cssi/SciSciGPT-SciSciNet huggingface dataset:
Boundary Representation Models: Validity and Rectification

Model validity, especially of manifold boundary representation (B-rep) models, has long been recognized as an important problem. This paper reviews issues on model validity of existing models. In particular, we present a set of sufficient conditions for representational validity of a typical B-rep data structure; we propose a rectify-by-reconstruction approach to the B-rep model rectification problem, and present results on the inherent complexity of the corresponding boundary reconstruction problem. Further, we develop the concept of an interval solid model, associated with a solid, for achieving numerical robustness. Finally, we present a set of sufficient conditions so that an interval solid model is “approximately equal” to its associated solid.
Abraham Guz (1929–2014)

How do you describe a giant? As a person of abnormally great stature; above the usual size; or someone with much greater powers than the average person? Abraham Guz (‘Abe’) was not a tall man, but he was a scientific giant with an absolute desire to understand and find the scientific truth. This drive led him to make many original contributions in respiratory and cardiovascular physiology. Indeed, a simple literature search produces over 250 peer reviewed papers spanning some 50 years, the top 25 of which have been quoted over 2500 times. Moreover, most of his outstanding work was published in The Journal of Physiology, and we received it with gratitude because it was always insightful and ahead of its time. Many will argue that counting citations is a poor measure of scientific endeavour and I suspect Abe himself would certainly agree. However, this approach did provide us with a place to start when faced with the task of bringing together Abe's huge and varied scientific contributions.
Intraoperative Molecular Imaging of Lung Adenocarcinoma Can Identify Residual Tumor Cells at the Surgical Margins

During lung surgery, identification of surgical margins is challenging. We hypothesized that molecular imaging with a fluorescent probe to pulmonary adenocarcinomas could enhance residual tumor during resection. Mice with flank tumors received a contrast agent targeting folate receptor alpha. Optimal dose and time of injection was established. Margin detection was compared using traditional methods versus molecular imaging. A pilot study was then performed in three humans with lung adenocarcinoma. The peak tumor-to-background ratio (TBR) of murine tumors was 3.9. Fluorescence peaked at 2 h and was not improved beyond 0.1 mg/kg. Traditional inspection identified 30 % of mice with positive margins. Molecular imaging identified an additional 50 % of residual tumor deposits (p < 0.05). The fluorescent probe visually enhanced all human tumors with a mean TBR of 3.5. Molecular imaging is an important adjunct to traditional inspection to identify surgical margins after tumor resection.
Retinol binding protein as a surrogate measure for serum retinol: studies in vitamin A–deficient children from the Republic of the Marshall Islands

Background: Serum retinol is transported by retinol binding protein (RBP), which has one high-affinity binding site for retinol; consequently, the molar ratio of retinol to RBP in the circulation is 1 to 1. In vitamin A deficiency (VAD), both serum retinol and RBP decline. However, the retinol-RBP relation has not been well studied in populations with a high incidence of severe VAD. Objective: The purpose of this study was to determine whether RBP is a good surrogate for serum retinol at the very low retinol concentrations encountered in VAD. Design: The stoichiometric relation between retinol and RBP was studied in 239 Marshallese children: 65 with severe VAD (≤0.35 μmol retinol/L), 94 with moderate VAD (0.36-0.70 μmol retinol/L), and 80 with vitamin A sufficiency (>0.70 μmol retinol/L). Results: Excellent correlation between retinol and RBP (r = 0.94) was observed across all retinol concentrations. Severe VAD was predicted with 96% sensitivity and 91% specificity on the basis of an RBP cutoff of ≤0.48 μmol/L, whereas moderate VAD was predicted with 87% sensitivity and 98% specificity on the basis of an RBP cutoff of ≤0.70 μmol/L. Conclusions: The use of RBP results in the classification of essentially the same children with VAD as does retinol, and RBP is an excellent surrogate for serum retinol. Considering the relative ease of measuring RBP with immunodiagnostic kits compared with that of serum retinol by HPLC, the use of RBP concentrations to assess VAD may be particularly advantageous in field settings. Consequently, measuring RBP concentrations may be a practical alternative to measuring serum retinol in population surveys assessing the prevalence of VAD.
Regulation of phospho(enol)-pyruvate- and oxaloacetate-converting enzymes in Corynebacterium glutamicum

