cssi/SciSciGPT-SciSciNet huggingface dataset:
Metallothionein-III Antagonizes the Neurotoxic and Neurotrophic Effects of Amyloid β Peptides

Metallothionein-III (MT-III) protects cerebral cortical neurons in established culture from the toxic effect of amyloid β peptides (Aβs). Protection is concentration dependent and approaches 100% at 0.1 μM. The EC50 value estimated at 5 μM Aβ1–40 is 2 nM. At higher concentrations (>0.1 μM), MT-III also antagonizes the trophic effect of Aβ1–40 on cerebral cortical neurons in early cultures. Because only the fibrillar, SDS-resistant form of Aβ aggregates are thought to be neurotoxic, we analyzed and compared Aβ1–40 aggregates formed in the presence and absence of MT-III using SDS–PAGE. Results show that aggregates formed in the absence of MT-III are predominantly SDS-resistant whereas those formed in its presence are mostly SDS-soluble. Neither MT-I nor -II exhibits any of the effects of MT-III. On the basis of these results, we propose that MT-III alleviates Aβs' neurotoxic effect by abolishing the formation of toxic aggregates of Aβs and that it may play a specific and important role in protecting the brain from the deleterious effects of Aβs.
Electron tomography of the contact between T cells and SIV/HIV-1: implications for viral entry.

The envelope glycoproteins of primate lentiviruses, including human and simian immunodeficiency viruses (HIV and SIV), are heterodimers of a transmembrane glycoprotein (usually gp41), and a surface glycoprotein (gp120), which binds CD4 on target cells to initiate viral entry. We have used electron tomography to determine the three-dimensional architectures of purified SIV virions in isolation and in contact with CD4+ target cells. The trimeric viral envelope glycoprotein surface spikes are heterogeneous in appearance and typically ∼120 A long and ∼120 A wide at the distal end. Docking of SIV or HIV-1 on the T cell surface occurs via a neck-shaped contact region that is ∼400 A wide and consistently consists of a closely spaced cluster of five to seven rod-shaped features, each ∼100 A long and ∼100 A wide. This distinctive structure is not observed when viruses are incubated with T lymphocytes in the presence of anti-CD4 antibodies, the CCR5 antagonist TAK779, or the peptide entry inhibitor SIVmac251 C34. For virions bound to cells, few trimers were observed away from this cluster at the virion–cell interface, even in cases where virus preparations showing as many as 70 envelope glycoprotein trimers per virus particle were used. This contact zone, which we term the “entry claw”, provides a spatial context to understand the molecular mechanisms of viral entry. Determination of the molecular composition and structure of the entry claw may facilitate the identification of improved drugs for the inhibition of HIV-1 entry.
Augmented Hydrolysis of Diisopropyl Fluorophosphate in Engineered Mutants of Phosphotriesterase

The phosphotriesterase from Pseudomonas diminuta hydrolyzes a wide variety of organophosphate insecticides and acetylcholinesterase inhibitors. The rate of hydrolysis depends on the substrate and can range from 6000 s-1 for paraoxon to 0.03 s-1 for the slower substrates such as diethylphenylphosphate. Increases in the reactivity of phosphotriesterase toward the slower substrates were attempted by the placement of a potential proton donor group at the active site. Distances from active site residues in the wild type protein to a bound substrate analog were measured, and Trp131, Phe132, and Phe306 were found to be located within 5.0 A of the oxygen atom of the leaving group. Eleven mutants were created using site-directed mutagenesis and purified to homogeneity. Phe132 and Phe306 were replaced by tyrosine and/or histidine to generate all combinations of single and double mutants at these two sites. The single mutants W131K, F306K, and F306E were also constructed. Kinetic constants were measured for all of the mutants with the substrates paraoxon, diethylphenylphosphate, acephate, and diisopropylfluorophosphate. Vmax values for the mutant enzymes with the substrate paraoxon varied from near wild type values to a 4-order of magnitude decrease for the W131K mutant. There were significant increases in the Km for paraoxon for all mutants except F132H. Vmax values measured using diethylphenylphosphate decreased for all mutants except for F132H and F132Y, whereas Km values ranged from near wild type levels to increases of 25-fold. Vmax values for acephate hydrolysis ranged from near wild type values to a 10(3)-fold decrease for W131K. Km values for acephate ranged from near wild type to a 5-fold increase. Vmax values for the mutants tested with the substrate diisopropylfluorophosphate showed an increase in all cases except for the W131K, F306K, and F306E mutants. The Vmax value for the F132H/F306H mutant was increased to 3100 s-1. These studies demonstrated for the first time that it is possible to significantly enhance the ability of the native phosphotriesterase to hydrolyze phosphorus-fluorine bonds at rates that rival the hydrolysis of paraoxon.
T cell development and receptor diversity during aging.

