deaths is large (eg, there were >1000 deaths each over the study period for myocardial infarction, chronic obstructive pulmonary disease, …
‘Distress at the bedside in the PICU: Nurses’ and respiratory therapists’ experiences in caring for children with complex medical or neurologic conditions’

AbstractIntroductionIntensive care unit (ICU) care provided to children with complex chronic medical and neurological conditions is a frequent source of conflict and distress.ObjectiveTo quantify the extent to which pediatric ICU (PICU) nurses (RNs) and respiratory therapists (RTs) experience distress when caring for children with complex medical and developmental disabilities, and to explore which provider characteristics lessen or increase this distress.MethodsRNs and RTs at three pediatric hospitals completed an online scenario-based survey to assess their feelings toward a hypothetical patient with complex, chronic medical conditions, and neurological impairment. Twenty-four statements were created to capture features of moral distress, mismatch of expectations, and job dissatisfaction, and providers indicated degree of agreement with each statement. Responses were tabulated to create a Total Distress Score (TD) which was further subdivided into Moral Distress (MD), Mismatch of Expectations (ME), and ...
STUDIES ON THE TWORT-D'HERELLE PHENOMENON.

1. The experiments here reported were carried out with a lytic principle isolated from the feces of normal rabbits. 2. It seems that bacteriophage is constantly present in the feces of caged laboratory rabbits. 3. A lytic filtrate active for Strain Shiga 73 (in a dilution of 1:1,000,000) and for the typhoid bacillus (in a dilution of 1:1,000), after twenty successive passages with Shiga bacillus was active, for its homologous strain, in a dilution of about 1:10,000,000,000 but no longer possessed any lytic activity for the typhoid strain. The same filtrate, after twenty successive passages with typhoid bacillus, was similarly active in a dilution of 1:10,000,000,000 for the typhoid strain but was only feebly active for the Shiga strain. 4. The passage of the lytic principle through collodion membranes was never observed. 5. No appreciable diminution in the activity of the filtrates was observed after exposure to cholesterol or lecithin. Killed bacterial suspensions, however, were found to exert a considerable neutralizing effect on the active principle. 6. Formol titrations of lysed cultures lead to the conclusion that the bacteriolysis caused by the bacteriophage is not a true proteolysis but rather a simple plasmolysis of the bacterial cell and not a splitting effect of the protein molecule. 7. We have never obtained active filtrates with the leucocytes of immune animals by the method of Lisbonne, Boulet, and Carrere (14). 8. It would appear, from the experiments, that the immunization of rabbits with the lytic principle results in the disappearance of the bacteriophage from their intestines. 9. All the sera from rabbits immunized with antityphoid or antiShiga filtrates agglutinated respectively the typhoid or Shiga bacilli. 10. Similarly, these sera fixed complement strongly in the presence of the homologous antigen. Five or six times the amount of serum was required to fix complement in the presence of heterologous antigen. 11. All of the immune sera were found to be more or less antilytic. In no case was a strictly specific antilysin obtained.
Superconducting and magnetic properties of ZrV2−xFex and HfV2−xFex Alloys

The superconducting, magnetic and structural properties of the ternary alloys ZrV2−xFex and HfV2−xFex (x = 0 to 2) have been investigated. The superconducting transition temperature Tc and the upper critical field Hc2 are determined from resistivity measurements. The Curie temperatures TM of the Fe-rich compositions are determined. The crystal structures of the terminal phases (x = 0 and x = 2) are of the cubic Laves type (C15) while many of the intermediate compositions have the hexagonal Laves structure (C14 type). The lattice parameters of the various compositions are reported. For dilute Fe impurities in HfV2 and ZrV2, Hc2 is enhanced over that of the parent compounds. These results are interpreted as arising from a negative exchange coupling between the Fe and the conduction electron spins. Es wurden die supraleitenden, magnetischen und strukturellen Eigenschaften der ternaren Legierungen ZrV2−xFex und HfV2−xFex(x = 0 bis 2) untersucht. Die Supraleitungsubergangstemperatur Tc und das obere kritische Feld Hc2 werden aus Widerstandsmessungen bestimmt. Die Curie-Temperaturen TM der Fe-reichen Verbindungen werden bestimmt. Die Kristallstrukturen der Endphasen (x = 0 und x = 2) sind vom kubischen Lavestyp (C15) wahrend eine Reihe der Zwischenverbindungen die hexagonale Lavesstruktur (C14) besitzt. Die Gitterparameter der verschiedenen Zusammensetzungen werden mitgeteilt. Fur verdunnte Eisenstorstellen in HfV2 und ZrV2, wird Hc2 uber den Wert der Stammverbindungen angehoben. Diese Ergebnisse werden mit der Annahme interpretiert, das sie von einer negativen Austauschkopplung zwischen den Fe- und den Leitungselektronenspins herruhren.
Computer utilization in teaching concepts: is it reality or illusion?