The presence and properties of the enzymes involved in the synthesis and conversion of phospho(enol)pyruvate (PEP) and oxaloacetate (OAA), the precursors for aspartate-derived amino acids, were investigated in three different Corynebacterium strains. This study revealed the presence of both PEP carboxykinase 0.29 μmol·min−1·mg−1 of protein [units (U)·mg−1] and PEP synthetase (0.13 U·mg−1) in C. 2 glutamicum as well as pyruvate kinase (1.4 U·mg−1) and PEP carboxylase (0.16 U·mg−1). With the exception of PEP carboxykinase these activities were also present in glucose-grown C. flavum and C. lactofermentum. Pyruvate carboxylase activity was not detected in all three species cultivated on glucose or lactate. At least five enzyme activities that utilize OAA as a substrate were detected in crude extracts of C. glutamicum: citrate synthase (2 U·mg−1), malate dehydrogenase (2.5 U·mg−1), glutamate: OAA transaminase (1 U·mg−1), OAA-decarboxylating activity (0.89 U·mg−1) and the previously mentioned PEP carboxykinase (0.29 U·mg−1). The partially purified OAA-decarboxylase activity of C. glutamicum was completely dependent on the presence of inosine diphosphate and Mn2+, had a Michaelis constant (Km) of 2.0mm for OAA and was inhibited by ADP and coenzyme A (CoA). Examination of the kinetic properties showed that adenine nucleotides and CoA derivatives have reciprocal but reinforcing effects on the enzymes catalyzing the interconversion of pyruvate, PEP and OAA in C. glutamicum. A model for the regulation of the carbon flow based on these findings is presented.
Integers with dense divisors 2

Abstract Let 1=d1(n) x⩾t⩾ exp {( log 2 x) 5/3+e } , we have D(x,t)=x d(w) 1+O 1 log t , where w= log x/ log t , and d(w) is a continuous function which satisfies d(w)≍1/w for w⩾1. We also consider other counting functions closely related to D(x,t).
Prophylactic antibiotics are not indicated in clean general surgery cases

Abstract Background: In assigning risk of infection, the traditional wound classification system has been replaced by the National Nosocomial Infection Surveillance (NNIS) system. NNIS classification is determined by procedure length, wound cleanliness, and ASA status. To date, no prophylactic antibiotic guidelines have been proposed for the NNIS system. Methods: Clean general surgery cases were retrospectively reviewed in our hospital for infection and prophylactic antibiotic use. These cases were then stratified per the NNIS system. Results: One thousand twenty-three clean general surgery cases had 16 (1%) surgical site infections. The infection rate in NNIS class 0, 1, and 2 cases not given prophylactic antibiotics was 1.21%, 3.03%, and 0%, respectively. The infection rate in NNIS class 0, 1, and 2 cases given prophylactic antibiotics was 0.94%, 2.44%, and 6.67%, respectively. Conclusions: No statistically significant decrease in infection rate was demonstrated by us using prophylactic antibiotics, regardless of the NNIS classification in clean general surgery cases.
Unemployment rates in postbellum America: 1869–1899

Abstract An annual series for U.S. unemployment rates for the period 1869–1899 is estimated. The series reflects the cyclical economic fluctuations of the period clearly, including the protracted depressions of the 1870s and 1890s. It indicates that these depressions were much less severe than the Great Depression of the 1930s, but somewhat more severe than the depressed periods of the post-World War II years. Annual series for labor force, employment, and unemployment also are presented.
An Update on Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease that ultimately leads to right heart failure and death. PAH is defined as a mean pulmonary arterial pressure ≥ 25 mmHg with a pulmonary capillary wedge pressure ≤ 15 mmHg at rest. The diagnosis of PAH is one of exclusion; diagnostics include an extensive history, serology, chest radiograph, pulmonary function tests, ventilation/perfusion scan, transthoracic echocardiogram, and right heart catheterization. Treatment and care of patients with PAH can be complex. Therefore, the nurse practitioner is an integral member of the health care team caring for PAH patients, helping to ensure seamless care and support.
Hemodynamic Studies in Patients with 2M and 3M Starr-Edwards Prostheses: Evidence of Obstruction to Left Atrial Emptying

The hemodynamic findings in 28 patients with small (2M uncovered, 2M and 3M covered) Starr-Edwards mitral prostheses are compared with the findings in 12 patients with larger (3M and 4M uncovered) prostheses. Although most patients with the smaller prostheses evidenced both clinical and hemodynamic improvement after operation, the majority continued to have a significant left atrial-left ventricular pressure gradient and an elevated left atrial pressure at rest. During exercise the gradient increased, and left atrial pressure was abnormally elevated in each patient. The hemodynamic findings were decidedly less satisfactory in patients with smaller prostheses than in patients in whom it had been possible to insert larger prostheses. It is concluded that the major site of obstruction to left atrial emptying in patients with smaller prostheses is the small primary orifice of the prosthesis present at the time of insertion. Further narrowing of the primary or secondary orifices by thrombus and/or tissue ingrowth probably contributes to the obstruction in some patients.
Beyond bereavement support group meetings: exploring outside social contacts among the members.

Abstract This article examines the extent to which bereavement support group participants engage in social interaction with fellow group members outside of the meetings, demographic influences on outside contact, and the relationship between this social interaction and bereavement outcomes. Data are presented from a longitudinal study that included 144 recently bereaved spouses between the ages of 51 and 89 who participated in a support group intervention. During the course of the study the majority of the participants had contact with other group members in addition to the scheduled meetings even though the group leaders did not encourage outside contact. Although the frequency of the interaction was only moderate, the support group participants reported feeling relatively close to their fellow group members. Men were as likely as women to have outside contact but they delayed in doing so. Those who engaged in outside contact were slightly more depressed, experienced more stress, and were more lonely at ...
Coupling interval and types of ventricular ectopic activity associated with ventricular runs