The T cell system is a complex and highly dynamic system that is amazingly robust over many decades of human life. Its functional competence is determined not only by its size but also by its diversity. Homeostatic control mechanisms have to secure sufficient T cell replenishment while preventing loss of clonal diversity. Major homeostatic challenges include profound expansion and shrinkage of T cell clonotypes upon antigenic triggering and, more importantly, age-related changes in T cell regeneration. The ability of the thymus to rebuild a diverse repertoire ceases in the fifth decade of life. Emerging data suggest that the end of the 7th decade of life defines a critical time period when T cell homeostasis is no longer guaranteed and diversity of the naive T-cell repertoire collapses. Thus, failure of T cell homeostasis appears to result from cumulative defects of T cell generation. Elucidation of the underlying mechanisms will allow for extending this turning point to later in life; ultimately, interventions have to aim at restoring thymic function and complementary modes of T cell reconstitution.
Virtual Relationship Violence and Perspectives on Punishment: Do Gender or Nationality Matter?

Given the increasingly popular use of socially interactive technology (SIT), it is believed that the way in which individuals communicate and experience relationships has drastically been changing. For those who partake in this electronic world, damaging behaviors akin to those found in the real world have emerged. Yet, we know little about the extent of these behaviors in the context of romantic relationships, especially from a gender or cultural standpoint. Research on dating violence generally indicates that women experience in-person victimization at higher rates than men, although some research has called this into question. It also suggests that some national groups experience higher rates of violence than others. However, research is almost non-existent when it comes to exploring violence in the digital world. This study investigated gender and nationality in (1) the nature and extent of socially interactive intimate violence, and (2) perceptions of the seriousness of virtual relationship violence. Using a sample of students from the United States and Poland, findings revealed that socially interactive technology may serve as a new avenue for aggressing against partners, as virtual relationship violence was not uncommon and reflected some patterns present in the real world. Some unexpected patterns also emerged. The results of this research signal a possible transferability of covert intimate violence and highlight ways in which inequalities may exist in our virtual worlds.
Incidence and Risk Factors for Respiratory Complications in Patients Undergoing Esophagectomy for Malignancy: A NSQIP Analysis

Respiratory complications are the most frequent adverse events in patients undergoing esophagectomy for cancer, and their occurrence may negatively affect postoperative recovery and outcomes. We queried the American College of Surgeons National Surgical Quality Improvement Program dataset to study the rate and influence of pneumonia, unplanned intubation, and ventilator dependency >48 hours on the early outcomes after esophagectomy and risk factors for their development. We included adult patients with an esophageal or gastric cancer diagnosis who were treated with esophagectomy between 2005 and 2012 and grouped them into 2 categories with respect to development of respiratory complications. Early surgical outcomes (including 30-day mortality, overall morbidity, return to operating room, and length of hospital stay) were compared. Risk factors associated with respiratory complications after esophagectomy were assessed using modified Poisson regression. A total of 2945 patients were identified and respiratory complications were observed in 687 (23.3%) of them. We observed a significant decrease in respiratory complication rates after esophagectomy throughout the studied years. Patients who developed respiratory complications were older and had more comorbidities and longer operative time. These patients also had statistically significantly higher rates of 30-day mortality and overall morbidity and were more likely to return to the operating room and to stay in the hospital longer. On multivariable analysis, numerous factors, including advanced age, smoking, alcohol use, dyspnea, history of chronic obstructive pulmonary disease, and prolonged operative time, were found to be risk factors for developing respiratory complications. As the development of respiratory complications leads to worse early surgical outcomes after esophagectomy, efforts should be made to prevent their occurrence by identifying patients with significant risk factors.
An automated iterative algorithm for water and fat decomposition in three-point Dixon magnetic resonance imaging.

An iterative, outlier exclusion, second-order surface fitting algorithm has been developed to solve the well-known phase wraparound problem associated with in vivo applications of the three-point Dixon magnetic resonance imaging method. The technique was optimized for speed by reducing the problem to a pair of planar fits. The spatial misalignment between water and fat components due to the chemical shift was handled on a subpixel level by invoking the shift theorem of Fourier transformation. From the chemical shift corrected water and fat images, high quality recombined MRimages were generated. The algorithm was validated in both phantom and patient studies. In vivo breast images and pelvic images are provided as a demonstration of the method.
How fair can employers be

In this article we examine three concepts of fairness in employment decisions. Two of these concepts are widely known in the literature as “Fairness 1”and “Fairness 2”. The third concept, which we refer to as “Fairness 0”, is defined and introduced here. Fairness 0 applies to the hiring stage, whereas Fairness 1 and Fairness 2 apply to the placement or promotion stages of employment. Our results have important policy implications. We show that the three concepts of fairness can only rarely be achieved simultaneously.
Modeling and control of exhaust recompression HCCI using split injection