It is pointed out that engineering educators have felt the value of using computational tools to complement their analytical procedure and help enhance interest in their subjects and boost students' understanding of involved concepts. This is particularly true for electromagnetics education, which has traditionally relied on abstract concepts and mathematical operations that involve vector quantities varying with time and space. From the educational side, the roles of analytical and computational techniques are complementary from several viewpoints. First, understanding of the mathematical concepts and operations may be greatly enhanced through the use of computational tools and systems. Second, computer-generated movies of complex scattering and radiation problems provide a valuable tool that helps students understand the physical phenomena underlying complex interactions of electromagnetic waves with materials and structures. Finally, the use of computational tools and design software to model and simulate microwave components and systems provides a valuable insight into realistic microwave design problems. >
Lipopolysaccharide Causes an Increase in Intestinal Tight Junction Permeability in Vitro and in Vivo by Inducing Enterocyte Membrane Expression and Localization of TLR-4 and CD14

Bacterial-derived lipopolysaccharides (LPS) play an essential role in the inflammatory process of inflammatory bowel disease. A defective intestinal tight junction (TJ) barrier is an important pathogenic factor of inflammatory bowel disease and other inflammatory conditions of the gut. Despite its importance in mediating intestinal inflammation, the physiological effects of LPS on the intestinal epithelial barrier remain unclear. The major aims of this study were to determine the effects of physiologically relevant concentrations of LPS (0 to 1 ng/mL) on intestinal barrier function using an in vitro (filter-grown Caco-2 monolayers) and an in vivo (mouse intestinal perfusion) intestinal epithelial model system. LPS, at physiologically relevant concentrations (0 to 1 ng/mL), in the basolateral compartment produced a time-dependent increase in Caco-2 TJ permeability without inducing cell death. Intraperitoneal injection of LPS (0.1 mg/kg), leading to clinically relevant plasma concentrations, also caused a time-dependent increase in intestinal permeability in vivo . The LPS-induced increase in intestinal TJ permeability was mediated by an increase in enterocyte membrane TLR-4 expression and a TLR-4–dependent increase in membrane colocalization of membrane-associated protein CD14. In conclusion, these studies show for the first time that LPS causes an increase in intestinal permeability via an intracellular mechanism involving TLR-4–dependent up-regulation of CD14 membrane expression.
Macromineral disorders of the transition cow

Four macrominerals have the distinction of being involved in the "downer cow" syndrome, which is, unfortunately, often associated with parturition in cows. Inadequate blood calcium (Ca), phosphorus (P), magnesium (Mg), or potassium (K) concentrations can cause a cow to lose the ability to rise to her feet because these minerals are necessary for nerve and muscle function. Less severe disturbances in blood concentrations of these minerals can cause reduced feed intake, poor rumen and intestine motility, poor productivity, and increased susceptibility to other metabolic and infectious disease. Mechanisms for maintaining blood Ca, P, Mg, and K concentrations perform efficiently most of the time, but occasionally these homeostatic mechanisms fail and metabolic diseases such as milk fever occur. Understanding how and why these mechanisms fail may allow the practitioner to develop strategies to avoid these disorders.
Geomagnetic parameters derived from an analytic description of the Earth's magnetic field.