Repetitive 10-hour ECG recordings of 289 patients obtained within a year after myocardial infarction were analyzed for the presence of ventricular runs, and their association with various types of ventricular ectopic activity (VEA), average rate of premature ventricular complexes (PVCs), and coupling interval of PVCs initiating the runs. Tapes which contained complex VEA (bigeminy, multiform PVCs, couplets, or runs), early PVCs (coupling interval less than 400 msec), or late PVCs (coupling interval greater than 600 msec) had a substantially higher average PVC rate than those without them. The occurrence of ventricular runs was significantly more likely in tapes having other complex VEA or late PVCs than in those without them, and when tapes were stratified by PVC rates the presence of these dysrhythmias appeared to have an independent predictive value for the occurrence of runs. In contrast, the influence of early PVCs on the occurrence of runs was rather minimal, and this seemed to be related to their common association with the PVC rate. Furthermore, a larger percentage of isolated PVCs had coupling intervals between 400 msec and 600 msec, and most couplets (77%) and runs (67.8%) were initiated by PVCs with coupling intervals in this range. However, the proportion of either short (less than 400 msec) or long (greater than 600 msec) coupling interval PVCs initiating couplets or runs was significantly higher than those with intermediate coupling intervals (between 400 and 600 msec).
Relationship Between the Regulation of Enkephalin-Containing Peptide and Dopamine β-Hydroxylase Levels in Cultured Adrenal Chromaffin Cells

Adrenal medullary chromaffin cells were maintained under conditions known to increase their cellular levels of enkephalin-containing peptides and the effects of these treatments on another chromaffin vesicle component, dopamine beta-hydroxylase, were examined. Catecholamine-depleting drugs, such as tetrabenazine, and cyclic nucleotide-elevating drugs, including forskolin, 8-bromo-cyclic AMP, and theophylline, increase chromaffin cell enkephalin-containing peptide levels but fail to increase dopamine beta-hydroxylase. In contrast, insulin treatment increases the levels of both enkephalin-containing peptides and dopamine beta-hydroxylase. The increased amounts of enkephalin-containing peptides produced by tetrabenazine and by insulin are stored in subcellular particles with properties identical to chromaffin vesicles on density-gradient centrifugation. These results suggest that following insulin treatment chromaffin cells synthesize new chromaffin vesicles with a full complement of enkephalin-containing peptides, but that after treatment with catecholamine-depleting or cyclic nucleotide-related agents enkephalin-containing peptides can be inserted into preexisting vesicles or that new vesicles, made as a part of the normal turnover of cellular components, contain elevated peptide levels.
Violating Student Expectations: Student Disclosures and Student Reactions in the College Classroom

Expectancy violations theory (EVT; Burgoon & Hale, 1988) was the theoretical lens used in this study about perceptions of appropriate and inappropriate student disclosures in the college classroom. Participants (N = 211) were randomly assigned to report on either (a) an inappropriate or (b) an appropriate disclosure and the frequency, relevance, negativity, expectedness of the disclosure, and likeability and perceived academic competence of a student discloser. Results indicate that student disclosures are inappropriate when they happen frequently, are negative, irrelevant to course materials, or violate student expectations for classroom norms. Generally, disclosers who violate expectations are rated lower in liking and perceived as less competent students by their classmates.
Parental perceptions and morbidity: tracheostomy and Pierre Robin sequence.

Summary Objective: Evaluate parental perceptions associated with tracheostomy morbidity and quality of life in the management of Pierre Robin Sequence (PRS). Study Design: Retrospective review/survey. Methods: 42 Pierre Robin patients were identified, records were reviewed and airway assessments evaluated relative to airway compromise. Twenty patients had undergone tracheostomy. Perceptions of quality of life/morbidity related to tracheostomy were assessed using parental surveys. Results: 31/41 (76%) patients participated in the survey. 15/31 (48%) of survey participants required tracheostomy and were decannulated after a mean of 28 months. Of the patients who had undergone tracheostomy, 10/15 (67%) had isolated Pierre Robin (iPRS) and the remaining 5/15 (33%) had syndromes associated with Pierre-Robin (sPRS). 9/10 (90%) iPRS and 4/5 (80%) sPRS families’ expectations were met regarding expected duration of tracheostomy although 3/5 (60%) sPRS, and 8/10 (80%) iPRS described the overall experience as difficult. Of the 2/15 patient’s families who were dissatisfied 1 patient had iPRS and the other sPRS. 9/15 (60%) required multiple (3) hospitalizations. 3/13 (23%) reported airway problems after decannulation and 2/15 (13%) remained tracheostomy dependent at the time of survey. Prolonged tracheostomy duration represented a significant parental concern. Conclusions: A subset of patients required extended duration of tracheostomy; some continued to have airway problems after decannulation and/or distraction. Although some patients benefit from early mandibular distraction other Pierre Robin patients have multi-level obstruction requiring additional therapies and often tracheostomy. Parental concerns and perceptions relative to tracheostomy have not been
Parasites and diarrhea. II: Helminths and diarrhea