Homogeneous charge compression ignition (HCCI) is currently being pursued as a cleaner and more efficient alternative to conventional engine strategies. This paper presents an approach for modeling the effect of a small pilot injection during recompression on combustion in an HCCI engine with exhaust trapping, and a controller that uses the timing of this pilot injection to control the phasing of combustion. The model is incorporated into a nonlinear physical model presented in previous work that captures the effect of fuel quantity and intake and exhaust valve timings on work output and combustion phasing. It is seen that around the operating points considered, the effect of a pilot injection can be modeled as a change in the Arrhenius threshold, an analytical construct used to model the phasing of combustion as a function of the thermodynamic state of the reactant mixture. The relationship between injection timing and combustion phasing can be separated into a linear, analytical component and a nonlinear, empirical component. A feedback controller based on this model is seen to be effective in tracking a desired load-phasing trajectory and enables steady operation at low load conditions.
Biological Fitness of Culex quinquefasciatus (Diptera: Culicidae) Susceptible and Resistant to Bacillus sphaericus

Biological fitness of laboratory and field-collected strains of southern house mosquito, Culex quinquefasciatus Say, susceptible and resistant (37- and 31-fold upon selection) to the microbial agent, Bacillus sphaericus, were compared in the absence of B. sphaericus . The resistant strains showed significantly lower fecundity and fertility, but they had significantly higher survival rates than the susceptible strains. The preadult stages from females of resistant strains developed at slightly faster rates than those of the susceptible strains, which could result in a shorter generation time. However, lower fecundity was likely to lead to overall lower population growth rates than in the susceptible strains. Data provided evidence that the resistant strains exhibited fitness disadvantages in the absence of B. sphaericus. We suggest that once resistance to B. sphaericus is detected in the field, its use should be discontinued until the mosquito population becomes susceptible again because of the decline in number of resistant individuals. A strategy of resistance management by rotation of insecticides is discussed.
Further evidence on the ethics of managing earnings: an examination of the ethically related judgments of shareholders and non-shareholders

Abstract The current experimental study examines whether financial statement users' assessments of the ethicalness of earnings management is a function of intended benefit. Evening MBA students, assigned to the role of either a shareholder or non-shareholder, read three hypothetical scenarios involving a manager engaging in earnings management. In response to each scenario, participants judged the ethicalness of the earnings management incident and the likelihood that shareholders will suffer financially from the earnings management incident. The results of the study indicate that the ethicalness of earnings management was assessed less unethically for one of the three scenarios by shareholders when the earnings management was intended for company benefit. The results also show that intent did not influence ethicalness assessments among non-shareholders. These results provide some evidence to support Dye's (1988, pp. 201–207) analytic model and indicate that under certain conditions shareholders and non-shareholders are differentially influenced by the intent of earnings management.
Inhibition of JNK2 disrupts anaphase and produces aneuploidy in mammalian cells.

Abstract The JNK family members JNK1 and JNK2 regulate tumor growth and are essential for transformation by oncogenes such as constitutively activated Ras. The mechanisms downstream of JNK that regulate cell cycle progression and transformation are unclear. Here we show that inhibition of JNK2, but not JNK1, with either a dominant-negative mutant, a pharmacological inhibitor, or RNA interference caused an accumulation of mammalian cells with 4N DNA content. When observed by immunofluorescence, these cells progressed to metaphase without apparent defects in spindle formation or chromosome alignment to the metaphase plate, suggesting that the 4N accumulation is a result of postmetaphase defects. Consistent with this prediction, when JNK activity was suppressed, we observed defects in central spindle formation and chromosome segregation during anaphase. In contrast, cyclin-dependent kinase 1 activity, cyclin B1 protein, and Polo-like kinase 1 protein turnover remained intact when JNK was inhibited. In addition, continued inhibition of JNK activity did not block reentry into subsequent cell cycles but instead resulted in polyploidy. This evidence suggests that JNK2 functions in maintaining the genomic stability of mammalian cells by signaling that is independent of cyclin-dependent kinase 1/cyclin B1 down-regulation.
Important role of hydrogen bonds in the structurally polarized transition state for folding of the src SH3 domain

Experimental and theoretical studies on the folding of small proteins such as the chymotrypsin inhibitor 2 (CI-2) and the P22 Arc repressor suggest that the folding transition state is an expanded version of the native state with most interactions partially formed. Here we report that this picture does not hold generally: a hydrogen bond network involving two β-turns and an adjacent hydrophobic cluster appear to be formed in the folding transition state of the src SH3 domain, while the remainder of the polypeptide chain is largely unstructured. Comparison with data on other small proteins suggests that this structural polarization is a consequence of the topology of the SH3 domain fold. The non-uniform distribution of structure in the folding transition state provides a challenging test for computational models of the folding process.
Diverging length scales in diffusion-limited aggregation.