A recent geomagnetic model containing 720 trend and trigonometric coefficients represents each spherical harmonic coefficient as a continuous function of time which exactly duplicates the IGRF coefficients at the nine IGRF epochs (1945 to 1985 at five year intervals) and allows a reasonable prediction five years beyond the last epoch. Use of this model permits time derivatives of magnetic elements and other derived quantities to be taken so that a detailed look at several geomagnetic parameters vs time can be obtained. It is shown that from 1945 to 1985 the quadrupole field contributed 2.6 times more power to the secular variation field on the surface of the Earth than the dipole field. It is also shown that the root-mean-squared surface field shows a strong periodicity which may be related to the solar cycle. This apparent solar-cycle effect diminishes with time as more satellite data are used indicating that an appreciable part of it may be caused by noisy data and a poor distribution of data for a couple of decades following World War II.
Training wheels in a user interface

New users of high-function application systems can become frustrated and confused by the errors they make in the early stages of learning. A training interface for a commercial word processor was designed to make typical and troublesome error states “unreachable,” thus eliminating the sources of some new-user learning problems. Creating a training environment from the basic function of the system itself afforded substantially faster learning coupled with better learning achievement and better performance on a comprehension post-test. A control group spent almost a quarter of their time recovering from the error states that the training interface blocked off. We speculate on how this training strategy might be refined, and more generally, on how function should be organized in a user interface.
Oxalic Acid as a Fungal Acaracidal Virulence Factor

Cell-free culture supernatants of the entomopathogenic fungus Beauveria bassiana (Bals.) Vuillemin were able to induce mortality in several tick species, including adult Ambylomma americanum (L.), Ambylomma maculatum Koch, and Ixodes scapularis Say. Four lines of experimental evidence support the hypothesis that oxalic acid secretion by B. bassiana, coupled to a reduction in the pH of the medium, act as potent acaricidal factors during pathogenesis. 1) Acaracidal activity of culture supernatants was retained after treatments including boiling and protease digestion, but was lost after dialysis. 2) Metabolite analyses indicated oxalate to be the major secreted organic compound present in the active culture supernatants. 3) Treatment of ticks with the pure compound oxalate at pH 4.0 resulted in almost 80% mortality in adult A. americanum ticks within 14 d, whereas treatment of ticks with oxalate at pH 7.0, or with formate, citrate, or phosphate at both pH 4 and 7 resulted in <10% mortality, even after 28 d. 4) Cell-free culture supernatants from B. bassiana mutants with decreased oxalate production displayed lower acaricide activity than wild type.
Algorithms for scalable and network-adaptive video coding and transmission

Real-time multimedia services over the Internet face some fundamental challenges due to time constraints of those applications and network variations in bandwidth, delay and packet loss rate. Our research addresses the problem of network-adaptive video coding and streaming based on source codecs that provide scalability to match the network environments. The first part of the thesis focuses on scheduling algorithm design for network-adaptive video streaming. We extend previous work on rate-distortion optimized video streaming to address more general coding techniques that support multiple decoding paths to enhance adaptation flexibility. Prior work had only considered a single decoding path. Examples of multiple decoding paths include cases where there are multiple redundant representations of the media data or where error concealment is used. An example of these codes is our proposed multiple description layered coding (MDLC), which combines the advantages of layered coding and multiple description coding. This work is composed of several main components: (1) a new source model called directed acyclic hyperGraph (DAHG) to estimate the expected end-to-end distortion; (2) rate-distortion based scheduling algorithms to adjust dynamically the system's real-time redundancy to match the channel behavior; and (3) performance analysis on both source redundancy and transport redundancy. Experimental results show that the proposed streaming framework can provide a very robust and efficient video communication for real-time applications over lossy packet networks. The second part proposes a framework for adaptive scalable video coding using Wyner-Ziv techniques. The current scalable video coding standards suffer to some degree from a combination of lower coding performance and higher coding complexity, as compared to non-scalable coding. A key issue is how to exploit temporal correlation efficiently in scalable coding. We propose a novel scalable coding approach by introducing distributed source coding in enhancement layer prediction in order to achieve a better coding performance with reasonable encoding complexity. Experimental results show significant improvements in coding efficiency over MPEG-4 FGS, especially for video sequences with high temporal correlation.
Roles of aldosterone and angiotensin in maturation of sodium appetite in furosemide-treated rats