Infection with intestinal helminths is extremely coninion worldwide. Nearly a fourth of all people are infected with Ascaris and almost as many with hookworm and Xichuris.Virtually no intestinal worm has escaped the allegation of being a cause of diarrhea. Some, however, have never been implicated in a serious study. For example, controlled studies have identified Ascaris lumbricoides and hookworm in equal numbers in patients with and without diarrhea' and have found that diarrhea is no more frequent in those infected than in controls.'-4 In Part 1,' we discussed the role of various protozoans in diarrhea. In contrast to infections with intestinal protozoa, those with intestinal helminths are less common in returning travelers. The frequency of infection is correlated with both the duration of travel and the geographic area visited.' Table 1 lists intestinal helminths and their association with diarrhea.
Crystal Structure of Escherichia coli L-Arabinose Isomerase (ECAI), The Putative Target of Biological Tagatose Production

Escherichia coli L-arabinose isomerase (ECAI; EC 5.3.1.4) catalyzes the isomerization of L-arabinose to L-ribulose in vivo. This enzyme is also of commercial interest as it catalyzes the conversion of D-galactose to D-tagatose in vitro. The crystal structure of ECAI was solved and refined at 2.6 A resolution. The subunit structure of ECAI is organised into three domains: an N-terminal, a central and a C-terminal domain. It forms a crystallographic trimeric architecture in the asymmetric unit. Packing within the crystal suggests the idea that ECAI can form a hexameric assembly. Previous electron microscopic and biochemical studies supports that ECAI is hexameric in solution. A comparison with other known structures reveals that ECAI adopts a protein fold most similar to E. coli fucose isomerase (ECFI) despite very low sequence identity 9.7%. The structural similarity between ECAI and ECFI with regard to number of domains, overall fold, biological assembly, and active site architecture strongly suggests that the enzymes have functional similarities. Further, the crystal structure of ECAI forms a basis for indentifying molecular determinants responsible for isomerization of arabinose to ribulose in vivo and galactose to tagatose in vitro.
Improved peptide elution time prediction for reversed-phase liquid chromatography-MS by incorporating peptide sequence information

We describe an improved artificial neural network (ANN)-based method for predicting peptide retention times in reversed-phase liquid chromatography. In addition to the peptide amino acid composition, this study investigated several other peptide descriptors to improve the predictive capability, such as peptide length, sequence, hydrophobicity and hydrophobic moment, and nearest-neighbor amino acid, as well as peptide predicted structural configurations (i.e., helix, sheet, coil). An ANN architecture that consisted of 1052 input nodes, 24 hidden nodes, and 1 output node was used to fully consider the amino acid residue sequence in each peptide. The network was trained using ∼345 000 nonredundant peptides identified from a total of 12 059 LC−MS/MS analyses of more than 20 different organisms, and the predictive capability of the model was tested using 1303 confidently identified peptides that were not included in the training set. The model demonstrated an average elution time precision of ∼1.5% and was abl...
Single-station location of seismic events: a review and a plea for more research

Abstract Traveltime-based location methods are ineffective for locating regional seismic events which are recorded by few stations; however, the Comprehensive Test Ban Treaty (CTBT) makes it imperative that we monitor sparsely observed events. This paper reviews the current status of single-station location (SSL) methods—the location of seismic events using records from one three-component broadband digital station. We argue here that SSL methods may ultimately provide the most effective and economical means for monitoring small-magnitude (M∼3) seismic events over most of the earth. Potentially, station-event distance and focal depth may be determined accurately by utilizing broadband three-component data and matching observed and synthetic waveforms; station-event azimuth is determinable from the polarization of the P-wave arrival and P coda. However, more research is required before SSL methods become a practical alternative to traveltime-based methods. Currently, the most significant problem is that regional seismograms are strongly dependent on regional crustal structure. Thus, future research efforts should focus both on determining appropriate crustal models in specific regions, and also on improved methods for dealing with regional variations in crustal structure. A second important problem concerns location errors; with SSL they may involve 180° errors in station-event azimuth or other highly non-Gaussian `blunders'.
Abstract 2554: Constitutive short telomere length and lung cancer risk: a large case- control study.

Background: Telomeres plays a key role in the maintenance of chromosomal stability and integrity. Telomere dysfunction is a common crucial event in malignant transformation and tumorigenesis. Short telomere length in surrogate tissues (peripheral blood leukocytes, or PBLs) has been associated with increased risks of several cancers. In this study, we used a large case control study to evaluate the association of overall telomere length in PBLs with the risk of lung cancer. Methods: We measured the overall telomere lengths in PBLs using real-time quantitative PCR method in a large case-control study with 769 Caucasian lung cancer cases and 769 age, gender, and ethnicity matched healthy controls Wilcoxon rank sum test was used to compare the differences between case patients and control subjects. Unconditional multivariate logistic regression analysis was used to assess the association between telomere length and lung cancer risk. In addition, the effect of age, gender and smoking status was evaluated and correlation analyses between variables were performed. Results: As expected, telomere length was inversely correlated with age in both cases and controls. Lung cancer patients had significantly shorter overall telomere lengths (mean ± standard deviation: 1.20 ±0.37 versus 1.25 ±0.35 p =0.002) than controls, which was only evident in men (1.15 ±0.36 versus 1.24 ±0.36 p Conclusions: This is the largest epidemiological study to evaluate constitutive telomere length and lung cancer risk. Our data strongly support the role of telomere dysfunction in lung carcinogenesis, highlighting its specific interaction with smoking. Citation Format: Beatriz Sanchez-Espiridion, Jian Gu, David W. Chang, Joe Y. Chang, Charles Lu, Jack A. Roth, Xifeng Wu. Constitutive short telomere length and lung cancer risk: a large case- control study. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2554. doi:10.1158/1538-7445.AM2013-2554
Minimum-cost casing design for vertical and directional wells