Applying finite-size scaling analysis to diffusion-limited aggregation (DLA) clusters grown in finite width strips on a square lattice we find that ${l}_{?}$ and ${l}_{\ensuremath{\perp}}$, the cluster lengths along and perpendicular, respectively, to the direction of growth, diverge as , respectively, where N is the number of particles in the cluster. We find numerically that ${\ensuremath{\nu}}_{?}$\ensuremath{\sim}(2/3) and ${\ensuremath{\nu}}_{\ensuremath{\perp}}$\ensuremath{\sim}(1/2). From the finite-size scaling analysis we derive the expression D=1+(1-${\ensuremath{\nu}}_{?}$)/${\ensuremath{\nu}}_{\ensuremath{\perp}}$ for the fractal dimension D of DLA clusters on a square lattice. The value D\ensuremath{\sim}(5/3) predicted from this relation agrees with the expected result.
Target-Symptom Psychopharmacology: Between the Forest and the Trees

Psychopharmacology practice seeks to fit specific treatments to specific disease processes. Although categorical diagnoses have improved focus on observable symptom constellations, these approximately 300 categories have limited benefits for illuminating underlying disease pathophysiology. Existing medications do not couple well to the symptom constellations of given disorders. Rather, current medications ameliorate symptoms overlapping among various disorders. Harnessing technology to identify a patient's wider symptom constellation, prioritizing and targeting symptoms across disorders, considering symptoms more dimensionally instead of "present or not," and eliciting factors necessary to improve adherence may allow medication selections to be tailored better to individual patients.
MDCT angiography of mesenteric bypass surgery for the treatment of chronic mesenteric ischemia

OBJECTIVE. Chronic mesenteric ischemia (CMI) is a serious condition that requires surgical or endovascular intervention. Surgical revascularization for the treatment of CMI uses different operative techniques including endarterectomy, vessel reimplantation, and mesenteric bypass. A basic understanding of the operative techniques is essential for the adequate interpretation of imaging studies in patients who have undergone surgery for CMI. In this article, we review the different operative techniques used in the treatment of CMI, discuss the results of surgical intervention for CMI, and illustrate how MDCT angiography (MDCTA) can be used for follow-up and for the detection of early and late complications after surgery.CONCLUSION. MDCTA is a powerful tool for the postoperative evaluation of patients with CMI. Early detection of graft dysfunction is critical to prevent graft occlusion and the development of potentially fatal mesenteric ischemia. MDCTA can detect early and late complications after surgery and...
Characterization of precipitates in MA/ODS ferritic alloys

Abstract Mechanically alloyed, oxide dispersion strengthened (MA/ODS) ferritic alloys are attractive for fusion reactor applications because of their potential for operation at high temperatures and also because the dispersed oxide particles may provide a trap for transmutant helium. The microstructural stability of MA/ODS Fe–14 wt% Cr–3% W–0.4% Ti–0.3% Y2O3 ferritic alloys was investigated by atom probe tomography. Atom probe tomography revealed that these MA/ODS 14YWT ferritic alloys contain a high number density of nanometer scale titanium-, yttrium- and oxygen-enriched nanoclusters in the as-extruded condition. These nanoclusters were found to be extremely resistant to coarsening at temperatures of at least 1000 °C.
Research Into Practice Through Professional Development

Bridging scientifically based theoretical approaches to quality instructional methods within classrooms in schools continues to be a challenge. Given the increasing demand for accountability, the implementation and evaluation of scientifically based interventions and strategies are necessary. This article describes the conceptual framework and the specific implementation activities that the state of Florida has used to ensure that quality, scientifically based instructional practices are implemented within classrooms and schools in Florida through a reconceptualized professional development model. The specific model and procedures that are described have been implemented and validated through the collaboration among professionals within the research community, the state department of education, and local staff developers, administrators, and teachers.
Comparative Pattern of Emergence of Heliothis zea and H. virescens (Lepidoptera: Noctuidae) from Overwintering Pupae

Mean Julian day for emergence from overwintering of tobacco budworms (TBW), Heliothis virescens (F.), was ca. 9 days earlier than that for bollworms (BW), H. zea (Boddie), in a plot of pigeon peas, Cajanus cajan L., in central Texas in 1980–1981. Females of both species emerged 4 or 5 days earlier than males. In areas where pigeon pea stalks were left in the field at the end of the growing season, a significant delay of 4 days occurred in the subsequent spring emergence of TBW when compared to areas where stalks were removed at the end of the growing season. This effect was less obvious with BW. Numbers of moths of either species that emerged from plots from which birds were excluded were not significantly different from those emerging from plots from which birds were not excluded; however, bird foraging activity in the plots during the overwintering period was low and the bird netting used was not effective in excluding birds. Synchrony between the spring emergence of male TBW and their capture in pheromone traps demonstrated the feasibility of using pheromone traps to monitor overwintering emergence. On the other hand, asynchrony between the capture and emergence of BW males indicated that movement of the species into the area may occur before emergence from overwintering.
Early examples of the biographical one‐person show genre: Emlyn Williams as Charles Dickens and Hal Holbrook's Mark Twain tonight!

(1985). Early examples of the biographical one‐person show genre: Emlyn Williams as Charles Dickens and Hal Holbrook's Mark Twain tonight!. Literature in Performance: Vol. 6, No. 1, pp. 42-53.
Programmable Calculators in Engineering Education--One Approach.