When rats are treated with furosemide, there is a rapid natriuresis. However, increased sodium appetite does not occur until some time later. One hypothesis to explain this delay is that increased circulating levels of the hormones of sodium depletion prime or sensitize the brain circuits involved in sodium appetite, perhaps by induction of target gene(s). In the present study, we describe the time course of the temporal maturation of sodium appetite after furosemide treatment and the associated changes in plasma levels of ANG II and aldosterone and in plasma volume. Sodium appetite is modest 3 h after furosemide treatment, is increased after 12 h, and is still larger after 24 h. This pattern is evident with repeated testing. Plasma levels of aldosterone and plasma renin activity are substantially increased 3 h after furosemide treatment, and so the NaCl appetite cannot result simply from progressively increasing levels of these hormones. Furthermore, activation of the subfornical organ and the ventral lamina terminalis, assessed with c-Fos immunocytochemistry, did not differ across these three times. Metyrapone, an inhibitor of adrenal steroid synthesis, was used to examine sodium appetite in the absence of elevations in aldosterone after furosemide treatment. Although metyrapone effectively blocked the increase in aldosterone, it was without effect on the appetite 3 or 24 h after furosemide treatment. Furthermore, elevations of plasma aldosterone by the use of minipumps for several days before furosemide treatment did not prime or potentiate but instead tended to inhibit the induced sodium appetite, despite achieving levels of aldosterone and plasma renin activity typically associated with a robust sodium appetite. Infusions of DOCA gave a similar result. Lastly, minipump infusions of ANG II also did not potentiate sodium appetite. Thus neither addition nor subtraction of these hormones alone influenced sodium appetite under these conditions.
The Black Rule is Best

We assess the frequencies with which fourteen voting rules encounter nine voting paradoxes and ties, using a statistical model that simulates ranking profiles that follow the same distribution as ranking profiles in actual elections. Thus the frequencies that we estimate from our simulated data are likely to be very close to the frequencies that we can expect to observe in actual elections. We find that two Condorcet consistent voting rules, the Black rule and the Nanson rule, perform better than the other rules, especially in elections with few voters. The Bucklin rule, the plurality rule, and the anti-plurality rule tend to perform worse than the other eleven rules, especially when the number of voters gets large.
Cotton Rats and Other Small Mammals as Hosts for Immature Dermacentor variabilis (Acari: Ixodidae) in Central Oklahoma

Eight species of small mammals were evaluated as potential hosts for American dog ticks, Dermacentor variabilis (Say), in an upland, tallgrass prairie study site in central Oklahoma. Only hispid cotton rats, Sigmodon hispidus, and deer mice, Peromyscus maniculatus, were found to be important hosts for immature D. variabilis. Although D. variabilis larvae and nymphs frequently infested both cotton rats and deer mice, cotton rats were the most important host species for both immature stages in the study area. Cotton rats constituted 63.2% of the total 530 small mammals captured and were hosts to 85.2% of all larvae and 88.7% of all nymphs. Deer mice accounted for 19.8% of all small mammals captured and were hosts for 14.5% of the larvae and 10.8% of the nymphs recovered. The remaining small mammal species were hosts for <1% of the immature ticks collected. Larval infestations peaked during summer, whereas summer and spring peaks were noted for the nymphal infestations. The relative importance of cotton rats and deer mice as hosts for immature ticks could be largely, but not completely, explained by cotton rats being more than three times as abundant as deer mice. Attachment site data indicated that differences in grooming behavior also might be partially responsible for the larger infestations observed on cotton rats. Other possible ecological and behavioral explanations of the heavy infestations observed on cotton rats are discussed.
Spatial Mapping of Efficiency of GaN/InGaN Nanowire Array Solar Cells Using Scanning Photocurrent Microscopy

GaN–InGaN core–shell nanowire array devices are characterized by spectrally resolved scanning photocurrent microscopy (SPCM). The spatially resolved external quantum efficiency is correlated with structure and composition inferred from atomic force microscope (AFM) topography, scanning transmission electron microscope (STEM) imaging, Raman microspectroscopy, and scanning photocurrent microscopy (SPCM) maps of the effective absorption edge. The experimental analyses are coupled with finite difference time domain simulations to provide mechanistic understanding of spatial variations in carrier generation and collection, which is essential to the development of heterogeneous novel architecture solar cell devices.