The potential of casing cost reduction is investigated by use of an optimization technique. A simple recurrent computer procedure for the minimum-cost casing in vertical wells is derived. Simulation analysis reveals 24% casing cost reduction, as well as several special applications. A new model of the minimum-cost casing design in directional wells is developed. Directional data are used for casing load calculations; the the minimum-cost casing string is selected. An analysis of the effect of directional-well geometry and the borehole drag on the minimum casing cost is performed. This paper and the optimization computer program provide the casing designer with the complete cost-related information necessary to make the best decision.
The effect of age on Intestinal glucose transport in the chick (Gallus domesticus)

Abstract 1. 1. Intestinal 3-O methyl glucose transport was studied by the in vitro everted sac technique in chicks of various ages. 2. 2. Glucose transport was maximum in 1-week-old chicks and then decreased progressively with age. 3. 3. [U-14C]Glucose oxidation by isolated intestinal epithelial cells also decreased with age along with the DNA content of the cell preparations. 4. 4. Histological examination of the intestinal sections prepared from 1- and 8-week-old chicks showed that while the epithelial cell number decreased, thickness of the submucosal tissue increased with age. 5. 5. Oral 3-O-methyl glucose load given to 1- and 12-week-old chicks showed significantly greater intestinal absorption in the younger chicks. 6. 6. Our results suggest that glucose absorption in the chick decreases with age and that this is probably due to combined effects of decreased cellular performance, decreased cell number and an increase in submucosal tissue thickness.
Triphosphopyridine nucleotide-dependent enzymes in the developing spinal cord of the rabbit.

— Total lipid and the activity of five enzymes closely related to the generation of NADPH have been measured in the anterior horn region and dorsal columns of rabbit spinal cord during the period of rapid myelination. Lipid deposition progressed to a much greater extent in the dorsal columns than in the anterior horn region; however, the age at which one-half of the total adult level of lipid accumulated in both regions was the same, i.e. 19-20 days after birth. During the first 15 days of postnatal development of the dorsal columns, glucose-6-phosphate dehydrogenase changed in parallel with lipid content; however, in the anterior horn region changes in lipid were not accompanied by increases in glucose-6-phosphate dehydrogenase. In contrast to changes in glucose-6-phosphate dehydrogenase, the activity of malic enzyme increased in the anterior horn region but remained relatively constant in the dorsal columns during development. The activities of two other enzymes of the pentose phosphate pathway, 6-phosphogluconate dehydrogenase and transketolase, measured at various intervals after birth, did not directly parallel changes in the activity of glucose-6-phosphate dehydrogenase in the dorsal columns. In both areas of the developing spinal cord the activity of NADP+-dependent isocitrate dehydrogenase was greater than the activities of the other three dehydrogenases but it did not parallel changes in lipid content of either region. A relationship between the requirements for reducing equivalents and the activities of the four NADP+-dependent dehydrogenases is suggested by the finding that both areas of the adult spinal cord contained lower activities of these enzymes than those observed during the initial 26 days of development. The differences noted in the two areas of the spinal cord during development suggest that mechanisms for the generation of NADPH differ in gray and white matter.
The Trials of a Poor Middle School Trying to Catch Up in Mathematics: Teachers' Multiple Communities of Practice and the Boundary Encounters

This article details a 5-year evolution of a middle school mathematics faculty serving predominantly economically at-risk students. Faculty members worked to improve students' mathematics test scores, used a scripted curriculum, and integrated National Council of Teachers of Mathematics (NCTM) standards-based activities. Schools nationwide are transforming with the No Child Left Behind legislation, accountability mandates, and the NCTM standards. The demands on these teachers are typical of high-stakes systems. Drawing on Lave and Wenger's “community of practice” and Cobb, McClain, Lamberg, and Chrystal's extension, this article describes how teachers accommodate to the process of change and the group dynamics encountered within a school structure.
Males as Helpers: The Role of Sons, Relatives, and Friends

The informal helping networks of most frail elderly people are dominated by women. Men are also involved in helping older people, although most male caregivers are husbands. This paper examines the contributions of men other than husbands who provide assistance to a sample of community-based elderly people. Data were gathered through personal interviews with elders and their primary helpers at two points in time. Male helpers provide intermittent assistance with occasional tasks but less frequently undertake routine household chores. Some evidence indicates a shift toward female caregivers as the elder's functional capacity decreases over time.
Catheter ablation of ventricular tachycardia.