Personal computing presents many opportunities to introduce real world problems into the classroom, but most classrooms lack PCs for each student. The programmable calculator offers a cheap, universally available tool, with the power of a PC, to exploit the opportunities of personal computing. Now the student can concentrate on how to apply new mathematical principles to real world applications. The programmable calculator has successfully been integrated into a linear algebra course at the University of Kansas. This has changed the course.
Patient selection for laparoscopic myomectomy

Abstract Study Objective. To determine if preoperative criteria could select patiens who were likely to be managed successfully by laparoscopic myomectomy. Design. Prospective. Setting. Two community hospitals. Patients. Premenopausal women who had symptomatic uterine myomata and met the following crieteria underwent laparoscopic myomectomy: uterine size less than or equal to 14 weeks after 12 weeks of gonadotropin-releasing hormone (GnRH) agonist therapy; no individual myoma larger than 7 cm; no leiomyoma near the uterine artery, or near the tubal cornua if fertility was desribed; and at least 50% of the leiomyoma subserosal, to be accessible and to allow adequate repair of the myometrium through the laparoscope. Interventions. Laparoscopic assessment of the pelvis and laparoscopic myomectomy. Measurements and Main Results. Forty-one patients entered the study: 23 met the selection criteria and were accepted for laparoscopic myomectomy, but 4 were excluded during laparoscopic assessment of the pelvis. Clinical examination or initial sonogram correctly predicted successful laparoscopic myomectomy in 13 of the 19 women. After 3 months of GnRH agonist therapy, clinical examination or sonogram identified four additional candidates. In six patients in whom the optimum approach was still uncertain, laparoscopic assessment found two additional appropriate candidates for laparoscopic myomectomy. Nineteen patients underwent the procedure without the need to convert to laparotomy. None experienced any complications. Conclusions. Careful patient selection can decrease the likelihood of inappropriate performance of laparoscopic myomectomy and avoid the need to convert to laparotomy.
Organizing Internet resources: teaching cataloging standards and beyond

Recognizing changes in the information environment and related changes in cataloging standards, Catholic University of America’s LIS program adopted a strategy to offer students three levels of knowledge in organizing Internet resources. In the basic cataloging course, the instructor raises student awareness of Internet resources cataloging and metadata through demonstrations and discussions. In the advanced cataloging course, students apply cataloging standards and Dublin Core to Internet resources and selected types of material, and consider issues related to the implementation of metadata standards. In the advanced Internet resources organization course, students obtain hands‐on practice in creating electronic pathfinders and using metadata schemes such as Dublin Core, text encoding initiative (TEI), and encoded archival description (EAD). The instructor’s objectives are to broaden students’ understanding of the types of resources that need to be organized, give students knowledge and skills for the organization of digital resources, and prepare them to redefine cataloging in the twenty‐first century.
Interaction between the retinoid X receptor and transcription factor IIB is ligand-dependent in vivo.

The retinoid X receptor (RXR) influences gene activation through heterodimeric and homodimeric association with DNA and associates with TATA binding protein, TAF110, and cAMP response element-binding protein-binding protein; yet the molecular mechanisms responsible for gene activation by RXRs remain incompletely defined. Since the general transcription factor IIB (TFIIB) is a common target of sequence-specific transcriptional activators, we suspected that RXR might regulate target genes via an interaction with TFIIB. Co-immunoprecipitation, far Western analysis, and glutathioneS-transferase binding studies indicated that murine RXRβ (mRXRβ) was capable of binding to human TFIIB in vitro. Functional analysis with a dual-hybrid yeast system and cotransfection assays revealed the interaction of mRXRβ with TFIIB to be ligand-dependent in vivo. Truncation experiments mapped the essential binding regions to the carboxyl region of mRXRβ (amino acids (aa) 254–389) and two regions in the carboxyl region of TFIIB (aa 178–201 and aa 238–271). Furthermore, the Δ390–410 mRXRβ mutant bound to TFIIB in vitro but was not active in the dual-hybrid yeast system, suggesting that the extreme carboxyl region of RXR was required for in vivo interaction with TFIIB. These data indicate that interaction of mRXRβ with TFIIB is specific, direct, and ligand-dependent in vivo and suggest that gene activation by RXR involves TFIIB.
Research on Adult Learning and Memory: Retrospect and Prospect.

Abstract It is argued that whether the course of cognitive development is characterized by growth, stability, or decline is less a matter of “fact” than a matter of the metamodel on which the theories and data are based. Three historical shifts in basic research on adult learning and memory are reviewed. The associative approach, dominant until the late 1950s, is rooted in the mechanistic metamodel. Within this approach, learning and memory are seen as the formation and dissolution of stimulus-response bonds. The associative approach has projected an irreversible decrement view of aging and learning/memory performance. The information processing approach, dominant from the early 1960s until the present, is rooted in the organismic metamodel. Within this approach, learning and memory are governed by storage structures and control processes, and active processing on the part of the learner is emphasized. The information processing view has projected a decrement with a compensation view of aging and learning/memory performance. Finally, it is argued that a contextual approach is emerging in the present historical context. A contextual perspective appears to emphasize the activities of perceiving, comprehending, and remembering rather than encoding, storage, and retrieval. Acquisition is seen as involving the articulation of input with past experience which sets the boundary conditions for perceiving and comprehending the new material. This differentiation and integration are viewed as occurring within a hierarchy of levels which reflect wider and wider contexts. Remembering is seen as the reconstruction of previous events. Event reconstruction depends, in large measure, on the extent to which original events are differentiated from and integrated with past experience during acquisition. In addition, event reconstruction also depends on events occurring following acquisition. Such a contextual perspective on acquisition and remembering leads to several suggestions for examining these activities during adulthood including an emphasis on meaning, broad contexts, and multiple influences on cognitive development.
Effect of Prenatal Dexamethasone Administration: Fetal Rabbit Intestinal Nutrient Uptake and Disaccharidase Development