Endocardial lesions created by radiofrequency catheter ablation are relatively small and focal. The application of radiofrequency ablation to patients with structural heart disease and ventricular tachycardia is quite limited because the substrate for these tachycardias is often diffuse or difficult
Electron microscopy of the tana poxvirus

Abstract The fine structure of Tana virus, a poxvirus originally isolated from children in Kenya, has been studied by electron microscopy of infected rhesus embryonic monkey tissue cultures. The intracytoplasmic maturation of the virus has been analyzed and compared with that seen in Yaba-like disease (Y.L.D.), an epidermal pox disease of monkeys. Two types of virus factories have been distinguished, one of which appears to be responsible for formation of nucleoids, the other for virus membranes. Honeycombed crystals, cylindrical tubules, mitochondria in pairs or triplets, and myelin figures were also observed. The nuclei showed areas of decreased electron opacity. The development of Tana virus was identical with that of Y.L.D. virus. These findings are consistent with the hypothesis, based on serologic studies, that Tana poxvirus is identical with Y.L.D. virus but differs from a similar monkey poxvirus, the Yaba tumor virus.
Malignant lymphoma of the thyroid gland: A clinicopathologic study

This study reviews 21 cases of thyroid lymphoma diagnosed between 1969 and 1980. The thyroid gland was the primary site in all but two cases. The 20 patients with non-Hodgkin lymphoma had a mean age of 66 years, 75% were women, and all were Caucasian. A rapidly growing thyroid mass with hoarseness, dysphagia, and difficulty in breathing was the initial finding. Most patients had diffuse histiocytic lymphomas. Associated Hashimoto thyroiditis was found histologically in 57% of the cases. Using the immunoperoxidase stain method on tissue sections, intracytoplasmic monoclonal immunoglobulin was demonstrated in 5 of 15 cases. All but two patients received radiation therapy, and 13 received chemotherapy. The median survival was 8 months; 20% died of unrelated causes and 32% are alive (average duration: 27 months). Dissemination, after local control by radiation therapy, was the leading cause of death. The prognosis was better in men, in patients under the age of 65 years, and in those patients who, on biopsy, did not have involvement of the extrathyroid soft tissue or regional lymph nodes.
Modifying the Lambda Ratio to Functional Line Contacts

Lambda ratio, the lubricant film thickness divided by the composite roughness within an operating rolling element bearing, has been recognized for more than 25 years as an important contact parameter related to bearing performance, primarily fatigue life. This paper considers a simplified method of functional filtering within a bearing contact that provides a more appropriate composite roughness for a wider range of bearing sizes and loadings. The concept was tested with a series of regression models of standard and modified lambda ratios, including the uncoupled lambda parameters. The models were rated using three different statistical indices to assess how each model accounted for the variation present in a large collection of bearing test data. Presented at the 35th STLE/ASME Tribology Conference In Fort Lauderdale, Florida October 16–19, 1989
Regulation of cloned prolactin-inducible genes in pigeon crop.

Polyadenylated RNA from PRL-stimulated pigeon (Columba livia) crop was used as template to produce a cloned cDNA library in plasmids. The library was screened by differential hybridization against labeled nucleic acid populations representative of both unstimulated and PRL-stimulated crop tissue. By this method four independent clones coding for PRL-inducible mRNAs were identified. The regulation of these four genes ranged from modest (2- to 3-fold) to major (>70-fold). A clone designated DA4 was complimentary to the most markedly stimulated crop mRNA. This mRNA encoded a polypeptide with a molecular weight of 35,500 which corresponds with the major induced protein synthesized in vivo. Messenger RNADA4 stimulation was dose dependent showing maximal induction by ovine PRL systemic injections in the 200 μg/day range. Above this dose PRL was less effective. The onset of mRNADA4 accumulation after a single PRL injection was rapid with statistically significant levels occurring by 3 h. Several lactogenic type ...
Linezolid: The first oxazolidinone antimicrobial

Linezolid is the first of a new class of antimicrobial agents, the oxazolidinones, to be approved for clinical use in the United States and elsewhere. The drug is a totally synthetic compound, which lessens the likelihood of naturally occurring resistance mechanisms. It has excellent activity against virtually all important gram-positive pathogens, including methicillin-resistant staphylococci, penicillin-resistant pneumococci, macrolide-resistant streptococci, and vancomycin-resistant enterococci. Development of resistance to the compound has been infrequent thus far. Linezolid is 100% bioavailable, so it can be given in equal doses orally or parenterally. Its elimination half-life allows dosing twice per day, and alteration of drug dosage is not required in patients with impaired renal or hepatic function. Linezolid has approved indications for skin and soft tissue infections; lower respiratory tract infections; and vancomycin-resistant Enterococcus faecium infections, including cases with concurrent bacteremia. The drug has an acceptable profile of adverse events, but reversible myelosuppression has occurred in patients receiving high doses for more than 2 weeks.
Labeling of specific cysteines in proteins using reversible metal protection.