Abstract To examine the effect of prenatal steroids on fetal intestinal maturation, eight pregnant rabbits received either dexamethasone (Dex) or saline (Cont) on Days 25-27 of a 31-day gestation. As the rabbit provides a model of growth retardation based on uterine position, fetuses were identified as favored (Fav) or runt(Runt), generating four study groups: ContFav, ContRunt, DexFav, and DexRunt. On Day 31 the small intestinal uptake of glucose and proline was measured by an everted sleeve technique. Additionally, lactase and maltase activity was determined. Small intestinal length and nutrient uptake was significantly increased in the Dex fetuses. Control runts had a trend to decreased levels of nutrient uptake when compared to their favored counterparts. This trend reversed in the Dex fetuses with runt nutrient uptake surpassing that of the favored fetus. A trend to increased enzyme activity of both lactase and maltase was demonstrated. This report provides the first description of maternal steroid administration causing a marked increase in fetal small intestinal length and glucose and praline absorption in an in vivo model of intrauterine growth retardation.
Comparison of the second-harmonic response from Ag(111) in UHV and solution

Abstract The rotational anisotropy in the SH response from Ag(111) has been examined and compared for this surface in UHV and in an electrochemical environment. A remarkable similarity in the SH response is found for the surface examined in the two environments. The results for both 1064 and 532 nm incident wavelengths are reported.
Immunochemical properties of junctional and extrajunctional acetylcholine receptor.

Abstract Immunological assays were performed to compare two distinct forms of the nicotinic acetylcholine receptor (AChR): junctional (JR) and extrajunctional receptor (EJR). Antibodies from myasthenia gravis patients' sera inhibited the binding of [125I]α-bungarotoxin (BGT), to EJR more effectively than binding to JR. Immunological differences between JR and EJR were confirmed by other assay methods. In all cases, EJR appeared to have antigenic determinants not found on JR. It was established that enzymatic removal of carbohydrates from EJR caused it to more closely resemble JR. Thus differences between JR and EJR may be due, in part, to carbohydrate residues found on EJR that are absent on JR. The extent of antibody binding to EJR was examined by gel filtration methods. Immunochemical studies of bands from SDS gels showed that antibodies are present in myasthenic serum which react with the 3 subunits (42, 53, 64 kdaltons) of AChR to varying degrees.
A study of the tonsillar developments in the lingual region of anurans

In this study the problem of the tonsil is considered in anurans. The common toad (family Bufonidae) is used as the type, and representative species of the other families are compared. In each species representative stages beginning before transformation were selected, and the lingual region of each was sectioned. Some thyroid-fed toad tadpoles which had prematurely transformed were examined. The investigations led to the following conclusions: 1 Accumulations of lymphocytes occur in all the families except Hylidae. 2 A pair of tonsils located on either side of the tongue appear before transformation in Bufo, and persist, increasing in size through old age. 3 This pair has its developmental origin at or near the cephalic end of pouch II. In no other species examined do the tonsils appear as early; in almost all forms the accumulations are inconstant in occurrence, as are also some in Bufo. 4 The cells of the ‘tonsils’ are lymphocytes of varying sizes. They arise from the mesenchyme; later their accumulations become sites of lymphopoiesis. 5 This type of lympho-epithelial mass is simple in structure and has a greatly thickened epithelium, due to extensive infiltration by lymphocytes. In the connective tissue the vascular supply is abundant. 6 The differentiation of lymphocytes may be due to a factor of strain, arising through adjustments made during metamorphosis. 7 Thyroid-fed toad tadpoles transform, apparently without developing tonsils.
Toddler language and play in the second year: Stability, covariation and influences of parenting.

This paper reports the findings of a prospective longitudinal study of the development of representation and communication in toddlers from middle-class Caucasian families. Toddler language and pla...
A production engineered power transistor

This paper discusses the factors involved in the design of an alloy-junction power transistor. Attention is given to the problems of heat dissipation, sealing, collector cut-off current, voltage breakdown and current gain. The mechanical features which result in reproducibility, reliability, and low cost are illustrated. Tolerances and distribution of parameters are discussed and related to the design characteristics. A survey of the test procedure is given.
Characterization of flash γ-ray detectors that operate in the Trad/s range☆