Fluorescence spectroscopy is an indispensible tool for studying the structure and conformational dynamics of protein molecules both in isolation and in their cellular context. The ideal probes for monitoring intramolecular protein motions are small, cysteine-reactive fluorophores. However, it can be difficult to obtain specific labeling of a desired cysteine in proteins with multiple cysteines, in a mixture of proteins, or in a protein's native environment, in which many cysteine-containing proteins are present. To obtain specific labeling, we developed a method we call cysteine metal protection and labeling (CyMPL). With this method, a desired cysteine can be reversibly protected by binding group 12 metal ions (e.g., Cd2+ and Zn2+) while background cysteines are blocked with nonfluorescent covalent modifiers. We increased the metal affinity for specific cysteines by incorporating them into minimal binding sites in existing secondary structural motifs (i.e., α-helix or β-strand). After the metal ions were removed, the deprotected cysteines were then available to specifically react with a fluorophore.
Stratigraphic response to saline lake-level fluctuations and the origin of cyclic nonmarine evaporite deposits: The Pleistocene Blanca Lila Formation, northwest Argentina

Stratigraphic analysis of Pleistocene nonmarine bedded evaporites in northwest Argentina elucidates the effect that episodic saline lake expansion and contraction have on the stratigraphic completeness of units deposited and preserved in a continental saline environment. Stratigraphic successions in these rocks contain features that relate uniquely to fluctuations in saline lake level. Bounding the top of each succession is a surface with evidence for an abrupt increase in water depth. Because sediment accumulation and stratal preservation vary spatially as a function of lake level, the degree of stratigraphic completeness varies among locations. These results have implications for attempts to extract the record of continental climate change from saline lake strata. Bedded evaporites in these strata accumulated in a saline lake characterized by a marginal zone of gypsum and ulexite with clastic interbeds and an accumulation of halite in the saline lake center. Four internally conformable successions of genetically related lithofacies assemblages are recognized. Each succession consists of a basal sandstone that is the initial accumulation of the lake-level rise and lake highstand. Overlying this sandstone are cyclic evaporite and fine-grained clastic deposits of the lake-level fall. These units are modified by desiccation-related processes resulting from lake contraction and desiccation around the lake margins. Subsequent lake-level rise resulted in subaqueous mechanical erosion of clastics and dissolution of interbedded evaporites. In more basinward regions, dissolution of evaporites occurred prior to accumulation of lake highstand units. In the saline lake center, the lake never dried up entirely, and evidence for partial lake desiccation is equivocal.
Methodological and operational issues in the construction of absence variables

Abstract Methodological studies have materially altered thinking about the nature of absence variables. Because of this research, the research community is now aware that absence variables frequently follow irregular data distributions [J. Appl. Psychol. 66 (1981) 574; J. Appl. Psychol. 74 (1989) 300]. Researchers have also been made aware that the reliability of absence metrics depends on the way the measures are configured [Pers. Psychol. 24 (1971) 463; J. Appl. Psychol. 66 (1981) 574]. What has received less attention are research design decisions (i.e., procedural and operational) impacting the psychometric properties of absenteeism variables. The current discussion focuses on the operational and methodological decisions researchers make that impact the measurement properties of absence variables.
Day-night and individual differences in response to constant-rate ranitidine infusion.

Twelve ulcer patients with inactive disease received constant-rate infusions of ranitidine, in doses of 6.25 and 10.0 mg/hr, during separate 24-h spans. Gastric pH and serum ranitidine concentrations were monitored. Serum ranitidine concentrations did not vary significantly after attainment of steady-state. For the group, gastric acidity was controlled above pH 4 during the day; however, at night, when gastric acid secretion was greatest under placebo conditions, ranitidine less effectively controlled gastric pH. There was individual variation in response to ranitidine. Patients (8/12) evidencing control of gastric acidity (pH ± 4) for at least 16 h when infused with ranitidine (6.25 mg/h) were considered re-sponders. Those (4/12) not so well controlled were designated poor responders. With parenteral infusion of 6.25, as well as 10.0 mg/h ranitidine, responders evidenced a relatively high 24-h mean pH and only minor day-night variation in gastric acidity. In contrast, poor responders were characterized b...
Corneal pseudomembrane from acute inflammatory response and fibrin formation to acute myeloid leukemic infiltrate.

Purpose To describe an unusual ocular manifestation of a patient with acute myeloid leukemia (AML). Design Observational case report. Methods A 59-year-old woman with a history of preleukemic myelodysplastic syndrome (MDS) and status post bone marrow transplant (BMT) complained of a sudden onset of poor vision associated with a corneal pseudomembrane. Ocular graft vs host disease was suspected, and the pseudomembrane was excised for histopathologic examination. Results The pseudomembrane showed myeloblasts admixed with an acute inflammatory response suggestive of the development of AML, a complication of MDS. Bone marrow examination confirmed the diagnosis of relapsing AML. Conclusions Acute myeloid leukemia could present as a pseudomembrane; thus, examination of relevant ocular tissue is recommended.
Thermal poly-alpha-amino-acids containing low proportions of aspartic acid.

Poly-alpha-amino acids /protenoids/ containing low proportions of aspartic acid synthesized by heating dry amino acids mixtures
Linguistic Markers of Stance in Early and Advanced Academic Writing: A Corpus-Based Comparison.