Abstract Compton-diode detectors, scintillator-photodiode detectors, and Cherenkov-photodiode detectors, designed to measure the intense pulsed bremsstrahlung field of HERMES III, are described and characterized in the field of HERMES III. Measurements and modeling show that (1) the Compton-diode detector measures dose rate and is capable of linear operation up to 2.5×1012 rad/s, (2) the scintillator-photodiode detector measures dose rate only when the rate is less then 2×1011 rad/s, and (3) the Cherenkov photodiode detector can be used o place limits on the radiation pulse over the range ∼ 2.5×1010 to ∼ 2.5×1012 rad/s. A by-product of the measurements and modeling is the determination of the temporal behavior of the forward field of HERMES III near the beam axis.
Interactions between HIV1 Nef and Vacuolar ATPase Facilitate the Internalization of CD4

CD4 is the primary receptor for the human immunodeficiency virus (HIV). Nef is an accessory protein of HIV that decreases the expression of CD4 on the surface of infected cells. In this study, we identified the Nef binding protein 1 (NBP1), which interacts specifically with Nef in vitro and in vivo. Since it shares sequence similarity with the catalytic subunit of the vacuolar ATPase (V-ATPase) and complements the loss of this VMA13 gene in yeast, NBP1 is the human homolog of Vma13p. Direct interactions between Nef and NBP1 were correlated with the ability of Nef to internalize CD4. The expression of the antisense NBP1 abrogated these effects. We conclude that NBP1 helps to connect Nef with the endocytic pathway.
Mechanism of Action of Antiarrhythmic Agents: Focus on Propafenone

Propafenone is a new antiarrhythmic compound that has an unusual spectrum of pharmacological actions. Its dominant action in cardiac muscle is to block the fast sodium channel with slow onset and offset kinetics. Thus it has a marked depressant effect on conduction with a modest effect in prolonging the effective refractory period in fibers that are fast-channel dependent. In addition, it has beta-blocking and calcium-channel blocking actions that are likely to affect its overall spectrum of activity. Propafenone should be effective in suppressing both ventricular as well as supraventricular arrhythmias.
SU(5) Higgs problem with adjoint + vector representations

Recently Kim has given a general method, using group-invariant orbit parameters, for determining the energy and residual symmetry of the Higgs potential minimum. In this paper we illustrate the method by working out the case of a quartic SU(5) Higgs potential with 5 and 24 higgsons. In this method the Gell-Mann-Slansky conjecture concerning possible little groups of the potential minimum takes a geometric form, which is verified for our case. The results are used to discuss the hierarchical symmetry breaking of SU(5) grand unification theory. We generalize our results to the SU(N) adjoint + vector models, which are all closely related.
Oral Two-Point Discrimination: Further Evidence of Asymmetry on Right and Left Sides of Selected Oral Structures

2-point discrimination thresholds were established on 13 test sites (the midline, right, and left sides of the upper lip, lower lip, tongue tip, and tongue dorsum, and on the finger tip) in each of 14 Ss. A total of 10 thresholds, 5 ascending and 5 descending, were obtained at each site. It was found that all Ss exhibited evidence of asymmetry in their 2-point limen values between the right and left sides of at least one of the 4 oral structures tested. The results provide further support for McCall and Cunningham's (1971) proposed theory of “sensory sidedness” as a normal neurological phenomenon of the tactile sensory system.
Dose-dependency of MBP-induced demyelination in the guinea pig.

Abstract The pathology of experimental allergic encephalomyelitis (EAE) induced by bovine myelin basic protein (MBP) has been examined in the guinea pig with a series of doses ranging from 37.5 μg to 600 μg. This was to investigate whether the previously demonstrated lack of demyelinative effect by MBP was dose-related. At all doses tested, MBP induced clinical disease. Inflammation was the major feature of lesions in all animals. However, no demyelination was seen when 75 μg MBP or less was given. At higher doses (150 μg upwards), MBP always induced intense inflammation but demyelination was encountered inconsistently. These observations support the contention that in addition to an immune response to MBP, other factors contribute to autoimmune demyelination.
Three-Dimensional Modeling of the Brain's ECS by Minimum Configurational Energy Packing of Fluid Vesicles

The extracellular space of the brain is the heterogeneous porous medium formed by the spaces between the brain cells. Diffusion in this interstitial space is the mechanism by which glucose and oxygen are delivered to the brain cells from the vascular system. It is also a medium for the transport of certain informational substances between the cells (called volume transmission), and for drug delivery. This work involves three-dimensional modeling of the extracellular space as void space in close-packed arrays of fluid membrane vesicles. These packings are generated by minimizing the configurational energy using a Monte Carlo procedure. Both regular and random packs of vesicles are considered. A random walk algorithm is then used to compute the geometric tortuosities, and the results are compared with published experimental data. For the random packings, it is found that although the absolute values for the tortuosities differ, the dependence of the tortuosity on pore volume fraction is very similar to that observed in experiment. The tortuosities we measure are larger than those computed in previous studies of packings of convex polytopes, and modeling improvements, which require higher resolution studies and an improved modeling of brain cell shapes and mechanical properties, could help resolve remaining discrepancies between model simulations and experiment. It is also shown that the specular reflection scheme is the appropriate technique for implementing zero-flux boundary conditions in random walk simulations commonly encountered in diffusion problems.
Outpatient computer-based 32-hour esophageal pH studies teletransmitted to a central esophageal laboratory.