This article uses corpus methods to examine linguistic expressions of stance in over 4,000 argumentative essays written by incoming first-year university students in comparison with the writing of ...
Interactions of liquid crystal-forming molecules with phospholipid bilayers studied by molecular dynamics simulations

Recent experiments have shown that liquid crystals can be used to image mammalian cell membranes and to amplify structural reorganization in phospholipid-laden liquid crystal-aqueous interfaces. In this work, molecular dynamics simulations were employed to explore the interactions between commonly used liquid crystal-forming molecules and phospholipid bilayers. In particular, umbrella sampling was used to obtain the potential of mean force of 4-cyano-4′-pentylbiphenyl (5CB) and 4′-(3,4-difluor-phenyl)-4-pentyl-bicylohexyl (5CF) molecules partitioning into a dipalmitoylphosphatidylcholine bilayer. In addition, results of simulations are presented for systems consisting of a fully hydrated bilayer with 5CB or 5CF molecules at the lowest (4.5 mol %) and highest (20 mol %) concentrations used in recent laboratory experiments. It is found that mesogens preferentially partition from the aqueous phase into the membrane; the potential of mean force exhibits highly favorable free energy differences for partitioning (−18 kBT for 5CB and −26 kBT for 5CF). The location and orientation of mesogens associated with the most stable free energies in umbrella sampling simulations of dilute systems were found to be consistent with those observed in liquid-crystal-rich bilayers. It is found that the presence of mesogens in the bilayer enhances the order of lipid acyl tails, and changes the spatial and orientational arrangement of lipid headgroup atoms. These effects are more pronounced at higher liquid-crystal concentrations. In comparing the behavior of 5CB and 5CF, a stronger spatial correlation (i.e., possibly leading to aggregation) is observed between 5CB molecules within a bilayer than between 5CF molecules. Also, the range of molecular orientations and positions along the bilayer normal is larger for 5CB molecules. At the same time, 5CF molecules were found to bind more strongly to lipid headgroups, thereby slowing the lateral motion of lipid molecules.
Fifty years of progress in community mental health in US: the growth of evidence-based practices

Fifty years have elapsed since the passage of the Community Mental Health Centers (CMHC) Act in 1963 that reflected the legislative peak of the community mental healthcare movement in the US Progress of the last 10 years is represented both by expansions of evidence-based practices (EBPs) and the development of emerging practices and fundamental shifts in the orientation of the system stimulated by the consumer-driven recovery movement. Established EBPs have accumulated expanded evidence, new EBPs have been developed and emerging EBPs are gaining increased acceptance. While the lack of widespread implementation of EBPs as well as the limitations of these technologies produces unnecessary suffering and disability, we believe that the growth of evidence for treatments and services justifies optimism for the future.
Brief history of computation of earthquake response spectra

The methods for computation of response spectrum amplitudes are reviewed for the period preceding the modern digital computer age. The mechanical and electrical analog methods that preceded the modern digital calculations were time consuming, inaccurate, and difficult to verify. Modern studies of response and of the nature of strong ground motion became possible after mid-1960 with accumulation of strong-motion records and with accurate digitization and digital data processing.
Human and rodent Alzheimer beta-amyloid peptides acquire distinct conformations in membrane-mimicking solvents.

The major constituent of senile plaques (one of the hallmark lesions of Alzheimer's disease) is a 42(43)-amino-acid polypeptide, termed the A4 or beta-amyloid peptide. The beta-amyloid peptide or A4 is derived from one or more larger beta-amyloid precursor proteins. The precursor protein from whence the A4 peptide is derived is highly conserved throughout evolution, and humans, monkeys, dogs, and bears develop brain deposits of A4 peptide in amyloid fibrils. However, similar accumulations of A4 amyloid are negligible in the brains of rats and mice for reasons that remain unexplored. Notably, the A4 sequence of rodents, deduced from the cDNA clones, differs only in three amino acids from the A4 isolated from the brain of humans. Hence, these differences could account for the inability of rodents to develop Alzheimer-like A4 amyloid plaques. To test this hypothesis directly, using physical and chemical model systems, we synthesized, purified, and characterized A4 peptides corresponding to the human and rodent sequences. Circular dichroic and Fourier-transform infrared spectroscopy were used with various membrane-mimicking solvents, different peptide concentrations, and variable pH to identify those environmental conditions that promoted beta-pleated sheet formation of the human versus rodent A4. At an intermediate alkaline pH ( or = 12). The amount of the beta-structure increased in an octyl glucoside solution, compared to that found in SDS, as well as in several of the other solutions tested here. This suggests that particles originated from prior membrane damage may play a role in the stabilization of beta-pleated sheets with subsequent formation of amyloid deposits. Finally, we found that higher beta-pleated sheet content was observed for the rodent sequences in acetonitrile/water mixtures. In contrast, more beta-pleated sheets were detected with the human A4 in trifluoroethanol/water mixtures at neutral pH. Remarkably, at relatively low peptide concentrations, only the human sequences assumed an extended secondary structure. These data suggest that subtle inter-species amino-acid differences may account for the inability of the rodent peptide to form amyloid fibrils in situ.