• Using a computer-based 32-hour esophageal pH system with a small patient-worn digital recording computer, outpatient studies are performed in the physiologic environment of the patient's workplace and home. Samples are taken at 15-s intervals, and the pH data stored in this computer are then fed into the main computer in the Central Esophageal Laboratory for analysis, scoring, printing out, and storage. Satellite esophageal laboratories located in regional hospitals, clinics, and physicians' offices conduct pH studies by telecommunication, using antimony electrodes, a recording computer, and a modem to transmit data to the main computer for high-quality computer analysis. One main computer and associated personnel serve multiple satellite stations. This maintains patient-physician relationships and is highly cost-effective. ( Arch Intern Med 1985;145:1617-1619)
Predictors and Effects of Training on an Online Health Education and Support System for Women with Breast Cancer

Many breast cancer patients currently turn to Internet-based education and support to help them cope with their illness. This study explores the role of training in influencing how patients use a particular Interactive Cancer Communication System (ICCS) over time and also examines what pre-test characteristics predict which people are most likely to opt in or out of training in the first place. With use of pre-test survey and unobtrusive individual records of ICCS system use data (N = 216), nonparametric tests revealed that only having a later stage of cancer predicted whether or not patients participated in training. Results indicated that participating in training was a significant predictor of higher levels of using the CHESS system. In particular, the repeated measures analysis of covariance found the significant interaction as well as main effect of group (i.e., training vs. no training) and time (i.e., individual's CHESS usages at different times) in interactive and information CHESS services, suggesting that 1) the training group has a higher level of usage than the no training group, 2) both of the groups' usage decreased over time, and 3) these joint patterns hold over time. Practical guidelines for future ICCS campaign implementation are discussed.
Lattice translates of a polytope and the Frobenius problem

This paper considers the “Frobenius problem”: Givenn natural numbersa1,a2,...an such that their greatest common divisor is 1, find the largest natural number that is not expressible as a nonnegative integer combination of them. This problem can be seen to be NP-hard. For the casesn=2,3 polynomial time algorithms, are known to solve it. Here a polynomial time algorithm is given for every fixedn. This is done by first proving an exact relation between the Frobenius problem and a geometric concept called the “covering radius”. Then a polynomial time algorithm is developed for finding the covering radius of any polytope in a fixed number of dimensions. The last algorithm relies on a structural theorem proved here that describes for any polytopeK, the setK+ℤh={x∶x∈ℝn;x=y+z;y∈K;z∈ℤn} which is the portion of space covered by all lattice translates ofK. The proof of the structural theorem relies on some recent developments in the Geometry of Numbers. In particular, it uses a theorem of Kannan and Lovasz [11], bounding the width of lattice-point-free convex bodies and the techniques of Kannan, Lovasz and Scarf [12] to study the shapes of a polyhedron obtained by translating each facet parallel, to itself. The concepts involved are defined from first principles. In a companion paper [10], I extend the structural result and use that to solve a general problem of which the Frobenius problem is a special case.
Zone Refining High-Purity Germanium

The effects of various parameters on germanium purification by zone refining have been examined. These parameters include the germanium container and container coatings, ambient gas and other operating conditions. Four methods of refining are presented which reproducibly yield 3.5 kg germanium ingots from which high purity (?NA - ND? ?2 × 1010 cm-3) single crystals can be grown. A qualitative model involving binary and ternary complexes of Si, 0, B, and Al is shown to account for the behavior of impurities at these low concentrations.
Borrelia burgdorferi-Infected, Interleukin-6-Deficient Mice Have Decreased Th2 Responses and Increased Lyme Arthritis

Recently, interleukin (IL)-6 was shown to be one of the earliest factors that trigger the differentiation of naive T cells into effector Th2 cells in vitro. Lyme arthritis was studied in IL-6-deficient mice, since joint inflammation is influenced by the T helper cell response against Borrelia burgdorferi. Arthritis incidence increased in B. burgdorferi-infected IL-6-deficient mice compared with that in controls. Furthermore, splenocytes of B. burgdorferi-infected IL-6-deficient mice produced significantly less IL-4 in response to Borrelia antigens than did C57BL/6 (B6) mice, and B. burgdorferi-specific IgG2b levels were significantly reduced in IL-6-deficient mice at 60 days of infection. These results extend previous in vitro observations by demonstrating an in vivo role for IL-6 in the differentiation of CD4 T cells toward a Th2 phenotype and further show that CD4 T cell responses influence murine Lyme arthritis.
HCI in education

The use of technology in education is burgeoning, especially in terms of distance and online education. At first, it appears that the tools used to support courses on line are simply tools used for video conferencing, EDI, and the like. Further investigation seems to support the idea that systems that support courses on line are qualitatively different from systems that support business activities or even a normal web site.When the organizers of the special interest group on Usability in Online/Distance Learning at CHI 99 were unable to attend, the group who attended took over the SIG and discussed topics having to do with usability in distance education. The purpose of this special interest group is to follow up on the discussion that was started there in a more formal manner.